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


1

Antiproton Limits on Decaying Gravitino Dark Matter  

E-Print Network [OSTI]

We report on constraints on the lifetime of decaying gravitino dark matter in models with bilinear R-parity violation derived from observations of cosmic-ray antiprotons with the PAMELA experiment. Performing a scan over a viable set of cosmic-ray propagation parameters we find lower limits ranging from $8\\times 10^{28}$s to $6\\times 10^{28}$s for gravitino masses from roughly 100 GeV to 10 TeV. Comparing these limits to constraints derived from gamma-ray and neutrino observations we conclude that the presented antiproton limits are currently the strongest and most robust limits on the gravitino lifetime in the considered mass range. These constraints correspond to upper limits on the size of the bilinear R-parity breaking parameter in the range of $10^{-8}$ to $8\\times 10^{-13}$.

Grefe, Michael

2014-01-01T23:59:59.000Z

2

VEA-0016 - In the Matter of GE Appliances | Department of Energy  

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

6 - In the Matter of GE Appliances 6 - In the Matter of GE Appliances VEA-0016 - In the Matter of GE Appliances Sub-Zero Freezer Co. (Sub-Zero), GE Appliances (GE), and Whirlpool Corporation (Whirlpool) filed appeals of our November 3, 2000 decision, granting Viking Range Corporation (Viking) a six-month exception from the 2001 energy appliance efficiency standards for built-in refrigerators. Viking Range Corp., 28 DOE ¶ 81,002 (2000). As discussed below, we have granted the appeals in part. As a result, the six-month exception will be limited to 475 refrigerators per month and will be subject to a monthly reporting requirement. vea0015-16-17.pdf More Documents & Publications VEH-0015 - In the Matter of Sub-Zero Freezer Co. VEA-0015 - In the Matter of Sub-Zero Freezer Co. VEA-0017 - In the Matter of Whirlpool Corporation

3

Limits on electrophilic Dark Matter from LHC Monojets  

E-Print Network [OSTI]

Searches for WIMP Dark Matter particle at the LHC are considered from the point of view of the existence of a Dark Matter particle which couples primarily through the heavy gauge boson Z, as suggested by recent tentative evidence for a 130 GeV gamma line in the FermiLAT data. We compare three models in which the WIMP is a neutrino-like particle and consider the limits on such particle and interactions from LHC.

K. G. Savvidy

2014-10-22T23:59:59.000Z

4

Pushing Super Materials to the Limit | GE Global Research  

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

to the Limit this Spring Break SpringBreakIt - Pushing Super Materials to the Limit this Spring Break Joseph Vinciquerra 2014.04.23 I lead GE's Materials Processing and Testing...

5

Direct Detection of Sub-GeV Dark Matter  

SciTech Connect (OSTI)

Direct detection strategies are proposed for dark matter particles with MeV to GeV mass. In this largely unexplored mass range, dark matter scattering with electrons can cause single-electron ionization signals, which are detectable with current technology. Ultraviolet photons, individual ions, and heat are interesting alternative signals. Focusing on ionization, we calculate the expected dark matter scattering rates and estimate the sensitivity of possible experiments. Backgrounds that may be relevant are discussed. Theoretically interesting models can be probed with existing technologies, and may even be within reach using ongoing direct detection experiments. Significant improvements in sensitivity should be possible with dedicated experiments, opening up a window to new regions in dark matter parameter space.

Essig, Rouven; Mardon, Jeremy; Volansky, Tomer

2012-03-20T23:59:59.000Z

6

TEE-0074 - In the Matter of GE Appliances & Lighting | Department of Energy  

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

74 - In the Matter of GE Appliances & Lighting 74 - In the Matter of GE Appliances & Lighting TEE-0074 - In the Matter of GE Appliances & Lighting This Decision and Order considers an Application for Exception filed by GE Appliances & Lighting (GE) seeking exception relief from the provision of 10 C.F.R. Part 430, Energy Conservation Program for Consumer Products: Energy Conservation Standards for Refrigerators, Refrigerator-Freezers and Freezers (Refrigerator Efficiency Standards). In its exception request, GE asserts that the firm would suffer a gross inequity if required to adhere to the Refrigerator Efficiency Standards codified at 10 C.F.R. § 430.32. If GE's Application for Exception were granted, GE would receive exception relief from the energy efficiency standard applicable to a new

7

TEE-0077 - In the Matter of GE Appliances & Lighting | Department...  

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

tee0077.pdf More Documents & Publications EXC-12-0010 - In the Matter of DLU Lighting USA EXC-14-0001 - In the Matter of Felix Storch Inc. OHA Product Efficiency Cases Archive...

8

CONSTRAINING THE DISTRIBUTION OF DARK MATTER IN THE INNER GALAXY WITH AN INDIRECT DETECTION SIGNAL: THE CASE OF A TENTATIVE 130 GeV {gamma}-RAY LINE  

SciTech Connect (OSTI)

Dark matter distribution in the very inner region of our Galaxy is still debated. In N-body simulations, a cuspy dark matter halo density profile is favored. Several dissipative baryonic processes, however, are found to be able to significantly flatten dark matter distribution, and a cored dark matter halo density profile is possible. Baryons dominate the gravitational potential in the inner Galaxy, hence a direct constraint on the abundance of dark matter particles is rather challenging. Recently, a few groups have identified a tentative 130 GeV line signal in the Galactic center, which could be interpreted as the signal of dark matter annihilation. Using current 130 GeV line data and adopting the generalized Navarro-Frenk-White profile of the dark matter halo-local dark matter density {rho}{sub 0} = 0.4 GeV cm{sup -3} and r{sub s} = 20 kpc-we obtain a 95% confidence level lower (upper) limit on the inner slope of dark matter density distribution, {alpha} = 1.06 (the cross section of dark matter annihilation into {gamma}-rays ({sigma}v){sub {chi}{chi}{sub {yields}{sub {gamma}{gamma}}}} = 1.3 Multiplication-Sign 10{sup -27} cm{sup 3} s{sup -1}). Such a slope is consistent with the results of some N-body simulations and, if the signal is due to dark matter, suggests that baryonic processes may be unimportant.

Yang Ruizhi; Feng Lei; Li Xiang; Fan Yizhong, E-mail: yzfan@pmo.ac.cn [Key Laboratory of Dark Matter and Space Astronomy, Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China)

2013-06-20T23:59:59.000Z

9

Experimental limits on massive neutrinos from e(+)e(-) annihilations at 29 GeV  

E-Print Network [OSTI]

A search was made in 29-GeV e(+)e(-) annihilations for massive neutrinos decaying to e()X(?)(?) where X is a muon or meson. A 300-pb(-1) data sample yielded just one candidate event with a mass m(e)X>1.8 GeV. Significant limits are found for new...

Baringer, Philip S.; Akerlof, C.; Chapman, J.; Errede, D.; Ken, M. T.; Meyer, D. I.; Neal, H.; Nitz,D.; Thun, R.; Tschirhart, R.; Derrick, M.

1988-02-01T23:59:59.000Z

10

Draft 04/05/09 A new high-background-rejection dark matter Ge cryogenic  

E-Print Network [OSTI]

Draft 04/05/09 A new high-background-rejection dark matter Ge cryogenic detector The EDELWEISS of a cryogenic germanium detector for dark matter search is presented, taking advantage of the coplanar grid in the EURECA project of a one-ton cryogenic detector mass. PACS numbers: 07.57.Kp; 07.85.Nc; 72.20.Jv; 95.35.+d

Boyer, Edmond

11

Unitary neutron matter in the on-shell limit  

E-Print Network [OSTI]

We compute the Bertsch parameter for neutron matter by using nucleon-nucleon interactions that are fully diagonal in momentum space. We analyze the on-shell limit with the similarity renormalization group and compare the results for a simple separable toy model to realistic calculations with high precision $NN$ potentials.

Enrique Ruiz Arriola; Sergio Szpigel; Varese Salvador Timoteo

2014-12-05T23:59:59.000Z

12

Strong Upper Limits on Sterile Neutrino Warm Dark Matter  

SciTech Connect (OSTI)

Sterile neutrinos are attractive dark matter candidates. Their parameter space of mass and mixing angle has not yet been fully tested despite intensive efforts that exploit their gravitational clustering properties and radiative decays. We use the limits on gamma-ray line emission from the Galactic center region obtained with the SPI spectrometer on the INTEGRAL satellite to set new constraints, which improve on the earlier bounds on mixing by more than 2 orders of magnitude, and thus strongly restrict a wide and interesting range of models.

Yueksel, Hasan [Department of Physics, Ohio State University, Columbus, Ohio 43210 (United States); Center for Cosmology and Astro-Particle Physics, Ohio State University, Columbus, Ohio 43210 (United States); Beacom, John F. [Department of Physics, Ohio State University, Columbus, Ohio 43210 (United States); Center for Cosmology and Astro-Particle Physics, Ohio State University, Columbus, Ohio 43210 (United States); Department of Astronomy, Ohio State University, Columbus, Ohio 43210 (United States); Watson, Casey R. [Department of Physics and Astronomy, Millikin University, Decatur, Illinois 62522 (United States)

2008-09-19T23:59:59.000Z

13

Dark Matter Spin-Dependent Limits for WIMP Interactions on 19-F by PICASSO  

E-Print Network [OSTI]

The PICASSO experiment at SNOLAB reports new results for spin-dependent WIMP interactions on $^{19}$F using the superheated droplet technique. A new generation of detectors and new features which enable background discrimination via the rejection of non-particle induced events are described. First results are presented for a subset of two detectors with target masses of $^{19}$F of 65 g and 69 g respectively and a total exposure of 13.75 $\\pm$ 0.48 kgd. No dark matter signal was found and for WIMP masses around 24 GeV/c$^2$ new limits have been obtained on the spin-dependent cross section on $^{19}$F of $\\sigma_F$ = 13.9 pb (90% C.L.) which can be converted into cross section limits on protons and neutrons of $\\sigma_p$ = 0.16 pb and $\\sigma_n$ = 2.60 pb respectively (90% C.L). The obtained limits on protons restrict recent interpretations of the DAMA/LIBRA annual modulations in terms of spin-dependent interactions.

S. Archambault; F. Aubin; M. Auger; E. Behnke; B. Beltran; K. Clark; X. Dai; A. Davour; J. Farine; R. Faust; M. -H. Genest; G. Giroux; R. Gornea; C. Krauss; S. Kumaratunga; I. Lawson; C. Leroy; L. Lessard; C. Levy; I. Levine; R. MacDonald; J. -P. Martin; P. Nadeau; A. Noble; M. -C. Piro; S. Pospisil; T. Shepherd; N. Starinski; I. Stekl; C. Storey; U. Wichoski; V. Zacek

2009-07-02T23:59:59.000Z

14

Fitting the Fermi-LAT GeV excess: on the importance of the propagation of electrons from dark matter  

E-Print Network [OSTI]

An excess of gamma rays at GeV energies has been detected in the Fermi-LAT data. This signal comes from a narrow region around the Galactic Center and has been interpreted as possible evidence for light (30 GeV) dark matter particles. Focussing on the prompt gamma-ray emission, previous works found that the best fit to the data corresponds to annihilations proceeding into b quarks, with a dark matter profile going as r^{-1.2}. We show that this is not the only possible annihilation set-up. More specifically, we show how including the contributions to the gamma-ray spectrum from inverse Compton scattering and bremsstrahlung from electrons produced in dark matter annihilations, and undergoing diffusion through the Galactic magnetic field, significantly affects the spectrum for leptonic final states. This drastically changes the interpretation of the excess in terms of dark matter.

Lacroix, Thomas

2015-01-01T23:59:59.000Z

15

GeV Gamma-ray Flux Upper Limits from Clusters of Galaxies  

E-Print Network [OSTI]

The detection of diffuse radio emission associated with clusters of galaxies indicates populations of relativistic leptons infusing the intracluster medium. Those electrons and positrons are either injected into and accelerated directly in the intracluster medium, or produced as secondary pairs by cosmic-ray ions scattering on ambient protons. Radiation mechanisms involving the energetic leptons together with decay of neutral pions produced by hadronic interactions have the potential to produce abundant GeV photons. Here, we report on the search for GeV emission from clusters of galaxies using data collected by the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope (Fermi) from August 2008 to February 2010. Thirty-three galaxy clusters have been selected according to their proximity and high mass, X-ray flux and temperature, and indications of non-thermal activity for this study. We report upper limits on the photon flux in the range 0.2-100 GeV towards a sample of observed clusters (typical va...

al., M Ackermann et

2010-01-01T23:59:59.000Z

16

Backgrounds and Projected Limits from Dark Matter Direct Detection Experiments  

E-Print Network [OSTI]

A simple formula is introduced which indicates the amount by which projections of dark matter direct detection experiments are expected to be degraded due to backgrounds.

Scott Dodelson

2008-12-08T23:59:59.000Z

17

Investigation of the kinetics of surface-limited thin film growth of SiGe alloys  

SciTech Connect (OSTI)

The kinetics of surface-limited thin film growth of SiGe alloys was investigated by time-resolved surface differential reflectometry. The source gas, mixtures of disilane and digermane in ratios from 1:1 to 6:1 in helium carrier gas, was delivered to a heated substrate by a fast-acting pulsed molecular jet valve. The adsorption and desorption kinetics were determined from the surface differential reflectance signal obtained using a polarized, high-stability HeNe probe laser. Thin film growth was studied in the temperature range of 400--600{degrees}C on Si(001) substrates. Preferential incorporation of digermane into the film produces an alloy composition that depends upon but does not mirror the gas composition. For all gas mixtures, there is a strong temperature dependence of the rate at which the adsorption layer decomposes into film plus by-product. The kinetic data and the alloy compositions provide a basis for deducing some of the characteristics of the reaction sequence that leads to SiGe alloy thin film growth.

Sharp, J.W. [Tennessee Univ., Knoxville, TN (United States). Dept. of Physics and Astronomy; Eres, G. [Oak Ridge National Lab., TN (United States)

1992-11-01T23:59:59.000Z

18

Investigation of the kinetics of surface-limited thin film growth of SiGe alloys  

SciTech Connect (OSTI)

The kinetics of surface-limited thin film growth of SiGe alloys was investigated by time-resolved surface differential reflectometry. The source gas, mixtures of disilane and digermane in ratios from 1:1 to 6:1 in helium carrier gas, was delivered to a heated substrate by a fast-acting pulsed molecular jet valve. The adsorption and desorption kinetics were determined from the surface differential reflectance signal obtained using a polarized, high-stability HeNe probe laser. Thin film growth was studied in the temperature range of 400--600[degrees]C on Si(001) substrates. Preferential incorporation of digermane into the film produces an alloy composition that depends upon but does not mirror the gas composition. For all gas mixtures, there is a strong temperature dependence of the rate at which the adsorption layer decomposes into film plus by-product. The kinetic data and the alloy compositions provide a basis for deducing some of the characteristics of the reaction sequence that leads to SiGe alloy thin film growth.

Sharp, J.W. (Tennessee Univ., Knoxville, TN (United States). Dept. of Physics and Astronomy); Eres, G. (Oak Ridge National Lab., TN (United States))

1992-11-01T23:59:59.000Z

19

Limits on spin-dependent wimp-nucleon interactions from the cryogenic dark matter search  

SciTech Connect (OSTI)

The Cryogenic Dark Matter Search (CDMS) is an experiment to detect weakly interacting massive particles (WIMPs) based on their interactions with Ge and Si nuclei. We report the results of an analysis of data from the first two runs of CDMS at the Soudan Underground Laboratory in terms of spin-dependent WIMP-nucleon interactions on {sup 73}Ge and {sup 29}Si. These data exclude new regions of spin-dependent WIMP-nucleon interaction parameter space, including regions relevant to spin-dependent interpretations of the annual modulation signal reported by the DAMA/NaI experiment.

Akerib, D.S.; Armel-Funkhouser, M.S.; Attisha, M.J.; Bailey, C.N.; Baudis, L.; Bauer, Daniel A.; Brink, P.L.; Brusov, P.P.; Bunker, R.; Cabrera, B.; Caldwell, D.O.; Chang, C.L.; Cooley, J.; Crisler, M.B.; Cushman, P.; Daal, M.; DeJongh, F.; Dixon, R.; Dragowsky, M.R.; Driscoll, D.D.; Duong, L.; /Case Western Reserve U. /UC, Berkeley /Brown U.

2005-09-01T23:59:59.000Z

20

Limits on a muon flux from Kaluza-Klein dark matter annihilations in the Sun from the IceCube 22-string detector  

SciTech Connect (OSTI)

A search for muon neutrinos from Kaluza-Klein dark matter annihilations in the Sun has been performed with the 22-string configuration of the IceCube neutrino detector using data collected in 104.3 days of live-time in 2007. No excess over the expected atmospheric background has been observed. Upper limits have been obtained on the annihilation rate of captured lightest Kaluza-Klein particle (LKP) WIMPs in the Sun and converted to limits on the LKP-proton cross-sections for LKP masses in the range 250 - 3000 GeV. These results are the most stringent limits to date on LKP annihilation in the Sun.

IceCube Collaboration; Abbasi, R.; al., et

2009-10-23T23:59:59.000Z

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


21

Limits on a muon flux from Kaluza-Klein dark matter annihilations in the Sun from the IceCube 22-string detector  

Science Journals Connector (OSTI)

A search for muon neutrinos from Kaluza-Klein dark matter annihilations in the Sun has been performed with the 22-string configuration of the IceCube neutrino detector using data collected in 104.3 days of live time in 2007. No excess over the expected atmospheric background has been observed. Upper limits have been obtained on the annihilation rate of captured lightest Kaluza-Klein particle (LKP) WIMPs in the Sun and converted to limits on the LKP-proton cross sections for LKP masses in the range 2503000GeV. These results are the most stringent limits to date on LKP annihilation in the Sun.

R. Abbasi et al. (IceCube Collaboration)

2010-03-29T23:59:59.000Z

22

Extending the Sensitivity to the Detection of WIMP Dark Matter with an Improved Understanding of the Limiting Neutron Backgrounds  

SciTech Connect (OSTI)

The Cryogenic Dark Matter Search (CDMS) uses position-sensitive Germanium and Silicon crystals in the direct detection of Weakly Interacting Massive Particles (WIMPs) believed to constitute most of the dark matter in the Universe. WIMP interactions with matter being rare, identifying and eliminating known backgrounds is critical for detection. Event-by-event discrimination by the detectors rejects the predominant gamma and beta backgrounds while Monte Carlo simulations help estimate, and subtract, the contribution from the neutrons. This thesis describes the effort to understand neutron backgrounds as seen in the two stages of the CDMS search for WIMPs. The first stage of the experiment was at a shallow site at the Stanford Underground Facility where the limiting background came from high-energy neutrons produced by cosmic-ray muon interactions in the rock surrounding the cavern. Simulations of this background helped inform the analysis of data from an experimental run at this site and served as input for the background reduction techniques necessary to set new exclusion limits on the WIMP-nucleon cross-section, excluding new parameter space for WIMPs of masses 8-20 GeV/c{sup 2}. This thesis considers the simulation methods used as well as how various event populations in the data served as checks on the simulations to allow them to be used in the interpretation of the WIMP-search data. The studies also confirmed the presence of a limiting neutron background at the shallow site, necessitating the move to the 713-meter deep Soudan Underground Facility. Similar computer-based studies helped quantify the neutron background seen at the deeper site and informed the analysis of the data emerging from the first physics run of the experiment at Soudan. In conjunction with the WIMP-search and calibration data, the simulations confirmed that increased depth considerably reduced the neutron backgrounds seen, greatly improving the sensitivity to WIMP detection. The data run set an upper limit of 4 x 10{sup -43} on the WIMP-nucleon cross section for a WIMP mass of 60 GeV/c{sup 2} . Upper limits to the rate of background neutrons have also been determined.

Kamat, Sharmila; /Case Western Reserve U.; ,

2005-01-01T23:59:59.000Z

23

Kinetics of hydrogen desorption in surface-limited thin-film growth of SiGe alloys  

SciTech Connect (OSTI)

The kinetics of hydrogen desorption in surface-limited thin-film growth of SiGe alloys from binary mixtures of disilane and digermane was investigated by surface differential reflectance. The hydrogen desorption process from the alloy surface was found to consist of two components. Both components are thermally activated, but the activation energies appear to equal neither the hydrogen desorption energy from pure silicon nor that from pure germanium surfaces. We suggest that the two components represent Ge- and Si-mediated hydrogen desorption, with the former being more rapid than the latter.

Sharp, J.W. (Department of Physics and Astronomy, The University of Tennessee, Knoxville, Tennessee 37996 (United States)); Eres, G. (Oak Ridge National Laboratory, P. O. Box 2008, Solid State Division, Bldg. 2000 MS 6056, Oak Ridge, Tennessee 37831-6056 (United States))

1993-05-31T23:59:59.000Z

24

Indirect Dark Matter Detection Limits from the Ultra-Faint Milky Way Satellite Segue 1  

SciTech Connect (OSTI)

We use new kinematic data from the ultra-faint Milky Way satellite Segue 1 to model its dark matter distribution and derive upper limits on the dark matter annihilation cross-section. Using gamma-ray ux upper limits from the Fermi satellite and MAGIC, we determine cross-section exclusion regions for dark matter annihilation into a variety of different particles including charged leptons. We show that these exclusion regions are beginning to probe the regions of interest for a dark matter interpretation of the electron and positron uxes from PAMELA, Fermi, and HESS, and that future observations of Segue 1 have strong prospects for testing such an interpretation. We additionally discuss prospects for detecting annihilation with neutrinos using the IceCube detector, finding that in an optimistic scenario a few neutrino events may be detected. Finally we use the kinematic data to model the Segue 1 dark matter velocity dispersion and constrain Sommerfeld enhanced models.

Essig, Rouven; /SLAC; Sehgal, Neelima; Strigari, Louis E.; /KIPAC, Menlo Park /Stanford U., Phys. Dept.; Geha, Marla; /Yale U.; Simon, Joshua D.; /Carnegie Inst. Observ.

2011-08-11T23:59:59.000Z

25

Updated cosmic-ray and radio constraints on light dark matter: Implications for the GeV gamma-ray excess at the Galactic center  

E-Print Network [OSTI]

The apparent gamma-ray excess in the Galactic center region and inner Galaxy has attracted considerable interest, notably because both its spectrum and radial distribution are consistent with an interpretation in terms of annihilating dark matter particles with a mass of about 10-40 GeV. We confront such an interpretation with an updated compilation of various indirect dark matter detection bounds, which we adapt to the specific form required by the observed signal. We find that cosmic-ray positron data strongly rule out dark matter annihilating to light leptons, or 'democratically' to all leptons, as an explanation of the signal. Cosmic-ray antiprotons, for which we present independent and significantly improved limits with respect to previous estimates, are already in considerable tension with DM annihilation to any combination of quark final states; the first set of AMS-02 data will thus be able to rule out or confirm the DM hypothesis with high confidence. For reasonable assumptions about the magnetic field in the Galactic center region, radio observations independently put very severe constraints on a DM interpretation of the excess, in particular for all leptonic annihilation channels.

Torsten Bringmann; Martin Vollmann; Christoph Weniger

2014-06-23T23:59:59.000Z

26

Pushing the Performance Limits of SiGe HBTTechnology Marwan Khatera  

E-Print Network [OSTI]

noise, device matching,and power performance.The performance evolution ofSiGe HBT technologyin recent. ECS Transactions, 3 (7) 341-353 (2006) 10.1149/1.2355832, copyright The Electrochemical Society 341

Rieh, Jae-Sung

27

Limits on spin-independent wimp-nucleon interactions from the two-tower run of the cryogenic dark matter search  

SciTech Connect (OSTI)

We report new results from the Cryogenic Dark Matter Search (CDMS II) at the Soudan Underground Laboratory. Two towers, each consisting of six detectors, were operated for 74.5 live days, giving spectrum-weighted exposures of 34 kg-d for germanium and 12 kg-d for silicon targets after cuts, averaged over recoil energies 10-100 keV for a WIMP mass of 60GeV/c{sup 2}. A blind analysis was conducted, incorporating improved techniques for rejecting surface events. No WIMP signal exceeding expected backgrounds was observed. When combined with our previous results from Soudan, the 90% C.L. upper limit on the spin-independent WIMP-nucleon cross section is 1.6 x 10{sup -43} cm{sup 2} from Ge, and 3 x 10{sup -42} cm{sup 2} from Si, for a WIMP mass of 60GeV/c{sup 2}. The combined limit from Ge (Si) is a factor of 2.5 (10) lower than our previous results, and constrains predictions of supersymmetric models.

Akerib, D.S.; Attisha, M.J.; Bailey, C.N.; Baudis, L.; Bauer, Daniel A.; Brink, P.L.; Brusov, P.P.; Bunker, R.; Cabrera, B.; Caldwell, D.O.; Chang, C.L.; Cooley, J.; Crisler, M.B.; Cushman, P.; Daal, M.; Dixon, R.; Dragowsky, M.R.; Driscoll, D.D.; Duong, L.; Ferril, R.; Filippini, J.; /Brown U. /Case Western Reserve U. /Fermilab /LBL, Berkeley

2005-09-01T23:59:59.000Z

28

Nuclear spin structure in dark matter search: The finite momentum transfer limit  

E-Print Network [OSTI]

Spin-dependent elastic scattering of weakly interacting massive dark matter particles (WIMP) off nuclei is reviewed. All available, within different nuclear models, structure functions S(q) for finite momentum transfer (q>0) are presented. These functions describe the recoil energy dependence of the differential event rate due to the spin-dependent WIMP-nucleon interactions. This paper, together with the previous paper ``Nuclear spin structure in dark matter search: The zero momentum transfer limit'', completes our review of the nuclear spin structure calculations involved in the problem of direct dark matter search.

V. A. Bednyakov; F. Simkovic

2006-08-09T23:59:59.000Z

29

First limit from a surface run of a 10 liter Dark Matter Time Projection Chamber  

E-Print Network [OSTI]

A 10 liter prototype Dark Matter Time Projection Chamber (DMTPC) is operated on the surface of the earth at 75 Torr using carbon-tetrafluoride (CF4) as a target material to obtain a 24.57 gram-day exposure. A limit is set ...

Caldwell, Thomas S., Jr

2009-01-01T23:59:59.000Z

30

A new high-background-rejection dark matter Ge cryogenic detector  

E-Print Network [OSTI]

A new design of a cryogenic germanium detector for dark matter search is presented, taking advantage of the coplanar grid technique of event localisation for improved background discrimination. Experiments performed with prototype devices in the EDELWEISS II setup at the Modane underground facility demonstrate the remarkably high efficiency of these devices for the rejection of low-energy $\\beta$, approaching 10$^5$ . This opens the road to investigate the range beyond 10$^{-8}$ pb in the WIMP-nucleon collision cross-sections, as proposed in the EURECA project of a one-ton cryogenic detector mass.

Broniatowski, A; Armengaud, E; Berg, L; Benot, A; Besida, O; Blumer, J; Chantelauze, A; Chapellier, M; Chardin, G; Charlieux, F; Collin, S; Crauste, O; De Jsus, M; Di Stefano, P; Dolgorouki, Y; Domange, J; Dumoulin, L; Eitel, K; Gascon, J; Gerbier, G; Gros, M; Hannawald, M; Herv, S; Juillard, A; Kluck, H; Kozlov, V; Lemrani, R; Lubashevskiy, A; Marrache, C; Marnieros, S; Navick, X -F; Nones, C; Olivieri, E; Pari, P; Paul, B; Rozov, S; Sanglard, V; Scorza, S; Semikh, S; Verdier, M -A; Vagneron, L; Yakushev, E

2009-01-01T23:59:59.000Z

31

Limits for the Central Production of ?+ and ?--Pentaquarks in 920-GeV pA Collisions  

Science Journals Connector (OSTI)

We have searched for ?+(1540) and ?--(1862) pentaquark candidates in proton-inducedreactions on C, Ti, and W targets at midrapidity and s=41.6??GeV. In 2108 inelastic eventswe find no evidence for narrow (??5??MeV) signals in the ?+?pKS0 and ?--??-?- channels; our 95% C.L. upper limits (UL) forthe inclusive production cross section times branching fraction B?d?/dy|y?0 are (416)?b/N for a ?+ mass between 1521 and 1555MeV,and 2.5?b/N for the ?--. The UL of the yield ratio of ?+/?(1520)<(312)% is significantly lower than model predictions.Our UL of B??--/?(1530)0<4% is at variance with the results that have provided the first evidencefor the ?--.

I. Abt et al. (HERA-B Collaboration)

2004-11-18T23:59:59.000Z

32

Axion Dark Matter searches and New Limits on CPT and Lorentz-Invariance-violating interactions  

E-Print Network [OSTI]

We calculate the proton and neutron spin contributions for a wide range of nuclei using semi-empirical methods. These values are required for interpretations of searches for exotic nuclear spin-dependent couplings, including those that arise in dark matter detection schemes, which search for axions, WIMPs and topological defects, as well as tests of CPT and Lorentz-invariance violation. We reconsider experiments, which search for evidence of CPT and Lorentz-invariance-violating couplings, using a $^{3}$He/$^{129}$Xe comagnetometer and show that the $^{3}$He/$^{129}$Xe system is in fact particularly sensitive to proton interaction parameters. From existing data, we derive a limit on the CPT and Lorentz-invariance-violating parameter $|\\tilde{b}_{\\perp}^p| nuclear anapole moment data for Cs to obtain new limits on several other CPT and Lorentz-invariance-violating parameters.

Y. V. Stadnik; V. V. Flambaum

2014-08-10T23:59:59.000Z

33

WIMP Dark Matter Limit-Direct Detection Data and Sensitivity Plots from the Cryogenic Dark Matter Search II and the University of California at Santa Barbara  

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

Expectations for non-baryonic dark matter are founded principally in Big Bang nucleosynthesis calculations, which indicate that the missing mass of the universe is not likely to be baryonic. The supersymmetric standard model (SUSY) offers a promising framework for expectations of particle species which could satisfy the observed properties of dark matter. WIMPs are the most likely SUSY candidate for a dark matter particle. The High Energy Physics Group at University of California, Santa Barbara, is part of the CDMSII Collaboration and have provided the Interactive Plotter for WIMP Dark Matter Limit-Direct Detection Data on their website. They invite other collaborations working on dark matter research to submit datasets and, as a result, have more than 150 data sets now available for use with the plotting tool. The published source of the data is provided with each data set.

34

Fermi 130 GeV gamma-ray excess and dark matter annihilation in sub-haloes and in the Galactic centre  

SciTech Connect (OSTI)

We analyze publicly available Fermi-LAT high-energy gamma-ray data and confirm the existence of clear spectral feature peaked at E{sub ?} = 130 GeV. Scanning over the Galaxy we identify several disconnected regions where the observed excess originates from. Our best optimized fit is obtained for the central region of Galaxy with a clear peak at 130 GeV with local statistical significance 4.5?. The observed excess is not correlated with Fermi bubbles. We compute the photon spectra induced by dark matter annihilations into two and four standard model particles, the latter via two light intermediate states, and fit the spectra with data. Since our fits indicate sharper and higher signal peak than in the previous works, data favors dark matter direct two-body annihilation channels into photons or other channels giving only line-like spectra. If Einasto halo profile correctly predicts the central cusp of Galaxy, dark matter annihilation cross-section to two photons is of order ten percent of the standard thermal freeze-out cross-section. The large dark matter two-body annihilation cross-section to photons may signal a new resonance that should be searched for at the CERN LHC experiments.

Tempel, Elmo; Hektor, Andi; Raidal, Martti, E-mail: elmo@aai.ee, E-mail: andi.hektor@cern.ch, E-mail: martti.raidal@cern.ch [NICPB, Ravala 10, Tallinn 10143 (Estonia)

2012-09-01T23:59:59.000Z

35

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

E-Print Network [OSTI]

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

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

1998-02-18T23:59:59.000Z

36

Limits on a muon flux from Kaluza-Klein dark matter annihilations in the Sun from the IceCube 22-string detector  

E-Print Network [OSTI]

Limits on a muon flux from Kaluza-Klein dark matterAPS/123-QED Limits on a muon ?ux from Kaluza-Klein dark23, 2009) A search for muon neutrinos from Kaluza-Klein dark

Abbasi, R.

2010-01-01T23:59:59.000Z

37

Limiter  

DOE Patents [OSTI]

A limiter with a specially contoured front face is provided. The front face of the limiter (the plasma-side face) is flat with a central indentation. In addition, the limiter shape is cylindrically symmetric so that the limiter can be rotated for greater heat distribution. This limiter shape accommodates the various power scrape-off distances lambda p, which depend on the parallel velocity, V/sub parallel/, of the impacting particles.

Cohen, S.A.; Hosea, J.C.; Timberlake, J.R.

1984-10-19T23:59:59.000Z

38

Limiter  

DOE Patents [OSTI]

A limiter with a specially contoured front face accommodates the various power scrape-off distances .lambda..sub.p, which depend on the parallel velocity, V.sub..parallel., of the impacting particles. The front face of the limiter (the plasma-side face) is flat with a central indentation. In addition, the limiter shape is cylindrically symmetric so that the limiter can be rotated for greater heat distribution.

Cohen, Samuel A. (Hopewell, NJ); Hosea, Joel C. (Princeton, NJ); Timberlake, John R. (Allentown, NJ)

1986-01-01T23:59:59.000Z

39

Compact stars with a small electric charge: the limiting radius to mass relation and the maximum mass for incompressible matter  

E-Print Network [OSTI]

One of the stiffest equations of state for matter in a compact star is constant energy density and this generates the interior Schwarzschild radius to mass relation and the Misner maximum mass for relativistic compact stars. If dark matter populates the interior of stars, and this matter is supersymmetric or of some other type, some of it possessing a tiny electric charge, there is the possibility that highly compact stars can trap a small but non-negligible electric charge. In this case the radius to mass relation for such compact stars should get modifications. We use an analytical scheme to investigate the limiting radius to mass relation and the maximum mass of relativistic stars made of an incompressible fluid with a small electric charge. The investigation is carried out by using the hydrostatic equilibrium equation, i.e., the Tolman-Oppenheimer-Volkoff (TOV) equation, together with the other equations of structure, with the further hypothesis that the charge distribution is proportional to the energy density. The approach relies on Volkoff and Misner's method to solve the TOV equation. For zero charge one gets the interior Schwarzschild limit, and supposing incompressible boson or fermion matter with constituents with masses of the order of the neutron mass one gets that the maximum mass is the Misner mass. For a small electric charge, our analytical approximating scheme valid in first order in the star's electric charge, shows that the maximum mass increases relatively to the uncharged case, whereas the minimum possible radius decreases, an expected effect since the new field is repulsive aiding the pressure to sustain the star against gravitational collapse.

Jos P. S. Lemos; Francisco J. Lopes; Gonalo Quinta; Vilson T. Zanchin

2015-01-09T23:59:59.000Z

40

On the capture of dark matter by neutron stars  

E-Print Network [OSTI]

We calculate the number of dark matter particles that a neutron star accumulates over its lifetime as it rotates around the center of a galaxy, when the dark matter particle is a self-interacting boson but does not self-annihilate. We take into account dark matter interactions with baryonic matter and the time evolution of the dark matter sphere as it collapses within the neutron star. We show that dark matter self-interactions play an important role in the rapid accumulation of dark matter in the core of the neutron star. We consider the possibility of determining an exclusion region of the parameter space for dark matter mass and dark matter interaction cross sections based on the observation of old neutron stars with strong dark matter self-interactions. We show that for a dark matter density of $~10^3$ GeV/cm$^3$ and dark matter mass $m_\\chi$ less than approximately 10 GeV, there is a potential exclusion region for dark matter interactions with nucleons that is three orders of magnitude more stringent than without self-interactions. The potential exclusion region for dark matter self-interaction cross sections is many orders of magnitude stronger than the current Bullet Cluster limit. For example, for high dark matter density regions, we find that for $m_\\chi\\sim 10$ GeV when the dark matter interaction cross section with the nucleons ranges from $\\sigma_{\\chi n}\\sim 10^{-52}$ cm$^2$ to $10^{-57}$ cm$^2$, the dark matter self-interaction cross section limit is $\\sigma_{\\chi\\chi}ten orders of magnitude stronger than the Bullet Cluster limit.

Tolga Guver; Arif Emre Erkoca; Mary Hall Reno; Ina Sarcevic

2014-04-09T23:59:59.000Z

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


41

LHC Bounds on Interactions of Dark Matter  

E-Print Network [OSTI]

We derive limits on the interactions of dark matter with quarks from ATLAS null searches for jets + missing energy based on ~1 fb^-1 of integrated luminosity, using a model-insensitive effective theory framework. We find that the new limits from the LHC significantly extend limits previously derived from CDF data at the Tevatron. Translated into the parameter space of direct searches, these limits are particularly effective for ~GeV mass WIMPs. Our limits indicate tension with isospin violating models satisfying minimal flavor violation which attempt to reconcile the purported CoGeNT excess with Xenon-100, indicating that either a light mediator or nontrivial flavor structure for the dark sector is necessary for a viable reconciliation of CoGeNT with Xenon.

Arvind Rajaraman; William Shepherd; Tim M. P. Tait; Alexander M. Wijangco

2011-08-04T23:59:59.000Z

42

LHC bounds on interactions of dark matter  

Science Journals Connector (OSTI)

We derive limits on the interactions of dark matter with quarks from ATLAS null searches for jets+missing energy based on ?1??fb-1 of integrated luminosity, using a model-insensitive effective theory framework. We find that the new limits from the LHC significantly extend limits previously derived from CDF data at the Tevatron. Translated into the parameter space of direct searches, these limits are particularly effective for ???GeV mass weakly interacting massive particles. Our limits indicate tension with isospin-violating models satisfying minimal flavor violation which attempt to reconcile the purported CoGeNT excess with Xenon-100, indicating that either a light mediator or nontrivial flavor structure for the dark sector is necessary for a viable reconciliation of CoGeNT with Xenon.

Arvind Rajaraman; William Shepherd; Tim M. P. Tait; Alexander M. Wijangco

2011-11-09T23:59:59.000Z

43

Limits on Dark Matter Annihilation Signals from the Fermi LAT 4-year Measurement of the Isotropic Gamma-Ray Background  

E-Print Network [OSTI]

We search for evidence of dark matter (DM) annihilation in the isotropic gamma-ray background (IGRB) measured with 50 months of Fermi Large Area Telescope (LAT) observations. An improved theoretical description of the cosmological DM annihilation signal, based on two complementary techniques and assuming generic weakly interacting massive particle (WIMP) properties, renders more precise predictions compared to previous work. More specifically, we estimate the cosmologically-induced gamma-ray intensity to have an uncertainty of a factor ~20 in canonical setups. We consistently include both the Galactic and extragalactic signals under the same theoretical framework, and study the impact of the former on the IGRB spectrum derivation. We find no evidence for a DM signal and we set limits on the DM-induced isotropic gamma-ray signal. Our limits are competitive for DM particle masses up to tens of TeV and, indeed, are the strongest limits derived from Fermi LAT data at TeV energies. This is possible thanks to the n...

Ackermann, M; Albert, A; Baldini, L; Barbiellini, G; Bastieri, D; Bechtol, K; Bellazzini, R; Bissaldi, E; Bloom, E D; Bonino, R; Bregeon, J; Bruel, P; Buehler, R; Buson, S; Caliandro, G A; Cameron, R A; Caragiulo, M; Caraveo, P A; Cecchi, C; Charles, E; Chekhtman, A; Chiang, J; Chiaro, G; Ciprini, S; Claus, R; Cohen-Tanugi, J; Conrad, J; Cuoco, A; Cutini, S; D'Ammando, F; de Angelis, A; de Palma, F; Dermer, C D; Digel, S W; Drell, P S; Drlica-Wagner, A; Favuzzi, C; Ferrara, E C; Franckowiak, A; Fukazawa, Y; Funk, S; Fusco, P; Gargano, F; Gasparrini, D; Giglietto, N; Giordano, F; Giroletti, M; Godfrey, G; Guiriec, S; Gustafsson, M; Hewitt, J W; Hou, X; Kamae, T; Kuss, M; Larsson, S; Latronico, L; Longo, F; Loparco, F; Lovellette, M N; Lubrano, P; Malyshev, D; Massaro, F; Mayer, M; Mazziotta, M N; Michelson, P F; Mitthumsiri, W; Mizuno, T; Monzani, M E; Morselli, A; Moskalenko, I V; Murgia, S; Negro, M; Nemmen, R; Nuss, E; Ohsugi, T; Orienti, M; Orlando, E; Ormes, J F; Paneque, D; Perkins, J S; Pesce-Rollins, M; Piron, F; Pivato, G; Raino, S; Rando, R; Razzano, M; Reimer, A; Reimer, O; Sanchez-Conde, M; Schulz, A; Sgro, C; Siskind, E J; Spandre, G; Spinelli, P; Strong, A W; Suson, D J; Tajima, H; Takahashi, H; Thayer, J G; Thayer, J B; Tibaldo, L; Tinivella, M; Torres, D F; Troja, E; Uchiyama, Y; Vianello, G; Werner, M; Winer, B L; Wood, K S; Wood, M; Zaharijas, G

2015-01-01T23:59:59.000Z

44

A Comprehensive Search for Dark Matter Annihilation in Dwarf Galaxies  

E-Print Network [OSTI]

We present a new formalism designed to discover dark matter annihilation occurring in the Milky Way's dwarf galaxies. The statistical framework extracts all available information in the data by simultaneously combining observations of all the dwarf galaxies and incorporating the impact of particle physics properties, the distribution of dark matter in the dwarfs, and the detector response. The method performs maximally powerful frequentist searches and produces confidence limits on particle physics parameters. Probability distributions of test statistics under various hypotheses are constructed exactly, without relying on large sample approximations. The derived limits have proper coverage by construction and claims of detection are not biased by imperfect background modeling. We implement this formalism using data from the Fermi Gamma-ray Space Telescope to search for an annihilation signal in the complete sample of Milky Way dwarfs whose dark matter distributions can be reliably determined. We find that the observed data is consistent with background for each of the dwarf galaxies individually as well as in a joint analysis. The strongest constraints are at small dark matter particle masses. Taking the median of the systematic uncertainty in dwarf density profiles, the cross section upper limits are below the pure s-wave weak scale relic abundance value (2.2 x 10^-26 cm^3/s) for dark matter masses below 26 GeV (for annihilation into b quarks), 29 GeV (tau leptons), 35 GeV (up, down, strange, charm quarks and gluons), 6 GeV (electrons/positrons), and 114 GeV (two-photon final state). For dark matter particle masses less than 1 TeV, these represent the strongest limits obtained to date using dwarf galaxies.

Alex Geringer-Sameth; Savvas M. Koushiappas; Matthew G. Walker

2014-10-08T23:59:59.000Z

45

Dark-matter admixed white dwarfs  

Science Journals Connector (OSTI)

We study the equilibrium structures of white dwarfs with dark matter cores formed by non-self-annihilating dark matter (DM) particles with masses ranging from 1GeV to 100GeV, which are assumed to form an ideal degenerate Fermi gas inside the stars. For DM particles of mass 10GeV and 100GeV, we find that stable stellar models exist only if the mass of the DM core inside the star is less than O(10-3)M? and O(10-6)M?, respectively. The global properties of these stars, and in particular the corresponding Chandrasekhar mass limits, are essentially the same as those of traditional white dwarf models without DM. Nevertheless, in the 10GeV case, the gravitational attraction of the DM core is strong enough to squeeze the normal matter in the core region to densities above neutron drip, far above those in traditional white dwarfs. For DM with a particle mass of 1GeV, the DM core inside the star can be as massive as ?0.1M? and affects the global structure of the star significantly. In this case, the radius of a stellar model with DM can be about two times smaller than that of a traditional white dwarf. Furthermore, the Chandrasekhar mass limit can also be decreased by as much as 40%. Our results may have implications on the extent to which type Ia supernovae can be regarded as standard candlesa key assumption in the discovery of dark energy.

S.-C. Leung; M.-C. Chu; L.-M. Lin; K.-W. Wong

2013-06-07T23:59:59.000Z

46

VEA-0015 - In the Matter of Sub-Zero Freezer Co. | Department of Energy  

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

5 - In the Matter of Sub-Zero Freezer Co. 5 - In the Matter of Sub-Zero Freezer Co. VEA-0015 - In the Matter of Sub-Zero Freezer Co. Sub-Zero Freezer Co. (Sub-Zero), GE Appliances (GE), and Whirlpool Corporation (Whirlpool) filed appeals of our November 3, 2000 decision, granting Viking Range Corporation (Viking) a six-month exception from the 2001 energy appliance efficiency standards for built-in refrigerators. Viking Range Corp., 28 DOE ¶ 81,002 (2000). As discussed below, we have granted the appeals in part. As a result, the six-month exception will be limited to 475 refrigerators per month and will be subject to a monthly reporting requirement. vea0015-16-17.pdf More Documents & Publications VEH-0015 - In the Matter of Sub-Zero Freezer Co. VEA-0017 - In the Matter of Whirlpool Corporation

47

VEA-0017 - In the Matter of Whirlpool Corporation | Department of Energy  

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

7 - In the Matter of Whirlpool Corporation 7 - In the Matter of Whirlpool Corporation VEA-0017 - In the Matter of Whirlpool Corporation Sub-Zero Freezer Co. (Sub-Zero), GE Appliances (GE), and Whirlpool Corporation (Whirlpool) filed appeals of our November 3, 2000 decision, granting Viking Range Corporation (Viking) a six-month exception from the 2001 energy appliance efficiency standards for built-in refrigerators. Viking Range Corp., 28 DOE ¶ 81,002 (2000). As discussed below, we have granted the appeals in part. As a result, the six-month exception will be limited to 475 refrigerators per month and will be subject to a monthly reporting requirement. vea0015-16-17.pdf More Documents & Publications VEH-0015 - In the Matter of Sub-Zero Freezer Co. VEA-0015 - In the Matter of Sub-Zero Freezer Co.

48

On the minimum dark matter mass testable by neutrinos from the Sun  

SciTech Connect (OSTI)

We discuss a limitation on extracting bounds on the scattering cross section of dark matter with nucleons, using neutrinos from the Sun. If the dark matter particle is sufficiently light (less than about 4 GeV), the effect of evaporation is not negligible and the capture process goes in equilibrium with the evaporation. In this regime, the flux of solar neutrinos of dark matter origin becomes independent of the scattering cross section and therefore no constraint can be placed on it. We find the minimum values of dark matter masses for which the scattering cross section on nucleons can be probed using neutrinos from the Sun. We also provide simple and accurate fitting functions for all the relevant processes of GeV-scale dark matter in the Sun.

Busoni, Giorgio; Simone, Andrea De; Huang, Wei-Chih, E-mail: giorgio.busoni@sissa.it, E-mail: andrea.desimone@sissa.it, E-mail: wei-chih.huang@sissa.it [SISSA and INFN, Sezione di Trieste, via Bonomea 265, I-34136 Trieste (Italy)

2013-07-01T23:59:59.000Z

49

Limit on Neutrinoless ?? Decay of Xe-136 from the First Phase of KamLAND-Zen and Comparison with the Positive Claim in Ge-76  

E-Print Network [OSTI]

We present results from the first phase of the KamLAND-Zen double-beta decay experiment, corresponding to an exposure of 89.5 kg yr of Xe-136. We obtain a lower limit for the neutrinoless double-beta decay half-life of T_{1/2}^{0{\

KamLAND-Zen Collaboration

2012-11-16T23:59:59.000Z

50

Neutrinos from dark matter annihilations at the galactic center  

Science Journals Connector (OSTI)

We discuss the prospects for detection of high energy neutrinos from dark matter (DM) annihilation at the galactic center (GC). Despite the large uncertainties associated with our poor knowledge of the distribution of dark matter in the innermost regions of the Galaxy, we determine an upper limit on the neutrino flux by requiring that the associated gamma-ray emission does not exceed the observed flux. We conclude that a neutrino flux from the GC will not be observable by Antares if dark matter is made of neutralinos with mass smaller than 650GeV, while for heavier neutralinos, corresponding to models that will soon be probed by HESS (high energy stereoscopic system), the upper limit on the neutrino flux is barely above the Antares sensitivity. The detection of a larger flux would either require an alternative explanation, in terms of astrophysical processes, or the adoption of other dark matter candidates, disfavouring the case for neutralinos.

Gianfranco Bertone; Emmanuel Nezri; Jean Orloff; Joseph Silk

2004-09-02T23:59:59.000Z

51

Consideration of gravitational time delay and limitation of equivalence principle of inert and gravitational masses erases the problem of dark matter  

E-Print Network [OSTI]

The work is based on the equation of relativistic dynamics, the law of mass conservation of material body moving in gravitational field and the influence of gravitation on time passage discovered by Einstein. The formulae describing changes of inert and gravitational masses of material body were found. A new formula for the power of gravitational interaction of material bodies was derived. Newtons formula was shown to be the approximation of the new formula. It was determined that the equivalence principle of inert and gravitational masses is not universal. This principle is true with definite accuracy within the Solar system, when the sum of kinetic and potential energies of a material body is equal to zero. Limitation of the equivalence principle of inert and gravitational masses for galactic star systems erases the problem of dark matter.

Mikhail A. Samokhvalov

2014-04-01T23:59:59.000Z

52

Understanding of interface structures and reaction mechanisms induced by Ge or GeO diffusion in Al{sub 2}O{sub 3}/Ge structure  

SciTech Connect (OSTI)

The reaction mechanisms at Al{sub 2}O{sub 3}/Ge interfaces with thermal oxidation through the Al{sub 2}O{sub 3} layer have been investigated. X-ray photoelectron spectroscopy reveals that an Al{sub 6}Ge{sub 2}O{sub 13} layer is formed near the interface, and a GeO{sub 2} layer is formed on the Al{sub 2}O{sub 3} surface, suggesting Ge or GeO diffusion from the Ge surface. It is also clarified that the Al{sub 6}Ge{sub 2}O{sub 13} layer is formed by the different mechanism with a small activation energy of 0.2 eV, compared with the GeO{sub 2} formation limited by oxygen diffusion. Formation of Al-O-Ge bonds due to the AlGeO formation could lead appropriate interface structures with high interface qualities.

Shibayama, Shigehisa [Department of Crystalline Materials Science, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan) [Department of Crystalline Materials Science, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); JSPS, 5-3-1 Kojimachi, Chiyoda-ku, Tokyo 102-0083 (Japan); Kato, Kimihiko; Sakashita, Mitsuo; Takeuchi, Wakana; Taoka, Noriyuki; Nakatsuka, Osamu; Zaima, Shigeaki [Department of Crystalline Materials Science, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)] [Department of Crystalline Materials Science, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)

2013-08-19T23:59:59.000Z

53

Missing energy signatures of dark matter at the LHC  

Science Journals Connector (OSTI)

We use ATLAS and CMS searches in the monojet + missing energy and monophoton + missing energy final state to set limits on the couplings of dark matter to quarks and gluons. Working in an effective field theory framework we compare several existing monojet analyses and find that searches with high pT cuts are more sensitive to dark matter. We constrain the suppression scale of the effective dark matterstandard model interactions and convert these limits into bounds on the cross sections relevant to direct and indirect detection. We find that, for certain types of operators, in particular, spin-independent dark mattergluon couplings and spin-dependent dark matterquark couplings, LHC constraints from the monojet channel are competitive with, or superior to, limits from direct searches up to dark matter masses of order 1TeV. Comparing to indirect searches, we exclude, at 90%C.L., dark matter annihilating to quarks with the annihilation cross section of a thermal relic for masses below ?1570??GeV, depending on the Lorentz structure of the effective couplings. Monophoton limits are somewhat weaker than monojet bounds but still provide an important cross check in the case of a discovery in monojets. We also discuss the possibility that dark matterstandard model interactions at LHC energies cannot be described by effective operators, in which case we find that constraints can become either significantly stronger, or considerably weaker, depending on the mass and width of the intermediate particle. Further, we discuss the special case of dark matter coupling to the Higgs boson, and we show that searches for invisible Higgs decays would provide superior sensitivity, particularly for a light Higgs mass and light dark matter.

Patrick J. Fox; Roni Harnik; Joachim Kopp; Yuhsin Tsai

2012-03-30T23:59:59.000Z

54

Missing Energy Signatures of Dark Matter at the LHC  

E-Print Network [OSTI]

We use ATLAS and CMS searches in the mono-jet + missing energy and mono-photon + missing energy final state to set limits on the couplings of dark matter to quarks and gluons. Working in an effective field theory framework we compare several existing mono-jet analyses and find that searches with high p_T cuts are more sensitive to dark matter. We constrain the suppression scale of the effective dark matter-Standard Model interactions, and convert these limits into bounds on the cross sections relevant to direct and indirect detection. We find that, for certain types of operators, in particular spin-independent dark matter-gluon couplings and spin-dependent dark matter-quark couplings, LHC constraints from the mono-jet channel are competitive with, or superior to, limits from direct searches up to dark matter masses of order 1 TeV. Comparing to indirect searches, we exclude, at 90% C.L., dark matter annihilating to quarks with the annihilation cross section of a thermal relic for masses below ~ 15-70 GeV, depending on the Lorentz structure of the effective couplings. Mono-photon limits are somewhat weaker than mono-jet bounds, but still provide an important cross check in the case of a discovery in mono-jets. We also discuss the possibility that dark matter--Standard Model interactions at LHC energies cannot be described by effective operators, in which case we find that constraints can become either significantly stronger, or considerably weaker, depending on the mass and width of the intermediate particle. We also discuss the special case of dark matter coupling to the Higgs boson, and we show that searches for invisible Higgs decays would provide superior sensitivity, particularly for a light Higgs mass and light dark matter.

Patrick J. Fox; Roni Harnik; Joachim Kopp; Yuhsin Tsai

2011-09-20T23:59:59.000Z

55

Direct and indirect detection of dissipative dark matter  

E-Print Network [OSTI]

We study the constraints from direct detection and solar capture on dark matter scenarios with a subdominant dissipative component. This dissipative dark matter component in general has both a symmetric and asymmetric relic abundance. Dissipative dynamics allow this subdominant dark matter component to cool, resulting in its partial or total collapse into a smaller volume inside the halo (e.g., a dark disk) as well as a reduced thermal velocity dispersion compared to that of normal cold dark matter. We first show that these features considerably relax the limits from direct detection experiments on the couplings between standard model (SM) particles and dissipative dark matter. On the other hand, indirect detection of the annihilation of the symmetric dissipative dark matter component inside the Sun sets stringent and robust constraints on the properties of the dissipative dark matter. In particular, IceCube observations force dissipative dark matter particles with mass above 50 GeV to either have a small coupling to the SM or a low local density in the solar system, or to have a nearly asymmetric relic abundance. Possible helioseismology signals associated with purely asymmetric dissipative dark matter are discussed, with no present constraints.

JiJi Fan; Andrey Katz; Jessie Shelton

2013-12-04T23:59:59.000Z

56

Building | GE Global Research  

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

Scientists at GE Global Research get into the holiday spirit by bringing high-tech additive manufacturing techniques to Christmas... Read More Global Research and GE...

57

Search for Dark Matter Annihilations in the Sun with the 79-String IceCube Detector  

Science Journals Connector (OSTI)

We have performed a search for muon neutrinos from dark matter annihilation in the center of the Sun with the 79-string configuration of the IceCube neutrino telescope. For the first time, the DeepCore subarray is included in the analysis, lowering the energy threshold and extending the search to the austral summer. The 317days of data collected between June 2010 and May 2011 are consistent with the expected background from atmospheric muons and neutrinos. Upper limits are set on the dark matter annihilation rate, with conversions to limits on spin-dependent and spin-independent scattering cross sections of weakly interacting massive particles (WIMPs) on protons, for WIMP masses in the range 205000??GeV/c2. These are the most stringent spin-dependent WIMP-proton cross section limits to date above 35??GeV/c2 for most WIMP models.

M. G. Aartsen et al. (IceCube Collaboration)

2013-03-28T23:59:59.000Z

58

GE Research and Development | GE Global Research  

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

a decade of innovation Closing the Culture Gap Between Academia and Industry Additive Manufacturing Demonstration at GE Global Research innovate Latest News U.S....

59

Dark matter at colliders  

SciTech Connect (OSTI)

We show that colliders can impose strong constraints on dark matter. We take an effective field theory approach where dark matter couples to quarks and gluons through high dimensional operators. We discuss limits on interactions of dark matter and hadronic matter from the ATLAS experiment at the Large Hadron Collider (LHC). For spin-independent scattering, the LHC limits are stronger than those from direct detection experiments for light WIMPs. For spin-dependent scattering, the LHC sets better limits over much of parameter space.

Yu Haibo [Department of Physics, University of Michigan, Ann Arbor, MI, 48109 (United States)

2013-05-23T23:59:59.000Z

60

Working at GE Global Research | GE Global Research  

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

> Why GE Why GE Fostering curiosity and work that makes a big impact on the world. That's how GE helps keep talented researchers motivated. Inspire For our scientists,...

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


61

6.3.2 Ge spinels and substituted Ge spinels  

Science Journals Connector (OSTI)

Al-Ge-Li-O: LiGeAlO4 (Sp). Co-Ga-Ge-O: Co1+xGa2-2xGexO4 (Sp). Co-Ge-L-Li-O: Co0.5LiGeL5O4 (Sp). Co-Ge-Mg-O: Co2-xMgxGeO4 (Sp). Co-Ge-Ni-O: CoNiGeO4 (Sp). Co-Ge-O-Zn: Co2-xZnxGeO4 (Sp). Co-Ge-O: C...

D. Bonnenberg; H.P.J. Wijn

1970-01-01T23:59:59.000Z

62

12 GeV Upgrade | Jefferson Lab  

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

Science Science A Schematic of the 12 GeV Upgrade The 12 GeV Upgrade will greatly expand the research capabilities of Jefferson Lab, adding a fourth experimental hall, upgrading existing halls and doubling the power of the lab's accelerator. A D D I T I O N A L L I N K S: 12 GeV Home Public Interest Scientific Opportunities Hall D Status Updates Contacts Three-Year Accelerator Schedule 2014 - 2016 top-right bottom-left-corner bottom-right-corner 12 GeV Upgrade Physicists at Jefferson Lab are trying to find answers to some of nature's most perplexing questions about the universe by exploring the nucleus of the atom. Their goal is to answer such questions as: "What is the universe made of?" and "What holds everyday matter together?" In their search for answers, physicists smash electrons into atoms using

63

Chevron, GE form Technology Alliance  

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

Chevron, GE form Technology Alliance Chevron, GE form Technology Alliance The Chevron GE Technology Alliance will develop and commercialize valuable technologies to solve critical...

64

Searching for Dark Matter Annihilation in the Smith High-Velocity Cloud  

E-Print Network [OSTI]

Recent observations suggest that some high-velocity clouds may be confined by massive dark matter halos. In particular, the proximity and proposed dark matter content of the Smith Cloud make it a tempting target for the indirect detection of dark matter annihilation. We argue that the Smith Cloud may be a better target than some Milky Way dwarf spheroidal satellite galaxies and use gamma-ray observations from the Fermi Large Area Telescope to search for a dark matter annihilation signal. No significant gamma-ray excess is found coincident with the Smith Cloud, and we set strong limits on the dark matter annihilation cross section assuming a spatially-extended dark matter profile consistent with dynamical modeling of the Smith Cloud. Notably, these limits exclude the canonical thermal relic cross section ($\\sim 3\\times10^{-26}{\\rm cm}^{3}{\\rm s}^{-1}$) for dark matter masses $\\lesssim 30$ GeV annihilating via the $b \\bar b$ or $\\tau^{+}\\tau^{-}$ channels for certain assumptions of the dark matter density profile; however, uncertainties in the dark matter content of the Smith Cloud may significantly weaken these constraints.

Alex Drlica-Wagner; German A. Gomez-Vargas; John W. Hewitt; Tim Linden; Luigi Tibaldo

2014-06-30T23:59:59.000Z

65

Curing | GE Global Research  

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

this paper-based instrument, the size of a deck of playing cards, enables... Read More Additive Manufacturing Demonstration at GE Global Research See how GE Global Research is...

66

GE Global Research  

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

geglobalresearch.com Fri, 30 Jan 2015 17:46:29 +0000 en-US hourly 1 GE Researcher: Putting GE Beliefs into Action http:www.geglobalresearch.comblogcutting-edge-technology-peopl...

67

GE Healthcare Antibody Purification  

E-Print Network [OSTI]

.....................................................................................................................4 Chapter 3. Small-scale purification by affinity chromatography......................43 GeneralGE Healthcare Antibody Purification Handbook GE Healthcare imagination at work agination at work Purification Handbook Principles and Methods 18-1142-75 Isolation of mononuclear cells Methodology

Lebendiker, Mario

68

A Search for dark matter in events with one jet and missing transverse energy in $p\\bar{p}$ collisions at $\\sqrt{s} = 1.96$ TeV  

SciTech Connect (OSTI)

We present the results of a search for dark matter production in the monojet signature. We analyze a sample of Tevatron pp collisions at {radical}s = 1.96 TeV corresponding to an integrated luminosity of 6.7 fb{sup -1} recorded by the CDF II detector. In events with large missing transverse energy and one energetic jet, we find good agreement between the standard model prediction and the observed data. We set 90% confidence level upper limits on the dark matter production rate. The limits are translated into bounds on nucleon-dark matter scattering rates which are competitive with current direct detection bounds on spin-independent interaction below a dark matter candidate mass of 5 GeV/c{sup 2}, and on spin-dependent interactions up to masses of 200 GeV/c{sup 2}.

Aaltonen, T.; /Helsinki Inst. of Phys.; Alvarez Gonzalez, B.; /Oviedo U. /Cantabria Inst. of Phys.; Amerio, S.; /INFN, Padua; Amidei, D.; /Michigan U.; Anastassov, A.; /Northwestern U. /Fermilab; Annovi, A.; /Frascati; Antos, J.; /Comenius U.; Apollinari, G.; /Fermilab; Appel, J.A.; /Fermilab; Arisawa, T.; /Waseda U.; Artikov, A.; /Dubna, JINR /Texas A-M

2012-03-01T23:59:59.000Z

69

GE and Quirky | GE Global Research  

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

a partnership that introduces a whole new way of inventing. We teamed up with Quirky, the social product development company, to give everyday inventors access to GE's patents to...

70

Elimination of GeO(2) And Ge(3)N(4) Interfacial Transition Regions And Defects at N-Type Ge Interfaces: a Pathway for Formation of N-MOS Devices on Ge Substrates  

SciTech Connect (OSTI)

The contribution from relatively low-K SiON interfacial transition regions (ITRs) between Si and transition metal (TM) gate dielectrics places a significant limitation on equivalent oxide thickness (EOT) scaling for Si complementary metal-oxide-semiconductor (CMOS) devices. This limitation is equally significant and limiting for Ge CMOS devices. Low-K Ge-based ITRs in Ge devices have also been shown to limit performance and reliability, particular for n-MOS field effect transistors. This article identifies the source of significant electron trapping at interfaces between n-Ge or inverted p-Ge, and Ge oxide, nitride and oxynitride ITRs. This is shown to be an interfacial band alignment issue in which native Ge ITRs have conduction band offset energies smaller than those of TM dielectrics, and trap electrons for negative Ge substrate bias. This article also describes a novel remote plasma processing approach for effectively eliminating any significant native Ge ITRs and using a plasma-processing/annealing process sequence for bonding TM gate dielectrics directly to the Ge substrate surface.

Lucovsky, G.; Lee, S.; Long, J.P.; Seo, H.; Luning, J.

2009-05-19T23:59:59.000Z

71

Limited Lawn & Limited Commercial  

E-Print Network [OSTI]

Limited Lawn & Ornamental Limited Commercial Landscape Maintenance Review and Exams Limited for Commercial Landscape Maintenance Application: http://www.flaes.org/ pdf/lndspckt.pdf Limited Certification.floridatermitehelp.org or request by phone at 850-921-4177. Limited Lawn & Ornamental/Limited Commercial Landscape Maintenance

Watson, Craig A.

72

Limited Lawn & Limited Commercial  

E-Print Network [OSTI]

Limited Lawn & Ornamental Limited Commercial Landscape Maintenance Review and Exams Limited-921-4177. Limited Lawn & Ornamental/Limited Commercial Landscape Maintenance: Ornamental and Turf Pest Control (SM 7&O/Structural only). See web locations below for applications. Limited Certification for Commercial Landscape

Jawitz, James W.

73

Powering | GE Global Research  

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

Trials GE Global Research is advancing technology that will make the inspection of wind turbines faster and more reliable for customers.... Read More Brilliant(tm) Wind...

74

Predix | GE Global Research  

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

developed over the last three years and was first announced publicly at GE's Minds+Machines conference in Chicago, Illinois, in October 2013. Predix enables asset and operations...

75

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

E-Print Network [OSTI]

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

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

2014-11-28T23:59:59.000Z

76

Multiyear search for dark matter annihilations in the Sun with the AMANDA-II and IceCube detectors  

Science Journals Connector (OSTI)

A search for an excess of muon neutrinos from dark matter annihilations in the Sun has been performed with the AMANDA-II neutrino telescope using data collected in 812 days of live time between 2001 and 2006 and 149 days of live time collected with the AMANDA-II and the 40-string configuration of IceCube during 2008 and early 2009. No excess over the expected atmospheric neutrino background has been observed. We combine these results with the previously published IceCube limits obtained with data taken during 2007 to obtain a total live time of 1065 days. We provide an upper limit at 90% confidence level on the annihilation rate of captured neutralinos in the Sun, as well as the corresponding muon flux limit at the Earth, both as functions of the neutralino mass in the range 505000GeV. We also derive a limit on the neutralino-proton spin-dependent and spin-independent cross section. The limits presented here improve the previous results obtained by the collaboration between a factor of 2 and 5, as well as extending the neutralino masses probed down to 50GeV. The spin-dependent cross section limits are the most stringent so far for neutralino masses above 200GeV, and well below direct search results in the mass range from 50GeV to 5TeV.

R. Abbasi et al. (IceCube Collaboration)

2012-02-22T23:59:59.000Z

77

GE, Sandia National Lab Improve Wind Turbines | GE Global Research  

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

GE, Sandia National Lab Discover Pathway to Quieter, More Productive Wind Turbines GE, Sandia National Lab Discover Pathway to Quieter, More Productive Wind Turbines Use of...

78

The Sensitivity of HAWC to High-Mass Dark Matter Annihilations  

E-Print Network [OSTI]

The High Altitude Water Cherenkov (HAWC) observatory is a wide field-of-view detector sensitive to gamma rays of 100 GeV to a few hundred TeV. Located in central Mexico at 19 degrees North latitude and 4100 m above sea level, HAWC will observe gamma rays and cosmic rays with an array of water Cherenkov detectors. The full HAWC array is scheduled to be operational in Spring 2015. In this paper, we study the HAWC sensitivity to the gamma-ray signatures of high-mass (multi- TeV) dark matter annihilation. The HAWC observatory will be sensitive to diverse searches for dark matter annihilation, including annihilation from extended dark matter sources, the diffuse gamma-ray emission from dark matter annihilation, and gamma-ray emission from non-luminous dark matter subhalos. Here we consider the HAWC sensitivity to a subset of these sources, including dwarf galaxies, the M31 galaxy, the Virgo cluster, and the Galactic center. We simulate the HAWC response to gamma rays from these sources in several well-motivated dark matter annihilation channels. If no gamma-ray excess is observed, we show the limits HAWC can place on the dark matter cross-section from these sources. In particular, in the case of dark matter annihilation into gauge bosons, HAWC will be able to detect a narrow range of dark matter masses to cross-sections below thermal. HAWC should also be sensitive to non-thermal cross-sections for masses up to nearly 1000 TeV. The constraints placed by HAWC on the dark matter cross-section from known sources should be competitive with current limits in the mass range where HAWC has similar sensitivity. HAWC can additionally explore higher dark matter masses than are currently constrained.

A. U. Abeysekara; R. Alfaro; C. Alvarez; J. D. Alvarez; R. Arceo; J. C. Arteaga-Velazquez; H. A. Ayala Solares; A. S. Barber; B. M. Baughman; N. Bautista-Elivar; J. Becerra Gonzalez; E. Belmont; S. Y. BenZvi; D. Berley; M. Bonilla Rosales; J. Braun; R. A. Caballero-Lopez; K. S. Caballero-Mora; A. Carraminana; M. Castillo; U. Cotti; J. Cotzomi; E. de la Fuente; C. De Leon; T. DeYoung; R. Diaz Hernandez; L. Diaz-Cruz; J. C. Diaz-Velez; B. L. Dingus; M. A. DuVernois; R. W. Ellsworth; S. F. E.; D. W. Fiorino; N. Fraija; A. Galindo; F. Garfias; M. M. Gonzalez; J. A. Goodman; V. Grabski; M. Gussert; Z. Hampel-Arias; J. P. Harding; C. M. Hui; P. Huentemeyer; A. Imran; A. Iriarte; P. Karn; D. Kieda; G. J. Kunde; A. Lara; R. J. Lauer; W. H. Lee; D. Lennarz; H. Leon Vargas; E. C. Linares; J. T. Linnemann; M. Longo; R. Luna-Garcia; A. Marinelli; H. Martinez; O. Martinez; J. Martinez-Castro; J. A. J. Matthews; J. McEnery; E. Mendoza Torres; P. Miranda-Romagnoli; E. Moreno; M. Mostafa; L. Nellen; M. Newbold; R. Noriega-Papaqui; T. Oceguera-Becerra; B. Patricelli; R. Pelayo; E. G. Perez-Perez; J. Pretz; C. Riviere; D. Rosa-Gonzalez; J. Ryan; H. Salazar; F. Salesa; A. Sandoval; M. Schneider; S. Silich; G. Sinnis; A. J. Smith; K. Sparks Woodle; R. W. Springer; I. Taboada; P. A. Toale; K. Tollefson; I. Torres; T. N. Ukwatta; L. Villasenor; T. Weisgarber; S. Westerhoff; I. G. Wisher; J. Wood; G. B. Yodh; P. W. Younk; D. Zaborov; A. Zepeda; H. Zhou; K. N. Abazajian

2014-12-09T23:59:59.000Z

79

Chevron, GE form Technology Alliance  

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

Chevron, GE form Technology Alliance February 3, 2014 HOUSTON, TX, Feb. 3, 2014-Chevron Energy Technology Company and GE Oil & Gas announced today the creation of the Chevron GE...

80

Carousolar | GE Global Research  

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

Fun Carousolar Uses Solar Power for Fun This amazing all-white carousel is powered by 100 solar panels and lit up by GE's colorful TETRA Countour LED lights. You Might Also Like...

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


81

Anapole dark matter at the LHC  

Science Journals Connector (OSTI)

The anapole moment is the only allowed electromagnetic moment for Majorana fermions. Fermionic dark matter acquiring an anapole can have a standard thermal history and be consistent with current direct detection experiments. In this paper, we calculate the collider monojet signatures of anapole dark matter and show that the current LHC results exclude anapole dark matter with mass less than 100GeV, for an anapole coupling that leads to the correct thermal relic abundance.

Yu Gao; Chiu Man Ho; Robert J. Scherrer

2014-02-12T23:59:59.000Z

82

IceCube search for dark matter annihilation in nearby galaxies and galaxy clusters  

Science Journals Connector (OSTI)

We present the results of a first search for self-annihilating dark matter in nearby galaxies and galaxy clusters using a sample of high-energy neutrinos acquired in 339.8days of live time during 2009/10 with the IceCube neutrino observatory in its 59-string configuration. The targets of interest include the Virgo and Coma galaxy clusters, the Andromeda galaxy, and several dwarf galaxies. We obtain upper limits on the cross section as a function of the weakly interacting massive particle mass between 300GeV and 100TeV for the annihilation into bb, W+W-, ?+?-, ?+?-, and ??. A limit derived for the Virgo cluster, when assuming a large effect from subhalos, challenges the weakly interacting massive particle interpretation of a recently observed GeV positron excess in cosmic rays.

M. G. Aartsen et al. (IceCube Collaboration)

2013-12-06T23:59:59.000Z

83

The Sensitivity of HAWC to High-Mass Dark Matter Annihilations  

E-Print Network [OSTI]

The High Altitude Water Cherenkov (HAWC) observatory is a wide field-of-view detector sensitive to gamma rays of 100 GeV to a few hundred TeV. Located in central Mexico at 19 degrees North latitude and 4100 m above sea level, HAWC will observe gamma rays and cosmic rays with an array of water Cherenkov detectors. The full HAWC array is scheduled to be operational in Summer 2014. In this paper, we study the HAWC sensitivity to the gamma-ray signatures of high-mass (multi-TeV) dark matter annihilation. The HAWC observatory will be sensitive to diverse searches for dark matter annihilation, including annihilation from extended dark matter sources, the diffuse gamma-ray emission from dark matter annihilation, and gamma-ray emission from non-luminous dark matter subhalos. Here we consider the HAWC sensitivity to a subset of these sources, including dwarf galaxies, the M31 galaxy, the Virgo cluster, and the Galactic center. We simulate the HAWC response to gamma rays from these sources in several well-motivated dark matter annihilation channels. If no gamma-ray excess is observed, we show the limits HAWC can place on the dark matter cross-section from these sources. In particular, in the case of dark matter annihilation into gauge bosons, HAWC will be able to detect a narrow range of dark matter masses to cross-sections below thermal. HAWC should also be sensitive to non-thermal cross-sections for masses up to nearly 1000 TeV. The constraints placed by HAWC on the dark matter cross-section from known sources should be competitive with current limits.

A. U. Abeysekara; R. Alfaro; C. Alvarez; J. D. lvarez; R. Arceo; J. C. Arteaga-Velzquez; H. A. Ayala Solares; A. S. Barber; B. M. Baughman; N. Bautista-Elivar; J. Becerra Gonzalez; E. Belmont; S. Y. BenZvi; D. Berley; M. Bonilla Rosales; J. Braun; R. A. Caballero-Lopez; K. S. Caballero-Mora; A. Carramiana; M. Castillo; U. Cotti; J. Cotzomi; E. de la Fuente; C. De Len; T. DeYoung; R. Diaz Hernandez; L. Diaz-Cruz; J. C. D\\'\\iaz-Vlez; B. L. Dingus; M. A. DuVernois; R. W. Ellsworth; S. F. E.; D. W. Fiorino; N. Fraija; A. Galindo; F. Garfias; M. M. Gonzlez; J. A. Goodman; V. Grabski; M. Gussert; Z. Hampel-Arias; J. P. Harding; C. M. Hui; P. Hntemeyer; A. Imran; A. Iriarte; P. Karn; D. Kieda; G. J. Kunde; A. Lara; R. J. Lauer; W. H. Lee; D. Lennarz; H. Len Vargas; E. C. Linares; J. T. Linnemann; M. Longo; R. Luna-Garcia; A. Marinelli; H. Martinez; O. Martinez; J. Mart\\'\\inez-Castro; J. A. J. Matthews; J. McEnery; E. Mendoza Torres; P. Miranda-Romagnoli; E. Moreno; M. Mostaf; L. Nellen; M. Newbold; R. Noriega-Papaqui; T. Oceguera-Becerra; B. Patricelli; R. Pelayo; E. G. Prez-Prez; J. Pretz; C. Rivire; D. Rosa-Gonzlez; J. Ryan; H. Salazar; F. Salesa; A. Sandoval; M. Schneider; S. Silich; G. Sinnis; A. J. Smith; K. Sparks Woodle; R. W. Springer; I. Taboada; P. A. Toale; K. Tollefson; I. Torres; T. N. Ukwatta; L. Villaseor; T. Weisgarber; S. Westerhoff; I. G. Wisher; J. Wood; G. B. Yodh; P. W. Younk; D. Zaborov; A. Zepeda; H. Zhou; K. N. Abazajian

2014-05-07T23:59:59.000Z

84

Results from the Cryogenic Dark Matter Search experiment  

E-Print Network [OSTI]

The Cryogenic Dark Matter Search experiment uses low-temperature solid-state detectors to seek Weakly Interacting Massive Particles (WIMPs) and has the world's best exclusion limit on the spin-independent WIMP-nucleon cross section. The experiment uses ionization and athermal phonon signals from particle interactions to discriminate between candidate (nuclear recoil) and background (electron recoil) events with extremely high efficiency. The detectors' low energy threshold for electron recoil events allows us to perform the search for relic axions and solar axions which can interact in the detector via the axio-electric coupling $g_{a\\bar{e}e}$ and the Primakoff coupling $g_{a\\gamma\\gamma}$ respectively. We describe the experiment and our most recent results from the Soudan 5-tower data runs which include a world-leading upper limit on the WIMP-nucleon spin-independent cross section with a minimum of $4.6\\times10^{-44}$ cm$^{2}$ at the 90% confidence level (CL) for a 60 GeV/c$^{2}$ WIMP, the world-leading experimental upper limit on the axio-electric coupling of $1.4\\times10^{-12}$ at the 90% CL for a 2.5 keV/c$^{2}$ axion, and the upper limit on the axion-photon coupling of $2.4\\times10^{-9}$ GeV$^{-1}$ at the 95% CL.

Oleg Kamaev; for the CDMS Collaboration

2009-10-15T23:59:59.000Z

85

When matter matters  

SciTech Connect (OSTI)

We study a recently proposed scenario for the early universe:Subluminal Galilean Genesis. We prove that without any other matter present in the spatially flat Friedmann universe, the perturbations of the Galileon scalar field propagate with a speed at most equal to the speed of light. This proof applies to all cosmological solutions to the whole phase space. However, in a more realistic situation, when one includes any matter which is not directly coupled to the Galileon, there always exists a region of phase space where these perturbations propagate superluminally, indeed with arbitrarily high speed. We illustrate our analytic proof with numerical computations. We discuss the implications of this result for the possible UV completion of the model.

Easson, Damien A. [Department of Physics and School of Earth and Space Exploration and Beyond Center, Arizona State University, Tempe, AZ, 85287-1504 (United States); Sawicki, Ignacy [Institut fr Theoretische Physik, Ruprecht-Karls-Universitt Heidelberg Philosophenweg 16, 69120 Heidelberg (Germany); Vikman, Alexander, E-mail: easson@asu.edu, E-mail: ignacy.sawicki@uni-heidelberg.de, E-mail: alexander.vikman@cern.ch [CERN, Theory Division, CH-1211 Genve 23 (Switzerland)

2013-07-01T23:59:59.000Z

86

Environmentally Selected WIMP Dark Matter with High-Scale Supersymmetry Breaking  

E-Print Network [OSTI]

We explore the possibility that both the weak scale and the thermal relic dark matter abundance are environmentally selected in a multiverse. An underlying supersymmetric theory containing the states of the MSSM and singlets, with supersymmetry and R symmetry broken at unified scales, has just two realistic low energy effective theories. One theory, (SM + \\tilde{w}), is the Standard Model augmented only by the wino, having a mass near 3 TeV, and has a Higgs boson mass in the range of (127 - 142) GeV. The other theory, (SM + \\tilde{h}/\\tilde{s}), has Higgsinos and a singlino added to the Standard Model. The Higgs boson mass depends on the single new Yukawa coupling of the theory, y, and is near 141 GeV for small y but grows to be as large as 210 GeV as this new coupling approaches strong coupling at high energies. Much of the parameter space of this theory will be probed by direct detection searches for dark matter that push two orders of magnitude below the present bounds; furthermore, the dark matter mass and cross section on nucleons are correlated with the Higgs boson mass. The indirect detection signal of monochromatic photons from the galactic center is computed, and the range of parameters that may be accessible to LHC searches for trilepton events is explored. Taking a broader view, allowing the possibility of R symmetry protection to the TeV scale or axion dark matter, we find four more theories: (SM + axion), two versions of Split Supersymmetry, and the E-MSSM, where a little supersymmetric hierarchy is predicted. The special Higgs mass value of (141 \\pm 2) GeV appears in symmetry limits of three of the six theories, (SM + axion), (SM + \\tilde{w}) and (SM + \\tilde{h}/\\tilde{s}), motivating a comparison of other signals of these three theories.

Gilly Elor; Hock-Seng Goh; Lawrence J. Hall; Piyush Kumar; Yasunori Nomura

2009-12-19T23:59:59.000Z

87

Is the 130 GeV line real? A search for systematics in the Fermi-LAT data  

SciTech Connect (OSTI)

Our recent claims of a Galactic center feature in Fermi-LAT data at approximately 130 GeV have motivated a large number of papers proposing explanations ranging from dark matter annihilation to monoenergetic pulsar winds. Because of the importance of such interpretations for physics and astrophysics, a discovery will require not only additional data, but a thorough investigation of possible LAT systematics. While we do not have access to the details of each event reconstruction, we do have information about each event from the public event lists and spacecraft parameter files. These data allow us to search for suspicious trends that could indicate a spurious signal. We consider several hypotheses that might make an instrumental artifact more apparent at the Galactic center, and find them implausible. We also search for an instrumental signature in the Earth limb photons, which provide a smooth reference spectrum for null tests. We find no significant 130 GeV feature in the Earth limb sample. However, we do find a marginally significant 130 GeV feature in Earth limb photons with a limited range of detector incidence angles. This raises concerns about the 130 GeV Galactic center feature, even though we can think of no plausible model of instrumental behavior that connects the two. A modest amount of additional limb data would tell us if the limb feature is a statistical fluke. If the limb feature persists, it would raise doubts about the Pass 7 processing of E > 100 GeV events. At present we find no instrumental systematics that could plausibly explain the excess Galactic center emission at 130 GeV.

Finkbeiner, Douglas P.; Su, Meng [Institute for Theory and Computation, Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS-51, Cambridge, MA 02138 (United States); Weniger, Christoph, E-mail: dfinkbeiner@cfa.harvard.edu, E-mail: mengsu@cfa.harvard.edu, E-mail: weniger@mpp.mpg.de [Max-Planck-Institut fr Physik, Fhringer Ring 6, 80805 Mnchen (Germany)

2013-01-01T23:59:59.000Z

88

CONSTRAINTS ON DARK MATTER ANNIHILATION IN CLUSTERS OF GALAXIES FROM DIFFUSE RADIO EMISSION  

SciTech Connect (OSTI)

Annihilation of dark matter can result in the production of stable Standard Model particles including electrons and positrons that, in the presence of magnetic fields, lose energy via synchrotron radiation, observable as radio emission. Galaxy clusters are excellent targets to search for or to constrain the rate of dark matter annihilation, as they are both massive and dark matter dominated. In this study, we place limits on dark matter annihilation in a sample of nearby clusters using upper limits on the diffuse radio emission, low levels of observed diffuse emission, or detections of radio mini-halos. We find that the strongest limits on the annihilation cross section are better than limits derived from the non-detection of clusters in the gamma-ray band by a factor of {approx}3 or more when the same annihilation channel and substructure model, but different best-case clusters, are compared. The limits on the cross section depend on the assumed amount of substructure, varying by as much as two orders of magnitude for increasingly optimistic substructure models as compared to a smooth Navarro-Frenk-White profile. In our most optimistic case, using the results of the Phoenix Project, we find that the derived limits reach below the thermal relic cross section of 3 Multiplication-Sign 10{sup -26} cm{sup 3} s{sup -1} for dark matter masses as large as 400 GeV, for the b b-bar annihilation channel. We discuss uncertainties due to the limited available data on the magnetic field structure of individual clusters. We also report the discovery of diffuse radio emission from the central 30-40 kpc regions of the groups M49 and NGC 4636.

Storm, Emma; Jeltema, Tesla E.; Profumo, Stefano [Department of Physics, University of California, 1156 High St., Santa Cruz, CA 95064 (United States); Rudnick, Lawrence [Minnesota Institute for Astrophysics, School of Physics and Astronomy, University of Minnesota, 116 Church Street SE, Minneapolis, MN 55455 (United States)

2013-05-10T23:59:59.000Z

89

Ge-Au eutectic bonding of Ge {100} single crystals  

Science Journals Connector (OSTI)

We present preliminary results on the eutectic bonding between two {100} Ge single crystal surfaces using thin films of ... Au sample show epitaxial growth of Ge. In sections of the bond, lattice continuity...

W. B. Knowlton; K. M. Itoh; J. W. Beeman; J. H. Emes

1993-11-01T23:59:59.000Z

90

Axion cold dark matter: status after Planck and BICEP2  

E-Print Network [OSTI]

We investigate the axion dark matter scenario (ADM), in which axions account for all of the dark matter in the Universe, in light of the most recent cosmological data. In particular, we use the Planck temperature data, complemented by WMAP E-polarization measurements, as well as the recent BICEP2 observations of B-modes. Baryon Acoustic Oscillation data, including those from the Baryon Oscillation Spectroscopic Survey, are also considered in the numerical analyses. We find that, in the minimal ADM scenario, the full dataset implies that the axion mass m_a = 82.2 pm 1.1 {\\mu}eV (corresponding to the Peccei-Quinn symmetry being broken at a scale f_a = (7.54 pm 0.10)*10^10 GeV), or m_a = 76.6 pm 2.6 {\\mu}eV (f_a = (8.08 pm 0.27)*10^10 GeV) when we allow for a non- standard effective number of relativistic species Neff . We also find a 2{\\sigma} preference for Neff > 3.046. The limit on the sum of neutrino masses is Sum m_{\

E. Di Valentino; E. Giusarma; M. Lattanzi; A. Melchiorri; O. Mena

2014-05-08T23:59:59.000Z

91

Implications of Direct Dark Matter Constraints for Minimal Supersymmetric Standard Model Higgs Boson Searches at the Tevatron  

E-Print Network [OSTI]

Searches for the Minimal Supersymmetric Standard Model (MSSM) Higgs bosons are among the most promising channels for exploring new physics at the Tevatron. In particular, interesting regions of large $\\tan \\beta$ and small $m_A$ are probed by searches for heavy neutral Higgs bosons, A and H, when they decay to $\\tau^+ \\tau^-$ and $b\\bar{b}$. At the same time, direct searches for dark matter, such as CDMS, attempt to observe neutralino dark matter particles scattering elastically off nuclei. This can occur through t-channel Higgs exchange, which has a large cross section in the case of large $\\tan \\beta$ and small $m_A$. As a result, there is a natural interplay between the heavy, neutral Higgs searches at the Tevatron and the region of parameter space explored by CDMS. We show that if the lightest neutralino makes up the dark matter of our universe, current limits from CDMS strongly constrain the prospects of heavy, neutral MSSM Higgs discovery at the Tevatron (at 3 sigma with 4 fb^-1 per experiment) unless $|\\mu| \\gsim$ 400 GeV. The limits of CDMS projected for 2007 will increase this constraint to $|\\mu| \\gsim$ 800 GeV. On the other hand, if CDMS does observe neutralino dark matter in the near future, it will make the discovery of heavy, neutral MSSM Higgs bosons far more likely at the Tevatron.

Marcela Carena; Dan Hooper; Peter Skands

2006-08-22T23:59:59.000Z

92

Colon Cancer Mapping | GE Global Research  

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

Vanderbilt, GE Team Seek Deeper Understanding of Colon Cancer Vanderbilt, GE Team Seek Deeper Understanding of Colon Cancer Vanderbilt University has partnered with GE Global...

93

GE | OpenEI Community  

Open Energy Info (EERE)

by Jessi3bl(15) Member 16 December, 2012 - 19:18 GE, Clean Energy Fuels Partner to Expand Natural Gas Highway clean energy Clean Energy Fuels energy Environment Fuel GE Innovation...

94

Dark Matter Searches with GLAST  

E-Print Network [OSTI]

Indirect detection of particle dark matter relies upon pair annihilation of Weakly Interaction Massive Particles (WIMPs), which is complementary to the well known techniques of direct detection (WIMP-nucleus scattering) and collider production (WIMP pair production). Pair annihilation of WIMPs results in the production of gamma-rays, neutrinos, and anti-matter. Of the various experiments sensitive to indirect detection of dark matter, the Gamma-ray Large Area Space Telescope (GLAST) may play the most crucial role in the next few years. After launch in late 2007, The GLAST Large Area Telescope (LAT) will survey the gamma-ray sky in the energy range of 20MeV-300GeV. By eliminating charged particle background above 100 MeV, GLAST may be sensitive to as yet to be observed Milky Way dark matter subhalos, as well as WIMP pair annihilation spectral lines from the Milky Way halo. Discovery of gamma-ray signals from dark matter in the Milky Way would not only demonstrate the particle nature of dark matter; it would also open a new observational window on galactic dark matter substructure. Location of new dark matter sources by GLAST would dramatically alter the experimental landscape; ground based gamma ray telescopes could follow up on the new GLAST sources with precision measurements of the WIMP pair annihilation spectrum.

Lawrence Wai; GLAST LAT Collaboration

2007-01-31T23:59:59.000Z

95

On The Origin of Light Dark Matter Species  

SciTech Connect (OSTI)

TeV-mass dark matter charged under a new GeV-scale gauge force can explain electronic cosmic-ray anomalies. We propose that the CoGeNT and DAMA direct detection experiments are observing scattering of light stable states 'GeV-Matter' that are charged under this force and constitute a small fraction of the dark matter halo. Dark higgsinos in a supersymmetric dark sector are natural candidates for GeV-Matter that scatter off protons with a universal cross-section of 5 x 10{sup -38} cm{sup 2} and can naturally be split by 10-30 keV so that their dominant interaction with protons is down-scattering. As an example, down-scattering of an O(5) GeV dark higgsino can simultaneously explain the spectra observed by both CoGeNT and DAMA. The event rates in these experiments correspond to a GeV-Matter abundance of 0.2-1% of the halo mass density. This abundance can arise directly from thermal freeze-out at weak coupling, or from the late decay of an unstable TeV-scale WIMP. Our proposal can be tested by searches for exotics in the BaBar and Belle datasets.

Essig, Rouven; Kaplan, Jared; Schuster, Philip; /SLAC; Toro, Natalia; /Stanford U., Phys. Dept.

2010-06-04T23:59:59.000Z

96

(La0.3Ge0.7)(Ni0.85Ge0.15)2Ge2  

Science Journals Connector (OSTI)

It contains the standardized crystallographic data set of (La0.3Ge0.7)(Ni0.85Ge0.15)2Ge2 representing the structure type (La0.30Ge0.70)(Ni0.85Ge0.15)2Ge2.

P. Villars; K. Cenzual; J. Daams

2011-01-01T23:59:59.000Z

97

Constraining Dark Matter Models from a Combined Analysis of Milky Way Satellites with the Fermi Large Area Telescope  

SciTech Connect (OSTI)

Satellite galaxies of the Milky Way are among the most promising targets for dark matter searches in gamma rays. We present a search for dark matter consisting of weakly interacting massive particles, applying a joint likelihood analysis to 10 satellite galaxies with 24 months of data of the Fermi Large Area Telescope. No dark matter signal is detected. Including the uncertainty in the dark matter distribution, robust upper limits are placed on dark matter annihilation cross sections. The 95% confidence level upper limits range from about 10{sup -26} cm{sup 3} s{sup -1} at 5 GeV to about 5 x 10{sup -23} cm{sup 3} s{sup -1} at 1 TeV, depending on the dark matter annihilation final state. For the first time, using gamma rays, we are able to rule out models with the most generic cross section ({approx}3 x 10{sup -26} cm{sup 3} s{sup -1} for a purely s-wave cross section), without assuming additional boost factors.

Ackermann, M.; Ajello, M.; /Stanford U., HEPL /Taiwan, Natl. Taiwan U. /SLAC; Albert, A.; /Taiwan, Natl. Taiwan U. /Ohio State U.; Atwood, W.B.; /UC, Santa Cruz; Baldini, L.; /INFN, Pisa; Ballet, J.; /DAPNIA, Saclay; Barbiellini, G.; /INFN, Trieste /Trieste U.; Bastieri, D.; /INFN, Padua /Padua U.; Bechtol, K.; /Stanford U., HEPL /Taiwan, Natl. Taiwan U. /SLAC; Bellazzini, R.; /INFN, Pisa; Berenji, B.; Blandford, R.D.; Bloom, E.D.; /Stanford U., HEPL /Taiwan, Natl. Taiwan U. /SLAC; Bonamente, E.; /INFN, Perugia /Perugia U.; Borgland, A.W.; /Stanford U., HEPL /Taiwan, Natl. Taiwan U. /SLAC; Bregeon, J.; /INFN, Pisa; Brigida, M.; /Bari Polytechnic /INFN, Bari; Bruel, P.; /Ecole Polytechnique; Buehler, R.; /Stanford U., HEPL /Taiwan, Natl. Taiwan U. /SLAC; Burnett, T.H.; /Washington U., Seattle; Buson, S.; /INFN, Padua /Padua U. /ICE, Bellaterra /Stanford U., HEPL /Taiwan, Natl. Taiwan U. /SLAC /INFN, Rome /Rome U. /IASF, Milan /IASF, Milan /DAPNIA, Saclay /INFN, Perugia /Perugia U. /Stanford U., HEPL /Taiwan, Natl. Taiwan U. /SLAC /Artep Inc. /Stanford U., HEPL /Taiwan, Natl. Taiwan U. /SLAC /ASDC, Frascati /Perugia U. /Stanford U., HEPL /Taiwan, Natl. Taiwan U. /SLAC /Montpellier U. /Stockholm U. /Stockholm U., OKC /ASDC, Frascati /ASDC, Frascati /Udine U. /INFN, Trieste /Bari Polytechnic /INFN, Bari /Naval Research Lab, Wash., D.C. /Stanford U., HEPL /Taiwan, Natl. Taiwan U. /SLAC /Montpellier U. /Bari Polytechnic /INFN, Bari /Ecole Polytechnique /NASA, Goddard /Hiroshima U. /Stanford U., HEPL /Taiwan, Natl. Taiwan U. /SLAC /Bari Polytechnic /INFN, Bari /INFN, Bari /ASDC, Frascati /NASA, Goddard /INFN, Perugia /Perugia U. /Bari Polytechnic /INFN, Bari /Bologna Observ. /Stanford U., HEPL /Taiwan, Natl. Taiwan U. /SLAC /DAPNIA, Saclay /Alabama U., Huntsville; /more authors..

2012-09-14T23:59:59.000Z

98

D matter  

Science Journals Connector (OSTI)

We study the properties and phenomenology of particlelike states originating from D branes whose spatial dimensions are all compactified. They are nonperturbative states in string theory and we refer to them as D matter. In contrast to other nonperturbative objects such as t HooftPolyakov monopoles, D-matter states could have perturbative couplings among themselves and with ordinary matter. The lightest D particle (LDP) could be stable because it is the lightest state carrying certain (integer or discrete) quantum numbers. Depending on the string scale, they could be cold dark matter candidates with properties similar to that of WIMPs or wimpzillas. The spectrum of excited states of D matter exhibits an interesting pattern which could be distinguished from that of Kaluza-Klein modes, winding states, and string resonances. We speculate about possible signatures of D matter from ultrahigh energy cosmic rays and colliders.

Gary Shiu and Lian-Tao Wang

2004-06-29T23:59:59.000Z

99

Dark Matters  

ScienceCinema (OSTI)

One of the greatest mysteries in the cosmos is that it is mostly dark. Astronomers and particle physicists today are seeking to unravel the nature of this mysterious, but pervasive dark matter which has profoundly influenced the formation of structure in the universe. I will describe the complex interplay between galaxy formation and dark matter detectability and review recent attempts to measure particle dark matter by direct and indirect means.

Joseph Silk

2010-01-08T23:59:59.000Z

100

Dark matter  

Science Journals Connector (OSTI)

...just how much dark matter in baryons...have lead to the discovery that a large component of the dark mass in groups...the highest-energy photons and the...to that of the discovery of the microwave...experiments assume the dark matter in the...c) Vacuum energy and the cosmological...

1999-01-01T23:59:59.000Z

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


101

On the sbottom resonance in dark matter scattering  

SciTech Connect (OSTI)

A resonance in the neutralino-nucleus elastic scattering cross section is usually purported when the neutralino-sbottom mass difference m{sub b-tilde}?m{sub ?} is equal to the bottom quark mass m{sub b} ? 4 GeV. Such a scenario has been discussed as a viable model for light ( ? 10 GeV) neutralino dark matter as explanation of possible DAMA and CoGeNT direct detection signals. Here we give physical and analytical arguments showing that the sbottom resonance may actually not be there. In particular, we show analytically that the one-loop gluon-neutralino scattering amplitude has no pole at m{sub b-tilde} = m{sub ?}+m{sub b}, while by analytic continuation to the regime m{sub b-tilde} < m{sub ?}, it develops a pole at m{sub b-tilde} = m{sub ?}?m{sub b}. In the limit of vanishing gluon momenta, this pole corresponds to the only cut of the neutralino self-energy diagram with a quark and a squark running in the loop, when the decay process ?? Q-tilde +Q becomes kinematically allowed. The pole can be interpreted as the formation of a b-tilde b-bar qqq or b-tilde *bqqq resonant state (where qqq are the nucleon valence quarks), which is however kinematically not accessible if the neutralino is the LSP. Our analysis shows that the common practice of estimating the neutralino-nucleon cross section by introducing an ad-hoc pole at m{sub b-tilde} = m{sub ?}+m{sub b} into the effective four-fermion interaction (also including higher-twist effects) should be discouraged, since it corresponds to adding a spurious pole to the scattering process at the center-of-mass energy (s){sup 1/2} ? m{sub ?} ? m{sub b-tilde}?m{sub b}. Our considerations can be extended from the specific case of supersymmetry to other similar cases in which the dark matter particle scatters off nucleons through the exchange of a b-flavored state almost degenerate in mass with the dark matter particle, such as for instance in theories with extra dimensions and in other mass-degenerate dark matter scenarios recently discussed in the literature.

Gondolo, Paolo [Department of Physics and Astronomy, University of Utah, Salt Lake City, Utah 84112-0830 (United States); Scopel, Stefano, E-mail: paolo.gondolo@utah.edu, E-mail: scopel@sogang.ac.kr [Department of Physics, Sogang University, Seoul (Korea, Republic of)

2013-10-01T23:59:59.000Z

102

Structural and phonon transmission study of Ge-Au-Ge eutectically bonded interfaces  

SciTech Connect (OSTI)

This thesis presents a structural analysis and phonon transparency investigation of the Ge-Au-Ge eutectic bond interface. Interface development was intended to maximize the interfacial ballistic phonon transparency to enhance the detection of the dark matter candidate WIMPs. The process which was developed provides an interface which produces minimal stress, low amounts of impurities, and insures Ge lattice continuity through the interface. For initial Au thicknesses of greater than 1,000 {angstrom} Au per substrate side, eutectic epitaxial growth resulted in a Au dendritic structure with 95% cross sectional and 90% planar Au interfacial area coverages. In sections in which Ge bridged the interface, lattice continuity across the interface was apparent. Epitaxial solidification of the eutectic interface with initial Au thicknesses < 500 A per substrate side produced Au agglomerations thereby reducing the Au planar interfacial area coverage to as little as 30%. The mechanism for Au coalescence was attributed to lateral diffusion of Ge and Au in the liquid phase during solidification. Phonon transmission studies were performed on eutectic interfaces with initial Au thicknesses of 1,000 {angstrom}, 500 {angstrom}, and 300 {angstrom} per substrate side. Phonon imaging of eutectically bonded samples with initial Au thicknesses of 300 {angstrom}/side revealed reproducible interfacial percent phonon transmissions from 60% to 70%. Line scan phonon imaging verified the results. Phonon propagation TOF spectra distinctly showed the predominant phonon propagation mode was ballistic. This was substantiated by phonon focusing effects apparent in the phonon imaging data. The degree of interface transparency to phonons and resulting phonon propagation modes correlate with the structure of the interface following eutectic solidification. Structural studies of samples with initial Au thickness of 1,000 {angstrom}/side appear to correspond with the phonon transmission study.

Knowlton, W.B. [Univ. of California, Berkeley, CA (United States). Dept. of Materials Science and Mineral Engineering]|[Lawrence Berkeley Lab., CA (United States). Materials Sciences Div.

1995-07-01T23:59:59.000Z

103

Stable, free-standing Ge nanocrystals  

SciTech Connect (OSTI)

Free-standing Ge nanocrystals that are stable under ambient conditions have been synthesized in a two-step process. First, nanocrystals with a mean diameter of 5 nm are grown in amorphous SiO{sub 2} by ion implantation followed by thermal annealing. The oxide matrix is then removed by selective etching in diluted HF to obtain free-standing nanocrystals on a Si wafer. After etching, nanocrystals are retained on the surface and the size distribution is not significantly altered. Free-standing nanocrystals are stable under ambient atmospheric conditions, suggesting formation of a self-limiting native oxide layer. For free-standing as opposed to embedded Ge nanocrystals, an additional amorphous-like contribution to the Raman spectrum is observed and is assigned to surface reconstruction-induced disordering of near-surface atoms.

Sharp, I.D.; Xu, Q.; Liao, C.Y.; Yi, D.O.; Beeman, J.W.; Liliental-Weber, Z.; Yu, K.M.; Zakharov, D.N.; Ager III, J.W.; Chrzan,D.C.; Haller, E.E.

2005-01-28T23:59:59.000Z

104

FIRST STUDY OF DARK MATTER PROPERTIES WITH DETECTED SOLAR GRAVITY MODES AND NEUTRINOS  

SciTech Connect (OSTI)

We derive new limits on the cold dark matter properties for weakly interacting massive particles (WIMPs), potentially trapped in the solar core by using for the first time the central temperature constrained by boron neutrinos and the central density constrained by the dipolar gravity modes detected with the Global Oscillations at Low Frequency/Solar Helioseismic Observatory instrument. These detections disfavor the presence of non-annihilating WIMPs for masses {<=}10 GeV and spin dependent cross-sections >5 Multiplication-Sign 10{sup -36} cm{sup 2} in the solar core but cannot constrain WIMP annihilation models. We suggest that in the coming years helio- and asteroseismology will provide complementary probes of dark matter.

Turck-Chieze, S.; Garcia, R. A. [CEA/DSM/IRFU/SAp-AIM, CE Saclay, Orme des Merisiers, 91191 Gif-sur-Yvette (France); Lopes, I. [Centro Multidisciplinar de Astrofisica, Instituto Superior Tecnico, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Ballot, J. [Institut de Recherche en Astrophysique et Planetologie, CNRS, 14 avenue Edouard Belin and Universite de Toulouse, UPS-OMP, IRAP, 31400 Toulouse (France); Couvidat, S. [W.W. Hansen. E. P. L., Stanford University, Stanford, CA 94305 (United States); Mathur, S. [High Altitude Observatory, NCAR, P.O. Box 3000, Boulder, CO 80307 (United States); Salabert, D. [CNRS, Observatoire de la Cote d'Azur, Universite de Nice Sophia-Antipolis, BP 4229, 06304 Nice Cedex 4 (France); Silk, J., E-mail: Sylvaine.Turck-Chieze@cea.fr [UPMC-CNRS, UMR7095, Institut d'Astrophysique de Paris, F-75014 Paris (France)

2012-02-10T23:59:59.000Z

105

Neutrino Physics and Dark Matter Physics with Ultra-Low-Energy Germanium Detector  

SciTech Connect (OSTI)

The status and plans of the TEXONO Collaboration on the development of ultra-low-energy germanium detectors with sub-keV sensitivities are reported. We survey the scientific goals which include the observation of neutrino-nucleus coherent scattering, the studies of neutrino magnetic moments, as well as the searches of WIMP dark matter. In particular, an energy threshold of 220{+-}10 eV at an efficiency of 50% were achieved with a four-channel prototype detectors each of an active mass of 5 g. New limits were set for WIMPs with mass between 3-6 GeV. The prospects of the realization of full-scale experiments are discussed. This detector technique makes the unexplored sub-keV energy window accessible for new neutrino and dark matter experiments.

Shin-Ted, Lin [Institute of Physics, Academia Sinica, Taipei 11529, Taiwan (China)

2008-10-10T23:59:59.000Z

106

Latest Results of the Edelweiss-II Dark Matter Search Experiment  

SciTech Connect (OSTI)

A search for WIMP dark matter has been undertaken with new-generation germanium heat-and-ionization cryogenic detectors in the EDELWEISS-II experiment. The InterDigit bolometers, with an interleaved electrode design, have proven excellent rejection performance against gamma-ray and surface event backgrounds which are limiting germanium bolometer dark matter searches. One year of continuous operation at the Laboratoire Souterrain de Modane has been achieved with an array of ten 400 g detectors. Preliminary resultats for WIMP search are presented with an effective exposure of 322 kg.days, which corresponds to a 5x10{sup -8} pb sensitivity to the spin independant WIMP-nucleon cross-section at 90% C.L. for a WIMP mass of 80 GeV/c{sup 2}.

Loaiza, P. [Laboratoire Souterrain de Modane, CEA-CNRS, 1125 route de Bardonneche, 73500 Modane (France)

2011-04-27T23:59:59.000Z

107

Quark Matter  

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

Quark Quark Matter in Neutron Stars Prashanth Jaikumar Argonne National Laboratory, (PHY) September 7th, 2006 . - p.1/29 Outline * Neutron stars: observations by a theorist . - p.2/29 Outline * Neutron stars: observations by a theorist * Mass-Radius constraints on Equation of State (EoS) . - p.2/29 Outline * Neutron stars: observations by a theorist * Mass-Radius constraints on Equation of State (EoS) * Is quark matter inside neutron stars ruled out? . - p.2/29 Outline * Neutron stars: observations by a theorist * Mass-Radius constraints on Equation of State (EoS) * Is quark matter inside neutron stars ruled out? ------------------------ * Strange Quark stars: Features and "Findings" . - p.2/29 Outline * Neutron stars: observations by a theorist * Mass-Radius constraints on Equation of State (EoS) * Is quark matter inside neutron stars ruled out? ------------------------

108

Thermodynamics of clusterized matter  

E-Print Network [OSTI]

Thermodynamics of clusterized matter is studied in the framework of statistical models with non-interacting cluster degrees of freedom. At variance with the analytical Fisher model, exact Metropolis simulation results indicate that the transition from homogeneous to clusterized matter lies along the $\\rho=\\rho_0$ axis at all temperatures and the limiting point of the phase diagram is not a critical point even if the surface energy vanishes at this point. Sensitivity of the inferred phase diagram to the employed statistical framework in the case of finite systems is discussed by considering the grand-canonical and constant-pressure canonical ensembles. A Wigner-Seitz formalism in which the fragment charge is neutralized by an uniform electron distribution allows to build the phase diagram of neutron star matter.

Ad. R. Raduta; F. Gulminelli

2009-02-28T23:59:59.000Z

109

Results on neutrinoless double beta decay of 76 Ge from Gerda Phase I  

E-Print Network [OSTI]

Results on neutrinoless double beta decay of 76 Ge from Gerda Phase I M. Agostini,14 M. Allardt,3 E and a lower limit is derived for the half-life of neutrinoless double beta decay of 76 Ge, T0 1/2> 2.1 · 1025 double beta decay of the isotope 76 Ge. Data con- sidered in the present analysis have been collected

110

2 Apr 2009 "Shedding Light on Dark Matter", LHC Status and SUSY  

E-Print Network [OSTI]

2 Apr 2009 "Shedding Light on Dark Matter", U MD 1 LHC Status and SUSY Search Preparations Sarah Light on Dark Matter", U MD 2 · Can look for the ambient dark matter all around us using nuclear recoils,659 m. Injector: SPS Injected beam energy: 450 GeV (protons) Nominal beam energy in physics: 7 Te

Maryland at College Park, University of

111

Natural Gas Locomotive | GE Global Research  

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

government. GE engineers are currently testing a fuel mixture that is 80% LNG, and 20% diesel using existing engine hardware. GE engineers continue to address several challenges...

112

New Medical Technology | GE Global Research  

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

of care and expanding medical treatment boundaries. Home > Innovation > Healthcare Additive Manufacturing Demonstration at GE Global Research See how GE Global Research is...

113

Hospital Sterile Processing | GE Global Research  

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

Researches Use of Robots for Hospital Sterile Processing GE Researches Use of Robots for Hospital Sterile Processing GE principal investigator Lynn DeRose discusses the robotic...

114

Oil & Gas Technology Center | GE Global Research  

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

Global Research Oil & Gas Technology Center GE Global Research Oil & Gas Technology Center Mark Little, SVP and chief technology officer for GE, and Eric Gebhardt, vice president...

115

GE Innovation and Manufacturing in Europe | GE Global Research  

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

Wins Award 1-2-38-v-software-reliability-engineering A Stochastic Process-Based Look at Software Reliability 2-1-10-v-working-at-ge-research The Dirt on the Cleanroom...

116

GE Global Research Europe, Munich, Germany | GE Global Research  

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

Munich, Germany Munich, Germany With a hand in nearly all GE research fields, this center is a hub of commercial and industrial science and technology innovation. Visit the Careers...

117

4.3.2 Ge spinels and Ge spinels with substitutions  

Science Journals Connector (OSTI)

Al-Ge-Li-O-Zn: Li5Al5Zn8Ge9O36 (Sp). Al-Ge-Li-O: Li0.5+0.5xGexAl2.5-1.5xO4 (Sp). Al-Ge-O-Zn: Zn2GeO4: Al (Sp). Co-Fe-Ge-O: Co2-2xFe2xGeO4 (Sp). Co-Ge-L-Li-O: Co0.5LiGeL5O4 (Sp). Co-Ge-Mg-O: Co2-x

D. Bonnenberg; K. A. Hempel

1980-01-01T23:59:59.000Z

118

Cosmology, Thermodynamics and Matter Creation  

E-Print Network [OSTI]

Several approaches to the matter creation problem in the context of cosmological models are summarily reviewed. A covariant formulation of the general relativistic imperfect simple fluid endowed with a process of matter creation is presented. By considering the standard big bang model, it is shown how the recent results of Prigogine et alii \\cite{1} can be recovered and, at the same time their limits of validity are explicited.

J. A. S. Lima; M. O. Calvao; I. Waga

2007-08-24T23:59:59.000Z

119

Double-Disk Dark Matter  

Science Journals Connector (OSTI)

Abstract Based on observational tests of large scale structure and constraints on halo structure, dark matter is generally taken to be cold and essentially collisionless. On the other hand, given the large number of particles and forces in the visible world, a more complex dark sector could be a reasonable or even likely possibility. This hypothesis leads to testable consequences, perhaps portending the discovery of a rich hidden world neighboring our own. We consider a scenario that readily satisfies current bounds that we call Partially Interacting Dark Matter (PIDM). This scenario contains self-interacting dark matter, but it is not the dominant component. Even if PIDM contains only a fraction of the net dark matter density, comparable to the baryonic fraction, the subdominant components interactions can lead to interesting and potentially observable consequences. Our primary focus will be the special case of Double-Disk Dark Matter (DDDM), in which self-interactions allow the dark matter to lose enough energy to lead to dynamics similar to those in the baryonic sector. We explore a simple model in which DDDM can cool efficiently and form a disk within galaxies, and we evaluate some of the possible observational signatures. The most prominent signal of such a scenario could be an enhanced indirect detection signature with a distinctive spatial distribution. Even though subdominant, the enhanced density at the center of the galaxy and possibly throughout the plane of the galaxy (depending on precise alignment) can lead to large boost factors, and could even explain a signature as large as the 130 GeV Fermi line. Such scenarios also predict additional dark radiation degrees of freedom that could soon be detectable and would influence the interpretation of future data, such as that from Planck and from the Gaia satellite. We consider this to be the first step toward exploring a rich array of new possibilities for dark matter dynamics.

JiJi Fan; Andrey Katz; Lisa Randall; Matthew Reece

2013-01-01T23:59:59.000Z

120

MEMS Relays | GE Global Research  

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

MEMS Technology 2-1-7-v-metal-mems-devices MEMS: Inside the Global Research Cleanroom 2-3-11-v Carousolar Uses Solar Power for Fun 2-2-6-v GE Scientists Demonstrate...

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


121

Laser Additive Manufacturing in GE  

Science Journals Connector (OSTI)

There has been an increasing interest given to laser additive manufacturing (LAM) in recent years from across the global. GE has been one of the leading industries engaging in this...

Peng, Henry; Li, Yanmin; Guo, Rui; Wu, Zhiwei

122

GE computer move in Japan  

Science Journals Connector (OSTI)

GE computer move in Japan ... General Electric is moving ahead with plans to set up a joint computer venture in Japan with Tokyo Shibaura Electric (Toshiba) and Mitsubishi Electric. ... Later, possibly in about three years, it will manufacture in Japan. ...

1967-02-06T23:59:59.000Z

123

Super-Resolution ROM Disc Using GeAl Reflective Absorption Layer  

Science Journals Connector (OSTI)

We have developed a super-resolution ROM disc using a newly designed GeAl reflective absorption layer. The optical resolution limit in high readout power expanded more than 1.5 times...

Aoki, Kazuhiko; Tanabe, Hideki; Ohkubo, Shuichi; Kariyada, Eiji; Katayama, Ryuichi; Yamanaka, Yutaka

124

New Limits On Gamma-Ray Emission From Galaxy Clusters  

E-Print Network [OSTI]

Galaxy clusters are predicted to produce gamma-rays through cosmic ray interactions and/or dark matter annihilation, potentially detectable by the Fermi Large Area Telescope (Fermi-LAT). We present a new, independent stacking analysis of Fermi-LAT photon count maps using the 79 richest nearby clusters (zSurvey (2MASS) cluster catalog. We obtain the lowest limit on the photon flux to date, 1.1e-11 ph/s/cm^2 (95% confidence) per cluster in the 0.8--100~GeV band, which corresponds to a luminosity limit of 1.7e44 ph/s. We also constrain the emission limits in a range of narrower energy bands. Scaling to recent cosmic ray acceleration and gamma-ray emission models, we find that cosmic rays represent a negligible contribution to the intra-cluster energy density and gas pressure. Furthermore, either accretion shocks must have lower Mach numbers than usually assumed (2--4) or significantly less than 50% of the baryon mass has been processed through such shocks, and thus, the majo...

Griffin, Rhiannon D; Kochanek, Christopher S

2014-01-01T23:59:59.000Z

125

Pseudo-Goldstone modes in isospin-asymmetric nuclear matter  

SciTech Connect (OSTI)

The authors analyze the chiral limit in dense isospin-asymmetric nuclear matter. It is shown that the pseudo-Goldstone modes in this system are qualitatively different from the case of isospin-symmetric matter.

Cohen, T.D. [Univ. of Washington, Seattle, WA (United States); Broniowski, W. [H. Niewodniczanski Institute of Nuclear Physics, Cracow (Poland)

1995-01-01T23:59:59.000Z

126

Constraints on particle dark matter from cosmic-ray antiprotons  

E-Print Network [OSTI]

Cosmic-ray antiprotons represent an important channel for dark matter indirect-detection studies. Current measurements of the antiproton flux at the top of the atmosphere and theoretical determinations of the secondary antiproton production in the Galaxy are in good agreement, with no manifest deviation which could point to an exotic contribution in this channel. Therefore, antiprotons can be used as a powerful tool for constraining particle dark matter properties. By using the spectrum of PAMELA data from 50 MV to 180 GV in rigidity, we derive bounds on the dark matter annihilation cross section (or decay rate, for decaying dark matter) for the whole spectrum of dark matter annihilation (decay) channels and under different hypotheses of cosmic-rays transport in the Galaxy and in the heliosphere. For typical models of galactic propagation, the constraints are significantly strong, setting a lower bound on the dark matter mass of a "thermal" relic at about 50 -- 90 GeV for hadronic annihilation channels. These bounds are enhanced to about 150 GeV on the dark matter mass, when large cosmic-rays confinement volumes in the Galaxy are considered, and are reduced to 4-5 GeV for annihilation to light quarks (no bound for heavy-quark production) when the confinement volume is small. Bounds for dark matter lighter than few tens of GeV are due to the low energy part of the PAMELA spectrum, an energy region where solar modulation is relevant: to this aim, we have implemented a detailed solution of the transport equation in the heliosphere, which allowed us not only to extend bounds to light dark matter, but also to determine the uncertainty on the constraints arising from solar modulation modeling. Finally, we estimate the impact of soon-to-come AMS-02 data on the antiproton constraints.

N. Fornengo; L. Maccione; A. Vittino

2013-12-12T23:59:59.000Z

127

Constraints on particle dark matter from cosmic-ray antiprotons  

E-Print Network [OSTI]

Cosmic-ray antiprotons represent an important channel for dark matter indirect-detection studies. Current measurements of the antiproton flux at the top of the atmosphere and theoretical determinations of the secondary antiproton production in the Galaxy are in good agreement, with no manifest deviation which could point to an exotic contribution in this channel. Therefore, antiprotons can be used as a powerful tool for constraining particle dark matter properties. By using the spectrum of PAMELA data from 50 MV to 180 GV in rigidity, we derive bounds on the dark matter annihilation cross section (or decay rate, for decaying dark matter) for the whole spectrum of dark matter annihilation (decay) channels and under different hypotheses of cosmic-rays transport in the Galaxy and in the heliosphere. For typical models of galactic propagation, the constraints are significantly strong, setting a lower bound on the dark matter mass of a "thermal" relic at about 50-90 GeV for hadronic annihilation channels. These bounds are enhanced to about 150 GeV on the dark matter mass, when large cosmic-rays confinement volumes in the Galaxy are considered, and are reduced to 4-5 GeV for annihilation to light quarks (no bound for heavy-quark production) when the confinement volume is small. Bounds for dark matter lighter than few tens of GeV are due to the low energy part of the PAMELA spectrum, an energy region where solar modulation is relevant: to this aim, we have implemented a detailed solution of the transport equation in the heliosphere, which allowed us not only to extend bounds to light dark matter, but also to determine the uncertainty on the constraints arising from solar modulation modeling. Finally, we estimate the impact of soon-to-come AMS-02 data on the antiproton constraints.

N. Fornengo; L. Maccione; A. Vittino

2015-01-30T23:59:59.000Z

128

7-GeV Advanced Photon Source Conceptual Design Report  

SciTech Connect (OSTI)

During the past decade, synchrotron radiation emitted by circulating electron beams has come into wide use as a powerful, versatile source of x-rays for probing the structure of matter and for studying various physical processes. Several synchrotron radiation facilities with different designs and characteristics are now in regular operation throughout the world, with recent additions in this country being the 0.8-GeV and 2.5-GeV rings of NSLS at Brookhaven National Laboratory. However, none of the operating facilities has been designed to use a low-emittance, high-energy stored beam, together with modern undulator devices, to produce a large number of hard x-ray beams of extremely high brilliance. This document is a proposal to the Department of Energy to construct and operate high-energy synchrotron radiation facility at Argonne National Laboratory. We have now chosen to set the design energy of this facility at 7.0 GeV, with the capability to operate at up to 7.5 GeV.

Not Available

1987-04-01T23:59:59.000Z

129

Asymmetric dark matter and the Sun  

E-Print Network [OSTI]

Cold dark matter particles with an intrinsic matter-antimatter asymmetry do not annihilate after gravitational capture by the Sun and can affect its interior structure. The rate of capture is exponentially enhanced when such particles have self-interactions of the right order to explain structure formation on galactic scales. A `dark baryon' of mass 5 GeV is a natural candidate and has the required relic abundance if its asymmetry is similar to that of ordinary baryons. We show that such particles can solve the `solar composition problem'. The predicted small decrease in the low energy neutrino fluxes may be measurable by the Borexino and SNO+ experiments.

Mads T. Frandsen; Subir Sarkar

2010-06-01T23:59:59.000Z

130

Kinetic study of GeO disproportionation into a GeO{sub 2}/Ge system using x-ray photoelectron spectroscopy  

SciTech Connect (OSTI)

GeO disproportionation into GeO{sub 2} and Ge is studied through x-ray photoelectron spectroscopy. Direct evidence for the reaction 2GeO {yields} GeO{sub 2} + Ge after annealing in ultra-high vacuum is presented. Activation energy for GeO disproportionation is found to be about 0.7 {+-} 0.2 eV through kinetic and thermodynamic calculations. A kinetic model of GeO disproportionation is established by considering oxygen transfer in the GeO network. The relationship between GeO disproportionation and GeO desorption induced by GeO{sub 2}/Ge interfacial reaction is discussed, and the apparent contradiction between GeO desorption via interfacial redox reaction and GeO disproportionation into Ge and GeO{sub 2} is explained by considering the oxygen vacancy.

Wang Shengkai [Micorowave Devices and Integrated Circuits Department, Institute of Microelectronics, Chinese Academy of Sciences, 3 Bei-Tu-Cheng West Road, Beijing 100029 (China); Department of Materials Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); CREST, Japan Science and Technology Agency (JST), 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Liu Honggang [Microwave Devices and Integrated Circuits Department, Institute of Microelectronics, Chinese Academy of Sciences, 3 Bei-Tu-Cheng West Road, Beijing 100029 (China); Toriumi, Akira [Department of Materials Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); CREST, Japan Science and Technology Agency (JST), 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan)

2012-08-06T23:59:59.000Z

131

GE PowerPoint Template  

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

Steels for Steels for Accident Tolera nt Fuel Cla ddings Ferritic Ma rtensitic Alloys a s Accident Tolera nt Fuel (ATF) Cla dding Ma teria l for Light Wa ter Rea ctors Ra ul B. Reba k, GE Globa l Resea rch DOE Integra tion Meeting, Sa lt La ke City 27-August-2013 DE NE 568 2 / GE Reba k - DOE Integra tion Meeting, Sa lt La ke City, 27-August-2013/ GE Project Tea m 3 / GE Reba k - DOE Integra tion Meeting, Sa lt La ke City, 27-August-2013/ Approa ch of GE Resea rch Proposa l * Demonstra te tha t sta inless iron ba sed bulk a lloys or Adva nced Steels ca n be used a s fuel cla dding ma teria ls in commercia l nuclea r rea ctors * The proposed ma teria l should be a s good a s Zr a lloys (or better tha n Zr a lloys) under norma l opera tion conditions 1. Resista nt to genera l corrosion a nd environmenta l cra

132

Hybrid Locomotive | GE Global Research  

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

two main culprits: nitrogen oxide (NOx) and particulate matter (PM) like tiny chemical, metal, soil and dust particles. Tier 4 emission standards will kick in for locomotives on...

133

GE Teams with NY College to Pilot SOFC Technology |GE Global...  

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

Hudson Valley Community College to Pilot GE Solid Oxide Fuel Cell Technology Hudson Valley Community College to Pilot GE Solid Oxide Fuel Cell Technology GE - Fuel Cells to install...

134

Cs4(In0.27Ge0.73)15Ge8  

Science Journals Connector (OSTI)

It contains the standardized crystallographic data set of Cs8In8Ge38 representing the structure type Cs4(In0.27Ge0.73)15Ge8.

P. Villars; K. Cenzual; J. Daams

2004-01-01T23:59:59.000Z

135

Ba6(In0.36Ge0.64)11Ge14  

Science Journals Connector (OSTI)

It contains the standardized crystallographic data set of Ba6In4Ge21 representing the structure type Ba6(In0.36Ge0.64)11Ge14.

P. Villars; K. Cenzual; J. Daams

2005-01-01T23:59:59.000Z

136

Lorentz violation and Condensed Matter Physics  

E-Print Network [OSTI]

We present heuristic arguments that hint to a possible connection of Lorentz violation with observed phenomenon in condensed matter physics. Various references from condensed matter literature are cited where operators in the Standard Model Extension (SME) appear to be enhanced. Based on this we propose that, in the non-relativistic limit, Lorentz violation in the context of the SME exhibits itself in various condensed matter systems.

Muhammad Adeel Ajaib

2014-03-29T23:59:59.000Z

137

Tensor Detection Severely Constrains Axion Dark Matter  

E-Print Network [OSTI]

The recent detection of tensor modes by BICEP2 has non-trivial implications for axion dark matter implied by combining the tensor detection with isocurvature constraints from Planck. In this paper the measurement is taken as fact, and its implications considered, though further experimental verification is required. In the simplest inflation models $r=0.2$ implies $H_I=1.1\\times 10^{14}\\text{ GeV}$. If the axion decay constant $f_a>H_I$ then isocurvature constraints effectively rule out the QCD axion as dark matter for $m_a \\lesssim 0.06\\mu$ eV, contributing only a fraction $\\Omega_a/\\Omega_d\\lesssim 10^{-11}(f_a/10^{16}\\text{ GeV})^{5/6}$ (where $\\Omega_i$ is the fraction of the critical density), with misalignment angle $\\theta_i\\lesssim 3.1 \\times 10^{-8}(f_a/10^{16}\\text{ GeV})^{-1/6}$ . Implications of this fine tuning are discussed. Constraints on axion-like particles, as a function of their mass and dark matter fraction are also considered. For heavy axions with $m_a\\gtrsim 10^{-22}\\text{ eV}$ we find ...

Marsh, David J E; Hlozek, Renee; Ferreira, Pedro G

2014-01-01T23:59:59.000Z

138

Clean Cities: National Clean Fleets Partner: GE  

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

GE to GE to someone by E-mail Share Clean Cities: National Clean Fleets Partner: GE on Facebook Tweet about Clean Cities: National Clean Fleets Partner: GE on Twitter Bookmark Clean Cities: National Clean Fleets Partner: GE on Google Bookmark Clean Cities: National Clean Fleets Partner: GE on Delicious Rank Clean Cities: National Clean Fleets Partner: GE on Digg Find More places to share Clean Cities: National Clean Fleets Partner: GE on AddThis.com... Goals & Accomplishments Partnerships National Clean Fleets Partnership National Parks Initiative Electric Vehicle Infrastructure Training Program Advanced Vehicle Technology Competitions Natural Gas Transit & School Bus Users Group Natural Gas Vehicle Technology Forum Hall of Fame Contacts National Clean Fleets Partner: GE

139

Beyond the standard Higgs after the 125 GeV Higgs discovery  

Science Journals Connector (OSTI)

...behind and beyond the discovery of the Higgs boson...after the 125 GeV Higgs discovery C. Grojean e-mail...behind and beyond the discovery of the Higgs boson...Model up to very high energy, maybe as high as the...fill the universe with dark matter and does not...

2015-01-01T23:59:59.000Z

140

The Jefferson Lab 12 GeV program on nucleon structure  

SciTech Connect (OSTI)

This slide-show presents the experiments planned at JLab with their 12 GeV upgrade. Experiments reported address: the use of hadron spectra as probes of QCD; the transverse structure of hadrons; the longitudinal structure of hadrons; the 3-dimensional structure of hadrons; hadrons and cold nuclear matter; and low-energy tests of the Standard Model and fundamental symmetries.

Burkert, Volker D. [JLAB

2013-10-01T23:59:59.000Z

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


141

GE Energy Formerly GE Power Systems | Open Energy Information  

Open Energy Info (EERE)

GE Power Systems GE Power Systems Jump to: navigation, search Name GE Energy (Formerly GE Power Systems) Place Atlanta, Georgia Zip 30339 Sector Renewable Energy, Solar, Wind energy Product Atlanta-based supplier of power generation and energy delivery technologies in all areas of the energy industry including renewable resources such as water, wind, solar and alternative fuels. Coordinates 33.748315°, -84.391109° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":33.748315,"lon":-84.391109,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

142

Cosmic-ray electron signatures of dark matter  

SciTech Connect (OSTI)

There is evidence for an excess in cosmic-ray electrons at about 500 GeV energy, that may be related to dark-matter annihilation. I have calculated the expected electron contributions from a pulsar and from Kaluza-Klein dark matter, based on a realistic treatment of the electron propagation in the Galaxy. Pulsars younger than about 10{sup 5} years naturally cause a narrow peak at a few hundred GeV in the locally observed electron spectrum, similar to that observed. On the other hand, if electron production by dark matter is predominantly occurring in high-mass clumps (> or approx. 10{sup 3}M{sub {center_dot}}), the sharp cutoff in the contribution from Kaluza-Klein particles is sometimes more pronounced, but often smoothed out and indistinguishable from a pulsar source, and therefore the spectral shape of the electron excess is insufficient to discriminate a dark-matter origin from more conventional astrophysical explanations.

Pohl, Martin [Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011 (United States)

2009-02-15T23:59:59.000Z

143

Hot Hole p-Ge Lasers and Masers for Spectroscopy of MultiQuantum-Well Heterostructures Ge/Ge1-xSix  

Science Journals Connector (OSTI)

Hot hole p-Ge masers and lasers operating in millimiter and ... of the tunable spectrometer with hote hole p-Ge emitter is demostrated by its application to ... multi-quantum-well (MQW) heterostructures (HS) Ge/Ge

V. V. Nikonorov; V. I. Gavrilenko

1995-01-01T23:59:59.000Z

144

Ge-nanocluster formation in Ge-doped polysilicon films under oxidation and heat treatment  

Science Journals Connector (OSTI)

An experimental investigation is conducted into the formation Ge nanoclusters by heat treatment of germanosilicate-glass... x Ge y O ...

A. A. Kovalevsky; A. S. Strogova; D. V. Plyakin

2009-03-01T23:59:59.000Z

145

Direct Search for Low Mass Dark Matter Particles with CCDs  

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

A direct dark matter search is performed using fully-depleted high-resistivity CCD detectors. Due to their low electronic readout noise (RMS ~7 eV) these devices operate with a very low detection threshold of 40 eV, making the search for dark matter particles with low masses (~5 GeV) possible. The results of an engineering run performed in a shallow underground site are presented, demonstrating the potential of this technology in the low mass region.

Barreto, J [Rio de Janeiro Federal U.; Cease, H.; Diehl, H.T.; Estrada, J.; Flaugher, B.; Harrison, N.; Jones, J.; Kilminster, B [Fermilab; Molina, J [Asuncion Natl. U.; Smith, J.; Sonnenschein, A [Fermilab

2012-05-15T23:59:59.000Z

146

Technology "Relay Race" Against Cancer | GE Global Research  

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

GE Scientists in Technology "Relay Race" Against Cancer GE Scientists in Technology "Relay Race" Against Cancer GE technologies being developed to impact every stage of cancer...

147

Crowdsourcing Software Award | GE Global Research  

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

GE Unveils High-Tech Superhero, GENIUS MAN MunichinteriorV 10 Years ON: From the Lab to the Real World in 10 Years 2-1-10-v-working-at-ge-research The Dirt on the Cleanroom...

148

Work and Life Balance | GE Global Research  

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

Achieving worklife balance is a much-talked-about topic. According to GE Healthcare's Kelly Piacsek, "GE hires people for what's inside their head-what they know-and the specific...

149

Hauptbewsserungs(ge)rinne f, (n)  

Science Journals Connector (OSTI)

Hauptbewsserungs(ge)rinne f, (n) ? supply (irrigation) channel [The main channel supplying water to the irrigation area

2013-01-01T23:59:59.000Z

150

Dose Limits  

Broader source: Energy.gov [DOE]

Dose Limits ERAD (Question Posted to ERAD in May 2012) Who do you define as a member of the public for the onsite MEI? This question implies that there may be more than one maximally exposed individual (MEI), one on-site and one off-site, when demonstrating compliance with the Public Dose Limit of DOE Order 458.1. Although all potential MEIs should be considered and documented, as well as the calculated doses and pathways considered, the intent of DOE Order 458.1 is in fact to ultimately identify only one MEI, a theoretical individual who could be either on-site or off-site.

151

The Fermi Large Area gamma ray Telescope and the current searches for dark matter in space  

E-Print Network [OSTI]

production [6],[7] [9]. The temptation to claim the discovery of dark matter is strongThe Fermi Large Area gamma ray Telescope and the current searches for dark matter in space Aldo Gamma-ray Space Telescope, has detected the largest amount of gamma rays, in the 20MeV 300GeV energy

Morselli, Aldo

152

Baryons and Dark Matter from the Late Decay of a Supersymmetric Condensate  

E-Print Network [OSTI]

The possibility that both the baryon asymmetry and dark matter arise from the late decay of a population of supersymmetric particles is considered. If the decay takes place below the LSP freeze out temperature, a nonthermal distribution of LSPs results. With conserved $R$ parity these relic LSPs contribute to the dark matter density. A net asymmetry can exist in the population of decaying particles if it arises from coherent production along a supersymmetric flat direction. The asymmetry is transferred to baryons if the condensate decays through the lowest order nonrenormalizable operators which couple to $R$ odd combinations of standard model particles. This also ensures at least one LSP per decay. The relic baryon and LSP number densities are then roughly equal. The ratio of baryon to dark matter densities is then naturally $\\Omegab / \\OmegaLSP \\sim {\\cal O}(\\mb / \\mLSP)$. The resulting upper limit on the LSP mass is model dependent but in the range ${\\cal O}(30-140)$ GeV. The total relic density is related to the order at which the flat direction which gives rise to the condensate is lifted. The observed density is obtained for a direction which is lifted by a fourth order Planck scale suppressed operator in the superpotential.

Scott Thomas

1995-06-09T23:59:59.000Z

153

Stable Higgs Bosons as Cold Dark Matter  

E-Print Network [OSTI]

In a class of the gauge-Higgs unification models the 4D neutral Higgs boson, which is a part of the extra-dimensional component of the gauge fields, becomes absolutely stable as a consequence of the gauge invariance and dynamically generated new parity, serving as a promising candidate for cold dark matter (CDM). We show that the observed relic abundance of cold dark matter is obtained in the SO(5) x U(1) model in the warped space with the Higgs mass around 70 GeV. The Higgs-nucleon scattering cross section is found to be close to the current CDMS II and XENON10 bounds in the direct detection of dark matter.

Yutaka Hosotani; Pyungwon Ko; Minoru Tanaka

2009-08-03T23:59:59.000Z

154

Spectrum of electron-hole states of the Si/Ge structure with Ge quantum dots  

SciTech Connect (OSTI)

The lateral photoconductivity spectra of Si/Ge multilayer structures with Ge quantum dots of various sizes are investigated. We observed optical transition lines between the hole levels of quantum dots and electronic states of Si. This enabled us to construct a detailed energy level diagram of the electron-hole spectrum of the Si/Ge structures. It is shown that the hole levels of Ge quantum dots are successfully described by the 'quantum box' model using the actual sizes of Ge islands. It I found that the position of the longwavelength photosensitivity boundary of Si/Ge structures with Ge quantum dots can be controlled by changing the growth parameters.

Talochkin, A. B., E-mail: tal@thermo.isp.nsc.ru; Chistokhin, I. B., E-mail: igor@thermo.isp.nsc.ru [Russian Academy of Sciences, Institute of Semiconductor Physics, Siberian Branch (Russian Federation)

2011-09-15T23:59:59.000Z

155

Limits on Sensitivity of Large Silicon Bolometers for Solar Neutrino Detection  

Science Journals Connector (OSTI)

...F.T., ULTRALOW-BACKGROUND STUDY OF NEUTRINOLESS DOUBLE BETA-DECAY OF GE-76 - NEW LIMIT ON THE MAJORANA MASS...FORSTER, A, LOW BACKGROUND STUDY OF THE NEUTRINOLESS DOUBLE BETA-DECAY OF 76-GE AND UPPER LIMIT FOR NEUTRINO MASS...

C. J. MARTOFF

1987-07-31T23:59:59.000Z

156

Search for muon signal from dark matter annihilations in the Sun with the Baksan Underground Scintillator Telescope for 24.12 years  

SciTech Connect (OSTI)

We present a new dataset analysis of the neutrino experiment at the Baksan Underground Scintillator Telescope with muon energy threshold about 1 GeV for the longest exposure time toward the Sun. In search for a signal from self-annihilations of dark matter particles in the center of the Sun we use an updated sample of upward through-going muons for 24.12 years of live time. No observable excess has been found in measured muons relative to expected background from neutrinos of atmospheric origin. We present an improved data analysis procedure and describe it in detail. We set the 90% C.L. new upper limits on expected neutrino and muon fluxes from dark matter annihilations in the Sun, on the corresponding annihilation rates and cross sections of their elastic scattering off proton.

Boliev, M.M. [Institute for Nuclear Research of Russian Academy of Sciences, Baksan Neutrino Observatory, Kabardino-Balkariya 400900 (Russian Federation); Demidov, S.V.; Mikheyev, S.P.; Suvorova, O.V., E-mail: boliev2005@yandex.ru, E-mail: demidov@ms2.inr.ac.ru, E-mail: mikheyev@pcbai10.inr.ruhep.ru, E-mail: suvorova@cpc.inr.ac.ru [Institute for Nuclear Research of Russian Academy of Sciences, prospect 60-th October 7A, Moscow 117312 (Russian Federation)

2013-09-01T23:59:59.000Z

157

Moisture Matters | EMSL  

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

Moisture Matters Moisture Matters Cryogenic microscopy methods yield insights to microbial morphology State-of-the-art cryogenic electron microscopy (EM) approaches at EMSL are...

158

Dark Matter Theory  

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

Dark Matter Theory Dark Matter Theory Understanding discoveries at the Energy, Intensity, and Cosmic Frontiers Get Expertise Rajan Gupta (505) 667-7664 Email Bruce Carlsten (505)...

159

Diurnal modulation due to self-interacting mirror and hidden sector dark matter  

SciTech Connect (OSTI)

Mirror and more generic hidden sector dark matter models can simultaneously explain the DAMA, CoGeNT and CRESST-II dark matter signals consistently with the null results of the other experiments. This type of dark matter can be captured by the Earth and shield detectors because it is self-interacting. This effect will lead to a diurnal modulation in dark matter detectors. We estimate the size of this effect for dark matter detectors in various locations. For a detector located in the northern hemisphere, this effect is expected to peak in April and can be detected for optimistic parameter choices. The diurnal variation is expected to be much larger for detectors located in the southern hemisphere. In particular, if the CoGeNT detector were moved to e.g. Sierra Grande, Argentina then a 5? dark matter discovery would be possible in around 30 days of operation.

Foot, R., E-mail: rfoot@unimelb.edu.au [ARC Centre of Excellence for Particle Physics at the Terascale, School of Physics, University of Melbourne, Melbourne, Victoria 3010 (Australia)

2012-04-01T23:59:59.000Z

160

GE Appliances and Lighting Home Energy Solutions  

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

GE Appliances and Lighting GE Appliances and Lighting Home Energy Solutions Introduction to Devices with Brillion(tm) Technology Portfolio of Products 3 GE Appliances and Lighting All Rights Reserved Brillion(tm) Suite of Home Energy Solutions Nucleus(tm) Smart Meter Other Devices Internet IHD Other Devices PCT Non-Meter Solution GE DRMS GEA Server 4 GE Appliances and Lighting All Rights Reserved Nucleus(tm) energy manager with Brillion(tm) technology Consumers can reduce electric usage by an average of 5% per year. 5 GE Appliances and Lighting All Rights Reserved GE Profile Appliances enabled with Brillion(tm) technology Delayed defrost during peak Delayed starts and temperature adjustments during peak Delayed start until off- peak Reduced energy usage 60%, DR- enabled Reduced wattage during peak When coupled with the Nucleus and a TOU

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


161

Vacuum energy as dark matter  

Science Journals Connector (OSTI)

We consider the vacuum energy of massive quantum fields in an expanding universe. We define a conserved renormalized energy-momentum tensor by means of a comoving cutoff regularization. Using exact solutions for de Sitter space-time, we show that in a certain range of mass and renormalization scales there is a contribution to the vacuum energy density that scales as nonrelativistic matter and that such a contribution becomes dominant at late times. By means of the WKB approximation, we find that these results can be extended to arbitrary Robertson-Walker geometries. We study the range of parameters in which the vacuum energy density would be compatible with current limits on dark matter abundance. Finally, by calculating the vacuum energy in a perturbed Robertson-Walker background, we obtain the speed of sound of density perturbations and show that the vacuum energy density contrast can grow on sub-Hubble scales as in standard cold dark matter scenarios.

F.?D. Albareti; J.?A.?R. Cembranos; A.?L. Maroto

2014-12-05T23:59:59.000Z

162

Chiral condensate in neutron matter  

E-Print Network [OSTI]

A recent chiral perturbation theory calculation of the in-medium quark condensate $$ is extended to the isospin-asymmetric case of pure neutron matter. In contrast to the behavior in isospin-symmetric nuclear matter we find only small deviations from the linear density approximation. This feature originates primarily from the reduced weight factors (e.g. 1/6 for the dominant contributions) of the $2\\pi$-exchange mechanisms in pure neutron matter. Our result suggests therefore that the tendencies for chiral symmetry restoration are actually favored in systems with large neutron excess (e.g. neutron stars). We also analyze the behavior of the density-dependent quark condensate $(\\rho_n)$ in the chiral limit $m_\\pi\\to 0$.

N. Kaiser; W. Weise

2008-08-06T23:59:59.000Z

163

Mono-Higgs Detection of Dark Matter at the LHC  

E-Print Network [OSTI]

Motivated by the recent discovery of the Higgs boson, we investigate the possibility that a missing energy plus Higgs final state is the dominant signal channel for dark matter at the LHC. We consider examples of higher-dimension operators where a Higgs and dark matter pair are produced through an off-shell Z or photon, finding potential sensitivity at the LHC to cutoff scales of around a few hundred GeV. We generalize this production mechanism to a simplified model by introducing a Z' as well as a second Higgs doublet, where the pseudoscalar couples to dark matter. Resonant production of the Z' which decays to a Higgs plus invisible particles gives rise to a potential mono-Higgs signal. This may be observable at the 14 TeV LHC at low tan beta and when the Z' mass is roughly in the range 600 GeV to 1.3 TeV.

Berlin, Asher; Wang, Lian-Tao

2014-01-01T23:59:59.000Z

164

Mono-Higgs Detection of Dark Matter at the LHC  

E-Print Network [OSTI]

Motivated by the recent discovery of the Higgs boson, we investigate the possibility that a missing energy plus Higgs final state is the dominant signal channel for dark matter at the LHC. We consider examples of higher-dimension operators where a Higgs and dark matter pair are produced through an off-shell Z or photon, finding potential sensitivity at the LHC to cutoff scales of around a few hundred GeV. We generalize this production mechanism to a simplified model by introducing a Z' as well as a second Higgs doublet, where the pseudoscalar couples to dark matter. Resonant production of the Z' which decays to a Higgs plus invisible particles gives rise to a potential mono-Higgs signal. This may be observable at the 14 TeV LHC at low tan beta and when the Z' mass is roughly in the range 600 GeV to 1.3 TeV.

Asher Berlin; Tongyan Lin; Lian-Tao Wang

2014-02-27T23:59:59.000Z

165

Secluded WIMP Dark Matter  

E-Print Network [OSTI]

We consider a generic mechanism via which thermal relic WIMP dark matter may be decoupled from the Standard Model, namely through a combination of WIMP annihilation to metastable mediators with subsequent delayed decay to Standard Model states. We illustrate this with explicit examples of WIMPs connected to the Standard Model by metastable bosons or fermions. In all models, provided the WIMP mass is greater than that of the mediator, it can be secluded from the Standard Model with an extremely small elastic scattering cross-section on nuclei and rate for direct collider production. In contrast, indirect signatures from WIMP annihilation are consistent with a weak scale cross-section and provide potentially observable \\gamma-ray signals. We also point out that \\gamma-ray constraints and flavor physics impose severe restrictions on MeV-scale variants of secluded models, and identify limited classes that pass all the observational constraints.

Maxim Pospelov; Adam Ritz; Mikhail B. Voloshin

2007-11-30T23:59:59.000Z

166

Light Higgses and Dark Matter at Bottom and Charm Factories  

E-Print Network [OSTI]

Neither Dark Matter nor scalar particles in the Higgs sector are ruled out at energies accessible to bottom and charm factories. In Dark Matter searches, the error on the mass of Dark Matter is $\\sim 4$ GeV in the best LHC studies. For light Dark Matter this could represent a 100% (or more) error. In Higgs searches, the presence of a light singlet Higgs can make the LHC Higgs search difficult, if not impossible. If Dark Matter or a Higgs scalar is light, it will {\\it require} a low-energy machine to precisely determine the couplings. We review the models, modes of discovery and rate expectations for these new particle searches at bottom and charm factories. We also discuss the options for new runs at bottom and charm factories relevant for these searches.

Bob McElrath

2007-12-03T23:59:59.000Z

167

Photoconductivity of Si/Ge multilayer structures with Ge quantum dots pseudomorphic to the Si matrix  

SciTech Connect (OSTI)

Longitudinal photoconductivity spectra of Si/Ge multilayer structures with Ge quantum dots grown pseudomorphically to the Si matrix are studied. Lines of optical transitions between hole levels of quantum dots and Si electronic states are observed. This allowed us to construct a detailed energy-level diagram of electron-hole levels of the structure. It is shown that hole levels of pseudomorphic Ge quantum dots are well described by the simplest 'quantum box' model using actual sizes of Ge islands. The possibility of controlling the position of the long-wavelength photosensitivity edge by varying the growth parameters of Si/Ge structures with Ge quantum dots is determined.

Talochkin, A. B., E-mail: tal@thermo.isp.nsc.ru; Chistokhin, I. B. [Russian Academy of Sciences, Rzhanov Institute of Semiconductor Physics, Siberian Branch (Russian Federation)

2011-07-15T23:59:59.000Z

168

Gravitational-wave spin-down and stalling lower limits on the electrical resistivity of the accreted mountain in a millisecond pulsar  

E-Print Network [OSTI]

The electrical resistivity of the accreted mountain in a millisecond pulsar is limited by the observed spin-down rate of binary radio millisecond pulsars (BRMSPs) and the spins and X-ray fluxes of accreting millisecond pulsars (AMSPs). We find $\\eta \\ge 10^{-28}\\,\\mathrm{s}\\, (\\tau_\\mathrm{SD}/1\\,\\mathrm{Gyr})^{-0.8}$ (where $\\tau_\\mathrm{SD}$ is the spin-down age) for BRMSPs and $\\eta \\ge 10^{-25}\\,\\mathrm{s}\\,(\\dot{M}_\\mathrm{a}/\\dot{M}_\\mathrm{E})^{0.6}$ (where $\\dot{M}_\\mathrm{a}$ and $\\dot{M}_\\mathrm{E}$ are the actual and Eddington accretion rates) for AMSPs. These limits are inferred assuming that the mountain attains a steady state, where matter diffuses resistively across magnetic flux surfaces but is replenished at an equal rate by infalling material. The mountain then relaxes further resistively after accretion ceases. The BRMSP spin-down limit approaches the theoretical electron-impurity resistivity at temperatures $\\ga 10^5$ K for an impurity concentration of $\\sim 0.1$, while the AMSP stalling limit falls two orders of magnitude below the theoretical electron-phonon resistivity for temperatures above $10^8$ K. Hence BRMSP observations are already challenging theoretical resistivity calculations in a useful way. Next-generation gravitational-wave interferometers will constrain $\\eta$ at a level that will be competitive with electromagnetic observations.

Matthias Vigelius; Andrew Melatos

2010-05-13T23:59:59.000Z

169

Ge atom distribution in buried dome islands  

SciTech Connect (OSTI)

Laser-assisted atom probe tomography microscopy is used to provide direct and quantitative compositional measurements of tri-dimensional Ge distribution in Ge dome islands buried by Si. Sub-nanometer spatial resolution 3D imaging shows that islands keep their facets after deposition of the Si cap, and that the island/substrate/Si cap interfaces are abrupt. The core of the domes contains 55% of Ge, while the island shell exhibits a constant composition of 15% of Ge. The {l_brace}113{r_brace} facets of the islands present a Ge enrichment up to 35%. The wetting layer composition is not homogeneous, varying from 9.5% to 30% of Ge.

Portavoce, A.; Berbezier, I.; Ronda, A.; Mangelinck, D. [CNRS, IM2NP, Case 142, 13397 Marseille Cedex 20 (France); Hoummada, K. [Aix-Marseille Universite, IM2NP, Case 142, 13397 Marseille Cedex 20 (France)

2012-04-16T23:59:59.000Z

170

Dark matter search in a Beam-Dump eXperiment (BDX) at Jefferson Lab  

E-Print Network [OSTI]

MeV-GeV dark matter (DM) is theoretically well motivated but remarkably unexplored. This Letter of Intent presents the MeV-GeV DM discovery potential for a 1 m$^3$ segmented plastic scintillator detector placed downstream of the beam-dump at one of the high intensity JLab experimental Halls, receiving up to 10$^{22}$ electrons-on-target (EOT) in a one-year period. This experiment (Beam-Dump eXperiment or BDX) is sensitive to DM-nucleon elastic scattering at the level of a thousand counts per year, with very low threshold recoil energies ($\\sim$1 MeV), and limited only by reducible cosmogenic backgrounds. Sensitivity to DM-electron elastic scattering and/or inelastic DM would be below 10 counts per year after requiring all electromagnetic showers in the detector to exceed a few-hundred MeV, which dramatically reduces or altogether eliminates all backgrounds. Detailed Monte Carlo simulations are in progress to finalize the detector design and experimental set up. An existing 0.036 m$^3$ prototype based on the s...

Battaglieri, M; De Vita, R; Izaguirre, E; Krnjaic, G; Smith, E; Stepanyan, S; Bersani, A; Fanchini, E; Fegan, S; Musico, P; Osipenko, M; Ripani, M; Santopinto, E; Taiuti, M; Schuster, P; Toro, N; Dalton, M; Freyberger, A; Girod, F -X; Kubarovsky, V; Ungaro, M; De Cataldo, G; De Leo, R; Di Bari, D; Lagamba, L; Nappi, E; Perrino, R; Carpinelli, M; Sipala, V; Aiello, S; Bellini, V; De Napoli, M; Giusa, A; Mammoliti, F; Leonora, E; Noto, F; Randazzo, N; Russo, G; Sperduto, M; Sutera, C; Ventura, C; Barion, L; Ciullo, G; Contalbrigo, M; Lenisa, P; Movsisyan, A; Spizzo, F; Turisini, M; De Persio, F; Cisbani, E; Fanelli, C; Garibaldi, F; Meddi, F; Urciuoli, G M; Pereira, S Anefalos; De Sanctis, E; Hasch, D; Lucherini, V; Mirazita, M; Montgomery, R; Pisano, S; Simi, G; D'Angelo, A; Lanza, L Colaneri L; Rizzo, A; Schaerf, C; Zonta, I; Calvo, D; Filippi, A; Holtrop, M; Peremuzyan, R; Glazier, D; Ireland, D; McKinnon, B; Afanasev, D Sokhan A; Briscoe, B; Kalantarians, N; Fassi, L El; Weinstein, L; Beltrame, P; Murphy, A; Watts, D; Zana, L; Hicks, K

2014-01-01T23:59:59.000Z

171

Observing Higgs boson production through its decay into ?-rays: A messenger for dark matter candidates  

Science Journals Connector (OSTI)

Abstract In this Letter, we study the ?-ray signatures subsequent to the production of a Higgs boson in space by dark matter annihilations. We investigate the cases where the Higgs boson is produced at rest or slightly boosted and show that such configurations can produce characteristic bumps in the ?-ray data. These results are relevant in the case of the Standard Model-like Higgs boson provided that the dark matter mass is about 63 GeV, 109 GeV or 126 GeV, but can be generalized to any other Higgs boson masses. Here, we point out that it may be worth looking for a 63 GeV line since it could be the signature of the decay of a Standard Model-like Higgs boson produced in space, as in the case of a di-Higgs final state if m ? ? 126 GeV . We show that one can set generic constraints on the Higgs boson production rates using its decay properties. In particular, using the Fermi-LAT data from the galactic center, we find that the dark matter annihilation cross section into ?+ a Standard Model-like Higgs boson produced at rest or near rest cannot exceed ? ? v ? ? a few 10 ? 25 cm 3 / s or ? ? v ? ? a few 10 ? 27 cm 3 / s respectively, providing us with information on the Higgs coupling to the dark matter particle. We conclude that Higgs bosons can indeed be used as messengers to explore the dark matter mass range.

Nicols Bernal; Cline Bhm; Sergio Palomares-Ruiz; Joseph Silk; Takashi Toma

2013-01-01T23:59:59.000Z

172

Inclusive photoproduction of strange baryons at 20 GeV  

Science Journals Connector (OSTI)

Cross sections are presented for the inclusive photoproduction of KS0, ?, ?, ?-, ? -, ?0, and ?*(1385) at 20 GeV. An upper limit to ?- production is also given. The data come from 284 000 hadronic events photoproduced in the SLAC 1-m hydrogen-bubble-chamber hybrid facility exposed to a nearly monochromatic, polarized 20-GeV backscattered photon beam. A comparison of the KS0, ?, ?, and ?- rates per inelastic event to ?p data show that ?p rates are consistent with being higher than the ?p rates, providing evidence of an ss component of the photon. The pair cross sections for KS0KS0, KS0?, KSo?, and ?? are presented. The xF distributions of the ?, ?, and ?- are compared to a quark-diquark fusion model, giving information on strange-baryon photoproduction mechanisms.

K. Abe et al.

1985-12-01T23:59:59.000Z

173

membrane-ge | netl.doe.gov  

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

High-Performance Thin Film Composite Hollow Fiber Membranes for Post-Combustion Carbon Dioxide Capture Project No.: DE-FE0007514 GE Global Research is developing high...

174

Robotic Wind Turbine Inspection | GE Global Research  

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

Trials GE Global Research is advancing technology that will make the inspection of wind turbines faster and more reliable for customers. Currently, an inspector examines the...

175

Advanced Propulsion Systems | GE Global Research  

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

primusenginefeaturedimage3 GE Innovation and Manufacturing in Europe 2-7-7-v-laser-additive-manufacturing Revolutionizing the Age-Old Rules of Manufacturing ...

176

One Young World Summit |GE Global Research  

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

photo of Valentina Bisio. About the Author Valentina Bisio EEDP Graduate GE O&G - Turbomachinery Solutions Valentina is an EEDP graduate. She completed job rotations in TMS...

177

Nanoscale Material Properties | GE Global Research  

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

Nanotechnology Drives New Levels of Performance Nanotechnology Drives New Levels of Performance GE scientists are discovering new material properties at the nanoscale that drive...

178

Happy Pi Day! | GE Global Research  

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

is an area where GE researchers are intensifying their efforts. 3-D printing, an area of additive manufacturing, is providing new manufacturing freedom that was not possible with...

179

Patricia C. Irwin | Inventors | GE Global Research  

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

50 years as they seem now." -Patricia Irwin Creating a nonradioactive tracer for use in nuclear turbine testing. Re-establishing the dielectrics team to support GE businesses....

180

Ge/SiGe quantum well devices for light modulation, detection, and emission.  

E-Print Network [OSTI]

??This PhD thesis is devoted to study electro-optic properties of Gemanium/Silicon-Germanium (Ge/SiGe) multiple quantum wells (MQWs) for light modulation, detection, and emission on Si platform. (more)

Chaisakul, Papichaya

2012-01-01T23:59:59.000Z

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


181

GeSiO phase separation and Ge nanocrystal growth in  

Science Journals Connector (OSTI)

Ge:SiOx/SiO2 multilayers are fabricated using a new reactive dc magnetron sputtering approach. The influence of the multilayer stoichiometry on the ternary GeSiO phase separation and the subsequent size-controlled Ge nanocrystal formation is explored by means of x-ray absorption spectroscopy, x-ray diffraction, electron microscopy and Raman spectroscopy. The ternary system GeSiO reveals complete GeO phase separation at 400?C which does not differ significantly to the binary GeO system. Ge nanocrystals of 2 is present after annealing. Thus, the Ge nanocrystals become completely embedded in a stoichiometric silica matrix favouring the use for photovoltaic applications.

Manuel Zschintzsch; Christoph J Sahle; Johannes von Borany; Christian Sternemann; Arndt Mcklich; Alexander Nyrow; Alexander Schwamberger; Metin Tolan

2011-01-01T23:59:59.000Z

182

Hot Hole Effects in Strained Mqw Heterostructures Ge/Ge1?xSix  

Science Journals Connector (OSTI)

The paper deals with the first investigations of the 2D hot hole effects in multilayer heterostructures Ge/Ge1?xSix...aimed at the realization of dynamical heating and intraband population inversion of carriers i...

V. Ya. Aleshkin; A. A. Andronov; N. A. Bekin

1996-01-01T23:59:59.000Z

183

Surface Properties and Collective Modes of Electron-Hole Droplets in Ge, Si and Strained Ge  

Science Journals Connector (OSTI)

The surface structure, surface energy, and dipole barrier are obtained for condensed electron-hole droplets in Ge, Si, and strained Ge at zero temperature. The surface tension is...

T. L. Reinecke; F. Crowne; S. C. Ying

1974-01-01T23:59:59.000Z

184

New Directions in Direct Dark Matter Searches  

E-Print Network [OSTI]

I present the status of direct dark matter detection with specific attention to the experimental results and their phenomenological interpretation in terms of dark matter interactions. In particular I review a new and more general approach to study signals in this field based on non-relativistic operators which parametrize more efficiently the dark matter-nucleus interactions in terms of a very limited number of relevant degrees of freedom. Then I list the major experimental results, pointing out the main uncertainties that affect the theoretical interpretation of the data. Finally, since the underlying theory that describes both the dark matter and the standard model fields is unknown, I address the uncertainties coming from the nature of the interaction. In particular, the phenomenology of a class of models in which the interaction between dark matter particles and target nuclei is of a long-range type is discussed.

Paolo Panci

2014-02-06T23:59:59.000Z

185

PSH-12-0083 - In the Matter of In the Matter of Personnel Security Hearing  

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

83 - In the Matter of In the Matter of Personnel Security 83 - In the Matter of In the Matter of Personnel Security Hearing PSH-12-0083 - In the Matter of In the Matter of Personnel Security Hearing On November 14, 2012, an OHA Hearing Officer issued a decision in which he concluded that an individual's security clearance should be restored. A Local Security Office suspended the individual's security clearance for failing to comply with rules regarding the handling of classified information and conduct within limited access areas and for failing to report such non-compliance. This behavior raised security concerns under Criteria G and L. After conducting a hearing and evaluating the documentary and testimonial evidence, the Hearing Officer found that the individual had presented sufficient evidence to resolve these security

186

Recent Developments in Supersymmetric and Hidden Sector Dark Matter  

SciTech Connect (OSTI)

New results which correlate SUSY dark matter with LHC signals are presented, and a brief review of recent developments in supersymmetric and hidden sector dark matter is given. It is shown that the direct detection of dark matter is very sensitive to the hierarchical SUSY sparticle spectrum and the spectrum is very useful in distinguishing models. It is shown that the prospects of the discovery of neutralino dark matter are very bright on the 'Chargino Wall' due to a copious number of model points on the Wall, where the NLSP is the Chargino, and the spin independent neutralino-proton cross section is maintained at high values in the 10{sup -44} cm{sup 2} range for neutralino masses up to {approx}850 GeV. It is also shown that the direct detection of dark matter along with lepton plus jet signatures and missing energy provide dual, and often complementary, probes of supersymmetry. Finally, we discuss an out of the box possibility for dark matter, which includes dark matter from the hidden sector, which could either consist of extra weakly interacting dark matter (a Stino XWIMP), or milli-charged dark matter arising from the Stueckelberg extensions of the MSSM or the SM.

Feldman, Daniel; Liu Zuowei [Department of Physics, Northeastern University, Boston, MA 02115 (United States); Nath, Pran [Department of Physics, Northeastern University, Boston, MA 02115 (United States); TH Division, PH Department, CERN, CH-1211 Geneva 23 (Switzerland)

2008-11-23T23:59:59.000Z

187

Recent Developments in Supersymmetric and Hidden Sector Dark Matter  

E-Print Network [OSTI]

New results which correlate SUSY dark matter with LHC signals are presented, and a brief review of recent developments in supersymmetric and hidden sector dark matter is given. It is shown that the direct detection of dark matter is very sensitive to the hierarchical SUSY sparticle spectrum and the spectrum is very useful in distinguishing models. It is shown that the prospects of the discovery of neutralino dark matter are very bright on the "Chargino Wall" due to a copious number of model points on the Wall, where the NLSP is the Chargino, and the spin independent neutralino-proton cross section is maintained at high values in the $10^{-44}$cm$^{2}$ range for neutralino masses up to $\\sim 850$ GeV . It is also shown that the direct detection of dark matter along with lepton plus jet signatures and missing energy provide dual, and often complementary, probes of supersymmetry. Finally, we discuss an out of the box possibility for dark matter, which includes dark matter from the hidden sector, which could either consist of extra weakly interacting dark matter (a Stino XWIMP), or milli-charged dark matter arising from the Stueckelberg extensions of the MSSM or the SM.

Daniel Feldman; Zuowei Liu; Pran Nath

2008-06-29T23:59:59.000Z

188

Structure and magnetism in strained Ge{sub 1-x-y}Sn{sub x}Mn{sub y} films grown on Ge(001) by low temperature molecular beam epitaxy  

SciTech Connect (OSTI)

In this letter, we study the structural and magnetic properties of Ge{sub 1-x-y}Sn{sub x}Mn{sub y} films grown on Ge(001) by low temperature molecular beam epitaxy using X-ray diffraction, high resolution transmission electron microscopy, and superconducting quantum interference device. Like in Mn doped Ge films, Mn atoms diffuse during the growth and aggregate into vertically aligned Mn-rich nanocolumns of a few nanometers in diameter. Transmission electron microscopy observations in plane view clearly indicate that the Sn incorporation is not uniform with concentration in Mn rich vertical nanocolumns lower than the detection limit of electron energy loss spectroscopy. The matrix exhibits a GeSn solid solution while there is a Sn-rich GeSn shell around GeMn nanocolumns. The magnetization in Ge{sub 1-x-y}Sn{sub x}Mn{sub y} layers is higher than in Ge{sub 1-x}Mn{sub x} films. This magnetic moment enhancement in Ge{sub 1-x-y}Sn{sub x}Mn{sub y} is probably related to the modification of the electronic structure of Mn atoms in the nanocolumns by the Sn-rich shell, which is formed around the nanocolumns.

Prestat, E. [INAC, SP2M, CEA and Universite Joseph Fourier, 17 rue des Martyrs, 38054 Grenoble (France); Karlsruher Institut fuer Technologie (KIT), Laboratorium fuer Elektronenmikroskopie, D-76128 Karlsruhe (Germany); Barski, A.; Bellet-Amalric, E.; Morel, R.; Tainoff, D.; Jain, A.; Porret, C.; Bayle-Guillemaud, P.; Jamet, M. [INAC, SP2M, CEA and Universite Joseph Fourier, 17 rue des Martyrs, 38054 Grenoble (France); Jacquot, J.-F. [INAC, SCIB, CEA and Universite Joseph Fourier, 17 rue des Martyrs, 38054 Grenoble (France)

2013-07-01T23:59:59.000Z

189

Dark matter search in a Beam-Dump eXperiment (BDX) at Jefferson Lab  

E-Print Network [OSTI]

MeV-GeV dark matter (DM) is theoretically well motivated but remarkably unexplored. This Letter of Intent presents the MeV-GeV DM discovery potential for a 1 m$^3$ segmented plastic scintillator detector placed downstream of the beam-dump at one of the high intensity JLab experimental Halls, receiving up to 10$^{22}$ electrons-on-target (EOT) in a one-year period. This experiment (Beam-Dump eXperiment or BDX) is sensitive to DM-nucleon elastic scattering at the level of a thousand counts per year, with very low threshold recoil energies ($\\sim$1 MeV), and limited only by reducible cosmogenic backgrounds. Sensitivity to DM-electron elastic scattering and/or inelastic DM would be below 10 counts per year after requiring all electromagnetic showers in the detector to exceed a few-hundred MeV, which dramatically reduces or altogether eliminates all backgrounds. Detailed Monte Carlo simulations are in progress to finalize the detector design and experimental set up. An existing 0.036 m$^3$ prototype based on the same technology will be used to validate simulations with background rate estimates, driving the necessary R$\\&$D towards an optimized detector. The final detector design and experimental set up will be presented in a full proposal to be submitted to the next JLab PAC. A fully realized experiment would be sensitive to large regions of DM parameter space, exceeding the discovery potential of existing and planned experiments by two orders of magnitude in the MeV-GeV DM mass range.

BDX Collaboration; M. Battaglieri; A. Celentano; R. De Vita; E. Izaguirre; G. Krnjaic; E. Smith; S. Stepanyan; A. Bersani; E. Fanchini; S. Fegan; P. Musico; M. Osipenko; M. Ripani; E. Santopinto; M. Taiuti; P. Schuster; N. Toro; M. Dalton; A. Freyberger; F. -X. Girod; V. Kubarovsky; M. Ungaro; G. De Cataldo; R. De Leo; D. Di Bari; L. Lagamba; E. Nappi; R. Perrino; M. Carpinelli; V. Sipala; S. Aiello; V. Bellini; M. De Napoli; A. Giusa; F. Mammoliti; E. Leonora; F. Noto; N. Randazzo; G. Russo; M. Sperduto; C. Sutera; C. Ventura; L. Barion; G. Ciullo; M. Contalbrigo; P. Lenisa; A. Movsisyan; F. Spizzo; M. Turisini; F. De Persio; E. Cisbani; C. Fanelli; F. Garibaldi; F. Meddi; G. M. Urciuoli; S. Anefalos Pereira; E. De Sanctis; D. Hasch; V. Lucherini; M. Mirazita; R. Montgomery; S. Pisano; G. Simi; A. D'Angelo; L. Colaneri L. Lanza; A. Rizzo; C. Schaerf; I. Zonta; D. Calvo; A. Filippi; M. Holtrop; R. Peremuzyan; D. Glazier; D. Ireland; B. McKinnon; D. Sokhan A. Afanasev; B. Briscoe; N. Kalantarians; L. El Fassi; L. Weinstein; P. Beltrame; A. Murphy; D. Watts; L. Zana; K. Hicks

2014-06-11T23:59:59.000Z

190

Using effective operators to understand CoGeNT and CDMS-Si signals  

Science Journals Connector (OSTI)

Several direct detection experiments have reported positive signals consistent with a dark matter particle with a mass of approximately 79GeV and a spin-independent scattering cross section of 2.54.810-41??cm2. These results do not rise to the level of discovery, but assuming that they are due to dark matter, some questions about the underlying physics can already be addressed. In this paper, I apply the effective operator formalism for dark matter Standard Model interactions to the results of the CoGeNT and CDMS silicon target experiments. I demonstrate that only one set of flavor-blind effective operators between dark matter and quarks can be consistent with the reported results in all energy regimes of interest, namely thermal freeze-out, nuclear scattering, indirect detection, and TeV-scale colliders. This set of operators implies large couplings of dark matter with heavy quarks. The alternative implies either that the new physics has nontrivial flavor structure, that the effective formalism is not applicable and so contains new states in the spectrum accessible at the LHC, or has large annihilation channels (possibly via effective operators) into noncolored Standard Model particles.

Matthew R. Buckley

2013-09-30T23:59:59.000Z

191

The first cryogenic dark matter experiment  

SciTech Connect (OSTI)

An experimental search for dark matter particle candidates using cryogenic detectors requires a low radioactive background environment. The authors discuss the status of a cryogenic dark matter experiment to be performed in the Stanford Underground Facility. The detectors will be cooled in a specially designed cryostat connected to a modified side access Oxford 400 dilution refrigerator. Details of the cryostat design and its operating performance are presented. The effectiveness of the multi-level shield surrounding the cryostat, as well as the background levels expected to be achieved in the pilot experiment are discussed. Finally, the limits which can be set on dark matter candidates with such an experiment are discussed.

Barnes, P.D.; Aubourg, E.; Akerib, D.S.; Cummings, A.; Lange, A.E.; Margulies, S.; Sadoulet, B.; Shutt, T.; Stockwell, W.; White, S.; Young, B.A. (Univ. of California, Berkeley, CA (United States)); Da Silva, A. (Univ. of British Columbia, BC (Canada)); Bauer, D.; Borden, D.; Caldwell, D.O.; Gray, M.; Hale, D.; Lu, A.; Witherell, M.; Yellin, S. (Univ. of California, Santa Barbara, CA (United States)); Cabrera, B.; Chugg, B.; Dougherty, B.L.; Irwin, K.D.; Penn, M.J. (Stanford Univ., Stanford, CA (United States)); Emes, J.; Smith, A.; Smith, G.; Taylor, J.; Wolgast, C.; Haller, E.E. (Lawrence Berkeley Lab., CA (United States)); Pritychenko, B.V.; Pomansky, A.A. (Institute for Nuclear Research, Moscow (Russian Federation)); Ross, R.R. (Univ. of California, Berkeley, CA (United States) Lawrence Berkeley Lab., CA (United States))

1993-11-01T23:59:59.000Z

192

RHIC | Why Does Quark Matter Matter?  

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

Why Does Quark Matter 'Matter'? Why Does Quark Matter 'Matter'? The history of modern technological development can be viewed as a series of investigations, with ever increasing resolution, into the microscopic structure of matter. Since the days of the early Greek philosophers, science has been on a continual quest to find the smallest piece - the most fundamental building block - forming the substance of the universe. STAR researchers During that journey, many beautiful and exotic properties of the subatomic world have been discovered: particles with wave-like properties the ultimate position of which can never be known; "particles" of light that deliver a fixed amount of energy when they strike the atoms of a material's surface; particles in some types of electrical conductors that

193

EXC-12-0001, EXC-12-0002, EXC-12-0003 - In the Matter of Philips Lighting  

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

1, EXC-12-0002, EXC-12-0003 - In the Matter of Philips 1, EXC-12-0002, EXC-12-0003 - In the Matter of Philips Lighting Company, GE Lighting, and OSRAM SYLVANIA, Inc. EXC-12-0001, EXC-12-0002, EXC-12-0003 - In the Matter of Philips Lighting Company, GE Lighting, and OSRAM SYLVANIA, Inc. On April 16, 2012, OHA issued a decision granting Applications for Exception filed respectively by Philips Lighting Company (Philips), GE Lighting (GE) and OSRAM SYLVANIA, Inc. (OSI) (collectively, "the Applicants"), for relief from the provisions of 10 C.F.R. Part 430, Energy Conservation Program: Energy Conservation Standards and Test Procedures for General Service Fluorescent Lamps and Incandescent Reflector Lamps (Lighting Efficiency Standards). In their exception requests, the Applicants asserted that they will suffer a serious hardship, gross

194

EXC-12-0001, EXC-12-0002, EXC-12-0003 - In the Matter of Philips Lighting  

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

EXC-12-0001, EXC-12-0002, EXC-12-0003 - In the Matter of Philips EXC-12-0001, EXC-12-0002, EXC-12-0003 - In the Matter of Philips Lighting Company, GE Lighting, and OSRAM SYLVANIA, Inc. EXC-12-0001, EXC-12-0002, EXC-12-0003 - In the Matter of Philips Lighting Company, GE Lighting, and OSRAM SYLVANIA, Inc. On April 16, 2012, OHA issued a decision granting Applications for Exception filed respectively by Philips Lighting Company (Philips), GE Lighting (GE) and OSRAM SYLVANIA, Inc. (OSI) (collectively, "the Applicants"), for relief from the provisions of 10 C.F.R. Part 430, Energy Conservation Program: Energy Conservation Standards and Test Procedures for General Service Fluorescent Lamps and Incandescent Reflector Lamps (Lighting Efficiency Standards). In their exception requests, the Applicants asserted that they will suffer a serious hardship, gross

195

GE Turbine Parts www.edisonmachine.com  

E-Print Network [OSTI]

vehicle: Has the code for a hydrogen car been cracked? World-first working eukaryotic cell mad from get swanky with the Equus Bass770 Zenos reveals details of the E10 roadster The Toyota FCV fuel cellGE Turbine Parts www.edisonmachine.com New authentic GE and Westinghouse Turbine Parts Muscle cars

Chiao, Jung-Chih

196

Modeling of GE Appliances: Final Presentation  

SciTech Connect (OSTI)

This report is the final in a series of three reports funded by U.S. Department of Energy Office of Electricity Delivery and Energy Reliability (DOE-OE) in collaboration with GE Appliances through a Cooperative Research and Development Agreement (CRADA) to describe the potential of GE Appliances DR-enabled appliances to provide benefits to the utility grid.

Fuller, Jason C.; Vyakaranam, Bharat; Leistritz, Sean M.; Parker, Graham B.

2013-01-31T23:59:59.000Z

197

Axion dark matter detection with cold molecules  

Science Journals Connector (OSTI)

Current techniques cannot detect axion dark matter over much of its parameter space, particularly in the theoretically well-motivated region where the axion decay constant fa lies near the grand unified theory (GUT) and Planck scales. We suggest a novel experimental method to search for QCD axion dark matter in this region. The axion field oscillates at a frequency equal to its mass when it is a component of dark matter. These oscillations induce time varying CP-odd nuclear moments, such as electric dipole and Schiff moments. The coupling between internal atomic fields and these nuclear moments gives rise to time varying shifts to atomic energy levels. These effects can be enhanced by using elements with large Schiff moments such as the light Actinides, and states with large spontaneous parity violation, such as molecules in a background electric field. The energy level shift in such a molecule can be ?10-24??eV or larger. While challenging, this energy shift may be observable in a molecular clock configuration with technology presently under development. The detectability of this energy shift is enhanced by the fact that it is a time varying shift whose oscillation frequency is set by fundamental physics, and is therefore independent of the details of the experiment. This signal is most easily observed in the sub-MHz range, allowing detection when fa is ?1016??GeV, and possibly as low as 1015??GeV. A discovery in such an experiment would not only reveal the nature of dark matter and confirm the axion as the solution to the strong CP problem, it would also provide a glimpse of physics at the highest energy scales, far beyond what can be directly probed in the laboratory.

Peter W. Graham and Surjeet Rajendran

2011-09-15T23:59:59.000Z

198

Dark matter and the solar neutrino problem: Can particle physics provide a single solution  

SciTech Connect (OSTI)

We show how a relatively simple extension of the standard model can give a natural'' explanation for both the solar neutrino and dark matter problems. What is required is a new stable neutral lepton with a mass in the 4--8 GeV range. One possibility is a fourth generation neutrino interacting with matter either electromagnetically or via higgs-exchange (in addition, of course, to Z{degree}-exchange). In the former case, a new charged lepton with mass {approximately}10GeV would be required in order to generate a sufficiently large magnetic moment. The present experimental situation makes this possibility rather doubtful. In the latter case, a light higgs with mass {approximately}1GeV is required; this is still not ruled out experimentally. In any case, direct (or indirect) detection of dark matter will, during the next year, seal the fate of this model. 29 refs.

West, G.B. (Los Alamos National Lab., NM (USA))

1989-01-01T23:59:59.000Z

199

Likelihood approach to the first dark matter results from XENON100  

Science Journals Connector (OSTI)

Many experiments that aim at the direct detection of dark matter are able to distinguish a dominant background from the expected feeble signals, based on some measured discrimination parameter. We develop a statistical model for such experiments using the profile likelihood ratio as a test statistic in a frequentist approach. We take data from calibrations as control measurements for signal and background, and the method allows the inclusion of data from MonteCarlo simulations. Systematic detector uncertainties, such as uncertainties in the energy scale, as well as astrophysical uncertainties, are included in the model. The statistical model can be used to either set an exclusion limit or to quantify a discovery claim, and the results are derived with the proper treatment of statistical and systematic uncertainties. We apply the model to the first data release of the XENON100 experiment, which allows one to extract additional information from the data, and place stronger limits on the spin-independent elastic weakly interacting massive particles nucleon scattering cross section. In particular, we derive a single limit, including all relevant systematic uncertainties, with a minimum of 2.410-44??cm2 for weakly interacting massive particles with a mass of 50??GeV/c2.

E. Aprile et al. (XENON100 Collaboration)

2011-09-07T23:59:59.000Z

200

in Condensed Matter Physics  

E-Print Network [OSTI]

Master in Condensed Matter Physics ­ Master académique #12;2 #12;3 Students at the University. Condensed matter physics is about explaining and predicting the relationship between the atomic, and broad education in the field of condensed matter physics · introduce you to current research topics

van der Torre, Leon

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


201

Growth and characterization of isotopically enriched {sup 70}Ge and {sup 74}Ge single crystals  

SciTech Connect (OSTI)

Isotopically enriched {sup 70}Ge and {sup 74}Ge single crystals were successfully gown by a newly developed vertical Bridgman method. The system allows us to reliably grow high purity Ge single crystals of approximately 1 cm{sup 3} volume. To our knowledge, we have grown the first {sup 70}Ge single crystal. The electrically active chemical impurity concentration for both crystals was found to be {approximately}2 {times} cm{sup {minus}3} which is two order of magnitude better that of {sup 74}Ge crystals previously grown by two different groups. Isotopic enrichment of the {sup 70}Ge and the {sup 74}Ge crystals is 96.3% and 96.8%, respectively. The residual chemical impurities present in both crystals were identified as phosphorus, copper, aluminum, and indium. A wide variety of experiments which take advantage of the isotopic purity of our crystals are discussed.

Itoh, K.

1992-10-01T23:59:59.000Z

202

Growth and characterization of isotopically enriched [sup 70]Ge and [sup 74]Ge single crystals  

SciTech Connect (OSTI)

Isotopically enriched [sup 70]Ge and [sup 74]Ge single crystals were successfully gown by a newly developed vertical Bridgman method. The system allows us to reliably grow high purity Ge single crystals of approximately 1 cm[sup 3] volume. To our knowledge, we have grown the first [sup 70]Ge single crystal. The electrically active chemical impurity concentration for both crystals was found to be [approximately]2 [times] cm[sup [minus]3] which is two order of magnitude better that of [sup 74]Ge crystals previously grown by two different groups. Isotopic enrichment of the [sup 70]Ge and the [sup 74]Ge crystals is 96.3% and 96.8%, respectively. The residual chemical impurities present in both crystals were identified as phosphorus, copper, aluminum, and indium. A wide variety of experiments which take advantage of the isotopic purity of our crystals are discussed.

Itoh, K.

1992-10-01T23:59:59.000Z

203

Pseudomorphic GeSn/Ge(001) quantum wells: Examining indirect band gap bowing  

SciTech Connect (OSTI)

A study of the bandgap character of compressively strained GeSn{sub 0.060-0.091}/Ge(001) quantum wells grown by molecular beam epitaxy is reported. The built-in strain in GeSn wells leads to an increased separation between L and {Gamma} conduction band minima. The prevalent indirect interband transitions in GeSn were probed by photoluminescence spectroscopy. As a result we could simulate the L-valley bowing parameter in GeSn alloys, b{sub L} = 0.80 {+-} 0.06 eV at 10 K. From this we conclude that even compressively strained GeSn/Ge(001) alloys could become direct band gap semiconductors at the Sn-fraction higher than 17.0 at. %.

Tonkikh, Alexander A. [Max Planck Institute of Microstructure Physics, Weinberg 2 D-06120, Halle (Saale) (Germany); Institute for Physics of Microstructures RAS, GSP-105, Nizhniy Novgorod (Russian Federation); Eisenschmidt, Christian; Schmidt, Georg [Institute of Physics, Martin Luther University Halle-Wittenberg, Von-Danckelmann-Platz 3 D-01620, Halle (Saale) (Germany); Talalaev, Vadim G. [Max Planck Institute of Microstructure Physics, Weinberg 2 D-06120, Halle (Saale) (Germany); ZIK SiLi-Nano, Martin Luther University Halle-Wittenberg, Karl-Freiherr-von-Fritsch-Str. 3 D-06120, Halle (Saale) (Germany); Zakharov, Nikolay D.; Werner, Peter [Max Planck Institute of Microstructure Physics, Weinberg 2 D-06120, Halle (Saale) (Germany); Schilling, Joerg [ZIK SiLi-Nano, Martin Luther University Halle-Wittenberg, Karl-Freiherr-von-Fritsch-Str. 3 D-06120, Halle (Saale) (Germany)

2013-07-15T23:59:59.000Z

204

Ge-on-Si laser for silicon photonics  

E-Print Network [OSTI]

Ge-on-Si devices are explored for photonic integration. Importance of Ge in photonics has grown and through techniques developed in our group we demonstrated low density of dislocations (<1x109cm-2) and point defects Ge ...

Camacho-Aguilera, Rodolfo Ernesto

2013-01-01T23:59:59.000Z

205

Science as Art: Jet Engine Airflow | GE Global Research  

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

used heavily by GE Aviation, GE Power & Water, and GE Oil & Gas for the design of turbomachinery, e.g. jet engines, gas turbines, etc. I had the chance to talk with Brian to...

206

CMB constraints on light dark matter candidates  

E-Print Network [OSTI]

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

Evoli, Carmelo; Ferrara, Andrea

2012-01-01T23:59:59.000Z

207

Big Questions: Dark Matter  

ScienceCinema (OSTI)

Carl Sagan's oft-quoted statement that there are "billions and billions" of stars in the cosmos gives an idea of just how much "stuff" is in the universe. However scientists now think that in addition to the type of matter with which we are familiar, there is another kind of matter out there. This new kind of matter is called "dark matter" and there seems to be five times as much as ordinary matter. Dark matter interacts only with gravity, thus light simply zips right by it. Scientists are searching through their data, trying to prove that the dark matter idea is real. Fermilab's Dr. Don Lincoln tells us why we think this seemingly-crazy idea might not be so crazy after all.

Lincoln, Don

2014-08-07T23:59:59.000Z

208

Engineer Receives UMass "Salute To Service" Award | GE Global...  

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

GE Engineer Honored by Alma Mater With Prestigious UMass "Salute To Service" Award GE Engineer Honored by Alma Mater With Prestigious UMass "Salute To Service" Award Dr. Marshall...

209

Magnetic X-Ray Scattering Study of GdCo2Ge2 and NdCo2Ge2  

SciTech Connect (OSTI)

The results of magnetic x-ray resonant exchange scattering (XRES) experiments are important to the development of an understanding of magnetic interactions in materials. The advantages of high Q resolution, polarization analysis, and the ability to study many different types of materials make it a vital tool in the field of condensed matter physics. Though the concept of XRES was put forth by Platzman and Tzoar in 1970, the technique did not gain much attention until the work of Gibbs and McWhan et al. in 1988. Since then, the technique of XRES has grown immensely in use and applicability. Researchers continue to improve upon the procedure and detection capabilities in order to study magnetic materials of all kinds. The XRES technique is particularly well suited to studying the rare earth metals because of the energy range involved. The resonant L edges of these elements fall between 5-10 KeV. Resonant and nonresonant x-ray scattering experiments were performed in order to develop an understanding of the magnetic ordering in GdCo{sub 2}Ge{sub 2} and NdCo{sub 2}Ge{sub 2}.

William Good

2002-08-27T23:59:59.000Z

210

Deviations from ideal nucleation-limited relaxation in high-Ge content compositionally graded SiGe/Si*  

E-Print Network [OSTI]

and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139 such as lasers,12,13 waveguides,14 and high- efficiency solar cells.15,16 In this system, scalable x Si1-xGex /Si

211

Energy band alignment of atomic layer deposited HfO{sub 2} oxide film on epitaxial (100)Ge, (110)Ge, and (111)Ge layers  

SciTech Connect (OSTI)

Crystallographically oriented epitaxial Ge layers were grown on (100), (110), and (111)A GaAs substrates by in situ growth process using two separate molecular beam epitaxy chambers. The band alignment properties of atomic layer hafnium oxide (HfO{sub 2}) film deposited on crystallographically oriented epitaxial Ge were investigated using x-ray photoelectron spectroscopy (XPS). Valence band offset, {Delta}E{sub v} values of HfO{sub 2} relative to (100)Ge, (110)Ge, and (111)Ge orientations were 2.8 eV, 2.28 eV, and 2.5 eV, respectively. Using XPS data, variation in valence band offset, {Delta}E{sub V}(100)Ge>{Delta}E{sub V}(111)Ge>{Delta}E{sub V}(110)Ge, was obtained related to Ge orientation. Also, the conduction band offset, {Delta}E{sub c} relation, {Delta}E{sub c}(110)Ge>{Delta}E{sub c}(111)Ge>{Delta}E{sub c}(100)Ge related to Ge orientations was obtained using the measured bandgap of HfO{sub 2} on each orientation and with the Ge bandgap of 0.67 eV. These band offset parameters for carrier confinement would offer an important guidance to design Ge-based p- and n-channel metal-oxide field-effect transistor for low-power application.

Hudait, Mantu K.; Zhu Yan [Advanced Devices and Sustainable Energy Laboratory (ADSEL), Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States)

2013-03-21T23:59:59.000Z

212

26. 1% solar cell efficiency for Ge mechanically stacked under GaAs  

SciTech Connect (OSTI)

We have processed a diffused Ge wafer into a Ge concentrator solar cell and mechanically stacked it under a GaAs cell fabricated by Varian. We measured this stack's efficiency to be 26.1% for terrestrial air mass 1.5 direct (AM1.5D) conditions at a 285 x concentration ratio. We showed that this efficiency is limited by optical absorption in the Varian GaAs cell caused by high 2--4 (10/sup 18/) cm/sup -3/ substrate doping. We used a 2 x 10/sup 17/ cm/sup -3/ doped GaAs filter to estimate the stack efficiency as 27.4%, which would be achieved with the same Varian GaAs cell formed on a lower doped substrate. We project efficiencies assuming the best properties reported for a GaAs device. This gives a 29.6% efficiency for an improved, planar Ge cell and 31.6% efficiency for a proposed point contact geometry for the Ge cell. The corresponding space (AM0) efficiencies at a 159 x concentration ratio range from the 23.4% value we measured on the stack up to 28.4% projected for the point contact Ge place under the best GaAs cell. We showed that Ge cells give higher efficiencies than Si when stacked under GaAs.

Partain, L.D.; Kuryla, M.S.; Weiss, R.E.; Ransom, R.A.; McLeod, P.S.; Fraas, L.M.; Cape, J.A.

1987-10-01T23:59:59.000Z

213

Radio and gamma-ray constraints on dark matter annihilation in the Galactic center  

SciTech Connect (OSTI)

We determine upper limits on the dark matter (DM) self-annihilation cross section for scenarios in which annihilation leads to the production of electron--positron pairs. In the Galactic center, relativistic electrons and positrons produce a radio flux via synchroton emission, and a gamma-ray flux via bremsstrahlung and inverse Compton scattering. On the basis of archival, interferometric and single-dish radio data, we have determined the radio spectrum of an elliptical region around the Galactic center of extent 3 deg. semimajor axis (along the Galactic plane) and 1 deg. semiminor axis and a second, rectangular region, also centered on the Galactic center, of extent 1.6 deg. x 0.6 deg. The radio spectra of both regions are nonthermal over the range of frequencies for which we have data: 74 MHz-10 GHz. We also consider gamma-ray data covering the same region from the EGRET instrument (about GeV) and from HESS (around TeV). We show how the combination of these data can be used to place robust constraints on DM annihilation scenarios, in a way which is relatively insensitive to assumptions about the magnetic field amplitude in this region. Our results are approximately an order of magnitude more constraining than existing Galactic center radio and gamma-ray limits. For a DM mass of m{sub {chi}=}10 GeV, and an Navarro-Frank-White profile, we find <{sigma}{sub A}v>{<=}fewx10{sup -25} cm{sup 3} s{sup -1}.

Crocker, R. M. [School of Physics, University of Melbourne, 3010, Victoria (Australia); School of Physics, Monash University, 3800, Victoria (Australia); Max Planck Institut fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany); Bell, N. F. [School of Physics, University of Melbourne, 3010, Victoria (Australia); Balazs, C. [School of Physics, Monash University, 3800, Victoria (Australia); Jones, D. I. [Max Planck Institut fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany)

2010-03-15T23:59:59.000Z

214

Empirical Formula for Pion Production in Proton-Proton Collisions up to 1500 GeV  

Science Journals Connector (OSTI)

A semiempirical formula which well represents the double-differential cross section for pion production in high-energy pp collisions is presented. The formula agrees with all data between 20 and 1500 GeV to within a factor of ?2 and is consistent with scaling and limiting fragmentation. Also presented is a set of momentum spectra at some interesting energies.

C. L. Wang

1973-05-01T23:59:59.000Z

215

Das Mischungsverhalten von Nb3Sn mit Mo3Si, Mo3Ge und Nb3Ge  

Science Journals Connector (OSTI)

Mittels homogenisierter Sinter-und Schmelzproben wird die Bildung von lckenlosen Mischreihen zwischen Nb3Sn mit Mo3Si, Mo3Ge und Nb3Ge nachgewiesen.

H. Holleck; F. Benesovsky; H. Nowotny

1962-01-01T23:59:59.000Z

216

Solar neutrino physics: Sensitivity to light dark matter particles  

E-Print Network [OSTI]

Neutrinos are produced in several neutrino nuclear reactions of the proton-proton chain and carbon-nitrogen-oxygen cycle that take place at different radius of the Sun's core. Hence, measurements of solar neutrino fluxes provide a precise determination of the local temperature. The accumulation of non-annihilating light dark matter particles (with masses between 5 GeV and 16 GeV in the Sun produces a change in the local solar structure, namely, a decrease in the central temperature of a few percent. This variation depends on the properties of the dark matter particles, such as the mass of the particle and its spin-independent scattering cross-section on baryon-nuclei, specifically, the scattering with helium, oxygen, and nitrogen among other heavy elements. This temperature effect can be measured in almost all solar neutrino fluxes. In particular, by comparing the neutrino fluxes generated by stellar models with current observations, namely 8B neutrino fluxes, we find that non-annihilating dark matter particles with a mass smaller than 10 GeV and a spin-independent scattering cross-section with heavy baryon-nuclei larger than 3 x 10^{-37} cm^-2 produce a variation in the 8B neutrino fluxes that would be in conflict with current measurements.

Ilidio Lopes; Joseph Silk

2013-09-29T23:59:59.000Z

217

GE_Order_and_Compromise_Agreement.pdf  

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

GE Appliances, a Division of GE Appliances, a Division of General Electric Company, Respondent ) ) ) ) ) ) ORDER By the General Counsel, U.S. Department of Energy: Case Number: 2012-SE-1403 1. In this Order, I adopt the attached Compromise Agreement entered into between the U.S. Department of Energy ("DOE") and GE Appliances, a Division of General Electric Company ("Respondent"). The Compromise Agreement resolves the case initiated after DOE was informed, based on test results made available as a result of verification testing by the Association of Home Appliance Manufacturers ("AHAM"), that aGE refrigerator basic model may not meet the energy conservation standard set forth in 10 C.F.R. § 430.32(a). 2. DOE and Respondent have negotiated the terms of the Compromise Agreement that

218

Working in the Cleanroom | GE Global Research  

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

The Dirt on the Cleanroom The Dirt on the Cleanroom In this short video, take a look inside the GE Global Research cleanroom and meet the team working in this 28,000-square-foot...

219

Metal MEMS Devices | GE Global Research  

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

MEMS: Inside the Global Research Cleanroom MEMS: Inside the Global Research Cleanroom This follow-up to our introduction to MEMS takes you inside the GE Global Research cleanroom...

220

Adam Rasheed | Inventors | GE Global Research  

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

A GE-NASA effort that developed the world's first and largest multi-tube pulse detonation engine that fires into a large-scale turbine-along with its deafening whine and...

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


221

Air Traffic Operations | GE Global Research  

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

Manufacturing in Europe LucasMaltaairplaneV Green Skies of Brazil 2-7-7-v-laser-additive-manufacturing Revolutionizing the Age-Old Rules of Manufacturing 3-4-4-v GE...

222

MEXICO: GE Lets Mexicans Buy In  

Science Journals Connector (OSTI)

MEXICO: GE Lets Mexicans Buy In ... General Electric de Mexico, the country's biggest manufacturer of electrical products, had been one of the major Mexican firms still wholly owned by a foreign parent. ...

1968-07-15T23:59:59.000Z

223

Andrew Gorton | Inventors | GE Global Research  

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

"My goal is to make the world a better place by reducing the amount of water used during hydraulic fracturing, as well as continue to make GE products quieter, thereby reducing...

224

GE's Christine Furstoss Named to NACIE  

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

companies like GE will need workers with new and advanced skills in areas like 3D printing and virtual design. It's all about growing a new generation of workforce skills,...

225

Jie Shen | Inventors | GE Global Research  

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

GE Power Conversion in developing the novel medium-voltage drive MV6 series, from NTI (new technology introduction) to NPI (new product introduction) to product release and to...

226

Mess(ge)rinne f, (n)  

Science Journals Connector (OSTI)

Mess(ge)rinne f, (n), Messkanal m ? flume, sluice, measuring flume, measuring sluice, meter flume, measurement flume, launder, measurement sluice, meter sluice [A channel in which water i...

2013-01-01T23:59:59.000Z

227

RESEARCH HIGHLIGHTS Dark matter lost and found  

E-Print Network [OSTI]

-component condensate.They considered the limited access inherent to samples confined in a diamond anvil cell the gas disks of two spiral galaxies merge. As spirals have dark-matter haloes, their elliptical offspring­Einstein condensate within a ring- shaped magnetic trap (Phys. Rev. Lett. (in the press); preprint at http

Loss, Daniel

228

GE Scientists Source Best Ideas at hackMIT | GE Global Research  

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

the Manufacturing Platform DirectWriteV Building More Intelligent GE Products with Additive Manufacturing MEMSVertical Next-gen RF MEMS Switch for a Smarter, Faster...

229

GE partners with Matthew Dear to create "Drop Science" | GE Global...  

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

to Create "Drop Science" GE Partners with Matthew Dear to Create "Drop Science" Every machine has its own acoustic signature - a precise frequency that indicates whether that...

230

GE Opens New Global R&D Center in Brazil - GE Global Research  

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

Center to focus on subsea oil and gas research, capitalizing on 1.2 trillion offshore market opportunity Site will include "Crotonville" GE leadership facility to help...

231

The Matter of Detailing  

Science Journals Connector (OSTI)

Project success is truly a matter of detailing! So, it is imperative that the strongest of cases must be made for the process of detailing!

Ralph W. Liebing RA; CSI; CPCA; CBO

2011-01-01T23:59:59.000Z

232

EMSL - soil organic matter  

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

soil-organic-matter en Structures and Stabilities of (MgO)n Nanoclusters. http:www.emsl.pnl.govemslwebpublicationsstructures-and-stabilities-mgon-nanoclusters

233

The Maximum Patch Method for Directional Dark Matter Detection  

E-Print Network [OSTI]

Present and planned dark matter detection experiments search for WIMP-induced nuclear recoils in poorly known background conditions. In this environment, the maximum gap statistical method provides a way of setting more sensitive cross section upper limits by incorporating known signal information. We give a recipe for the numerical calculation of upper limits for planned directional dark matter detection experiments, that will measure both recoil energy and angle, based on the gaps between events in two-dimensional phase space.

Shawn Henderson; Jocelyn Monroe; Peter Fisher

2008-01-10T23:59:59.000Z

234

Maximum patch method for directional dark matter detection  

SciTech Connect (OSTI)

Present and planned dark matter detection experiments search for WIMP-induced nuclear recoils in poorly known background conditions. In this environment, the maximum gap statistical method provides a way of setting more sensitive cross section upper limits by incorporating known signal information. We give a recipe for the numerical calculation of upper limits for planned directional dark matter detection experiments, that will measure both recoil energy and angle, based on the gaps between events in two-dimensional phase space.

Henderson, Shawn; Monroe, Jocelyn; Fisher, Peter [Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Laboratory for Nuclear Science, MIT Kavli Institute for Astrophysics and Space Research, Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

2008-07-01T23:59:59.000Z

235

Neutrinos in IceCube/KM3NeT as probes of dark matter substructures in galaxy clusters  

Science Journals Connector (OSTI)

Galaxy clusters are one of the most promising candidate sites for dark matter (DM) annihilation. We focus on DM (?) with mass in the range of 10GeV100TeV, annihilating through the channels ????+?-, ?????, ???tt, or ???????, and forecast the expected sensitivity to the annihilation cross section into these channels by observing galaxy clusters at IceCube/KM3NeT. Optimistically, the presence of DM substructures in galaxy clusters is predicted to enhance the signal by 23 orders of magnitude over the contribution from the smooth component of the DM distribution. Optimizing for the angular size of the region of interest for galaxy clusters, the sensitivity to the annihilation cross section, ??v?, of heavy DM with mass in the range of 300GeV100TeV will be O(10-24??cm3?s-1) for full IceCube/KM3NeT live time of 10years, which is about one order of magnitude better than the best limit that can be obtained by observing the MilkyWay halo. We find that neutrinos from cosmic ray interactions in the galaxy cluster, in addition to the atmospheric neutrinos, are a source of background. We show that significant improvement in the experimental sensitivity can be achieved for lower DM masses in the range of 10300GeV if neutrino-induced cascades can be reconstructed to ?5 accuracy, as may be possible in KM3NeT. We, therefore, propose that a low-energy extension KM3NeT-Core, similar to DeepCore in IceCube, be considered for an extended reach at low DM masses.

Basudeb Dasgupta and Ranjan Laha

2012-11-01T23:59:59.000Z

236

Money Matters Parent Presentation  

E-Print Network [OSTI]

Money Matters Parent Presentation Presented by Becky Lore June 7, 2014 #12;Money Matters · Dates.fcac-acfc.gc.ca · Gail Vaz-Oxlade My Money, My Choices www.gailvazoxlade.com · Money Mentors www.moneymentors.ca/ · Money

Seldin, Jonathan P.

237

Imprints of nonthermal Wino dark matter on small-scale structure  

Science Journals Connector (OSTI)

We study how warm the Wino dark matter is when it is nonthermally produced by the decays of the gravitino in the early Universe. We clarify the energy distribution of the Wino at the decay of the gravitino and the energy loss process after their production. By solving the Boltzmann equation, we show that a sizable fraction of the Wino dark matter can be warm for the Wino mass mw?100500??GeV. The warmness of the Wino dark matter leaves imprints on the matter power spectra and may provide further insights on the origin of dark matter via the future 21cm line survey. Our calculations can be applied to other nonthermal Wino production scenarios such as the Wino dark matter produced by the decay of the moduli fields.

Masahiro Ibe; Ayuki Kamada; Shigeki Matsumoto

2013-03-12T23:59:59.000Z

238

Measuring the mass of dark matter at the LHC  

Science Journals Connector (OSTI)

Many methods have been developed for measuring the mass of invisible particles that only use kinematic information available at hadron colliders. Because a particle is identified by its mass, these methods are critical when distinguishing between dark matter and fake dark matter, where a neutrino or other massless states can mimic a dark-matter signal. However, the uncertainty associated with measuring the mass of an invisible particle could be so large that it is indistinguishable from a neutrino. MonteCarlo is used to estimate lower bounds on how heavy an invisible particle must be in order for it to be distinguishable from a massless one at 95%CL, which we estimate to be O(10??GeV). This result, to a good approximation, is independent of the way the massive final-state particle is produced. If there is a light dark-matter particle with mass O(10??GeV), its presence will be difficult to unambiguously identify at the LHC, using kinematic information alone.

Andrew C. Kobach

2013-12-02T23:59:59.000Z

239

Relaxation and recombination processes in Ge/SiGe multiple quantum wells  

SciTech Connect (OSTI)

The carrier dynamics that occurs in Ge/SiGe QWs when electrons are excited to confined states at ? is studied by means of optical spectroscopy at different lattice temperatures. The typical times for the different relaxation and recombination processes are given and discussed.

Gatti, E., E-mail: gatti@mater.unimib.it; Giorgioni, A., E-mail: gatti@mater.unimib.it; Grilli, E., E-mail: gatti@mater.unimib.it; Guzzi, M., E-mail: gatti@mater.unimib.it [L-NESS and Universit di Milano-Bicocca, Dip. di Scienza dei Materiali, via Cozzi 53, 20125 Milano (Italy); Chrastina, D.; Isella, G. [L-NESS and Politecnico di Milano, Dip. di Fisica, via Anzani 42, 22100 Como (Italy); Chernikov, A.; Kolata, K.; Bornwasser, V.; Kster, N. S.; Woscholski, R.; Chatterjee, S. [Faculty of Physics and Materials Sciences Center, Philipps-Universitt, Renthof 5, 35032 Marburg (Germany)

2013-12-04T23:59:59.000Z

240

Newtonian Collapse of Scalar Field Dark Matter  

E-Print Network [OSTI]

In this letter, we develop a Newtonian approach to the collapse of galaxy fluctuations of scalar field dark matter under initial conditions inferred from simple assumptions. The full relativistic system, the so called Einstein-Klein-Gordon, is reduced to the Schr\\"odinger-Newton one in the weak field limit. The scaling symmetries of the SN equations are exploited to track the non-linear collapse of single scalar matter fluctuations. The results can be applied to both real and complex scalar fields.

F. Siddhartha Guzman; L. Arturo Urena-Lopez

2003-03-19T23:59:59.000Z

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


241

Isospin-Violating Dark Matter and Neutrinos From the Sun  

E-Print Network [OSTI]

We study the indirect detection of dark matter through neutrino flux from their annihilation in the center of the Sun, in a class of theories where the dark matter-nucleon spin-independent interactions break the isospin symmetry. We point out that, while the direct detection bounds with heavy targets like Xenon are weakened and reconciled with the positive signals in DAMA and CoGeNT experiments, the indirect detection using neutrino telescopes can impose a relatively stronger constraint and brings tension to such explanation, if the annihilation is dominated by heavy quark or $\\tau$-lepton final states. As a consequence, the qualified isospin violating dark matter candidate has to preferably annihilate into light flavors.

Shao-Long Chen; Yue Zhang

2011-06-20T23:59:59.000Z

242

Dark matter and dark energy production in quantum model of the universe  

E-Print Network [OSTI]

The quantum model of the homogeneous, isotropic, and spatially closed universe predicts an existence of two types of collective quantum states in the universe. The states of one type characterize a gravitational field, the others describe a matter (uniform scalar) field. In the first stage of the evolution of the universe a primordial scalar field evolves slowly into its vacuum-like state. In the second stage the scalar field oscillates about an equilibrium due to the quantum fluctuations. The universe is being filled with matter in the form of elementary quantum excitations of the vibrations of the scalar field. The separate quantum excitations are characterized by non-zero values of their energies (masses). Under the action of gravitational forces mainly these excitations decay into ordinary particles (baryons and leptons) and dark matter. The elementary quantum excitations of the vibrations of the scalar field which have not decayed up to now form dark energy. The numerical estimations lead to realistic values of both the matter density \\Omega_{M} = 0.29 (with the contributions from dark matter, \\Omega_{DM} = 0.25, and optically bright baryons, \\Omega_{stars} = 0.0025) and the dark energy density \\Omega_{X} = 0.71 if one takes that the mean energy ~ 10 GeV is released in decay of dark energy quantum and fixes baryonic component \\Omega_{B} = 0.04 according to observational data. The energy (mass) of dark energy quantum is equal to ~ 17 GeV and the energy > 2 x 10^{10} GeV is needed in order to detect it. Dark matter particle has the mass ~ 6 GeV. The Jeans mass for dark matter which is considered as a gas of such massive particles is equal to M_{J} ~ 10^{5} M_{\\odot}.

V. E. Kuzmichev; V. V. Kuzmichev

2004-05-24T23:59:59.000Z

243

Kohlenstoffhaltige ternre Verbindungen (V-Ge-C, Nb-Ga-C, Ta-Ga-C, Ta-Ge-C, Cr-Ga-C und Cr-Ge-C)  

Science Journals Connector (OSTI)

Die ternren Phasen V2GeC, Cr2GaC und Cr2GeC werden aus den Komponenten hergestellt und als H-Phasen identifiziert. Ferner drften auch die H-Phasen Ti2GaC, und Ti2GeC existieren. In gleicher Weise hergestellte L...

W. Jeitschko; H. Nowotny; F. Benesovsky

1963-01-01T23:59:59.000Z

244

Influence of C on Ge incorporation in the growth of Ge-rich Ge1?x?ySixCy alloys on Si (100)  

Science Journals Connector (OSTI)

Ge-rich Ge1?x?ySixCy...alloys have been grown on Si (100) substrates by plasma-enhanced rapid thermal chemical vapor deposition. It is found that there is a strong suppressive effect of C on the Ge composition an...

X.B. Liu; L. Zang; S.M. Zhu; X.M. Cheng; P. Han; Z.Y. Luo; Y.D. Zheng

2000-04-01T23:59:59.000Z

245

Light dark matter from the U(1){sub X} sector in the NMSSM with gauge mediation  

SciTech Connect (OSTI)

Cosmic ray anomalies observed by PAMELA and Fermi-LAT experiments may be interpreted by heavy (TeV-scale) dark matter annihilation enhanced by Sommerfeld effects mediated by a very light (sub-GeV) U(1){sub X} gauge boson, while the recent direct searches from CoGeNT and DAMA/LIBRA experiments may indicate a rather light ( ? 7 GeV) dark matter with weak interaction. Motivated by these apparently different scales, we consider a gauge mediated next-to-the minimal supersymmetric standard model (NMSSM) entended with a light U(1){sub X} sector plus a heavy sector ( H-bar {sub h},H{sub h}), which can provide both a light ( ? 7 GeV) and a heavy (TeV-scale) dark matter without introducing any ad hoc new scale. Through the Yukawa coupling between H{sub h} and the messager fields, the U(1){sub X} gauge symmetry is broken around the GeV scale radiatively and a large negative m{sub S}{sup 2} is generated for the NMSSM singlet S. Furthermore, the small kinetic mixing parameter between U(1){sub X} and U(1){sub Y} is predicted to be ? ? 10{sup ?5}?10{sup ?6} after integrating out the messengers. Such a light dark matter, which can have a normal relic density from the late decay of the right-handed sneutrino (assumed to be the ordinary next-to-the lightest supersymmetric particle and thermally produced in the early Universe), can serve a good candidate to explain the recent CoGeNT and DAMA/LIBRA results.

Kang, Zhaofeng; Li, Tianjun; Liu, Tao; Tong, Chunli; Yang, Jin Min, E-mail: zhfkang@itp.ac.cn, E-mail: tli@itp.ac.cn, E-mail: tliuphy@itp.ac.cn, E-mail: piggy1983@gmail.com, E-mail: jmyang@itp.ac.cn [Key Laboratory of Frontiers in Theoretical Physics, Institute of Theoretical Physics, Academia Sinica, Zhongguancun East Road, Beijing 100190 (China)

2011-01-01T23:59:59.000Z

246

New YorkPresbyterian and GE  

Science Journals Connector (OSTI)

...originate. Our collaboration with GE Medical Systems is based on having access to business skills and cutting-edge equipment that, in our judgment, will benefit our patients and increase our ability to provide cost-effective, high-quality care. We purchase from GE only technology that the hospital deems... To the Editor: In his Perspective article, Dr. Garber (Oct. 14 issue)1 appropriately alerts us to the potential for conflicts of interest when an academic medical center forms a relationship with a business company. New YorkPresbyterian Hospital is very ...

2005-02-03T23:59:59.000Z

247

Matter Waves and Electricity  

Science Journals Connector (OSTI)

Classical four-dimensional relativity gives a most natural and harmonious interpretation of the three basic phenomena of nature: gravity, electricity, and the wave structure of matter, provided that the basic assumptions of the Einsteinian theory are modified in two respects: (1) the fundamental invariant of the action principle is chosen as a quadratic instead of a linear function of the curvature components; (2) the static equilibrium of the world is replaced by a dynamic equilibrium. Electricity comes out as a second-order resonance effect of the matter waves. The matter waves are gravitational waves but superposed not on an empty Euclidean space but on a space of high average curvature.

Cornelius Lanczos

1942-06-01T23:59:59.000Z

248

Dark matter-motivated searches for exotic fourth-generation mirror quarks in Tevatron and early LHC data  

SciTech Connect (OSTI)

We determine the prospects for finding dark matter at the Tevatron and LHC through the production of exotic fourth-generation mirror quarks T{sup '} that decay through T{sup '{yields}}tX, where X is dark matter. The resulting signal of tt+Ee{sub T} has not previously been considered in searches for fourth-generation quarks, but there are both general and specific dark matter motivations for this signal, and with slight modifications, this analysis applies to any scenario where invisible particles are produced in association with top quarks. Current direct and indirect bounds on such exotic quarks restrict their masses to be between 300 and 600 GeV, and the dark matter's mass may be anywhere below m{sub T}{sup '}. We simulate the signal and main backgrounds with MadGraph/MadEvent-Pythia-PGS4. For the Tevatron, we find that an integrated luminosity of 20 fb{sup -1} will allow 3{sigma} discovery up to m{sub T}{sup '}=400 GeV and 95% exclusion up to m{sub T}{sup '}=455 GeV. For the 10 TeV LHC with 300 pb{sup -1}, the discovery and exclusion sensitivities rise to 490 GeV and 600 GeV. These scenarios are therefore among the most promising for dark matter at colliders. Perhaps most interestingly, we find that dark matter models that can explain results from the DAMA, CDMS, and CoGeNT collaborations can be tested with high statistical significance using data already collected at the Tevatron and have extraordinarily promising implications for early runs of the LHC.

Alwall, Johan [Department of Physics and National Center for Theoretical Sciences, National Taiwan University, Taipei 10617, Taiwan (China); Feng, Jonathan L. [Department of Physics and Astronomy, University of California, Irvine, California 92697 (United States); Kumar, Jason [Department of Physics and Astronomy, University of Hawaii, Honolulu, Hawaii 96822 (United States); Su Shufang [Department of Physics, University of Arizona, Tucson, Arizona 85721 (United States)

2010-06-01T23:59:59.000Z

249

Hot and dark matter  

E-Print Network [OSTI]

In this thesis, we build new Effective Field Theory tools to describe the propagation of energetic partons in hot and dense media, and we propose two new reactions for dark matter in the early universe. In the first part, ...

D'Eramo, Francesco

2012-01-01T23:59:59.000Z

250

The Heart of Matter  

E-Print Network [OSTI]

In this article I trace the development of the human understanding of the "Heart of Matter" from early concepts of "elements" (or alternatively "Panchmahabhootas") to the current status of "quarks" and "leptons" as the fundamental constituents of matter, interacting together via exchange of the various force carrier particles called "gauge bosons" such as the photon, W/Z-boson etc. I would like to show how our understanding of the fundamental constituents of matter has gone hand in hand with our understanding of the fundamental forces in nature. I will also outline how the knowledge of particle physics at the "micro" scale of less than a Fermi(one millionth of a nanometer), enables us to offer explanations of Cosmological observations at the "macro" scale. Consequently these observations, may in turn, help us address some very fundamental questions of the Physics at the "Heart of the Matter".

Godbole, Rohini M

2010-01-01T23:59:59.000Z

251

The Heart of Matter  

E-Print Network [OSTI]

In this article I trace the development of the human understanding of the "Heart of Matter" from early concepts of "elements" (or alternatively "Panchmahabhootas") to the current status of "quarks" and "leptons" as the fundamental constituents of matter, interacting together via exchange of the various force carrier particles called "gauge bosons" such as the photon, W/Z-boson etc. I would like to show how our understanding of the fundamental constituents of matter has gone hand in hand with our understanding of the fundamental forces in nature. I will also outline how the knowledge of particle physics at the "micro" scale of less than a Fermi(one millionth of a nanometer), enables us to offer explanations of Cosmological observations at the "macro" scale. Consequently these observations, may in turn, help us address some very fundamental questions of the Physics at the "Heart of the Matter".

Rohini M. Godbole

2010-06-30T23:59:59.000Z

252

Atomic dark matter  

SciTech Connect (OSTI)

We propose that dark matter is dominantly comprised of atomic bound states. We build a simple model and map the parameter space that results in the early universe formation of hydrogen-like dark atoms. We find that atomic dark matter has interesting implications for cosmology as well as direct detection: Weak-scale dark atoms can accommodate hyperfine splittings of order 100 keV, consistent with the inelastic dark matter interpretation of the DAMA data while naturally evading direct detection bounds. Moreover, protohalo formation can be suppressed below M{sub proto} ? 10{sup 3}10{sup 6}M{sub s}un for weak scale dark matter due to Ion-Radiation and Ion-Atom interactions in the dark sector.

Kaplan, David E.; Krnjaic, Gordan Z.; Rehermann, Keith R.; Wells, Christopher M., E-mail: dkaplan@pha.jhu.edu, E-mail: gordan@pha.jhu.edu, E-mail: keith@pha.jhu.edu, E-mail: cwells13@pha.jhu.edu [Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218-2686 (United States)

2010-05-01T23:59:59.000Z

253

GE Hitachi Nuclear Energy | Open Energy Information  

Open Energy Info (EERE)

GE Hitachi Nuclear Energy GE Hitachi Nuclear Energy Jump to: navigation, search Name GE Hitachi Nuclear Energy Place Wilmington, North Carolina Zip 28402 Sector Efficiency, Services Product GE Hitachi Nuclear Energy develops advanced light water reactors and offers products and services used by operators of boiling water reactor (BWR) nuclear power plants to improve efficiency and boost output. Coordinates 42.866922°, -72.868494° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":42.866922,"lon":-72.868494,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

254

Viscosity Measurement G.E. Leblanc  

E-Print Network [OSTI]

30 Viscosity Measurement G.E. Leblanc McMaster University R.A. Secco The University of Western Ontario 30.1 Shear Viscosity ............................................................. 30-l Newtonian and Non-Newtonian Fluids l Dimensions and Units of Viscosity l Viscometer Types l Capillary M. Kostic

Kostic, Milivoje M.

255

Sensitivity of the IceCube neutrino detector to dark matter annihilating in dwarf galaxies  

Science Journals Connector (OSTI)

In this paper, we compare the relative sensitivities of gamma-ray and neutrino observations to the dark matter annihilation cross section in leptophilic models such as have been designed to explain PAMELA data. We investigate whether the high energy neutrino telescope IceCube will be competitive with current and upcoming searches by gamma-ray telescopes, such as the Atmospheric erenkov Telescopes (H.E.S.S., VERITAS, and MAGIC), or the Fermi Gamma-Ray Space Telescope, in detecting or constraining dark matter particles annihilating in dwarf spheroidal galaxies. We find that after 10 years of observation of the most promising nearby dwarfs, IceCube will have sensitivity comparable to the current sensitivity of gamma-ray telescopes only for very heavy (mX?7??TeV) or relatively light (mX?200??GeV) dark matter particles which annihilate primarily to ?+?-. If dark matter particles annihilate primarily to ?+?-, IceCube will have superior sensitivity only for dark matter particle masses below the 200GeV threshold of current Atmospheric erenkov Telescopes. If dark matter annihilations proceed directly to neutrino-antineutrino pairs a substantial fraction of the time, IceCube will be competitive with gamma-ray telescopes for a much wider range of dark matter masses.

Pearl Sandick; Douglas Spolyar; Matthew Buckley; Katherine Freese; Dan Hooper

2010-04-05T23:59:59.000Z

256

STATEMENT OF CONSIDERATIONS REQUEST BY GE CORPORATE RESEARCH & DEVELOPMENT (GE-CRD)  

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

CORPORATE RESEARCH & DEVELOPMENT (GE-CRD) CORPORATE RESEARCH & DEVELOPMENT (GE-CRD) FOR AN ADVANCE WAIVER OF DOMESTIC AND FOREIGN PATENT RIGHTS UNDER DOE COOPERATIVE AGREEMENT NO. DE-FC07- 96ID13406; W(A)-96-004; CH-0894 The Petitioner, GE Corporate Research & Development (GE-CRD) has requested a waiver of domestic and foreign patent rights for all subject inventions arising from its participation under the above referenced cooperative agreement entitled "Electric Vehicle Program - Ultracapacitor/Battery Electronic Interface Project." The objective of the cooperative agreement is to develop prototype electronic interface hardware to verify the design of the power electronics and basic control strategy for an advanced electric vehicle drive line that uses ultracapacitors to load level the main storage battery. The

257

Defect luminescence in films containing Ge and GeO{sub 2} nanocrystals  

SciTech Connect (OSTI)

Amorphous SiO{sub x} alloys containing Ge or GeO{sub 2} nanocrystals are produced by dc-magnetron sputtering and controlled crystallization. The samples are investigated by Raman scattering, transmission electron microscopy, photoluminescence and excitation spectroscopy. Under UV excitation, both types of films luminesce around 3.1 eV, with identical PL line shapes and subnanosecond PL dynamics. The strongest PL intensity is found for the films containing FeO{sub 2} crystals and for the largest nanocrystals. These results are a clear indication that although the blue luminescence is without a doubt correlated with the formation of Ge (or GeO{sub 2}) nanocrystals, it is not produced by the radiative recombination of excitons confined in the nanocrystals. Possible mechanisms for the luminescence are discussed, including defects at the nanocrystal/matric interface or in the matrix itself.

Zacharias, M.; Atherton, S.J.; Fauchet, P.M.

1997-07-01T23:59:59.000Z

258

Past and present of nuclear matter  

SciTech Connect (OSTI)

The subject of nuclear matter is interesting for many fields of physics ranging from condensed matter to lattice QCD. Knowing its properties is important for our understanding of neutron stars, supernovae and cosmology. Experimentally, we have the most precise information on ground state nuclear matter from the mass formula and from the systematics of monopole vibrations. This gives us the ground state density, binding energy and the compression modulus k at ground state density. However, those methods can not be extended towards the regime we are most interested in, the regime of high density and high temperature. Additional information can be obtained from the observation of neutron stars and of supernova explosions. In both cases information is limited by the rare events that nature provides for us. High energy heavy ion collisions, on the other hand, allow us to perform controlled experiments in the laboratory. For a very short period in time we can create a system that lets us study nuclear matter properties. Density and temperature of the system depend on the mass of the colliding nuclei, on their energy and on the impact parameter. The system created in nuclear collisions has at best about 200 constituents not even close to infinite nuclear matter, and it lasts only for collision times of {approx} 10{sup {minus}22}sec, not an ideal condition for establishing any kind of equilibrium. Extended size and thermal and chemical equilibrium, however, axe a priori conditions of nuclear matter. As a consequence we need realistic models that describe the collision dynamics and non-equilibrium effects in order to relate experimental observables to properties of nuclear matter. The study of high energy nuclear collisions started at the Bevalac. I will try to summarize the results from the Bevalac studies, the highlights of the continuing program, and extension to higher energies without claiming to be complete.

Ritter, H.G.

1994-05-01T23:59:59.000Z

259

Silicon Carbides in the Cleanroom | GE Global Research  

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

Clean Room: Silicon Carbides GE Global Research is working on nanoscale silicon carbide devices. Find out what we're doing. You Might Also Like 2-1-10-v-working-at-ge-resear...

260

The Majorana Ge-76 double-beta decay project  

SciTech Connect (OSTI)

The MAJORANA Project is a research and development activity set up to establish the feasibility and cost of a doublebetadecay experiment comprising a one-ton array of Ge detectors fabricated from germanium enriched to about 86% in Ge-76.

Avignone, Frank Titus [ORNL

2010-01-01T23:59:59.000Z

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


261

Conservation of bond lengths in strained Ge-Si layers  

Science Journals Connector (OSTI)

The combined techniques of x-ray-absorption fine structure and x-ray diffraction have been used to study the strain and bond distortions in epitaxial Ge-Si on Si(001). In a 31% Ge, 340- pseudomorphic Ge-Si film, the Ge-Ge and Ge-Si first-neighbor bond lengths have been found to be 2.440.02 and 2.380.02 , respectively. The lattice parameter perpendicular to the Ge-Si/Si(001) interface has been found to be a?=5.5520.002 , in agreement with the predictions of macroscopic elastic theory. These results show that the bond-length strain in the epitaxial layer appears in the second and higher coordination shells, rather than in the nearest-neighbor bond lengths, which remain the same as in unstrained Ge-Si. A microscopic model is presented that accounts for these findings.

J. C. Woicik; C. E. Bouldin; M. I. Bell; J. O. Cross; D. J. Tweet; B. D. Swanson; T. M. Zhang; L. B. Sorensen; C. A. King; J. L. Hoyt; P. Pianetta; J. F. Gibbons

1991-01-15T23:59:59.000Z

262

Tailoring the spin polarization in Ge/SiGe multiple quantum wells  

SciTech Connect (OSTI)

We performed spin-resolved photoluminescence measurements on Ge/SiGe multiple quantum wells with different well thickness and using different exciting power densities. The polarization of the direct emission strongly depends on the relative weight of electrons photoexcited from the light and the heavy hole subbands. The study of the polarization as a function of the exciting power highlights the role of the carrier-carrier interactions in determining spin depolarization.

Giorgioni, Anna; Pezzoli, Fabio; Gatti, Eleonora; Grilli, Emanuele; Guzzi, Mario [LNESS-Dipartimento di Scienza dei Materiali, Universit degli Studi di Milano-Bicocca, I-20125 Milano (Italy); Bottegoni, Federico; Cecchi, Stefano; Ciccacci, Franco; Isella, Giovanni [LNESS-Dipartimento di Fisica, Politecnico di Milano, I-20133 Milano (Italy); Trivedi, Dhara; Song, Yang [Department of Physics and Astronomy, University of Rochester, Rochester (United States); Li, Pengki [Department of Electrical and Computer Engineering, University of Rochester, Rochester (United States); Dery, Hanan [Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627 and Department of Electrical and Computer Engineering, University of Rochester, Rochester (United States)

2013-12-04T23:59:59.000Z

263

Symmetry Energy I: Semi-Infinite Matter  

E-Print Network [OSTI]

Nuclear energy is considered in the macroscopic limit for a nucleus. Considered, further, is the Hohenberg-Kohn functional for a nuclear system, in terms of proton and neutron densities. Finally, Skyrme-Hartree-Fock calculations are carried out for half-infinite particle-stable nuclear matter. In each case, the attention is focused on the role of neutron-proton asymmetry and on the symmetry energy. We extend the considerations on the symmetry term from an energy formula to the respective term in the Hohenberg-Kohn functional. We show, in particular, that in continuum limit of the considered functional, and subject to possible Coulomb corrections, it is possible to construct isoscalar and isovector densities out of the proton and neutron densities, that retain a universal relation to each other, approximately independent of asymmetry. In the so-called local approximation, the isovector density is inversely proportional to the symmetry energy in uniform matter at the local isoscalar density. Generalized symmetr...

Danielewicz, Pawel

2008-01-01T23:59:59.000Z

264

VEH-0015 - In the Matter of Sub-Zero Freezer Co. | Department of Energy  

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

VEH-0015 - In the Matter of Sub-Zero Freezer Co. VEH-0015 - In the Matter of Sub-Zero Freezer Co. VEH-0015 - In the Matter of Sub-Zero Freezer Co. Motion for Evidentiary Hearing Sub-Zero Freezer Co. (Sub-Zero) filed a motion for evidentiary hearing with the Office of Hearings and Appeals (OHA) of the Department of Energy (DOE). The motion relates to Sub-Zero's appeal (Case No. VEA-0015) of our November 3 decision, in which we granted Viking Range Corporation (Viking) a six-month exception from the 2001 energy appliance efficiency standards for built-in refrigerators. Viking Range Corporation, 28 DOE ¶ 81,002 (2000). As discussed below, we have concluded that the motion should be granted in part. veh0015.pdf More Documents & Publications VEA-0015 - In the Matter of Sub-Zero Freezer Co. VEA-0016 - In the Matter of GE Appliances

265

The First Limits on the Ultra-high Energy Neutrino Fluence from Gamma-Ray Bursts  

Science Journals Connector (OSTI)

We set the first limits on the ultra-high energy (UHE) neutrino fluence at energies greater than 109?GeV from gamma-ray bursts (GRBs) based on data from the second flight of the Antarctic Impulsive Transient Antenna (ANITA). During the 31 day flight of ANITA-II, 26 GRBs were recorded by Swift or Fermi. Of these, we analyzed the 12 GRBs which occurred during quiet periods when the payload was away from anthropogenic activity. In a blind analysis, we observe 0 events on a total background of 0.0044 events in the combined prompt window for all 12 low-background bursts. We also observe 0 events from the remaining 14 bursts. We place a 90% confidence level limit on the E ?4 prompt neutrino fluence between 108?GeV E 12?GeV of E 4? = 2.5 ? 1017?GeV3?cm?2 from GRB090107A. This is the first reported limit on the UHE neutrino fluence from GRBs above 109?GeV, and the strongest limit above 108?GeV.

A. G. Vieregg; K. Palladino; P. Allison; B. M. Baughman; J. J. Beatty; K. Belov; D. Z. Besson; S. Bevan; W. R. Binns; C. Chen; P. Chen; J. M. Clem; A. Connolly; M. Detrixhe; D. De Marco; P. F. Dowkontt; M. DuVernois; P. W. Gorham; E. W. Grashorn; B. Hill; S. Hoover; M. Huang; M. H. Israel; A. Javaid; K. M. Liewer; S. Matsuno; B. C. Mercurio; C. Miki; M. Mottram; J. Nam; R. J. Nichol; A. Romero-Wolf; L. Ruckman; D. Saltzberg; D. Seckel; G. S. Varner; Y. Wang

2011-01-01T23:59:59.000Z

266

Probing annihilations and decays of low-mass galactic dark matter in IceCube DeepCore array: Track events  

Science Journals Connector (OSTI)

The deployment of DeepCore array significantly lowers IceCubes energy threshold to about 10GeV and enhances the sensitivity of detecting neutrinos from annihilations and decays of light dark matter. To match this experimental development, we calculate the track event rate in DeepCore array due to neutrino flux produced by annihilations and decays of galactic dark matter. We also calculate the background event rate due to the atmospheric neutrino flux for evaluating the sensitivity of DeepCore array to galactic dark matter signatures. Unlike previous approaches, which set the energy threshold for track events at around 50GeV (this choice avoids the necessity of including the oscillation effect in the estimation of atmospheric background event rate), we have set the energy threshold at 10GeV to take full advantage of DeepCore array. We compare our calculated sensitivity with those obtained by setting the threshold energy at 50GeV. We conclude that our proposed threshold energy significantly improves the sensitivity of DeepCore array to the dark matter signature for m?<100??GeV in the annihilation scenario and m?<300??GeV in the decay scenario.

Fei-Fan Lee and Guey-Lin Lin

2012-01-25T23:59:59.000Z

267

Upper limit on the cross section for elastic neutralino-nucleon scattering in a neutrino experiment at the Baksan Underground Scintillator Telescope  

SciTech Connect (OSTI)

The results of a neutrino experiment that involved 24.12 yr of live time of observation of muons from the lower Earth's hemisphere with the aid of the Baksan Underground Scintillator Telescope are presented. In the problem of searches for a signal from the annihilation of dark matter in the Sun, an upper limit on the cross section for the elastic scattering of a weakly interacting massive particle (WIMP) on a nucleon was obtained at a 90% confidence level from an analysis of data accumulated within 21.15 yr of live time of observation. A neutralino in a nonminimal supersymmetric theory was considered for a WIMP. The best limit at the Baksan Underground Scintillator Telescope on the cross section for spin-dependent neutralino interactionwith a proton corresponds to 3 Multiplication-Sign 10{sup -4} pb for the neutralino mass of 210 GeV/c{sup 2}. This limit is three orders of magnitude more stringent than similar limits obtained in experiments that detected directly WIMP scattering on target nuclei.

Suvorova, O. V., E-mail: suvorova@cpc.inr.ac.ru; Boliev, M. M., E-mail: boliev2005@yandex.ru; Demidov, S. V., E-mail: demidov@inr.ac.ru; Mikheyev, S. P. [Russian Academy of Sciences, Institute for Nuclear Research (Russian Federation)] [Russian Academy of Sciences, Institute for Nuclear Research (Russian Federation)

2013-11-15T23:59:59.000Z

268

Photon and graviton mass limits  

SciTech Connect (OSTI)

We review past and current studies of possible long-distance, low-frequency deviations from Maxwell electrodynamics and Einstein gravity. Both have passed through three phases: (1) Testing the inverse-square laws of Newton and Coulomb, (2) Seeking a nonzero value for the rest mass of photon or graviton, and (3) Considering more degrees of freedom, allowing mass while preserving gauge or general-coordinate invariance. For electrodynamics there continues to be no sign of any deviation. Since our previous review the lower limit on the photon Compton wavelength (associated with weakening of electromagnetic fields in vacuum over large distance scale) has improved by four orders of magnitude, to about one astronomical unit. Rapid current progress in astronomical observations makes it likely that there will be further advances. These ultimately could yield a bound exceeding galactic dimensions, as has long been contemplated. Meanwhile, for gravity there have been strong arguments about even the concept of a graviton rest mass. At the same time there are striking observations, commonly labeled 'dark matter' and 'dark energy' that some argue imply modified gravity. This makes the questions for gravity much more interesting. For dark matter, which involves increased attraction at large distances, any explanation by modified gravity would be qualitatively different from graviton mass. Because dark energy is associated with reduced attraction at large distances, it might be explained by a graviton-mass-like effect.

Nieto, Michael [Los Alamos National Laboratory; Goldhaber Scharff, Alfred [SUNY

2008-01-01T23:59:59.000Z

269

Monolithic Ge/Si Avalanche Photodiodes Yimin Kanga*  

E-Print Network [OSTI]

Monolithic Ge/Si Avalanche Photodiodes Yimin Kanga* , Mike Morsea , Mario J. Panicciaa , Moshe, Charlottesville, VA 22904, USA Abstract: We demonstrate mesa-type and waveguide-type Ge/Si avalanche photodiodes. Research on the Ge/Si photodiodes, one of the fundamental components needed for building integrated silicon

Bowers, John

270

Discussion on the Low Temperature Magnetothermal Conductivity in Lightly Doped Ge(Sb) and Ge(As)  

Science Journals Connector (OSTI)

Some time ago we reported1) measurements of magnetothermal conductivity in n-type Ge in the temperature range 1.3?T?...1): For Ge(Sb) with the field Bll ...o, is negative, increases in magnitude approximatel...

Leif Halbo

1976-01-01T23:59:59.000Z

271

Ferromagnetic Mn5Ge3C0.8contacts on Ge: work function and specific contact resistivity  

Science Journals Connector (OSTI)

We report on the study of the electrical and magnetic properties of Mn5Ge3C0.8contacts deposited on highly doped n-Ge (1?0?0) as a potentially complementary metaloxidesemiconductor (CMOS)-compatible material system for spin injection into Ge. Mn5Ge3C0.8is a ferromagnet with a Curie temperature of 445K and with a resistivity that is comparable to highly doped Ge. We extract the work function of Mn5Ge3C0.8from metaloxidesemiconductor capacitance measurements and obtain a specific contact resistivity rC = 5.0 ? cm2from transmission-line measurements. We discuss possible origins of the large specific contact resistivity of Mn5Ge3C0.8on Ge.

I A Fischer; J Gebauer; E Rolseth; P Winkel; L-T Chang; K L Wang; C Srgers; J Schulze

2013-01-01T23:59:59.000Z

272

Inclusive Reactions from ?+p at 4.1 GeV/c  

Science Journals Connector (OSTI)

At a ?+ beam momentum of 4.1 GeV/c, in reactions of the type a+b?c+X, limiting fragmentation of the beam and target particles is observed where abc is exotic, and is not observed for abc not exotic. Single-particle distributions in several different variables have been studied for ?- and ?+ mesons. The two-particle distributions and correlation functions from the reaction ?++p??-+?-+X are also presented.

Douglas G. Fong; Anatole M. Shapiro; Mildred Widgoff

1973-12-01T23:59:59.000Z

273

The dark matter self-interaction and its impact on the critical mass for dark matter evaporations inside the sun  

E-Print Network [OSTI]

We study the capture, annihilation and evaporation of dark matter (DM) inside the Sun. It has been shown that the DM self-interaction can increase the DM number inside the Sun. We demonstrate that this enhancement becomes more significant in the regime of small DM mass, given a fixed DM self-interaction cross section. This leads to the enhancement of neutrino flux from DM annihilation. On the other hand, for DM mass as low as as a few GeVs, not only the DM-nuclei scatterings can cause the DM evaporation, DM self-interaction also provides non-negligible contributions to this effect. Consequently, the critical mass for DM evaporation (typically 3 ~ 4 GeV without the DM self-interaction) can be slightly increased. We discuss the prospect of detecting DM self-interaction in IceCube- PINGU using the annihilation channels $\\chi\\chi\\rightarrow\

Chian-Shu Chen; Fei-Fan Lee; Guey-Lin Lin; Yen-Hsun Lin

2014-12-21T23:59:59.000Z

274

Pre-launch Estimates for GLAST Sensitivity to Dark Matter Annihilation Signals  

SciTech Connect (OSTI)

We investigate the sensitivity of the Gamma-ray Large Area Space Telescope (GLAST) to indirectly detect weakly interacting massive particles (WIMPs) through the {gamma}-ray signal that their pair annihilation produces. WIMPs are among the favorite candidates to explain the compelling evidence that about 80% of the mass in the Universe is non-baryonic dark matter (DM). They are serendipitously motivated by various extensions of the standard model of particle physics such as Supersymmetry and Universal Extra Dimensions (UED). With its unprecedented sensitivity and its very large energy range (20 MeV to more than 300 GeV) the main instrument on board the GLAST satellite, the Large Area Telescope (LAT), will open a new window of discovery. As our estimates show, the LAT will be able to detect an indirect DM signature for a large class of WIMP models given a cuspy profile for the DM distribution. Using the current state of the art Monte Carlo and event reconstruction software developed within the LAT collaboration, we present preliminary sensitivity studies for several possible sources inside and outside the Galaxy. We also discuss the potential of the LAT to detect UED via the electron/positron channel. Diffuse background modeling and other background issues that will be important in setting limits or seeing a signal are presented.

Baltz, E.A.; Berenji, B.; /SLAC /KIPAC, Menlo Park; Bertone, G.; /Paris, Inst. Astrophys.; Bergstrom, L.; /Stockholm U.; Bloom, E.; /SLAC /KIPAC, Menlo Park; Bringmann, T.; /Stockholm U.; Chiang, J.; Cohen-Tanugi, J.; /SLAC /KIPAC, Menlo Park; Conrad, J.; /Stockholm U.; Edmonds, Y.; /SLAC /KIPAC, Menlo Park; Edsjo, J.; /Stockholm U.; Godfrey, G.; /SLAC /KIPAC, Menlo Park; Hughes, R.E.; /Ohio State U.; Johnson, R.P.; /UC, Santa Cruz; Lionetto, A.; /Rome U.,Tor Vergata /INFN, Rome2; Moiseev, A.A.; /CRESST; Morselli, A.; /Rome U.,Tor Vergata /INFN, Rome2; Moskalenko, I.V.; /Stanford U., HEPL /KIPAC, Menlo Park; Nuss, E.; /Montpellier U.; Ormes, J.F.; /Denver U.; Rando, R.; /INFN, Padua /Ohio State U. /Stockholm U. /Ohio State U. /Garching, Max Planck Inst., MPE /SLAC /KIPAC, Menlo Park /Ohio State U.

2009-05-15T23:59:59.000Z

275

Conservative constraints on dark matter annihilation into gamma rays  

SciTech Connect (OSTI)

Using gamma-ray data from observations of the Milky Way, Andromeda (M31), and the cosmic background, we calculate conservative upper limits on the dark matter self-annihilation cross section to monoenergetic gamma rays, <{sigma}{sub A}v>{sub {gamma}}{sub {gamma}}, over a wide range of dark matter masses. (In fact, over most of this range, our results are unchanged if one considers just the branching ratio to gamma rays with energies within a factor of a few of the endpoint at the dark matter mass.) If the final-state branching ratio to gamma rays, Br({gamma}{gamma}), were known, then <{sigma}{sub A}v>{sub {gamma}}{sub {gamma}}/Br({gamma}{gamma}) would define an upper limit on the total cross section; we conservatively assume Br({gamma}{gamma}) > or approx. 10{sup -4}. An upper limit on the total cross section can also be derived by considering the appearance rates of any standard model particles; in practice, this limit is defined by neutrinos, which are the least detectable. For intermediate dark matter masses, gamma-ray-based and neutrino-based upper limits on the total cross section are comparable, while the gamma-ray limit is stronger for small masses and the neutrino limit is stronger for large masses. We comment on how these results depend on the assumptions about astrophysical inputs and annihilation final states, and how GLAST and other gamma-ray experiments can improve upon them.

Mack, Gregory D.; Yueksel, Hasan [Department of Physics, Ohio State University, Columbus, Ohio 43210 (United States); Center for Cosmology and Astro-Particle Physics, Ohio State University, Columbus, Ohio 43210 (United States); Jacques, Thomas D.; Bell, Nicole F. [School of Physics, The University of Melbourne, Victoria 3010 (Australia); Beacom, John F. [Department of Physics, Ohio State University, Columbus, Ohio 43210 (United States); Center for Cosmology and Astro-Particle Physics, Ohio State University, Columbus, Ohio 43210 (United States); Department of Astronomy, Ohio State University, Columbus, Ohio 43210 (United States)

2008-09-15T23:59:59.000Z

276

Materials/Condensed Matter  

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

Materials/Condensed Matter Print Materials/Condensed Matter Print Materials research provides the foundation on which the economic well being of our high-tech society rests. The impact of advanced materials ranges dramatically over every aspect of our modern world from the minutiae of daily life to the grand scale of our national economy. Invariably, however, breakthroughs to new technologies trace their origin both to fundamental research in the basic properties of condensed matter and to applied research aimed at manipulating properties (structural, physical, chemical, electrical, magnetic, optical, etc.). Increasingly, the frontiers of materials research include materials that are "strongly correlated," characterized by strong coupling between a material's electrons with other electrons, magnetism, or the material lattice itself. This coupling often results in novel behavior, such as superconductivity, that may lead to technologically important applications.

277

GE Wind Energy Germany | Open Energy Information  

Open Energy Info (EERE)

Jump to: navigation, search Jump to: navigation, search Name GE Wind Energy Germany Place Salzbergen, Germany Zip 48499 Sector Wind energy Product Germany-based, division of GE Wind Energy wind turbine manufacturer and supplier. Coordinates 52.323136°, 7.347278° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":52.323136,"lon":7.347278,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

278

General first law and thermodynamics of horizon/matter systems  

Science Journals Connector (OSTI)

The first law of thermodynamics is derived for bounded, static, spherically symmetric spacetimes which include a matter distribution and either a black-hole or cosmological horizon. Heat capacities associated with horizon/matter systems are calculated. It is found that if the surface area of the boundary is held fixed, the heat capacity of a system including a black hole can always be made positive by including a matter distribution of sufficient density. The heat capacity associated with a system including a cosmological horizon and a matter distribution may be positive or negative depending on the matter configuration, but must always be negative in the limit that the boundary approaches the horizon. A discussion is given of the case in which the cosmological constant is allowed to vary. It is found that the Hawking-Coleman mechanisms for explaining the low value of the cosmological constant are not well defined.

G. Hayward

1991-06-15T23:59:59.000Z

279

Erratum (astro-ph/0510172): Robust Limits on Lorentz Violation from Gamma-Ray Bursts  

E-Print Network [OSTI]

We correct the fitting formula used in refs. [1,2] to obtain a robust limit on a violation of Lorentz invariance that depends linearly on the photon energy. The correction leads to a slight increase of the limit on the scale of the violation, to M > 1.4 x 10^{16} GeV.

John Ellis; N. E. Mavromatos; D. V. Nanopoulos; A. S. Sakharov; E. K. G. Sarkisyan

2007-12-17T23:59:59.000Z

280

Full jet reconstruction in 200 GeV p+p, d+Au and Au+Au collisions by STAR  

E-Print Network [OSTI]

Measurements of inclusive hadron suppression and di-hadron azimuthal correlations have provided important insights into jet quenching in hot QCD matter. However, they do not provide access to the energy of the hard scattering and are limited in their sensitivity since they can be affected by biases toward hard fragmentation and small energy loss. Full jet reconstruction in heavy-ion collisions enables a complete study of the modification of jet structure due to energy loss, but is challenging due to the high multiplicity environment. Study of jet production and properties in d+Au and p+p collisions provides important baseline measurement for jet studies in heavy-ion collisions. We report measurements of fully reconstructed jets in p+p, d+Au and Au+Au collisions at $\\sqrt{s_\\mathrm{NN}} = 200 \\mathrm{GeV}$ from the STAR experiment at RHIC. Measurement of initial state nuclear effects in d+Au collisions utilizing di-jet azimuthal correlations is presented together with similar measurement in p+p collisions. Inclusive jet $\\pt$ spectra and fragmentation functions in p+p and central Au+Au collisions are reported, with subsequent studies of jet nuclear modification factor, jet energy profile and modifications in the fragmentation function due to jet quenching.

Jan Kapitan; for the STAR Collaboration

2009-09-16T23:59:59.000Z

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


281

Tau Portal Dark Matter models at the LHC  

E-Print Network [OSTI]

Motivated by the Galactic Center gamma-ray excess in the Fermi-LAT data, we study the signatures of a class of tau portal dark matter (DM) models where DM particles preferentially couple to tau leptons at the LHC. We consider the constraints from the DM direct detection and investigate the sensitivity of the LHC to di-tau plus missing energy signatures. We find that the LHC with a high luminosity of 3000 fb$^{-1}$ can test the tau portal DM models with fermionic mediators in the mass range of $120\\sim450$ GeV.

Zhao-Huan Yu; Xiao-Jun Bi; Qi-Shu Yan; Peng-Fei Yin

2014-10-13T23:59:59.000Z

282

Crystallization and collapse in relativistically degenerate matter  

SciTech Connect (OSTI)

In this paper, it is shown that a mass density limit exists beyond which the relativistically degenerate matter would crystallize. The mass density limit, found here, is quite analogous to the mass limit predicted by Chandrasekhar for a type of compact stars called white dwarfs (M{sub Ch} Asymptotically-Equal-To 1.43 Solar Mass). In this study, the old problem of white dwarf core collapse, which has been previously investigated by Chandrasekhar using hydrostatic stability criteria, is revisited in the framework of the quantum hydrodynamics model by inspection of the charge screening at atomic scales in the relativistic degeneracy plasma regime taking into account the relativistic Fermi-Dirac statistics and electron interaction features such as the quantum statistical pressure, Coulomb attraction, electron exchange-correlation, and quantum recoil effects. It is revealed that the existence of ion correlation and crystallization of matter in the relativistically degenerate plasma puts a critical mass density limit on white dwarf core region. It is shown that a white dwarf star with a core mass density beyond this critical limit can undergo the spontaneous core collapse (SCC). The SCC phenomenon, which is dominantly caused by the electron quantum recoil effect (interference and localization of the electron wave function), leads to a new exotic state of matter. In such exotic state, the relativistic electron degeneracy can lead the white dwarf crystallized core to undergo the nuclear fusion and an ultimate supernova by means of the volume reduction (due to the enhanced compressibility) and huge energy release (due to the increase in cohesive energy), under the stars huge inward gravitational pressure. Moreover, it is found that the SCC phenomenon is significantly affected by the core composition (it is more probable for heavier plasmas). The critical mass density found here is consistent with the values calculated for core density of typical white dwarf stars.

Akbari-Moghanjoughi, M. [International Centre for Advanced Studies in Physical Sciences and Institute for Theoretical Physics, Ruhr University Bochum, D-44780 Bochum, Germany and Department of Physics, Faculty of Sciences, Azarbaijan Shahid Madani University, 51745-406 Tabriz (Iran, Islamic Republic of)

2013-04-15T23:59:59.000Z

283

Mean free path in nuclear matter from extended Brueckner theory  

Science Journals Connector (OSTI)

The nucleon mean free path in nuclear matter is studied within the framework of the Brueckner-Hartree-Fock approximation extended to incorporate ground-state correlations. The ground state particle-hole excitations give rise to a partial opening of the Fermi sphere and to an enhancement of the mean free path above the Fermi surface. A comparison with the classical limit and the mean free path in neutron matter is discussed along with a simple prescription to include the isospin dependence.

W. Zuo; U. Lombardo; H.-J. Schulze

1998-01-01T23:59:59.000Z

284

Role of nucleation sites on the formation of nanoporous Ge  

SciTech Connect (OSTI)

The role of nucleation sites on the formation of nanoporous Ge was investigated. Three Ge films with different spherical or columnar pore morphologies to act as inherent nucleation sites were sputtered on (001) Ge. Samples were implanted 90 Degree-Sign from incidence at 300 keV with fluences ranging from 3.0 Multiplication-Sign 10{sup 15} to 3.0 Multiplication-Sign 10{sup 16} Ge{sup +}/cm{sup 2}. Electron microscopy investigations revealed varying thresholds for nanoporous Ge formation and exhibited a stark difference in the evolution of the Ge layers based on the microstructure of the initial film. The results suggest that the presence of inherent nucleation sites significantly alters the onset and evolution of nanoporous Ge.

Yates, B. R.; Darby, B. L.; Jones, K. S. [Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611-6400 (United States); Elliman, R. G. [Department of Electronic Materials Engineering, Research School of Physical Sciences and Engineering, Australian National University, Canberra, Australian Capital Territory 0200 (Australia)

2012-09-24T23:59:59.000Z

285

Antihelium from Dark Matter  

E-Print Network [OSTI]

Cosmic-ray anti-nuclei provide a promising discovery channel for the indirect detection of particle dark matter. Hadron showers produced by the pair-annihilation or decay of Galactic dark matter generate anti-nucleons which can in turn form light anti-nuclei. Previous studies have only focused on the spectrum and flux of low energy antideuterons which, although very rarely, are occasionally also produced by cosmic-ray spallation. Heavier elements ($A\\geq3$) have instead entirely negligible astrophysical background and a primary yield from dark matter which could be detectable by future experiments. Using a Monte Carlo event generator and an event-by-event phase space analysis, we compute, for the first time, the production spectrum of \\antihe and \\antiT for dark matter annihilating or decaying to $b\\bar{b}$ and ${W^+}{W^-}$ final states. We then employ a semi-analytic model of interstellar and heliospheric propagation to calculate the \\antihe flux as well as to provide tools to relate the anti-helium spectrum...

Carlson, Eric; Linden, Tim; Profumo, Stefano; Ibarra, Alejandro; Wild, Sebastian

2014-01-01T23:59:59.000Z

286

Antihelium from dark matter  

Science Journals Connector (OSTI)

Cosmic-ray antinuclei provide a promising discovery channel for the indirect detection of particle dark matter. Hadron showers produced by the pair annihilation or decay of Galactic dark matter generate antinucleons which can in turn form light antinuclei. Previous studies have only focused on the spectrum and flux of low energy antideuterons which, although very rarely, are occasionally also produced by cosmic-ray spallation. Heavier elements (A?3) have instead entirely negligible astrophysical background and a primary yield from dark matter which could be detectable by future experiments. Using a MonteCarlo event generator and an event-by-event phase space analysis, we compute, for the first time, the production spectrum of He3 and H3 for dark matter annihilating or decaying to bb and W+W? final states. We then employ a semianalytic model of interstellar and heliospheric propagation to calculate the He3 flux as well as to provide tools to relate the antihelium spectrum corresponding to an arbitrary antideuteron spectrum. Finally, we discuss prospects for current and future experiments, including GAPS and AMS-02.

Eric Carlson; Adam Coogan; Tim Linden; Stefano Profumo; Alejandro Ibarra; Sebastian Wild

2014-04-08T23:59:59.000Z

287

Tunguska Dark Matter Ball  

E-Print Network [OSTI]

It is suggested that the Tunguska event in June 1908 cm-large was due to a cm-large ball of a condensate of bound states of 6 top and 6 anti-top quarks containing highly compressed ordinary matter. Such balls are supposed to make up the dark matter as we earlier proposed. The expected rate of impact of this kind of dark matter ball with the earth seems to crudely match a time scale of 200 years between the impacts. The main explosion of the Tunguska event is explained in our picture as material coming out from deep within the earth, where it has been heated and compressed by the ball penetrating to a depth of several thousand km. Thus the effect has some similarity with volcanic activity as suggested by Kundt. We discuss the possible identification of kimberlite pipes with earlier Tunguska-like events. A discussion of how the dark matter balls may have formed in the early universe is also given.

C. D. Froggatt; H. B. Nielsen

2014-03-27T23:59:59.000Z

288

Tunguska Dark Matter Ball  

E-Print Network [OSTI]

It is suggested that the Tunguska event in June 1908 cm-large was due to a cm-large ball of a condensate of bound states of 6 top and 6 anti-top quarks containing highly compressed ordinary matter. Such balls are supposed to make up the dark matter as we earlier proposed. The expected rate of impact of this kind of dark matter ball with the earth seems to crudely match a time scale of 200 years between the impacts. The main explosion of the Tunguska event is explained in our picture as material coming out from deep within the earth, where it has been heated and compressed by the ball penetrating to a depth of several thousand km. Thus the effect has some similarity with volcanic activity as suggested by Kundt. We discuss the possible identification of kimberlite pipes with earlier Tunguska-like events. A discussion of how the dark matter balls may have formed in the early universe is also given.

Froggatt, C D

2014-01-01T23:59:59.000Z

289

Matter & Energy Nanotechnology  

E-Print Network [OSTI]

to electrical energy in order to power electronic devices, these results point to an advantage in reducingSee Also: Matter & Energy Nanotechnology Materials Science Technology Energy Technology Civil of potential functionalities, ranging from single-nanowire lasers and LEDs to more complex devices

Espinosa, Horacio D.

290

Matter & Energy Nanotechnology  

E-Print Network [OSTI]

See also: Matter & Energy Nanotechnology Civil Engineering Chemistry Computers & Math Computer www.carbodeon.com Nanotechnology afm Perform better live cell research! Non-invasive, in-liquid AFM cures Had flu? You m Science News Share Blog Cite Health & Medicine Mind & Brain Plants & Animals Earth

Espinosa, Horacio D.

291

Matter & Energy Wind Energy  

E-Print Network [OSTI]

See Also: Matter & Energy Wind Energy Energy Technology Physics Nuclear Energy Petroleum 27, 2012) -- Energy flowing from large-scale to small-scale places may be prevented from flowing, indicating that there are energy flows from large to small scale in confined space. Indeed, under a specific

Shepelyansky, Dima

292

Matter & Energy Solar Energy  

E-Print Network [OSTI]

See Also: Matter & Energy Solar Energy· Electronics· Materials Science· Earth & Climate Energy and the Environment · Renewable Energy· Environmental Science · Reference Chemical compound· Semiconductor· Gallium at the University of Illinois, the future of solar energy just got brighter. Although silicon is the industry

Rogers, John A.

293

Matter & Energy Engineering  

E-Print Network [OSTI]

. AmericanEnergyProperties.com Related Stories New Facility BoostsGasHydrates Research (June 2, 2008) --A new & Climate Global Warming Environmental Issues Climate Reference Natural gas Hydrocarbon Automobile emissionsLike 6 0 | More APA MLA See Also: Matter & Energy Petroleum Engineering Fossil Fuels Earth

Sóbester, András

294

Dark matter, not magnetism  

Science Journals Connector (OSTI)

......Astronomical Society. Provided by the NASA Astrophysics Data System 1 March 1993 research-article Letters Dark matter, not magnetism Massimo Persic 1 2 Paolo Salucci 1 1 Notice that most optical rotation curves, coming from the gas-emitted H alpha line......

Massimo Persic; Paolo Salucci

1993-03-01T23:59:59.000Z

295

$?_R$ dark matter-philic Higgs for 3.5 keV X-ray signal  

E-Print Network [OSTI]

We suggest a new model in which a dark matter-philic Higgs is included to discriminate the interaction between dark matter and other particles, to explain the recent observation of the $7~ {\\rm keV}$ X-ray line signal by XMM-Newton observatory. The smallness of the vacuum expectation value of dark matter-philic Higgs can achieve the small mixing angle of the dark matter right-handed neutrino with the ordinary one. We show the range of the symmetry breaking scales as well as the observed dark matter properties are satisfied. In our model, the value of the vacuum expectation value of dark matter-philic Higgs should be about $0.17~ {\\rm GeV}$.

Naoyuki Haba; Hiroyuki Ishida; Ryo Takahashi

2014-08-05T23:59:59.000Z

296

The GeV-TeV Connection in Galactic gamma-ray Sources  

SciTech Connect (OSTI)

Recent observations by atmospheric Cherenkov telescopes such as H.E.S.S. and MAGIC have revealed a large number of new sources of very-high-energy (VHE) gamma-rays above 100 GeV, mostly concentrated along the Galactic plane. At lower energies (100 MeV - 10 GeV) the satellite-based instrument EGRET revealed a population of sources clustering along the Galactic Plane. Given their adjacent energy bands a systematic correlation study between the two source classes seems appropriate. While only a few of the sources connect, both in terms of positional coincidence and spectral consistency, most of the detections occur only in one or the other energy domain. In these cases, for the first time consistent upper limits in the other energy band have been derived. Here, the populations of Galactic sources in both energy domains are characterized on observational as well as on theoretical grounds, followed by an interpretation on their similarities and differences. The observational data at this stage suggest rather different major source populations at GeV and TeV energies. With regards to preparations for the upcoming GLAST mission that will cover the energy range bridging GeV and TeV instruments this paper investigates the connection between the population of sources in these bands and concludes with predictions for commonly observable sources for GLAST-LAT detections.

Funk, S.; /KIPAC, Menlo Park; Reimer, O.; /Stanford U., HEPL /KIPAC, Menlo Park; Torres, Diego F.; /ICREA, Barcelona; Hinton, J.A.; /Leeds U.

2007-09-28T23:59:59.000Z

297

An in situ investigation of Si[sub x]Ge[sub 1-x] chemical vapor deposition by differential reflectance  

SciTech Connect (OSTI)

An investigation of the surface kinetic processes of low pressure chemical vapor deposition (LPCVD) of Si, Ge, and Si[sub x]Ge[sub 1[minus]x] was carried out using time-resolved differential reflectance measurements. The source gas (disilane, digermane, or mixtures of these two diluted in a helium carrier) was delivered to a heated substrate by a fast-acting modulated molecular jet valve. Thin film growth was studied in the range of 400-500[degrees]C on Si and Ge (001) substrates. The kinetics of chemisorption and of by-product desorption were determined from the surface differential reflectance signal obtained using p-polarized, high-stability HeNe probe laser. Both chemisorption and by-product desorption were fond to obey first-order kinetics. Chemisorption of the parent molecules was found to be relatively efficient and weakly temperature dependent. For pure Si and Ge, by-product desorption occurred through a single first-order reaction. Two first-order desorption steps were inferred for the Si[sub x]Ge[sub 1[minus]x] alloy surfaces. These reactions are believed to be H[sub 2] desorption from Si-like and Ge-like surface sites. However, the activation energy of the more rapid of these two steps actually decreases as the Si content of the film increases. Generally, the films were of high crystalline quality and were very well aligned with the substrate. Preferential incorporation of digermane into the film produced an alloy composition that was Ge-rich relative to the gas composition. The primary accomplishment of this work is the demonstration that the active surface layer of the Si[sub x]Ge[sub 1[minus]x] system can be monitored in situ by an optical probe under typical LPCVD conditions. The results indicate that the rate-limiting step in Si or Ge LPCVD obeys simple first-order kinetics. Further work is needed to understand fully the rate-limiting surface reaction in Si[sub x]Ge[sub 1[minus]x] LPCVD.

Sharp, J.W.

1992-01-01T23:59:59.000Z

298

Dark Matter Gravitational Interactions  

E-Print Network [OSTI]

We argue that the conjectured dark mater in the Universe may be endowed with a new kind of gravitational charge that couples to a short range gravitational interaction mediated by a massive vector field. A model is constructed that assimilates this concept into ideas of current inflationary cosmology. The model is also consistent with the observed behaviour of galactic rotation curves according to Newtonian dynamics. The essential idea is that stars composed of ordinary (as opposed to dark matter) experience Newtonian forces due to the presence of an all pervading background of massive gravitationally charged cold dark matter. The novel gravitational interactions are predicted to have a significant influence on pre-inflationary cosmology. The precise details depend on the nature of a gravitational Proca interaction and the description of matter. A gravitational Proca field configuration that gives rise to attractive forces between dark matter charges of like polarity exhibits homogeneous isotropic eternal cosmologies that are free of cosmological curvature singularities thus eliminating the horizon problem associated with the standard big-bang scenario. Such solutions do however admit dense hot pre-inflationary epochs each with a characteristic scale factor that may be correlated with the dark matter density in the current era of expansion. The model is based on a theory in which a modification of Einsteinian gravity at very short distances can be expressed in terms of the gradient of the Einstein metric and the torsion of a non-Riemannian connection on the bundle of linear frames over spacetime. Indeed we demonstrate that the genesis of the model resides in a remarkable simplification that occurs when one analyses the variational equations associated with a broad class of non-Riemannian actions.

R. W. Tucker; C. Wang

1996-12-09T23:59:59.000Z

299

Pion and kaon production in central Pb+Pb collisions at 20A and 30A GeV: Evidence for the onset of deconfinement  

SciTech Connect (OSTI)

Results on charged pion and kaon production in central Pb+Pb collisions at 20A and 30A GeV are presented and compared to data at lower and higher energies. Around 30A GeV a rapid change of the energy dependence for the yields of pions and kaons as well as for the shape of the transverse mass spectra is observed. The change is compatible with the prediction that the threshold for production of a state of deconfined matter at the early stage of the collisions is located at low CERN Super Proton Synchroton energies.

Alt, C.; Blume, C.; Dinkelaker, P.; Flierl, D.; Kliemant, M.; Kniege, S.; Kollegger, T.; Lungwitz, B.; Mitrovski, M.; Renfordt, R.; Schuster, T.; Stock, R.; Strabel, C.; Stroebele, H.; Wetzler, A. [Fachbereich Physik der Universitaet, Frankfurt (Germany); Anticic, T.; Kadija, K.; Nicolic, V.; Susa, T. [Rudjer Boskovic Institute, Zagreb (Croatia); Baatar, B. [Joint Institute for Nuclear Research, Dubna (Russian Federation)] (and others)

2008-02-15T23:59:59.000Z

300

Suppression of Ge-O And Ge-N Bonding at Ge-HfO(2) And Ge-TiO(2) Interfaces By Deposition Onto Plasma-Nitrided Passivated Ge Substrates: Integration Issues Ge Gate Stacks Into Advanced Devices  

SciTech Connect (OSTI)

A study of changes in nano-scale morphology of thin films of nano-crystalline transition metal (TM) elemental oxides, HfO{sub 2} and TiO{sub 2}, on plasma-nitrided Ge(100) substrates, and Si(100) substrates with ultra-thin (-0.8 nm) plasma-nitrided Si suboxide, SiO{sub x}, x < 2, or SiON interfacial layers is presented. Near edge X-ray absorption spectroscopy (NEXAS) has been used to determine nano-scale morphology of these films by Jahn-Teller distortion removal of band edge d-state degeneracies. These results identify a new and novel application for NEXAS based on the resonant character of the respective O K{sub 1} and N K{sub 1} edge absorptions. This paper also includes a brief discussion of the integration issues for the introduction of this Ge breakthrough into advanced semiconductor circuits and systems. This includes a comparison of nano-crystalline and non-crystalline dielectrics, as well as issues relative to metal gates.

Lee, S.; Long, J.P.; Lucovsky, G.; Whitten, J.; Seo, H.; Luning, J.

2009-05-19T23:59:59.000Z

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


301

Energy Matters in Washington State Page 1 Energy Matters  

E-Print Network [OSTI]

Energy Matters in Washington State ­ Page 1 Energy Matters in Washington State June 2008 Updated November 2009 Updated and Revised October 2013 Grand Coulee Dam #12;Energy Matters in Washington State ­ Page 2 Copyright © 2013 Washington State University Energy Program. 905 Plum Street SE, P.O. Box 43169

Collins, Gary S.

302

LANSCE beam current limiter  

SciTech Connect (OSTI)

The Radiation Security System (RSS) at the Los Alamos Neutron Science Center (LANSCE) provides personnel protection from prompt radiation due to accelerated beam. Active instrumentation, such as the Beam Current Limiter, is a component of the RSS. The current limiter is designed to limit the average current in a beam line below a specific level, thus minimizing the maximum current available for a beam spill accident. The beam current limiter is a self-contained, electrically isolated toroidal beam transformer which continuously monitors beam current. It is designed as fail-safe instrumentation. The design philosophy, hardware design, operation, and limitations of the device are described.

Gallegos, F.R.

1996-06-01T23:59:59.000Z

303

The Search for Dark Matter  

ScienceCinema (OSTI)

More than 25 years ago, PNNL scientists began the first underground measurements searching for dark matter using specialized radiation detector technology. Dark matter is yet to be discovered says Physicist John L. Orrell.

Orrell, John

2014-07-24T23:59:59.000Z

304

The Search for Dark Matter  

SciTech Connect (OSTI)

More than 25 years ago, PNNL scientists began the first underground measurements searching for dark matter using specialized radiation detector technology. Dark matter is yet to be discovered says Physicist John L. Orrell.

Orrell, John

2013-11-20T23:59:59.000Z

305

Quantum Condensed Matter | More Science | ORNL  

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

Quantum Condensed Matter SHARE Quantum Condensed Matter Neutron scattering is a uniquely powerful probe for measuring the structure and dynamics of condensed matter. As such it is...

306

Quantum Condensed Matter | Neutron Science | ORNL  

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

Quantum Condensed Matter SHARE Quantum Condensed Matter Neutron scattering is a uniquely powerful probe for measuring the structure and dynamics of condensed matter. As such it is...

307

Interface and nanostructure evolution of cobalt germanides on Ge(001)  

SciTech Connect (OSTI)

Cobalt germanide (Co{sub x}Ge{sub y}) is a candidate system for low resistance contact modules in future Ge devices in Si-based micro and nanoelectronics. In this paper, we present a detailed structural, morphological, and compositional study on Co{sub x}Ge{sub y} formation on Ge(001) at room temperature metal deposition and subsequent annealing. Scanning tunneling microscopy and low energy electron diffraction clearly demonstrate that room temperature deposition of approximately four monolayers of Co on Ge(001) results in the Volmer Weber growth mode, while subsequent thermal annealing leads to the formation of a Co-germanide continuous wetting layer which evolves gradually towards the growth of elongated Co{sub x}Ge{sub y} nanostructures. Two types of Co{sub x}Ge{sub y} nanostructures, namely, flattop- and ridge-type, were observed and a systematic study on their evolution as a function of temperature is presented. Additional transmission electron microscopy and x-ray photoemission spectroscopy measurements allowed us to monitor the reaction between Co and Ge in the formation process of the Co{sub x}Ge{sub y} continuous wetting layer as well as the Co{sub x}Ge{sub y} nanostructures.

Grzela, T., E-mail: grzela@ihp-microelectronics.com; Schubert, M. A. [IHP, Im Technologiepark 25, 15236 Frankfurt (Oder) (Germany); Koczorowski, W. [London Centre for Nanotechnology, University College London, 17-19 Gordon Street, London, WC1H 0AH,United Kingdom (United Kingdom); Institute of Physics, Poznan University of Technology, Nieszawska 13A, 60-965 Poznan (Poland); Capellini, G. [IHP, Im Technologiepark 25, 15236 Frankfurt (Oder) (Germany); Dipartimento di Scienze, Universit degli Studi Roma Tre, I-00146 Roma (Italy); Czajka, R. [Institute of Physics, Poznan University of Technology, Nieszawska 13A, 60-965 Poznan (Poland); Radny, M. W. [Institute of Physics, Poznan University of Technology, Nieszawska 13A, 60-965 Poznan (Poland); School of Mathematical and Physical Sciences, The University of Newcastle, University Drive, Callaghan NSW, 2308 (Australia); Curson, N.; Schofield, S. R. [London Centre for Nanotechnology, University College London, 17-19 Gordon Street, London, WC1H 0AH,United Kingdom (United Kingdom); Schroeder, T. [IHP, Im Technologiepark 25, 15236 Frankfurt (Oder) (Germany); BTU Cottbus, Konrad-Zuse Str. 1, 03046 Cottbus (Germany)

2014-02-21T23:59:59.000Z

308

Direct search for dark matter  

SciTech Connect (OSTI)

Dark matter is hypothetical matter which does not interact with electromagnetic radiation. The existence of dark matter is only inferred from gravitational effects of astrophysical observations to explain the missing mass component of the Universe. Weakly Interacting Massive Particles are currently the most popular candidate to explain the missing mass component. I review the current status of experimental searches of dark matter through direct detection using terrestrial detectors.

Yoo, Jonghee; /Fermilab

2009-12-01T23:59:59.000Z

309

Confusing the extragalactic neutrino flux limit with a neutrino propagation limit  

SciTech Connect (OSTI)

We study the possible suppression of the extragalactic neutrino flux due to a nonstandard interaction during its propagation. In particular, we study neutrino interaction with an ultra-light scalar field dark matter. It is shown that the extragalactic neutrino flux may be suppressed by such an interaction, leading to a new mechanism to reduce the ultra-high energy neutrino flux. We study both the cases of non-self-conjugate as well as self-conjugate dark matter. In the first case, the suppression is independent of the neutrino and dark matter masses. We conclude that care must be taken when explaining limits on the neutrino flux through source acceleration mechanisms only, since there could be other mechanisms for the reduction of the neutrino flux.

Barranco, Juan [Instituto de Astronoma, Universidad Nacional Autonoma de Mxico, Mexico, DF 04510 (Mexico); Miranda, Omar G. [Departamento de Fsica, Centro de Investigacin y de Estudios Avanzados del IPN, Apdo. Postal 14-740 07000 Mxico, D.F. (Mexico); Moura, Celio A. [Centro de Cincias Naturais e Humanas, Universidade Federal do ABC, Rua Santa Adlia, 166, 09210-170 Santo Andr, SP (Brazil); Rashba, Timur I. [Max-Planck-Institute for Solar System Research, Katlenburg-Lindau, 37191 (Germany); Rossi-Torres, Fernando, E-mail: barranco@astroscu.unam.mx, E-mail: Omar.Miranda@fis.cinvestav.mx, E-mail: celio.moura@ufabc.edu.br, E-mail: timur@mppmu.mpg.de, E-mail: ftorres@ifi.unicamp.br [Instituto de Fsica Terica, Universidade Estadual Paulista, Rua Dr. Bento Teobaldo Ferraz, 271 - Bl. II, 01140-070, So Paulo, SP (Brazil)

2011-10-01T23:59:59.000Z

310

Particulate matter dynamics  

E-Print Network [OSTI]

A substantial fraction of the particulate matter released into the atmosphere by industrial or natural processes corresponds to particles whose aerodynamic diameters are greater than 50 mm. It has been shown that, for these particles, the classical description of Gaussian plume diffusion processes, is inadequate to describe the transport and deposition. In this paper we present new results concerning the dispersion of coarse particulate matter. The simulations are done with our own code that uses the Bulirsch Stoer numerical integrator to calculate threedimensional trajectories of particles released into the environment under very general conditions. Turbulent processes are simulated by the Langevin equation and weather conditions are modeled after stable (Monin-Obukhov length L> 0) and unstable conditions (L <0). We present several case studies based on Monte Carlo simulations and discusses the effect of weather on the final deposition of these particles.

Cionco, Rodolfo G; Caligaris, Marta G

2012-01-01T23:59:59.000Z

311

Brookhaven Condensed Matter Physics  

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

Condensed Matter Physics Condensed Matter Physics Condensed matter physicists study the properties of bulk matter-solids and liquids-as well as the properties exhibited at surfaces and interfaces, with a view to obtaining a fundamental understanding of the unusual properties that materials can exhibit. These problems are some of the most challenging in physics today, but have the huge pay-off in that such an understanding may ultimately lead to improved materials for use in applications as diverse as computing, memory storage, electric motors, and energy storage and transport. At Brookhaven Lab, this work includes both experimental and theoretical studies. Much of the experimental work carried out today uses the National Synchrotron Light Source (NSLS, shown at right)-one of the premiere synchrotron light sources of the last two decades. Commissioned in the 1980s, the NSLS is host to more than 2,200 users per year and produces copious amounts of light, from the infrared to the ultraviolet to the x-ray. By using this light as a probe, scientists can learn about the arrangement of the atoms and electrons in the materials and how they behave under various conditions. Among other projects, BNL scientists have played leading roles in the development and application of resonant and inelastic x-ray scattering techniques to the study of magnetic and other materials, have pioneered the use of photoemission techniques (based on the photoelectric effect that Einstein first understood 100 years ago) for looking at electronic and magnetic materials, and have carried out some of the seminal experiments to understand the atomic and magnetic structure at surfaces.

312

Directional detection of dark matter streams  

Science Journals Connector (OSTI)

Directional detection of weakly interacting massive particles, in which the energies and directions of the recoiling nuclei are measured, currently presents the only prospect for probing the local velocity distribution of Galactic dark matter. We investigate the extent to which future directional detectors would be capable of probing dark matter substructure in the form of streams. We analyze the signal expected from a Sagittarius-like stream and also explore the full parameter space of stream speed, direction, dispersion and density. Using a combination of nonparametric directional statistics, a profile likelihood ratio test and Bayesian parameter inference we find that within acceptable exposure times [O(10)??kg?yr for cross sections just below the current exclusion limits] future directional detectors will be sensitive to a wide range of stream velocities and densities. We also examine and discuss the importance of the energy window of the detector.

Ciaran A.?J. OHare and Anne M. Green

2014-12-08T23:59:59.000Z

313

Symmetry energy coefficients for asymmetric nuclear matter  

E-Print Network [OSTI]

Symmetry energy coefficients of asymmetric nuclear matter are investigated as the inverse of nuclear matter polarizabilities with two different approaches. Firstly a general calculation shows they may depend on the neutron-proton asymmetry itself. The choice of particular prescriptions for the density fluctuations lead to certain isospin (n-p asymmetry) dependences of the polarizabilities. Secondly, with Skyrme type interactions, the static limit of the dynamical polarizability is investigated corresponding to the inverse symmetry energy coefficient which assumes different values at different asymmetries (and densities and temperatures). The symmetry energy coefficient (in the isovector channel) is found to increase as n-p asymmetries increase. The spin symmetry energy coefficient is also briefly investigated.

Fbio L. Braghin

2003-12-16T23:59:59.000Z

314

GE Uses DOE Advanced Light Sources to Develop Revolutionary Battery  

Office of Science (SC) Website

GE Uses DOE Advanced Light Sources to Develop GE Uses DOE Advanced Light Sources to Develop Revolutionary Battery Technology Discovery & Innovation Stories of Discovery & Innovation Brief Science Highlights SBIR/STTR Highlights Contact Information Office of Science U.S. Department of Energy 1000 Independence Ave., SW Washington, DC 20585 P: (202) 586-5430 06.13.11 GE Uses DOE Advanced Light Sources to Develop Revolutionary Battery Technology Company is constructing a new battery factory in Upstate New York that is expected to create 300+ jobs. Print Text Size: A A A Subscribe FeedbackShare Page Click to enlarge photo. Enlarge Photo GE's new Image courtesy of GE GE's new "Durathon(tm)" sodium metal halide battery. The story of American manufacturing over the past two decades has too often been a tale of outsourcing, off-shoring, and downsizing-not least in

315

ber die Thalliumgermanate Tl2Ge4O9 und Tl2Ge6O13  

Science Journals Connector (OSTI)

Nach Dehydratation des Germanat-Zeoliths Tl3HGe7O16 4 H2O bildet sich bei 650C das zu Me2Ge4O9 (Me=Na, K, Rb) isotype Thalliumtetragermanat. Durch Entwsserung bei 700C entsteht aus dem Zeolith ein stabiles ...

Penelope Papamantellos; A. Wittmann

1962-01-01T23:59:59.000Z

316

Limited Test Ban Treaty  

National Nuclear Security Administration (NNSA)

Detection System (USNDS), which monitors compliance with the international Limited Test Ban Treaty (LTBT). The LTBT, signed by 108 countries, prohibits nuclear testing in the...

317

SHIELDING ESTIMATES FOR THE ANL 6.0 GeV SYNCHROTRON LIGHT SOURCE  

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

SHIELDING ESTIMATES FOR THE ANL 6.0 GeV SHIELDING ESTIMATES FOR THE ANL 6.0 GeV SYNCHROTRON LIGHT SOURCE H. J. Moe V. R. Veluri LS-55-Revised Harch 1987 2 1.0 Introduction Shielding estimates for the linac, positron converter, booster synchrotron and the positron storage ring have been computed using preliminary design information. Calculations have been made of the resulting radiation for several types of operations involving normal beam loss, as well as, certain accidental beam losses. When available, experimental data from existing accelerator and light source facilities have been used in lieu of theoretical estimates. 2.0 Shielding Design Objective The Department of Energy's basic occupational exposure limit is 5 rem per year (DOE 81). However, in its guidance for maintaining exposures "as

318

GE Wind Energy | Open Energy Information  

Open Energy Info (EERE)

Wind Energy Wind Energy Jump to: navigation, search Name GE Wind Energy Place Atlanta, Georgia Zip GA 30339 Sector Wind energy Product GE's wind energy division, formed as a result of the purchase of almost all of Enron Wind Corporation's assets. Provides power plant design, engineering and site selection, as well as operation and maintenance. Coordinates 33.748315°, -84.391109° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":33.748315,"lon":-84.391109,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

319

Neutron electric form factor up to Q{sup 2} = 1.47 GeV/c{sup 2}  

SciTech Connect (OSTI)

The ratio of the electric to the magnetic form factor of the neutron, g /equiv G{sub En}/G{sub Mn} , was measured via recoil polarimetry (R.G. Arnold, C.E. Carlson, F. Gross, Phys. Rev. C 23, 363 (1981)) from the quasielastic {sup 2}H (/mathop(e)/limitse' /mathop(n)/limits) 1H reaction at three values of Q{sup 2} (viz, 0.45, 1.15, and 1.47 (GeV/c){sup 2}) in Hall C of the Thomas Jefferson National Accelerator Facility. The data reveal that GEn continues to follow the Galster parameterization up to Q{sup 2} = 1.15 (GeV/c){sup 2} and rises above the Galster parameterization at Q{sup 2} = 1.47 (GeV/c){sup 2}.

Richard Madey; Andrei Semenov; S. Taylor; Aram Aghalaryan; Erick Crouse; Glen MacLachlan; Bradley Plaster; Shigeyuki Tajima; William Tireman; Chenyu Yan; Abdellah Ahmidouch; Brian Anderson; Hartmuth Arenhovel; Razmik Asaturyan; O. Baker; Alan Baldwin; Herbert Breuer; Roger Carlini; E Christy; Steve Churchwell; Leon Cole; Areg Danagoulian; Donal Day; Mostafa Elaasar; Rolf Ent; Manouchehr Farkhondeh; Howard Fenker; John Finn; Liping Gan; Kenneth Garrow; Paul Gueye; Calvin Howell; Bitao Hu; Mark Jones; James Kelly; Cynthia Keppel; Mahbubul Khandaker; Wooyoung Kim; Stanley Kowalski; Allison Lung; David Mack; D. Manley; Pete Markowitz; Joseph Mitchell; Hamlet Mkrtchyan; Allena Opper; Charles Perdrisat; Vina Punjabi; Brian Raue; Tilmann Reichelt; Joerg Reinhold; Julie Roche; Yoshinori Sato; Irina Semenova; Wonick Seo; Neven Simicevic; G. Smith; Samuel Stepanyan; Vardan Tadevosyan; Liguang Tang; Paul Ulmer; William Vulcan; J. W. Watson; Steven Wells; Frank Wesselmann; Stephen Wood; Chen Yan; Seunghoon Yang; Lulin Yuan; Wei-Ming Zhang; Hong Guo Zhu; Xiaofeng Zhu

2003-07-15T23:59:59.000Z

320

Messungen derK-Konversionskoeffizienten und der Aktivierungsquerschnitte der isomeren Atomkerne Se77m , Se79m , Ge75m und Ge77m  

Science Journals Connector (OSTI)

TheK-conversion coefficients ? K of the nuclear isomers Se77m , Se79m , Ge75m and Ge77m have been measured by d...

Hermann Weigmann

1962-01-01T23:59:59.000Z

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


321

Constraining the nuclear matter equation of state around twice saturation density  

E-Print Network [OSTI]

Using FOPI data on elliptic flow in Au+Au collisions between 0.4 and 1.5A GeV we extract constraints for the equation of state (EOS) of compressed symmetric nuclear matter using the transport code IQMD by introducing an observable describing the evolution of the size of the elliptic flow as a function of rapidity. This observable is sensitive to the nuclear EOS and a robust tool to constrain the compressibility of nuclear matter up to 2 $\\rho_0$.

Fvre, A Le; Reisdorf, W; Aichelin, J; Hartnack, Ch

2015-01-01T23:59:59.000Z

322

Closing the window on strongly interacting dark matter with IceCube  

Science Journals Connector (OSTI)

We use the recent results on dark matter searches of the 22-string IceCube detector to probe the remaining allowed window for strongly interacting dark matter in the mass range 104GeV. We calculate the expected signal in the 22-string IceCube detector from the annihilation of such particles captured in the Sun and compare it to the detected background. As a result, the remaining allowed region in the mass versus cross section parameter space is ruled out. We also show the expected sensitivity of the complete IceCube detector with 86 strings.

Ivone F. M. Albuquerque and Carlos Prez de los Heros

2010-03-08T23:59:59.000Z

323

In Wino Veritas? Indirect Searches Shed Light on Neutralino Dark Matter  

E-Print Network [OSTI]

Indirect detection constraints on gamma rays (both continuum and lines) have set strong constraints on wino dark matter. By combining results from Fermi-LAT and HESS, we show that: light nonthermal wino dark matter is strongly excluded; thermal wino dark matter is allowed only if the Milky Way dark matter distribution has a significant (>~0.4 kpc) core; and for plausible NFW and Einasto distributions the entire range of wino masses from 100 GeV up to 3 TeV can be excluded. The case of light, nonthermal wino dark matter is particularly interesting in scenarios with decaying moduli that reheat the universe to a low temperature. Typically such models have been discussed for low reheating temperatures, not far above the BBN bound of a few MeV. We show that constraints on the allowed wino relic density push such models to higher reheating temperatures and hence heavier moduli. Even for a flattened halo model consisting of an NFW profile with constant-density core inside 1 kpc and a density near the sun of 0.3 GeV/...

Fan, JiJi

2013-01-01T23:59:59.000Z

324

Biofuel Research at Brazil Center of Excellence | GE Global Research  

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

do texto. Aproveitem. A misso do centro de excelncia de biocombustves da GE do Brasil aumentar a capacidade local de fornecer tecnologia na produo de biocombustves...

325

Meeting Energy Needs in Brazil |GE Global Research  

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

Brazil Looking a Decade Ahead: Electrical Power Generation in Brazil Ricardo Hernandez Pereira 2014.11.03 In the Bioenergy Systems Organization at GE Global Research - Rio de...

326

GE Technology to Help Canada Province Meet Growing Energy Needs  

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

funding and collaboration models at its European Global Research Center near Munich, Germany. Mark Little, GE's Senior Vice President and Chief Technology Officer, and thought...

327

Governor Cuomo, GE Announce Power Electronics Manufacturing Consortium  

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

Governor Cuomo Announces 100 Businesses Led by GE to Join 500 Million Partnership with State to Develop Next-Generation Power Electronics, Creating Thousands of Jobs in Capital...

328

Technology makes reds "pop" in LED displays | GE Global Research  

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

Televisions Research breakthrough will vastly improve color and crispness of images on LED devices NISKAYUNA, NY, July, 24, 2014 - GE announced today a research breakthrough that...

329

Titan propels GE wind turbine research into new territory | ornl...  

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

Titan propels GE wind turbine research into new territory January 17, 2014 The amount of global electricity supplied by wind, the world's fastest growing energy source, is expected...

330

Heteroepitaxial Ge-on-Si by DC magnetron sputtering  

SciTech Connect (OSTI)

The growth of Ge on Si(100) by DC Magnetron Sputtering at various temperatures is studied by Spectroscopic Ellipsometry and Transmission Electron Microscopy. Smooth heteroepitaxial Ge films are prepared at relatively low temperatures of 380C. Typical Stransky-Krastanov growth is observed at 410C. At lower temperatures (320C), films are essentially amorphous with isolated nanocrystallites at the Si-Ge interface. A minor oxygen contamination at the interface, developing after ex-situ oxide removal, is not seen to hinder epitaxy. Compensation of dislocation-induced acceptors in Ge by sputtering from n-doped targets is proposed.

Steglich, Martin; Schrempel, Frank; Fchsel, Kevin; Kley, Ernst-Bernhard [Institute of Applied Physics, Abbe Center of Photonics, Friedrich Schiller University, Albert-Einstein-Strae 15, 07745 Jena (Germany)] [Institute of Applied Physics, Abbe Center of Photonics, Friedrich Schiller University, Albert-Einstein-Strae 15, 07745 Jena (Germany); Patzig, Christian; Berthold, Lutz; Hche, Thomas [Fraunhofer Institute for Mechanics of Materials IWM, Walter-Hlse-Strae 1, 06120 Halle (Germany)] [Fraunhofer Institute for Mechanics of Materials IWM, Walter-Hlse-Strae 1, 06120 Halle (Germany); Tnnermann, Andreas [Institute of Applied Physics, Abbe Center of Photonics, Friedrich Schiller University, Albert-Einstein-Strae 15, 07745 Jena (Germany) [Institute of Applied Physics, Abbe Center of Photonics, Friedrich Schiller University, Albert-Einstein-Strae 15, 07745 Jena (Germany); Fraunhofer Institute for Applied Optics and Precision Engineering IOF, Albert-Einstein-Str. 7, 07745 Jena (Germany)

2013-07-15T23:59:59.000Z

331

J/{psi} Production in {radical}(s{sub NN})=200 GeV Cu+Cu Collisions  

SciTech Connect (OSTI)

Yields for J/{psi} production in Cu+Cu collisions at {radical}(s{sub NN})=200 GeV have been measured over the rapidity range |y|<2.2 and compared with results in p+p and Au+Au collisions at the same energy. The Cu+Cu data offer greatly improved precision over existing Au+Au data for J/{psi} production in collisions with small to intermediate numbers of participants, in the range where the quark-gluon plasma transition threshold is predicted to lie. Cold nuclear matter estimates based on ad hoc fits to d+Au data describe the Cu+Cu data up to N{sub part}{approx}50, corresponding to a Bjorken energy density of at least 1.5 GeV/fm{sup 3}.

Adare, A.; Bickley, A. A.; Ellinghaus, F.; Glenn, A.; Kinney, E.; Nagle, J. L.; Seele, J.; Wysocki, M. [University of Colorado, Boulder, Colorado 80309 (United States); Afanasiev, S.; Isupov, A.; Litvinenko, A.; Malakhov, A.; Peresedov, V.; Rukoyatkin, P.; Zolin, L. [Joint Institute for Nuclear Research, 141980 Dubna, Moscow Region (Russian Federation); Aidala, C.; Chi, C. Y.; Cole, B. A.; D'Enterria, D.; Jia, J. [Columbia University, New York, New York 10027 and Nevis Laboratories, Irvington, New York 10533 (United States)] (and others)

2008-09-19T23:59:59.000Z

332

Scaling Properties of Hyperon Production in Au + Au Collisions at sqrt sNN = 200 GeV  

SciTech Connect (OSTI)

We present the scaling properties of Lambda, Xi, and their anti-particles produced at mid-rapidity in Au+Au collisions at RHIC at psNN = 200 GeV. The yield of multi-strange baryons per participant nucleon increases from peripheral to central collisions more rapidly than the Lambda yield, which appears to correspond to an increasing strange quark density of matter produced. The value of the strange phase space occupancy factor gamma s, obtained from a thermal model fit to the data, approaches unity for the most central collisions. We also show that the nuclear modification factors, RCP, of Lambda and Xi are consistent with each other and with that of protons in the transverse momentum range2.0< pT< 5.0 GeV/c. This scaling behaviour is consistent with a scenario of hadron formation from constituent quark degrees of freedom through quark recombination or coalescence.

Adams, J.

2006-06-08T23:59:59.000Z

333

Limits to the muon flux from neutralino annihilations in the Sun with the AMANDA detector  

E-Print Network [OSTI]

A search for an excess of muon-neutrinos from neutralino annihilations in the Sun has been performed with the AMANDA-II neutrino detector using data collected in 143.7 days of live-time in 2001. No excess over the expected atmospheric neutrino background has been observed. An upper limit at 90% confidence level has been obtained on the annihilation rate of captured neutralinos in the Sun, as well as the corresponding muon flux limit at the Earth, both as functions of the neutralino mass in the range 100 GeV-5000 GeV.

The AMANDA collaboration; M. Ackermann

2005-08-24T23:59:59.000Z

334

Symmetry Energy I: Semi-Infinite Matter  

E-Print Network [OSTI]

Energy for a nucleus is considered in macroscopic limit, in terms of nucleon numbers. Further considered for a nuclear system is the Hohenberg-Kohn energy functional, in terms of proton and neutron densities. Finally, Skyrme-Hartree-Fock calculations are carried out for a half-infinite particle-stable nuclear-matter. In each case, the attention is focused on the role of neutron-proton asymmetry and on the nuclear symmetry energy. We extend the considerations on the symmetry term from an energy formula to the respective term in the Hohenberg-Kohn functional. We show, in particular, that in the limit of an analytic functional, and subject to possible Coulomb corrections, it is possible to construct isoscalar and isovector densities out of the proton and neutron densities, that retain a universal relation to each other, approximately independent of asymmetry. In the so-called local approximation, the isovector density is inversely proportional to the symmetry energy in uniform matter at the local isoscalar density. Generalized symmetry coefficient of a nuclear system is related, in the analytic limit of a functional, to an integral of the isovector density. We test the relations, inferred from the Hohenberg-Kohn functional, in the Skyrme-Hartree-Fock calculations of half-infinite matter. Within the calculations, we obtain surface symmetry coefficients and parameters characterizing the densities, for the majority of Skyrme parameterizations proposed in the literature. The volume-to-surface symmetry-coefficient ratio and the displacement of nuclear isovector relative to isoscalar surfaces both strongly increase as the slope of symmetry energy in the vicinity of normal density increases.

Pawel Danielewicz; Jenny Lee

2008-07-23T23:59:59.000Z

335

Structural and optical properties of GaAs-based heterostructures with Ge and Ge/InGaAs quantum wells  

SciTech Connect (OSTI)

GaAs-based heterostructures with Ge and Ge/InGaAs quantum wells are grown by laser-assisted sputtering. Structural and optical studies of the heterostructures are carried out. A broad photoluminescence line is observed in the wavelength range from 1300 to 1650 nm. The line corresponds to indirect transitions in the momentum space of the Ge quantum wells and to transitions between the In{sub 0.28}Ga{sub 0.72}As and Ge layers, indirect in coordinate space, but direct in momentum space.

Aleshkin, V. Ya.; Dubinov, A. A., E-mail: sanya@ipm.sci-nnov.ru; Drozdov, M. N. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation); Zvonkov, B. N. [Nizhni Novgorod State University, Research Physical Technical Institute (Russian Federation); Kudryavtsev, K. E.; Tonkikh, A. A.; Yablonskiy, A. N. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation); Werner, P. [Max Planck Institute of Microstructure Physics (Germany)

2013-05-15T23:59:59.000Z

336

Effect of Ge-composition on the Gain of a Thin Layer Si 1-y Ge y Avalanche Photodiode  

Science Journals Connector (OSTI)

Gain calculation of Si 1-y Ge y n+-i-p+...avalanche photodiode (APD) is described for multiplication layer down to tens of nanometers c...

Kanishka Majumder; N. R. Das

2014-01-01T23:59:59.000Z

337

Constraints on dark matter annihilation from AMS-02 results  

Science Journals Connector (OSTI)

We use recently released data on the positron-to-electron ratio in cosmic rays from the AMS-02 experiment to constrain dark matter annihilation in the MilkyWay. Due to the yet unexplained positron excess, limits are generally weaker than those obtained using other probes, especially gamma rays. This also means that explaining the positron excess in terms of dark matter annihilation is difficult. Only if very conservative assumptions on the dark matter distribution in the Galactic center region are adopted, it may be possible to accommodate dark matter annihilating to leptons with a cross section above 10-24??cm3/sec?. We comment on several theoretical mechanisms to explain such large annihilation cross sections.

Joachim Kopp

2013-10-24T23:59:59.000Z

338

Asymmetric Nuclear Matter in the Relativistic Brueckner Hartree Fock approach  

E-Print Network [OSTI]

We present a calculation of asymmetric nuclear matter properties in a relativistic Brueckner Hartree Fock framework. Following other calculations the components of the self-energies are extracted by projecting on Lorentz invariant amplitudes. It is shown that for asymmetric nuclear matter one needs a sixth invariant. We present a set of invariants which in the limit of symmetric nuclear matter reduces to the conventional set. We argue that the existence of such a properly behaving set is also crucial for the application of the projection method in symmetric nuclear matter. Results for the equation of state and other observables are presented. Special attention is payed to an analysis in terms of mean-field effective coupling constants. Apart from the usual ones we also find significant strength in the isovector scalar channel, which can be interpreted as an effective $\\delta$-meson.

F. de Jong; H. Lenske

1997-07-14T23:59:59.000Z

339

Dark Matter Constraints from a Cosmic Index of Refraction  

E-Print Network [OSTI]

The dark-matter candidates of particle physics invariably possess electromagnetic interactions, if only via quantum fluctuations. Taken en masse, dark matter can thus engender an index of refraction which deviates from its vacuum value. Its presence is signaled through frequency-dependent effects: the real part yields dispersive effects in propagation, and the imaginary part yields such in attenuation. We discuss theoretical constraints on the expansion of the index of refraction with frequency, the physical interpretation of the terms, and the particular observations needed to isolate its coefficients. This, with the advent of new opportunities to view gamma-ray bursts at cosmological distance scales, gives us a new probe of dark matter. As a first application we use the time delay determined from radio afterglow observations of gamma-ray bursts to limit the charge-to-mass ratio of dark matter to |\\epsilon/M|< 1.8 x 10^{-5}/eV at 95% CL.

Gardner, S

2009-01-01T23:59:59.000Z

340

Constraining warm dark matter with cosmic shear power spectra  

SciTech Connect (OSTI)

We investigate potential constraints from cosmic shear on the dark matter particle mass, assuming all dark matter is made up of light thermal relic particles. Given the theoretical uncertainties involved in making cosmological predictions in such warm dark matter scenarios we use analytical fits to linear warm dark matter power spectra and compare (i) the halo model using a mass function evaluated from these linear power spectra and (ii) an analytical fit to the non-linear evolution of the linear power spectra. We optimistically ignore the competing effect of baryons for this work. We find approach (ii) to be conservative compared to approach (i). We evaluate cosmological constraints using these methods, marginalising over four other cosmological parameters. Using the more conservative method we find that a Euclid-like weak lensing survey together with constraints from the Planck cosmic microwave background mission primary anisotropies could achieve a lower limit on the particle mass of 2.5 keV.

Markovic, Katarina; Weller, Jochen [University Observatory Munich, Ludwig-Maximilian University, Scheinerstr. 1, 81679 Munich (Germany); Bridle, Sarah [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Slosar, Ane, E-mail: markovic@usm.lmu.de, E-mail: sarah.bridle@ucl.ac.uk, E-mail: anze@bnl.gov, E-mail: jochen.weller@usm.lmu.de [Brookhaven National Laboratory, Building 510A, Upton, NY 11973-5000 (United States)

2011-01-01T23:59:59.000Z

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


341

Particle production at high baryon density in central Au+Au reactions at 11.6A GeV/c  

Science Journals Connector (OSTI)

Semi-inclusive proton and pion distributions from central Au+Au reactions at 11.6A GeV/c have been measured. The proton rapidity distribution shows significantly increased stopping compared to lighter systems, providing strong evidence for the formation of a state of matter with baryon density substantially greater than normal nuclear matter. Unlike reactions at this energy induced by lighter heavy ions, at low mt-m0 the proton invariant spectra deviate from a single exponential shape and become flatter, while ?- spectra are found to rise faster than the ?+ spectra.

L. Ahle et al. ((E-802 Collaboration))

1998-02-01T23:59:59.000Z

342

Neutrino constraints on the dark matter total annihilation cross section  

SciTech Connect (OSTI)

In the indirect detection of dark matter through its annihilation products, the signals depend on the square of the dark matter density, making precise knowledge of the distribution of dark matter in the Universe critical for robust predictions. Many studies have focused on regions where the dark matter density is greatest, e.g., the galactic center, as well as on the cosmic signal arising from all halos in the Universe. We focus on the signal arising from the whole Milky Way halo; this is less sensitive to uncertainties in the dark matter distribution, and especially for flatter profiles, this halo signal is larger than the cosmic signal. We illustrate this by considering a dark matter model in which the principal annihilation products are neutrinos. Since neutrinos are the least detectable standard model particles, a limit on their flux conservatively bounds the dark matter total self-annihilation cross section from above. By using the Milky Way halo signal, we show that previous constraints using the cosmic signal can be improved on by 1-2 orders of magnitude; dedicated experimental analyses should be able to improve both by an additional 1-2 orders of magnitude.

Yueksel, Hasan [Department of Physics, Ohio State University, Columbus, Ohio 43210 (United States); Center for Cosmology and Astro-Particle Physics, Ohio State University, Columbus, Ohio 43210 (United States); Horiuchi, Shunsaku [Department of Physics, School of Science, University of Tokyo, Tokyo 113-0033 (Japan); Beacom, John F. [Department of Physics, Ohio State University, Columbus, Ohio 43210 (United States); Center for Cosmology and Astro-Particle Physics, Ohio State University, Columbus, Ohio 43210 (United States); Department of Astronomy, Ohio State University, Columbus, Ohio 43210 (United States); Ando, Shin'ichiro [California Institute of Technology, Mail Code 130-33, Pasadena, California 91125 (United States)

2007-12-15T23:59:59.000Z

343

Towards closing the window on strongly interacting dark matter: Far-reaching constraints from Earth's heat flow  

SciTech Connect (OSTI)

We point out a new and largely model-independent constraint on the dark matter scattering cross section with nucleons, which applies when this quantity is larger than for typical weakly interacting dark matter candidates. When the dark matter capture rate in Earth is efficient, the rate of energy deposition by dark matter self-annihilation products would grossly exceed the measured heat flow of Earth. This improves the spin-independent cross section constraints by many orders of magnitude and closes the window between astrophysical constraints (at very large cross sections) and underground detector constraints (at small cross sections). In the applicable mass range, from {approx}1 to {approx}10{sup 10} GeV, the scattering cross section of dark matter with nucleons is then bounded from above by the latter constraints and hence must be truly weak, as usually assumed.

Mack, Gregory D. [Department of Physics, Ohio State University, Columbus, Ohio 43210 (United States); Center for Cosmology and Astro-Particle Physics, Ohio State University, Columbus, Ohio 43210 (United States); Beacom, John F. [Department of Physics, Ohio State University, Columbus, Ohio 43210 (United States); Center for Cosmology and Astro-Particle Physics, Ohio State University, Columbus, Ohio 43210 (United States); Department of Astronomy, Ohio State University, Columbus, Ohio 43210 (United States); Bertone, Gianfranco [Institut d'Astrophysique de Paris, UMR 7095-CNRS, Universite Pierre et Marie Curie, 98bis boulevard Arago, 75014 Paris (France)

2007-08-15T23:59:59.000Z

344

A Comprehensive Search for Dark Matter Annihilation in Dwarf Galaxies  

E-Print Network [OSTI]

We present a new formalism designed to discover dark matter annihilation occurring in the Milky Way's dwarf galaxies. The statistical framework extracts all available information in the data by simultaneously combining observations of all the dwarf galaxies and incorporating the impact of particle physics properties, the distribution of dark matter in the dwarfs, and the detector response. The method performs maximally powerful frequentist searches and produces confidence limits on particle physics parameters. Probability distributions of test statistics under various hypotheses are constructed exactly, without relying on large sample approximations. The derived limits have proper coverage by construction and claims of detection are not biased by imperfect background modeling. We implement this formalism using data from the Fermi Gamma-ray Space Telescope to search for an annihilation signal in the complete sample of Milky Way dwarfs whose dark matter distributions can be reliably determined. We find that the...

Geringer-Sameth, Alex; Walker, Matthew G

2014-01-01T23:59:59.000Z

345

Optical limiting materials  

DOE Patents [OSTI]

Optical limiting materials. Methanofullerenes, fulleroids and/or other fullerenes chemically altered for enhanced solubility, in liquid solution, and in solid blends with transparent glass (SiO.sub.2) gels or polymers, or semiconducting (conjugated) polymers, are shown to be useful as optical limiters (optical surge protectors). The nonlinear absorption is tunable such that the energy transmitted through such blends saturates at high input energy per pulse over a wide range of wavelengths from 400-1100 nm by selecting the host material for its absorption wavelength and ability to transfer the absorbed energy into the optical limiting composition dissolved therein. This phenomenon should be generalizable to other compositions than substituted fullerenes.

McBranch, Duncan W. (Santa Fe, NM); Mattes, Benjamin R. (Santa Fe, NM); Koskelo, Aaron C. (Los Alamos, NM); Heeger, Alan J. (Santa Barbara, CA); Robinson, Jeanne M. (Los Alamos, NM); Smilowitz, Laura B. (Los Alamos, NM); Klimov, Victor I. (Los Alamos, NM); Cha, Myoungsik (Goleta, CA); Sariciftci, N. Serdar (Santa Barbara, CA); Hummelen, Jan C. (Groningen, NL)

1998-01-01T23:59:59.000Z

346

MU(& Ge-+v,  

Office of Legacy Management (LM)

fil fil MU(& Ge-+v, . !d R&arch & Development b This document consists of 6 Contract Ho. pages and - . --------------_____---. figures No.--~--of.--~~-_-copies, Series,&,, This subcontract entered into this 20 day 0fSepte~ber , 1943, by and between the University of Cliicago, a corporation not for pecuniary profit organized under the ICVS of the Stnto of Illinois, of Chicago, Illinois (hereinafter called "the Contractor") and Yiolverine Tube Divisionof Caluzet 2 Eecla Consolidated Co;-,er co, . a cor?orntion organized under the laws cf the State of l~lch~;an - of Detroit, I:ichigan --- (hersinnftcr called "the Subcontractoi"). WIEHEAS, tho Contractor has heretofore onterod into a contract v;ith the United States of America (rcprcse;!tcd by its dtlly designated

347

Charm photoproduction at 20 GeV  

Science Journals Connector (OSTI)

Sixty-two charm events have been observed in an exposure of the SLAC Hybrid Facility toa backward sacttered laser beam. Based on 22 neutral and 21 charged decays we have measured the charmed-meson lifetimes to be ?D0=(6.8-1.8+2.3)10-13 sec, ?D=(7.4-2.0+2.3)10-13 sec and their ratio ?D?D0=1.1-0.3+0.6. The inclusive charm cross section at a photon energy of 20 GeV has been measured to be 56-23+24 nb. Evidence is presented for a non-DD component to charm production, consistent with (3520)% ?c+ production and some D* production. We have found no unambiguous F decays.

K. Abe et al. ((SLAC Hybrid Facility Photon Collaboration))

1984-07-01T23:59:59.000Z

348

3 GeV Injector Design Handbook  

SciTech Connect (OSTI)

This Design Handbook is intended to be the main reference book for the specifications of the 3 GeV SPEAR booster synchrotron project. It is intended to be a consistent description of the project including design criteria, key technical specifications as well as current design approaches. Since a project is not complete till it's complete changes and modifications of early conceptual designs must be expected during the duration of the construction. Therefore, this Design Handbook is issued as a loose leaf binder so that individual sections can be replaced as needed. Each page will be dated to ease identification with respect to latest revisions. At the end of the project this Design Handbook will have become the 'as built' reference book of the injector for operations and maintenance personnel.

Wiedemann, H.; /SLAC, SSRL

2009-12-16T23:59:59.000Z

349

Addendum to Heat and matter transport in binary liquid mixtures  

Science Journals Connector (OSTI)

We recently presented nonequilibrium molecular dynamics simulations of coupled heat and matter transport in a binary liquid mixture. While these simulations were carried out exactly as indicated, the relations given between the microscopic and macroscopic formalism were strictly wrong. Here we correct these errors and indicate how they limit the possibilities for comparison of our simulation results with experiment.

Denis J. Evans and David MacGowan

1987-07-15T23:59:59.000Z

350

Photoemission study of Si(111)-Ge(55) surfaces  

Science Journals Connector (OSTI)

Photoemission spectroscopy was used to study Si(111)-Ge(55) surfaces prepared by annealing Ge films deposited onto Si(111)-(77) substrates. The Si 2p core-level line shape was modified in going from (77) to (55) systems. By decomposing the spectra into bulk- and surface-shifted components the changes in line shape were identified as due to selective replacement of Si by Ge in different layers of the substrate, without any drastic change in the surface structure. The Ge 3d core-level line shape for the Si(111)-Ge(55) surface was also measured and compared with that for the Ge(111)-c(28) surface. These results are discussed in terms of models for the Si(111)-(77) structure. A surface state was observed on the Si(111)-Ge(55) surface, which gave rise to a metalliclike Fermi edge in the angle-integrated spectra; a similar surface state was observed on the Si(111)-(77) surface but not on the Ge(111)-c(28) surface.

T. Miller; T. C. Hsieh; T. -C. Chiang

1986-05-15T23:59:59.000Z

351

Vibrational dynamics in isotopically substituted vitreous GeO2  

Science Journals Connector (OSTI)

We report the polarized Raman spectra of vitreous Ge O216, Ge O218, Ge70O2, and Ge74O2. This yields the O16?O18 and Ge70?Ge74 isotopic shifts for nearly all vibrational modes of the pure glassy material. The shifts of the broad high-frequency (infrared-active) modes are as predicted by a nearest-neighbor central-force ideal continuousrandom-network model. The shift of the broad dominant Raman line indicates a small but significant dependence on the Ge mass, and this suggests an effect of disorder not included in the central-force theory. The narrow "defect" line at 530 cm-1 appears to be all oxygen motion, and is tentatively identified with a regular ring of bonds. The narrow line at 345 cm-1 is unique in that it exhibits very little oxygen shift; it seems to consist largely of Ge motion, for which we have no firm explanation.

F. L. Galeener; A. E. Geissberger; G. W. Ogar; Jr.; R. E. Loehman

1983-10-15T23:59:59.000Z

352

Tensor Detection Severely Constrains Axion Dark Matter  

E-Print Network [OSTI]

The recent detection of B-modes by BICEP2 has non-trivial implications for axion dark matter implied by combining the tensor interpretation with isocurvature constraints from Planck. In this paper the measurement is taken as fact, and its implications considered, though further experimental verification is required. In the simplest inflation models $r=0.2$ implies $H_I=1.1\\times 10^{14}\\text{ GeV}$. If the axion decay constant $f_a1$ accounts for theoretical uncertainty). If $f_a>H_I/2\\pi$ then vacuum fluctuations of the axion field place conflicting demands on axion DM: isocurvature constraints require a DM abundance which is too small to be reached when the back reaction of fluctuations is included. High $f_a$ QCD axions are thus ruled out. Constraints on axion-like particles, as a function of their mass and DM fraction, are also considered. For heavy axions with $m_a\\gtrsim 10^{-22}\\text{ eV}$ we find $\\Omega_a/\\Omega_d\\lesssim 10^{-3}$, with stronger constraints on heavier axions. Lighter axions, however, are allowed and (inflationary) model-independent constraints from the CMB temperature power spectrum and large scale structure are stronger than those implied by tensor modes.

David J. E. Marsh; Daniel Grin; Renee Hlozek; Pedro G. Ferreira

2014-03-17T23:59:59.000Z

353

The composition of the Fermi-LAT IGRB intensity: emission from extragalactic point sources and dark matter annihilations  

E-Print Network [OSTI]

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...

Di Mauro, Mattia

2015-01-01T23:59:59.000Z

354

Limited Commercial Maintenance (LCLM) Limited Lawn & Ornamental (LLO)  

E-Print Network [OSTI]

, Limited Commercial Landscape Maintenance, Ornamental & Turf, Private Ag, or General Standards CORE for Limited Commercial Landscape Maintenance (LCLM), you must attend all day to earn the 6 CEUs required. Limited Commercial Maintenance (LCLM) Limited Lawn & Ornamental (LLO) Training & Exams Date

Florida, University of

355

Secretary Chu Speaks at GE Solar Facility | Department of Energy  

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

Chu Speaks at GE Solar Facility Chu Speaks at GE Solar Facility Secretary Chu Speaks at GE Solar Facility November 18, 2011 - 1:19pm Addthis Secretary Steven Chu's remarks, as prepared for delivery, at the General Electric Solar Facility in Arvada, Colorado. Thank you, Fred [Seymour], for the introduction. GE is a leader in energy innovation. Thomas Edison, the father of GE, once said, "I'd put my money on the sun and solar energy. What a source of power!" I imagine he would be amazed by the solar technology that is tested here. It's great to be in Colorado, a state that is at the forefront of the clean energy economy and has more solar jobs per capita than any other state[i]. I'm here at a critical time for America's energy future. It's a time of challenge, but it's also a time of opportunity.

356

GE Nucleus for Residential Energy Use Education, Home Energy  

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

GE Nucleus for Residential Energy Use Education, Home Energy GE Nucleus for Residential Energy Use Education, Home Energy Management/Control, Residential Energy Integration Speaker(s): William Watts Date: August 4, 2011 - 12:00pm Location: 90-3122 Seminar Host/Point of Contact: Janie Page Home Energy Gateways offer a single point of access to the AMI Smart Meter into the home. The Nucleus is GE's home energy management gateway. The GE Nucleus securely communicates to a Smart Meter and delivers real-time whole home energy consumption data for display to the Consumer. The Consumer is able to visualize their energy usage habits on a Client that is connected via TLS encryption to the WiFi or Ethernet interface of the Nucleus. The Nucleus records history of the consumer's usage and cost data for tracking of energy consumption habits. GE has a suite of Smart Appliances that

357

GE Lighting Solutions: Noncompliance Determination (2013-SE-4901) |  

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

Noncompliance Determination (2013-SE-4901) Noncompliance Determination (2013-SE-4901) GE Lighting Solutions: Noncompliance Determination (2013-SE-4901) January 11, 2013 DOE issued a Notice of Noncompliance Determination to General Electric Lighting Solutions finding that various models of traffic signal modules do not comport with the energy conservation standards. DOE determined the products were noncompliant based on the company's own testing. GE Lighting Solutions must immediately notify each person (or company) to whom GE Lighting Solutions distributed the noncompliant products that the products do not meet Federal standards. In addition, GE Lighting Solutions must provide to DOE documents and records showing the number of units GE Lighting Solutions distributed and to whom. The manufacturer

358

TEM studies of Ge nanocrystal formation in PECVD grown  

Science Journals Connector (OSTI)

We investigate the effect of annealing on the Ge nanocrystal formation in multilayered germanosilicateoxide films grown on Si substrates by plasma enhanced chemical vapour deposition (PECVD). The multilayered samples were annealed at temperatures ranging from 750 to 900?C for 5min under nitrogen atmosphere. The onset of formation of Ge nanocrystals, at 750?C, can be observed via high resolution TEM micrographs. The diameters of Ge nanocrystals were observed to be between 5 and 14nm. As the annealing temperature is raised to 850?C, a second layer of Ge nanocrystals forms next to the original precipitation band, positioning itself closer to the substrate SiO2 interface. High resolution cross section TEM images, electron diffraction and electron energy-loss spectroscopy as well as energy-dispersive x-ray analysis (EDAX) data all indicate that Ge nanocrystals are present in each layer.

S A?an; A Dana; A Aydinli

2006-01-01T23:59:59.000Z

359

On atomic structure of Ge huts growing on the Ge/Si(001) wetting layer  

SciTech Connect (OSTI)

Structural models of growing Ge hut clusterspyramids and wedgesare proposed on the basis of data of recent STM investigations of nucleation and growth of Ge huts on the Si(001) surface in the process of molecular beam epitaxy. It is shown that extension of a hut base along <110> directions goes non-uniformly during the cluster growth regardless of its shape. Growing pyramids, starting from the second monolayer, pass through cyclic formation of slightly asymmetrical and symmetrical clusters, with symmetrical ones appearing after addition of every fourth monolayer. We suppose that pyramids of symmetrical configurations composed by 2, 6, 10, etc., monolayers over the wetting layer are more stable than asymmetrical ones. This might explain less stability of pyramids in comparison with wedges in dense arrays forming at low temperatures of Ge deposition. Possible nucleation processes of pyramids and wedges on wetting layer patches from identical embryos composed by 8 dimers through formation of 1 monolayer high 16-dimer nuclei different only in their symmetry is discussed. Schematics of these processes are presented. It is concluded from precise STM measurements that top layers of wetting layer patches are relaxed when huts nucleate on them.

Arapkina, Larisa V.; Yuryev, Vladimir A. [A. M. Prokhorov General Physics Institute of the Russian Academy of Sciences, 38 Vavilov Street, Moscow, 119991 (Russian Federation)] [A. M. Prokhorov General Physics Institute of the Russian Academy of Sciences, 38 Vavilov Street, Moscow, 119991 (Russian Federation)

2013-09-14T23:59:59.000Z

360

Nuclear Matter and Nuclear Dynamics  

E-Print Network [OSTI]

Highlights on the recent research activity, carried out by the Italian Community involved in the "Nuclear Matter and Nuclear Dynamics" field, will be presented.

M Colonna

2009-02-26T23:59:59.000Z

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


361

Low-temperature microwave magnetoresistance of lightly doped p-Ge and p-Ge1?x Six  

Science Journals Connector (OSTI)

The magnetoresistance of a lightly doped p-Ge1?x Six alloy is studied in the range of compositions x = 12 at %. The results are compared with the available data for lightly doped p-Ge. The studie...

A. I. Veinger; A. G. Zabrodskii; T. V. Tisnek

2005-10-01T23:59:59.000Z

362

Can we push the fundamental Planck scale above $10^{19}$ GeV?  

E-Print Network [OSTI]

The value of the quantum gravity scale is MPl = $10^{19}$ GeV. However, this is inherently a three-dimensional quantity. We know that we can bring this scale all the way down to TeV if we introduce extra dimensions with large volume. This will solve the hierarchy problem by destroying the desert between the electroweak and gravity scales, but will also introduce a host of new problems since some things (e.g. proton stability, neutrino masses etc) have their natural habitat in this desert. In contrast, we can also solve the hierarchy problem by reducing the number of dimensions at high energies. If the fundamental theory (which does not have to be gravity as we understand it today) is lower dimensional, then the fundamental energy scale might be much greater than 1019GeV. Then, some experimental and observational limits (e.g. on Lorentz invariance violation) which are coming close to or even exceeding the scale of 1019GeV can be evaded. In addition, scattering of particles at transplanckian energies will not p...

Stojkovic, Dejan

2014-01-01T23:59:59.000Z

363

Field Theory of Matter  

Science Journals Connector (OSTI)

A speculative field theory of matter is developed. Simple computational methods are used in a preliminary survey of its consequences. The theory exploits the known properties of leptons by means of a principle of symmetry between electrical and nucleonic charge. There are fundamental fields with spins 0, , 1. The spinless field is neutral. Spin and 1 fields can carry both electrical and nucleonic charge. The multiplicity of any nonzero charge is 3. Explicit dynamical mechanisms for the breakdown of unitary symmetry and for the muon-electron mass difference are given. A more general view of lepton properties is proposed. Mass relations for baryon and meson multiplets are derived, together with approximate couplings among the multiplets. The weakness of ? production in ?-N collisions and the suppression of the ???+? decay is explained.

Julian Schwinger

1964-08-10T23:59:59.000Z

364

Formation of Nanocrystalline Germanium via Oxidation of Si?.??Ge?.?? for Memory Device Applications  

E-Print Network [OSTI]

In this work, we studied the possibility of synthesizing nanocrystalline germanium (Ge) via dry and wet oxidation of both amorphous and polycrystalline Si?.??Ge?.?? films. In dry oxidation, Ge was rejected from the growing ...

Kan, Eric Win Hong

365

Origins of low resistivity and Ge donor level in Ge ion-implanted ZnO bulk single crystals  

SciTech Connect (OSTI)

The energy level of Ge in Ge-ion implanted ZnO single crystals is studied by Hall-effect and photoluminescence (PL) methods. The variations in resistivity from ?10{sup 3} ?cm for un-implanted samples to ?10{sup ?2} ?cm for as-implanted ones are observed. The resistivity is further decreased to ?10{sup ?3} ?cm by annealing. The origins of the low resistivity are attributed to both the zinc interstitial (Zn{sub i}) related defects and the electrical activated Ge donor. An activation energy of Ge donors estimated from the temperature dependence of carrier concentration is 102 meV. In PL studies, the new peak at 372 nm (3.33 eV) related to the Ge donor is observed in 1000 C annealed samples.

Kamioka, K.; Oga, T.; Izawa, Y.; Kuriyama, K. [College of Engineering and Research Center of Ion Beam Technology, Hosei University Koganei, Tokyo 184-8584 (Japan); Kushida, K. [Departments of Arts and Sciences, Osaka Kyoiku University Kashiwara, Osaka 582-8582 (Japan)

2013-12-04T23:59:59.000Z

366

Security Clearances; Limitations  

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

SEC. 1072. SECURITY CLEARANCES; LIMITATIONS. SEC. 1072. SECURITY CLEARANCES; LIMITATIONS. (a) In General.-Title III of the Intelligence Reform and Terrorism Prevention Act of 2004 (50 U.S.C. 435b) is amended by adding at the end the following new section: "SEC. 3002. SECURITY CLEARANCES; LIMITATIONS. "(a) Definitions.-In this section: "(1) Controlled substance.-The term `controlled substance' has the meaning given that term in section 102 of the Controlled Substances Act (21 U.S.C. 802). "(2) Covered person.-The term `covered person' means- "(A) an officer or employee of a Federal agency; "(B) a member of the Army, Navy, Air Force, or Marine Corps who is on active duty or is in an active status; and "(C) an officer or employee of a contractor of a Federal agency.

367

dark matter dark energy inflation  

E-Print Network [OSTI]

theory dark matter dark energy inflation The National Science Foundation The Kavli Foundation NSF Site Review November 28-29, 2005 #12;dark matter dark energy inflation NSF Site Visit ­ November 28 - 29, 2005The National Science Foundation The Kavli Foundation The Theoretical Web UHE cosmic rays B

Hu, Wayne

368

Organic matter in ancient meteorites  

Science Journals Connector (OSTI)

......asteroids. 3: Organic matter in...lead to the production of hydroxy...useful in cell membranes...a part in cell membranes...meteorite organic matter because...form the solar system bequeathed...the early solar system and organic-inorganic......

Mark A Sephton

2004-04-01T23:59:59.000Z

369

Energy Matters in Washington State  

E-Print Network [OSTI]

Energy Matters in Washington State Energy Matters in Washington State www.energy.wsu.edu/library/ November 2009 #12;905 Plum Street SE, Building 3 P.O. Box 43169 Olympia, Washington 98504-3169 Energy University Extension Energy Program. 905 Plum Street SE, Building 3, P.O. Box 43169, Olympia, Washington

Collins, Gary S.

370

A Reconsideration of Matter Waves  

E-Print Network [OSTI]

Matter waves were discovered in the early 20th century from their wavelength, predicted by DeBroglie, Planck's constant divided by the particle's momentum, that is, lmw = h/mv. But, the failure to obtain a reasonable theory for the matter wave frequency resulted somewhat in loss of further interest. It was expected that the frequency of the matter wave should correspond to the particle kinetic energy, that is, fmw = 1/2mv^2/h but the resulting velocity of the matter of the particle, v = fmw x lmw, is that the matter wave moves at one half the speed of the particle, obviously absurd as the particle and its wave must move together. If relativistic mass is used (as it should in any case) the problem remains, the same mass appearing in numerator and denominator and canceling. It is no help to hypothesize that the total energy, not just the kinetic energy, yields the matter wave. That attributes a matter wave to a particle at rest. It also gives the resulting velocity as c^2/v, the wave racing ahead of its particle. A reinterpretation of Einstein's derivation of relativistic kinetic energy (which produced his famous E = mc^2) leads to a valid matter wave frequency and a new understanding of particle kinetics and of the atom's stable orbits.

Roger Ellman

2005-05-16T23:59:59.000Z

371

Energy Gap in Nuclear Matter  

Science Journals Connector (OSTI)

......research-article Articles Energy Gap in Nuclear Matter Takeshi Ishihara a...Research, Kokubunji, Tokyo An energy gap in nuclear matter is studied. The nucleon-nucleon...1966) pp. 1026-1042 Nuclear Force and Energy Gap in Finite Nuclei Hiroharu......

Takeshi Ishihara; Ryozo Tamagaki; Hajime Tanaka; Masaru Yasuno

1963-11-01T23:59:59.000Z

372

Low temperature epitaxial growth of Ge on cube- textured Ni  

SciTech Connect (OSTI)

Quasi- single crystal Ge films were grown on [001]<010> textured Ni substrate at a temperature of 350 oC using an insulating buffer layer of CaF2. A direct deposition of Ge on Ni at 350 oC was shown to alloy with Ni. From x- ray pole figure analysis, it was shown that Ge grew epitaxially with the same orientation as CaF2 and the dispersions in the out- of- plane and in- plane directions were found to be 1.7 0.1o and 6 1o, respectively. In the out- of- plane direction, Ge[111]||CaF2[111]||Ni[001]. In addition, the Ge consisted of four equivalent in- plane oriented domains such that two mutually orthogonal directions: Ge 211 and Ge 011 are parallel to mutually orthogonal directions: Ni 110 and Ni 110 , respectively of the Ni(001) surface. This was shown to be originated from the four equivalent in- plane oriented domains of CaF2 created to minimize the mismatch strain between CaF2 and Ni in those directions.

GIARE, C [Rensselaer Polytechnic Institute (RPI); Palazzo, J [Rensselaer Polytechnic Institute (RPI); Goyal, Amit [ORNL; WANG, G [Rensselaer Polytechnic Institute (RPI); LU, T [Rensselaer Polytechnic Institute (RPI)

2012-01-01T23:59:59.000Z

373

Screening Effects in Superfluid Nuclear and Neutron Matter within Brueckner Theory  

E-Print Network [OSTI]

Effects of medium polarization are studied for $^1S_0$ pairing in neutron and nuclear matter. The screening potential is calculated in the RPA limit, suitably renormalized to cure the low density mechanical instability of nuclear matter. The selfenergy corrections are consistently included resulting in a strong depletion of the Fermi surface. All medium effects are calculated based on the Brueckner theory. The $^1S_0$ gap is determined from the generalized gap equation. The selfenergy corrections always lead to a quenching of the gap, which is enhanced by the screening effect of the pairing potential in neutron matter, whereas it is almost completely compensated by the antiscreening effect in nuclear matter.

L. G. Cao; U. Lombardo; P. Schuck

2006-08-01T23:59:59.000Z

374

XENON dark matter searches: Results and the future  

SciTech Connect (OSTI)

XENON100 is a dark matter search experiment looking for elastic WIMP scattering using a 62 kg liquid target. WIMP search data from XENON100 published in 2012 has set the world's strongest limits on WIMP-nucleus spinindependent, elastic scattering. It has also set the strongest limits on WIMP-nucleus spin-dependent scattering considering neutron scattering only, and competitive limits considering proton scattering only. The successor experiment to XENON100, XENON1T, is currently under construction, with commissioning scheduled to begin in 2014. XENON1T's design goal is a 100 fold increase in sensitivity for elastic WIMP searches over XENON100.

Brown, Andrew [Physics Department, Purdue University - 525 Northwestern Ave., West Lafayette, IN 47907 (United States); Collaboration: XENON Collaboration

2014-06-24T23:59:59.000Z

375

The possibility of improving the structural perfection of the new heterojunctions GaAs-(Ge2)1? x (ZnSe)x, Ge-(Ge2)1?x (ZnSe)x, GaP-(Ge2)1?x (ZnSe)x, and Si-(Ge2)1?x (ZnSe)x  

Science Journals Connector (OSTI)

Based on morphological investigations, as well as on a study of the scanning patterns and diffraction spectra of the heterostructures GaAs-(Ge2)1?x (ZnSe)x, Ge-(Ge2)1?x (ZnSe)x, Ga...

A. S. Saidov; . A. Koshchanov; A. Sh. Razzakov

1998-01-01T23:59:59.000Z

376

The Cryogenic Dark Matter Search: First 5-Tower Data and Improved Understanding of Ionization Collection  

SciTech Connect (OSTI)

The Cryogenic Dark Matter Search (CDMS) is searching for Weakly Interacting Massive Particles (WIMPs) with cryogenic particle detectors. These detectors have the ability to discriminate between nuclear recoil candidate and electron recoil background events by collecting both phonon and ionization energy from recoils in the detector crystals. The CDMS-II experiment has completed analysis of the first data runs with 30 semiconductor detectors at the Soudan Underground Laboratory, resulting in a world leading WIMP-nucleon spin-independent cross section limit for WIMP masses above 44 GeV/c{sup 2}. As CDMS aims to achieve greater WIMP sensitivity, it is necessary to increase the detector mass and discrimination between signal and background events. Incomplete ionization collection results in the largest background in the CDMS detectors as this causes electron recoil background interactions to appear as false candidate events. Two primary causes of incomplete ionization collection are surface and bulk trapping. Recent work has been focused on reducing surface trapping through the modification of fabrication methods for future detectors. Analyzing data taken with test devices has shown that hydrogen passivation of the amorphous silicon blocking layer worsens surface trapping. Additional data has shown that the iron-ion implantation used to lower the critical temperature of the tungsten transition-edge sensors causes a degradation of the ionization collection. Using selective implantation on future detectors may improve ionization collection for events near the phonon side detector surface. Bulk trapping is minimized by neutralizing ionized lattice impurities. Detector investigations at testing facilities and in situ at the experimental site have provided methods to optimize the neutralization process and monitor running conditions to maintain full ionization collection. This work details my contribution to the 5-tower data taking, monitoring, and analysis effort as well as the SuperCDMS detector development with the focus on monitoring and improving ionization collection in the detectors.

Bailey, Catherine N.; /Case Western Reserve U.

2010-01-01T23:59:59.000Z

377

CDF Note 9674 Combined Upper Limit on Standard Model Higgs Boson Production for Winter 2009  

E-Print Network [OSTI]

CDF Note 9674 Combined Upper Limit on Standard Model Higgs Boson Production for Winter 2009 The CDF of searches for the Standard Model Higgs boson at CDF. The six major analyses combined are the WH bV/c2 in steps of 5 GeV/c2 , assuming Standard Model decay branching fractions of the Higgs boson

Fermilab

378

GeV Emission from Collisional Magnetized Gamma Ray Bursts  

E-Print Network [OSTI]

Magnetic fields may play a dominant role in gamma-ray bursts, and recent observations by the Fermi satellite indicate that GeV radiation, when detected, arrives delayed by seconds from the onset of the MeV component. Motivated by this, we discuss a magnetically dominated jet model where both magnetic dissipation and nuclear collisions are important. We show that, for parameters typical of the observed bursts, such a model involving a realistic jet structure can reproduce the general features of the MeV and a separate GeV radiation component, including the time delay between the two. The model also predicts a multi-GeV neutrino component.

P. Mszros; M. J. Rees

2011-04-26T23:59:59.000Z

379

Dark Matter distribution in the Milky Way: microlensing and dynamical constraints  

SciTech Connect (OSTI)

We show that current microlensing and dynamical observations of the Galaxy permit to set interesting constraints on the Dark Matter local density and profile slope towards the galactic centre. Assuming state-of-the-art models for the distribution of baryons in the Galaxy, we find that the most commonly discussed Dark Matter profiles (viz. Navarro-Frenk-White and Einasto) are consistent with microlensing and dynamical observations, while extreme adiabatically compressed profiles are robustly ruled out. When a baryonic model that also includes a description of the gas is adopted, our analysis provides a determination of the local Dark Matter density, ?{sub 0} = 0.20?0.56 GeV/cm{sup 3} at 1?, that is found to be compatible with estimates in the literature based on different techniques.

Iocco, Fabio; Bertone, Gianfranco [Institut d'Astrophysique de Paris, UMR 7095-CNRS, Univ. Pierre and Marie Curie, 98bis Bd Arago 75014 Paris (France); Pato, Miguel; Jetzer, Philippe, E-mail: iocco@iap.fr, E-mail: migpato@physik.uzh.ch, E-mail: gf.bertone@gmail.com, E-mail: jetzer@physik.uzh.ch [Institute for Theoretical Physics, University of Zrich, Winterthurerstrasse 190, 8057 Zrich (Switzerland)

2011-11-01T23:59:59.000Z

380

Constraints on the dark matter particle mass from the number of Milky Way satellites  

SciTech Connect (OSTI)

We have conducted N-body simulations of the growth of Milky Way-sized halos in cold and warm dark matter cosmologies. The number of dark matter satellites in our simulated Milky Ways decreases with decreasing mass of the dark matter particle. Assuming that the number of dark matter satellites exceeds or equals the number of observed satellites of the Milky Way, we derive lower limits on the dark matter particle mass. We find with 95% confidence m{sub s}>13.3 keV for a sterile neutrino produced by the Dodelson and Widrow mechanism, m{sub s}>8.9 keV for the Shi and Fuller mechanism, m{sub s}>3.0 keV for the Higgs decay mechanism, and m{sub WDM}>2.3 keV for a thermal dark matter particle. The recent discovery of many new dark matter dominated satellites of the Milky Way in the Sloan Digital Sky Survey allows us to set lower limits comparable to constraints from the complementary methods of Lyman-{alpha} forest modeling and x-ray observations of the unresolved cosmic x-ray background and of dark matter halos from dwarf galaxy to cluster scales. Future surveys like LSST, DES, PanSTARRS, and SkyMapper have the potential to discover many more satellites and further improve constraints on the dark matter particle mass.

Polisensky, Emil [Naval Research Laboratory, Washington, D.C. 20375 (United States); Department of Astronomy, University of Maryland, College Park, Maryland 20745 (United States); Ricotti, Massimo [Department of Astronomy, University of Maryland, College Park, Maryland 20745 (United States)

2011-02-15T23:59:59.000Z

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


381

Long-Range Pseudorapidity Correlations at High pT in sqrt(S_NN) = 200 GeV Au+Au Collisions with STAR  

E-Print Network [OSTI]

-range correlation in pseudorapidity (the ?Ridge?) was studied (with statistical significance) out to pT^trig. GeV /c and was assumed to have an integrated yield independent of pT^trig. Further studies out to higher pT were limited by the minimum biased...

Codrington, Martin John Michael

2012-10-19T23:59:59.000Z

382

Intermixing between HfO{sub 2} and GeO{sub 2} films deposited on Ge(001) and Si(001): Role of the substrate  

SciTech Connect (OSTI)

Thermally driven atomic transport in HfO{sub 2}/GeO{sub 2}/substrate structures on Ge(001) and Si(001) was investigated in N{sub 2} ambient as function of annealing temperature and time. As-deposited stacks showed no detectable intermixing and no instabilities were observed on Si. On Ge, loss of O and Ge was detected in all annealed samples, presumably due to evolution of GeO from the GeO{sub 2}/Ge interface. In addition, hafnium germanate is formed at 600 deg. C. Our data indicate that at 500 deg. C and above HfO{sub 2}/GeO{sub 2} stacks are stable only if isolated from the Ge substrate.

Soares, G. V.; Krug, C. [Instituto de Fisica, UFRGS, Porto Alegre, Rio Grande do Sul 91509-900 (Brazil); Miotti, L.; Bastos, K. P.; Lucovsky, G. [Department of Physics, North Carolina State University, Raleigh, North Carolina 27695 (United States); Baumvol, I. J. R. [Instituto de Fisica, UFRGS, Porto Alegre, Rio Grande do Sul 91509-900 (Brazil); Universidade de Caxias do Sul, Caxias do Sul, Rio Grande do Sul 95070-560 (Brazil); Radtke, C. [Instituto de Quimica, UFRGS, Porto Alegre, Rio Grande do Sul 91509-900 (Brazil)

2011-03-28T23:59:59.000Z

383

Energy Lossand Flow of Heavy Quarks in Au+Au Collisions at root-s=200GeV  

SciTech Connect (OSTI)

The PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC) has measured electrons with 0.3 < p{sub rmT} < 9 GeV/c at midrapidity (|y| < 0.35) from heavy flavor (charm and bottom) decays in Au+Au collisions at {radical}s{sub NN} = 200 GeV. The nuclear modification factor R{sub AA} relative to p+p collisions shows a strong suppression in central Au+Au collisions, indicating substantial energy loss of heavy quarks in the medium produced at RHIC energies. A large azimuthal anisotropy, v{sub 2}, with respect to the reaction plane is observed for 0.5 < p{sub rmT} < 5 GeV/c indicating non-zero heavy flavor elliptic flow. A simultaneous description of R{sub AA}(p{sub rmT}) and v{sub 2}(p{sub rmT}) constrains the existing models of heavy-quark rescattering in strongly interacting matter and provides information on the transport properties of the produced medium. In particular, a viscosity to entropy density ratio close to the conjectured quantum lower bound, i.e. near a perfect fluid, is suggested.

Soltz, R; Klay, J; Enokizono, A; Newby, J; Heffner, M; Hartouni, E

2007-02-26T23:59:59.000Z

384

Identified high-pT spectra in Cu+Cu collisions at sqrt sNN=200 GeV  

SciTech Connect (OSTI)

We report new results on identified (anti)proton and charged pion spectra at large transverse momenta (3 < p{sub T} < 10 GeV/c) from Cu+Cu collisions at {radical}s{sub NN} = 200 GeV using the STAR detector at the Relativistic Heavy Ion Collider (RHIC). This study explores the system size dependence of two novel features observed at RHIC with heavy ions: the hadron suppression at high-p{sub T} and the anomalous baryon to meson enhancement at intermediate transverse momenta. Both phenomena could be attributed to the creation of a new form of QCD matter. The results presented here bridge the system size gap between the available pp and Au+Au data, and allow the detailed exploration for the on-set of the novel features. Comparative analysis of all available 200 GeV data indicates that the system size is a major factor determining both the magnitude of the hadron spectra suppression at large transverse momenta and the relative baryon to meson enhancement.

STAR Collaboration; Abelev, Betty

2010-07-05T23:59:59.000Z

385

Atomic layer-by-layer oxidation of Ge (100) and (111) surfaces by plasma post oxidation of Al{sub 2}O{sub 3}/Ge structures  

SciTech Connect (OSTI)

The ultrathin GeO{sub x}/Ge interfaces formed on Ge (100) and (111) surfaces by applying plasma post oxidation to thin Al{sub 2}O{sub 3}/Ge structures are characterized in detail using X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy. It is found that the XPS signals assigned to Ge 1+ and the 2+ states in the GeO{sub x} layers by post plasma oxidation have oscillating behaviors on Ge (100) surfaces in a period of {approx}0.3 nm with an increase in the GeO{sub x} thickness. Additionally, the oscillations of the signals assigned to Ge 1+ and 2+ states show opposite phase to each other. The similar oscillation behaviors are also confirmed on Ge (111) surfaces for Ge 1+ and 3+ states in a period of {approx}0.5 nm. These phenomena can be strongly regarded as an evidence of the atomic layer-by-layer oxidation of GeO{sub x}/Ge interfaces on Ge (100) and (111) surfaces.

Zhang, Rui [School of Engineering, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-8656 (Japan) [School of Engineering, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-8656 (Japan); School of Electronic Science and Engineering, Nanjing University, 22 Hankou Road, Nanjing 210093 (China); Huang, Po-Chin; Lin, Ju-Chin; Takenaka, Mitsuru; Takagi, Shinichi [School of Engineering, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-8656 (Japan)] [School of Engineering, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-8656 (Japan)

2013-02-25T23:59:59.000Z

386

Quantum dynamics in the thermodynamic limit  

SciTech Connect (OSTI)

The description of spontaneous symmetry breaking that underlies the connection between classically ordered objects in the thermodynamic limit and their individual quantum-mechanical building blocks is one of the cornerstones of modern condensed-matter theory and has found applications in many different areas of physics. The theory of spontaneous symmetry breaking, however, is inherently an equilibrium theory, which does not address the dynamics of quantum systems in the thermodynamic limit. Here, we will use the example of a particular antiferromagnetic model system to show that the presence of a so-called thin spectrum of collective excitations with vanishing energy - one of the well-known characteristic properties shared by all symmetry-breaking objects - can allow these objects to also spontaneously break time-translation symmetry in the thermodynamic limit. As a result, that limit is found to be able, not only to reduce quantum-mechanical equilibrium averages to their classical counterparts, but also to turn individual-state quantum dynamics into classical physics. In the process, we find that the dynamical description of spontaneous symmetry breaking can also be used to shed some light on the possible origins of Born's rule. We conclude by describing an experiment on a condensate of exciton polaritons which could potentially be used to experimentally test the proposed mechanism.

Wezel, Jasper van [Theory of Condensed Matter, Cavendish Laboratory, University of Cambridge, Madingley Road, Cambridge CB3 0HE (United Kingdom)

2008-08-01T23:59:59.000Z

387

CCDM model from quantum particle creation: constraints on dark matter mass  

E-Print Network [OSTI]

In this work the results from the quantum process of matter creation have been used in order to constrain the mass of the dark matter particles in an accelerated Cold Dark Matter model (Creation Cold Dark Matter, CCDM). In order to take into account a back reaction effect due to the particle creation phenomenon, it has been assumed a small deviation $\\varepsilon$ for the scale factor in the matter dominated era of the form $t^{\\frac{2}{3}+\\varepsilon}$. Based on recent $H(z)$ data, the best fit values for the mass of dark matter created particles and the $\\varepsilon$ parameter have been found as $m=1.6\\times10^3$ GeV, restricted to a 68.3\\% c.l. interval of ($1.5GeV and $\\varepsilon = -0.250^{+0.15}_{-0.096}$ at 68.3\\% c.l. For these best fit values the model correctly recovers a transition from decelerated to accelerated expansion and admits a positive creation rate near the present era. Contrary to recent works in CCDM models where the creation rate was phenomenologically derived, here we have used a quantum mechanical result for the creation rate of real massive scalar particles, given a self consistent justification for the physical process. This method also indicates a possible solution to the so called "dark degeneracy", where one can not distinguish if it is the quantum vacuum contribution or quantum particle creation which accelerates the Universe expansion.

J. F. Jesus; S. H. Pereira

2014-06-16T23:59:59.000Z

388

GE Appliances: Proposed Penalty (2010-CE-2113) | Department of Energy  

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

GE Appliances: Proposed Penalty (2010-CE-2113) GE Appliances: Proposed Penalty (2010-CE-2113) GE Appliances: Proposed Penalty (2010-CE-2113) September 8, 2010 DOE alleged in a Notice of Proposed Civil Penalty that General Electric Appliances failed to certify a variety of dehumidifiers as compliant with the applicable energy conservation standards. DOE regulations require a manufacturer (which includes importers) to submit reports certifying that its products have been tested and meet the applicable energy conservation standards. This civil penalty notice advises the company of the potential penalties and DOE's administrative process, including the company's right to a hearing. GE Appliances: Proposed Penalty (2010-CE-2113) More Documents & Publications De'Longhi USA: Proposed Penalty (2010-CE-2114)

389

GE Lighting Solutions: Proposed Penalty (2013-SE-4901) | Department of  

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

GE Lighting Solutions: Proposed Penalty (2013-SE-4901) GE Lighting Solutions: Proposed Penalty (2013-SE-4901) GE Lighting Solutions: Proposed Penalty (2013-SE-4901) March 5, 2013 DOE alleged in a Notice of Proposed Civil Penalty that General Electric Lighting Solutions manufactured and distributed noncompliant traffic signal modules in the U.S. Federal law subjects manufacturers and private labelers to civil penalties if those parties distribute in the U.S. products that do not meet applicable energy conservation standards. This civil penalty notice advises the company of the potential penalties and DOE's administrative process, including the company's right to a hearing. GE Lighting Solutions: Proposed Penalty (2013-SE-4901) More Documents & Publications Act One: NPCP (2013-CE-49001) Excellence Opto: Proposed Penalty (2013-CE-49002)

390

Crystal Lake - GE Energy Wind Farm | Open Energy Information  

Open Energy Info (EERE)

GE Energy Wind Farm GE Energy Wind Farm Jump to: navigation, search Name Crystal Lake - GE Energy Wind Farm Facility Crystal Lake - GE Energy Sector Wind energy Facility Type Commercial Scale Wind Facility Status In Service Owner NextEra Energy Resources Developer NextEra Energy Resources Location IA Coordinates 43.194201°, -93.860521° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":43.194201,"lon":-93.860521,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

391

Northern Colorado Wind Energy Center (GE) | Open Energy Information  

Open Energy Info (EERE)

Center (GE) Center (GE) Jump to: navigation, search Name Northern Colorado Wind Energy Center (GE) Facility Northern Colorado Wind Energy Center (GE) Sector Wind energy Facility Type Commercial Scale Wind Facility Status In Service Owner NextEra Energy Developer NextEra Energy Energy Purchaser Xcel Energy Location Logan County CO Coordinates 40.974539°, -103.025336° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":40.974539,"lon":-103.025336,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

392

ORNL Partners with GE on New Hybrid | ornl.gov  

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

ORNL Partners with GE on New Hybrid ORNL Partners with GE on New Hybrid September 02, 2011 Water Heater About 400 jobs will soon be created at a Louisville General Electric plant at which a new electric water heater will be built. The technology was developed through a collaboration between ORNL and GE. The appliance will meet the new Energy Star water heater program criteria, which require future heaters to be twice as efficient as an electric storage water heater, positioning GE to be the first company to meet the energy-saving standard. According to DOE, using devices that meet these criteria should save American households approximately $780 million. ORNL's Patrick Hughes said the water heater will benefit consumers with its energy efficiency as well as its cost savings. "It will give you as much hot water and have the same recovery times so you

393

Intern Shares Insight Into Researchers' Minds |GE Global Research  

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

rest of the year, I am a Ph.D. candidate at Virginia Tech, where my research is in aerodynamics and instrumentation development. At school, my work is supported by GE Power and...

394

A Deep Dive into the Subsea Environment | GE Global Research  

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

every step must be carried out in a safe manner to assure the risk of any serious accident is kept low, with very tight and conservative control. Filling the need GE...

395

Laser Guiding for GeV Laser-Plasma Accelerators  

E-Print Network [OSTI]

Overview of plasma-based accelerator concepts. IEEE Trans.using laser wake?eld accelerators. Meas. Sci. Technol. 12,for GeV laser-plasma accelerators. In Advanced Accelerator

Leemans, Wim; Esarey, Eric; Geddes, Cameron; Schroeder, C.B.; Toth, Csaba

2005-01-01T23:59:59.000Z

396

Making Silicon Carbide Devices in the Cleanroom | GE Global Research  

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

Silicon Carbide Devices in the Cleanroom Making Silicon Carbide Devices in the Cleanroom Ron Olson 2012.08.23 As the Wide Bandgap Process and Fab manager for the GE Global Research...

397

Ge-on-Si laser operating at room temperature  

E-Print Network [OSTI]

Monolithic lasers on Si are ideal for high-volume and large-scale electronicphotonic integration. Ge is an interesting candidate owing to its pseudodirect gap properties and compatibility with Si complementary metal oxide ...

Liu, Jifeng

398

Helping Astronauts Back on Earth | GE Global Research  

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

Helping Astronauts Back on Earth Helping Astronauts Back on Earth Vikas Revanna Shivaprabhu 2014.09.11 I received an email in early May from GE Global Research regarding a summer...

399

Take a Closer Look at the Brain | GE Global Research  

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

Take a Closer Look at the Brain Take a Closer Look at the Brain Worldwide, more than 450 million people are living with compromised brain health. GE Global Research scientists,...

400

Be a part of something bigger than yourself GE Healthcare  

E-Print Network [OSTI]

, reliability, cost and manufacturability. Work is done using 3D CAD systems. Leading engineering tasks external covers, packaging, mechanisms, cables & harnesses, labelling, and packaging. Knowledge Healthcare, a $17 billion division of General Electric Company. GE Healthcare's broad range of products

Rimon, Elon

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


401

Cloud-Based Air Traffic Management Announcement | GE Global Research  

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

Works to Bring Air Traffic Management Into "The Cloud" GE Works to Bring Air Traffic Management Into "The Cloud" A global leader in avionics and software development, the General...

402

Sandia National Laboratories: Northrop-Grumman, GE Partnerships...  

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

Experience Northrop-Grumman, GE Partnerships Tap a Wide Range of Sandia Labs Experience Solar Energy Research Institute for India and the United States Kick-Off American Chemical...

403

Steve Duclos, Chief Scientist, GE Global Research, Research Priorities...  

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

essionC3Duclos-GE.pdf More Documents & Publications Trans-Atlantic Workshop on Rare Earth Elements and Other Critical Materials for a Clean Energy Future Iowa lab gets critical...

404

Wind Turbine Transportation in Toyland | GE Global Research  

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

Edison's Desk > Wind Turbine Transportation in Toyland Wind Turbine Transportation in Toyland Charles (Burt) Theurer 2011.05.27 GE doesn't just make wind turbines. We also deliver...

405

LNG Technology Is in the News | GE Global Research  

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

LNG Technology Is in the News LNG Technology Is in the News Laura Hudy 2013.02.07 My name is Laura Hudy, and I lead the Thermal Energy Systems team at GE Global Research. One of...

406

Ge quantum dots structural peculiarities depending on the preparation conditions  

Science Journals Connector (OSTI)

EXAFS and XANES spectroscopy methods have been applied in a study of the influence of the preparation conditions on the spatial and electronic structure of Ge/Si heterostructures.

Erenburg, S.

2003-08-28T23:59:59.000Z

407

Notrees 1B (GE Energy) Wind Farm | Open Energy Information  

Open Energy Info (EERE)

B (GE Energy) Wind Farm B (GE Energy) Wind Farm Jump to: navigation, search Name Notrees 1B (GE Energy) Wind Farm Facility Notrees 1B (GE Energy) Sector Wind energy Facility Type Commercial Scale Wind Facility Status In Service Owner Duke Energy Carolinas LLC Developer Duke Energy Carolinas LLC Location TX Coordinates 31.9685988°, -99.9018131° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":31.9685988,"lon":-99.9018131,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

408

Enhanced Oil Recovery to Fuel Future Oil Demands | GE Global...  

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

to Fuel Future Oil Demands Enhanced Oil Recovery to Fuel Future Oil Demands Trevor Kirsten 2013.10.02 I'm Trevor Kirsten and I lead a team of GE researchers that investigate a...

409

Heat flux limiting sleeves  

DOE Patents [OSTI]

A heat limiting tubular sleeve extending over only a portion of a tube having a generally uniform outside diameter, the sleeve being open on both ends, having one end thereof larger in diameter than the other end thereof and having a wall thickness which decreases in the same direction as the diameter of the sleeve decreases so that the heat transfer through the sleeve and tube is less adjacent the large diameter end of the sleeve than adjacent the other end thereof.

Harris, William G. (Tampa, FL)

1985-01-01T23:59:59.000Z

410

Probing the Structure of {sup 74}Ge Nucleus with Coupled-channels Analysis of {sup 74}Ge+{sup 74}Ge Fusion Reaction  

SciTech Connect (OSTI)

We study the fusion reaction of the {sup 74}Ge+{sup 74}Ge system in term of the full order coupled-channels formalism. We especially calculated the fusion cross section as well as the fusion barrier distribution of this reaction using transition matrix suggested by recent Coulomb excitation experiment. We compare the results with the one obtained by coupling matrix based on pure vibrational and rotational models. The present coupled-channels calculations for the barrier distributions obtained using experiment coupling matrix is in good agreement with the one obtained with vibrational model, in contrast to the rotational model. This is indicates that {sup 74}Ge nucleus favor a spherical shape than a deformed shape in its ground state. Our results will resolve the debates concerning the structure of this nucleus.

Zamrun F, Muhammad [Deparment of Physics University of Malaya, Kuala Lumpur, 50603 (Malaysia); Jurusan Fisika FMIPA, Universitas Haluoleo, Kendari, Sulawesi Tenggara, 93232 (Indonesia); Kasim, Hasan Abu [Deparment of Physics University of Malaya, Kuala Lumpur, 50603 (Malaysia)

2010-12-23T23:59:59.000Z

411

MiniCLEAN Dark Matter Experiment  

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

MiniCLEAN MiniCLEAN Dark Matter Experiment Investigating the field of high energy physics through experiments that strengthen our fundamental understanding of matter, energy,...

412

Modeling of 10 GeV-1 TeV laser-plasma accelerators using Lorentz booster simulations  

SciTech Connect (OSTI)

Modeling of laser-plasma wakefield accelerators in an optimal frame of reference [J.-L. Vay, Phys. Rev. Lett. 98 130405 (2007)] allows direct and e#14;fficient full-scale modeling of deeply depleted and beam loaded laser-plasma stages of 10 GeV-1 TeV (parameters not computationally accessible otherwise). This verifies the scaling of plasma accelerators to very high energies and accurately models the laser evolution and the accelerated electron beam transverse dynamics and energy spread. Over 4, 5 and 6 orders of magnitude speedup is achieved for the modeling of 10 GeV, 100 GeV and 1 TeV class stages, respectively. Agreement at the percentage level is demonstrated between simulations using different frames of reference for a 0.1 GeV class stage. Obtaining these speedups and levels of accuracy was permitted by solutions for handling data input (in particular particle and laser beams injection) and output in a relativistically boosted frame of reference, as well as mitigation of a high-frequency instability that otherwise limits effectiveness.

Vay, J.-L.; Geddes, C.G.R.; Esarey, E.; Esarey, E.; Leemans, W.P.; Cormier-Michel, E.; Grote, D.P.

2011-12-01T23:59:59.000Z

413

Light Dark Matter in the light of CRESST-II  

SciTech Connect (OSTI)

Recently the CRESST collaboration has published the long anticipated results of their direct Dark Matter (DM) detection experiment with a CaWO4 target. The number of observed events exceeds known backgrounds at more than 4? significance, and this excess could potentially be due to DM scattering. We confront this interpretation with null results from other direct detection experiments for a number of theoretical models, and find that consistency is achieved in non-minimal models such as inelastic DM and isospin-violating DM. In both cases mild tension with constraints remain. The CRESST data can, however, not be reconciled with the null results and with the positive signals from DAMA and CoGeNT simultaneously in any of the models we study.

Kopp, Joachim; Schwetz, Thomas; Zupan, Jure

2012-03-01T23:59:59.000Z

414

Light Dark Matter in the light of CRESST-II  

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

Recently the CRESST collaboration has published the long anticipated results of their direct Dark Matter (DM) detection experiment with a CaWO4 target. The number of observed events exceeds known backgrounds at more than 4? significance, and this excess could potentially be due to DM scattering. We confront this interpretation with null results from other direct detection experiments for a number of theoretical models, and find that consistency is achieved in non-minimal models such as inelastic DM and isospin-violating DM. In both cases mild tension with constraints remain. The CRESST data can, however, not be reconciled with the null results and with the positive signals from DAMA and CoGeNT simultaneously in any of the models we study.

Kopp, Joachim; Schwetz, Thomas; Zupan, Jure

2012-03-01T23:59:59.000Z

415

Hot and Dense QCD Matter  

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

QCD Matter QCD Matter A Community White Paper on the Future of Relativistic Heavy-Ion Physics in the US Unraveling the Mysteries of the Strongly Interacting Quark-Gluon-Plasma Executive Summary This document presents the response of the US relativistic heavy-ion community to the request for comments by the NSAC Subcommittee, chaired by Robert Tribble, that is tasked to recommend optimizations to the US Nuclear Science Program over the next five years. The study of the properties of hot and dense QCD matter is one of the four main areas of nuclear physics research described in the 2007 NSAC Long Range Plan. The US nuclear physics community plays a leading role in this research area and has been instrumental in its most important discovery made over the past decade, namely that hot and dense QCD matter acts as a strongly interacting system with unique and previously unexpected

416

Suprathermal viscosity of dense matter  

SciTech Connect (OSTI)

Motivated by the existence of unstable modes of compact stars that eventually grow large, we study the bulk viscosity of dense matter, taking into account non-linear effects arising in the large amplitude regime, where the deviation {mu}{sub {Delta}} of the chemical potentials from chemical equilibrium fulfills {mu}{sub {Delta}} > or approx. T. We find that this supra-thermal bulk viscosity can provide a potential mechanism for saturating unstable modes in compact stars since the viscosity is strongly enhanced. Our study confirms previous results on strange quark matter and shows that the suprathermal enhancement is even stronger in the case of hadronic matter. We also comment on the competition of different weak channels and the presence of suprathermal effects in various color superconducting phases of dense quark matter.

Alford, Mark; Mahmoodifar, Simin; Schwenzer, Kai [Department of Physics, Washington University in St. Louis, Missouri, 63130 (United States)

2010-12-22T23:59:59.000Z

417

Physical Protection of Classified Matter  

Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

The order establishes policy and objectives for physical protection of classified matter. This directive does not cancel another directive. Chg 1, 7-30-93. Canceled by 5632.1C.

1988-02-03T23:59:59.000Z

418

What's the matter at RHIC?  

E-Print Network [OSTI]

I present here a concise review of the experimental results obtained at the Relativistic Heavy Ion Collider (RHIC), which shed light on the hot and dense quark gluon matter produced at these high temperature and density conditions.

Raphael Granier de Cassagnac

2007-07-03T23:59:59.000Z

419

Thermally oxidized formation of new Ge dots over as-grown Ge dots in the Si capping layer  

SciTech Connect (OSTI)

A Si-capped Ge quantum dot sample was self-assembly grown via Stranski-Krastanov mode in a molecular beam epitaxy system with the Si capping layer deposited at 300 deg. C. After annealing the sample in an oxygen atmosphere at 1000 deg. C, a structure, namely two layers of quantum dots, was formed with the newly formed Ge-rich quantum dots embedded in the oxidized matrix with the position accurately located upon the as-grown quantum dots. It has been found that the formation of such nanostructures strongly depends upon the growth temperature and oxygen atmosphere. A growth mechanism was proposed to explain the formation of the nanostructure based on the Ge diffusion from the as-grown quantum dots, Ge segregation from the growing oxide, and subsequent migration/agglomeration.

Nie Tianxiao [State Key Laboratory of Surface Physics, Fudan University, Shanghai 200433 (China); Materials Engineering, University of Queensland, Brisbane, Queensland QLD 4072 (Australia); Lin Jinhui; Shao Yuanmin; Wu Yueqin; Yang Xinju; Fan Yongliang; Jiang Zuimin [State Key Laboratory of Surface Physics, Fudan University, Shanghai 200433 (China); Chen Zhigang [Materials Engineering, University of Queensland, Brisbane, Queensland QLD 4072 (Australia); Zou Jin [Materials Engineering, University of Queensland, Brisbane, Queensland QLD 4072 (Australia); Centre for Microscopy and Microanalysis, University of Queensland, Brisbane, Queensland QLD 4072 (Australia)

2011-12-01T23:59:59.000Z

420

Circumscribing late dark matter decays model-independently  

SciTech Connect (OSTI)

A number of theories, spanning a wide range of mass scales, predict dark matter candidates that have lifetimes much longer than the age of the Universe, yet may produce a significant flux of gamma rays in their decays today. We constrain such late-decaying dark matter scenarios model-independently by utilizing gamma-ray line emission limits from the Galactic Center region obtained with the SPI spectrometer on INTEGRAL, and the determination of the isotropic diffuse photon background by SPI, COMPTEL, and EGRET observations. We show that no more than {approx}5% of the unexplained MeV background can be produced by late dark matter decays either in the Galactic halo or cosmological sources.

Yueksel, Hasan; Kistler, Matthew D. [Department of Physics, Ohio State University, Columbus, Ohio 43210 (United States) and Center for Cosmology and Astro-Particle Physics, Ohio State University, Columbus, Ohio 43210 (United States)

2008-07-15T23:59:59.000Z

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


421

Imprint of multicomponent dark matter on AMS-02  

Science Journals Connector (OSTI)

The multicomponent decaying dark matter (DM) scenario is investigated to explain the possible excesses in the positron fraction by PAMELA and recently confirmed by AMS-02, and in the total e++e? flux observed by Fermi-LAT. By performing the ?2 fits, we find that two DM components are already enough to give a reasonable fit of both AMS-02 and Fermi-LAT data. The best-fitted results show that the heavier DM component with its mass of 1.5TeV dominantly decays through the ? channel, while the lighter one of 100GeV decays mainly through the ? channel. As a by-product, the fine structure around 100GeV observed by AMS-02 and Fermi-LAT can be naturally explained by the dropping due to the lighter DM component. With the obtained model parameters by the fitting, we calculate the diffuse ?-ray emission spectrum in this two-component DM scenario, and find that it is consistent with the data measured by Fermi-LAT. We also construct a microscopic particle DM model to naturally realize the two-component DM scenario, and point out an interesting neutrino signal which will possibly be measured in the near future by IceCube.

Chao-Qiang Geng; Da Huang; Lu-Hsing Tsai

2014-03-25T23:59:59.000Z

422

Higgs boson Mass in GMSB with MessengerMatter mixing  

Science Journals Connector (OSTI)

A Higgs-like particle with mass of order 125 GeV has been observed by both ATLAS and CMS experiments. This Higgs mass causes sparticle masses in the several to multi-TeV range in the simple version of minimal GMSB models. We consider the effects of messengermatter mixing on the lightest CPeven Higgs boson mass in gaugemediated supersymmetry breaking models. We find with such mixings a 125 GeV Higgs boson can be naturally obtained even with a subTeV SUSY spectrum, and when the gravitino has a cosmologically preferred subkeV mass. In addition, when these models are embedded into a grand unification framework with a U ( 1 ) flavor symmetry they explain the fermion mass hierarchy and generate naturally large neutrino mixing angles accompanied with small quark mixing angles. While SUSY mediated flavor changing processes are sufficiently suppressed in such an embedding, it can resolve the apparent discrepancy in the CP asymmetry parameters sin 2 ? and ? K , and it predicts an observable ? ? e ? decay rate.

Abdelhamid Albaid

2012-01-01T23:59:59.000Z

423

Combined upper limit for SM Higgs at the Tevatron  

SciTech Connect (OSTI)

We combine results from CDF and D0 on direct searches for a standard model (SM) Higgs boson (H) in p{bar p} collisions at the Fermilab Tevatron at {radical}s = 1.96 TeV. Compared to the previous Higgs Tevatron combination, more data and new channels (WH {yields} {tau}{nu}b{bar b}, VH {yields} {tau}{tau}b{bar b}/jj{tau}{tau}, VH {yields} jjb{bar b}, t{bar t}H {yields} t{bar t}b{bar b}) have been added. Most previously used channels have been reanalyzed to gain sensitivity. We use the latest parton distribution functions and gg {yields} H theoretical cross sections when comparing our limits to the SM predictions. With 2.0-3.6 fb{sup -1} of data analyzed at CDF, and 0.9-4.2 fb{sup -1} at D0, the 95%C.L. upper limits on Higgs boson production are a factor of 2.5 (0.86) times the SM cross section for a Higgs boson mass of m{sub H} = 115 (165) GeV/c{sup 2}. Based on simulation, the corresponding median expected upper limits are 2.4 (1.1). The mass range excluded at 95% C.L. for a SM Higgs has been extended to 160 < m{sub H} < 170 GeV/c{sup 2}.

Penning, Bjorn; /Fermilab

2009-01-01T23:59:59.000Z

424

Demonstration of New Technologies Required for the Treatment of Mixed Waste Contaminated with {ge}260 ppm Mercury  

SciTech Connect (OSTI)

The Resource Conservation and Recovery Act (RCRA) defines several categories of mercury wastes, each of which has a defined technology or concentration-based treatment standard, or universal treatment standard (UTS). RCRA defines mercury hazardous wastes as any waste that has a TCLP value for mercury of 0.2 mg/L or greater. Three of these categories, all nonwastewaters, fall within the scope of this report on new technologies to treat mercury-contaminated wastes: wastes as elemental mercury; hazardous wastes with less than 260 mg/kg [parts per million (ppm)] mercury; and hazardous wastes with 260 ppm or more of mercury. While this report deals specifically with the last category--hazardous wastes with 260 ppm or more of mercury--the other two categories will be discussed briefly so that the full range of mercury treatment challenges can be understood. The treatment methods for these three categories are as follows: Waste as elemental mercury--RCRA identifies amalgamation (AMLGM) as the treatment standard for radioactive elemental mercury. However, radioactive mercury condensates from retorting (RMERC) processes also require amalgamation. In addition, incineration (IMERC) and RMERC processes that produce residues with >260 ppm of radioactive mercury contamination and that fail the RCRA toxicity characteristic leaching procedure (TCLP) limit for mercury (0.20 mg/L) require RMERC, followed by AMLGM of the condensate. Waste with <260 ppm mercury--No specific treatment method is specified for hazardous wastes containing <260 ppm. However, RCRA regulations require that such wastes (other than RMERC residues) that exceed a TCLP mercury concentration of 0.20 mg/L be treated by a suitable method to meet the TCLP limit for mercury of 0.025 mg/L. RMERC residues must meet the TCLP value of {ge}0.20 mg/L, or be stabilized and meet the {ge}0.025 mg/L limit. Waste with {ge}260 ppm mercury--For hazardous wastes with mercury contaminant concentrations {ge}260 ppm and RCRA-regulated organic contaminants (other than incinerator residues), incineration or retorting (IMERC or RMERC) is the treatment standard. For wastes with mercury contaminant concentrations {ge}260 ppm that are inorganic, including incinerator and retort residues, RMERC is the treatment standard. Mercury hazardous waste contaminated with {ge}260 ppm mercury is the primary focus of this report.

Morris, M.I.

2002-02-06T23:59:59.000Z

425

Shear viscosity of nuclear matter  

E-Print Network [OSTI]

In this talk I report my recent study on the shear viscosity of neutron-rich nuclear matter from a relaxation time approach. An isospin- and momentum-dependent interaction is used in the study. Effects of density, temperature, and isospin asymmetry of nuclear matter on its shear viscosity have been discussed. Similar to the symmetry energy, the symmetry shear viscosity is defined and its density and temperature dependence are studied.

Jun Xu

2013-02-01T23:59:59.000Z

426

Lorentz-violating dark matter  

E-Print Network [OSTI]

LORENTZ-VIOLATING DARK MATTER A Dissertation by ANTONIO R. MONDRAGON Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY May 2007 Major Subject...: Physics LORENTZ-VIOLATING DARK MATTER A Dissertation by ANTONIO R. MONDRAGON Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Approved by: Chair...

Mondragon, Antonio Richard

2009-05-15T23:59:59.000Z

427

Ge interactions on HfO{sub 2} surfaces and kinetically driven patterning of Ge nanocrystals on HfO{sub 2}  

SciTech Connect (OSTI)

Germanium interactions are studied on HfO{sub 2} surfaces, which are prepared through physical vapor deposition (PVD) and by atomic layer deposition. X-ray photoelectron spectroscopy and temperature-programed desorption are used to follow the reactions of germanium on HfO{sub 2}. Germanium chemical vapor deposition at 870 K on HfO{sub 2} produces a GeO{sub x} adhesion layer, followed by growth of semiconducting Ge{sup 0}. PVD of 0.7 ML Ge (accomplished by thermally cracking GeH{sub 4} over a hot filament) also produces an initial GeO{sub x} layer, which is stable up to 800 K. PVD above 2.0 ML deposits semiconducting Ge{sup 0}. Temperature programed desorption experiments of {approx}1.0 ML Ge from HfO{sub 2} at 400-1100 K show GeH{sub 4} desorption below 600 K and GeO desorption above 850 K. These results are compared to Ge on SiO{sub 2} where GeO desorption is seen at 550 K. Exploiting the different reactivity of Ge on HfO{sub 2} and SiO{sub 2} allows a kinetically driven patterning scheme for high-density Ge nanoparticle growth on HfO{sub 2} surfaces that is demonstrated.

Stanley, Scott K.; Joshi, Sachin V.; Banerjee, Sanjay K.; Ekerdt, John G. [Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712-0231 (United States); Department of Electrical and Computer Engineering, University of Texas at Austin, Austin, Texas 78712-0240 (United States); Department of Chemical Engineering, University of Texas at Austin, Austin, Texas 78712-0231 (United States)

2006-01-15T23:59:59.000Z

428

Distinct optical properties of relativistically degenerate matter  

SciTech Connect (OSTI)

In this paper, we use the collisional quantum magnetohydrodynamic (CQMHD) model to derive the transverse dielectric function of a relativistically degenerate electron fluid and investigate various optical parameters, such as the complex refractive index, the reflection and absorption coefficients, the skin-depth and optical conductivity. In this model we take into accounts effects of many parameters such as the atomic-number of the constituent ions, the electron exchange, electron diffraction effect and the electron-ion collisions. Study of the optical parameters in the solid-density, the warm-dense-matter, the big-planetary core, and the compact star number-density regimes reveals that there are distinct differences between optical characteristics of the latter and the former cases due to the fundamental effects of the relativistic degeneracy and other quantum mechanisms. It is found that in the relativistic degeneracy plasma regime, such as found in white-dwarfs and neutron star crusts, matter possess a much sharper and well-defined step-like reflection edge beyond the x-ray electromagnetic spectrum, including some part of gamma-ray frequencies. It is also remarked that the magnetic field intensity only significantly affects the plasma reflectivity in the lower number-density regime, rather than the high density limit. Current investigation confirms the profound effect of relativistic degeneracy on optical characteristics of matter and can provide an important plasma diagnostic tool for studying the physical processes within the wide scope of quantum plasma regimes be it the solid-density, inertial-confined, or astrophysical compact stars.

Akbari-Moghanjoughi, M. [Department of Physics, Faculty of Sciences, Azarbaijan Shahid Madani University, Tabriz 51745-406 (Iran, Islamic Republic of); International Centre for Advanced Studies in Physical Sciences and Institute for Theoretical Physics, Ruhr University Bochum, Bochum D-44780 (Germany)

2014-06-15T23:59:59.000Z

429

16 - Microcavities and quantum cascade laser structures based on silicongermanium (SiGe) nanostructures  

Science Journals Connector (OSTI)

Abstract: This chapter discusses two types of Si-based light-emitting devices based on Ge quantum dots in optical microcavities and SiGe quantum cascade (QC) structures. After reviewing various solutions for Si-based light-emitting devices, the chapter describes the method to enhance light emission from Ge dots through embedding them into optical microcavities. It then reviews SiGe quantum cascade laser (QCL) structures on issues of material growth, electroluminescence from SiGe QC structures, n-type SiGe QC structures, and waveguides for SiGe QCLs.

J. Xia; Y. Shiraki; J. Yu

2011-01-01T23:59:59.000Z

430

Direct Detection Constraints on Dark Photon Dark Matter  

E-Print Network [OSTI]

Dark matter detectors built primarily to probe elastic scattering of WIMPs on nuclei are also precise probes of light, weakly coupled particles that may be absorbed by the detector material. In this paper, we derive constraints on the minimal model of dark matter comprised of long-lived vector states V (dark photons) in the 0.01-100 keV mass range. The absence of an ionization signal in direct detection experiments such as XENON10 and XENON100 places a very strong constraint on the dark photon mixing angle, down to $O(10^{-15})$, assuming that dark photons comprise the dominant fraction of dark matter. This sensitivity to dark photon dark matter exceeds the indirect bounds derived from stellar energy loss considerations over a significant fraction of the available mass range. We also revisit indirect constraints from $V\\to 3\\gamma$ decay and show that limits from modifications to the cosmological ionization history are comparable to the updated limits from the diffuse gamma-ray flux.

Haipeng An; Maxim Pospelov; Josef Pradler; Adam Ritz

2014-12-29T23:59:59.000Z

431

A study of an Al-Ge3N4-Ge structure by the method of photo-capacitance-voltage characteristics  

Science Journals Connector (OSTI)

Results are reported of a study of a Ge-Ge3N4...interface by the method of capacitance-voltage characteristics, with the structure irradiated with photons of varied energy. The employed technique revealed trap le...

R. B. Dzhanelidze; M. B. Dzhanelidze; M. R. Katsiashvili

2000-10-01T23:59:59.000Z

432

Invisible Quarkonium Decays as a Sensitive Probe of Dark Matter  

E-Print Network [OSTI]

We examine in a model-independent manner the measurements that can be performed at B-factories with sensitivity to dark matter. If a singlet scalar, pseudo-scalar, or vector is present and mediates the Standard Model - dark matter interaction, it can mediate invisible decays of quarkonium states such as the $\\Upsilon$, $J/\\Psi$, and $\\eta$. Such scenarios have arisen in the context of supersymmetry, extended Higgs sectors, solutions the supersymmetric $\\mu$ problem, and extra U(1) gauge groups from grand unified theories and string theory. Existing B-factories running at the $\\Upsilon(4S)$ can produce lower $\\Upsilon$ resonances by emitting an Initial State Radiation (ISR) photon. Using a combination of ISR and radiative decays, the initial state of an invisibly decaying quarkonium resonance can be tagged, giving sensitivity to the spin and CP-nature of the particle that mediates standard model-dark matter interactions. These measurements can discover or place strong constraints on dark matter scenarios where the dark matter is approximately lighter than the $b$-quark. For the decay chains $\\Upsilon(nS) \\to \\pi^+ \\pi^- \\Upsilon(1S)$ (n=2,3) we analyze the dominant backgrounds and determine that with $400 fb^{-1}$ collected at the $\\Upsilon(4S)$, the B-factories can limit $BR(\\Upsilon(1S) \\to invisible) \\lsim 0.1%$.

Bob McElrath

2005-06-15T23:59:59.000Z

433

VERITAS Upper Limit on the VHE Emission from the Radio Galaxy NGC 1275  

E-Print Network [OSTI]

The recent detection by the Fermi gamma-ray space telescope of high-energy gamma-rays from the radio galaxy NGC 1275 makes the observation of the very high energy (VHE: E > 100 GeV) part of its broadband spectrum particularly interesting, especially for the understanding of active galactic nuclei (AGN) with misaligned multi-structured jets. The radio galaxy NGC 1275 was recently observed by VERITAS at energies above 100 GeV for about 8 hours. No VHE gamma-ray emission was detected by VERITAS from NGC 1275. A 99% confidence level upper limit of 2.1% of the Crab Nebula flux level is obtained at the decorrelation energy of approximately 340 GeV, corresponding to 19% of the power-law extrapolation of the Fermi Large Area Telescope (LAT) result.

Acciari, V A; Arlen, T; Aune, T; Bautista, M; Beilicke, M; Benbow, W; Boltuch, D; Bradbury, S M; Buckley, J H; Bugaev, V; Byrum, K; Cannon, A; Celik, O; Cesarini, A; Ciupik, L; Cogan, P; Cui, W; Dickherber, R; Duke, C; Fegan, S J; Finley, J P; Fortin, P; Fortson, L; Furniss, A; Galante, N; Gall, D; Gibbs, K; Gillanders, G H; Godambe, S; Grube, J; Guenette, R; Gyuk, G; Hanna, D; Holder, J; Horan, D; Hui, C M; Humensky, T B; Imran, A; Kaaret, Philip; Karlsson, N; Kertzman, M; Kieda, D; Konopelko, A; Krawczynski, H; Krennrich, F; Lang, M J; Le Bohec, S; Maier, G; McCann, A; McCutcheon, M; Millis, J; Moriarty, P; Mukherjee, R; Ong, R A; Otte, A N; Pandel, D; Perkins, J S; Pohl, M; Quinn, J; Ragan, K; Reynolds, P T; Roache, E; Rose, H J; Schroedter, M; Sembroski, G H; Smith, A W; Steele, D; Swordy, S P; Theiling, M; Toner, J A; Varlotta, A; Vasilev, V V; Vincent, S; Wagner, R G; Wakely, S P; Ward, J E; Weekes, T C; Weinstein, A; Weisgarber, T; Williams, D A; Wissel, S; Wood, M; Zitzer, B; Kataoka, J; Cavazzuti, E; Cheung, C C; Lott, B; Thompson, D J; Tosti, G

2009-01-01T23:59:59.000Z

434

Fault Current Limiters  

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

Fault Fault Current Limiters Superconducting & Solid-state Power Equipment Office of Electricity Delivery and Energy Reliability www.oe.energy.gov Office of Electricity Delivery and Energy Reliability, OE-1 U.S. Department of Energy - 1000 Independence Avenue, SW - Washington, DC 20585 Plugging America Into the Future of Power What are FCLs? A fault is an unintentional short circuit, or partial short-circuit, in an electric circuit. A variety of factors such as lightning, downed power lines, or crossed power lines cause faults. During a fault, excessive current-called fault current- flows through the electrical system often resulting in a failure of one section of that system by causing a

435

Cryogenic Dark Matter Search (CDMS): The Hunt for Dark Matter  

SciTech Connect (OSTI)

Deciphering the nature of dark matter has great scientific importance. A leading hypothesis is that dark matter is made of Weakly Interactive Massive Particles (WIMPs), which may result from supersymmetry or additional spatial dimensions. The underground search for elastic scattering of WIMPs on suitable targets (the so-called 'direct detection') is currently led by the Cryogenic Dark Matter Search II (CDMS II) experiment. Its sensitivity is ten times better than any other experiment and we hope to obtain another factor ten in the coming two years. After a brief recall of our recent results, I will describe the complementarity between direct detection experiments, the LHC and the ILC and I will outline the role that SLAC could play in this SuperCDMS program.

Sadoulet, Bernard (UC Berkeley) [UC Berkeley

2006-03-06T23:59:59.000Z

436

Results from the Cryogenic Dark Matter Search at Soudan Underground Laboratory  

SciTech Connect (OSTI)

We present results from the Cryogenic Dark Matter Search at Soudan Underground Laboratory for two-tower arrays of detector. Twelve detectors were operated from March 25 to August 8, 2004, or 74.5 detector live days.Within expected background, no statistically significant indication of a WIMP signal was observed. Based on this null observation and combined with our previous results, we exclude a spin-averaged WIMP-nucleon interaction cross section above 1.6 x 10{sup -43} cm{sup 2} for Ge detectors, and 3 x 10{sup -42} cm{sup 2} for Si detectors, for a WIMP mass 60GeV/c{sup 2} with 90%C.L. This result constrains parameter space of minimal supersymmetric standard models (MSSM) and starts to reach the parameter space of a constrained model (CMSSM).

Yoo, Jonghee; /Fermilab

2005-07-01T23:59:59.000Z

437

Probing Dark Matter Self-Interaction in the Sun with IceCube-PINGU  

E-Print Network [OSTI]

We study the capture, annihilation and evaporation of dark matter (DM) inside the Sun. It has been shown that the DM self-interaction can increase the DM number inside the Sun. We demonstrate that this enhancement becomes more significant in the regime of small DM mass, given a fixed DM self-interaction cross section. This leads to the enhancement of neutrino flux from DM annihilation. On the other hand, for DM mass as low as a few GeVs, not only the DM-nuclei scatterings can cause the DM evaporation, DM self-interaction also provides non-negligible contributions to this effect. Consequently, the critical mass for DM evaporation (typically 3 $\\sim$ 4 GeV without the DM self-interaction) can be slightly increased. We discuss the prospect of detecting DM self-interaction in IceCube-PINGU using the annihilation channels $\\chi\\chi \\rightarrow \\tau^{+}\\tau^{-}, \

Chian-Shu Chen; Fei-Fan Lee; Guey-Lin Lin; Yen-Hsun Lin

2014-11-20T23:59:59.000Z

438

What can HELIOS tell us on phase transition of nuclear matter  

SciTech Connect (OSTI)

Transverse energy (E/sub t/) distributions and P/sub t/ spectra of negative particles and photons measured by the HELIOS experiment in 200 GeVN and 60 GeVN oxygen-nucleus reactions are presented. The E/sub t/ distributions are compared to a geometrical parametrization and a Montereverse arrowCarlo calculation, particle spectra to the proton-nucleus reaction case. The comparisons show that yet the results can be understood without assuming quark-gluon plasma formation. A discussion is made based on these comparisons together with an estimate of the energy density of the reaction, attempting to know how close we are to the detection of a phase transition of nuclear matter. 21 refs., 15 figs.

En'yo, H.

1987-01-01T23:59:59.000Z

439

Viscosity of meson matter  

Science Journals Connector (OSTI)

We report a calculation of the shear viscosity in a relativistic multicomponent meson gas as a function of temperature and chemical potentials. We approximately solve the Uehling-Uhlenbeck transport equation of kinetic theory, appropriate for a boson gas, with relativistic kinematics. Since at low temperatures the gas can be taken as mostly composed of pions, with a fraction of kaons and etas, we explore the region where binary elastic collisions with at least one pion are the dominant scattering processes. Our input meson scattering phase shifts are fits to the experimental data obtained from chiral perturbation theory and the inverse amplitude method. Our results take the correct nonrelativistic limit (viscosity proportional to the square root of the temperature), show a viscosity of the order of the cube of the pion mass up to temperatures somewhat below that mass, and then a large increase due to kaons and etas. Our approximation may break down at even higher temperatures, where the viscosity follows a temperature power law with an exponent near 3.

Antonio Dobado and Felipe J. Llanes-Estrada

2004-06-29T23:59:59.000Z

440

From Strings Theory to the Dark Matter in Galaxies  

E-Print Network [OSTI]

Starting from the effective action of the low energy limit of superstrings theory, I find an exact solution of the field equations which geodesics behavie exactly as the trajectories of stars arround of a spiral galaxy. Here dark matter is of dilatonic origin. It is remarkable that the energy density of this space-time is the same as the used by astronomers to model galaxy stability. Some remarks about a universe dominated by dilatons are pointed out.

Tonatiuh Matos

1999-05-04T23:59:59.000Z

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


441

On the Al-Si, Al-Ge, and Al-Ge-Si systems and their application to brazing in high power semiconductor devices  

Science Journals Connector (OSTI)

Results of the Smith thermal analysis studies13 of the Al-Si, Al-Ge, and Al-Ge-Si systems are presented and compared with ... . Isothermal and vertical sections for the Al-Ge-Si system, computed from thermodynami...

F. H. Hayes; R. D. Longbottom; E. Ahmad; G. Chen

1993-08-01T23:59:59.000Z

442

Electron spin resonance observation of an interfacial Ge  

Science Journals Connector (OSTI)

Using electron spin resonance (ESR), we report on the observation of a first Ge dangling bond (DB)-type interface defect in the SiO2/(100)GexSi1?x/SiO2/(100)Si heterostructure manufactured by the condensation technique. The center, exhibiting monoclinic-I (C2v) symmetry with principal g values g1 = 2.0338 0.0003, g2 = 2.0386 0.0006, g3 = 2.0054 is observed in maximum densities of ~6.8 ? 1012cm?2 of the GexSi1?x/SiO2 interface for x~0.7, the signal disappearing for x outside the 0.450.93 range. The notable absence of interfering Si Pb-type centers enables unequivocal spectral analysis. Collectively, the combination of all data leads to depicting the defect as a Ge Pb 1-type center, i.e.not a trigonal basic Ge Pb(0)-type center (). Understanding the modalities of the defect's occurrence may provide an insight into the thus far elusive role of Ge DB defects at Ge/insulator interfaces, and widen our understanding of interfacial DB centers in general.

A Stesmans; P Somers; V V Afanas'ev

2009-01-01T23:59:59.000Z

443

Mrk 421, Mrk 501, and 1ES 1426+428 at 100 GeV with the CELESTE Cherenkov Telescope  

E-Print Network [OSTI]

We have measured the gamma-ray fluxes of the blazars Mrk 421 and Mrk 501 in the energy range between 50 and 350 GeV (1.2 to 8.3 x 10^25 Hz). The detector, called CELESTE, used first 40, then 53 heliostats of the former solar facility "Themis" in the French Pyrenees to collect Cherenkov light generated in atmospheric particle cascades. The signal from Mrk 421 is often strong. We compare its flux with previously published multi-wavelength studies and infer that we are straddling the high energy peak of the spectral energy distribution. The signal from Mrk 501 in 2000 was weak (3.4 sigma). We obtain an upper limit on the flux from 1ES 1426+428 of less than half that of the Crab flux near 100 GeV. The data analysis and understanding of systematic biases have improved compared to previous work, increasing the detector's sensitivity.

D. A. Smith; E. Brion; R. Britto; P. Bruel; J. Bussons Gordo; D. Dumora; E. Durand; P. Eschstruth; P. Espigat; J. Holder; A. Jacholkowska; J. Lavalle; R. Le Gallou; B. Lott; H. Manseri; F. Munz; E. Nuss; F. Piron; R. C. Rannot; T. Reposeur; T. Sako

2006-08-11T23:59:59.000Z

444

Mrk 421, Mrk 501, and 1ES 1426+428 at 100 GeV with the CELESTE Cherenkov Telescope  

E-Print Network [OSTI]

We have measured the gamma-ray fluxes of the blazars Mrk 421 and Mrk 501 in the energy range between 50 and 350 GeV (1.2 to 8.3 x 10^25 Hz). The detector, called CELESTE, used first 40, then 53 heliostats of the former solar facility "Themis" in the French Pyrenees to collect Cherenkov light generated in atmospheric particle cascades. The signal from Mrk 421 is often strong. We compare its flux with previously published multi-wavelength studies and infer that we are straddling the high energy peak of the spectral energy distribution. The signal from Mrk 501 in 2000 was weak (3.4 sigma). We obtain an upper limit on the flux from 1ES 1426+428 of less than half that of the Crab flux near 100 GeV. The data analysis and understanding of systematic biases have improved compared to previous work, increasing the detector's sensitivity.

Smith, D A; Britto, R; Bruel, P; Gordo, J B; Dumora, D; Durand, E; Eschstruth, P; Espigat, P; Holder, J; Jacholkowska, A; Lavalle, J; Le Gallou, R; Lott, B; Manseri, H; Munz, F; Nuss, E; Piron, Frdric; Reposeur, T; Sako, T

2006-01-01T23:59:59.000Z

445

Dark Matter in Minimal Universal Extra Dimensions with a Stable Vacuum and the "Right" Higgs  

E-Print Network [OSTI]

The recent discovery of a Higgs boson with mass of about 125 GeV, along with its striking similarity to the prediction from the Standard Model, informs and constrains many models of new physics. The Higgs mass exhausts one out of three input parameters of the minimal, five-dimensional version of universal extra dimension models, the other two parameters being the Kaluza-Klein (KK) scale and the cut-off scale of the theory. The presence of KK fermions with large coupling to the Higgs implies a short-lived electro-weak vacuum, unless the cut-off scale is at most a few times higher than the KK mass scale, providing an additional tight constraint to the theory parameter space. Here, we focus on the lightest KK particle as a dark matter candidate, and investigate the regions of parameter space where such particle has a thermal relic density in accord with the cosmological dark matter density. We find the paradoxical result that, for low enough cutoff scales consistent with vacuum stability, larger than previously thought KK mass scales become preferred to explain the dark matter abundance in the universe. We explain this phenomenon by pinpointing the additional particles which, at such low cutoffs, become close enough in mass to the dark matter candidate to coannihilate with it. We make predictions for both collider and direct dark matter searches that might soon close in on all viable theory parameter space.

Jonathan M. Cornell; Stefano Profumo; William Shepherd

2014-01-27T23:59:59.000Z

446

Fermion WIMPless dark matter at DeepCore and IceCube  

Science Journals Connector (OSTI)

We investigate the prospects for indirect detection of fermion WIMPless dark matter at the neutrino telescopes IceCube and DeepCore. The dark matter annihilating in the Sun is a hidden sector Majorana fermion that couples through Yukawa couplings to a connector particle and a visible sector particle, and it exhibits only spin-dependent scattering with nuclei via couplings to first generation quarks. We consider cases where the annihilation products are taus, staus, or sneutrinos of the three generations. To evaluate the muon fluxes incident at the detector, we propagate the neutrino spectra through the solar medium and to the Earth and account for the effects of neutrino oscillations, energy losses due to neutral- and charged-current interactions, and tau regeneration. We find that for the stau and sneutrino channels, a 5yr 3? detection of dark matter lighter than about 300GeV is possible at IceCube for large Yukawa couplings or for dark matter and connector particles with similar masses. The tau channel offers far better detection prospects. However, due to its lower energy threshold and better muon background rejection capability, DeepCore is able to detect signals in all annihilation channels and for a wider range of dark matter masses.

Vernon Barger; Jason Kumar; Danny Marfatia; Enrico Maria Sessolo

2010-06-24T23:59:59.000Z

447

Energy Gap in Nuclear Matter  

Science Journals Connector (OSTI)

The magnitude of the energy gap in nuclear matter associated with a highly correlated ground state of of the type believed to be important in the theory of superconductivity has been evaluated theoretically. The integral equation of Cooper, Mills, and Sessler is linearized and transformed into a form suitable for numerical solution. The energy gap, calculated by using an appropriate single-particle potential and the Gammel-Thaler two-body potential, is found to be a very strong function of the density of nuclear matter, and of the effective mass at the Fermi surface. It is concluded that the magnitude of the energy gap for nuclear matter should not be compared directly with experimental values for finite nuclei, although the results suggest that if the theory is extended to apply to finite nuclei it probably would be in agreement with experiment.

V. J. Emery and A. M. Sessler

1960-07-01T23:59:59.000Z

448

Cedar Creek Wind Farm I (GE) | Open Energy Information  

Open Energy Info (EERE)

GE) GE) Jump to: navigation, search Name Cedar Creek Wind Farm I (GE) Facility Cedar Creek Sector Wind energy Facility Type Commercial Scale Wind Facility Status In Service Owner Babcock & Brown/BP America Developer Babcock & Brown/BP America Energy Purchaser Xcel Energy Location Weld County east of Grover CO Coordinates 40.873578°, -104.07825° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":40.873578,"lon":-104.07825,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

449

Greenhouse Gas Services AES GE EFS | Open Energy Information  

Open Energy Info (EERE)

Greenhouse Gas Services AES GE EFS Greenhouse Gas Services AES GE EFS Jump to: navigation, search Name Greenhouse Gas Services (AES/GE EFS) Place Arlington, Virginia Zip 22203-4168 Product Develop and invest in a range of projects that reduce greenhouse gas emissions that produce verified GHG credits. Coordinates 43.337585°, -89.379449° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":43.337585,"lon":-89.379449,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

450

Top of the World (GE) | Open Energy Information  

Open Energy Info (EERE)

Top of the World (GE) Top of the World (GE) Facility Top of the World (GE) Sector Wind energy Facility Type Commercial Scale Wind Facility Status In Service Owner Duke Energy Carolinas LLC Developer Duke Energy Carolinas LLC Energy Purchaser PacifiCorp Location 4 miles northeast of Glenrock WY Coordinates 42.914132°, -105.691223° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":42.914132,"lon":-105.691223,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

451

NETL: News Release - GE Sets Benchmarks for Fuel Cell Performance  

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

August 8, 2005 August 8, 2005 GE Sets Benchmarks for Fuel Cell Performance Achievements Move Efficient, Clean SOFC Technology Closer to Mainstream Energy Markets TORRANCE, CA - In the race to speed solid oxide fuel cell (SOFC) technology out of niche markets and into widespread commercial use, GE Hybrid Power Generation Systems has kicked fuel cell performance into high gear. Recent advancements have dramatically improved baseline cell performance and accelerate GE's prospects for achieving the system efficiency and cost objectives of DOE's Solid State Energy Alliance (SECA) program. Packing more power into smaller volumes is one of the breakthroughs needed to reduce the cost and expand the use of efficient, environmentally friendly fuel cells. But increasing power density isn't the only goal; as power density increases, fuel cells must continue to efficiently and reliably convert fuel to electric power.

452

Tunneling states in vitreous GeO2s  

Science Journals Connector (OSTI)

Ultrasonic measurements of the attenuation and the velocity variation have been carried out in amorphous GeO2 at low temperature (0.310 K) and high frequencies (80210 MHz). From numerical fits to the tunneling model, the typical parameters of the tunneling states (TS) were determined and compared to those found for vitreous SiO2 . The study reveals that in a-GeO2 , which is considered as a close structural analog to a-SiO2 , although the density of states is found to be very similar in both materials, the coupling between the TS and the phonons is significantly smaller. In the model of coupled tetrahedra as the origin of the TS, this difference can be understood in view of the fact that numerical calculations about the vibrational characteristics of network amorphous solids indicate that the tetrahedra are more decoupled in vitreous GeO2 than in vitreous silica.

Christiane Laermans; Veerle Keppens; Robert Weeks

1997-02-01T23:59:59.000Z

453

Matters on a moving brane  

E-Print Network [OSTI]

A novel generalisation of the Dirac-Born-Infeld string scenario is described. It is shown that matter residing on the moving brane is dark and has the so-called disformal coupling to gravity. This gives rise to cosmologies where dark matter stems from the oscillations of the open strings along the brane and the transverse oscillations result in dark energy. Furthermore, due to a new screening mechanism that conceals the fifth force from local experiments, one may even entertain the possibility that the visible sector is also moving along the extra dimensions.

Tomi Sebastian Koivisto; Danielle Elizabeth Wills

2013-12-12T23:59:59.000Z

454

FED pumped limiter configuration issues  

SciTech Connect (OSTI)

Impurity control in the Fusion Engineering Device (FED) is provided by a toroidal belt pumped limiter. Limiter design issues addressed in this paper are (1) poloidal location of the limiter belt, (2) shape of the limiter surface facing the plasma, and (3) whether the belt is pumped from one or both sides. The criteria used for evaluation of limiter configuration features were sensitivity to plasma-edge conditions and ease of maintenance and fabrication. The evaluation resulted in the selection of a baseline FED limiter that is located at the bottom of the device and has a flat surface with a single leading edge.

Haines, J.R.; Fuller, G.M.

1983-01-01T23:59:59.000Z

455

Searching for Dark Matter with X-Ray Observations of Local Dwarf Galaxies  

Science Journals Connector (OSTI)

A generic feature of weakly interacting massive particle (WIMP) dark matter models is the emission of photons over a broad energy band resulting from the stable yields of dark matter pair annihilation. Inverse Compton scattering off cosmic microwave background photons of energetic electrons and positrons produced in dark matter annihilation is expected to produce significant diffuse X-ray emission. Dwarf galaxies are ideal targets for this type of dark matter search technique, being nearby, dark matter dominated systems free of any astrophysical diffuse X-ray background. In this paper, we present the first systematic study of X-ray observations of local dwarf galaxies aimed at the search for WIMP dark matter. We outline the optimal energy and angular ranges for current telescopes and analyze the systematic uncertainties connected to electron/positron diffusion. We do not observe any significant X-ray excess, and we translate this null result into limits on the mass and pair annihilation cross section for particle dark matter. Our results indicate that X-ray observations of dwarf galaxies currently constrain dark matter models at the same level as or even more strongly than gamma-ray observations of the same systems, although at the expenses of introducing additional assumptions and related uncertainties in the modeling of diffusion and energy loss processes. The limits we find constrain portions of the supersymmetric parameter space, particularly if the effect of dark matter substructures is included. Finally, we comment on the role of future X-ray satellites (e.g., Constellation-X, XEUS) and on their complementarity with GLAST and other gamma-ray telescopes in the quest for particle dark matter.

T. E. Jeltema; S. Profumo

2008-01-01T23:59:59.000Z

456

Universal Ownership: Why Environmental Externalities Matter to  

Open Energy Info (EERE)

Universal Ownership: Why Environmental Externalities Matter to Universal Ownership: Why Environmental Externalities Matter to Institutional Investors Jump to: navigation, search Tool Summary Name: Universal Ownership: Why Environmental Externalities Matter to Institutional Investors Agency/Company /Organization: UNEP-Financing Initiative Focus Area: Industry Topics: Co-benefits assessment Resource Type: Lessons learned/best practices Website: www.unepfi.org/fileadmin/documents/universal_ownership.pdf Universal Ownership: Why Environmental Externalities Matter to Institutional Investors Screenshot References: Universal Ownership: Why Environmental Externalities Matter to Institutional Investors[1] Logo: Universal Ownership: Why Environmental Externalities Matter to Institutional Investors Summary "This study assesses the financial implications of unsustainable natural

457

Phi Meson in Dense Matter  

E-Print Network [OSTI]

The effect of the kaon loop correction to the property of a phi meson in dense matter is studied in the vector dominance model. Using the density-dependent kaon effective mass determined from the linear chiral perturbation theory, we find...

Ko, Che Ming; Levai, P.; Qiu, X. J.; Li, C. T.

1992-01-01T23:59:59.000Z

458

Solar Neutrino Matter Effects Redux  

E-Print Network [OSTI]

Following recent low-threshold analysis of the Sudbury Neutrino Observatory and asymmetry measurements of the BOREXINO Collaboration of the solar neutrino flux, we revisit the analysis of the matter effects in the Sun. We show that solar neutrino data constrains the mixing angle $\\theta_{13}$ poorly and that subdominant Standard Model effects can mimic the effects of the physics beyond the Standard Model.

A. B. Balantekin; A. Malkus

2011-12-19T23:59:59.000Z

459

The Information and the Matter  

E-Print Network [OSTI]

In this article a revised, to some extent, version of the Information concept as utmost fundamental essence ("The Information and the Matter",v1) is presented - a little more logical grounds and may be of a philosophy, the correction and the development of the gravity force concept, etc...

S. V. Shevchenko; V. V. Tokarevsky

2007-03-05T23:59:59.000Z

460

Time-resolved photoluminescence from self-assembled Ge(Si) islands in multilayer SiGe/Si and SiGe/SOI structures  

SciTech Connect (OSTI)

The results of a study of the spectral and temporal characteristics of the photoluminescence (PL) from multilayer structures with self-assembled Ge(Si) islands grown on silicon and 'silicon-on-insulator' substrates in relation to temperature and the excitation-light wavelength are presented. A substantial increase in island-related PL intensity is observed for structures with Ge(Si) islands grown on silicon substrates upon an increase in temperature from 4 to 70 K. This increase is due to the diffusion of nonequilibrium carriers from the silicon substrate into the active layer with the islands. In this case, a slow component with a characteristic time of {approx}100 ns appears in the PL rise kinetics. At the same time, no slow component in the PL rise kinetics and no rise in the PL intensity with increasing temperature are observed for structures grown on 'silicon-on-insulator' substrates, in which the active layer with the islands is insulated from the silicon substrate. It is found that absorption of the excitation light in the islands and SiGe wetting layers mainly contributes to the excitation of the PL signal from the islands under sub-bandgap optical pump conditions.

Yablonskiy, A. N., E-mail: yablonsk@ipm.sci-nnov.ru; Baidakova, N. A. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation)] [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation); Novikov, A. V. [Lobachevskyi University of Nizhni Novgorod, Physical-Technical Research Institute (Russian Federation)] [Lobachevskyi University of Nizhni Novgorod, Physical-Technical Research Institute (Russian Federation); Lobanov, D. N. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation)] [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation)

2013-11-15T23:59:59.000Z

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


461

Low-background underground facilities for the direct detection of dark matter  

SciTech Connect (OSTI)

This is the report of a working group formed to discuss the requirements of an underground facility for experiments trying to detect directly dark matter particles. There is a brief discussion of the general properties of underground facilities, focusing on the levels of muon induced backgrounds that are tolerable. Then the authors review the scientific motivation of the search for dark matter particles, and the existing experimental limits. There is a short description of the shielding necessary to reach the desired background levels. Finally, they report the results of their preliminary study of muon induced backgrounds in dark matter experiments, and the implications for the required depth of the facilities for such experiments.

Barnes, P.D. Jr. [Univ. of California, Berkeley, CA (United States); [Center for Particle Astrophysics, Berkeley, CA (United States); Caldwell, D. [Univ. of California, Santa Barbara, CA (United States); DaSilva, A. [Center for Particle Astrophysics, Berkeley, CA (United States)] [and others

1992-12-31T23:59:59.000Z

462

Alliance fights limits on chlorofluorocarbons  

Science Journals Connector (OSTI)

Alliance fights limits on chlorofluorocarbons ... Efforts by the nascent Alliance for Responsible CFC Policy to curb the Environmental Protection Agency's plans to put more limits on chlorofluorocarbons are beginning to have results. ... The 400-member alliance was formed last August to fight EPA's avowed intention to limit production of CFC's in the U.S. to 30% of their present levels. ...

1981-03-02T23:59:59.000Z

463

Cedar Creek Wind Farm II (GE) | Open Energy Information  

Open Energy Info (EERE)

Cedar Creek Wind Farm II (GE) Cedar Creek Wind Farm II (GE) Jump to: navigation, search Name Cedar Creek Wind Farm II (GE) Facility Cedar Creek II (GE) Sector Wind energy Facility Type Commercial Scale Wind Facility Status In Service Owner BP Wind Energy Developer BP Wind Energy Energy Purchaser Xcel Energy Location Weld County CO Coordinates 40.868652°, -104.092398° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":40.868652,"lon":-104.092398,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

464

12 GeV detector technology at Jefferson Lab  

SciTech Connect (OSTI)

The Thomas Jefferson National Accelerator Facility (JLab) is presently in the middle of an upgrade to increase the energy of its CW electron beam from 6 GeV to 12 GeV along with the addition of a fourth experimental hall. Driven both by necessity and availability, novel detectors and electronics modules have been used in the upgrade. One such sensor is the Silicon Photomultiplier (SiPM), specifically a Multi-Pixel Photon Counter (MPPC), which is an array of avalanche photodiode pixels operating in Geiger mode that are used to sense photons. The SiPMs replace conventional photomultiplier tubes and have several distinct advantages including the safe operation in a magnetic field and the lack of need for high voltage. Another key to 12 GeV success is advanced fast electronics. Jlab will use custom 250 MHz and 125 MHz 12-bit analog to digital converters (ADCs) and time to digital converters (TDCs) all of which take advantage of VME Switched Serial (VXS) bus with its GB/s high bandwidth readout capability. These new technologies will be used to readout drift chambers, calorimeters, spectrometers and other particle detectors at Jlab once the 12 GeV upgrade is complete. The largest experiment at Jlab utilizing these components is GlueX - an experiment in the newly constructed Hall D that will study the photoproduction of light mesons in the search for hybrid mesons. The performance of these components and their respective detectors will be presented.

Leckey, John P. [Indiana U.

2013-04-01T23:59:59.000Z

465

12 GeV detector technology at Jefferson Lab  

SciTech Connect (OSTI)

The Thomas Jefferson National Accelerator Facility (JLab) is presently in the middle of an upgrade to increase the energy of its CW electron beam from 6 GeV to 12 GeV along with the addition of a fourth experimental hall. Driven both by necessity and availability, novel detectors and electronics modules have been used in the upgrade. One such sensor is the Silicon Photomultiplier (SiPM), specifically a Multi-Pixel Photon Counter (MPPC), which is an array of avalanche photodiode pixels operating in Geiger mode that are used to sense photons. The SiPMs replace conventional photomultiplier tubes and have several distinct advantages including the safe operation in a magnetic field and the lack of need for high voltage. Another key to 12 GeV success is advanced fast electronics. Jlab will use custom 250 MHz and 125 MHz 12-bit analog to digital converters (ADCs) and time to digital converters (TDCs) all of which take advantage of VME Switched Serial (VXS) bus with its GB/s high bandwidth readout capability. These new technologies will be used to readout drift chambers, calorimeters, spectrometers and other particle detectors at Jlab once the 12 GeV upgrade is complete. The largest experiment at Jlab utilizing these components is GlueX - an experiment in the newly constructed Hall D that will study the photoproduction of light mesons in the search for hybrid mesons. The performance of these components and their respective detectors will be presented.

Leckey, John P. [Indiana University, Bloomington, IN 47405 (United States); Collaboration: GlueX Collaboration

2013-04-19T23:59:59.000Z

466

Charm Photoproduction Cross Section at 20 GeV  

Science Journals Connector (OSTI)

Forty-seven charm events have been observed in an exposure of the SLAC Hybrid Facility bubble chamber to a 20-GeV backward-scattered laser beam. Thirty-seven events survive all the necessary cuts imposed. Based on this number the total charm cross section is calculated to be 63-28+33 nb.

K. Abe et al. ((Stanford Linear Accelerator Center Hybrid Facility Photon Collaboration))

1983-07-18T23:59:59.000Z

467

SiGeCSi superlattice microcoolers Xiaofeng Fan,a)  

E-Print Network [OSTI]

stabilization of microelectronic and optoelectronic devices. SiGeC can be lattice matched to Si and optoelectronic devices, but their pro- cessing is a bulk technology and is incompatible with inte- grated circuit fabrication process. Solid-state coolers mono- lithically integrated with microelectronic and optoelectronic

468

Radiation effects in Si-Ge quantum size structure (Review)  

SciTech Connect (OSTI)

The article is dedicated to the review and analysis of the effects and processes occurring in Si-Ge quantum size semiconductor structures upon particle irradiation including ion implantation. Comparisons to bulk materials are drawn. The reasons of the enhanced radiation hardness of superlattices and quantum dots are elucidated. Some technological applications of the radiation treatment are reviewed.

Sobolev, N. A., E-mail: sobolev@ua.pt [Universidade de Aveiro, Departamento de Fisica and I3N (Portugal)

2013-02-15T23:59:59.000Z

469

On the Production of $?^+?^+$ Pairs in pp Collisions at 0.8 GeV  

E-Print Network [OSTI]

Data accumulated recently for the exclusive measurement of the $pp\\to pp\\pi^+\\pi^-$ reaction at a beam energy of 0.793 GeV using the COSY-TOF spectrometer have been analyzed with respect to possible events from the $pp \\to nn\\pi^+\\pi^+$ reaction channel. The latter is expected to be the only $\\pi\\pi$ production channel, which contains no major contributions from resonance excitation close to threshold and hence should be a good testing ground for chiral dynamics in the $\\pi\\pi$ production process. No single event has been found, which meets all conditions for being a candidate for the $pp \\to nn \\pi^+\\pi^+$ reaction. This gives an upper limit for the cross section of 0.16 $\\mu$b (90% C.L.), which is more than an order of magnitude smaller than the cross sections of the other two-pion production channels at the same incident energy.

S. Abd El-Samad; R. Bilger; K. -Th. Brinkmann; H. Clement; M. Dietrich; E. Doroshkevich; S. Dshemuchadse; K. Ehrhardt; A. Erhardt; W. Eyrich; A. Filippi; H. Freiesleben; M. Fritsch; R. Geyer; A. Gillitzer; J. Hauffe; D. Hesselbarth; R. Jaekel; B. Jakob; L. Karsch; K. Kilian; J. Kress; E. Kuhlmann; S. Marcello; S. Marwinski; R. Meier; K. Moeller; H. P. Morsch; L. Naumann; J. Ritman; E. Roderburg; P. Schoenmeier M. Schulte-Wissermann; W. Schroeder; F. Stinzing; G. Y. Sun; J. Waechter; G. J. Wagner M. Wagner; U. Weidlich; A. Wilms; S. Wirth; G. Zhang; P. Zupranski

2009-06-17T23:59:59.000Z

470

A possible indication of momentum-dependent asymmetric dark matter in the Sun  

E-Print Network [OSTI]

Broad disagreement persists between helioseismological observables and predictions of solar models computed with the latest surface abundances. Here we show that most of these problems can be solved by the presence of asymmetric dark matter coupling to nucleons as the square of the momentum $q$ exchanged in the collision. We compute neutrino fluxes, small frequency separations, surface helium abundances, sound speed profiles and convective zone depths for a number of models, showing more than a $6\\sigma$ preference for $q^2$ models over others, and over the Standard Solar Model. The preferred mass (3 GeV) and reference dark matter-nucleon cross-section ($10^{-37}$ cm$^2$ at $q_0 = 40$ MeV) are within the region of parameter space allowed by both direct detection and collider searches.

Aaron C. Vincent; Pat Scott; Aldo Serenelli

2014-11-24T23:59:59.000Z

471

Nuclear matter to strange matter transition in holographic QCD  

E-Print Network [OSTI]

We construct a simple holographic QCD model to study nuclear matter to strange matter transition. The interaction of dense medium and hadrons is taken care of by imposing the force balancing condition for stable D4/D6/D6 configuration. By considering the intermediate and light flavor branes interacting with baryon vertex homogeneously distributed along R^3 space and requesting the energy minimization, we find that there is a well defined transition density as a function of current quark mass. We also find that as density goes up very high, intermediate (or heavy) and light quarks populate equally as expected from the Pauli principle. In this sense, the effect of the Pauli principle is realized as dynamics of D-branes.

Youngman Kim; Yunseok Seo; Sang-Jin Sin

2009-11-19T23:59:59.000Z

472

Self-assembling of Ge quantum dots in the CaF2/Ge/CaF2/Si heteroepitaxial system and the development of tunnel-resonance diode on its basis  

Science Journals Connector (OSTI)

A CaF2/Ge/CaF2/Si(111) heteroepitaxial structure with Ge quantum dots was grown by molecular-beam ... , is 4050 meV depending on the Ge dot size.

L. V. Sokolov; A. S. Deryabin; A. I. Yakimov

2004-01-01T23:59:59.000Z

473

Cold quark matter in compact stars  

SciTech Connect (OSTI)

We used an equation of state for the cold quark matter to the study of properties of quark stars. We also discuss the absolute stability of quark matter and compute the mass-radius relation for self-bound stars.

Franzon, B.; Fogaca, D. A.; Navarra, F. S. [Instituto de Fisica, Universidade de Sao Paulo Rua do Matao, Travessa R, 187, 05508-090 Sao Paulo, SP (Brazil); Horvath, J. E. [Instituto de Astronomia, Geofisica e Ciencias Atmosfericas, Universidade de Sao Paulo, Rua do Matao, 1226, 05508-090, Sao Paulo, SP (Brazil)

2013-03-25T23:59:59.000Z

474

Condensed Matter Theory Center Wednesday, May 18  

E-Print Network [OSTI]

Condensed Matter Theory Center Seminar Wednesday, May 18 11am-12pm 2205 Physics Building Zhengcheng condensed matter physics is based on two theories: symmetry breaking theory for phases and phase transitions

Lathrop, Daniel P.

475

Condensed Matter Theory Center/JQI  

E-Print Network [OSTI]

Joint Condensed Matter Theory Center/JQI Seminar Wednesday, March 21, 11:00-12:30pm 2205 Physics in condensed matter physics. Among the exciting recent developments in this direction are the discoveries

Lathrop, Daniel P.

476

Condensed Matter Theory Center Tuesday, December 13  

E-Print Network [OSTI]

Condensed Matter Theory Center Seminar Tuesday, December 13 11:00am-12:30pm 2205 Physics Building" Abstract: At sufficiently low temperatures, condensed-matter systems tend to develop order. An notable

Lathrop, Daniel P.

477

Theory, phenomenology, and prospects for detection of supersymmetric dark matter  

Science Journals Connector (OSTI)

One of the great attractions of minimal superunified supersymmetric models is the prediction of a massive, stable, weakly interacting particle [the lightest supersymmetric partner (LSP)] which can have the right relic abundance to be a cold dark matter candidate. In this paper we investigate the identity, mass, and properties of the LSP after requiring gauge coupling unification, proper electroweak symmetry breaking, and numerous phenomenological constraints. We then discuss the prospects for detecting the LSP. The experiments which we investigate are (1) space annihilations into positrons, antiprotons, and ? rays, (2) large underground arrays to detect upward-going muons arising from LSP capture and annihilation in the sun and earth, (3) elastic collisions on matter in a table top apparatus, and (4) production of LSPs or decays into LSPs at high energy colliders. Our conclusions are that space annihilation experiments and large underground detectors are of limited help in initially detecting the LSP although perhaps they could provide confirmation of a signal seen in other experiments, while table top detectors have considerable discovery potential. Colliders such as the CERN LEP II, an upgraded Fermilab, and the CERN LHC might be the best dark matter detectors of all. This paper improves on most previous analyses in the literature by (a) only considering parameters not already excluded by several physics constraints listed above, (b) presenting results that are independent of (usually untenable) parameter choices, (c) comparing opportunities to study the same cold dark matter, and (d) including minor technical improvements.

E. Diehl; G. L. Kane; Chris Kolda; James D. Wells

1995-10-01T23:59:59.000Z

478