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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
DOE OSTI2011

Strategy for studying {nu}{sub {mu}} CCQE interactions in the T2K near detector

The T2K (Tokai-to-Kamioka) experiment is a long-baseline neutrino oscillation experiment, currently operating in Japan, aiming at measuring the {theta}{sub 13} mixing angle. It uses an intense off-axis beam of mainly muon neutrinos incident on the Super-Kamiokande detector. The off-axis near detector complex, ND280, can be used to perform charge current quasi-elastic (CCQE) measurements, that define the flux normalization and predict the unoscillated spectrum. The strategy for studying {nu}{sub {mu}} CCQE interactions in the ND280 detector is described, together with the first inclusive charge current results from the first period of T2K operation.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2011

Radiation Shielding Properties of Some Marbles in Turkey

Especially after development of technology, radiation started to be used in a large fields such as medicine, industry and energy. Using radiation in those fields bring hazardous effect of radiation into humancell. Thus radiation protection becomes important in physics. Although there are three ways for radiation protection, shielding of the radiation is the most commonly used method. Natural Stones such as marble is used as construction material especially in critical building and thus its radiation shielding capability should be determined.In this study, gamma ray shielding properties of some different types of marble mined in Turkey, have been measured using a NaI(Tl) scintillator detector. The measured results were also compared with the theoretical calculations XCOM.

61 RADIATION PROTECTION AND DOSIMETRY↗
DOE OSTI2011

Approaches for III/V Photonics on Si

We investigated different approaches to overcome difficulties in III/V-on-Si heteroepitaxy, namely growth on compliant substrates and virtual Ge substrates, both realized on top of Si substrates, and in addition, directly on Si. The prospect of this work was the realization of a light emitter on standard Si(100) substrate, capable of being integrated in established industrial processes.

36 MATERIALS SCIENCE↗
DOE OSTI2011

Fano Resonance in GaAs 2D Photonic Crystal Nanocavities

We report the results of polarization resolved reflectivity experiments in GaAs air-bridge photonic crystals with L3 cavities. We show that the fundamental L3 cavity mode changes, in a controlled way, from a Lorentzian symmetrical lineshape to an asymmetrical form when the linear polarization of the incident light is rotated in the plane of the crystal. The different lineshapes are well fitted by the Fano asymmetric equation, implying that a Fano resonance is present in the reflectivity. We use the scattering matrix method to model the Fano interference between a localized discrete state (the cavity fundamental mode) and a background of continuum states (the light reflected from the crystal slab in the vicinity of the cavity) with very good agreement with the experimental data.

36 MATERIALS SCIENCE↗
DOE OSTI2011

Generation and decay of entanglement in exciton/polariton trapped systems

The entanglement evolution of interacting trapped solid-state bosons, i.e. excitons or polaritons, is theoretically studied. From an initially separable state the quasi-particle interactions generate boson entanglement which is degraded as dissipation takes place. Based on exact solutions of a Markovian Master equation at T = 0 K, we discuss how dissipation affects the quantum entanglement dynamics of coupled solid-state boson systems. The single trap Wigner function is also calculated and its relationship to the trapped boson entanglement is discussed.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2011

STUDY OF FOUR YOUNG TeV PULSAR WIND NEBULAE WITH A SPECTRAL EVOLUTION MODEL

We study four young pulsar wind nebulae (PWNe) detected in TeV {gamma}-rays, G21.5-0.9, G54.1+0.3, Kes 75, and G0.9+0.1, using the spectral evolution model developed and applied to the Crab Nebula in our previous work. We model the evolution of the magnetic field and the particle distribution function inside a uniformly expanding PWN considering a time-dependent injection from the pulsar and radiative and adiabatic losses. Considering uncertainties in the interstellar radiation field (ISRF) and their distance, we study two cases for each PWN. Because TeV PWNe have a large TeV {gamma}-ray to X-ray flux ratio, the magnetic energy of the PWNe accounts for only a small fraction of the total energy injected (typically a few Multiplication-Sign 10{sup -3}). The {gamma}-ray emission is dominated by inverse Compton scattering off the infrared photons of the ISRF. A broken power-law distribution function for the injected particles reproduces the observed spectrum well, except for G0.9+0.1. For G0.9+0.1, we do not need a low-energy counterpart because adiabatic losses alone are enough to reproduce the radio observations. High-energy power-law indices at injection are similar (2.5-2.6), while low-energy power-law indices range from 1.0 to 1.6. The lower limit of the particle injection rate indicates that the pair multiplicity is larger than 10{sup 4}. The corresponding upper limit of the bulk Lorentz factor of the pulsar winds is close to the break energy of the broken power-law injection, except for Kes 75. The initial rotational energy and the magnetic energy of the pulsars seem anticorrelated, although the statistics are poor.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2011

India-based Neutrino Observatory(INO): A Status Report

We present a status report on the proposed India-based Neutrino Observatory (INO). Various aspects of the INO project such as its location, the present status of the detector development, physics goals and simulation studies are discussed briefly. In particular we focus on physics studies possible with an iron calorimeter detector (ICAL) and the logistics of constructing this detector at INO. Such a detector would make precision measurements of neutrino oscillation parameters with atmospheric neutrinos in the first phase with the possibility of acting as a far-end detector of a future neutrino factory or beta beam.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2011

Measuring the NuMI Beam Flux for MINERvA

MINERvA is employing multiple tools to understand its neutrino beam flux. We utilize external hadron production data, but we also depend heavily on in situ techniques in which we reduce our hadron production uncertainties by tuning our Monte Carlo to both MINERvA detector data and muon monitor data.

43 PARTICLE ACCELERATORS↗
DOE OSTI2011

Neutrinoless double beta decay and nuclear matrix elements

The fundamental importance of searching for neutrinoless double-beta decay (0{nu}{beta}{beta}-decay) is widely recognized. Observation of the decay would tell us that the total lepton number is not conserved and that, consequently, neutrinos are massive Majorana fermions. The 0{nu}{beta}{beta}-decay is discussed in context of neutrino oscillation data. The perspectives of the experimental 0{nu}{beta}{beta}-decay searches are analyzed. The importance of reliable determination of the 0{nu}{beta}{beta}-decay nuclear matrix elements is pointed out.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2011

Status of 3+1 neutrino mixing

We present an update of our analysis of short-baseline neutrino oscillation data in the framework of 3+1 neutrino mixing taking into account the recent update of MiniBooNE antineutrino data and the recent results of the MINOS search for {nu}{sub {mu}} disappearance into sterile neutrinos (the more complicated 3+2 neutrino mixing is not needed since the CP-violating difference between MiniBooNE neutrino and antineutrino data has diminished). The results of our fits of short-baseline neutrino oscillation data including the MiniBooNE low-energy anomaly (now present both in the neutrino and antineutrino data) lead to a strong tension between appearance and disappearance data. Hence, it seems likely that the low-energy anomaly is not due to transitions. Excluding the MiniBooNE low-energy anomaly, appearance and disappearance data are marginally compatible. The global analysis has the best-fit point at {Delta}m{sub 41}{sup 2}{approx_equal}5.6 eV{sup 2}, which is rather large in comparison with cosmological bounds, but there are three regions within 1{sigma} at {Delta}m{sub 41}{sup 2}{approx_equal}1.6, 1.2, 0.91 eV{sup 2}. We also show that the data on the Gallium neutrino anomaly favor values of {Delta}m{sub 41}{sup 2} larger than about 1 eV{sup 2}.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2011

g{sub VS}{gamma} coupling constant in light cone QCD

We recalculated the coupling constants g{sub {phi}{sigma}{gamma}}, g{sub {phi}a{sub 0}{gamma}}, g{sub {omega}{sigma}{gamma}}, g{sub a{sub 0}{omega}{gamma}}, g{sub {rho}{sigma}{gamma}}, and g{sub a{sub 0}{rho}{gamma}} by taking into account the contributions of the three-particle up to twist-4 distribution amplitudes of the photon involving quark-gluon and quark-anti-quark-photon fields in the light-cone sum-rule framework.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2011

Asymmetric Neutrino Reactions from Magnetized Proto-Neutron Stars in fully Relativistic Framework including Hyperons

We calculate the neutrino scattering and absorption on the hot and dense neutron-star matter with hyperons under the strong magnetic field using perturbative approach. We find that the absorption cross-sections show the remarkable angular dependence: its strength is reduced in the direction parallel to the magnetic field and enhanced in the opposite direction. This variation becomes about 2.2% when the magnetic field is about 2x10{sup 17} G.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2011

Near Detectors for a Neutrino Factory

The baseline design for a Neutrino Factory includes the need for one or more near detectors.The near detectors must be designed to carry out measurements essential to the sensitivity of the oscillation-physics program. In addition, the intense neutrino beam delivered by the Neutrino Factory makes it possible to carry out a unique neutrino-physics program at the near detectors. This program includes fundamental electroweak and QCD physics. The near detector must also be capable of searching for new physics, for example by detecting tau-leptons which are particularly sensitive probes of non-standard interactions at source and at detection. This paper is extracted from the Near Detector chapter of the Neutrino Factory Interim Design Report.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2011

Different Contributions of the {phi}{yields}K{sup 0}K-bar{sup 0}{gamma} Decay

The scalar mesons and vector mesons contribution to the radiative decay {phi}{yields}K{sup 0}K-bar{sup 0}{gamma} are studied within the framework of the phenomenological approach. The branching ratio of this decay is calculated to be 10{sup -8}-10{sup -12}. Furthermore, obtained values are compared with the experimental and theoretical results existing in the literature.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2011

THE FERMI GAMMA-RAY HAZE FROM DARK MATTER ANNIHILATIONS AND ANISOTROPIC DIFFUSION

Recent full-sky maps of the Galaxy from the Fermi Gamma-Ray Space Telescope have revealed a diffuse component of emission toward the Galactic center and extending up to roughly {+-}50{sup 0} in latitude. This Fermi 'haze' is the inverse Compton emission generated by the same electrons that generate the microwave synchrotron haze at Wilkinson Microwave Anisotropy Probe wavelengths. The gamma-ray haze has two distinct characteristics: the spectrum is significantly harder than emission elsewhere in the Galaxy and the morphology is elongated in latitude with respect to longitude with an axis ratio of {approx}2. If these electrons are generated through annihilations of dark matter (DM) particles in the Galactic halo, this morphology is difficult to realize with a standard spherical halo and isotropic cosmic-ray (CR) diffusion. However, we show that anisotropic diffusion along ordered magnetic field lines toward the center of the Galaxy coupled with a prolate DM halo can easily yield the required morphology without making unrealistic assumptions about diffusion parameters. Furthermore, a Sommerfeld enhancement to the self-annihilation cross-section of {approx}30 yields a good fit to the morphology, amplitude, and spectrum of both the gamma-ray and microwave haze. The model is also consistent with local CR measurements as well as cosmic microwave background constraints.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2011

Entanglement of Quasielastic Scattering and Pion Production

The extraction of neutrino oscillation parameters requires the determination of the neutrino energy from observations of the hadronic final state. Here we discuss the difficulties connected with this energy reconstruction for the ongoing experiments MiniBooNE and T2K. We point out that a lower limit to the uncertainty in the reconstructed energy from Fermi motion alone amounts to about 15%. The entanglement of very different elementary processes, in this case quasielastic scattering and pion production, in the actual observables leads to considerably larger errors. We discuss the sensitivity of the energy reconstruction to detection techniques and experimental acceptances. We also calculate the misidentification cross section for electron appearance in the T2K experiment due to neutral pion production.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2011

Faraday effect in ZnO:Mn thin films

Undoped and Mn-doped ZnO transparent thin films were grown by RF magnetron co-sputtering. The films are nanocrystalline, with wurtzite-structure grains of a typical size of 20 nm, with a preferential orientation of the c-axis perpendicular to the surface. Although, according to the Raman spectroscopy data, Mn mostly substitutes Zn in the lattice sites, factor that is considered favorable for ferromagnetism in this material, the ZnO:Mn films are paramagnetic at room temperature as it follows from our Faraday effect (FE) measurements. The FE spectra show a significant influence of the Mn ions for photon energies sufficiently below the ZnO:Mn band gap but not in its vicinity.

36 MATERIALS SCIENCE↗