Mechanism and computational model for Lyman-α-radiation generation by high-intensity-laser four-wave mixing in Kr-Ar gas

NASA Astrophysics Data System (ADS)

Louchev, Oleg A.; Bakule, Pavel; Saito, Norihito; Wada, Satoshi; Yokoyama, Koji; Ishida, Katsuhiko; Iwasaki, Masahiko

2011-09-01

We present a theoretical model combined with a computational study of a laser four-wave mixing process under optical discharge in which the non-steady-state four-wave amplitude equations are integrated with the kinetic equations of initial optical discharge and electron avalanche ionization in Kr-Ar gas. The model is validated by earlier experimental data showing strong inhibition of the generation of pulsed, tunable Lyman-α (Ly-α) radiation when using sum-difference frequency mixing of 212.6 nm and tunable infrared radiation (820-850 nm). The rigorous computational approach to the problem reveals the possibility and mechanism of strong auto-oscillations in sum-difference resonant Ly-α generation due to the combined effect of (i) 212.6-nm (2+1)-photon ionization producing initial electrons, followed by (ii) the electron avalanche dominated by 843-nm radiation, and (iii) the final breakdown of the phase matching condition. The model shows that the final efficiency of Ly-α radiation generation can achieve a value of ˜5×10-4 which is restricted by the total combined absorption of the fundamental and generated radiation.

Probing leptophilic dark sectors with hadronic processes

NASA Astrophysics Data System (ADS)

D'Eramo, Francesco; Kavanagh, Bradley J.; Panci, Paolo

2017-08-01

We study vector portal dark matter models where the mediator couples only to leptons. In spite of the lack of tree-level couplings to colored states, radiative effects generate interactions with quark fields that could give rise to a signal in current and future experiments. We identify such experimental signatures: scattering of nuclei in dark matter direct detection; resonant production of lepton-antilepton pairs at the Large Hadron Collider; and hadronic final states in dark matter indirect searches. Furthermore, radiative effects also generate an irreducible mass mixing between the vector mediator and the Z boson, severely bounded by ElectroWeak Precision Tests. We use current experimental results to put bounds on this class of models, accounting for both radiatively induced and tree-level processes. Remarkably, the former often overwhelm the latter.

Probing leptophilic dark sectors with hadronic processes

DOE PAGES

D'Eramo, Francesco; Kavanagh, Bradley J.; Panci, Paolo

2017-05-29

We study vector portal dark matter models where the mediator couples only to leptons. In spite of the lack of tree-level couplings to colored states, radiative effects generate interactions with quark fields that could give rise to a signal in current and future experiments. We identify such experimental signatures: scattering of nuclei in dark matter direct detection; resonant production of lepton–antilepton pairs at the Large Hadron Collider; and hadronic final states in dark matter indirect searches. Furthermore, radiative effects also generate an irreducible mass mixing between the vector mediator and the Z boson, severely bounded by ElectroWeak Precision Tests. Wemore » use current experimental results to put bounds on this class of models, accounting for both radiatively induced and tree-level processes. Remarkably, the former often overwhelm the latter.« less

Final Report for Annex II--Assessment of Solar Radiation Resources In Saudi Arabia, 1998-2000

DOE Office of Scientific and Technical Information (OSTI.GOV)

Myers, D. R.; Wilcox, S. M.; Marion, W. F.

2002-04-01

The Final Report for Annex II - Assessment of Solar Radiation Resources in Saudi Arabia 1998-2000 summarizes the accomplishment of work performed, results achieved, and products produced under Annex II, a project established under the Agreement for Cooperation in the Field of Renewable Energy Research and Development between the Kingdom of Saudi Arabia and the United States. The report covers work and accomplishments from January 1998 to December 2000. A previous progress report, Progress Report for Annex II - Assessment of Solar Radiation Resources in Saudi Arabia 1993-1997, NREL/TP-560-29374, summarizes earlier work and technical transfer of information under the project.more » The work was performed in at the National Renewable Energy Laboratory (NREL) in Golden, Colorado, at the King Abdulaziz City for Science and Technology (KACST) in Riyadh, Saudi Arabia, and at selected weather stations of the Saudi Meteorological and Environmental Protection Administration (MEPA).« less

United States Air Force Summer Research Program -- 1993 Summer Research Program Final Reports. Volume 12. Armstrong Laboratory

DTIC Science & Technology

1993-01-01

Panasonic TLD . Panasonic Industrial Company; Secaucus, New Jersey. 5. Thurlow, Ronald M. "Neutron Dosimetry Using a Panasonic Thermoluminescent Dosimeter." A...steps 8-12. 29-15 THE BUILDING OF THE USAF PANASONIC UD-809AS ALGORITHM Katherine M. Arnold Research Associate Radiation Dosimetry Branch Brooks Air...Research August 1993 30-1 THE BUILDING OF THE USAF PANASONIC UD-809AS ALGORITHM Katherine M. Arnold Research Associate Radiation Dosimetry Branch

Modeling circumbinary planets: The case of Kepler-38

NASA Astrophysics Data System (ADS)

Kley, Wilhelm; Haghighipour, Nader

2014-04-01

Context. Recently, a number of planets orbiting binary stars have been discovered by the Kepler space telescope. In a few systems the planets reside close to the dynamical stability limit. Owing to the difficulty of forming planets in such close orbits, it is believed that they have formed farther out in the disk and migrated to their present locations. Aims: Our goal is to construct more realistic models of planet migration in circumbinary disks and to determine the final position of these planets more accurately. In our work, we focus on the system Kepler-38 where the planet is close to the stability limit. Methods: The evolution of the circumbinary disk is studied using two-dimensional hydrodynamical simulations. We study locally isothermal disks as well as more realistic models that include full viscous heating, radiative cooling from the disk surfaces, and radiative diffusion in the disk midplane. After the disk has been brought into a quasi-equilibrium state, a 115 Earth-mass planet is embedded and its evolution is followed. Results: In all cases the planets stop inward migration near the inner edge of the disk. In isothermal disks with a typical disk scale height of H/r = 0.05, the final outcome agrees very well with the observed location of planet Kepler-38b. For the radiative models, the disk thickness and location of the inner edge is determined by the mass in the system. For surface densities on the order of 3000 g/cm2 at 1 AU, the inner gap lies close to the binary and planets stop in the region between the 5:1 and 4:1 mean-motion resonances with the binary. A model with a disk with approximately a quarter of the mass yields a final position very close to the observed one. Conclusions: For planets migrating in circumbinary disks, the final position is dictated by the structure of the disk. Knowing the observed orbits of circumbinary planets, radiative disk simulations with embedded planets can provide important information on the physical state of the system during the final stages of its evolution. Movies are available in electronic form at http://www.aanda.org

Observation of χ cJ decaying into the pp̄K⁺K⁻ final state

DOE PAGES

Ablikim, M.; Achasov, M. N.; Alberto, D.; ...

2011-06-27

First measurements of the decays of the three χ cJ states to pp̄K⁺K⁻ final states are presented. Intermediate Φ→K⁺K⁻ and Λ(1520)→pK⁻ resonance states are observed, and branching fractions for χ cJ→p̄K⁺Λ(1520), Λ(1520)Λ¯¯¯(1520), and Φpp̄ are reported. We also measure branching fractions for direct χ cJ→pp̄K⁺K⁻ decays. These are first observations of χ cJ decays to unstable baryon resonances and provide useful information about the χ cJ states. The experiment uses samples of χ cJ mesons produced via radiative transitions from 106×10⁶ ψ' mesons collected in the BESIII detector at the BEPCII e⁺e⁻ collider.

Interference between two resonant transitions with distinct initial and final states connected by radiative decay

NASA Astrophysics Data System (ADS)

Marsman, A.; Horbatsch, M.; Hessels, E. A.

2017-12-01

The resonant line shape from driving a transition between two states, |a 〉 and |b 〉 , can be distorted due to a quantum-mechanical interference effect involving a resonance between two different states, |c 〉 and |d 〉 , if |c 〉 has a decay path to |a 〉 and |d 〉 has a decay path to |b 〉 . This interference can cause a shift of the measured resonance, despite the fact that the two resonances do not have a common initial or final state. As an example, we demonstrate that such a shift affects measurements of the atomic hydrogen 2 S1 /2 -to-2 P1 /2 Lamb-shift transition due to 3 S -to-3 P transitions if the 3 S1 /2 state has some initial population.

Calibration of GOES-derived solar radiation data using a distributed network of surface measurements in Florida, USA

USGS Publications Warehouse

Sumner, David M.; Pathak, Chandra S.; Mecikalski, John R.; Paech, Simon J.; Wu, Qinglong; Sangoyomi, Taiye; Babcock, Roger W.; Walton, Raymond

2008-01-01

Solar radiation data are critically important for the estimation of evapotranspiration. Analysis of visible-channel data derived from Geostationary Operational Environmental Satellites (GOES) using radiative transfer modeling has been used to produce spatially- and temporally-distributed datasets of solar radiation. An extensive network of (pyranometer) surface measurements of solar radiation in the State of Florida has allowed refined calibration of a GOES-derived daily integrated radiation data product. This refinement of radiation data allowed for corrections of satellite sensor drift, satellite generational change, and consideration of the highly-variable cloudy conditions that are typical of Florida. To aid in calibration of a GOES-derived radiation product, solar radiation data for the period 1995–2004 from 58 field stations that are located throughout the State were compiled. The GOES radiation product was calibrated by way of a three-step process: 1) comparison with ground-based pyranometer measurements on clear reference days, 2) correcting for a bias related to cloud cover, and 3) deriving month-by-month bias correction factors. Pre-calibration results indicated good model performance, with a station-averaged model error of 2.2 MJ m–2 day–1 (13 percent). Calibration reduced errors to 1.7 MJ m–2 day–1 (10 percent) and also removed time- and cloudiness-related biases. The final dataset has been used to produce Statewide evapotranspiration estimates.

Application of linear multifrequency-grey acceleration to preconditioned Krylov iterations for thermal radiation transport

DOE PAGES

Till, Andrew T.; Warsa, James S.; Morel, Jim E.

2018-06-15

The thermal radiative transfer (TRT) equations comprise a radiation equation coupled to the material internal energy equation. Linearization of these equations produces effective, thermally-redistributed scattering through absorption-reemission. In this paper, we investigate the effectiveness and efficiency of Linear-Multi-Frequency-Grey (LMFG) acceleration that has been reformulated for use as a preconditioner to Krylov iterative solution methods. We introduce two general frameworks, the scalar flux formulation (SFF) and the absorption rate formulation (ARF), and investigate their iterative properties in the absence and presence of true scattering. SFF has a group-dependent state size but may be formulated without inner iterations in the presence ofmore » scattering, while ARF has a group-independent state size but requires inner iterations when scattering is present. We compare and evaluate the computational cost and efficiency of LMFG applied to these two formulations using a direct solver for the preconditioners. Finally, this work is novel because the use of LMFG for the radiation transport equation, in conjunction with Krylov methods, involves special considerations not required for radiation diffusion.« less

Potential development of an intercity passenger transit system in Texas : final project report.

DOT National Transportation Integrated Search

2010-05-01

This report describes the findings of a research study of the potential for development of an intercity rail and : express bus system in the state of Texas. Rather than focus on regional commuter or light rail systems : radiating from urban areas, th...

Radiation fluxes at the FIFE site. Final report, 1 January 1991-31 July 1992

DOE Office of Scientific and Technical Information (OSTI.GOV)

Walter-Shea, E.A.; Blad, B.L.; Zara, P.

1993-01-01

The main objective of the International Satellite Land Surface Climatology Project (ISLSCP) has been stated as 'the development of techniques that may be applied to satellite observations of the radiation reflected and emitted from the Earth to yield quantitative information concerning land surface climatological conditions'. The major field study, FIFE (the First ISLSCP Field Experiment), was conducted in 1987-89 to accomplish this objective. Four intensive field campaigns (IFC's) were carried out in 1987 and one in 1989. Factors contributing to observed reflected radiation from the FIFE site must be understood before the radiation observed by satellites can be used tomore » quantify surface processes. Our last report (Walter-Shea et al.) focused on slope effects on incoming and outgoing shortwave radiation and net radiation from data collected in 1989. We report here on the final analysis of the slope data as well as results from thermal radiation studies conducted during the FIFE experiment. The specific areas reported are the following: (1) analysis of slope effects on measured reflectance values and estimates of surface albedo; (2) using remotely-measured surface temperatures as a means of estimating sensible heat flux from the Konza Prairie; (3) extracting canopy temperatures from remotely-measured composite surface temperatures; (4) modeling the measured composite temperature of partially vegetated surfaces; and (5) estimating gap distribution in partially vegetated surfaces from reflectance measurements.« less

Cross sections for the reactions e + e - → K S 0 K L 0 π 0 , K S 0 K L 0 η , and K S 0 K L 0 π 0 π 0 from events with initial-state radiation

DOE PAGES

Lees, J. P.; Poireau, V.; Tisserand, V.; ...

2017-03-06

Here, we study the processes e + e - → Kmore » $$0\\atop{S}$$ K$$0\\atop{L}$$ π 0 γ , K $$0\\atop{S}$$ K$$0\\atop{L}$$ η γ , and K$$0\\atop{S}$$ K$$0\\atop{L}$$ π 0 π 0 γ , where the photon is radiated from the initial state, providing cross section measurements for the hadronic final states over a continuum of center-of-mass energies. The results are based on 469 fb -1 of data collected at or near the Υ ( 4 S ) resonance with the BABAR detector at SLAC. We present the first measurements of the e + e - → K$$0\\atop{S}$$ K$$0\\atop{L}$$ π 0 , K$$0\\atop{S}$$ K$$0\\atop{L}$$ η , and K$$0\\atop{S}$$ K$$0\\atop{L}$$ π 0π 0 cross sections up to a center-of-mass energy of 4 GeV and study their intermediate resonance structures. We observe J / ψ decays to all of these final states for the first time, present measurements of their J / ψ branching fractions, and search for ψ (2S) decays.« less

Cross sections for the reactions e + e - → K S 0 K L 0 π 0 , K S 0 K L 0 η , and K S 0 K L 0 π 0 π 0 from events with initial-state radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lees, J. P.; Poireau, V.; Tisserand, V.

Here, we study the processes e + e - → Kmore » $$0\\atop{S}$$ K$$0\\atop{L}$$ π 0 γ , K $$0\\atop{S}$$ K$$0\\atop{L}$$ η γ , and K$$0\\atop{S}$$ K$$0\\atop{L}$$ π 0 π 0 γ , where the photon is radiated from the initial state, providing cross section measurements for the hadronic final states over a continuum of center-of-mass energies. The results are based on 469 fb -1 of data collected at or near the Υ ( 4 S ) resonance with the BABAR detector at SLAC. We present the first measurements of the e + e - → K$$0\\atop{S}$$ K$$0\\atop{L}$$ π 0 , K$$0\\atop{S}$$ K$$0\\atop{L}$$ η , and K$$0\\atop{S}$$ K$$0\\atop{L}$$ π 0π 0 cross sections up to a center-of-mass energy of 4 GeV and study their intermediate resonance structures. We observe J / ψ decays to all of these final states for the first time, present measurements of their J / ψ branching fractions, and search for ψ (2S) decays.« less

Fundamentals of metasurface lasers based on resonant dark states

DOE PAGES

Droulias, Sotiris; Jain, Aditya; Koschny, Thomas; ...

2017-10-30

Recently, our group proposed a metamaterial laser design based on explicitly coupled dark resonant states in low-loss dielectrics, which conceptually separates the gain-coupled resonant photonic state responsible for macroscopic stimulated emission from the coupling to specific free-space propagating modes, allowing independent adjustment of the lasing state and its coherent radiation output. Due to this functionality, it is now possible to make lasers that can overcome the trade-off between system dimensions and Q factor, especially for surface emitting lasers with deeply subwavelength thickness. In this paper, we give a detailed discussion of the key functionality and benefits of this design, suchmore » as radiation damping tunability, directionality, subwavelength integration, and simple layer-by-layer fabrication. Finally, we examine in detail the fundamental design tradeoffs that establish the principle of operation and must be taken into account and give guidance for realistic implementations.« less

Sparticles in motion: Analyzing compressed SUSY scenarios with a new method of event reconstruction

NASA Astrophysics Data System (ADS)

Jackson, Paul; Rogan, Christopher; Santoni, Marco

2017-02-01

The observation of light superpartners from a supersymmetric extension to the Standard Model is an intensely sought-after experimental outcome, providing an explanation for the stabilization of the electroweak scale and indicating the existence of new particles which could be consistent with dark matter phenomenology. For compressed scenarios, where sparticle spectra mass splittings are small and decay products carry low momenta, dedicated techniques are required in all searches for supersymmetry. In this paper we suggest an approach for these analyses based on the concept of recursive jigsaw reconstruction, decomposing each event into a basis of complementary observables, for cases where strong initial state radiation has sufficient transverse momentum to elicit the recoil of any final state sparticles. We introduce a collection of kinematic observables which can be used to probe compressed scenarios, in particular exploiting the correlation between missing momentum and that of radiative jets. As an example, we study squark and gluino production, focusing on mass-splittings between parent superparticles and their lightest decay products between 25 and 200 GeV, in hadronic final states where there is an ambiguity in the provenance of reconstructed jets.

Calculation of State Specific Rate Coefficients for Non-Equilibrium Hypersonics Applications: from H(Psi) = E(Psi) to k(T) = A *exp(-E(sub a)/RT)

NASA Technical Reports Server (NTRS)

Jaffe, Richard; Schwenke, David; Chaban, Galina; Panesi, Marco

2014-01-01

Development of High-Fidelity Physics-Based Models to describe hypersonic flight through the atmospheres of Earth and Mars is underway at NASA Ames Research Center. The goal is to construct chemistry models of the collisional and radiative processes that occur in the bow shock and boundary layers of spacecraft during atmospheric entry that are free of empiricism. In this talk I will discuss our philosophy and describe some of our progress. Topics to be covered include thermochemistry, internal energy relaxation, collisional dissociation and radiative emission and absorption. For this work we start by solving the Schrodinger equation to obtain accurate interaction potentials and radiative properties. Then we invoke classical mechanics to compute state-specific heavy particle collision cross sections and reaction rate coefficients. Finally, phenomenological rate coefficients and relaxation times are determined from master equation solutions.

Identification of a Core Curriculum in Gerontology for Allied Health Professionals. Final Report.

ERIC Educational Resources Information Center

Hedl, John J.; And Others

The overall goal of this project was to identify a core curriculum in gerontology for seven allied health professions (radiologic technologist, radiation therapist, respiratory therapist, dental hygienist, dental assistant, physical therapy assistant, and occupational therapy assistant). The project also identified the current state of gerontology…

High pressure and synchrotron radiation studies of solid state electronic instabilities. Final technial report, May 1, 1984--April 1987

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pifer, J.H.; Croft, M.C.

This report discusses Eu and General Valence Instabilities; Ce Problem: L{sub 3} Spectroscopy Emphasis; Bulk Property Emphasis; Transition Metal Compound Electronic Structure; Electronic Structure-Phonon Coupling Studies; High Temperature Superconductivity and Oxide Materials; and Novel Materials Collaboration with Chemistry.

A STUDY OF THE AEROSOL RADIATIVE PROPERTIES NEEDED TO COMPUTE DIRECT AEROSOL FORCING IN THE SOUTHEASTERN UNITED STATES. (R825248)

EPA Science Inventory

The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

Select strengths and biases of models in representing the Arctic winter boundary layer over sea ice: the Larcform 1 single column model intercomparison

DOE PAGES

Pithan, Felix; Ackerman, Andrew; Angevine, Wayne M.; ...

2016-08-27

We struggle to represent lower tropospheric temperature and moisture profiles and surface fluxes in Artic winter using weather and climate models, partly because they lack or misrepresent physical processes that are specific to high latitudes. Observations have revealed two preferred states of the Arctic winter boundary layer. In the cloudy state, cloud liquid water limits surface radiative cooling, and temperature inversions are weak and elevated. In the radiatively clear state, strong surface radiative cooling leads to the build-up of surface-based temperature inversions. Many large-scale models lack the cloudy state, and some substantially underestimate inversion strength in the clear state. Themore » transformation from a moist to a cold dry air mass is modeled using an idealized Lagrangian perspective. The trajectory includes both boundary layer states, and the single-column experiment is the first Lagrangian Arctic air formation experiment (Larcform 1) organized within GEWEX GASS (Global atmospheric system studies). The intercomparison reproduces the typical biases of large-scale models: some models lack the cloudy state of the boundary layer due to the representation of mixed-phase microphysics or to the interaction between micro- and macrophysics. In some models, high emissivities of ice clouds or the lack of an insulating snow layer prevent the build-up of surface-based inversions in the radiatively clear state. Models substantially disagree on the amount of cloud liquid water in the cloudy state and on turbulent heat fluxes under clear skies. Finally, observations of air mass transformations including both boundary layer states would allow for a tighter constraint of model behavior.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Droulias, Sotiris; Jain, Aditya; Koschny, Thomas

Recently, our group proposed a metamaterial laser design based on explicitly coupled dark resonant states in low-loss dielectrics, which conceptually separates the gain-coupled resonant photonic state responsible for macroscopic stimulated emission from the coupling to specific free-space propagating modes, allowing independent adjustment of the lasing state and its coherent radiation output. Due to this functionality, it is now possible to make lasers that can overcome the trade-off between system dimensions and Q factor, especially for surface emitting lasers with deeply subwavelength thickness. In this paper, we give a detailed discussion of the key functionality and benefits of this design, suchmore » as radiation damping tunability, directionality, subwavelength integration, and simple layer-by-layer fabrication. Finally, we examine in detail the fundamental design tradeoffs that establish the principle of operation and must be taken into account and give guidance for realistic implementations.« less

Direct evidence for radiative charge transfer after inner-shell excitation and ionization of large clusters

NASA Astrophysics Data System (ADS)

Hans, Andreas; Stumpf, Vasili; Holzapfel, Xaver; Wiegandt, Florian; Schmidt, Philipp; Ozga, Christian; Reiß, Philipp; Ben Ltaief, Ltaief; Küstner-Wetekam, Catmarna; Jahnke, Till; Ehresmann, Arno; Demekhin, Philipp V.; Gokhberg, Kirill; Knie, André

2018-01-01

We directly observe radiative charge transfer (RCT) in Ne clusters by dispersed vacuum-ultraviolet photon detection. The doubly ionized Ne2+-{{{N}}{{e}}}n-1 initial states of RCT are populated after resonant 1s-3p photoexcitation or 1s photoionization of Ne n clusters with < n> ≈ 2800. These states relax further producing Ne+-Ne+-{{{N}}{{e}}}n-2 final states, and the RCT photon is emitted. Ab initio calculations assign the observed RCT signal to the{}{{{N}}{{e}}}2+(2{{{p}}}-2{[}1{{D}}]){--}{{{N}}{{e}}}n-1 initial state, while transitions from other possible initial states are proposed to be quenched by competing relaxation processes. The present results are in agreement with the commonly discussed scenario, where the doubly ionized atom in a noble gas cluster forms a dimer which dissipates its vibrational energy on a picosecond timescale. Our study complements the picture of the RCT process in weakly bound clusters, providing information which is inaccessible by charged particle detection techniques.

Measurement of initial-state–final-state radiation interference in the processes e + e – → μ + μ – γ and e + e – → π + π – γ [Measurement of ISR-FSR interference in the processes e + e – → μ + μ – γ and e + e – → π + π – γ

DOE PAGES

Lees, J. P.; Poireau, V.; Tisserand, V.; ...

2015-10-28

Charge asymmetry in the processes e +e – → μ +μ –γ and e +e – → π +π –γ is measured using 232 fb –1 of data collected with the BABAR detector at e +e – center-of-mass energies near 10.58 GeV. An observable is introduced and shown to be very robust against detector asymmetries while keeping a large sensitivity to the physical charge asymmetry that results from the interference between initial- and final-state radiation (FSR). The asymmetry is determined as a function of the invariant mass of the final-state tracks from production threshold to a few GeV/c 2. Itmore » is compared to the expectation from QED for e +e – → μ +μ –γ, and from theoretical models for e +e – → π +π –γ. A clear interference pattern is observed in e +e – → π +π –γ, particularly in the vicinity of the f 2(1270) resonance. As a result, the inferred rate of lowest-order FSR production is consistent with the QED expectation for e +e – → μ +μ –γ, and is negligibly small for e +e – → π +π –γ.« less

Measurement of initial-state–final-state radiation interference in the processes e + e – → μ + μ – γ and e + e – → π + π – γ [Measurement of ISR-FSR interference in the processes e + e – → μ + μ – γ and e + e – → π + π – γ

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lees, J. P.; Poireau, V.; Tisserand, V.

Charge asymmetry in the processes e +e – → μ +μ –γ and e +e – → π +π –γ is measured using 232 fb –1 of data collected with the BABAR detector at e +e – center-of-mass energies near 10.58 GeV. An observable is introduced and shown to be very robust against detector asymmetries while keeping a large sensitivity to the physical charge asymmetry that results from the interference between initial- and final-state radiation (FSR). The asymmetry is determined as a function of the invariant mass of the final-state tracks from production threshold to a few GeV/c 2. Itmore » is compared to the expectation from QED for e +e – → μ +μ –γ, and from theoretical models for e +e – → π +π –γ. A clear interference pattern is observed in e +e – → π +π –γ, particularly in the vicinity of the f 2(1270) resonance. As a result, the inferred rate of lowest-order FSR production is consistent with the QED expectation for e +e – → μ +μ –γ, and is negligibly small for e +e – → π +π –γ.« less

Study of final-state radiation in decays of Z bosons produced in $pp$ collisions at 7 TeV

DOE PAGES

Khachatryan, Vardan

2015-05-29

The differential cross sections for the production of photons in Z→μ +μ -γ decays are presented as a function of the transverse energy of the photon and its separation from the nearest muon. The data for these measurements are collected with the CMS detector and correspond to an integrated luminosity of 4.7 fb -1 of pp collisions at √s=7 TeV delivered by the CERN LHC. The cross sections are compared to simulations with powheg and pythia, where pythia is used to simulate parton showers and final-state photons. These simulations match the data to better than 5%.

X-Ray Laser Program Final Report for FY91

DTIC Science & Technology

1992-09-16

from a Na z pinch is used to photoionize Ne to the He-like ground state and radiation from the Na 1 s 2-1 s2p 1P1 transition is used to resonantly...creating photopumped x-ray lasers2 , imploding inertial confinement fusion capsules, 3 and studying the photoionization kinetics of plasmas in intense...has received extensive theoretical study, 5 -8 employs radiation from the 1s2 -1s2p 1P1 transition at 11.0027 A in He-like Na to resonantly photoexcite

Infrared spectroscopy of radiation-chemical transformation of n-hexane on a beryllium surface

NASA Astrophysics Data System (ADS)

Gadzhieva, N. N.

2017-07-01

The radiation-chemical decomposition of n-hexane in a Be- n-hexane system under the effect of γ-irradiation at room temperature is studied by infrared reflection-absorption spectroscopy. In the absorbed dose range 5 kGy ≤ Vγ ≤ 50 kGy, intermediate surface products of radiation-heterogeneous decomposition of n-hexane (beryllium alkyls, π-olefin complexes, and beryllium hydrides) are detected. It is shown that complete radiolysis occurs at Vγ = 30 kGy; below this dose, decomposition of n-hexane occurs only partially, while higher doses lead to steady-state saturation. The radiation-chemical yield of the final decomposition product—molecular hydrogen—is determined to be G ads(H2) = 24.8 molecules/100 eV. A possible mechanism of this process is discussed.

Measurement of the absolute branching ratio of the K+ →π+π-π+ (γ) decay with the KLOE detector

NASA Astrophysics Data System (ADS)

Babusci, D.; Balwierz-Pytko, I.; Bencivenni, G.; Bloise, C.; Bossi, F.; Branchini, P.; Budano, A.; Caldeira Balkeståhl, L.; Ceradini, F.; Ciambrone, P.; Curciarello, F.; Czerwiński, E.; Danè, E.; De Leo, V.; De Lucia, E.; De Robertis, G.; De Santis, A.; De Simone, P.; Di Cicco, A.; Di Domenico, A.; Di Salvo, R.; Domenici, D.; Erriquez, O.; Fanizzi, G.; Fantini, A.; Felici, G.; Fiore, S.; Franzini, P.; Gajos, A.; Gauzzi, P.; Giardina, G.; Giovannella, S.; Graziani, E.; Happacher, F.; Heijkenskjöld, L.; Höistad, B.; Johansson, T.; Kamińska, D.; Krzemien, W.; Kupsc, A.; Lee-Franzini, J.; Loddo, F.; Loffredo, S.; Mandaglio, G.; Martemianov, M.; Martini, M.; Mascolo, M.; Messi, R.; Miscetti, S.; Morello, G.; Moricciani, D.; Moskal, P.; Palladino, A.; Passeri, A.; Patera, V.; Prado Longhi, I.; Ranieri, A.; Santangelo, P.; Sarra, I.; Schioppa, M.; Sciascia, B.; Silarski, M.; Tortora, L.; Venanzoni, G.; Wiślicki, W.; Wolke, M.; KLOE/KLOE-2 Collaboration

2014-11-01

The absolute branching ratio of the K+ →π+π-π+ (γ) decay, inclusive of final-state radiation, has been measured using ∼17 million tagged K+ mesons collected with the KLOE detector at DAΦNE, the Frascati ϕ-factory. The result is:

Infrared problem in non-Abelian gauge theory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yao, Y.

1976-03-22

I extend the Bloch--Nordsieck idea to show that in the lowest nontrivial order of radiative correction the fermion--fermion and gauge-meson--fermion scattering rates are finite, provided that they are averaged over the initial and summed over the final internal spin states. Questions of the physical gauge coupling and infrared slavery are discussed. (AIP)

Extremal noncommutative black holes as dark matter furnaces

NASA Astrophysics Data System (ADS)

Kawamoto, Shoichi; Wei, Chun-Yu; Wen, Wen-Yu

2017-09-01

In this paper, we consider dark matter annihilation in the gravitational field of noncommutative black holes. Instead of a violent fate predicted in the usual Hawking radiation, we propose a thermal equilibrium state where a mildly burning black hole relic is fueled by dark matter accretion at the final stage of evaporation.

Gamma-ray Signal from Dark Matter Annihilation Mediated by Mixing Slepton

NASA Astrophysics Data System (ADS)

Teng, Fei

2016-03-01

In order to reconcile the tension between the collider SUSY particle search and the dark matter relic density constraint, we free ourselves from the simplest CMSSM model and find a large parameter space in which a sub-TeV bino dark matter may comply with all the current experimental constraints. In this so-called incredible bulk region, dark matter mainly annihilates through the t channel exchange of a mixing slepton into a leptonic final state. We have explored this proposal and studied the resultant spectrum feature. We are going to show that the line signal produced by the γγ and γZ final state will give some indications to the mixing angle and CP-violation phase of the slepton sector. On the other hand, internal bremsstrahlung (IB) feature will be easier to get observed by future experiments, with sensitivity around 10-29cm3 /s . Unlike some other models, our IB signal is dominated by the collinear limit of the final state radiation amplitude and shows a bump-like feature.

Study on radiation production in the charge stripping section of the RISP linear accelerator

NASA Astrophysics Data System (ADS)

Oh, Joo-Hee; Oranj, Leila Mokhtari; Lee, Hee-Seock; Ko, Seung-Kook

2015-02-01

The linear accelerator of the Rare Isotope Science Project (RISP) accelerates 200 MeV/nucleon 238U ions in a multi-charge states. Many kinds of radiations are generated while the primary beam is transported along the beam line. The stripping process using thin carbon foil leads to complicated radiation environments at the 90-degree bending section. The charge distribution of 238U ions after the carbon charge stripper was calculated by using the LISE++ program. The estimates of the radiation environments were carried out by using the well-proved Monte Carlo codes PHITS and FLUKA. The tracks of 238U ions in various charge states were identified using the magnetic field subroutine of the PHITS code. The dose distribution caused by U beam losses for those tracks was obtained over the accelerator tunnel. A modified calculation was applied for tracking the multi-charged U beams because the fundamental idea of PHITS and FLUKA was to transport fully-ionized ion beam. In this study, the beam loss pattern after a stripping section was observed, and the radiation production by heavy ions was studied. Finally, the performance of the PHITS and the FLUKA codes was validated for estimating the radiation production at the stripping section by applying a modified method.

On the performance of infrared sensors in earth observations

NASA Technical Reports Server (NTRS)

Johnson, L. F.

1972-01-01

The performance of infrared sensing systems is dependent upon the radiative properties of targets in addition to constraints imposed by system components. The unclassified state-of-the-art of infrared system performance figures is reviewed to indicate the relevance to system performance of target radiative properties. A theory of rough surface scattering is developed which allows the formulation of the reflective characteristics of extended targets. The thermal radiation emission from extended targets is formulated on the basis of internal radiation characteristics of natural materials and the transmissive scattering effects at the surface. Finally, the total radiative characteristics may be expressed as functions of material properties and incident and received directions, although the expressions are extremely complex functions and do not account for the effects of shadowing or multiple scattering. It is believed that the theory may be extended to include these effects and to incorporate the local radii of curvature of the surface.

A Commentary on: "A History of the United States Department of Energy (DOE) Low Dose Radiation Research Program: 1998-2008".

PubMed

Brooks, Antone L

2015-04-01

This commentary provides a very brief overview of the book "A History of the United States Department of Energy (DOE) Low Dose Radiation Research Program: 1998-2008" ( http://lowdose.energy.gov ). The book summarizes and evaluates the research progress, publications and impact of the U.S. Department of Energy Low Dose Radiation Research Program over its first 10 years. The purpose of this book was to summarize the impact of the program's research on the current thinking and low-dose paradigms associated with the radiation biology field and to help stimulate research on the potential adverse and/or protective health effects of low doses of ionizing radiation. In addition, this book provides a summary of the data generated in the low dose program and a scientific background for anyone interested in conducting future research on the effects of low-dose or low-dose-rate radiation exposure. This book's exhaustive list of publications coupled with discussions of major observations should provide a significant resource for future research in the low-dose and dose-rate region. However, because of space limitations, only a limited number of critical references are mentioned. Finally, this history book provides a list of major advancements that were accomplished by the program in the field of radiation biology, and these bulleted highlights can be found in last part of chapters 4-10.

Recoilless Nuclear Resonance Absorption of Gamma Radiation

NASA Astrophysics Data System (ADS)

Mössbauer, Rudolf L.

It is a high distinction to be permitted to address you on the subject of recoilless nuclear resonance absorption of gamma radiation. The methods used in this special branch of experimental physics have recently found acceptance in many areas of science. I take the liberty to confine myself essentially to the work which I was able to carry out in the years 1955-1958 at the Max Planck Institute in Heidelberg, and which finally led to establishment of the field of recoilless nuclear resonance absorption. Many investigators shared in the preparations of the basis for the research we are concerned with in this lecture. As early as the middle of the last century Stokes observed, in the case of fluorite, the phenomenon now known as fluorescence - namely, that solids, liquids, and gases under certain conditions partially absorb incident electromagnetic radiation which immediately is reradiated. A special case is the so-called resonance fluorescence, a phenomenon in which the re-emitted and the incident radiation both are of the same wavelength. The resonance fluorescence of the yellow D lines of sodium in sodium vapour is a particularly notable and exhaustively studied example. In this optical type of resonance fluorescence, light sources are used in which the atoms undergo transitions from excited states to their ground states (Fig. 1.1). The light quanta emitted in these transitions (A → B) are used to initiate the inverse process of resonance absorption in the atoms of an absorber which are identical with the radiating atoms. The atoms of the absorber undergo a transition here from the ground state (B) to the excited state (A), from which they again return to the ground state, after a certain time delay, by emission of fluorescent light.

Mode tuning of a simplified string instrument using time-dimensionless state-derivative control

NASA Astrophysics Data System (ADS)

Benacchio, Simon; Chomette, Baptiste; Mamou-Mani, Adrien; Finel, Victor

2015-01-01

In recent years, there has been a growing interest in smart structures, particularly in the field of musical acoustics. Control methods, initially developed to reduce vibration and damage, can be a good way to shift modal parameters of a structure in order to modify its dynamic response. This study focuses on smart musical instruments and aims to modify their radiated sound. This is achieved by controlling the modal parameters of the soundboard of a simplified string instrument. A method combining a pole placement algorithm and a time-dimensionless state-derivative control is used and quickly compared to a usual state control method. Then the effect of the mode tuning on the coupling between the string and the soundboard is experimentally studied. Controlling two vibration modes of the soundboard, its acoustic response and the damping of the third partial of the sound are modified. Finally these effects are listened in the radiated sound.

Inter- and intraconfigurational luminescence of Er3+ ions in BaY2F8 under VUV excitation

NASA Astrophysics Data System (ADS)

Kirm, M.; Lichtenberg, H.; Makhov, V. N.; Negodin, E.; Ouvarova, T. V.; Suljoti, E.; True, M.; Zimmerer, G.

Using energy- and time-resolved spectroscopy the luminescence properties of Er3+ doped BaY2F8 crystals were investigated at 10 K under VUV synchrotron radiation excitation. Radiative intraconfigurational f - f and interconfigurational d - f transitions in Er3+ ions were observed under f - d excitation. Whereas the onset of S-4(3/2) population via f - d excitation starts at 59 900 cm(-1) , efficient excitation of emissions arising from the P-2(3/2) state begins only above 67 000 cm(-1) in VUV region. Such behaviour can be explained by a cross-relaxation process of the type (F-2(2)(5/2) , I-4(15/2))-->(P-2(3/2) , P-2(3/2)) taking place within f -states of Er3+ ions finally populating the emitting P-2(3/2) state.

Advancements in Afterbody Radiative Heating Simulations for Earth Entry

NASA Technical Reports Server (NTRS)

Johnston, Christopher O.; Panesi, Marco; Brandis, Aaron M.

2016-01-01

Four advancements to the simulation of backshell radiative heating for Earth entry are presented. The first of these is the development of a flow field model that treats electronic levels of the dominant backshell radiator, N, as individual species. This is shown to allow improvements in the modeling of electron-ion recombination and two-temperature modeling, which are shown to increase backshell radiative heating by 10 to 40%. By computing the electronic state populations of N within the flow field solver, instead of through the quasi-steady state approximation in the radiation code, the coupling of radiative transition rates to the species continuity equations for the levels of N, including the impact of non-local absorption, becomes feasible. Implementation of this additional level of coupling between the flow field and radiation codes represents the second advancement presented in this work, which is shown to increase the backshell radiation by another 10 to 50%. The impact of radiative transition rates due to non-local absorption indicates the importance of accurate radiation transport in the relatively complex flow geometry of the backshell. This motivates the third advancement, which is the development of a ray-tracing radiation transport approach to compute the radiative transition rates and divergence of the radiative flux at every point for coupling to the flow field, therefore allowing the accuracy of the commonly applied tangent-slab approximation to be assessed for radiative source terms. For the sphere considered at lunar-return conditions, the tangent-slab approximation is shown to provide a sufficient level of accuracy for the radiative source terms, even for backshell cases. This is in contrast to the agreement between the two approaches for computing the radiative flux to the surface, which differ by up to 40%. The final advancement presented is the development of a nonequilibrium model for NO radiation, which provides significant backshell radiation at velocities below 10 km/s. The developed model reduces the nonequilibrium NO radiation by 50% relative to the previous model.

Final Technical Report for Year 5 Early Career Research Project "Viscosity and equation of state of hot and dense QCD matter"

DOE Office of Scientific and Technical Information (OSTI.GOV)

Molnar, Denes

2016-05-25

The Section below summarizes research activities and achievements during the fifth (last) year of the PI’s Early Career Research Project (ECRP). Unlike the first four years of the project, the last year was not funded under the American Recovery and Reinvestment Act (ARRA). The ECRP advanced two main areas: i) radiative 3 ↔ 2 radiative transport, via development of a new computer code MPC/Grid that solves the Boltzmann transport equation in full 6+1D (3X+3V+time); and ii) application of relativistic hydrodynamics, via development of a self-consistent framework to convert viscous fluids to particles. In Year 5 we finalized thermalization studies withmore » radiative gg ↔ ggg transport (Sec. 1.1.1) and used nonlinear covariant transport to assess the accuracy of fluid-to-particle conversion models (Sec. 1.1.2), calculated observables with self-consistent fluid-to-particle conversion from realistic viscous hydrodynamic evolution (Secs. 1.2.1 and 1.2.2), extended the covariant energy loss formulation to heavy quarks (Sec. 1.4.1) and studied energy loss in small systems (Sec. 1.4.2), and also investigated how much of the elliptic flow could have non-hydrodynamic origin (Sec 1.3). Years 1-4 of the ECRP were ARRA-funded and, therefore, they have their own report document ’Final Technical Report for Years 1-4 of the Early Career Research Project “Viscosity and equation of state of hot and dense QCD matter”’ (same award number DE-SC0004035). The PI’s group was also part of the DOE JET Topical Collaboration, a multi-institution project that overlapped in time significantly with the ECRP. Purdue achievements as part of the JET Top- ical Collaboration are in a separate report “Final Technical Report summarizing Purdue research activities as part of the DOE JET Topical Collaboration” (award DE-SC0004077).« less

76 FR 6692 - Radiation Sources on Army Land

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-08

...-AA58 Radiation Sources on Army Land AGENCY: Department of the Army, DoD. ACTION: Final rule. SUMMARY: The Department of the Army is finalizing revisions to its regulation concerning radiation sources on... Radiation Permit (ARP) from the garrison commander to use, store, or possess ionizing radiation sources on...

Management of radioactive material safety programs at medical facilities. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Camper, L.W.; Schlueter, J.; Woods, S.

A Task Force, comprising eight US Nuclear Regulatory Commission and two Agreement State program staff members, developed the guidance contained in this report. This report describes a systematic approach for effectively managing radiation safety programs at medical facilities. This is accomplished by defining and emphasizing the roles of an institution`s executive management, radiation safety committee, and radiation safety officer. Various aspects of program management are discussed and guidance is offered on selecting the radiation safety officer, determining adequate resources for the program, using such contractual services as consultants and service companies, conducting audits, and establishing the roles of authorized usersmore » and supervised individuals; NRC`s reporting and notification requirements are discussed, and a general description is given of how NRC`s licensing, inspection and enforcement programs work.« less

Solar radiation variability over La Réunion island and associated larger-scale dynamics

NASA Astrophysics Data System (ADS)

Mialhe, Pauline; Morel, Béatrice; Pohl, Benjamin; Bessafi, Miloud; Chabriat, Jean-Pierre

2017-04-01

This study aims to examine the solar radiation variability over La Réunion island and its relationship with large-scale circulation. The Satellite Application Facility on Climate Monitoring (CM SAF) produces a Shortwave Incoming Solar radiation (SIS) data record called Solar surfAce RAdiation Heliosat - East (SARAH-E). A comparison to in situ observations from Météo-France measurements networks quantifies the skill of SARAH-E grids which we use as dataset. First step of the work, irradiance mean cycles are calculated to describe the diurnal-seasonal SIS behaviour over La Réunion island. By analogy with the climate anomalies, instantaneous deviations are computed after removal of the mean states. Finally, we associate these anomalies with larger-scale atmospheric dynamics into the South West Indian Ocean by applying multivariate clustering analyses (Hierarchical Ascending Classification, k-means).

Cross sections for the reactions e+e-→K+K-π+π-, K+K-π0π0, and K+K-K+K- measured using initial-state radiation events

NASA Astrophysics Data System (ADS)

Lees, J. P.; Poireau, V.; Prencipe, E.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Martinelli, M.; Milanes, D. A.; Palano, A.; Pappagallo, M.; Eigen, G.; Stugu, B.; Sun, L.; Brown, D. N.; Kerth, L. T.; Kolomensky, Yu. G.; Lynch, G.; Koch, H.; Schroeder, T.; Asgeirsson, D. J.; Hearty, C.; Mattison, T. S.; McKenna, J. A.; Khan, A.; Blinov, V. E.; Buzykaev, A. R.; Druzhinin, V. P.; Golubev, V. B.; Kravchenko, E. A.; Onuchin, A. P.; Serednyakov, S. I.; Skovpen, Yu. I.; Solodov, E. P.; Todyshev, K. Yu.; Yushkov, A. N.; Bondioli, M.; Curry, S.; Kirkby, D.; Lankford, A. J.; Mandelkern, M.; Stoker, D. P.; Atmacan, H.; Gary, J. W.; Liu, F.; Long, O.; Vitug, G. M.; Campagnari, C.; Hong, T. M.; Kovalskyi, D.; Richman, J. D.; West, C. A.; Eisner, A. M.; Kroseberg, J.; Lockman, W. S.; Martinez, A. J.; Schalk, T.; Schumm, B. A.; Seiden, A.; Cheng, C. H.; Doll, D. A.; Echenard, B.; Flood, K. T.; Hitlin, D. G.; Ongmongkolkul, P.; Porter, F. C.; Rakitin, A. Y.; Andreassen, R.; Dubrovin, M. S.; Meadows, B. T.; Sokoloff, M. D.; Bloom, P. C.; Ford, W. T.; Gaz, A.; Nagel, M.; Nauenberg, U.; Smith, J. G.; Wagner, S. R.; Ayad, R.; Toki, W. H.; Spaan, B.; Kobel, M. J.; Schubert, K. R.; Schwierz, R.; Bernard, D.; Verderi, M.; Clark, P. J.; Playfer, S.; Watson, J. E.; Bettoni, D.; Bozzi, C.; Calabrese, R.; Cibinetto, G.; Fioravanti, E.; Garzia, I.; Luppi, E.; Munerato, M.; Negrini, M.; Piemontese, L.; Baldini-Ferroli, R.; Calcaterra, A.; de Sangro, R.; Finocchiaro, G.; Nicolaci, M.; Pacetti, S.; Patteri, P.; Peruzzi, I. M.; Piccolo, M.; Rama, M.; Zallo, A.; Contri, R.; Guido, E.; Lo Vetere, M.; Monge, M. R.; Passaggio, S.; Patrignani, C.; Robutti, E.; Bhuyan, B.; Prasad, V.; Lee, C. L.; Morii, M.; Edwards, A. J.; Adametz, A.; Marks, J.; Uwer, U.; Bernlochner, F. U.; Ebert, M.; Lacker, H. M.; Lueck, T.; Dauncey, P. D.; Tibbetts, M.; Behera, P. K.; Mallik, U.; Chen, C.; Cochran, J.; Crawley, H. B.; Meyer, W. T.; Prell, S.; Rosenberg, E. I.; Rubin, A. E.; Gritsan, A. V.; Guo, Z. J.; Arnaud, N.; Davier, M.; Derkach, D.; Grosdidier, G.; Le Diberder, F.; Lutz, A. M.; Malaescu, B.; Roudeau, P.; Schune, M. H.; Stocchi, A.; Wormser, G.; Lange, D. J.; Wright, D. M.; Bingham, I.; Chavez, C. A.; Coleman, J. P.; Fry, J. R.; Gabathuler, E.; Hutchcroft, D. E.; Payne, D. J.; Touramanis, C.; Bevan, A. J.; Di Lodovico, F.; Sacco, R.; Sigamani, M.; Cowan, G.; Paramesvaran, S.; Brown, D. N.; Davis, C. L.; Denig, A. G.; Fritsch, M.; Gradl, W.; Hafner, A.; Alwyn, K. E.; Bailey, D.; Barlow, R. J.; Jackson, G.; Lafferty, G. D.; Cenci, R.; Hamilton, B.; Jawahery, A.; Roberts, D. A.; Simi, G.; Dallapiccola, C.; Salvati, E.; Cowan, R.; Dujmic, D.; Sciolla, G.; Lindemann, D.; Patel, P. M.; Robertson, S. H.; Schram, M.; Biassoni, P.; Lazzaro, A.; Lombardo, V.; Palombo, F.; Stracka, S.; Cremaldi, L.; Godang, R.; Kroeger, R.; Sonnek, P.; Summers, D. J.; Nguyen, X.; Taras, P.; De Nardo, G.; Monorchio, D.; Onorato, G.; Sciacca, C.; Raven, G.; Snoek, H. L.; Jessop, C. P.; Knoepfel, K. J.; LoSecco, J. M.; Wang, W. F.; Honscheid, K.; Kass, R.; Brau, J.; Frey, R.; Sinev, N. B.; Strom, D.; Torrence, E.; Feltresi, E.; Gagliardi, N.; Margoni, M.; Morandin, M.; Posocco, M.; Rotondo, M.; Simonetto, F.; Stroili, R.; Ben-Haim, E.; Bomben, M.; Bonneaud, G. R.; Briand, H.; Calderini, G.; Chauveau, J.; Hamon, O.; Leruste, Ph.; Marchiori, G.; Ocariz, J.; Sitt, S.; Biasini, M.; Manoni, E.; Rossi, A.; Angelini, C.; Batignani, G.; Bettarini, S.; Carpinelli, M.; Casarosa, G.; Cervelli, A.; Forti, F.; Giorgi, M. A.; Lusiani, A.; Neri, N.; Oberhof, B.; Paoloni, E.; Perez, A.; Rizzo, G.; Walsh, J. J.; Lopes Pegna, D.; Lu, C.; Olsen, J.; Smith, A. J. S.; Telnov, A. V.; Anulli, F.; Cavoto, G.; Faccini, R.; Ferrarotto, F.; Ferroni, F.; Gaspero, M.; Li Gioi, L.; Mazzoni, M. A.; Piredda, G.; Bünger, C.; Hartmann, T.; Leddig, T.; Schröder, H.; Waldi, R.; Adye, T.; Olaiya, E. O.; Wilson, F. F.; Emery, S.; Hamel de Monchenault, G.; Vasseur, G.; Yèche, Ch.; Aston, D.; Bard, D. J.; Bartoldus, R.; Benitez, J. F.; Cartaro, C.; Convery, M. R.; Dorfan, J.; Dubois-Felsmann, G. P.; Dunwoodie, W.; Field, R. C.; Franco Sevilla, M.; Fulsom, B. G.; Gabareen, A. M.; Graham, M. T.; Grenier, P.; Hast, C.; Innes, W. R.; Kelsey, M. H.; Kim, H.; Kim, P.; Kocian, M. L.; Leith, D. W. G. S.; Lewis, P.; Li, S.; Lindquist, B.; Luitz, S.; Luth, V.; Lynch, H. L.; MacFarlane, D. B.; Muller, D. R.; Neal, H.; Nelson, S.; Ofte, I.; Perl, M.; Pulliam, T.; Ratcliff, B. N.; Roodman, A.; Salnikov, A. A.; Santoro, V.; Schindler, R. H.; Snyder, A.; Su, D.; Sullivan, M. K.; Va'vra, J.; Wagner, A. P.; Weaver, M.; Wisniewski, W. J.; Wittgen, M.; Wright, D. H.; Wulsin, H. W.; Yarritu, A. K.; Young, C. C.; Ziegler, V.; Park, W.; Purohit, M. V.; White, R. M.; Wilson, J. R.; Randle-Conde, A.; Sekula, S. J.; Bellis, M.; Burchat, P. R.; Miyashita, T. S.; Alam, M. S.; Ernst, J. A.; Gorodeisky, R.; Guttman, N.; Peimer, D. R.; Soffer, A.; Lund, P.; Spanier, S. M.; Eckmann, R.; Ritchie, J. L.; Ruland, A. M.; Schilling, C. J.; Schwitters, R. F.; Wray, B. C.; Izen, J. M.; Lou, X. C.; Bianchi, F.; Gamba, D.; Lanceri, L.; Vitale, L.; Lopez-March, N.; Martinez-Vidal, F.; Oyanguren, A.; Ahmed, H.; Albert, J.; Banerjee, Sw.; Choi, H. H. F.; King, G. J.; Kowalewski, R.; Lewczuk, M. J.; Lindsay, C.; Nugent, I. M.; Roney, J. M.; Sobie, R. J.; Gershon, T. J.; Harrison, P. F.; Latham, T. E.; Puccio, E. M. T.; Band, H. R.; Dasu, S.; Pan, Y.; Prepost, R.; Vuosalo, C. O.; Wu, S. L.

2012-07-01

We study the processes e+e-→K+K-π+π-γ, K+K-π0π0γ, and K+K-K+K-γ, where the photon is radiated from the initial state. About 84 000, 8000, and 4200 fully reconstructed events, respectively, are selected from 454fb-1 of BABAR data. The invariant mass of the hadronic final state defines the e+e- center-of-mass energy, so that the K+K-π+π-γ data can be compared with direct measurements of the e+e-→K+K-π+π- reaction. No direct measurements exist for the e+e-→K+K-π0π0 or e+e-→K+K-K+K- reactions, and we present an update of our previous result based on a data sample that is twice as large. Studying the structure of these events, we find contributions from a number of intermediate states and extract their cross sections. In particular, we perform a more detailed study of the e+e-→ϕ(1020)ππγ reaction and confirm the presence of the Y(2175) resonance in the ϕ(1020)f0(980) and K+K-f0(980) modes. In the charmonium region, we observe the J/ψ in all three final states and in several intermediate states, as well as the ψ(2S) in some modes, and measure the corresponding products of branching fraction and electron width.

Measurement of radiative proton capture on F 18 and implications for oxygen-neon novae reexamined

DOE Office of Scientific and Technical Information (OSTI.GOV)

Akers, C.; Laird, A. M.; Fulton, B. R.

The rate of the F-18(p, gamma)Ne-19 reaction affects the final abundance of the gamma-ray observable radioisotope F-18, produced in novae. However, no successful measurement of this reaction exists and the rate used is calculated from incomplete information on the contributing resonances. Of the two resonances thought to play a significant role, one has a radiative width estimated from the assumed analogue state in the mirror nucleus, F-19. The second does not have an analogue state assignment at all, resulting in an arbitrary radiative width being assumed. Here, we report the first successful direct measurement of the F-18(p, gamma)Ne-19 reaction. Themore » strength of the 665 keV resonance (E-x = 7.076 MeV) is found to be over an order of magnitude weaker than currently assumed in nova models. Reaction rate calculations show that this resonance therefore plays no significant role in the destruction of F-18 at any astrophysical energy.« less

Final Technical Report for Years 1-4 of the Early Career Research Project "Viscosity and equation of state of hot and dense QCD matter" - ARRA portion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Molnar, Denes

2014-04-14

The Section below summarizes research activities and achievements during the first four years of the PI’s Early Career Research Project (ECRP). Two main areas have been advanced: i) radiative 3 ↔ 2 radiative transport, via development of a new computer code MPC/Grid that solves the Boltzmann transport equation in full 6+1D (3X+3V+time) on both single-CPU and parallel computers; ii) development of a self-consistent framework to convert viscous fluids to particles, and application of this framework to relativistic heavy-ion collisions, in particular, determination of the shear viscosity. Year 5 of the ECRP is under a separate award number, and therefore itmore » has its own report document ’Final Technical Report for Year 5 of the Early Career Research Project “Viscosity and equation of state of hot and dense QCDmatter”’ (award DE-SC0008028). The PI’s group was also part of the DOE JET Topical Collaboration, a multi-institution project that overlapped in time significantly with the ECRP. Purdue achievements as part of the JET Topical Collaboration are in a separate report “Final Technical Report summarizing Purdue research activities as part of the DOE JET Topical Collaboration” (award DE-SC0004077).« less

Transient radiative transfer in a scattering slab considering polarization.

PubMed

Yi, Hongliang; Ben, Xun; Tan, Heping

2013-11-04

The characteristics of the transient and polarization must be considered for a complete and correct description of short-pulse laser transfer in a scattering medium. A Monte Carlo (MC) method combined with a time shift and superposition principle is developed to simulate transient vector (polarized) radiative transfer in a scattering medium. The transient vector radiative transfer matrix (TVRTM) is defined to describe the transient polarization behavior of short-pulse laser propagating in the scattering medium. According to the definition of reflectivity, a new criterion of reflection at Fresnel surface is presented. In order to improve the computational efficiency and accuracy, a time shift and superposition principle is applied to the MC model for transient vector radiative transfer. The results for transient scalar radiative transfer and steady-state vector radiative transfer are compared with those in published literatures, respectively, and an excellent agreement between them is observed, which validates the correctness of the present model. Finally, transient radiative transfer is simulated considering the polarization effect of short-pulse laser in a scattering medium, and the distributions of Stokes vector in angular and temporal space are presented.

Multi-jet Merging with NLO Matrix Elements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Siegert, Frank; /Freiburg U.; Hoche, Stefan

2011-08-18

In the algorithm presented here, the ME+PS approach to merge samples of tree-level matrix elements into inclusive event samples is combined with the POWHEG method, which includes exact next-to-leading order matrix elements in the parton shower. The advantages of the method are discussed and the quality of its implementation in SHERPA is exemplified by results for e{sup +}e{sup -} annihilation into hadrons at LEP, for deep-inelastic lepton-nucleon scattering at HERA, for Drell-Yan lepton-pair production at the Tevatron and for W{sup +}W{sup -}-production at LHC energies. The simulation of hard QCD radiation in parton-shower Monte Carlos has seen tremendous progress overmore » the last years. It was largely stimulated by the need for more precise predictions at LHC energies where the large available phase space allows additional hard QCD radiation alongside known Standard Model processes or even signals from new physics. Two types of algorithms have been developed, which allow to improve upon the soft-collinear approximations made in the parton shower, such that hard radiation is simulated according to exact matrix elements. In the ME+PS approach [1] higher-order tree-level matrix elements for different final-state jet multiplicity are merged with each other and with subsequent parton shower emissions to generate an inclusive sample. Such a prescription is invaluable for analyses which are sensitive to final states with a large jet multiplicity. The only remaining deficiency of such tree-level calculations is the large uncertainty stemming from scale variations. The POWHEG method [2] solves this problem for the lowest multiplicity subprocess by combining full NLO matrix elements with the parton shower. While this leads to NLO accuracy in the inclusive cross section and the exact radiation pattern for the first emission, it fails to describe higher-order emissions with improved accuracy. Thus it is not sufficient if final states with high jet multiplicities are considered. With the complementary advantages of these two approaches, the question arises naturally whether it would be possible to combine them into an even more powerful one. Such a combined algorithm was independently developed in [5] and [6]. Here a summary of the algorithm is given and predictions from corresponding Monte-Carlo predictions are presented.« less

LATE CONSEQUENCES WITH SMALL RONTGEN DOSES IN IRRADIATED CHILDREN (TENTATIVE REPORT) (in German)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stasek, V.; Jakoubkova, J.; Brachfeld, K.

The authors searched for late reactions of radiation in children and young people, between the ages of 2 months and 5 years, who had been radiated on account of nontumorous diseases in the region of the throat. Ten to 15 years after the radiation 52 children and young people were examined. The examinations were carried out from the standpoint of radiotherapy, oto-rhino-laryngology, x- ray diagnostics, and pediatrics. In not quite half of those examimed local changes were stated and considered as late radiation damages: In 11 of those examined were disturbances of endocrinal coordination. Its appearance is, in the asmore » yet small compilation, relatively high. Considering that the first observation of this kind is being dealt with, and that there are not sufficient objective criteria, the authors keep for themselves a final evaluation only after verification on a greater number of radiated children and a control group. (auth)« less

Dosimetric considerations for patients with HIP prostheses undergoing pelvic irradiation. Report of the AAPM Radiation Therapy Committee Task Group 63.

PubMed

Reft, Chester; Alecu, Rodica; Das, Indra J; Gerbi, Bruce J; Keall, Paul; Lief, Eugene; Mijnheer, Ben J; Papanikolaou, Nikos; Sibata, Claudio; Van Dyk, Jake

2003-06-01

This document is the report of a task group of the Radiation Therapy Committee of the AAPM and has been prepared primarily to advise hospital physicists involved in external beam treatment of patients with pelvic malignancies who have high atomic number (Z) hip prostheses. The purpose of the report is to make the radiation oncology community aware of the problems arising from the presence of these devices in the radiation beam, to quantify the dose perturbations they cause, and, finally, to provide recommendations for treatment planning and delivery. Some of the data and recommendations are also applicable to patients having implanted high-Z prosthetic devices such as pins, humeral head replacements. The scientific understanding and methodology of clinical dosimetry for these situations is still incomplete. This report is intended to reflect the current state of scientific understanding and technical methodology in clinical dosimetry for radiation oncology patients with high-Z hip prostheses.

Final Report for the Testing of the Y-12 Criticality Accident Alarm System Detectors at the Godiva IV Burst Reactor (IER-443)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Scorby, John C.; Hickman, David; Hudson, Becka

This report documents the experimental conditions and final results for the performance testing of the Y-12 Criticality Accident Alarm System (CAAS) detectors at the Godiva IV Burst Reactor at the National Criticality Experimental Research Center (NCERC) at the Nevada National Security Site (NNSS). The testing followed a previously issued test plan and was conducted during the week of July 17, 2017, with completion on Thursday July 20. The test subjected CAAS detectors supplied by Y-12 to very intense and short duration mixed neutron and gamma radiation fields to establish compliance to maximum radiation and minimum pulse width requirements. ANSI/ANS- 8.3.1997more » states that the “system shall be sufficiently robust as to actuate an alarm signal when exposed to the maximum radiation expected”, which has been defined at Y-12, in Documented Safety Analyses (DSAs), to be a dose rate of 10 Rad/s. ANSI/ANS-8.3.1997 further states that “alarm actuation shall occur as a result of a minimum duration transient” which may be assumed to be 1 msec. The pulse widths and dose rates provided by each burst during the test exceeded those requirements. The CAAS detectors all provided an immediate alarm signal and remained operable after the bursts establishing compliance to the requirements and fitness for re-deployment at Y-12.« less

Generalized one-loop neutrino mass model with charged particles

NASA Astrophysics Data System (ADS)

Cheung, Kingman; Okada, Hiroshi

2018-04-01

We propose a radiative neutrino-mass model by introducing 3 generations of fermion pairs E-(N +1 )/2E+(N +1 )/2 and a couple of multicharged bosonic doublet fields ΦN /2,ΦN /2 +1, where N =1 , 3, 5, 7, 9. We show that the models can satisfy the neutrino masses and oscillation data, and are consistent with lepton-flavor violations, the muon anomalous magnetic moment, the oblique parameters, and the beta function of the U (1 )Y hypercharge gauge coupling. We also discuss the collider signals for various N , namely, multicharged leptons in the final state from the Drell-Yan production of E-(N +1 )/2E+(N +1 )/2. In general, the larger the N the more charged leptons will appear in the final state.

Final-state QED multipole radiation in antenna parton showers

NASA Astrophysics Data System (ADS)

Kleiss, Ronald; Verheyen, Rob

2017-11-01

We present a formalism for a fully coherent QED parton shower. The complete multipole structure of photonic radiation is incorporated in a single branching kernel. The regular on-shell 2 → 3 kinematic picture is kept intact by dividing the radiative phase space into sectors, allowing for a definition of the ordering variable that is similar to QCD antenna showers. A modified version of the Sudakov veto algorithm is discussed that increases performance at the cost of the introduction of weighted events. Due to the absence of a soft singularity, the formalism for photon splitting is very similar to the QCD analogon of gluon splitting. However, since no color structure is available to guide the selection of a spectator, a weighted selection procedure from all available spectators is introduced.

Angular distributions in the reactions pp-->χ1,2-->γψ-->γe+e-

NASA Astrophysics Data System (ADS)

Baglin, C.; Baird, S.; Bassompierre, G.; Borreani, G.; Brient, J.-C.; Broll, C.; Brom, J.-M.; Bugge, L.; Buran, T.; Burq, J.-P.; Bussière, A.; Buzzo, A.; Cester, R.; Chemarin, M.; Chevallier, M.; Escoubes, B.; Fay, J.; Ferroni, S.; Gracco, V.; Guillad, J.-P.; Khan-Aronsen, E.; Kirsebom, K.; Kylling, A.; Ille, B.; Lambert, M.; Leistam, L.; Lundby, A.; Macri, M.; Marchetto, F.; Menichetti, E.; Morch, C.; Mouëllic, B.; Olsen, D.; Pastrone, N.; Petrillo, L.; Pia, M. G.; Poole, J.; Poulet, M.; Rinaudo, G.; Santroni, A.; Severi, M.; Skjevling, G.; Stugu, B.

1987-08-01

In the experiment R704 at the CERN Intersecting Storage Rings, the two p-wave charmonium states χ1 and χ2 were formed directly in proton-antiproton annihilation, and detected through the decay chain χj-->γ+J/ψ-->ψ+e+e-. The angular d istributions of the events found are studied here. A maximum likehood analysis shows that χ1 radiative transition to the J/ψ is compatible with a pure dipole. Indications of a nonzero, positive quadropole contribution to the χ2 radiative transition are found. Finally, it is found that the χ2 data are consistent with the conventional assumption that a single quark radiates the photon in the transition from the χ2 to the J/ψ.

The e{sup +}e{sup -}{yields}2({pi}{sup +}{pi}{sup -}){pi}{sup 0}, 2({pi}{sup +}{pi}{sup -}){eta}, K{sup +}K{sup -}{pi}{sup +}{pi}{sup -}{pi}{sup 0} and K{sup +}K{sup -}{pi}{sup +}{pi}{sup -}{eta} cross sections measured with initial-state radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aubert, B.; Bona, M.; Boutigny, D.

We study the processes e{sup +}e{sup -}{yields}2({pi}{sup +}{pi}{sup -}){pi}{sup 0}{gamma}, 2({pi}{sup +}{pi}{sup -}){eta}{gamma}, K{sup +}K{sup -}{pi}{sup +}{pi}{sup -}{pi}{sup 0}{gamma} and K{sup +}K{sup -}{pi}{sup +}{pi}{sup -}{eta}{gamma} with the hard photon radiated from the initial state. About 20 000, 4300, 5500, and 375 fully reconstructed events, respectively, are selected from 232 fb{sup -1} of BABAR data. The invariant mass of the hadronic final state defines the effective e{sup +}e{sup -} center-of-mass energy, so that the obtained cross sections from the threshold to about 5 GeV can be compared with corresponding direct e{sup +}e{sup -} measurements, currently available only for the {eta}{pi}{sup +}{pi}{supmore » -} and {omega}{pi}{sup +}{pi}{sup -} submodes of the e{sup +}e{sup -}{yields}2({pi}{sup +}{pi}{sup -}){pi}{sup 0} channel. Studying the structure of these events, we find contributions from a number of intermediate states, and we extract their cross sections where possible. In particular, we isolate the contribution from e{sup +}e{sup -}{yields}{omega}(782){pi}{sup +}{pi}{sup -} and study the {omega}(1420) and {omega}(1650) resonances. In the charmonium region, we observe the J/{psi} in all these final states and several intermediate states, as well as the {psi}(2S) in some modes, and we measure the corresponding branching fractions.« less

Cross Sections for the Reactions e+e to K+ K- pi+pi-, K+ K- pi0pi0, and K+ K- K+ K- Measured Using Initial-State Radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lees, J.P.; Poireau, V.; Prencipe, E.

2011-08-19

We study the processes e{sup +}e{sup -} {yields} K{sup +}K{sup -}{pi}{sup +}{pi}-{gamma}, K{sup +}K{sup -}{pi}{sup 0}{pi}{sup 0}{gamma}, and K{sup +}K{sup -}K{sup +}K{sup -}{gamma}, where the photon is radiated from the initial state. About 84000, 8000, and 4200 fully reconstructed events, respectively, are selected from 454 fb{sup -1} of BABAR data. The invariant mass of the hadronic final state defines the e{sup +}e{sup -} center-of-mass energy, so that the K{sup +}K{sup -}{pi}{sup +}{pi}{sup -}{gamma} data can be compared with direct measurements of the e{sup +}e{sup -} {yields} K{sup +}K{sup -}{pi}{sup +}{pi}{sup -} reaction. No direct measurements exist for the e{sup +}e{supmore » -} {yields} K{sup +}K{sup -}{pi}{sup 0}{pi}{sup 0} or e{sup +}e{sup -} {yields} K{sup +}K{sup -}K{sup +}K{sup -} reactions, and we present an update of our previous result with doubled statistics. Studying the structure of these events, we find contributions from a number of intermediate states, and extract their cross sections. In particular, we perform a more detailed study of the e{sup +}e{sup -} {yields} {phi}(1020){pi}{pi}{gamma} reaction, and confirm the presence of the Y (2175) resonance in the {phi}(1020)f{sub 0}(980) and K{sup +}K{sup -} f{sub 0}(980) modes. In the charmonium region, we observe the J/{psi} in all three final states and in several intermediate states, as well as the {phi}(2S) in some modes, and measure the corresponding branching fractions.« less

The effective Tolman temperature in curved spacetimes

NASA Astrophysics Data System (ADS)

Kim, Wontae

We review a recently proposed effective Tolman temperature and present its applications to various gravitational systems. In the Unruh state for the evaporating black holes, the free-fall energy density is found to be negative divergent at the horizon, which is in contrast to the conventional calculations performed in the Kruskal coordinates. We resolve this conflict by invoking that the Kruskal coordinates could be no longer proper coordinates at the horizon. In the Hartle-Hawking-Israel state, despite the negative finite proper energy density at the horizon, the Tolman temperature is divergent there due to the infinite blueshift of the Hawking temperature. However, a consistent Stefan-Boltzmann law with the Hawking radiation shows that the effective Tolman temperature is eventually finite everywhere and the equivalence principle is surprisingly restored at the horizon. Then, we also show that the firewall necessarily emerges out of the Unruh vacuum, so that the Tolman temperature in the evaporating black hole is naturally divergent due to the infinitely blueshifted negative ingoing flux crossing the horizon, whereas the outgoing Hawking radiation characterized by the effective Tolman temperature indeed originates from the quantum atmosphere, not just at the horizon. So, the firewall and the atmosphere for the Hawking radiation turn out to be compatible, once we discard the fact that the Hawking radiation in the Unruh state originates from the infinitely blueshifted outgoing excitations at the horizon. Finally, as a cosmological application, the initial radiation energy density in warm inflation scenarios has been assumed to be finite when inflation starts. We successfully find the origin of the nonvanishing initial radiation energy density in the warm inflation by using the effective Tolman temperature.

Maximal near-field radiative heat transfer between two plates

NASA Astrophysics Data System (ADS)

Nefzaoui, Elyes; Ezzahri, Younès; Drévillon, Jérémie; Joulain, Karl

2013-09-01

Near-field radiative transfer is a promising way to significantly and simultaneously enhance both thermo-photovoltaic (TPV) devices power densities and efficiencies. A parametric study of Drude and Lorentz models performances in maximizing near-field radiative heat transfer between two semi-infinite planes separated by nanometric distances at room temperature is presented in this paper. Optimal parameters of these models that provide optical properties maximizing the radiative heat flux are reported and compared to real materials usually considered in similar studies, silicon carbide and heavily doped silicon in this case. Results are obtained by exact and approximate (in the extreme near-field regime and the electrostatic limit hypothesis) calculations. The two methods are compared in terms of accuracy and CPU resources consumption. Their differences are explained according to a mesoscopic description of nearfield radiative heat transfer. Finally, the frequently assumed hypothesis which states a maximal radiative heat transfer when the two semi-infinite planes are of identical materials is numerically confirmed. Its subsequent practical constraints are then discussed. Presented results enlighten relevant paths to follow in order to choose or design materials maximizing nano-TPV devices performances.

Radiative Decay Width of Neutral non-Strange Baryons from PWA

NASA Astrophysics Data System (ADS)

Strakovsky, Igor I.; Briscoe, William J.; Kudryavtsev, Alexander E.; Kulikov, Viacheslav V.; Martemyanov, Maxim A.; Tarasov, Vladimir E.

2015-06-01

An overview of the GW SAID and ITEP groups effort to analyze pion photoproduction on the neutron-target will be given. The disentanglement the isoscalar and isovector EM couplings of N∗ and Δ∗ resonances does require compatible data on both proton and neutron targets. The final-state interaction plays a critical role in the state-of-the-art analysis in extraction of the γn → πN data from the deuteron target experiments. It is important component of the current JLab, MAMI-C, SPring-8, ELSA, and ELPH programs.

Cross-Section Parameterizations for Pion and Nucleon Production From Negative Pion-Proton Collisions

NASA Technical Reports Server (NTRS)

Norbury, John W.; Blattnig, Steve R.; Norman, Ryan; Tripathi, R. K.

2002-01-01

Ranft has provided parameterizations of Lorentz invariant differential cross sections for pion and nucleon production in pion-proton collisions that are compared to some recent data. The Ranft parameterizations are then numerically integrated to form spectral and total cross sections. These numerical integrations are further parameterized to provide formula for spectral and total cross sections suitable for use in radiation transport codes. The reactions analyzed are for charged pions in the initial state and both charged and neutral pions in the final state.

Multiple core-hole formation by free-electron laser radiation in molecular nitrogen

NASA Astrophysics Data System (ADS)

Banks, H. I. B.; Little, D. A.; Emmanouilidou, A.

2018-05-01

We investigate the formation of multiple-core-hole states of molecular nitrogen interacting with a free-electron laser pulse. In previous work, we obtained bound and continuum molecular orbitals in the single-center expansion scheme and used these orbitals to calculate photo-ionization and auger decay rates. We extend our formulation to track the proportion of the population that accesses single-site versus two-site double-core-hole (TSDCH) states, before the formation of the final atomic ions. We investigate the pulse parameters that favor the formation of the single-site and TSDCH as well as triple-core-hole states for 525 and 1100 eV photons.

Practice Patterns Regarding Multidisciplinary Cancer Management and Suggestions for Further Refinement: Results from a National Survey in Korea.

PubMed

Lee, Yun-Gyoo; Oh, Sukjoong; Kimm, Heejin; Koo, Dong-Hoe; Kim, Do Yeun; Kim, Bong-Seog; Lee, Seung-Sei

2017-10-01

This study was conducted to explore the process and operation of a cancer multidisciplinary team (MDT) after the reimbursement decision in Korea, and to identify ways to overcome the major barriers to effective and sustainable MDTs. Approximately 1,000 cancer specialists, including medical oncologists, surgical oncologists, radiation oncologists, pathologists, and radiologists in general hospitals in Koreawere invited to complete the survey. The questionnaire covered the following topics: organizational structure of MDTs, candidates for consulting, the clinical decision-making initiative, and responsibility for dealing with legal disputes. We collected a total of 179 responses (18%) from physicians at institutions where an MDT approach was active. A surgical oncologist (91%), internist (90%),radiologist (89%),radiation oncologist (86%), pathologist (71%), and trainees (20%) regularly participated in MDT operations. Approximately 55% of respondents stated that MDTs met regularly. In cases of a split opinion, the physician in charge (69%) or chairperson (17%) made the final decision, and most (86%) stated they followed the final decision. About 15% and 32% of respondents were "very satisfied" and "satisfied," respectively, with the current MDT's operations. Among 38 institutional representatives, 34% responded that the MDT operation became more active and 18% stated an MDT was newly implemented after the reimbursement decision. The reimbursement decision invigorated MDT operations in almost half of eligible hospitals. Dissatisfaction regarding current MDTs was over 50%, and the high discordance rates regarding risk sharing suggest that it is necessary to revise the current system of MDTs.

Solar Arrays for Low-Irradiance Low-Temperature and High-Radiation Environments

NASA Technical Reports Server (NTRS)

Boca, Andreea (Principal Investigator); Stella, Paul; Kerestes, Christopher; Sharps, Paul

2017-01-01

This is the Base Period final report DRAFT for the JPL task 'Solar Arrays for Low-Irradiance Low-Temperature and High-Radiation Environments', under Task Plan 77-16518 TA # 21, for NASA's Extreme Environments Solar Power (EESP) project. This report covers the Base period of performance, 7/18/2016 through 5/2/2017.The goal of this project is to develop an ultra-high efficiency lightweight scalable solar array technology for low irradiance, low temperature and high-radiation (LILT/Rad) environments. The benefit this technology will bring to flight systems is a greater than 20 reduction in solar array surface area, and a six-fold reduction in solar array mass and volume. The EESP project objectives are summarized in the 'NRA Goal' column of Table 1. Throughout this report, low irradiance low temperature (LILT) refers to 5AU -125 C test conditions; beginning of life (BOL) refers to the cell state prior to radiation exposure; and end of life (EOL) refers to the test article condition after exposure to a radiation dose of 4e15 1MeV e(-)/cm(exp 2).

The cooling of confined ions driven by laser beams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reyna, L.G.; Sobehart, J.R.

1993-07-01

We finalize the dynamics of confined ions driven by a quantized radiation field. The ions can absorb photons from an incident laser beam and relax back to the ground state by either induced emissions or spontaneous emissions. Here we assume that the absorption of photons is immediately followed by spontaneous emissions, resulting in single-level ions perturbed by the exchange of momentum with the radiation field. The probability distribution of the ions is calculated using singular expansions in the low noise asymptotic limit. The present calculations reproduce the quantum results in the limit of heavy particles in static traps, and themore » classical results of ions in radio-frequency confining wells.« less

Final Report: SciDAC Computational Astrophysics Consortium (at Princeton University)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burrows, Adam

Supernova explosions are the central events in astrophysics. They are the major agencies of change in the interstellar medium, driving star formation and the evolution of galaxies. Their gas remnants are the birthplaces of the cosmic rays. Such is their brightness that they can be used as standard candles to measure the size and geometry of the universe and their investigation draws on particle and nuclear physics, radiative transfer, kinetic theory, gravitational physics, thermodynamics, and the numerical arts. Hence, supernovae are unrivaled astrophysical laboratories. We will develop new state-of-the-art multi-dimensional radiation hydrodynamic codes to address this and other related astrophysicalmore » phenomena.« less

The Lyman-alpha signature of the first galaxies

NASA Astrophysics Data System (ADS)

Smith, Aaron

2018-01-01

Radiation from the first stars and galaxies initiated the dramatic phase transition marking an end to the cosmic dark ages. The emission and absorption signatures from the Lyman-alpha (Lyα) transition of neutral hydrogen have been indispensable in extending the observational frontier for high-redshift galaxies into the epoch of reionization. Lyα radiative transfer provides clues about the processes leading to Lyα escape from individual galaxies and the subsequent transmission through the intergalactic medium. Cosmological simulations incorporating Lyα radiative transfer enhance our understanding of fundamental physics by supplying the inferred spectra and feedback on the gas. In this talk, I will discuss the dynamical impact of Lyα radiation pressure on galaxy formation throughout cosmic reionization with the first fully coupled Lyα radiation-hydrodynamics simulations. Based on a suite of spherically symmetric models and high-resolution ab initio cosmological simulations we find that Lyα radiation pressure is dynamically important during the assembly of direct collapse black holes (DCBHs), which may be the seeds of the first supermassive black holes in the universe. Finally, I will discuss recent advances in Lyα modeling based on current state-of-the-art simulations and observational insights.

Hierarchical data-driven approach to fitting numerical relativity data for nonprecessing binary black holes with an application to final spin and radiated energy

NASA Astrophysics Data System (ADS)

Jiménez-Forteza, Xisco; Keitel, David; Husa, Sascha; Hannam, Mark; Khan, Sebastian; Pürrer, Michael

2017-03-01

Numerical relativity is an essential tool in studying the coalescence of binary black holes (BBHs). It is still computationally prohibitive to cover the BBH parameter space exhaustively, making phenomenological fitting formulas for BBH waveforms and final-state properties important for practical applications. We describe a general hierarchical bottom-up fitting methodology to design and calibrate fits to numerical relativity simulations for the three-dimensional parameter space of quasicircular nonprecessing merging BBHs, spanned by mass ratio and by the individual spin components orthogonal to the orbital plane. Particular attention is paid to incorporating the extreme-mass-ratio limit and to the subdominant unequal-spin effects. As an illustration of the method, we provide two applications, to the final spin and final mass (or equivalently: radiated energy) of the remnant black hole. Fitting to 427 numerical relativity simulations, we obtain results broadly consistent with previously published fits, but improving in overall accuracy and particularly in the approach to extremal limits and for unequal-spin configurations. We also discuss the importance of data quality studies when combining simulations from diverse sources, how detailed error budgets will be necessary for further improvements of these already highly accurate fits, and how this first detailed study of unequal-spin effects helps in choosing the most informative parameters for future numerical relativity runs.

Entanglement transfer from microwaves to diamond NV centers

NASA Astrophysics Data System (ADS)

Gomez, Angela V.; Rodriguez, Ferney J.; Quiroga, Luis

2014-03-01

Strong candidates to create quantum entangled states in solid-state environments are the nitrogen-vacancy (NV) defect centers in diamond. By the combination of radiation from different wavelength (optical, microwave and radio-frequency), several protocols have been proposed to create entangled states of different NVs. Recently, experimental sources of non-classical microwave radiation have been successfully realized. Here, we consider the entanglement transfer from spatially separated two-mode microwave squeezed (entangled) photons to a pair of NV centers by exploiting the fact that the spin triplet ground state of a NV has a natural splitting with a frequency on the order of GHz (microwave range). We first demonstrate that the transfer process in the simplest case of a single pair of spatially separated NVs is feasible. Moreover, we proceed to extend the previous results to more realistic scenarios where 13C nuclear spin baths surrounding each NV are included, quantifying the degradation of the entanglement transfer by the dephasing/dissipation effects produced by the nuclear baths. Finally, we address the issue of assessing the possibility of entanglement transfer from the squeezed microwave light to two nuclear spins closely linked to different NV center electrons. Facultad de Ciencias Uniandes.

Propagation of a shock wave in a radiating spherically symmetric distribution of matter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Herrera, L.; Nunez, L.

1987-08-01

A method used to study the evolution of radiating spheres reported by Herrera et al. (1980) is extended to the case in which the sphere is divided in two regions by a shock wave front. The equations of state at both sides of the shock are different, and the solutions are matched on it via the Rankine-Hugoniot conditions. The outer-region metric is matched with a Vaidya solution on the boundary surface of the sphere. As an example of the procedure, two known solutions for radiating systems are considered. The matter distribution is free of singularities everywhere within the sphere andmore » a Gaussian-like pulse is assumed to carry out a fraction of the total mass. Exploding models are then obtained. Finally, the results are discussed in the light of recent work on gravitational collapse and supernovae. 29 references.« less

Numerical simulation of turbulent jet noise, part 2

NASA Technical Reports Server (NTRS)

Metcalfe, R. W.; Orszag, S. A.

1976-01-01

Results on the numerical simulation of jet flow fields were used to study the radiated sound field, and in addition, to extend and test the capabilities of the turbulent jet simulation codes. The principal result of the investigation was the computation of the radiated sound field from a turbulent jet. In addition, the computer codes were extended to account for the effects of compressibility and eddy viscosity, and the treatment of the nonlinear terms of the Navier-Stokes equations was modified so that they can be computed in a semi-implicit way. A summary of the flow model and a description of the numerical methods used for its solution are presented. Calculations of the radiated sound field are reported. In addition, the extensions that were made to the fundamental dynamical codes are described. Finally, the current state-of-the-art for computer simulation of turbulent jet noise is summarized.

Collisional redistribution of radiation. II - The effects of degeneracy on the equations of motion for the density matrix. III - The equation of motion for the correlation function and the scattered spectrum

NASA Technical Reports Server (NTRS)

Burnett, K.; Cooper, J.

1980-01-01

The effect of correlations between an absorber atom and perturbers in the binary-collision approximation are applied to degenerate atomic systems. A generalized absorption profile which specifies the final state of the atom after an absorption event is related to the total intensities of Rayleigh scattering and fluorescence from the atom. It is suggested that additional dynamical information to that obtainable from ordinary absorption experiments is required in order to describe redistributed atomic radiation. The scattering of monochromatic radiation by a degenerate atom is computed in a binary-collision approximation; an equation of motion is derived for the correlation function which is valid outside the quantum-regression regime. Solutions are given for the weak-field conditions in terms of generalized absorption and emission profiles that depend on the indices of the atomic multipoles.

Evidence for final state photons in multihadronic decays of the Z 0

NASA Astrophysics Data System (ADS)

Akrawy, M. Z.; Alexander, G.; Allison, J.; Allport, P. P.; Anderson, K. J.; Armitage, J. C.; Arnison, G. T. J.; Ashton, P.; Azuelos, G.; Baines, J. T. M.; Ball, A. H.; Banks, J.; Barker, G. J.; Barlow, R. J.; Batley, J. R.; Becker, J.; Behnke, T.; Bell, K. W.; Bella, G.; Bethke, S.; Biebel, O.; Binder, U.; Bloodworth, I. J.; Bock, P.; Breuker, H.; Brown, R. M.; Brun, R.; Buijs, A.; Burckhart, H. J.; Capiluppi, P.; Carnegie, R. K.; Carter, A. A.; Carter, J. R.; Chang, C. Y.; Charlton, D. G.; Chrin, J. T. M.; Cohen, I.; Collins, W. J.; Conboy, J. E.; Couch, M.; Coupland, M.; Cuffiani, M.; Dado, S.; Dallavalle, G. M.; Debu, P.; Deninno, M. M.; Dieckmann, A.; Dittmar, M.; Dixit, M. S.; Duchovni, E.; Duerdoth, I. P.; Dumas, D.; El Mamouni, H.; Elcombe, P. A.; Estabrooks, P. G.; Etzion, E.; Fabbri, F.; Farthouat, P.; Fischer, H. M.; Fong, D. G.; French, M. T.; Fukunaga, C.; Gaidot, A.; Ganel, O.; Gary, J. W.; Gascon, J.; Geddes, N. I.; Gee, C. N. P.; Geich-Gimbel, C.; Gensler, S. W.; Gentit, F. X.; Giacomelli, G.; Gibson, V.; Gibson, W. R.; Gillies, J. D.; Goldberg, J.; Goodrick, M. J.; Gorn, W.; Granite, D.; Gross, E.; Grosse-Wiesmann, P.; Grunhaus, J.; Hagedorn, H.; Hagemann, J.; Hansroul, M.; Hargrove, C. K.; Hart, J.; Hattersley, P. M.; Hauschild, M.; Hawkes, C. M.; Heflin, E.; Hemingway, R. J.; Heuer, R. D.; Hill, J. C.; Hillier, S. J.; Ho, C.; Hobbs, J. D.; Hobson, P. R.; Hochman, D.; Holl, B.; Homer, R. J.; Hou, S. R.; Howarth, C. P.; Hughes-Jones, R. E.; Igo-Kemenes, P.; Ihssen, H.; Imrie, D. C.; Jawahery, A.; Jeffreys, P. W.; Jeremie, H.; Jimack, M.; Jobes, M.; Jones, R. W. L.; Jovanovic, P.; Karlen, D.; Kawagoe, K.; Kawamoto, T.; Kellogg, R. G.; Kennedy, B. W.; Kleinwort, C.; Klem, D. E.; Knop, G.; Kobayashi, T.; Kokott, T. P.; Köpke, L.; Kowalewski, R.; Kreutzmann, H.; von Krogh, J.; Kroll, J.; Kuwano, M.; Kyberd, P.; Lafferty, G. D.; Lamarche, F.; Larson, W. J.; Lasota, M. M. B.; Layter, J. G.; Le Du, P.; Leblanc, P.; Lee, A. M.; Lellouch, D.; Lennert, P.; Lessard, L.; Levinson, L.; Lloyd, S. L.; Loebinger, F. K.; Lorah, J. M.; Lorazo, B.; Losty, M. J.; Ludwig, J.; Lupu, N.; Ma, J.; Macbeth, A. A.; Mannelli, M.; Marcellini, S.; Maringer, G.; Martin, A. J.; Martin, J. P.; Mashimo, T.; Mättig, P.; Maur, U.; McMahon, T. J.; McPherson, A. C.; Meijers, F.; Menszner, D.; Merritt, F. S.; Mes, H.; Michelini, A.; Middleton, R. P.; Mikenberg, G.; Miller, D. J.; Milstene, C.; Minowa, M.; Mohr, W.; Montanari, A.; Mori, T.; Moss, M. W.; Murphy, P. G.; Murray, W. J.; Nellen, B.; Nguyen, H. H.; Nozaki, M.; O'Dowd, A. J. P.; O'Neale, S. W.; O'Neill, B. P.; Oakham, F. G.; Odorici, F.; Ogg, M.; Oh, H.; Oreglia, M. J.; Orito, S.; Pansart, J. P.; Patrick, G. N.; Pawley, S. J.; Pfister, P.; Pilcher, J. E.; Pinfold, J. L.; Plane, D. E.; Poli, B.; Pouladdej, A.; Pritchard, T. W.; Quast, G.; Raab, J.; Redmond, M. W.; Rees, D. L.; Regimbald, M.; Riles, K.; Roach, C. M.; Robins, S. A.; Rollnik, A.; Roney, J. M.; Rossberg, S.; Rossi, A. M.; Routenburg, P.; Runge, K.; Runolfsson, O.; Sanghera, S.; Sansum, R. A.; Sasaki, M.; Saunders, B. J.; Schaile, A. D.; Schaile, O.; Schappert, W.; Scharff-Hansen, P.; von der Schmitt, H.; Schreiber, S.; Schwarz, J.; Shapira, A.; Shen, B. C.; Sherwood, P.; Simon, A.; Siroli, G. P.; Skuja, A.; Smith, A. M.; Smith, T. J.; Snow, G. A.; Spreadbury, E. J.; Springer, R. W.; Sproston, M.; Stephens, K.; Stier, H. E.; Ströhmer, R.; Strom, D.; Takeda, H.; Takeshita, T.; Tsukamoto, T.; Turner, M. F.; Tysarczyk-Niemeyer, G.; Van den plas, D.; VanDalen, G. J.; Vasseur, G.; Virtue, C. J.; Wagner, A.; Wahl, C.; Ward, C. P.; Ward, D. R.; Waterhouse, J.; Watkins, P. M.; Watson, A. T.; Watson, N. K.; Weber, M.; Weisz, S.; Wermes, N.; Weymann, M.; Wilson, G. W.; Wilson, J. A.; Wingerter, I.; Winterer, V.-H.; Wood, N. C.; Wotton, S.; Wuensch, B.; Wyatt, T. R.; Yaari, R.; Yang, Y.; Yekutieli, G.; Yoshida, T.; Zeuner, W.; Zorn, G. T.; OPAL Collaboration

1990-08-01

From the observed yield and properties of isolated energetic photons in the reaction e +e -→Z 0→hadrons+ γ measured with the OPAL detector at LEP, evidence for final state radiation from primary quarks is obtained. Combined with the measurement of the total hadronic width of the Z 0, the observed rate allows the extraction of the electroweak coupling constants of up and down type quarks: ν {1}/{3}2 + a {1}/{3}2 = 1.24±0.47 and ν {2}/{3}2 + a {2}/{3}2 = 1.72±0.70 No evidence for additional photon production from anomalous decays of the Z 0 or from decays of new particles is found. This measurement limits the contribution to the total Z 0 width from such sources to be less than 8.2 MeV at the 95% confidence level.

Particle definitions and the information loss paradox

NASA Astrophysics Data System (ADS)

Venditti, Alex

An investigation of information loss in black hole spacetimes is performed. We demonstrate that the definition of particles as energy levels of the Harmonic oscillator will not have physical significance in general and is thus not a good instrument to study the radiation of black holes. This is due to the ambiguity of the choice of coordinates on the phase space of the quantum field. We demonstrate how to identify quantum states in the functional Schrodinger picture. We demonstrate that information is truly lost in the case of a Vaidya black hole (a black hole formed from null dust) if we neglect back reaction. This is done by quantizing the constrained classical system of a Klein-Gordon field in a Vaidya background. The interaction picture of quantum mechanics can be applied to this system. We find a physically well motivated vacuum state for a spherically symmetric spacetime with an extra conformal Killing vector. We also demonstrate how to calculate the response of a particle detector in the a LeMaitre-Tolman-Bondi spacetime with a selfsimilarity. Finally, some of the claims and confusion surrounding Unruh radiation, Hawking radiation and the equivalence principle are investigated and shown to be false.

Dielectronic recombination data for dynamic finite-density plasmas. XV. The silicon isoelectronic sequence

NASA Astrophysics Data System (ADS)

Kaur, Jagjit; Gorczyca, T. W.; Badnell, N. R.

2018-02-01

Context. We aim to present a comprehensive theoretical investigation of dielectronic recombination (DR) of the silicon-like isoelectronic sequence and provide DR and radiative recombination (RR) data that can be used within a generalized collisional-radiative modelling framework. Aims: Total and final-state level-resolved DR and RR rate coefficients for the ground and metastable initial levels of 16 ions between P+ and Zn16+ are determined. Methods: We carried out multi-configurational Breit-Pauli DR calculations for silicon-like ions in the independent processes, isolated resonance, distorted wave approximation. Both Δnc = 0 and Δnc = 1 core excitations are included using LS and intermediate coupling schemes. Results: Results are presented for a selected number of ions and compared to all other existing theoretical and experimental data. The total dielectronic and radiative recombination rate coefficients for the ground state are presented in tabulated form for easy implementation into spectral modelling codes. These data can also be accessed from the Atomic Data and Analysis Structure (ADAS) OPEN-ADAS database. This work is a part of an assembly of a dielectronic recombination database for the modelling of dynamic finite-density plasmas.

Morphology and mixing state of atmospheric particles: Links to optical properties and cloud processing

NASA Astrophysics Data System (ADS)

China, Swarup

Atmospheric particles are ubiquitous in Earth's atmosphere and impact the environment and the climate while affecting human health and Earth's radiation balance, and degrading visibility. Atmospheric particles directly affect our planet's radiation budget by scattering and absorbing solar radiation, and indirectly by interacting with clouds. Single particle morphology (shape, size and internal structure) and mixing state (coating by organic and inorganic material) can significantly influence the particle optical properties as well as various microphysical processes, involving cloud-particle interactions and including heterogeneous ice nucleation and water uptake. Conversely, aerosol cloud processing can affect the morphology and mixing of the particles. For example, fresh soot has typically an open fractal-like structure, but aging and cloud processing can restructure soot into more compacted shapes, with different optical and ice nucleation properties. During my graduate research, I used an array of electron microscopy and image analysis tools to study morphology and mixing state of a large number of individual particles collected during several field and laboratory studies. To this end, I investigated various types of particles such as tar balls (spherical carbonaceous particles emitted during biomass burning) and dust particles, but with a special emphasis on soot particles. In addition, I used the Stony Brook ice nucleation cell facility to investigate heterogeneous ice nucleation and water uptake by long-range transported particles collected at the Pico Mountain Observatory, in the Archipelago of the Azores. Finally, I used ice nucleation data from the SAAS (Soot Aerosol Aging Study) chamber study at the Pacific Northwest National Laboratory to understand the effects that ice nucleation and supercooled water processing has on the morphology of residual soot particles. Some highlights of our findings and implications are discussed next. We found that the morphology of fresh soot emitted by vehicles depends on the driving conditions (i.e.; the vehicle specific power). Soot emitted by biomass burning is often heavily coated by other materials while processing of soot in urban environment exhibits complex mixing. We also found that long-range transported soot over the ocean after atmospheric processing is very compacted. In addition, our results suggest that freezing process can facilitate restructuring of soot and results into collapsed soot. Furthermore, numerical simulations showed strong influence on optical properties when fresh open fractal-like soot evolved to collapsed soot. Further investigation of long-range transported aged particles exhibits that they are efficient in water uptake and can induce ice nucleation in colder temperature. Our results have implications for assessing the impact of the morphology and mixing state of soot particles on human health, environment and climate. Our findings can provide guidance to numerical models such as particle-resolved mixing state models to account for, and better understand, vehicular emissions and soot evolution since its emission to atmospheric processing in urban environment and finally in remote regions after long-range transport. Morphology and mixing state information can be used to model observational-constrained optical properties. The details of morphology and mixing state of soot particles are crucial to assess the accuracy of climate models in describing the contribution of soot radiative forcing and their direct and indirect climate effects. Finally, our observations of ice nucleation ability by aged particles show that nucleated particles are internally mixed and coated with several materials.

Electronic spectroscopy of diatomic molecules

NASA Technical Reports Server (NTRS)

Partridge, Harry; Langhoff, Stephen R.; Bauschlicher, Charles W., Jr.

1994-01-01

This article provides an overview of the principal computational approaches and their accuracy for the study of electronic spectroscopy of diatomic molecules. We include a number of examples from our work that illustrate the range of application. We show how full configuration interaction benchmark calculations were instrumental in improving the understanding of the computational requirements for obtaining accurate results for diatomic spectroscopy. With this understanding it is now possible to compute radiative lifetimes accurate to within 10% for systems involving first- and second-row atoms. We consider the determination of the infrared vibrational transition probabilities for the ground states of SiO and NO, based on a globally accurate dipole moment function. We show how we were able to assign the a(sup "5)II state of CO as the upper state in the recently observed emission bands of CO in an Ar matrix. We next discuss the assignment of the photoelectron detachment spectra of NO and the alkali oxide negative ions. We then present several examples illustrating the state-of-the-art in determining radiative lifetimes for valence-valence and valence-Rydberg transitions. We next compare the molecular spectroscopy of the valence isoelectronic B2, Al2, and AlB molecules. The final examples consider systems involving transition metal atoms, which illustrate the difficulty in describing states with different numbers of d electrons.

Probable Rotation States of Rocket Bodies in Low Earth Orbit

NASA Technical Reports Server (NTRS)

Ojakangas, Gregory W.; Anz-Meador, P.; Cowardin, H.

2012-01-01

In order for Active Debris Removal to be accomplished, it is critically important to understand the probable rotation states of orbiting, spent rocket bodies. As compared to the question of characterizing small unresolved debris, in this problem there are several advantages: (1) objects are of known size, mass, shape and color, (2) they have typically been in orbit for a known period of time, (3) they are large enough that resolved images may be obtainable for verification of predicted orientation, and (4) the dynamical problem is simplified to first order by largely cylindrical symmetry. It is also nearly certain for realistic rocket bodies that internal friction is appreciable in the case where residual liquid or, to a lesser degree, unconsolidated solid fuels exist. Equations of motion have been developed for this problem in which internal friction as well as torques due to solar radiation, magnetic induction, and gravitational gradient are included. In the case of pure cylindrical symmetry, the results are compared to analytical predictions patterned after the standard approach for analysis of symmetrical tops. This is possible because solar radiation and gravitational torques may be treated as conservative. Agreement between results of both methods ensures their mutual validity. For monotone symmetric cylinders, solar radiation torque vanishes if the center of mass resides at the geometric center of the object. Results indicate that in the absence of solar radiation effects, rotation states tend toward an equilibrium configuration in which rotation is about the axis of maximum inertia, with the axis of minimum inertia directed toward the center of the earth. Solar radiation torque introduces a modification to this orientation. The equilibrium state is asymptotically approached within a characteristic timescale given by a simple ratio of relevant characterizing parameters for the body in question. Light curves are simulated for the expected asymptotic final rotation states of model objects, and these are compared to data derived from physical models of the same objects, tested in the Optical Measurements Center at JSC. Comparison to relevant light curves from actual orbiting rocket bodies are also performed, and diagnostic features of such curves are examined.

Coherent Radiation in Atomic Systems

NASA Astrophysics Data System (ADS)

Sutherland, Robert Tyler

Over the last century, quantum mechanics has dramatically altered our understanding of light and matter. Impressively, exploring the relationship between the two continues to provide important insights into the physics of many-body systems. In this thesis, we add to this still growing field of study. Specifically, we discuss superradiant line-broadening and cooperative dipole-dipole interactions for cold atom clouds in the linear-optics regime. We then discuss how coherent radiation changes both the photon scattering properties and the excitation distribution of atomic arrays. After that, we explore the nature of superradiance in initially inverted clouds of multi-level atoms. Finally, we explore the physics of clouds with degenerate Zeeman ground states, and show that this creates quantum effects that fundamentally change the photon scattering of atomic ensembles.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rist, J.; Miteva, T.; Gaire, B.

In this paper we present a comprehensive and detailed study of Interatomic Coulombic Decay (ICD) occurring after irradiating argon dimers with XUV-synchrotron radiation. A manifold of different decay channels is observed and the corresponding initial and final states are assigned. Additionally, the effect of nuclear dynamics on the ICD electron spectrum is examined for one specific decay channel. The internuclear distance-dependent width Γ(R) of the decay is obtained from the measured kinetic energy release distribution of the ions employing a classical nuclear dynamics model.

Spin-Orbit Mediated Interference in the Radiative and Nonradiative Channels of the La 4d Core Resonances

NASA Astrophysics Data System (ADS)

Suljoti, E.; de Groot, F. M. F.; Nagasono, M.; Glatzel, P.; Hennies, F.; Deppe, M.; Pietzsch, A.; Sonntag, B.; Föhlisch, A.; Wurth, W.

2009-09-01

Symmetrical fluorescence yield profiles and asymmetrical electron yield profiles of the preresonances at the La NIV,V x-ray absorption edge are experimentally observed in LaPO4 nanoparticles. Theoretical studies show that they are caused by interference effects. The spin-orbit interaction and the giant resonance produce symmetry entangled intermediate states that activate coherent scattering and alter the spectral distribution of the oscillator strength. The scattering amplitudes of the electron and fluorescence decays are further modified by the spin-orbit coupling in the final 5p5ɛl and 5p54f1 states.

First observation of exclusive χcJ decays to two charged and two neutral hadrons

NASA Astrophysics Data System (ADS)

He, Q.; Insler, J.; Muramatsu, H.; Park, C. S.; Thorndike, E. H.; Yang, F.; Artuso, M.; Blusk, S.; Khalil, S.; Li, J.; Menaa, N.; Mountain, R.; Nisar, S.; Randrianarivony, K.; Sia, R.; Sultana, N.; Skwarnicki, T.; Stone, S.; Wang, J. C.; Zhang, L. M.; Bonvicini, G.; Cinabro, D.; Dubrovin, M.; Lincoln, A.; Asner, D. M.; Edwards, K. W.; Naik, P.; Briere, R. A.; Ferguson, T.; Tatishvili, G.; Vogel, H.; Watkins, M. E.; Rosner, J. L.; Adam, N. E.; Alexander, J. P.; Cassel, D. G.; Duboscq, J. E.; Ehrlich, R.; Fields, L.; Gibbons, L.; Gray, R.; Gray, S. W.; Hartill, D. L.; Heltsley, B. K.; Hertz, D.; Jones, C. D.; Kandaswamy, J.; Kreinick, D. L.; Kuznetsov, V. E.; Mahlke-Krüger, H.; Mohapatra, D.; Onyisi, P. U. E.; Patterson, J. R.; Peterson, D.; Riley, D.; Ryd, A.; Sadoff, A. J.; Shi, X.; Stroiney, S.; Sun, W. M.; Wilksen, T.; Athar, S. B.; Patel, R.; Yelton, J.; Rubin, P.; Eisenstein, B. I.; Karliner, I.; Mehrabyan, S.; Lowrey, N.; Selen, M.; White, E. J.; Wiss, J.; Mitchell, R. E.; Shepherd, M. R.; Besson, D.; Pedlar, T. K.; Cronin-Hennessy, D.; Gao, K. Y.; Hietala, J.; Kubota, Y.; Klein, T.; Lang, B. W.; Poling, R.; Scott, A. W.; Zweber, P.; Dobbs, S.; Metreveli, Z.; Seth, K. K.; Tomaradze, A.; Ecklund, K. M.; Love, W.; Savinov, V.; Lopez, A.; Mendez, H.; Ramirez, J.; Ge, J. Y.; Miller, D. H.; Sanghi, B.; Shipsey, I. P. J.; Xin, B.; Adams, G. S.; Anderson, M.; Cummings, J. P.; Danko, I.; Hu, D.; Moziak, B.; Napolitano, J.

2008-11-01

We study exclusive χc0,1,2 decays to four-hadron final states involving two charged and two neutral hadrons: π+π-π0π0, K+K-π0π0, p pmacr π0π0, K+K-ηπ0, and K±π∓K0π0. The χc states are produced in radiative decays of 3.08×106 ψ(2S) resonance decays and observed in the CLEO detector. We also measure the largest substructure contributions to the modes π+π-π0π0 and K±π∓K0π0.

Heat Transfer Issues in Thin-Film Thermal Radiation Detectors

NASA Technical Reports Server (NTRS)

Barry, Mamadou Y.

1999-01-01

The Thermal Radiation Group at Virginia Polytechnic Institute and State University has been working closely with scientists and engineers at NASA's Langley Research Center to develop accurate analytical and numerical models suitable for designing next generation thin-film thermal radiation detectors for earth radiation budget measurement applications. The current study provides an analytical model of the notional thermal radiation detector that takes into account thermal transport phenomena, such as the contact resistance between the layers of the detector, and is suitable for use in parameter estimation. It was found that the responsivity of the detector can increase significantly due to the presence of contact resistance between the layers of the detector. Also presented is the effect of doping the thermal impedance layer of the detector with conducting particles in order to electrically link the two junctions of the detector. It was found that the responsivity and the time response of the doped detector decrease significantly in this case. The corresponding decrease of the electrical resistance of the doped thermal impedance layer is not sufficient to significantly improve the electrical performance of the detector. Finally, the "roughness effect" is shown to be unable to explain the decrease in the thermal conductivity often reported for thin-film layers.

Conceptual design of a Moving Belt Radiator (MBR) shuttle-attached experiment

NASA Technical Reports Server (NTRS)

Aguilar, Jerry L.

1990-01-01

The conceptual design of a shuttle-attached Moving Belt Radiator (MBR) experiment is presented. The MBR is an advanced radiator concept in which a rotating belt is used to radiate thermal energy to space. The experiment is developed with the primary focus being the verification of the dynamic characteristics of a rotating belt with a secondary objective of proving the thermal and sealing aspects in a reduced gravity, vacuum environment. The mechanical design, selection of the belt material and working fluid, a preliminary test plan, and program plan are presented. The strategy used for selecting the basic sizes and materials of the components are discussed. Shuttle and crew member requirements are presented with some options for increasing or decreasing the demands on the STS. An STS carrier and the criteria used in the selection process are presented. The proposed carrier for the Moving Belt Radiator experiment is the Hitchhiker-M. Safety issues are also listed with possible results. This experiment is designed so that a belt can be deployed, run at steady state conditions, run with dynamic perturbations imposed, verify the operation of the interface heat exchanger and seals, and finally be retracted into a stowed position for transport back to earth.

Status of NCRP Scientific Committee 1-23 Commentary on Guidance on Radiation Dose Limits for the Lens of the Eye.

PubMed

Dauer, Lawrence T; Ainsbury, Elizabeth A; Dynlacht, Joseph; Hoel, David; Klein, Barbara E K; Mayer, Don; Prescott, Christina R; Thornton, Raymond H; Vano, Eliseo; Woloschak, Gayle E; Flannery, Cynthia M; Goldstein, Lee E; Hamada, Nobuyuki; Tran, Phung K; Grissom, Michael P; Blakely, Eleanor A

2016-02-01

Previous National Council on Radiation Protection and Measurements (NCRP) publications have addressed the issues of risk and dose limitation in radiation protection and included guidance on specific organs and the lens of the eye. NCRP decided to prepare an updated commentary intended to enhance the previous recommendations provided in earlier reports. The NCRP Scientific Committee 1-23 (SC 1-23) is charged with preparing a commentary that will evaluate recent studies on the radiation dose response for the development of cataracts and also consider the type and severity of the cataracts as well as the dose rate; provide guidance on whether existing dose limits to the lens of the eye should be changed in the United States; and suggest research needs regarding radiation effects on and dose limits to the lens of the eye. A status of the ongoing work of SC 1-23 was presented at the Annual Meeting, "Changing Regulations and Radiation Guidance: What Does the Future Hold?" The following represents a synopsis of a few main points in the current draft commentary. It is likely that several changes will be forthcoming as SC 1-23 responds to subject matter expert review and develops a final document, expected by mid 2016.

Radiation Impact on Pharmaceutical Stability: Retrospective Data Review

NASA Technical Reports Server (NTRS)

Daniels, V. R.; Bayuse, T. M.; McGuire, K. M.; Antonsen, E. L.; Putcha, L.

2017-01-01

Historical studies performed by the JSC Pharmacotherapeutics Discipline suggest that exposure to spaceflight conditions may compromise the safety and efficacy of some medications. Follow-on studies have revealed that affected medications demonstrate reductions in active pharmaceutical ingredient (API) concentrations and altered release characteristics. It was hypothesized that the changes in API potency and release were from the medication's exposure to the harsh environmental conditions of spaceflight. Subsequent review of the spaceflight environmental control records from the time of these studies indicated that temperature and humidity levels aboard all spacecraft remained within United States Pharmacopeia (USP) recommended ranges to maintain optimal pharmaceutical stability. Therefore, space radiation was presumed to be the source of observed drug degradation. The Pharmacotherapeutics Discipline conducted a ground analog radiation experiment in 2006 at the NASA Space Radiation Laboratory (NSRL) at Brookhaven to validate this theory and to characterize the effects of high-energy radioactive particles on pharmaceutical stability. These data were never published. Recently, the Exploration Medical Capability (ExMC) Element finalized a research plan (RP) aimed at providing a safe and effective medication formulary for exploration spaceflight. As ExMC begins to design new flight and ground analog radiation studies, further analysis of the 2006 NSRL study data is essential for the characterization of the impact of radiation on medication potency and efficacy in the exploration spaceflight environment.

Radiation hardening of optical fibers and fiber sensors for space applications: recent advances

NASA Astrophysics Data System (ADS)

Girard, S.; Ouerdane, Y.; Pinsard, E.; Laurent, A.; Ladaci, A.; Robin, T.; Cadier, B.; Mescia, L.; Boukenter, A.

2017-11-01

In these ICSO proceedings, we review recent advances from our group concerning the radiation hardening of optical fiber and fiber-based sensors for space applications and compare their benefits to state-of-the-art results. We focus on the various approaches we developed to enhance the radiation tolerance of two classes of optical fibers doped with rare-earths: the erbium (Er)-doped ones and the ytterbium/erbium (Er/Yb)-doped ones. As a first approach, we work at the component level, optimizing the fiber structure and composition to reduce their intrinsically high radiation sensitivities. For the Erbium-doped fibers, this has been achieved using a new structure for the fiber that is called Hole-Assisted Carbon Coated (HACC) optical fibers whereas for the Er/Ybdoped optical fibers, their hardening was successfully achieved adding to the fiber, the Cerium element, that prevents the formation of the radiation-induced point defects responsible for the radiation induced attenuation in the infrared part of the spectrum. These fibers are used as part of more complex systems like amplifiers (Erbium-doped Fiber Amplifier, EDFA or Yb-EDFA) or source (Erbium-doped Fiber Source, EDFS or Yb- EDFS), we discuss the impact of using radiation-hardened fibers on the system radiation vulnerability and demonstrate the resistance of these systems to radiation constraints associated with today and future space missions. Finally, we will discuss another radiation hardening approach build in our group and based on a hardening-by-system strategy in which the amplifier is optimized during its elaboration for its future mission considering the radiation effects and not in-lab.

Adjoint sensitivity analysis of a tumor growth model and its application to spatiotemporal radiotherapy optimization.

PubMed

Fujarewicz, Krzysztof; Lakomiec, Krzysztof

2016-12-01

We investigate a spatial model of growth of a tumor and its sensitivity to radiotherapy. It is assumed that the radiation dose may vary in time and space, like in intensity modulated radiotherapy (IMRT). The change of the final state of the tumor depends on local differences in the radiation dose and varies with the time and the place of these local changes. This leads to the concept of a tumor's spatiotemporal sensitivity to radiation, which is a function of time and space. We show how adjoint sensitivity analysis may be applied to calculate the spatiotemporal sensitivity of the finite difference scheme resulting from the partial differential equation describing the tumor growth. We demonstrate results of this approach to the tumor proliferation, invasion and response to radiotherapy (PIRT) model and we compare the accuracy and the computational effort of the method to the simple forward finite difference sensitivity analysis. Furthermore, we use the spatiotemporal sensitivity during the gradient-based optimization of the spatiotemporal radiation protocol and present results for different parameters of the model.

Resolving the Schwarzschild singularity in both classic and quantum gravity

NASA Astrophysics Data System (ADS)

Zeng, Ding-fang

2017-04-01

The Schwarzschild singularity's resolution has key values in cracking the key mysteries related with black holes, the origin of their horizon entropy and the information missing puzzle involved in their evaporations. We provide in this work the general dynamic inner metric of collapsing stars with horizons and with non-trivial radial mass distributions. We find that static central singularities are not the final state of the system. Instead, the final state of the system is a periodically zero-cross breathing ball. Through 3+1 decomposed general relativity and its quantum formulation, we establish a functional Schrödinger equation controlling the micro-state of this breathing ball and show that, the system configuration with all the matter concentrating on the central point is not the unique eigen-energy-density solution. Using a Bohr-Sommerfield like "orbital" quantisation assumption, we show that for each black hole of horizon radius rh, there are about e rh2 / ℓpl2 allowable eigen-energy-density profiles. This naturally leads to physic interpretations for the micro-origin of horizon entropy, as well as solutions to the information missing puzzle involved in Hawking radiations.

Evaluation of Radiation Doses Due to Consumption of Contaminated Food Items and Calculation of Food Class-Specific Derived Intervention Levels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heinzelman, K M; Mansfield, W G

This document evaluates the expected radiation dose due to the consumption of several specific food classes (dairy, meat, produce, etc.) contaminated with specific radionuclides, and relates concentration levels in food to the detection abilities of typical aboratory analysis/measurement methods. The attached charts present the limiting organ dose as a function of the radionuclide concentration in a particular food class, and allow the user to compare these concentrations and doses to typical analytical detection apabilities. The expected radiation dose depends on several factors: the age of the individual; the radionuclide present in the food; the concentration of the radionuclide in themore » food; and the amount of food consumed. Food consumption rates for individuals of various ges were taken from the 1998 United States Food and Drug Administration (FDA) document, Accidental Radioactive Contamination of HUman Food and Animal Feeds: Recommendations for State and Local Agencies. In that document, the FDA defines the erived Intervention Level (DIL), which is the concentration of a particular radionuclide in food that if consumed could result in an individual receiving a radiation dose exceeding the Protection Action Guide (PAG) thresholds for intervention. This document also resents odified, food class specific DIL, which is calculated using a somewhat modified version of the FDA's procedure. This document begins with an overview of the FDA's DIL calculation, followed by a description of the food class specific DIL calculations, and finally charts of the radiation dose per radioactivity concentration for several food class/radionuclide combinations.« less

Food irradiation: after 35 years, have we made progress. A government perspective.

PubMed

Young, Alvin L

2003-01-01

The use of irradiation to improve the safety, protect the nutritional benefits, and preserve the quality of fresh and processed foods is a well established and proven technology. Over the past 35 years, the United States Government has invested in the science to confirm safety and in the technology to show application. The United States Department of Agriculture (USDA) and the Food and Drug Administration have approved sources of ionizing radiation for the treatment of foods, and their application to most meats, fruits, vegetables, and spices. Despite the value of this technology to the food industry and to the health and welfare of the public, only minimal application of this technology occurs. This underscores the importance of increasing the public's understanding of radiation risks relative to other hazards. Accordingly, in 1995, the Committee on Interagency Radiation Research and Policy Coordination of the Executive Office of the President made recommendations for the creation of a centralized National Radiation Information Center that would work closely with Federal departments and agencies in responding to public queries about radiation issues and Federal programs. This article updates a commentary published in 1996 (Young 1996). In the past six years, some progress has been made, including the establishment of a government operated Food Irradiation Information Center, and the completion of final rule making by USDA, thus permitting the safe treatment of meats and poultry. Despite these actions, little progress has been made on the public acceptance of this technology. The need for an informed public and for a better understanding of risks, i.e., risk communication, is noted.

Study of Aerothermodynamic Modeling Issues Relevant to High-Speed Sample Return Vehicles

NASA Technical Reports Server (NTRS)

Johnston, Christopher O.

2014-01-01

This paper examines the application of state-of-the-art coupled ablation and radiation simulations to highspeed sample return vehicles, such as those returning from Mars or an asteroid. A defining characteristic of these entries is that the surface recession rates and temperatures are driven by nonequilibrium convective and radiative heating through a boundary layer with significant surface blowing and ablation products. Measurements relevant to validating the simulation of these phenomena are reviewed and the Stardust entry is identified as providing the best relevant measurements. A coupled ablation and radiation flowfield analysis is presented that implements a finite-rate surface chemistry model. Comparisons between this finite-rate model and a equilibrium ablation model show that, while good agreement is seen for diffusion-limited oxidation cases, the finite-rate model predicts up to 50% lower char rates than the equilibrium model at sublimation conditions. Both the equilibrium and finite rate models predict significant negative mass flux at the surface due to sublimation of atomic carbon. A sensitivity analysis to flowfield and surface chemistry rates show that, for a sample return capsule at 10, 12, and 14 km/s, the sublimation rates for C and C3 provide the largest changes to the convective flux, radiative flux, and char rate. A parametric uncertainty analysis of the radiative heating due to radiation modeling parameters indicates uncertainties ranging from 27% at 10 km/s to 36% at 14 km/s. Applying the developed coupled analysis to the Stardust entry results in temperatures within 10% of those inferred from observations, and final recession values within 20% of measurements, which improves upon the 60% over-prediction at the stagnation point obtained through an uncoupled analysis. Emission from CN Violet is shown to be over-predicted by nearly and order-of-magnitude, which is consistent with the results of previous independent analyses. Finally, the coupled analysis is applied to a 14 km/s Earth entry representative of a Mars sample return. Although the radiative heating provides a larger fraction of the total heating, the influence of ablation and radiation on the flowfield are shown to be similar to Stardust.

Radiation fluxes at the FIFE site

NASA Technical Reports Server (NTRS)

Walter-Shea, Elizabeth A.; Blad, Blaine L.; Zara, Pedro; Vining, Roel; Hays, Cynthia J.; Mesarch, Mark A.

1993-01-01

The main objective of the International Satellite Land Surface Climatology Project (ISLSCP) has been stated as 'the development of techniques that may be applied to satellite observations of the radiation reflected and emitted from the Earth to yield quantitative information concerning land surface climatological conditions'. The major field study, FIFE (the First ISLSCP Field Experiment), was conducted in 1987-89 to accomplish this objective. Four intensive field campaigns (IFC's) were carried out in 1987 and one in 1989. Factors contributing to observed reflected radiation from the FIFE site must be understood before the radiation observed by satellites can be used to quantify surface processes. Our last report (Walter-Shea et al., 1992b) focused on slope effects on incoming and outgoing shortwave radiation and net radiation from data collected in 1989. We report here on the final analysis of the slope data as well as results from thermal radiation studies conducted during the FIFE experiment. The specific areas reported are the following: (1) analysis of slope effects on measured reflectance values and estimates of surface albedo; (2) using remotely-measured surface temperatures as a means of estimating sensible heat flux from the Konza Prairie; (3) extracting canopy temperatures from remotely-measured composite surface temperatures; (4) modeling the measured composite temperature of partially vegetated surfaces; and (5) estimating gap distribution in partially vegetated surfaces from reflectance measurements.

A new ODE tumor growth modeling based on tumor population dynamics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oroji, Amin; Omar, Mohd bin; Yarahmadian, Shantia

2015-10-22

In this paper a new mathematical model for the population of tumor growth treated by radiation is proposed. The cells dynamics population in each state and the dynamics of whole tumor population are studied. Furthermore, a new definition of tumor lifespan is presented. Finally, the effects of two main parameters, treatment parameter (q), and repair mechanism parameter (r) on tumor lifespan are probed, and it is showed that the change in treatment parameter (q) highly affects the tumor lifespan.

Final Report for DOE Grant DE-FG02-06ER64160 Retrieval of Cloud Properties and Direct Testing of Cloud and Radiation Parameterizations using ARM Observations.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Donovan, David Patrick

This report briefly summaries the work performed at KNMI under DOE Grant DE-FG02-06ER64160 which, in turn was conducted in support of DOE Grant DE-FG02-90ER61071 lead by E. Clothieux of Penn. State U. The specific work at KNMI revolved around the development and application of the EarthCARE simulator to ground-based multi-sensor simulations.

Nonadiabatic coupling reduces the activation energy in thermally activated delayed fluorescence.

PubMed

Gibson, J; Penfold, T J

2017-03-22

The temperature dependent rate of a thermally activated process is given by the Arrhenius equation. The exponential decrease in the rate with activation energy, which this imposes, strongly promotes processes with small activation barriers. This criterion is one of the most challenging during the design of thermally activated delayed fluorescence (TADF) emitters used in organic light emitting diodes. The small activation energy is usually achieved with donor-acceptor charge transfer complexes. However, this sacrifices the radiative rate and is therefore incommensurate with the high luminescence quantum yields required for applications. Herein we demonstrate that the spin-vibronic mechanism, operative for efficient TADF, overcomes this limitation. Nonadiabatic coupling between the lowest two triplet states give rise to a strong enhancement of the rate of reserve intersystem crossing via a second order mechanism and promotes population transfer between the T 1 to T 2 states. Consequently the rISC mechanism is actually operative between initial and final state exhibiting an energy gap that is smaller than between the T 1 and S 1 states. This contributes to the small activation energies for molecules exhibiting a large optical gap, identifies limitations of the present design procedures and provides a basis from which to construct TADF molecules with simultaneous high radiative and rISC rates.

Dynamics in a Maximally Symmetric Universe

NASA Astrophysics Data System (ADS)

Bewketu, Asnakew

2016-03-01

Our present understanding of the evolution of the universe relies upon the Friedmann- Robertson- Walker cosmological models. This model is so successful that it is now being considered as the Standard Model of Cosmology. So in this work we derive the Fried- mann equations using the Friedmann-Robertson-Walker metric together with Einstein field equation and then we give a simple method to reduce Friedmann equations to a second order linear differential equation when it is supplemented with a time dependent equation of state. Furthermore, as illustrative examples, we solve this equation for some specific time dependent equation of states. And also by using the Friedmann equations with some time dependent equation of state we try to determine the cosmic scale factor(the rate at which the universe expands) and age of the Friedmann universe, for the matter dominated era, radiation dominated era and for both matter and radiation dominated era by considering different cases. We have finally discussed the observable quantities that can be evidences for the accelerated expansion of the Friedmann universe. I would like to acknowledge Addis Ababa University for its financial and material support to my work on the title mentioned above.

Systematic investigation of NLTE phenomena in the limit of small departures from LTE

NASA Astrophysics Data System (ADS)

Libby, S. B.; Graziani, F. R.; More, R. M.; Kato, T.

1997-04-01

In this paper, we begin a systematic study of Non-Local Thermal Equilibrium (NLTE) phenomena in near equilibrium (LTE) high energy density, highly radiative plasmas. It is shown that the principle of minimum entropy production rate characterizes NLTE steady states for average atom rate equations in the case of small departures form LTE. With the aid of a novel hohlraum-reaction box thought experiment, we use the principles of minimum entropy production and detailed balance to derive Onsager reciprocity relations for the NLTE responses of a near equilibrium sample to non-Planckian perturbations in different frequency groups. This result is a significant symmetry constraint on the linear corrections to Kirchoff's law. We envisage applying our strategy to a number of test problems which include: the NLTE corrections to the ionization state of an ion located near the edge of an otherwise LTE medium; the effect of a monochromatic radiation field perturbation on an LTE medium; the deviation of Rydberg state populations from LTE in recombining or ionizing plasmas; multi-electron temperature models such as that of Busquet; and finally, the effect of NLTE population shifts on opacity models.

Preclinical evaluation of radiation and systemic, RGD-targeted, adeno-associated virus phage-TNF gene therapy in a mouse model of spontaneously metastatic melanoma.

PubMed

Quinn, T J; Healy, N; Sara, A; Maggi, E; Claros, C S; Kabarriti, R; Scandiuzzi, L; Liu, L; Gorecka, J; Adem, A; Basu, I; Yuan, Z; Guha, C

2017-01-01

The incidence of melanoma in the United States continues to rise, with metastatic lesions notoriously recalcitrant to therapy. There are limited effective treatment options available and a great need for more effective therapies that can be rapidly integrated in the clinic. In this study, we demonstrate that the combination of RGD-targeted adeno-associated virus phage (RGD-AAVP-TNF) with hypofractionated radiation therapy results in synergistic inhibition of primary syngeneic B16 melanoma in a C57 mouse model. Furthermore, this combination appeared to modify the tumor microenvironment, resulting in decreased Tregs in the draining LN and increased tumor-associated macrophages within the primary tumor. Finally, there appeared to be a reduction in metastatic potential and a prolongation of overall survival in the combined treatment group. These results indicate the use of targeted TNF gene therapy vector with radiation treatment could be a valuable treatment option for patients with metastatic melanoma.

Measurement of absolute hadronic branching fractions of D mesons and e+e- -->DD cross sections at Ec.m.=3773 MeV.

PubMed

He, Q; Muramatsu, H; Park, C S; Park, W; Thorndike, E H; Coan, T E; Gao, Y S; Liu, F; Artuso, M; Boulahouache, C; Blusk, S; Butt, J; Dambasuren, E; Dorjkhaidav, O; Li, J; Menaa, N; Mountain, R; Nandakumar, R; Randrianarivony, K; Redjimi, R; Sia, R; Skwarnicki, T; Stone, S; Wang, J C; Zhang, K; Csorna, S E; Bonvicini, G; Cinabro, D; Dubrovin, M; Briere, R A; Chen, G P; Chen, J; Ferguson, T; Tatishvili, G; Vogel, H; Watkins, M E; Rosner, J L; Adam, N E; Alexander, J P; Berkelman, K; Cassel, D G; Crede, V; Duboscq, J E; Ecklund, K M; Ehrlich, R; Fields, L; Gibbons, L; Gittelman, B; Gray, R; Gray, S W; Hartill, D L; Heltsley, B K; Hertz, D; Hsu, L; Jones, C D; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Mahlke-Krüger, H; Meyer, T O; Onyisi, P U E; Patterson, J R; Peterson, D; Phillips, E A; Pivarski, J; Riley, D; Ryd, A; Sadoff, A J; Schwarthoff, H; Shi, X; Shepherd, M R; Stroiney, S; Sun, W M; Urner, D; Weaver, K M; Wilksen, T; Weinberger, M; Athar, S B; Avery, P; Breva-Newell, L; Patel, R; Potlia, V; Stoeck, H; Yelton, J; Rubin, P; Cawlfield, C; Eisenstein, B I; Gollin, G D; Karliner, I; Kim, D; Lowrey, N; Naik, P; Sedlack, C; Selen, M; Williams, J; Wiss, J; Edwards, K W; Besson, D; Pedlar, T K; Cronin-Hennessy, D; Gao, K Y; Gong, D T; Hietala, J; Kubota, Y; Klein, T; Lang, B W; Li, S Z; Poling, R; Scott, A W; Smith, A; Dobbs, S; Metreveli, Z; Seth, K K; Tomaradze, A; Zweber, P; Ernst, J; Mahmood, A H; Severini, H; Asner, D M; Dytman, S A; Love, W; Mehrabyan, S; Mueller, J A; Savinov, V; Li, Z; Lopez, A; Mendez, H; Ramirez, J; Huang, G S; Miller, D H; Pavlunin, V; Sanghi, B; Shipsey, I P J; Adams, G S; Chasse, M; Cravey, M; Cummings, J P; Danko, I; Napolitano, J

2005-09-16

Using 55.8 pb(-1) of e+e- collisions recorded at the psi(3770) resonance with the CLEO-c detector at CESR, we determine absolute hadronic branching fractions of charged and neutral D mesons using a double tag technique. Among measurements for three D0 and six D+ modes, we obtain reference branching fractions B(D0-->K-pi+)=(3.91+/-0.08+/-0.09)% and B(D+-->K-pi+pi+)=(9.5+/-0.2+/-0.3)%, where the uncertainties are statistical and systematic, respectively. Final state radiation is included in these branching fractions by allowing for additional, unobserved, photons in the final state. Using a determination of the integrated luminosity, we also extract the cross sections sigma(e+e- -->D0D0)=(3.60+/-0.07(+0.07)(-0.05)) nb and sigma(e+e- -->D+D-)=(2.79+/-0.07(+0.10)(-0.04)) nb.

Proton-hole and core-excited states in the semi-magic nucleus 131In82

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taprogge, J.; Jungclaus, A.; Grawe, H.

2016-11-01

The decay of the N = 83 nucleus Cd-131 has been studied at the RIBF facility at the RIKEN Nishina Center. The main purpose of the study was to identify the position of the and proton-hole states and the energies of core-excited configurations in the semi-magic nucleus In-131. From the radiation emitted following the decay, a level scheme of In-131 was established and the feeding to each excited state determined. Similarities between the single-particle transitions observed in the decays of the N = 83 isotones In-132 and Cd-131 are discussed. Finally the excitation energies of several core-excited configurations in In-131more » are compared to QRPA and shell-model calculations.« less

Scattering amplitudes of massive Nambu-Goldstone bosons

NASA Astrophysics Data System (ADS)

Brauner, Tomáš; Jakobsen, Martin F.

2018-01-01

Massive Nambu-Goldstone (mNG) bosons are quasiparticles the gap of which is determined exactly by symmetry. They appear whenever a symmetry is broken spontaneously in the ground state of a quantum many-body system and at the same time explicitly by the system's chemical potential. In this paper, we revisit mNG bosons and show that apart from their gap symmetry also protects their scattering amplitudes. Just like for ordinary gapless Nambu-Goldstone (NG) bosons, the scattering amplitudes of mNG bosons vanish in the long-wavelength limit. Unlike for gapless NG bosons, this statement holds for any scattering process involving one or more external mNG states; there are no kinematic singularities associated with the radiation of a soft mNG boson from an on-shell initial or final state.

Some dipole shower studies

NASA Astrophysics Data System (ADS)

Cabouat, Baptiste; Sjöstrand, Torbjörn

2018-03-01

Parton showers have become a standard component in the description of high-energy collisions. Nowadays most final-state ones are of the dipole character, wherein a pair of partons branches into three, with energy and momentum preserved inside this subsystem. For initial-state showers a dipole picture is also possible and commonly used, but the older global-recoil strategy remains a valid alternative, wherein larger groups of partons share the energy-momentum preservation task. In this article we introduce and implement a dipole picture also for initial-state radiation in Pythia, and compare with the existing global-recoil one, and with data. For the case of Deeply Inelastic Scattering we can directly compare with matrix element expressions and show that the dipole picture gives a very good description over the whole phase space, at least for the first branching.

Radiation therapy facilities in the United States

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ballas, Leslie K.; Elkin, Elena B.; Schrag, Deborah

2006-11-15

Purpose: About half of all cancer patients in the United States receive radiation therapy as a part of their cancer treatment. Little is known, however, about the facilities that currently deliver external beam radiation. Our goal was to construct a comprehensive database of all radiation therapy facilities in the United States that can be used for future health services research in radiation oncology. Methods and Materials: From each state's health department we obtained a list of all facilities that have a linear accelerator or provide radiation therapy. We merged these state lists with information from the American Hospital Association (AHA),more » as well as 2 organizations that audit the accuracy of radiation machines: the Radiologic Physics Center (RPC) and Radiation Dosimetry Services (RDS). The comprehensive database included all unique facilities listed in 1 or more of the 4 sources. Results: We identified 2,246 radiation therapy facilities operating in the United States as of 2004-2005. Of these, 448 (20%) facilities were identified through state health department records alone and were not listed in any other data source. Conclusions: Determining the location of the 2,246 radiation facilities in the United States is a first step in providing important information to radiation oncologists and policymakers concerned with access to radiation therapy services, the distribution of health care resources, and the quality of cancer care.« less

Time dependent Schrödinger equation for black hole evaporation: No information loss

NASA Astrophysics Data System (ADS)

Corda, Christian

2015-02-01

In 1976 S. Hawking claimed that "Because part of the information about the state of the system is lost down the hole, the final situation is represented by a density matrix rather than a pure quantum state".1 In a series of papers, together with collaborators, we naturally interpreted BH quasi-normal modes (QNMs) in terms of quantum levels discussing a model of excited BH somewhat similar to the historical semi-classical Bohr model of the structure of a hydrogen atom. Here we explicitly write down, for the same model, a time dependent Schrödinger equation for the system composed by Hawking radiation and BH QNMs. The physical state and the correspondent wave function are written in terms of a unitary evolution matrix instead of a density matrix. Thus, the final state results to be a pure quantum state instead of a mixed one. Hence, Hawking's claim is falsified because BHs result to be well defined quantum mechanical systems, having ordered, discrete quantum spectra, which respect 't Hooft's assumption that Schrödinger equations can be used universally for all dynamics in the universe. As a consequence, information comes out in BH evaporation in terms of pure states in a unitary time dependent evolution. In Section 4 of this paper we show that the present approach permits also to solve the entanglement problem connected with the information paradox.

Formation of Triplet Positron-helium Bound State by Stripping of Positronium Atoms in Collision with Ground State Helium

NASA Technical Reports Server (NTRS)

Drachman, Richard J.

2006-01-01

Formation of triplet positron-helium bound state by stripping of positronium atoms in collision with ground state helium JOSEPH DI RlENZI, College of Notre Dame of Maryland, RICHARD J. DRACHMAN, NASA/Goddard Space Flight Center - The system consisting of a positron and a helium atom in the triplet state e(+)He(S-3)(sup e) was conjectured long ago to be stable [1]. Its stability has recently been established rigorously [2], and the values of the energies of dissociation into the ground states of Ps and He(+) have also been reported [3] and [4]. We have evaluated the cross-section for this system formed by radiative attachment of a positron in triplet He state and found it to be small [5]. The mechanism of production suggested here should result in a larger cross-section (of atomic size) which we are determining using the Born approximation with simplified initial and final wave functions.

Ground-state hyperfine splitting for Rb, Cs, Fr, Ba+, and Ra+

NASA Astrophysics Data System (ADS)

Ginges, J. S. M.; Volotka, A. V.; Fritzsche, S.

2017-12-01

We have systematically investigated the ground-state hyperfine structure for alkali-metal atoms 87Rb,133Cs, and 211Fr and alkali-metal-like ions +135Ba and +225Ra, which are of particular interest for parity violation studies. The quantum electrodynamic one-loop radiative corrections have been rigorously evaluated within an extended Furry picture employing core-Hartree and Kohn-Sham atomic potentials. Moreover, the effect of the nuclear magnetization distribution on the hyperfine structure intervals has been studied in detail and its uncertainty has been estimated. Finally, the theoretical description of the hyperfine structure has been completed with full many-body calculations performed in the all-orders correlation potential method.

Analytic calculation of 1-jettiness in DIS at O (α s)

DOE PAGES

Kang, Daekyoung; Lee, Christopher; Stewart, Iain W.

2014-11-01

We present an analytic O(α s) calculation of cross sections in deep inelastic scattering (DIS) dependent on an event shape, 1-jettiness, that probes final states with one jet plus initial state radiation. This is the first entirely analytic calculation for a DIS event shape cross section at this order. We present results for the differential and cumulative 1-jettiness cross sections, and express both in terms of structure functions dependent not only on the usual DIS variables x, Q 2 but also on the 1-jettiness τ. Combined with previous results for log resummation, predictions are obtained over the entire range ofmore » the 1-jettiness distribution.« less

Multi-Dimensional, Non-Pyrolyzing Ablation Test Problems

NASA Technical Reports Server (NTRS)

Risch, Tim; Kostyk, Chris

2016-01-01

Non-pyrolyzingcarbonaceous materials represent a class of candidate material for hypersonic vehicle components providing both structural and thermal protection system capabilities. Two problems relevant to this technology are presented. The first considers the one-dimensional ablation of a carbon material subject to convective heating. The second considers two-dimensional conduction in a rectangular block subject to radiative heating. Surface thermochemistry for both problems includes finite-rate surface kinetics at low temperatures, diffusion limited ablation at intermediate temperatures, and vaporization at high temperatures. The first problem requires the solution of both the steady-state thermal profile with respect to the ablating surface and the transient thermal history for a one-dimensional ablating planar slab with temperature-dependent material properties. The slab front face is convectively heated and also reradiates to a room temperature environment. The back face is adiabatic. The steady-state temperature profile and steady-state mass loss rate should be predicted. Time-dependent front and back face temperature, surface recession and recession rate along with the final temperature profile should be predicted for the time-dependent solution. The second problem requires the solution for the transient temperature history for an ablating, two-dimensional rectangular solid with anisotropic, temperature-dependent thermal properties. The front face is radiatively heated, convectively cooled, and also reradiates to a room temperature environment. The back face and sidewalls are adiabatic. The solution should include the following 9 items: final surface recession profile, time-dependent temperature history of both the front face and back face at both the centerline and sidewall, as well as the time-dependent surface recession and recession rate on the front face at both the centerline and sidewall. The results of the problems from all submitters will be collected, summarized, and presented at a later conference.

Radiation damage and waste management options for the SOMBRERO final focus system and neutron dumps

DOE Office of Scientific and Technical Information (OSTI.GOV)

Latkowski, J F; Meier, W R; Reyes, S

1999-08-09

Previous studies of the safety and environmental aspects of the SOMBRERO inertial fusion energy (IFE) power plant design did not completely address the issues associated with the final focus system. While past work calculated neutron fluences for a grazing incidence metal mirror (GIMM) and a final focus mirror, scattering off of the final optical component was not included, and thus, fluences in the final focus mirror were significantly underestimated. In addition, past work did not consider neutron-induced gamma-rays. Finally, power plant lifetime waste volumes may have been underestimated as neutron activation of the neutron dumps and building structure were notmore » addressed. In the present work, a modified version of the SOMBRERO target building is presented where a significantly larger open solid-angle fraction (5%) is used to enhance beam smoothing of a diode-pumped solid-state laser (DPSSL). The GIMMs are replaced with transmissive fused silica wedges and have been included in three -dimensional neutron and photon transport calculations. This work shows that a power plant with a large open solid-angle fraction, needed for beam smoothing with a DPSSL, is acceptable from tritium breeding, and neutron activation points-of-view.« less

Review and state of the art on radiation sterilization of medical devices

NASA Astrophysics Data System (ADS)

Dorpema, J. W.

Review and state of art of radiation sterilization Radiation as a sterilization method was designed in the years 1950-1960. The decade afterwards the application for sterilization of medical products and devices was developped. Extensive studies performed on both the physical, chemical and (micro) biological aspects revealed the requirements for safety and efficacy. These efforts were highly stimulated by the IAEA and resulted in a elegant sterilization method. In product manufacturing, where sterilization represents a final step in the production sequence, radiation has eversince reached its widest application in the field of medical devices. As a spin off it initiated new ideas and approaches towards sterilization in general. Consequently sterility was redefined in terms of a probabilistic concept (10-6) and the bioburden determination method was introduced as a tool for both quality control and potential instrument for dose setting. However these refinements also created controversies, whereby the dose requirements became divided for Europe and North America. Moreover studies recently performed in Europe suggest even a further extension of this opinion gap. Detailed studies, on the clinical effects of low dose treated products (12.5 - 17.5 kGy) are needed to counterbalance the dose suggestions extracted from statistically based dose determinations (> 28 kGy ) and the microbiological resistance determinations ( > 28 - 30 kGy). Dose setting based on risk classification could be considered for distinct product categories. In the mean time a general acceptance of the originally, in the early seventhies, established minimum dose of 25 kGy would seem a reasonable compromise. As the interest for radiation sterilization as the favourable, non polluting and simple method is increasing rapidly over the last five years, both gamma- and beta driven sterilization plants will be needed. Harmonization on sterilization dose therfore requires high priority.

Application of Radiation Chemistry to Some Selected Technological Issues Related to the Development of Nuclear Energy.

PubMed

Bobrowski, Krzysztof; Skotnicki, Konrad; Szreder, Tomasz

2016-10-01

The most important contributions of radiation chemistry to some selected technological issues related to water-cooled reactors, reprocessing of spent nuclear fuel and high-level radioactive wastes, and fuel evolution during final radioactive waste disposal are highlighted. Chemical reactions occurring at the operating temperatures and pressures of reactors and involving primary transients and stable products from water radiolysis are presented and discussed in terms of the kinetic parameters and radiation chemical yields. The knowledge of these parameters is essential since they serve as input data to the models of water radiolysis in the primary loop of light water reactors and super critical water reactors. Selected features of water radiolysis in heterogeneous systems, such as aqueous nanoparticle suspensions and slurries, ceramic oxides surfaces, nanoporous, and cement-based materials, are discussed. They are of particular concern in the primary cooling loops in nuclear reactors and long-term storage of nuclear waste in geological repositories. This also includes radiation-induced processes related to corrosion of cladding materials and copper-coated iron canisters, dissolution of spent nuclear fuel, and changes of bentonite clays properties. Radiation-induced processes affecting stability of solvents and solvent extraction ligands as well oxidation states of actinide metal ions during recycling of the spent nuclear fuel are also briefly summarized.

Grade Inflation in Medical Student Radiation Oncology Clerkships: Missed Opportunities for Feedback?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grover, Surbhi, E-mail: surbhi.grover@uphs.upenn.edu; Swisher-McClure, Samuel; Sosnowicz, Stasha

Purpose: To test the hypothesis that medical student radiation oncology elective rotation grades are inflated and cannot be used to distinguish residency applicants. Methods and Materials: The records of 196 applicants to a single radiation oncology residency program in 2011 and 2012 were retrospectively reviewed. The grades for each rotation in radiation oncology were collected and converted to a standardized 4-point grading scale (honors, high pass, pass, fail). Pass/fail grades were scored as not applicable. The primary study endpoint was to compare the distribution of applicants' grades in radiation oncology with their grades in medicine, surgery, pediatrics, and obstetrics/gynecology core clerkships.more » Results: The mean United States Medical Licensing Examination Step 1 score of the applicants was 237 (range, 188-269), 43% had additional Masters or PhD degrees, and 74% had at least 1 publication. Twenty-nine applicants were graded for radiation oncology rotations on a pass/fail basis and were excluded from the final analysis. Of the remaining applicants (n=167), 80% received the highest possible grade for their radiation oncology rotations. Grades in radiation oncology were significantly higher than each of the other 4 clerkships studied (P<.001). Of all applicants, 195 of 196 matched into a radiation oncology residency. Higher grades in radiation oncology were associated with significantly higher grades in the pediatrics core clerkship (P=.002). However, other medical school performance metrics were not significantly associated with higher grades in radiation oncology. Conclusions: Although our study group consists of a selected group of radiation oncology applicants, their grades in radiation oncology clerkships were highly skewed toward the highest grades when compared with grades in other core clerkships. Student grading in radiation oncology clerkships should be re-evaluated to incorporate more objective and detailed performance metrics to allow for meaningful feedback to trainees and to better evaluate residency applicants to radiation oncology.« less

High-statistics study of the reaction γp → p2π0

NASA Astrophysics Data System (ADS)

Sokhoyan, V.; Gutz, E.; Crede, V.; van Pee, H.; Anisovich, A. V.; Bacelar, J. C. S.; Bantes, B.; Bartholomy, O.; Bayadilov, D.; Beck, R.; Beloglazov, Y. A.; Castelijns, R.; Dutz, H.; Elsner, D.; Ewald, R.; Frommberger, F.; Fuchs, M.; Funke, Ch.; Gregor, R.; Gridnev, A. B.; Hillert, W.; Hoffmeister, Ph.; Horn, I.; Jaegle, I.; Junkersfeld, J.; Kalinowsky, H.; Kammer, S.; Kleber, V.; Klein, Frank; Klein, Friedrich; Klempt, E.; Kotulla, M.; Krusche, B.; Lang, M.; Löhner, H.; Lopatin, I. V.; Lugert, S.; Mertens, T.; Messchendorp, J. G.; Metag, V.; Metsch, B.; Nanova, M.; Nikonov, V. A.; Novinsky, D.; Novotny, R.; Ostrick, M.; Pant, L.; Pfeiffer, M.; Piontek, D.; Roy, A.; Sarantsev, A. V.; Schmidt, Ch.; Schmieden, H.; Seifen, T.; Shende, S.; Süle, A.; Sumachev, V. V.; Szczepanek, T.; Thiel, A.; Thoma, U.; Trnka, D.; Varma, R.; Walther, D.; Wendel, Ch.; Wilson, A.

2015-08-01

The photoproduction of 2 π 0 mesons off protons was studied with the Crystal Barrel/TAPS experiment at the electron accelerator ELSA in Bonn. The energy of photons produced in a radiator was tagged in the energy range from 600 MeV to 2.5 GeV. Differential and total cross sections and pπ 0 π 0 Dalitz plots are presented. Part of the data was taken with a diamond radiator producing linearly polarized photons, and beam asymmetries were derived. Properties of nucleon and Δ resonances contributing to the pπ 0 π 0 final state were determined within the Bonn-Gatchina (BnGa) partial-wave analysis. The data presented here allow us to determine branching ratios of nucleon and Δ resonances for their decays into pπ 0 π 0 via several intermediate states. Most prominent are decays proceeding via Δ(1232) π, N(1440)1/2+ π, N(1520)3/2- π, N(1680)5/2+ π, but also pf 0(500), pf 0(980), and pf 2(1270) contribute to the reaction.

MO-C-18C-01: Radiation Risks at Level of Few CT Scans: How Real?- Science to Practice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rehani, M; Samei, E; Morgan, W

2014-06-15

There are controversies surrounding radiation effects in human population in the range of radiation doses encountered by patients resulting from one to several CT scans. While it is understandable why the effects from low levels of diagnostic radiation are controversial, the situation is complicated by the media which may distort the known facts. There is need to understand the state of science regarding low-level radiation effects and also to understand how to communicate the potential risk with patients, the public and media. This session will seek to come to a consensus in order to speak with one voice to themore » media and the public. This session will review radiation effects known so far from a variety of exposed groups since the nuclear holocaust, provide clarification where effects are certain and where they are not, at what level extrapolation is the only way and at what level there is weak but agreeable acceptance. We will depict where and why there is agreement among organizations responsible for studying radiation effects, and how to deal with situations where effects are uncertain. Specific focus on radiation effects in children will be provided.Finally, the session will attempt to bridge the communication gap from the science to how to be an effective communicator with patients, parents, and media about ionizing radiation. Learning Objectives: To have a clear understanding about certainties and uncertainties of radiation effects at the level of a few CT scans To understand the results and limitations from 3 major pediatric CT scientific studies on childhood exposures published recently. To understand successful strategies used in risk communication.« less

Erratum: ``The Effects of Metallicity and Grain Size on Gravitational Instabilities in Protoplanetary Disks'' (ApJ 636, L149 [2006])

NASA Astrophysics Data System (ADS)

Cai, Kai; Durisen, Richard H.; Michael, Scott; Boley, Aaron C.; Mejía, Annie C.; Pickett, Megan K.; D'Alessio, Paola

2006-05-01

We have found that the total cumulative radiative energy losses shown in Figure 2 of the above-mentioned Letter were computed for only half the disk. This caused the final global cooling times tcool in the eighth column of the original Table 1 to be too large by a factor of 2. Proper values of tcool are given in the revised Table 1 below. To be more consistent with what the Letter states, we now use instantaneous values for both the total internal energy and the final total net cooling rates to compute final tcool's, instead of averaging the loss rates over an interval of time at the end of the calculations before dividing, as was done in the Letter. We also take this opportunity to make a few other inconsequential corrections to the fourth column of the table. In addition to the changes to Table 1, the approximate initial tcool relation in the fourth paragraph of § 3.2 becomes tcool~Z/Zsolar to within tens of percent. Despite the corrections, our conclusions in the Letter remain unchanged. Most importantly, the final tcool's vary with metallicity and are still too long for disk fragmentation to occur with our equation of state over the range of Z examined. We regret any inconvenience our errors may have caused.

Dental management for head and neck cancer patients undergoing radiation therapy: comprehensive patient based planning--a case report.

PubMed

Higham, Paola; Quek, Samuel; Cohen, Harold V

2009-01-01

Medical management of the head and neck cancer patient (HNCP) most often will include radiation therapy to the head and neck region. HNCPs with malignant disease require judicious dental treatment planning prior to radiation therapy (RT) and/or chemotherapy. RT can result in a multitude of adverse effects, both reversible and irreversible. We report a case of a patient with squamous cell carcinoma of the throat above the larynx (supraglottic), who did not adhere to dental treatment recommendations for both pre- and post radiation dental management. The focus of this case report is to create awareness within the clinician that, in addition to evaluating the patient for the disease related issues that may affect the oral cavity and dentition, a total management plan should include factors beyond the structural oral problems related to the cancer. Final treatment plans for the HNCP should include medical assessment of past dental history, oral hygiene, potential compliance, or lack of, to dental care recommendations, the emotional state of the patient, socio-economic status of the patient (lifestyle, cost of care), future quality of life, the medical and/or life prognosis of the patient.

Effects of caffeine on radiation-induced phenomena associated with cell- cycle traverse of mammalian cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Walters, R.A.; Gurley, L.R.; Tobby, R.A.

1974-02-01

Caffeine induced a state of G/sub 1/ arrest when added to an exponentially growing culture of Chinese hamster cells (line CHO). In addition to its effect on cell-cycle traverse, caffeine ameliorated a number of the responses of cells to ionizing radiation. The duration of the division delay period following x-irradiation of caffeine-treated cells was reduced, and the magnitude of reduction was dependent on caffeine concentration. Cells irradiated during the DNA synthetic phase in the presence of caffeine were delayed less in their exit from S, measured autoradiographically, and the radiation-induced reduction of radioactive thymidine incorporation into DNA was lessened. Cellsmore » synchronized by isoleucine deprivation, while being generally less sensitive to the effects of ionizing radiation than mitotically synchronized cells, were equally responsive to the effects of caffeine. The x-rayinduced reduction of phosphorylation of lysine-rich histone F1 was less in caffeine-treated cells than in untreated cells. Finally, survival after irradiation was only slightly reduced in caffeinetreated cells. A possible role of cyclic AMP in cell-cycle traverse of irradiated cells is discussed. (auth)« less

A factorization approach to next-to-leading-power threshold logarithms

NASA Astrophysics Data System (ADS)

Bonocore, D.; Laenen, E.; Magnea, L.; Melville, S.; Vernazza, L.; White, C. D.

2015-06-01

Threshold logarithms become dominant in partonic cross sections when the selected final state forces gluon radiation to be soft or collinear. Such radiation factorizes at the level of scattering amplitudes, and this leads to the resummation of threshold logarithms which appear at leading power in the threshold variable. In this paper, we consider the extension of this factorization to include effects suppressed by a single power of the threshold variable. Building upon the Low-Burnett-Kroll-Del Duca (LBKD) theorem, we propose a decomposition of radiative amplitudes into universal building blocks, which contain all effects ultimately responsible for next-to-leading-power (NLP) threshold logarithms in hadronic cross sections for electroweak annihilation processes. In particular, we provide a NLO evaluation of the radiative jet function, responsible for the interference of next-to-soft and collinear effects in these cross sections. As a test, using our expression for the amplitude, we reproduce all abelian-like NLP threshold logarithms in the NNLO Drell-Yan cross section, including the interplay of real and virtual emissions. Our results are a significant step towards developing a generally applicable resummation formalism for NLP threshold effects, and illustrate the breakdown of next-to-soft theorems for gauge theory amplitudes at loop level.

Hadron molecules

NASA Astrophysics Data System (ADS)

Thomas, Gutsche; Tanja, Branz; Amand, Faessler; Ian, Woo Lee; Valery, E. Lyubovitskij

2010-09-01

We discuss a possible interpretation of the open charm mesons D*s0(2317), Ds1(2460) and the hidden charm mesons X(3872), Y(3940) and Y(4140) as hadron molecules. Using a phenomenological Lagrangian approach we review the strong and radiative decays of the D*s0(2317) and Ds1(2460) states. The X(3872) is assumed to consist dominantly of molecular hadronic components with an additional small admixture of a charmonium configuration. Determing the radiative (γJ/Ψ and γΨ(2s)) and strong (J/Ψ2π and J/Ψ3π) decay modes we show that the present experimental observation is consistent with the molecular structure assumption of the X(3872). Finally, we give evidence for molecular interpretations of the Y(3940) and Y(4140) related to the observed strong decay modes J/Ψ + ω or J/Ψ + varphi, respectively.

Association of Radon Background and Total Background Ionizing Radiation with Alzheimer's Disease Deaths in U.S. States.

PubMed

Lehrer, Steven; Rheinstein, Peter H; Rosenzweig, Kenneth E

2017-01-01

Exposure of the brain to ionizing radiation might promote the development of Alzheimer's disease (AD). Analysis of AD death rates versus radon background radiation and total background radiation in U.S. states. Total background, radon background, cosmic and terrestrial background radiation measurements are from Assessment of Variations in Radiation Exposure in the United States and Report No. 160 - Ionizing Radiation Exposure of the Population of the United States. 2013 AD death rates by U.S. state are from the Alzheimer's Association. Radon background ionizing radiation was significantly correlated with AD death rate in 50 states and the District of Columbia (r = 0.467, p = 0.001). Total background ionizing radiation was also significantly correlated with AD death rate in 50 states and the District of Columbia (r = 0.452, p = 0.001). Multivariate linear regression weighted by state population demonstrated that AD death rate was significantly correlated with radon background (β= 0.169, p < 0.001), age (β= 0.231, p < 0.001), hypertension (β= 0.155, p < 0.001), and diabetes (β= 0.353, p < 0.001). Our findings, like other studies, suggest that ionizing radiation is a risk factor for AD. Intranasal inhalation of radon gas could subject the rhinencephalon and hippocampus to damaging radiation that initiates AD. The damage would accumulate over time, causing age to be a powerful risk factor.

A Reduced-order NLTE Kinetic Model for Radiating Plasmas of Outer Envelopes of Stellar Atmospheres

DOE Office of Scientific and Technical Information (OSTI.GOV)

Munafò, Alessandro; Mansour, Nagi N.; Panesi, Marco, E-mail: munafo@illinois.edu, E-mail: nagi.n.mansour@nasa.gov, E-mail: m.panesi@illinois.edu

The present work proposes a self-consistent reduced-order NLTE kinetic model for radiating plasmas found in the outer layers of stellar atmospheres. A detailed collisional-radiative kinetic mechanism is constructed by leveraging the most up-to-date set of ab initio and experimental data available in the literature. This constitutes the starting point for the derivation of a reduced-order model, obtained by lumping the bound energy states into groups. In order to determine the needed thermo-physical group properties, uniform and Maxwell–Boltzmann energy distributions are used to reconstruct the energy population of each group. Finally, the reduced set of governing equations for the material gasmore » and the radiation field is obtained based on the moment method. Applications consider the steady flow across a shock wave in partially ionized hydrogen. The results clearly demonstrate that adopting a Maxwell–Boltzmann grouping allows, on the one hand, for a substantial reduction of the number of unknowns and, on the other, to maintain accuracy for both gas and radiation quantities. Also, it is observed that, when neglecting line radiation, the use of two groups already leads to a very accurate resolution of the photo-ionization precursor, internal relaxation, and radiative cooling regions. The inclusion of line radiation requires adopting just one additional group to account for optically thin losses in the α , β , and γ lines of the Balmer and Paschen series. This trend has been observed for a wide range of shock wave velocities.« less

QED theory of multiphoton transitions in atoms and ions

NASA Astrophysics Data System (ADS)

Zalialiutdinov, Timur A.; Solovyev, Dmitry A.; Labzowsky, Leonti N.; Plunien, Günter

2018-03-01

This review surveys the quantum theory of electromagnetic radiation for atomic systems. In particular, a review of current theoretical studies of multiphoton processes in one and two-electron atoms and highly charged ions is provided. Grounded on the quantum electrodynamics description the multiphoton transitions in presence of cascades, spin-statistic behaviour of equivalent photons and influence of external electric fields on multiphoton in atoms and anti-atoms are discussed. Finally, the nonresonant corrections which define the validity of the concept of the excited state energy levels are introduced.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dulat, Falko; Lionetti, Simone; Mistlberger, Bernhard

We present an analytic computation of the Higgs production cross section in the gluon fusion channel, which is differential in the components of the Higgs momentum and inclusive in the associated partonic radiation through NNLO in perturbative QCD. Our computation includes the necessary higher order terms in the dimensional regulator beyond the finite part that are required for renormalisation and collinear factorisation at N 3LO. We outline in detail the computational methods which we employ. We present numerical predictions for realistic final state observables, specifically distributions for the decay products of the Higgs boson in the γγ decay channel.

Andreev reflections and the quantum physics of black holes

NASA Astrophysics Data System (ADS)

Manikandan, Sreenath K.; Jordan, Andrew N.

2017-12-01

We establish an analogy between superconductor-metal interfaces and the quantum physics of a black hole, using the proximity effect. We show that the metal-superconductor interface can be thought of as an event horizon and Andreev reflection from the interface is analogous to the Hawking radiation in black holes. We describe quantum information transfer in Andreev reflection with a final state projection model similar to the Horowitz-Maldacena model for black hole evaporation. We also propose the Andreev reflection analogue of Hayden and Preskill's description of a black hole final state, where the black hole is described as an information mirror. The analogy between crossed Andreev reflections and Einstein-Rosen bridges is discussed: our proposal gives a precise mechanism for the apparent loss of quantum information in a black hole by the process of nonlocal Andreev reflection, transferring the quantum information through a wormhole and into another universe. Given these established connections, we conjecture that the final quantum state of a black hole is exactly the same as the ground state wave function of the superconductor/superfluid in the Bardeen-Cooper-Schrieffer (BCS) theory of superconductivity; in particular, the infalling matter and the infalling Hawking quanta, described in the Horowitz-Maldacena model, forms a Cooper pairlike singlet state inside the black hole. A black hole evaporating and shrinking in size can be thought of as the analogue of Andreev reflection by a hole where the superconductor loses a Cooper pair. Our model does not suffer from the black hole information problem since Andreev reflection is unitary. We also relate the thermodynamic properties of a black hole to that of a superconductor, and propose an experiment which can demonstrate the negative specific heat feature of black holes in a growing/evaporating condensate.

How the Hawking radiation affect quantum Fisher information of Dirac particles in the background of a Schwarzschild black hole

NASA Astrophysics Data System (ADS)

Huang, ChunYu; Ma, Wen-chao; Wang, Dong; Ye, Liu

2018-01-01

In this work, the effect of Hawking radiation on the quantum Fisher information (QFI) of Dirac particles is investigated in the background of a Schwarzschild black hole. Interestingly, it has been verified that the QFI with respect to the weight parameter θ of a target state is always independent of the Hawking temperature T. This implies that if we encode the information on the weight parameter, then we can affirm that the corresponding accuracy of the parameter estimation will be immune to the Hawking effect. Besides, it reveals that the QFI with respect to the phase parameter φ exhibits a decay behavior with the increase in the Hawking temperature T and converges to a nonzero value in the limit of infinite Hawking temperature T. Remarkably, it turns out that the function F_φ on θ =π \\big /4 symmetry was broken by the influence of the Hawking radiation. Finally, we generalize the case of a three-qubit system to a case of a N-qubit system, i.e., |ψ > _{1,2,3,\\ldots ,N} =(cos θ | 0 > ^{⊗ N}+sin θ e^{iφ }| 1 > ^{⊗ N}) and obtain an interesting result: the number of particles in the initial state does not affect the QFI F_θ , nor the QFI F_φ . However, with the increasing number of particles located near the event horizon, F_φ will be affected by Hawking radiation to a large extent, while F_θ is still free from disturbance resulting from the Hawking effects.

Coherent and radiative couplings through two-dimensional structured environments

NASA Astrophysics Data System (ADS)

Galve, F.; Zambrini, R.

2018-03-01

We study coherent and radiative interactions induced among two or more quantum units by coupling them to two-dimensional (2D) lattices acting as structured environments. This model can be representative of atoms trapped near photonic crystal slabs, trapped ions in Coulomb crystals, or to surface acoustic waves on piezoelectric materials, cold atoms on state-dependent optical lattices, or even circuit QED architectures, to name a few. We compare coherent and radiative contributions for the isotropic and directional regimes of emission into the lattice, for infinite and finite lattices, highlighting their differences and existing pitfalls, e.g., related to long-time or large-lattice limits. We relate the phenomenon of directionality of emission with linear-shaped isofrequency manifolds in the dispersion relation, showing a simple way to disrupt it. For finite lattices, we study further details such as the scaling of resonant number of lattice modes for the isotropic and directional regimes, and relate this behavior with known van Hove singularities in the infinite lattice limit. Furthermore, we export the understanding of emission dynamics with the decay of entanglement for two quantum, atomic or bosonic, units coupled to the 2D lattice. We analyze in some detail completely subradiant configurations of more than two atoms, which can occur in the finite lattice scenario, in contrast with the infinite lattice case. Finally, we demonstrate that induced coherent interactions for dark states are zero for the finite lattice.

Effect of multiphase radiation on coal combustion in a pulverized coal jet flame

NASA Astrophysics Data System (ADS)

Wu, Bifen; Roy, Somesh P.; Zhao, Xinyu; Modest, Michael F.

2017-08-01

The accurate modeling of coal combustion requires detailed radiative heat transfer models for both gaseous combustion products and solid coal particles. A multiphase Monte Carlo ray tracing (MCRT) radiation solver is developed in this work to simulate a laboratory-scale pulverized coal flame. The MCRT solver considers radiative interactions between coal particles and three major combustion products (CO2, H2O, and CO). A line-by-line spectral database for the gas phase and a size-dependent nongray correlation for the solid phase are employed to account for the nongray effects. The flame structure is significantly altered by considering nongray radiation and the lift-off height of the flame increases by approximately 35%, compared to the simulation without radiation. Radiation is also found to affect the evolution of coal particles considerably as it takes over as the dominant mode of heat transfer for medium-to-large coal particles downstream of the flame. To investigate the respective effects of spectral models for the gas and solid phases, a Planck-mean-based gray gas model and a size-independent gray particle model are applied in a frozen-field analysis of a steady-state snapshot of the flame. The gray gas approximation considerably underestimates the radiative source terms for both the gas phase and the solid phase. The gray coal approximation also leads to under-prediction of the particle emission and absorption. However, the level of under-prediction is not as significant as that resulting from the employment of the gray gas model. Finally, the effect of the spectral property of ash on radiation is also investigated and found to be insignificant for the present target flame.

Occupational radiation Exposure at Agreement State-Licensed Materials Facilities, 1997-2010

DOE Office of Scientific and Technical Information (OSTI.GOV)

U.S. Nuclear Regulatory Commission, Office of Nuclear Regulatory Research

The purpose of this report is to examine occupational radiation exposures received under Agreement State licensees. As such, this report reflects the occupational radiation exposure data contained in the Radiation Exposure Information and Reporting System (REIRS) database, for 1997 through 2010, from Agreement State-licensed materials facilities.

Bismuth interstitial impurities and the optical properties of GaP 1- x - yBi xN y

DOE Office of Scientific and Technical Information (OSTI.GOV)

Christian, Theresa M.; Beaton, Daniel A.; Perkins, John D.

Two distinctive regimes of behavior are observed from GaP 1-x-y Bi x N y alloys with x < 2.4%, y < 3.4% grown by molecular beam epitaxy. These regimes are correlated with abundant bismuth interstitial impurities that are encouraged or suppressed according to the sample growth temperature, with up to 55% of incorporated bismuth located interstitially. When bismuth interstitials are present, radiative recombination arises at near-band-edge localized states rather than from impurity bands and deep state luminescence. Finally, this change demonstrates a novel strategy for controlling luminescence in isoelectronic semiconductor alloys and is attributed to a disruption of carrier transfermore » processes.« less

Bismuth interstitial impurities and the optical properties of GaP 1- x - yBi xN y

DOE PAGES

Christian, Theresa M.; Beaton, Daniel A.; Perkins, John D.; ...

2017-10-10

Two distinctive regimes of behavior are observed from GaP 1-x-y Bi x N y alloys with x < 2.4%, y < 3.4% grown by molecular beam epitaxy. These regimes are correlated with abundant bismuth interstitial impurities that are encouraged or suppressed according to the sample growth temperature, with up to 55% of incorporated bismuth located interstitially. When bismuth interstitials are present, radiative recombination arises at near-band-edge localized states rather than from impurity bands and deep state luminescence. Finally, this change demonstrates a novel strategy for controlling luminescence in isoelectronic semiconductor alloys and is attributed to a disruption of carrier transfermore » processes.« less

A Mathematica package for calculation of planar channeling radiation spectra of relativistic electrons channeled in a diamond-structure single crystal (quantum approach)

NASA Astrophysics Data System (ADS)

Azadegan, B.

2013-03-01

The presented Mathematica code is an efficient tool for simulation of planar channeling radiation spectra of relativistic electrons channeled along major crystallographic planes of a diamond-structure single crystal. The program is based on the quantum theory of channeling radiation which has been successfully applied to study planar channeling at electron energies between 10 and 100 MeV. Continuum potentials for different planes of diamond, silicon and germanium single crystals are calculated using the Doyle-Turner approximation to the atomic scattering factor and taking thermal vibrations of the crystal atoms into account. Numerical methods are applied to solve the one-dimensional Schrödinger equation. The code is designed to calculate the electron wave functions, transverse electron states in the planar continuum potential, transition energies, line widths of channeling radiation and depth dependencies of the population of quantum states. Finally the spectral distribution of spontaneously emitted channeling radiation is obtained. The simulation of radiation spectra considerably facilitates the interpretation of experimental data. Catalog identifier: AEOH_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEOH_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 446 No. of bytes in distributed program, including test data, etc.: 209805 Distribution format: tar.gz Programming language: Mathematica. Computer: Platforms on which Mathematica is available. Operating system: Operating systems on which Mathematica is available. RAM: 1 MB Classification: 7.10. Nature of problem: Planar channeling radiation is emitted by relativistic charged particles during traversing a single crystal in direction parallel to a crystallographic plane. Channeling is modeled as the motion of charged particles in a continuous planar potential which is formed by the spatially and thermally averaged action of the individual electrostatic potentials of the crystal atoms of the corresponding plane. Classically, the motion of channeled particles through the crystal resembles transverse oscillations being the source of radiation emission. For electrons of energy less than 100 MeV considered here, planar channeling has to be treated quantum mechanically by a one-dimensional Schrödinger equation for the transverse motion. Hence, this motion of the channeled electrons is restricted to a number of discrete (bound) channeling states in the planar continuum potential, and the emission of channeling radiation is caused by spontaneous electron transitions between these eigenstates. Due to relativistic and Doppler effects, the energy of the emitted photons directed into a narrow forward cone is typically shifted up by about three to five orders of magnitude. Consequently, the observed energy spectrum of channeling radiation is characterized by a number of radiation lines in the energy domain of hard X-rays. Channeling radiation may, therefore, be applied as an intense, tunable, quasi-monochromatic X-ray source. Solution method: The problem consists in finding the electron wave function for the planar continuum potential. Both the wave functions and corresponding energies of channeling states solve the Schrödinger equation of transverse electron motion. In the framework of the so-called many-beam formalism, solving the Schrödinger equation reduces to a eigenvector-eigenvalue problem of a Hermitian matrix. For that the program employs the mathematical tools allocated in the commercial computation software Mathematica. The electric field of the atomic planes in the crystal forces dipole oscillations of the channeled charged particles. In the quantum mechanical approach, the dipole approximation is also valid for spontaneous transitions between bound states. The transition strength for dedicated states depends on the magnitude of the corresponding dipole matrix element. The photon energy correlates with the particle energy, and the spectral width of radiation lines is a function of the life times of the channeling states. Running time: The program has been tested on a PC AMD Athlon X2 245 processor 2.9 GHz with 2 GB RAM. Depending on electron energy and crystal thickness, the running time of the program amounts to 5-10 min.

State-level emergency preparedness and response capabilities.

PubMed

Watkins, Sharon M; Perrotta, Dennis M; Stanbury, Martha; Heumann, Michael; Anderson, Henry; Simms, Erin; Huang, Monica

2011-03-01

Prior assessments of public health readiness had identified gaps in radiation preparedness. In recent years, preparedness planning has involved an "all-hazards" approach. Current assessment of the national status related to radiation public health emergency preparedness capabilities at the state and local health department levels was needed. A survey of state health departments related to radiation readiness was undertaken in 2010 by the Council of State and Territorial Epidemiologists (CSTE). States with nuclear power plants were instructed to consider their responses exclusive of capabilities and resources related to the plants given that the emergency response plans for nuclear power plants are specific and unique. Thirty-eight (76%) state health departments responded to the survey, including 26 of the 31 states with nuclear power plants. Specific strengths noted at the state level included that the majority of states had a written radiation response plan and most plans include a detailed section for communications issues during a radiation emergency. In addition, more than half of the states indicated that their relationship with federal partners is sufficient to provide resources for radiation emergencies, indicating the importance states placed on federal resources and expertise. Specific weaknesses are discussed and include that most states had completed little to no planning for public health surveillance to assess potential human health impacts of a radiation event; less than half had written plans to address exposure assessment, environmental sampling, human specimen collection and analysis, and human health assessment. Few reported having sufficient resources to do public health surveillance, radiation exposure assessment, laboratory functions and other capabilities. Levels of planning, resources and partnerships varied among states, those with nuclear power plants were better prepared. Gaps were evident in all states; however and additional training and resources are needed to ensure adequate levels of preparedness. Overall results of this assessment indicate that in most measures of public health capacity and capability, states are poorly prepared to adequately respond to a major radiation emergency event. Specific recommendations are noted in the discussion.

Radiative-convective equilibrium model intercomparison project

NASA Astrophysics Data System (ADS)

Wing, Allison A.; Reed, Kevin A.; Satoh, Masaki; Stevens, Bjorn; Bony, Sandrine; Ohno, Tomoki

2018-03-01

RCEMIP, an intercomparison of multiple types of models configured in radiative-convective equilibrium (RCE), is proposed. RCE is an idealization of the climate system in which there is a balance between radiative cooling of the atmosphere and heating by convection. The scientific objectives of RCEMIP are three-fold. First, clouds and climate sensitivity will be investigated in the RCE setting. This includes determining how cloud fraction changes with warming and the role of self-aggregation of convection in climate sensitivity. Second, RCEMIP will quantify the dependence of the degree of convective aggregation and tropical circulation regimes on temperature. Finally, by providing a common baseline, RCEMIP will allow the robustness of the RCE state across the spectrum of models to be assessed, which is essential for interpreting the results found regarding clouds, climate sensitivity, and aggregation, and more generally, determining which features of tropical climate a RCE framework is useful for. A novel aspect and major advantage of RCEMIP is the accessibility of the RCE framework to a variety of models, including cloud-resolving models, general circulation models, global cloud-resolving models, single-column models, and large-eddy simulation models.

Development of dark disk model of positron anomaly origin

NASA Astrophysics Data System (ADS)

Belotsky, K. M.; Kirillov, A. A.; Solovyov, M. L.

Dark disk model could be a remedy for dark matter (DM) explanation of positron anomaly (PA) in cosmic rays (CR). The main difficulty in PA explanation relates to cosmic gamma-radiation which is inevitably produced in DM annihilation or decay leading to tension with respective observation data. Introduction of “active” (producing CR) DM component concentrating in galactic disk alleviates this tension. Earlier, we considered 2-lepton modes, with branching ratios being chosen to fit in the best way all the observation data. Here we considered, in the framework of the same dark disk model, two cases: 2-body final state annihilation and 4-body one, and in each case a quark mode is added to the leptonic ones. It is shown that 4-body mode case is a little better than 2-body one from viewpoint of quality of observation data description at the fixed all other parameters (of CR propagation, background, disk height). The values of DM particle mass around 350GeV and 500GeV are more favorable for 2- and 4-body modes, respectively. Higher values would improve description of data on positrons only but accounting for data on gamma-radiation prevents it because of unwanted more abundant high-energy gamma production. Inclusion of the quark modes improves a little fitting data in both 4- and 2-body mode cases, contrary to naive expectations. In fact, quark mode has a bigger gammas yield than that of most gamma-productive leptonic mode — tau, but they are softer due to bigger final state hadron multiplicity.

Synchrotron Radiation Therapy from a Medical Physics point of view

NASA Astrophysics Data System (ADS)

Prezado, Y.; Adam, J. F.; Berkvens, P.; Martinez-Rovira, I.; Fois, G.; Thengumpallil, S.; Edouard, M.; Vautrin, M.; Deman, P.; Bräuer-Krisch, E.; Renier, M.; Elleaume, H.; Estève, F.; Bravin, A.

2010-07-01

Synchrotron radiation (SR) therapy is a promising alternative to treat brain tumors, whose management is limited due to the high morbidity of the surrounding healthy tissues. Several approaches are being explored by using SR at the European Synchrotron Radiation Facility (ESRF), where three techniques are under development Synchrotron Stereotactic Radiation Therapy (SSRT), Microbeam Radiation Therapy (MRT) and Minibeam Radiation Therapy (MBRT). The sucess of the preclinical studies on SSRT and MRT has paved the way to clinical trials currently in preparation at the ESRF. With this aim, different dosimetric aspects from both theoretical and experimental points of view have been assessed. In particular, the definition of safe irradiation protocols, the beam energy providing the best balance between tumor treatment and healthy tissue sparing in MRT and MBRT, the special dosimetric considerations for small field dosimetry, etc will be described. In addition, for the clinical trials, the definition of appropiate dosimetry protocols for patients according to the well established European Medical Physics recommendations will be discussed. Finally, the state of the art of the MBRT technical developments at the ESRF will be presented. In 2006 A. Dilmanian and collaborators proposed the use of thicker microbeams (0.36-0.68 mm). This new type of radiotherapy is the most recently implemented technique at the ESRF and it has been called MBRT. The main advantage of MBRT with respect to MRT is that it does not require high dose rates. Therefore it can be more easily applied and extended outside synchrotron sources in the future.

N3LO corrections to jet production in deep inelastic scattering using the Projection-to-Born method

NASA Astrophysics Data System (ADS)

Currie, J.; Gehrmann, T.; Glover, E. W. N.; Huss, A.; Niehues, J.; Vogt, A.

2018-05-01

Computations of higher-order QCD corrections for processes with exclusive final states require a subtraction method for real-radiation contributions. We present the first-ever generalisation of a subtraction method for third-order (N3LO) QCD corrections. The Projection-to-Born method is used to combine inclusive N3LO coefficient functions with an exclusive second-order (NNLO) calculation for a final state with an extra jet. The input requirements, advantages, and potential applications of the method are discussed, and validations at lower orders are performed. As a test case, we compute the N3LO corrections to kinematical distributions and production rates for single-jet production in deep inelastic scattering in the laboratory frame, and compare them with data from the ZEUS experiment at HERA. The corrections are small in the central rapidity region, where they stabilize the predictions to sub per-cent level. The corrections increase substantially towards forward rapidity where large logarithmic effects are expected, thereby yielding an improved description of the data in this region.

Elliptical optical solitary waves in a finite nematic liquid crystal cell

NASA Astrophysics Data System (ADS)

Minzoni, Antonmaria A.; Sciberras, Luke W.; Smyth, Noel F.; Worthy, Annette L.

2015-05-01

The addition of orbital angular momentum has been previously shown to stabilise beams of elliptic cross-section. In this article the evolution of such elliptical beams is explored through the use of an approximate methodology based on modulation theory. An approximate method is used as the equations that govern the optical system have no known exact solitary wave solution. This study brings to light two distinct phases in the evolution of a beam carrying orbital angular momentum. The two phases are determined by the shedding of radiation in the form of mass loss and angular momentum loss. The first phase is dominated by the shedding of angular momentum loss through spiral waves. The second phase is dominated by diffractive radiation loss which drives the elliptical solitary wave to a steady state. In addition to modulation theory, the "chirp" variational method is also used to study this evolution. Due to the significant role radiation loss plays in the evolution of an elliptical solitary wave, an attempt is made to couple radiation loss to the chirp variational method. This attempt furthers understanding as to why radiation loss cannot be coupled to the chirp method. The basic reason for this is that there is no consistent manner to match the chirp trial function to the generated radiating waves which is uniformly valid in time. Finally, full numerical solutions of the governing equations are compared with solutions obtained using the various variational approximations, with the best agreement achieved with modulation theory due to its ability to include both mass and angular momentum losses to shed diffractive radiation.

Addendum to Radiative corrections to the Dalitz plot of semileptonic decays of neutral baryons with light or charm quarks''

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martinez, A.; Tun, D.M.; Garcia, A.

1994-08-01

We show that the radiative corrections containing terms up to order [alpha][ital q]/[pi][ital M][sub 1] for unpolarized semileptonic decays of baryons with positron emission can be obtained by simply reversing the sign of the axial-vector form factors in the corresponding final expressions of such decays with electron emission. This rule is valid regardless of the final kinematical variables chosen and of the particular Lorentz frame in which the final results are required.

Tiros IV Radiation Data Catalog and Users' Manual

NASA Technical Reports Server (NTRS)

Kunde, V. G.

1963-01-01

The TIROS IV Meteorological Satellite contains a medium resolution scanning radiometer. Two of the channels of this instrument are sensitive to reflected solar radiation and the remaining two respond to emitted thermal radiation from the earth and its atmosphere. The two thermal channels are calibrated in terms of equivalent blackbody temperatures, and the reflected solar radiation channels in terms of effective radiant emittances. The calibration data, along with orbital and attitude data and the radiation data from the satellite, were incorporated in a computer program for an IBM 7090 which was used to produce, in binary form, the "Final Meteorological Radiation Tape" which is the basic repository of all radiation data. After launch, the radiometer displaye d the same degradation of response characteristics as did its predecessors in TIROS II and TIROS III. The onset of degradation results in a departure of the data from the prelaunch laboratory calibration. The cause of degradation has not been determined, and the matter is still being studied at the Goddard Space Flight Center. Before work with the TIROS IV radiation data is attempted, an understanding of the radiometer, its calibration, and the problems encountered in the experiment, especially from response degradation, is essential. The instrumentation design, development work, and the calibrations herein described were performed by the Goddard Space Flight Center Staff, whereas the computer and programming efforts were carried out jointly by the staffs of the National Weather Satellite Center, U. S. Weather Bureau, and the Goddard Space Flight Center. In this Catalog-Manual, the radiometer an d its calibration, data processing, the "Final Meteorological Radiation Tape", the observed degradation patterns, and possible corrections for degradation are discussed. The Catalog-Manual also includes, in two forms, documentation of each orbit of successfully reduced radiation data acquired by TIROS IV. One method of presentation is the Index of Final Meteorological Radiation Tapes and the other is a Subpoint Track, Summary of Available Radiation Data in diagrammatic form.

Regulatory requirements for nuclear power plant site selection in Malaysia-a review.

PubMed

Basri, N A; Hashim, S; Ramli, A T; Bradley, D A; Hamzah, K

2016-12-01

Malaysia has initiated a range of pre-project activities in preparation for its planned nuclear power programme. Clearly one of the first steps is the selection of sites that are deemed suitable for the construction and operation of a nuclear power plant. Here we outline the Malaysian regulatory requirements for nuclear power plant site selection, emphasizing details of the selection procedures and site characteristics needed, with a clear focus on radiation safety and radiation protection in respect of the site surroundings. The Malaysia Atomic Energy Licensing Board (AELB) site selection guidelines are in accord with those provided in International Atomic Energy Agency (IAEA) and United Stated Nuclear Regulatory Commission (USNRC) documents. To enhance the suitability criteria during selection, as well as to assist in the final decision making process, possible assessments using the site selection characteristics and information are proposed.

Charm radiative decays with neutral mesons D 0→ K¯0π 0γ , D 0→ K¯0η(η‧)γ

NASA Astrophysics Data System (ADS)

Fajfer, S.; Prapotnik, A.; Singer, P.

2002-12-01

The radiative decays D0→K¯0P0γ with nonresonant K¯0P0 (P0=π0,η,η‧) are considered within the framework which combines heavy quark effective theory and the chiral Lagrangian. Due to neutral mesons the amplitudes do not have bremsstrahlung contributions. We assume factorization for the weak matrix elements. Light (virtual) vector mesons are found to give the main contribution to the decay amplitudes. The decay D0→K¯0π0γ is predicted to have a branching ratio of 3×10-4, with comparable contributions from parity-conserving and parity-violating parts of the amplitude. The decays with η(η‧) in the final state are expected with branching ratios of 1.1×10-5 and 0.4×10-7, respectively, and are mainly parity conserving.

Analytical and Experimental Characterization of a Linear-Array Thermopile Scanning Radiometer for Geo-Synchronous Earth Radiation Budget Applications

NASA Technical Reports Server (NTRS)

Sorensen, Ira J.

1998-01-01

The Thermal Radiation Group, a laboratory in the department of Mechanical Engineering at Virginia Polytechnic Institute and State University, is currently working towards the development of a new technology for cavity-based radiometers. The radiometer consists of a 256-element linear-array thermopile detector mounted on the wall of a mirrored wedgeshaped cavity. The objective of this research is to provide analytical and experimental characterization of the proposed radiometer. A dynamic end-to-end opto-electrothermal model is developed to simulate the performance of the radiometer. Experimental results for prototype thermopile detectors are included. Also presented is the concept of the discrete Green's function to characterize the optical scattering of radiant energy in the cavity, along with a data-processing algorithm to correct for the scattering. Finally, a parametric study of the sensitivity of the discrete Green's function to uncertainties in the surface properties of the cavity is presented.

Radiative transfer and radiative driving of outflows in active galactic nuclei and starbursts

NASA Astrophysics Data System (ADS)

Novak, G. S.; Ostriker, J. P.; Ciotti, L.

2012-12-01

To facilitate the study of black hole fuelling, star formation and feedback in galaxies, we outline a method for treating the radial forces on interstellar gas due to absorption of photons by dust grains. The method gives the correct behaviour in all of the relevant limits [dominated by the central point source; dominated by the distributed isotropic source; optically thin; optically thick to ultraviolet (UV)/optical; optically thick to infrared (IR)] and reasonably interpolates between the limits when necessary. The method is explicitly energy conserving so that UV/optical photons that are absorbed are not lost, but are rather redistributed to the IR where they may scatter out of the galaxy. We implement the radiative transfer algorithm in a two-dimensional hydrodynamical code designed to study feedback processes in the context of early-type galaxies. We find that the dynamics and final state of simulations are measurably but only moderately affected by radiative forces on dust, even when assumptions about the dust-to-gas ratio are varied from zero to a value appropriate for the Milky Way. In simulations with high gas densities designed to mimic ultraluminous IR galaxies with a star formation rate of several hundred solar masses per year, dust makes a more substantial contribution to the dynamics and outcome of the simulation. We find that, despite the large opacity of dust to UV radiation, the momentum input to the flow from radiation very rarely exceeds L/c due to two factors: the low opacity of dust to the re-radiated IR and the tendency for dust to be destroyed by sputtering in hot gas environments. We also develop a simplification of our radiative transfer algorithm that respects the essential physics but is much easier to implement and requires a fraction of the computational cost.

USAF Summer Research Program - 1993 High School Apprenticeship Program Final Reports, Volume 12, Armstrong Laboratory

DTIC Science & Technology

1993-12-01

on Panasonic TLD . Panasonic Industrial Company; Secaucus, New Jersey. 5. Thurlow, Ronald M. "Neutron Dosimetry Using a Panasonic Thermoluminescent...Radiation Dosimetry Branch Brooks Air Force Base San Antonio, Texas 78235 Final Report for: AFOSR Summer Research Program Armstrong Laboratory Sponsored...Associate Radiation Dosimetry Branch Armstrong Laboratory Abstract In an attempt to improve personnel monitoring for neutron emissions, Panasonic has

Evaluation of atomic constants for optical radiation, volume 2

NASA Technical Reports Server (NTRS)

Kylstra, C. D.; Schneider, R. J.

1974-01-01

Various atomic constant for 23 elements from helium to mercury were computed and are presented in tables. The data given for each element start with the element name, its atomic number, its ionic state, and the designation and series limit for each parent configuration. This is followed by information on the energy level, parent configuration, and designation for each term available to the program. The matrix elements subtables are ordered by the sequence numbers, which represent the initial and final levels of the transitions. Each subtable gives the following: configuration of the core or parent, designation and energy level for the reference state, effective principal quantum number, energy of the series limit, value of the matrix element for the reference state interacting with itself, and sum of all of the dipole matrix elements listed in the subtable. Dipole and quadrupole interaction data are also given.

Characterizing Black Hole Mergers

NASA Technical Reports Server (NTRS)

Baker, John; Boggs, William Darian; Kelly, Bernard

2010-01-01

Binary black hole mergers are a promising source of gravitational waves for interferometric gravitational wave detectors. Recent advances in numerical relativity have revealed the predictions of General Relativity for the strong burst of radiation generated in the final moments of binary coalescence. We explore features in the merger radiation which characterize the final moments of merger and ringdown. Interpreting the waveforms in terms of an rotating implicit radiation source allows a unified phenomenological description of the system from inspiral through ringdown. Common features in the waveforms allow quantitative description of the merger signal which may provide insights for observations large-mass black hole binaries.

Idealized Cloud-System Resolving Modeling for Tropical Convection Studies

NASA Astrophysics Data System (ADS)

Anber, Usama M.

A three-dimensional limited-domain Cloud-Resolving Model (CRM) is used in idealized settings to study the interaction between tropical convection and the large scale dynamics. The model domain is doubly periodic and the large-scale circulation is parameterized using the Weak Temperature Gradient (WTG) Approximation and Damped Gravity Wave (DGW) methods. The model simulations fall into two main categories: simulations with a prescribed radiative cooling profile, and others in which radiative cooling profile interacts with clouds and water vapor. For experiments with a prescribed radiative cooling profile, radiative heating is taken constant in the vertical in the troposphere. First, the effect of turbulent surface fluxes and radiative cooling on tropical deep convection is studied. In the precipitating equilibria, an increment in surface fluxes produces a greater increase in precipitation than an equal increment in column-integrated radiative heating. The gross moist stability remains close to constant over a wide range of forcings. With dry initial conditions, the system exhibits hysteresis, and maintains a dry state with for a wide range of net energy inputs to the atmospheric column under WTG. However, for the same forcings the system admits a rainy state when initialized with moist conditions, and thus multiple equilibria exist under WTG. When the net forcing is increased enough that simulations, which begin dry, eventually develop precipitation. DGW, on the other hand, does not have the tendency to develop multiple equilibria under the same conditions. The effect of vertical wind shear on tropical deep convection is also studied. The strength and depth of the shear layer are varied as control parameters. Surface fluxes are prescribed. For weak wind shear, time-averaged rainfall decreases with shear and convection remains disorganized. For larger wind shear, rainfall increases with shear, as convection becomes organized into linear mesoscale systems. This non-monotonic dependence of rainfall on shear is observed when the imposed surface fluxes are moderate. For larger surface fluxes, convection in the unsheared basic state is already strongly organized, but increasing wind shear still leads to increasing rainfall. In addition to surface rainfall, the impacts of shear on the parameterized large-scale vertical velocity, convective mass fluxes, cloud fraction, and momentum transport are also discussed. For experiments with interactive radiative cooling profile, the effect of cloud-radiation interaction on cumulus ensemble is examined in sheared and unsheared environments with both fixed and interactive sea surface temperature (SST). For fixed SST, interactive radiation, when compared to simulations in which radiative profile has the same magnitude and vertical shape but does not interact with clouds or water vapor, is found to suppress mean precipitation by inducing strong descent in the lower troposphere, increasing the gross moist stability. For interactive SST, using a slab ocean mixed layer, there exists a shear strength above which the system becomes unstable and develops oscillatory behavior. Oscillations have periods of wet precipitating states followed by periods of dry non-precipitating states. The frequencies of oscillations are intraseasonal to subseasonal, depending on the mixed layer depth. Finally, the model is coupled to a land surface model with fully interactive radiation and surface fluxes to study the diurnal and seasonal radiation and water cycles in the Amazon basin. The model successfully captures the afternoon precipitation and cloud cover peak and the greater latent heat flux in the dry season for the first time; two major biases in GCMs with implications for correct estimates of evaporation and gross primary production in the Amazon. One of the key findings is that the fog layer near the surface in the west season is crucial for determining the surface energy budget and precipitation. This suggests that features on the diurnal time scale can significantly impact climate on the seasonal time scale.

Hadronic vacuum polarization and e+e- → μ+μ- cross section: Reanalysis with new precise data for σh with 4π final states included

NASA Astrophysics Data System (ADS)

Sauli, Vladimir

2018-05-01

The interference effect between leptonic radiative corrections and hadronic polarization functions is calculated via optical theorem for μ-pair production in vicinity of narrow resonances. Within seven most dominant exclusive channels of the production cross section σh(e+e- → hadrons) one achieves high acuracy which is necessary for the comparison with experiments. The result is compared with KLOE and KLOE2 experiments for μ-μ+ and μ-μ+γ productions at φ and ω/ρ meson energy.

Higgs-differential cross section at NNLO in dimensional regularisation

DOE PAGES

Dulat, Falko; Lionetti, Simone; Mistlberger, Bernhard; ...

2017-07-05

We present an analytic computation of the Higgs production cross section in the gluon fusion channel, which is differential in the components of the Higgs momentum and inclusive in the associated partonic radiation through NNLO in perturbative QCD. Our computation includes the necessary higher order terms in the dimensional regulator beyond the finite part that are required for renormalisation and collinear factorisation at N 3LO. We outline in detail the computational methods which we employ. We present numerical predictions for realistic final state observables, specifically distributions for the decay products of the Higgs boson in the γγ decay channel.

A comprehensive study of Interatomic Coulombic Decay in argon dimers: Extracting R-dependent absolute decay rates from the experiment

DOE PAGES

Rist, J.; Miteva, T.; Gaire, B.; ...

2016-09-15

In this paper we present a comprehensive and detailed study of Interatomic Coulombic Decay (ICD) occurring after irradiating argon dimers with XUV-synchrotron radiation. A manifold of different decay channels is observed and the corresponding initial and final states are assigned. Additionally, the effect of nuclear dynamics on the ICD electron spectrum is examined for one specific decay channel. The internuclear distance-dependent width Γ(R) of the decay is obtained from the measured kinetic energy release distribution of the ions employing a classical nuclear dynamics model.

Response of Electrical Activity in an Improved Neuron Model under Electromagnetic Radiation and Noise

PubMed Central

Zhan, Feibiao; Liu, Shenquan

2017-01-01

Electrical activities are ubiquitous neuronal bioelectric phenomena, which have many different modes to encode the expression of biological information, and constitute the whole process of signal propagation between neurons. Therefore, we focus on the electrical activities of neurons, which is also causing widespread concern among neuroscientists. In this paper, we mainly investigate the electrical activities of the Morris-Lecar (M-L) model with electromagnetic radiation or Gaussian white noise, which can restore the authenticity of neurons in realistic neural network. First, we explore dynamical response of the whole system with electromagnetic induction (EMI) and Gaussian white noise. We find that there are slight differences in the discharge behaviors via comparing the response of original system with that of improved system, and electromagnetic induction can transform bursting or spiking state to quiescent state and vice versa. Furthermore, we research bursting transition mode and the corresponding periodic solution mechanism for the isolated neuron model with electromagnetic induction by using one-parameter and bi-parameters bifurcation analysis. Finally, we analyze the effects of Gaussian white noise on the original system and coupled system, which is conducive to understand the actual discharge properties of realistic neurons. PMID:29209192

Response of Electrical Activity in an Improved Neuron Model under Electromagnetic Radiation and Noise.

PubMed

Zhan, Feibiao; Liu, Shenquan

2017-01-01

Electrical activities are ubiquitous neuronal bioelectric phenomena, which have many different modes to encode the expression of biological information, and constitute the whole process of signal propagation between neurons. Therefore, we focus on the electrical activities of neurons, which is also causing widespread concern among neuroscientists. In this paper, we mainly investigate the electrical activities of the Morris-Lecar (M-L) model with electromagnetic radiation or Gaussian white noise, which can restore the authenticity of neurons in realistic neural network. First, we explore dynamical response of the whole system with electromagnetic induction (EMI) and Gaussian white noise. We find that there are slight differences in the discharge behaviors via comparing the response of original system with that of improved system, and electromagnetic induction can transform bursting or spiking state to quiescent state and vice versa. Furthermore, we research bursting transition mode and the corresponding periodic solution mechanism for the isolated neuron model with electromagnetic induction by using one-parameter and bi-parameters bifurcation analysis. Finally, we analyze the effects of Gaussian white noise on the original system and coupled system, which is conducive to understand the actual discharge properties of realistic neurons.

Relic neutralino surface at a 100 TeV collider

DOE PAGES

Bramante, Joseph; Fox, Patrick J.; Martin, Adam; ...

2015-03-11

We map the parameter space for minimal supersymmetric Standard Model neutralino dark matter which freezes out to the observed relic abundance, in the limit that all superpartners except the neutralinos and charginos are decoupled. In this space of relic neutralinos, we show the dominant dark matter annihilation modes, the mass splittings among the electroweakinos, direct detection rates, and collider cross sections. The mass difference between the dark matter and the next-to-lightest neutral and charged states is typically much less than electroweak gauge boson masses. With these small mass differences, the relic neutralino surface is accessible to a future 100 TeVmore » hadron collider, which can discover interneutralino mass splittings down to 1 GeV and thermal relic dark matter neutralino masses up to 1.5 TeV with a few inverse attobarns of luminosity. This coverage is a direct consequence of the increased collider energy: in the Standard Model events with missing transverse momentum in the TeV range have mostly hard electroweak radiation, distinct from the soft radiation shed in compressed electroweakino decays. As a result, we exploit this kinematic feature in final states including photons and leptons, tailored to the 100 TeV collider environment.« less

Development of optical diagnostics for performance evaluation of arcjet thrusters

NASA Technical Reports Server (NTRS)

Cappelli, Mark A.

1995-01-01

Laser and optical emission-based measurements have been developed and implemented for use on low-power hydrogen arcjet thrusters and xenon-propelled electric thrusters. In the case of low power hydrogen arcjets, these laser induce fluorescence measurements constitute the first complete set of data that characterize the velocity and temperature field of such a device. The research performed under the auspices of this NASA grant includes laser-based measurements of atomic hydrogen velocity and translational temperature, ultraviolet absorption measurements of ground state atomic hydrogen, Raman scattering measurements of the electronic ground state of molecular hydrogen, and optical emission based measurements of electronically excited atomic hydrogen, electron number density, and electron temperature. In addition, we have developed a collisional-radiative model of atomic hydrogen for use in conjunction with magnetohydrodynamic models to predict the plasma radiative spectrum, and near-electrode plasma models to better understand current transfer from the electrodes to the plasma. In the final year of the grant, a new program aimed at developing diagnostics for xenon plasma thrusters was initiated, and results on the use of diode lasers for interrogating Hall accelerator plasmas has been presented at recent conferences.

Star cluster formation in a turbulent molecular cloud self-regulated by photoionization feedback

NASA Astrophysics Data System (ADS)

Gavagnin, Elena; Bleuler, Andreas; Rosdahl, Joakim; Teyssier, Romain

2017-12-01

Most stars in the Galaxy are believed to be formed within star clusters from collapsing molecular clouds. However, the complete process of star formation, from the parent cloud to a gas-free star cluster, is still poorly understood. We perform radiation-hydrodynamical simulations of the collapse of a turbulent molecular cloud using the RAMSES-RT code. Stars are modelled using sink particles, from which we self-consistently follow the propagation of the ionizing radiation. We study how different feedback models affect the gas expulsion from the cloud and how they shape the final properties of the emerging star cluster. We find that the star formation efficiency is lower for stronger feedback models. Feedback also changes the high-mass end of the stellar mass function. Stronger feedback also allows the establishment of a lower density star cluster, which can maintain a virial or sub-virial state. In the absence of feedback, the star formation efficiency is very high, as well as the final stellar density. As a result, high-energy close encounters make the cluster evaporate quickly. Other indicators, such as mass segregation, statistics of multiple systems and escaping stars confirm this picture. Observations of young star clusters are in best agreement with our strong feedback simulation.

An Experimental Investigation of the Laminar Flamelet Concept for Soot Properties

NASA Technical Reports Server (NTRS)

Diez, F. J.; Aalburg, C.; Sunderland, P. B.; Urban, D. L.; Yuan, Z.-G.; Faeth, G. M.

2007-01-01

The soot properties of round, nonbuoyant, laminar jet diffusion flames are described, based on experiments at microgravity carried out on orbit during three flights of the Space Shuttle Columbia, (Flights STS-83, 94 and 107). Experimental conditions included ethylene- and propane-fueled flames burning in still air at an ambient temperature of 300 K and ambient pressures of 35-100 kPa. Measurements included soot volume fraction distributions using deconvoluted laser extinction imaging, and soot temperature distributions using deconvoluted multiline emission imaging. Flowfield modeling based on the work of Spalding is presented. The present work explores whether soot properties of these flames are universal functions of mixture fraction, i.e., whether they satisfy soot state relationships. Measurements are presented, including radiative emissions and distributions of soot temperature and soot volume fraction. It is shown that most of the volume of these flames is bounded by the dividing streamline and thus should follow residence time state relationships. Most streamlines from the fuel supply to the surroundings are found to exhibit nearly the same maximum soot volume fraction and temperature. The radiation intensity along internal streamlines also is found to have relatively uniform values. Finally, soot state relationships were observed, i.e., soot volume fraction was found to correlate with estimated mixture fraction for each fuel/pressure selection. These results support the existence of soot property state relationships for steady nonbuoyant laminar diffusion flames, and thus in a large class of practical turbulent diffusion flames through the application of the laminar flamelet concept.

The Evolution of Gas Giant Entropy During Formation by Runaway Accretion

NASA Astrophysics Data System (ADS)

Berardo, David; Cumming, Andrew; Marleau, Gabriel-Dominique

2017-01-01

We calculate the evolution of gas giant planets during the runaway gas accretion phase of formation, to understand how the luminosity of young giant planets depends on the accretion conditions. We construct steady-state envelope models, and run time-dependent simulations of accreting planets with the code Modules for Experiments in Stellar Astrophysics. We show that the evolution of the internal entropy depends on the contrast between the internal adiabat and the entropy of the accreted material, parametrized by the shock temperature T 0 and pressure P 0. At low temperatures ({T}0≲ 300-1000 {{K}}, depending on model parameters), the accreted material has a lower entropy than the interior. The convection zone extends to the surface and can drive a high luminosity, leading to rapid cooling and cold starts. For higher temperatures, the accreted material has a higher entropy than the interior, giving a radiative zone that stalls cooling. For {T}0≳ 2000 {{K}}, the surface-interior entropy contrast cannot be accommodated by the radiative envelope, and the accreted matter accumulates with high entropy, forming a hot start. The final state of the planet depends on the shock temperature, accretion rate, and starting entropy at the onset of runaway accretion. Cold starts with L≲ 5× {10}-6 {L}⊙ require low accretion rates and starting entropy, and the temperature of the accreting material needs to be maintained close to the nebula temperature. If instead the temperature is near the value required to radiate the accretion luminosity, 4π {R}2σ {T}04˜ ({GM}\\dot{M}/R), as suggested by previous work on radiative shocks in the context of star formation, gas giant planets form in a hot start with L˜ {10}-4 {L}⊙ .

Global Weather States and Their Properties from Passive and Active Satellite Cloud Retrievals

NASA Technical Reports Server (NTRS)

Tselioudis, George; Rossow, William; Zhang, Yuanchong; Konsta, Dimitra

2013-01-01

In this study, the authors apply a clustering algorithm to International Satellite Cloud Climatology Project (ISCCP) cloud optical thickness-cloud top pressure histograms in order to derive weather states (WSs) for the global domain. The cloud property distribution within each WS is examined and the geographical variability of each WS is mapped. Once the global WSs are derived, a combination of CloudSat and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) vertical cloud structure retrievals is used to derive the vertical distribution of the cloud field within each WS. Finally, the dynamic environment and the radiative signature of the WSs are derived and their variability is examined. The cluster analysis produces a comprehensive description of global atmospheric conditions through the derivation of 11 WSs, each representing a distinct cloud structure characterized by the horizontal distribution of cloud optical depth and cloud top pressure. Matching those distinct WSs with cloud vertical profiles derived from CloudSat and CALIPSO retrievals shows that the ISCCP WSs exhibit unique distributions of vertical layering that correspond well to the horizontal structure of cloud properties. Matching the derived WSs with vertical velocity measurements shows a normal progression in dynamic regime when moving from the most convective to the least convective WS. Time trend analysis of the WSs shows a sharp increase of the fair-weather WS in the 1990s and a flattening of that increase in the 2000s. The fact that the fair-weather WS is the one with the lowest cloud radiative cooling capability implies that this behavior has contributed excess radiative warming to the global radiative budget during the 1990s.

First observation of exclusive {chi}{sub cJ} decays to two charged and two neutral hadrons

DOE Office of Scientific and Technical Information (OSTI.GOV)

He, Q.; Insler, J.; Muramatsu, H.

2008-11-01

We study exclusive {chi}{sub c0,1,2} decays to four-hadron final states involving two charged and two neutral hadrons: {pi}{sup +}{pi}{sup -}{pi}{sup 0}{pi}{sup 0}, K{sup +}K{sup -}{pi}{sup 0}{pi}{sup 0}, pp{pi}{sup 0}{pi}{sup 0}, K{sup +}K{sup -}{eta}{pi}{sup 0}, and K{sup {+-}}{pi}{sup {+-}}K{sup 0}{pi}{sup 0}. The {chi}{sub c} states are produced in radiative decays of 3.08x10{sup 6} {psi}(2S) resonance decays and observed in the CLEO detector. We also measure the largest substructure contributions to the modes {pi}{sup +}{pi}{sup -}{pi}{sup 0}{pi}{sup 0} and K{sup {+-}}{pi}{sup {+-}}K{sup 0}{pi}{sup 0}.

Linearized Flux Evolution (LiFE): A technique for rapidly adapting fluxes from full-physics radiative transfer models

NASA Astrophysics Data System (ADS)

Robinson, Tyler D.; Crisp, David

2018-05-01

Solar and thermal radiation are critical aspects of planetary climate, with gradients in radiative energy fluxes driving heating and cooling. Climate models require that radiative transfer tools be versatile, computationally efficient, and accurate. Here, we describe a technique that uses an accurate full-physics radiative transfer model to generate a set of atmospheric radiative quantities which can be used to linearly adapt radiative flux profiles to changes in the atmospheric and surface state-the Linearized Flux Evolution (LiFE) approach. These radiative quantities describe how each model layer in a plane-parallel atmosphere reflects and transmits light, as well as how the layer generates diffuse radiation by thermal emission and by scattering light from the direct solar beam. By computing derivatives of these layer radiative properties with respect to dynamic elements of the atmospheric state, we can then efficiently adapt the flux profiles computed by the full-physics model to new atmospheric states. We validate the LiFE approach, and then apply this approach to Mars, Earth, and Venus, demonstrating the information contained in the layer radiative properties and their derivatives, as well as how the LiFE approach can be used to determine the thermal structure of radiative and radiative-convective equilibrium states in one-dimensional atmospheric models.

Results of the 2013-2015 Association of Residents in Radiation Oncology Survey of Chief Residents in the United States.

PubMed

Nabavizadeh, Nima; Burt, Lindsay M; Mancini, Brandon R; Morris, Zachary S; Walker, Amanda J; Miller, Seth M; Bhavsar, Shripal; Mohindra, Pranshu; Kim, Miranda B; Kharofa, Jordan

2016-02-01

The purpose of this project was to survey radiation oncology chief residents to define their residency experience and readiness for independent practice. During the academic years 2013 to 2014 and 2014 to 2015, the Association of Residents in Radiation Oncology (ARRO) conducted an electronic survey of post-graduate year-5 radiation oncology residents in the United States during the final 3 months of training. Descriptive statistics are reported. Sixty-six chief residents completed the survey in 2013 to 2014 (53% response rate), and 69 completed the survey in 2014 to 2015 (64% response rate). Forty to 85% percent of residents reported inadequate exposure to high-dose rate and low-dose rate brachytherapy. Nearly all residents in both years (>90%) reported adequate clinical experience for the following disease sites: breast, central nervous system, gastrointestinal, genitourinary, head and neck, and lung. However, as few as 56% reported adequate experience in lymphoma or pediatric malignancies. More than 90% of residents had participated in retrospective research projects, with 20% conducting resident-led prospective clinical trials and 50% conducting basic science or translational projects. Most chief residents reported working 60 or fewer hours per week in the clinical/hospital setting and performing fewer than 15 hours per week tasks that were considered to have little or no educational value. There was more than 80% compliance with Accreditation Council for Graduate Medical Education (ACGME) work hour limits. Fifty-five percent of graduating residents intended to join an established private practice group, compared to 25% who headed for academia. Residents perceive the job market to be more competitive than previous years. This first update of the ARRO chief resident survey since the 2007 to 2008 academic year documents US radiation oncology residents' experiences and conditions over a 2-year period. This analysis may serve as a valuable tool for those seeking to improve training of the next generation of oncology leaders. Copyright © 2016 Elsevier Inc. All rights reserved.

Results of the 2012-2013 Association of Residents in Radiation Oncology (ARRO) Job Search and Career Planning Survey of Graduating Residents in the United States

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mattes, Malcolm D., E-mail: mdm9007@nyp.org; Kharofa, Jordan; Zeidan, Youssef H.

Purpose/Objective(s): To determine the timeline used by postgraduate year (PGY)-5 radiation oncology residents during the job application process and the factors most important to them when deciding on a first job. Methods and Materials: In 2012 and 2013, the Association of Residents in Radiation Oncology conducted a nationwide electronic survey of PGY-5 radiation oncology residents in the United States during the final 2 months of their training. Descriptive statistics are reported. In addition, subgroup analysis was performed. Results: Surveys were completed by 180 of 314 residents contacted. The median time to start networking for the purpose of employment was Januarymore » PGY-4; to start contacting practices, complete and upload a curriculum vitae to a job search website, and use the American Society of Radiation Oncology Career Center was June PGY-4; to obtain letters of recommendation was July PGY-5; to start interviewing was August PGY-5; to finish interviewing was December PGY-5; and to accept a contract was January PGY-5. Those applying for a community position began interviewing at an earlier average time than did those applying for an academic position (P=.04). The most important factors to residents when they evaluated job offers included (in order from most to least important) a collegial environment, geographic location, emphasis on best patient care, quality of support staff and facility, and multidisciplinary approach to patient care. Factors that were rated significantly different between subgroups based on the type of position applied for included adequate mentoring, dedicated research time, access to clinical trials, amount of time it takes to become a partner, geographic location, size of group, starting salary, and amount of vacation and days off. Conclusions: The residents' perspective on the job application process over 2 years is documented to provide a resource for current and future residents and employers to use.« less

A NUMERICAL ALGORITHM FOR MODELING MULTIGROUP NEUTRINO-RADIATION HYDRODYNAMICS IN TWO SPATIAL DIMENSIONS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Swesty, F. Douglas; Myra, Eric S.

It is now generally agreed that multidimensional, multigroup, neutrino-radiation hydrodynamics (RHD) is an indispensable element of any realistic model of stellar-core collapse, core-collapse supernovae, and proto-neutron star instabilities. We have developed a new, two-dimensional, multigroup algorithm that can model neutrino-RHD flows in core-collapse supernovae. Our algorithm uses an approach similar to the ZEUS family of algorithms, originally developed by Stone and Norman. However, this completely new implementation extends that previous work in three significant ways: first, we incorporate multispecies, multigroup RHD in a flux-limited-diffusion approximation. Our approach is capable of modeling pair-coupled neutrino-RHD, and includes effects of Pauli blocking inmore » the collision integrals. Blocking gives rise to nonlinearities in the discretized radiation-transport equations, which we evolve implicitly in time. We employ parallelized Newton-Krylov methods to obtain a solution of these nonlinear, implicit equations. Our second major extension to the ZEUS algorithm is the inclusion of an electron conservation equation that describes the evolution of electron-number density in the hydrodynamic flow. This permits calculating deleptonization of a stellar core. Our third extension modifies the hydrodynamics algorithm to accommodate realistic, complex equations of state, including those having nonconvex behavior. In this paper, we present a description of our complete algorithm, giving sufficient details to allow others to implement, reproduce, and extend our work. Finite-differencing details are presented in appendices. We also discuss implementation of this algorithm on state-of-the-art, parallel-computing architectures. Finally, we present results of verification tests that demonstrate the numerical accuracy of this algorithm on diverse hydrodynamic, gravitational, radiation-transport, and RHD sample problems. We believe our methods to be of general use in a variety of model settings where radiation transport or RHD is important. Extension of this work to three spatial dimensions is straightforward.« less

Results of the 2012-2013 Association of Residents in Radiation Oncology (ARRO) job search and career planning survey of graduating residents in the United States.

PubMed

Mattes, Malcolm D; Kharofa, Jordan; Zeidan, Youssef H; Tung, Kaity; Gondi, Vinai; Golden, Daniel W

2014-01-01

To determine the timeline used by postgraduate year (PGY)-5 radiation oncology residents during the job application process and the factors most important to them when deciding on a first job. In 2012 and 2013, the Association of Residents in Radiation Oncology conducted a nationwide electronic survey of PGY-5 radiation oncology residents in the United States during the final 2 months of their training. Descriptive statistics are reported. In addition, subgroup analysis was performed. Surveys were completed by 180 of 314 residents contacted. The median time to start networking for the purpose of employment was January PGY-4; to start contacting practices, complete and upload a curriculum vitae to a job search website, and use the American Society of Radiation Oncology Career Center was June PGY-4; to obtain letters of recommendation was July PGY-5; to start interviewing was August PGY-5; to finish interviewing was December PGY-5; and to accept a contract was January PGY-5. Those applying for a community position began interviewing at an earlier average time than did those applying for an academic position (P=.04). The most important factors to residents when they evaluated job offers included (in order from most to least important) a collegial environment, geographic location, emphasis on best patient care, quality of support staff and facility, and multidisciplinary approach to patient care. Factors that were rated significantly different between subgroups based on the type of position applied for included adequate mentoring, dedicated research time, access to clinical trials, amount of time it takes to become a partner, geographic location, size of group, starting salary, and amount of vacation and days off. The residents' perspective on the job application process over 2 years is documented to provide a resource for current and future residents and employers to use. Copyright © 2014 Elsevier Inc. All rights reserved.

Progress in high-dose radiation dosimetry. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ettinger, K.V.; Nam, J.W.; McLaughlin, W.L.

1981-01-01

The last decade has witnessed a deluge of new high-dose dosimetry techniques and expended applications of methods developed earlier. Many of the principal systems are calibrated by means of calorimetry, although production of heat is not always the final radiation effect of interest. Requirements for a stable and reliable transfer dose meters have led to further developments of several important high-dose systems: thermoluminescent materials, radiochromic dyes, ceric-cerous solutions analyzed by high-frequency oscillometry. A number of other prospective dosimeters are also treated in this review. In addition, an IAEA program of high-dose intercomparison and standardization for industrial radiation processing is described.

Progress in high-dose radiation dosimetry. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ettinger, K.V.; Nam, J.W.; McLaughlin, W.L.

1981-01-01

The last decade has witnessed a deluge of new high-dose dosimetry techniques and expended applications of methods developed earlier. Many of the principal systems are calibrated by means of calorimetry, although production of heat is not always the final radiation effect of interest. Requirements for a stable and reliable transfer dose meters have led to further developments of several important high-dose systems: thermoluminescent materials, radiochromic dyes, ceric-cerous solutions analyzed by high-frequency oscillometry. A number of other prospective dosimeters also treated in this review. In addition, an IAEA programme of high-dose intercomparison and standardization for industrial radiation processing is described.

FINAL REPORT (DE-FG02-97ER62338): Single-column modeling, GCM parameterizations, and ARM data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Richard C. J. Somerville

2009-02-27

Our overall goal is the development of new and improved parameterizations of cloud-radiation effects and related processes, using ARM data at all three ARM sites, and the implementation and testing of these parameterizations in global models. To test recently developed prognostic parameterizations based on detailed cloud microphysics, we have compared SCM (single-column model) output with ARM observations at the SGP, NSA and TWP sites. We focus on the predicted cloud amounts and on a suite of radiative quantities strongly dependent on clouds, such as downwelling surface shortwave radiation. Our results demonstrate the superiority of parameterizations based on comprehensive treatments ofmore » cloud microphysics and cloud-radiative interactions. At the SGP and NSA sites, the SCM results simulate the ARM measurements well and are demonstrably more realistic than typical parameterizations found in conventional operational forecasting models. At the TWP site, the model performance depends strongly on details of the scheme, and the results of our diagnostic tests suggest ways to develop improved parameterizations better suited to simulating cloud-radiation interactions in the tropics generally. These advances have made it possible to take the next step and build on this progress, by incorporating our parameterization schemes in state-of-the-art three-dimensional atmospheric models, and diagnosing and evaluating the results using independent data. Because the improved cloud-radiation results have been obtained largely via implementing detailed and physically comprehensive cloud microphysics, we anticipate that improved predictions of hydrologic cycle components, and hence of precipitation, may also be achievable.« less

Advanced Space Radiation Detector Technology Development

NASA Technical Reports Server (NTRS)

Wrbanek, John D.; Wrbanek, Susan Y.; Fralick, Gustave C.

2013-01-01

The advanced space radiation detector development team at the NASA Glenn Research Center (GRC) has the goal of developing unique, more compact radiation detectors that provide improved real-time data on space radiation. The team has performed studies of different detector designs using a variety of combinations of solid-state detectors, which allow higher sensitivity to radiation in a smaller package and operate at lower voltage than traditional detectors. Integration of multiple solid-state detectors will result in an improved detector system in comparison to existing state-of-the-art instruments for the detection and monitoring of the space radiation field for deep space and aerospace applications.

Advanced Space Radiation Detector Technology Development

NASA Technical Reports Server (NTRS)

Wrbanek, John D.; Wrbanek, Susan Y.; Fralick, Gustave C.

2013-01-01

The advanced space radiation detector development team at NASA Glenn Research Center (GRC) has the goal of developing unique, more compact radiation detectors that provide improved real-time data on space radiation. The team has performed studies of different detector designs using a variety of combinations of solid-state detectors, which allow higher sensitivity to radiation in a smaller package and operate at lower voltage than traditional detectors. Integration of multiple solid-state detectors will result in an improved detector system in comparison to existing state-of-the-art instruments for the detection and monitoring of the space radiation field for deep space and aerospace applications.

Advanced Space Radiation Detector Technology Development

NASA Technical Reports Server (NTRS)

Wrbanek, John D.; Wrbanek, Susan Y.; Fralick, Gustave C.

2013-01-01

The advanced space radiation detector development team at NASA Glenn Research Center (GRC) has the goal of developing unique, more compact radiation detectors that provide improved real-time data on space radiation. The team has performed studies of different detector designs using a variety of combinations of solid-state detectors, which allow higher sensitivity to radiation in a smaller package and operate at lower voltage than traditional detectors. Integration of multiple solid-state detectors will result in an improved detector system in comparison to existing state-of-the-art (SOA) instruments for the detection and monitoring of the space radiation field for deep space and aerospace applications.

Radiation sterilization of aseptically manufactured products.

PubMed

Fairand, Barry P; Fidopiastis, Niki

2010-01-01

This paper discusses an approach for establishing a sterilization dose for an aseptically processed product after the product is in its final packaged state, in other words, terminal sterilization. It applies to aseptic processes where the fill/finish operation is conducted in a closed system using isolator or restricted access barrier technology, that is, no human intervention. The example that is given in this paper uses gamma radiation as the sterilizing agent. Other forms of radiation such as high-energy electrons or X-rays also could serve as the sterilizing agent. The proposed approach involves irradiation of the aseptically processed product at very low doses of radiation, which is possible due to the extremely low levels of bioburden that may be present on the product following a fill/finish operation. Rather than sacrificing a large number of product units that may be required to obtain a statistically significant sampling of the product for bioburden analysis and other test purposes, the test unit is a surrogate consisting of actual pharmaceutical product that was inoculated with a highly radiation-resistant micro-organism. Selection of the microorganism was based on analysis of a library of environmental monitoring data taken from the aseptic area. Because of microbial diversity between different aseptic processing facilities, selection of the test microorganism would depend on the aseptic area under study. The approach that is discussed in this paper addresses selection and preparation of the surrogate, test of sterility of the surrogate following irradiation, determination of the radiation resistance of the test microorganism, and application of the approach to calculate a sterilization dose that is less than 10 kGy. At this low dose, it may be possible to terminally sterilize radiation-sensitive pharmaceutical products, for example, those in liquid form. Additional studies are warranted to determine the general applicability of the proposed approach.

Acoustic radiation force control: Pulsating spherical carriers.

PubMed

Rajabi, Majid; Mojahed, Alireza

2018-02-01

The interaction between harmonic plane progressive acoustic beams and a pulsating spherical radiator is studied. The acoustic radiation force function exerted on the spherical body is derived as a function of the incident wave pressure and the monopole vibration characteristics (i.e., amplitude and phase) of the body. Two distinct strategies are presented in order to alter the radiation force effects (i.e., pushing and pulling states) by changing its magnitude and direction. In the first strategy, an incident wave field with known amplitude and phase is considered. It is analytically shown that the zero- radiation force state (i.e., radiation force function cancellation) is achievable for specific pulsation characteristics belong to a frequency-dependent straight line equation in the plane of real-imaginary components (i.e., Nyquist Plane) of prescribed surface displacement. It is illustrated that these characteristic lines divide the mentioned displacement plane into two regions of positive (i.e., pushing) and negative (i.e., pulling) radiation forces. In the second strategy, the zero, negative and positive states of radiation force are obtained through adjusting the incident wave field characteristics (i.e., amplitude and phase) which insonifies the radiator with prescribed pulsation characteristics. It is proved that zero radiation force state occurs for incident wave pressure characteristics belong to specific frequency-dependent circles in Nyquist plane of incident wave pressure. These characteristic circles divide the Nyquist plane into two distinct regions corresponding to positive (out of circles) and negative (in the circles) values of radiation force function. It is analytically shown that the maximum amplitude of negative radiation force is exactly equal to the amplitude of the (positive) radiation force exerted upon the sphere in the passive state, by the same incident field. The developed concepts are much more deepened by considering the required power supply for distinct cases of zero, negative and positive radiation force states along with the frequency dependent asymmetry index. In addition, considering the effect of phase difference between the incident wave field and the pulsating object, and its possible variation with respect to spatial position of object, some practical points about the spatial average of generated radiation force, the optimal state of operation, the stability of zero radiation force states and the possibly of precise motion control are discussed. This work would extend the novel concept of smart carriers to and may be helpful for robust single-beam acoustic handling techniques. Furthermore, the shown capability of precise motion control may be considered as a new way toward smart acoustic driven micro-mechanisms and micro-machines. Copyright © 2017 Elsevier B.V. All rights reserved.

Universe of constant

NASA Astrophysics Data System (ADS)

Yongquan, Han

2016-10-01

The ideal gas state equation is not applicable to ordinary gas, it should be applied to the Electromagnetic ``gas'' that is applied to the radiation, the radiation should be the ultimate state of matter changes or initial state, the universe is filled with radiation. That is, the ideal gas equation of state is suitable for the Singular point and the universe. Maybe someone consider that, there is no vessel can accommodate radiation, it is because the Ordinary container is too small to accommodate, if the radius of your container is the distance that Light through an hour, would you still think it can't accommodates radiation? Modern scientific determinate that the radius of the universe now is about 1027 m, assuming that the universe is a sphere whose volume is approximately: V = 4.19 × 1081 cubic meters, the temperature radiation of the universe (cosmic microwave background radiation temperature of the universe, should be the closest the average temperature of the universe) T = 3.15k, radiation pressure P = 5 × 10-6 N / m 2, according to the law of ideal gas state equation, PV / T = constant = 6 × 1075, the value of this constant is the universe, The singular point should also equal to the constant Author: hanyongquan

The change law of the universe

NASA Astrophysics Data System (ADS)

Yongquan, Han

The ideal gas state equation is not applicable to ordinary gas, it should be applied to the Electromagnetic ''gas'' that is applied to the radiation, the radiation should be the ultimate state of matter changes or initial state, the universe is filled with radiation. That is, the ideal gas equation of state is suitable for the Singular point and the universe. Maybe someone consider that, there is no vessel can accommodate radiation, it is because the Ordinary container is too small to accommodate, if the radius of your container is the distance that Light through an hour, would you still think it can't accommodates radiation? Modern scientific determinate that the radius of the universe now is about 1027 m, assuming that the universe is a sphere whose volume is approximately: V = 4.19 × 1081 cubic meters, the temperature radiation of the universe (cosmic microwave background radiation temperature of the universe, should be the closest the average temperature of the universe) T = 3.15k, radiation pressure P = 5 Ã 10-6 N / m 2, according to the law of ideal gas state equation, PV / T = 6 à 1075, the value of this constant is the universe, The singular point should also equal to the constant

Semi-inclusive wino and higgsino annihilation to LL'

DOE PAGES

Baumgart, Matthew; Vaidya, Varun

2016-03-31

Here, we systematically compute the annihilation rate for winos and higgsinos into the final state relevant for indirect detection experiments, γ + X. The radiative corrections to this process receive enhancement from the large Bloch-Nordsieck-Violating Sudakov logarithm, log(2Mmore » $${\\chi }$$/M W). We resum the double logs and include single logs to fixed order using a formalism that combines nonrelativistic and soft-collinear effective field theories. For the wino case, we update an earlier exclusion adapting results of the HESS experiment. At the thermal relic mass of 3 TeV, LL' corrections result in a ~30% reduction in rate relative to LL. But, single logs do not save the wino, and it is still excluded by an order of magnitude. Finally, experimental cuts produce an endpoint region which, our results show, significantly effects the higgsino rate at its thermal-relic mass near 1 TeV and is deserving of further study.« less

MOSFET and MOS capacitor responses to ionizing radiation

NASA Technical Reports Server (NTRS)

Benedetto, J. M.; Boesch, H. E., Jr.

1984-01-01

The ionizing radiation responses of metal oxide semiconductor (MOS) field-effect transistors (FETs) and MOS capacitors are compared. It is shown that the radiation-induced threshold voltage shift correlates closely with the shift in the MOS capacitor inversion voltage. The radiation-induced interface-state density of the MOSFETs and MOS capacitors was determined by several techniques. It is shown that the presence of 'slow' states can interfere with the interface-state measurements.

Simulation of inverse Compton scattering and its implications on the scattered linewidth

NASA Astrophysics Data System (ADS)

Ranjan, N.; Terzić, B.; Krafft, G. A.; Petrillo, V.; Drebot, I.; Serafini, L.

2018-03-01

Rising interest in inverse Compton sources has increased the need for efficient models that properly quantify the behavior of scattered radiation given a set of interaction parameters. The current state-of-the-art simulations rely on Monte Carlo-based methods, which, while properly expressing scattering behavior in high-probability regions of the produced spectra, may not correctly simulate such behavior in low-probability regions (e.g. tails of spectra). Moreover, sampling may take an inordinate amount of time for the desired accuracy to be achieved. In this paper, we present an analytic derivation of the expression describing the scattered radiation linewidth and propose a model to describe the effects of horizontal and vertical emittance on the properties of the scattered radiation. We also present an improved version of the code initially reported in Krafft et al. [Phys. Rev. Accel. Beams 19, 121302 (2016), 10.1103/PhysRevAccelBeams.19.121302], that can perform the same simulations as those present in cain and give accurate results in low-probability regions by integrating over the emissions of the electrons. Finally, we use these codes to carry out simulations that closely verify the behavior predicted by the analytically derived scaling law.

Simulation of inverse Compton scattering and its implications on the scattered linewidth

DOE PAGES

Ranjan, N.; Terzić, B.; Krafft, G. A.; ...

2018-03-06

Rising interest in inverse Compton sources has increased the need for efficient models that properly quantify the behavior of scattered radiation given a set of interaction parameters. The current state-of-the-art simulations rely on Monte Carlo-based methods, which, while properly expressing scattering behavior in high-probability regions of the produced spectra, may not correctly simulate such behavior in low-probability regions (e.g. tails of spectra). Moreover, sampling may take an inordinate amount of time for the desired accuracy to be achieved. Here in this article, we present an analytic derivation of the expression describing the scattered radiation linewidth and propose a model tomore » describe the effects of horizontal and vertical emittance on the properties of the scattered radiation. We also present an improved version of the code initially reported in Krafft et al. [Phys. Rev. Accel. Beams 19, 121302 (2016)], that can perform the same simulations as those present in cain and give accurate results in low-probability regions by integrating over the emissions of the electrons. Finally, we use these codes to carry out simulations that closely verify the behavior predicted by the analytically derived scaling law.« less

Radiation and scattering from cylindrically conformal printed antennas. Ph.D. Thesis Final Report

NASA Technical Reports Server (NTRS)

Kempel, Leo C.; Volakis, John L.

1994-01-01

Microstrip patch antennas offer considerable advantages in terms of weight, aerodynamic drag, cost, flexibility, and observables over more conventional protruding antennas. These flat patch antennas were first proposed over thirty years ago by Deschamps in the United States and Gutton and Baisinot in France. Such antennas have been analyzed and developed for planar as well as curved platforms. However, the methods used in these designs employ gross approximations, suffer from extreme computational burden, or require expensive physical experiments. The goal of this thesis is to develop accurate and efficient numerical modeling techniques which represent actual antenna structures mounted on curved surfaces with a high degree of fidelity. In this thesis, the finite element method is extended to cavity-backed conformal antenna arrays embedded in a circular, metallic, infinite cylinder. Both the boundary integral and absorbing boundary mesh closure conditions will be used for terminating the mesh. These two approaches will be contrasted and used to study the scattering and radiation behavior of several useful antenna configurations. An important feature of this study will be to examine the effect of curvature and cavity size on the scattering and radiation properties of wraparound conformal antenna arrays.

High-temperature partition functions, specific heats and spectral radiative properties of diatomic molecules with an improved calculation of energy levels

NASA Astrophysics Data System (ADS)

Qin, Z.; Zhao, J. M.; Liu, L. H.

2018-05-01

The level energies of diatomic molecules calculated by the frequently used Dunham expansion will become less accurate for high-lying vibrational and rotational levels. In this paper, the potential curves for the lower-lying electronic states with accurate spectroscopic constants are reconstructed using the Rydberg-Klein-Rees (RKR) method, which are extrapolated to the dissociation limits by fitting of the theoretical potentials, and the rest of the potential curves are obtained from the ab-initio results in the literature. Solving the rotational dependence of the radial Schrödinger equation over the obtained potential curves, we determine the rovibrational level energies, which are then used to calculate the equilibrium and non-equilibrium thermodynamic properties of N2, N2+, NO, O2, CN, C2, CO and CO+. The partition functions and the specific heats are systematically validated by available data in the literature. Finally, we calculate the radiative source strengths of diatomic molecules in thermodynamic equilibrium, which agree well with the available values in the literature. The spectral radiative intensities for some diatomic molecules in thermodynamic non-equilibrium are calculated and validated by available experimental data.

Modeling of polarimetric BRDF characteristics of painted surfaces

NASA Astrophysics Data System (ADS)

Zhang, Ying; Wang, Zeying; Zhao, Huijie

2014-11-01

In this paper a pBRDF (polarimetric Bidirectional Reflectance Distribution Function) model of painted surfaces coupled with atmospheric polarization characteristics is built and the method of simulating polarimetric radiation reaching the imaging system is advanced. Firstly, the composition of the radiation reaching the sensor is analyzed. Then, the pBRDF model of painted surfaces is developed according to the microfacet theory presented by G. Priest and the downwelled skylight polarization is modeled based on the vector radiative transfer model RT3. Furthermore, the modeled polarization state of reflected light from the surfaces was achieved through integrating the directional polarimetric information of the whole hemisphere, adding the modeled polarimetric factors of incident diffused skylight. Finally, the polarimetric radiance reaching the sensor is summed up with the assumption that the target-sensor path is assumed to be negligible since it is relatively short in the current imaging geometry. The modeled results are related to the solar-sensor geometry, atmospheric conditions and the features of the painted surfaces. This result can be used to simulate the imaging under different weather conditions and further work for the validation experiments of the model need to be done.

Magnetic fields in non-convective regions of stars.

PubMed

Braithwaite, Jonathan; Spruit, Henk C

2017-02-01

We review the current state of knowledge of magnetic fields inside stars, concentrating on recent developments concerning magnetic fields in stably stratified (zones of) stars, leaving out convective dynamo theories and observations of convective envelopes. We include the observational properties of A, B and O-type main-sequence stars, which have radiative envelopes, and the fossil field model which is normally invoked to explain the strong fields sometimes seen in these stars. Observations seem to show that Ap-type stable fields are excluded in stars with convective envelopes. Most stars contain both radiative and convective zones, and there are potentially important effects arising from the interaction of magnetic fields at the boundaries between them; the solar cycle being one of the better known examples. Related to this, we discuss whether the Sun could harbour a magnetic field in its core. Recent developments regarding the various convective and radiative layers near the surfaces of early-type stars and their observational effects are examined. We look at possible dynamo mechanisms that run on differential rotation rather than convection. Finally, we turn to neutron stars with a discussion of the possible origins for their magnetic fields.

Magnetic fields in non-convective regions of stars

PubMed Central

Braithwaite, Jonathan

2017-01-01

We review the current state of knowledge of magnetic fields inside stars, concentrating on recent developments concerning magnetic fields in stably stratified (zones of) stars, leaving out convective dynamo theories and observations of convective envelopes. We include the observational properties of A, B and O-type main-sequence stars, which have radiative envelopes, and the fossil field model which is normally invoked to explain the strong fields sometimes seen in these stars. Observations seem to show that Ap-type stable fields are excluded in stars with convective envelopes. Most stars contain both radiative and convective zones, and there are potentially important effects arising from the interaction of magnetic fields at the boundaries between them; the solar cycle being one of the better known examples. Related to this, we discuss whether the Sun could harbour a magnetic field in its core. Recent developments regarding the various convective and radiative layers near the surfaces of early-type stars and their observational effects are examined. We look at possible dynamo mechanisms that run on differential rotation rather than convection. Finally, we turn to neutron stars with a discussion of the possible origins for their magnetic fields. PMID:28386410

Space Radiation Effects on Electronics: Simple Concepts and New Challenges

NASA Technical Reports Server (NTRS)

LaBel, Kenneth A.

2004-01-01

This viewgraph presentation covers the following topics: 1) The Space Radiation Environment; 2) The Effects on Electronics; 3) The Environment in Action; 4) NASA Approaches to Commercial Electronics; 5) Final Thoughts.

Calibration of solar radiation measuring instruments. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bahm, R J; Nakos, J C

A review of solar radiation measurement of instruments and some types of errors is given; and procedures for calibrating solar radiation measuring instruments are detailed. An appendix contains a description of various agencies who perform calibration of solar instruments and a description of the methods they used at the time this report was prepared. (WHK)

[Participation of final products of lipid peroxidation in the anticancer mechanism of ionizing radiation and radiomimetic cytostatics].

PubMed

Przybyszewski, W M

2001-01-01

This review reports the evidence for the participation of final products of lipid peroxidation in the anticancer mechanism of ionising radiation and radiomimetic cytostatics. Processes of lipid peroxidation occur endogenously in response to oxidative stress and great diversity of reactive metabolites is formed. However, direct observation of radical reaction in pathophysiology of cells, tissues and organs is limited technically. Most investigations focused on the indirect assessment of their final products, aldehydes. The peroxidative breakdown of polyunsaturated fatty acids is believed to be involved in the regulation of cell division, and antitumor effect through biochemical and genetic processes.

Intense terahertz radiation from relativistic laser–plasma interactions

DOE PAGES

Liao, G. Q.; Li, Y. T.; Li, C.; ...

2016-11-02

The development of tabletop intense terahertz (THz) radiation sources is extremely important for THz science and applications. This study presents our measurements of intense THz radiation from relativistic laser–plasma interactions under different experimental conditions. Several THz generation mechanisms have been proposed and investigated, including coherent transition radiation (CTR) emitted by fast electrons from the target rear surface, transient current radiation at the front of the target, and mode conversion from electron plasma waves (EPWs) to THz waves. Finally, the results indicate that relativistic laser plasma is a promising driver of intense THz radiation sources.

Impact of state-specific flowfield modeling on atomic nitrogen radiation

NASA Astrophysics Data System (ADS)

Johnston, Christopher O.; Panesi, Marco

2018-01-01

A hypersonic flowfield model that treats electronic levels of the dominant afterbody radiator N as individual species is presented. This model allows electron-ion recombination rate and two-temperature modeling improvements, the latter which are shown to decrease afterbody radiative heating by up to 30%. This decrease is primarily due to the addition of the electron-impact excitation energy-exchange term to the energy equation governing the vibrational-electronic electron temperature. This model also allows the validity of the often applied quasi-steady-state (QSS) approximation to be assessed. The QSS approximation is shown to fail throughout most of the afterbody region for lower electronic states, although this impacts the radiative intensity reaching the surface by less than 15%. By computing the electronic-state populations of N within the flowfield solver, instead of through the QSS approximation in the radiation solver, the coupling of nonlocal radiative transition rates to the species continuity equations becomes feasible. Implementation of this higher-fidelity level of coupling between the flowfield and radiation solvers is shown to increase the afterbody radiation by up to 50% relative to the conventional model.

Radiation-Hardened Circuitry Using Mask-Programmable Analog Arrays. Final Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Britton, Jr., Charles L.; Ericson, Milton Nance; Bobrek, Miljko

As the recent accident at Fukushima Daiichi so vividly demonstrated, telerobotic technologies capable of withstanding high radiation environments need to be readily available to enable operations, repair, and recovery under severe accident scenarios where human entry is extremely dangerous or not possible. Telerobotic technologies that enable remote operation in high dose rate environments have undergone revolutionary improvement over the past few decades. However, much of this technology cannot be employed in nuclear power environments due the radiation sensitivity of the electronics and the organic insulator materials currently in use. This is the final report of the activities involving the NEETmore » 2 project Radiation Hardened Circuitry Using Mask-Programmable Analog Arrays. We present a detailed functional block diagram of the proposed data acquisition system, the thought process leading to technical decisions, the implemented system, and the tested results from the systems. This system will be capable of monitoring at least three parameters of importance to nuclear reactor monitoring: temperature, radiation level, and pressure.« less

A Self-Powered Thin-Film Radiation Detector Using Intrinsic High-Energy Current (HEC) (Author’s Final Version)

DTIC Science & Technology

2016-09-08

10.1118/1.4935531. A new radiation detection method relies on high-energy current (HEC) formed by secondary charged particles in the detector material...photocurrent, radiation detection , self-powered, thin-film U U U SAR 17 Dr. Joseph Wander Reset A Self-powered thin-film radiation detector using intrinsic...Program, Lowell, MA 01854 Purpose: We introduce a radiation detection method that relies on high-energy current (HEC) formed by secondary 10 charged

Radiative transitions from Rydberg states of lithium atoms in a blackbody radiation environment

NASA Astrophysics Data System (ADS)

Glukhov, I. L.; Ovsiannikov, V. D.

2012-05-01

The radiative widths induced by blackbody radiation (BBR) were investigated for Rydberg states with principal quantum number up to n = 1000 in S-, P- and D-series of the neutral lithium atom at temperatures T = 100-3000 K. The rates of BBR-induced decays and excitations were compared with the rates of spontaneous decays. Simple analytical approximations are proposed for accurate estimations of the ratio of thermally induced decay (excitation) rates to spontaneous decay rates in wide ranges of states and temperatures.

Atmospheric State, Cloud Microphysics and Radiative Flux

DOE Data Explorer

Mace, Gerald

2008-01-15

Atmospheric thermodynamics, cloud properties, radiative fluxes and radiative heating rates for the ARM Southern Great Plains (SGP) site. The data represent a characterization of the physical state of the atmospheric column compiled on a five-minute temporal and 90m vertical grid. Sources for this information include raw measurements, cloud property and radiative retrievals, retrievals and derived variables from other third-party sources, and radiative calculations using the derived quantities.

Solar radiation alert system : final report.

DOT National Transportation Integrated Search

2009-03-01

The Solar Radiation Alert (SRA) system continuously evaluates measurements of high-energy protons made by instruments on GOES satellites. If the measurements indicate a substantial elevation of effective dose rates at aircraft flight altitudes, the C...

Time dependent Schrödinger equation for black hole evaporation: No information loss

DOE Office of Scientific and Technical Information (OSTI.GOV)

Corda, Christian, E-mail: cordac.galilei@gmail.com

2015-02-15

In 1976 S. Hawking claimed that “Because part of the information about the state of the system is lost down the hole, the final situation is represented by a density matrix rather than a pure quantum state”. This was the starting point of the popular “black hole (BH) information paradox”. In a series of papers, together with collaborators, we naturally interpreted BH quasi-normal modes (QNMs) in terms of quantum levels discussing a model of excited BH somewhat similar to the historical semi-classical Bohr model of the structure of a hydrogen atom. Here we explicitly write down, for the same model,more » a time dependent Schrödinger equation for the system composed by Hawking radiation and BH QNMs. The physical state and the correspondent wave function are written in terms of a unitary evolution matrix instead of a density matrix. Thus, the final state results to be a pure quantum state instead of a mixed one. Hence, Hawking’s claim is falsified because BHs result to be well defined quantum mechanical systems, having ordered, discrete quantum spectra, which respect ’t Hooft’s assumption that Schrödinger equations can be used universally for all dynamics in the universe. As a consequence, information comes out in BH evaporation in terms of pure states in a unitary time dependent evolution. In Section 4 of this paper we show that the present approach permits also to solve the entanglement problem connected with the information paradox.« less

Nonequilibrium radiation and dissociation of CO molecules in shock-heated flows

NASA Astrophysics Data System (ADS)

Macdonald, R. L.; Munafò, A.; Johnston, C. O.; Panesi, M.

2016-08-01

This work addresses the study of the behavior of the excited electronic states of CO molecules in the nonequilibrium relaxation zone behind a normal shock for a CO2-N2 mixture representative of the Mars atmosphere. The hybrid state-to-state (StS) model developed accounts for thermal nonequilibrium between the translational energy mode of the gas and the vibrational energy mode of individual molecules. The electronic states of CO molecules are treated as separate species, allowing for non-Boltzmann distributions of their populations. The StS model is coupled with a nonequilibrium radiation solver, hpc-rad, allowing for the calculation of the radiation signature from the molecular and atomic species in the gas. This study focuses on the radiation from the fourth positive system of CO, which dominates the radiation heating on the forebody for higher speed Mars entry applications. In the rapidly dissociating regime behind strong shock waves, the population of the ground electronic state of CO [ CO(X 1Σ )], departs from Maxwell-Boltzmann distributions, owing to the efficient collisional excitation to the electronically excited CO(A 1Π ) state. In general the assumption of the equilibrium between electronic and vibration fails when the excitation of electronic states is driven by heavy particles. The comparison of the radiation heating predictions obtained using the conventional quasi-steady-state (QSS) approach and the physics-based StS approach revealed differences in radiative heating predictions of up to 50%. These results demonstrate that the choice of nonequilibrium model can have a significant impact on radiative heating simulations, and more importantly, they cast serious doubts on the validity of the QSS assumption for the condition of interest to this work.

Nitric oxide excited under auroral conditions: Excited state densities and band emissions

NASA Astrophysics Data System (ADS)

Cartwright, D. C.; Brunger, M. J.; Campbell, L.; Mojarrabi, B.; Teubner, P. J. O.

2000-09-01

Electron impact excitation of vibrational levels in the ground electronic state and nine excited electronic states in NO has been simulated for an IBC II aurora (i.e., ˜10 kR in 3914 Å radiation) in order to predict NO excited state number densities and band emission intensities. New integral electron impact excitation cross sections for NO were combined with a measured IBC II auroral secondary electron distribution, and the vibrational populations of 10 NO electronic states were determined under conditions of statistical equilibrium. This model predicts an extended vibrational distribution in the NO ground electronic state produced by radiative cascade from the seven higher-lying doublet excited electronic states populated by electron impact. In addition to significant energy storage in vibrational excitation of the ground electronic state, both the a 4Π and L2 Φ excited electronic states are predicted to have relatively high number densities because they are only weakly connected to lower electronic states by radiative decay. Fundamental mode radiative transitions involving the lowest nine excited vibrational levels in the ground electronic state are predicted to produce infrared (IR) radiation from 5.33 to 6.05 μm with greater intensity than any single NO electronic emission band. Fundamental mode radiative transitions within the a 4Π electronic state, in the 10.08-11.37 μm region, are predicted to have IR intensities comparable to individual electronic emission bands in the Heath and ɛ band systems. Results from this model quantitatively predict the vibrational quantum number dependence of the NO IR measurements of Espy et al. [1988].

Examination of the low-energy enhancement of the γ -ray strength function of Fe 56

DOE PAGES

Jones, M. D.; Macchiavelli, A. O.; Wiedeking, M.; ...

2018-02-22

A model-independent technique was used to determine the γ-ray strength function (γSF) of 56Fe down to γ-ray energies less than 1 MeV for the first time with GRETINA using the (p,p') reaction at 16 MeV. No difference was observed in the energy dependence of the γSF built on 2 + and 4 + final states, supporting the Brink hypothesis. In addition, angular distribution and polarization measurements were performed. The angular distributions are consistent with dipole radiation. In conclusion, the polarization results show a small bias towards magnetic character in the region of the enhancement.

Examination of the low-energy enhancement of the γ -ray strength function of 56Fe

NASA Astrophysics Data System (ADS)

Jones, M. D.; Macchiavelli, A. O.; Wiedeking, M.; Bernstein, L. A.; Crawford, H. L.; Campbell, C. M.; Clark, R. M.; Cromaz, M.; Fallon, P.; Lee, I. Y.; Salathe, M.; Wiens, A.; Ayangeakaa, A. D.; Bleuel, D. L.; Bottoni, S.; Carpenter, M. P.; Davids, H. M.; Elson, J.; Görgen, A.; Guttormsen, M.; Janssens, R. V. F.; Kinnison, J. E.; Kirsch, L.; Larsen, A. C.; Lauritsen, T.; Reviol, W.; Sarantites, D. G.; Siem, S.; Voinov, A. V.; Zhu, S.

2018-02-01

A model-independent technique was used to determine the γ -ray strength function (γ SF ) of 56Fe down to γ -ray energies less than 1 MeV for the first time with GRETINA using the (p ,p') reaction at 16 MeV. No difference was observed in the energy dependence of the γ SF built on 2+ and 4+ final states, supporting the Brink hypothesis. In addition, angular distribution and polarization measurements were performed. The angular distributions are consistent with dipole radiation. The polarization results show a small bias towards magnetic character in the region of the enhancement.

Helicoidal graphene nanoribbons: Chiraltronics

DOE PAGES

Atanasov, Victor; Saxena, Avadh

2015-07-29

Here, we present a calculation of the effective geometry-induced quantum potential for the carriers in graphene shaped as a helicoidal nanoribbon. In this geometry the twist of the nanoribbon plays the role of an effective transverse electric field in graphene and this is reminiscent of the Hall effect. But, this effective electric field has a different sign for the two isospin states and translates into a mechanism to separate the two chiral species on the opposing rims of the nanoribbon. Finally, isospin transitions are expected with the emission or absorption of microwave radiation which could be adjusted to be inmore » the THz region.« less

KSC-98pc521

NASA Image and Video Library

1998-04-21

Processing activities for STS-91 continue in KSC's Orbiter Processing Facility Bay 2. Two Get Away Special (GAS) canisters are shown after their installation into Discovery's payload bay. At left is G-090, containing three educational experiments sponsored by Utah State University, and at right is G-743, an experiment sponsored by Broward Community College in Florida to test DNA exposed to cosmic radiation in a microgravity environment. STS-91 is scheduled to launch aboard the Space Shuttle Discovery for the ninth and final docking with the Russian Space Station Mir from KSC's Launch Pad 39A on June 2 with a launch window opening around 6:04 p.m. EDT

Modeling the Infrared Spectra of Earth-Analog Exoplanets

NASA Astrophysics Data System (ADS)

Nixon, C.

2014-04-01

As a preparation for future observations with the James Webb Space Telescope (JWST) and other facilities, we have undertaken to model the infrared spectra of Earth-like exoplanets. Two atmospheric models were used: the modern (low CO2) and archean (high CO2) predictive models of the Kasting group at Penn state. Several model parameters such as distance to star, and stellar type (visible-UV spectrum spectrum) were adjusted, and the models reconverged. Subsequently, the final model atmospheres were input to a radiative transfer code (NEMESIS) and the results intercompared to search for the most significant spectral changes. Implications for exoplanet spectrum detectivity will be discussed.

Multiquark production in p +A collisions: Quantum interference effects

NASA Astrophysics Data System (ADS)

Kovner, Alex; Rezaeian, Amir H.

2018-04-01

We consider forward inclusive production of several quarks in the high energy p -A collisions in the CGC formalism. For three particle production we provide a complete expression in terms of multipole scattering amplitudes on the nucleus and multiparticle generalized TMD's of the proton. We then calculate all the terms that are not suppressed by the factor of the area in four particle production, and generalize this result up to terms of order 1 /Nc2 for arbitrary number of produced particles. Our results include the contribution of quantum interference effects both in the final state radiation (HBT) and in the initial projectile wave function (Pauli blocking).

Examination of the low-energy enhancement of the γ -ray strength function of Fe 56

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, M. D.; Macchiavelli, A. O.; Wiedeking, M.

A model-independent technique was used to determine the γ-ray strength function (γSF) of 56Fe down to γ-ray energies less than 1 MeV for the first time with GRETINA using the (p,p') reaction at 16 MeV. No difference was observed in the energy dependence of the γSF built on 2 + and 4 + final states, supporting the Brink hypothesis. In addition, angular distribution and polarization measurements were performed. The angular distributions are consistent with dipole radiation. In conclusion, the polarization results show a small bias towards magnetic character in the region of the enhancement.

No firewalls in quantum gravity: the role of discreteness of quantum geometry in resolving the information loss paradox

NASA Astrophysics Data System (ADS)

Perez, Alejandro

2015-04-01

In an approach to quantum gravity where space-time arises from coarse graining of fundamentally discrete structures, black hole formation and subsequent evaporation can be described by a unitary evolution without the problems encountered by the standard remnant scenario or the schemes where information is assumed to come out with the radiation during evaporation (firewalls and complementarity). The final state is purified by correlations with the fundamental pre-geometric structures (in the sense of Wheeler), which are available in such approaches, and, like defects in the underlying space-time weave, can carry zero energy.

Black carbon radiative forcing at TOA decreased during aging.

PubMed

Wu, Yu; Cheng, Tianhai; Zheng, Lijuan; Chen, Hao

2016-12-05

During aging processing, black carbon (also called soot) particles may tend to be mixed with other aerosols, and highly influence their radiative forcing. In this study, freshly emitted soot particles were simulated as fractal aggregates composed of small spherical primary monomers. After aging in the atmosphere, soot monomers were coated by a thinly layer of sulfate as thinly coated soot particles. These soot particles were entirely embedded into large sulfate particle by further aging, and becoming heavily coated soot particles. In clear-sky conditions, black carbon radiative forcing with different aging states were investigated for the bottom and top of atmosphere (BOA and TOA). The simulations showed that black carbon radiative forcing increased at BOA and decreased at TOA after their aging processes. Thinly and heavily coated states increased up to ~12% and ~35% black carbon radiative forcing at BOA, and black carbon radiative forcing at TOA can reach to ~20% and ~100% smaller for thinly and heavily coated states than those of freshly emitted states, respectively. The effect of aging states of black carbon radiative forcing was varied with surface albedo, aerosol optical depth and solar zenith angles. These findings would be helpful for the assessments of climate change.

Ionizing Radiation Dose Due to the Use of Agricultural Fertilizers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Umisedo, Nancy K.; Okuno, Emico; Medina, Nilberto H.

2008-08-07

The transference of radionuclides from the fertilizers to/and from soils to the foodstuffs can represent an increment in the internal dose when the vegetables are consumed by the human beings. This work evaluates the contribution of fertilizers to the increase of radiation level in the environment and of dose to the people. Samples of fertilizers, soils and vegetables produced in farms located in the neighbourhood of Sao Paulo city in the State of Sao Paulo, Brazil were analysed through gamma spectroscopy. The values of specific activity of {sup 40}K, {sup 238}U and {sup 232}Th show that there is no significantmore » transference of natural radionuclides from fertilizers to the final product of the food chain. The annual committed effective dose due to the ingestion of {sup 40}K contained in the group of consumed vegetables analysed in this work resulted in the very low value of 0.882 {mu}Sv.« less

The RadioSat (sm) network

NASA Technical Reports Server (NTRS)

Noreen, Gary K.

1991-01-01

The RadioSat network under development by radio Satellite Corporation will use mobile satellite (MSAT) technology to provide diverse personal communications, broadcast, and navigation services. The network will support these services simultaneously for integrated mobile radios throughout Canada and the United States. The RadioSat network takes advantage of several technological breakthroughs, all coming to fruition by the time the first MSAT satellite is launched in 1994. The most important of these breakthroughs is the enormous radiated power of each MSAT spacecraft - orders of magnitude greater than the radiated power of previous L-band spacecraft. Another important breakthrough is the development of advanced digital audio compression algorithms, enabling the transmission of broadcast quality music at moderate data rates. Finally, continuing dramatic increases in VLSI capabilities permit the production of complex, multi-function mobile satellite radios in very large quantities at prices little more than those of conventional car radios. In addition to performance breakthroughs and their economic implications to RadioSat, the design of the RadioSat network is reviewed.

The Dynamical Dipole Radiation in Dissipative Collisions with Exotic Beams

NASA Astrophysics Data System (ADS)

di Toro, M.; Colonna, M.; Rizzo, C.; Baran, V.

Heavy Ion Collisions (HIC) represent a unique tool to probe the in-medium nuclear interaction in regions away from saturation. In this work we present a selection of reaction observables in dissipative collisions particularly sensitive to the isovector part of the interaction, i.e. to the symmetry term of the nuclear Equation of State (EoS). At low energies the behavior of the symmetry energy around saturation influences dissipation and fragment production mechanisms. We will first discuss the recently observed Dynamical Dipole Radiation, due to a collective neutron-proton oscillation during the charge equilibration in fusion and deep-inelastic collisions. We will review in detail all the main properties, yield, spectrum, damping and angular distributions, revealing important isospin effects. Reactions induced by unstable 132Sn beams appear to be very promising tools to test the sub-saturation Isovector EoS. Predictions are also presented for deep-inelastic and fragmentation collisions induced by neutron rich projectiles. The importance of studying violent collisions with radioactive beams at low and Fermi energies is finally stressed.

Lead exposure in radiator repair workers: a survey of Washington State radiator repair shops and review of occupational lead exposure registry data.

PubMed

Whittaker, Stephen G

2003-07-01

Radiator repair workers in Washington State have the greatest number of very elevated (> or =60 microg/dL) blood lead levels of any other worker population. The goals of this study were to determine the number of radiator repair workers potentially exposed to lead; estimate the extent of blood lead data underreporting to the Occupational Lead Exposure Registry; describe current safety and health practices in radiator repair shops; and determine appropriate intervention strategies to reduce exposure and increase employer and worker awareness. Lead exposure in Washington State's radiator repair workers was assessed by reviewing Registry data and conducting a statewide survey of radiator repair businesses. This study revealed that a total of 226 workers in Washington State (including owner-operators and all employees) conduct repair activities that could potentially result in excessive exposures to lead. Approximately 26% of radiator repair workers with elevated blood lead levels (> or =25 microg/dL) were determined to report to Washington State's Registry. This study also revealed a lack of awareness of lead's health effects, appropriate industrial hygiene controls, and the requirements of the Lead Standard. Survey respondents requested information on a variety of workplace health and safety issues and waste management; 80% requested a confidential, free-of-charge consultation. Combining data derived from an occupational health surveillance system and a statewide mail survey proved effective at characterizing lead exposures and directing public health intervention in Washington State.

Lévy noise improves the electrical activity in a neuron under electromagnetic radiation.

PubMed

Wu, Juan; Xu, Yong; Ma, Jun

2017-01-01

As the fluctuations of the internal bioelectricity of nervous system is various and complex, the external electromagnetic radiation induced by magnet flux on membrane can be described by the non-Gaussian type distribution of Lévy noise. Thus, the electrical activities in an improved Hindmarsh-Rose model excited by the external electromagnetic radiation of Lévy noise are investigated and some interesting modes of the electrical activities are exhibited. The external electromagnetic radiation of Lévy noise leads to the mode transition of the electrical activities and spatial phase, such as from the rest state to the firing state, from the spiking state to the spiking state with more spikes, and from the spiking state to the bursting state. Then the time points of the firing state versus Lévy noise intensity are depicted. The increasing of Lévy noise intensity heightens the neuron firing. Also the stationary probability distribution functions of the membrane potential of the neuron induced by the external electromagnetic radiation of Lévy noise with different intensity, stability index and skewness papremeters are analyzed. Moreover, through the positive largest Lyapunov exponent, the parameter regions of chaotic electrical mode of the neuron induced by the external electromagnetic radiation of Lévy noise distribution are detected.

Depopulation of metastable helium by radiative association with hydrogen and lithium ions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Augustovičová, L.; Soldán, P.; Kraemer, W. P., E-mail: pavel.soldan@mff.cuni.cz

2014-02-10

Depopulation of metastable He(2{sup 3}S) by radiative association with hydrogen and lithium ions is investigated using a fully quantal approach. Rate coefficients for spontaneous and stimulated radiative association of the HeH{sup +}, HeD{sup +}, and LiHe{sup +} molecular ions on the spin-triplet manifold are presented as functions of temperature considering the association to rotational-vibrational states of the lowest triplet electronic states a {sup 3}Σ{sup +} and b {sup 3}Σ{sup +} from the continuum states of the b {sup 3}Σ{sup +} electronic state. Evaluation of the rate coefficients is based on highly accurate quantum calculations, taking into account all possible state-to-statemore » transitions at thermal energies (for spontaneous association) or at higher background energies (stimulated association). As expected, calculations show that the rate coefficients for radiative association to the a state are several orders of magnitude larger than the one for the b state formation. A noticeable effect by blackbody background radiation on the radiative association is only obtained for the b → b process. Aspects of the formation and abundance of the metastable HeH{sup +}(a {sup 3}Σ{sup +}) in astrophysical environments are briefly discussed.« less

Lévy noise improves the electrical activity in a neuron under electromagnetic radiation

PubMed Central

Wu, Juan; Ma, Jun

2017-01-01

As the fluctuations of the internal bioelectricity of nervous system is various and complex, the external electromagnetic radiation induced by magnet flux on membrane can be described by the non-Gaussian type distribution of Lévy noise. Thus, the electrical activities in an improved Hindmarsh-Rose model excited by the external electromagnetic radiation of Lévy noise are investigated and some interesting modes of the electrical activities are exhibited. The external electromagnetic radiation of Lévy noise leads to the mode transition of the electrical activities and spatial phase, such as from the rest state to the firing state, from the spiking state to the spiking state with more spikes, and from the spiking state to the bursting state. Then the time points of the firing state versus Lévy noise intensity are depicted. The increasing of Lévy noise intensity heightens the neuron firing. Also the stationary probability distribution functions of the membrane potential of the neuron induced by the external electromagnetic radiation of Lévy noise with different intensity, stability index and skewness papremeters are analyzed. Moreover, through the positive largest Lyapunov exponent, the parameter regions of chaotic electrical mode of the neuron induced by the external electromagnetic radiation of Lévy noise distribution are detected. PMID:28358824

The cyclotron maser theory of AKR and Z-mode radiation. [Auroral Kilometric Radiation

NASA Technical Reports Server (NTRS)

Wu, C. S.

1985-01-01

The cyclotron maser mechanism which may be responsible for the generation of auroral kilometric radiation and Z-mode radiation is discussed. Emphasis is placed on the basic concepts of the cyclotron maser theory, particularly the relativistic effect of the cyclotron resonance condition. Recent development of the theory is reviewed. Finally, the results of a computer simulation study which helps to understand the nonlinear saturation of the maser instability are reported.

πN scattering and γN → Nπ photoproduction within the unitary improved Born approximation

NASA Astrophysics Data System (ADS)

Mariano, A.

2007-07-01

Following the programme of describing consistently several processes where the isobar Δ(1232 MeV) nucleon resonance appears as an intermediate state, in this work we propose to unitarize our old improved Born approximation already used to describe successfully π+p elastic and radiative scattering, to treat pion photoproduction. First we add the effect of final state interactions and make a new determination of the mass, width and the coupling constant to the pion-nucleon state of the Δ resonance. Then extending the model for pion photoproduction and using the resonance parameters determined previously, we are able to define effective form factors (at k2γ = 0) for the γN → Δ vertex with values GM = 2.97 ± 0.08 and GE = 0.055 ± 0.010, by fitting the data for the M3/21+ and E3/21+ multipoles. These values are fully consistent with recent chiral effective field theory calculations, and using them we can predict satisfactorily the data for other multipoles and the photoproduction cross section. Finally, we intend a model-independent determination of the bare form factors making a dynamical dressing of the vertex, getting G0M = 1.69 ± 0.02, G0E = 0.028 ± 0.008 and R0EM = -1.67 ± 0.45%, which are compared with different quark models.

Assurance Against Radiation Effects on Electronics

NASA Technical Reports Server (NTRS)

LaBel, Kenneth A.

2004-01-01

Contents include the following: The Space Radiation Environment. The Effects on Electronics. The Environment in Action. NASA Approaches to Commercial Electronics: the mission mix, flight projects, and proactive research. Final Thoughts: atomic interactions, direct ionization, interaction with nucleus.

Base-level management of radio-frequency radiation-protection program. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rademacher, S.E.; Montgomery, N.D.

1989-04-01

AFOEHL developed this report to assist the base-level aerospace medical team manage their radio-frequency radiation-protection program. This report supersedes USAFOEHL Report 80-42, 'A Practical R-F Guide for BEES.'

Base-level management of radio-frequency radiation-protection program. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rademacher, S.E.; Montgomery, N.D.

1989-04-01

AFOEHL developed this report to assist the base-level aerospace medical team manage their radio-frequency radiation protection program. This report supersedes USAFOEHL Report 80-42, 'A practical R-F Guide for BEES.'

Rare Event Simulation in Radiation Transport

NASA Astrophysics Data System (ADS)

Kollman, Craig

This dissertation studies methods for estimating extremely small probabilities by Monte Carlo simulation. Problems in radiation transport typically involve estimating very rare events or the expected value of a random variable which is with overwhelming probability equal to zero. These problems often have high dimensional state spaces and irregular geometries so that analytic solutions are not possible. Monte Carlo simulation must be used to estimate the radiation dosage being transported to a particular location. If the area is well shielded the probability of any one particular particle getting through is very small. Because of the large number of particles involved, even a tiny fraction penetrating the shield may represent an unacceptable level of radiation. It therefore becomes critical to be able to accurately estimate this extremely small probability. Importance sampling is a well known technique for improving the efficiency of rare event calculations. Here, a new set of probabilities is used in the simulation runs. The results are multiplied by the likelihood ratio between the true and simulated probabilities so as to keep our estimator unbiased. The variance of the resulting estimator is very sensitive to which new set of transition probabilities are chosen. It is shown that a zero variance estimator does exist, but that its computation requires exact knowledge of the solution. A simple random walk with an associated killing model for the scatter of neutrons is introduced. Large deviation results for optimal importance sampling in random walks are extended to the case where killing is present. An adaptive "learning" algorithm for implementing importance sampling is given for more general Markov chain models of neutron scatter. For finite state spaces this algorithm is shown to give, with probability one, a sequence of estimates converging exponentially fast to the true solution. In the final chapter, an attempt to generalize this algorithm to a continuous state space is made. This involves partitioning the space into a finite number of cells. There is a tradeoff between additional computation per iteration and variance reduction per iteration that arises in determining the optimal grid size. All versions of this algorithm can be thought of as a compromise between deterministic and Monte Carlo methods, capturing advantages of both techniques.

Horizon state, Hawking radiation, and boundary Liouville model.

PubMed

Solodukhin, Sergey N

2004-02-13

We demonstrate that the near-horizon physics, the Hawking radiation, and the reflection off the radial potential barrier can be understood entirely within a conformal field theory picture in terms of one- and two-point functions in the boundary Liouville theory. An important element in this demonstration is the notion of horizon state, the Hawking radiation being interpreted as a result of the transition of horizon state to the ordinary states propagating outside the black hole horizon.

Situational awareness of hazards: Validation of multi-source radiation measurements

NASA Astrophysics Data System (ADS)

Hultquist, C.; Cervone, G.

2016-12-01

Citizen-led movements producing scientific hazard data during disasters are increasingly common. After the Japanese earthquake-triggered tsunami in 2011, and the resulting radioactive releases at the damaged Fukushima Daiichi nuclear power plants, citizens monitored on-ground levels of radiation with innovative mobile devices built from off-the-shelf components. To date, the citizen-led SAFECAST project has recorded 50 million radiation measurements worldwide, with the majority of these measurements from Japan. The analysis of data which are multi-dimensional, not vetted, and provided from multiple devices presents big data challenges due to their volume, velocity, variety, and veracity. While the SAFECAST project produced massive open-source radiation measurements at specific coordinates and times, the reliability and validity of the overall data have not yet been assessed. The nuclear disaster provides a case for assessing the SAFECAST data with official aerial remote sensing radiation data jointly collected by the governments of the United States and Japan. A spatial and statistical assessment of SAFECAST requires several preprocessing steps. First, SAFECAST ionized radiation sensors collected data using different units of measure than the government data, and they had to be converted. Secondly, the normally occurring radiation and decay rates of Cesium from deposition surveys were used to properly compare measurements in space and time. Finally, the GPS located points were selected within overlapping extents at multiple spatial resolutions. Quantitative measures were used to assess the similarity and differences in the observed measurements. Radiation measurements from the same geographic extents show similar spatial variations and statistically significant correlations. The results suggest that actionable scientific data for disasters and emergencies can be inferred from non-traditional and not vetted data generated through citizen science projects. This project provides a methodology for comparing datasets of radiological measurements over time and space. Integrating data for assessment from different Earth sensing systems is paramount for societal and environmental problems.

Radiation from an accelerating neutral body: The case of rotation

NASA Astrophysics Data System (ADS)

Yarman, Tolga; Arik, Metin; Kholmetskii, Alexander L.

2013-11-01

When an object is bound at rest to an attractional field, its rest mass (owing to the law of energy conservation, including the mass and energy equivalence of the Special Theory of Relativity) must decrease. The mass deficiency coming into play indicates a corresponding rest energy discharge. Thus, bringing an object to a rotational motion means that the energy transferred for this purpose serves to extract just as much rest mass (or similarly "rest energy", were the speed of light in empty space taken to be unity) out of it. Here, it is shown that during angular acceleration, photons of fundamental energy are emitted, while the object is kept on being delivered to a more and more intense rotational accelerational field, being the instantaneous angular velocity of the rotating object. This fundamental energy, as seen, does not depend on anything else (such as the mass or charge of the object), and it is in harmony with Bohr's Principle of Correspondence. This means at the same time, that emission will be achieved, as long as the angular velocity keeps on increasing, and will cease right after the object reaches a stationary rotational motion (a constant centrifugal acceleration), but if the object were brought to rotation in vacuum with no friction. By the same token, one can affirm that even the rotation at a macroscopic level is quantized, and can only take on "given angular velocities" (which can only be increased, bit by bit). The rate of emission of photons of concern is, on the other hand, proportional to the angular acceleration of the object, similarly to the derivative of the tangential acceleration with respect to time. It is thus constant for a "constant angular acceleration", although the energy of the emitted photons will increase with increasing , until the rotation reaches a stationary level, after which we expect no emission --let us stress-- if the object is in rotation in vacuum, along with no whatsoever friction (such as the case of a rotating diatomic molecule, for instance). If the object reaches its final state in a given medium, say air, and "friction" is present, such as the case of a dental drill, then energy should keep being supplied to it, to overcome friction, which is present either inside the "inner mechanism of rotation" or in its surroundings. In other words, the object in the latter case, would be constantly subject to a friction force, countering its motion, and tending to make it fall to lower rotational energy states. Any fluctuations in the power supply, on the other hand, will slow down the rotating object, no matter how indiscernibly. The small decrease in the rotational velocity is yet reincreased by restoring the power supply, thus perpetually securing a stationary rotational motion. Thereby, the object in this final state, due to fluctuations in either friction or power supply, or both, shall further be expected to emit a radiation of energy , where is the final angular velocity of the object in rotation. What is more is that our team has very successfully measured what is predicted here, and they will report their experimental results in a subsequent article. The approach presented here seems to shed light on the mysterious sonoluminescence. It also triggers the possibility of sensing earthquakes due to radiation that should be emitted by the faults, on which the seismic stress keeps increasing until the crackdown. By the same token, also two colliding (neutral) objects are expected to emit radiation.

Cosmic Radiation | RadTown USA | US EPA

EPA Pesticide Factsheets

2017-08-07

Radiation from space is constantly hitting the Earth. Radiation from space is called cosmic radiation. Cosmic radiation makes up about five percent of annual radiation exposure of an average person in the United States.

A Hybrid Model for Multiscale Laser Plasma Simulations with Detailed Collisional Physics

DTIC Science & Technology

2017-06-15

Validation against experimental data •Nonequilibrium radiation transport: coupling with a collisional-radiative model •Inelastic collisions in a MF...for Public Release; Distribution is Unlimited. PA# 17383 Collisional Radiative (CR) Overview Updates • Investigated Quasi -Steady-State • Investigated...Techniques Quasi Stead-State (QSS) • Assumes fast kinetics between states within an ion distribution • Assumes longer diffusion/decay times than

Reconstructing WIMP properties through an interplay of signal measurements in direct detection, Fermi-LAT, and CTA searches for dark matter

NASA Astrophysics Data System (ADS)

Roszkowski, Leszek; Sessolo, Enrico Maria; Trojanowski, Sebastian; Williams, Andrew J.

2016-08-01

We examine the projected ability to reconstruct the mass, scattering, and annihilation cross section of dark matter in the new generation of large underground detectors, XENON-1T, SuperCDMS, and DarkSide-G2, in combination with diffuse gamma radiation from expected 15 years of data from Fermi-LAT observation of 46 local spiral dwarf galaxies and projected CTA sensitivity to a signal from the Galactic Center. To this end we consider several benchmark points spanning a wide range of WIMP mass, different annihilation final states, and large enough event rates to warrant detection in one or more experiments. As previously shown, below some 100 GeV only direct detection experiments will in principle be able to reconstruct WIMP mass well. This may, in case a signal at Fermi-LAT is also detected, additionally help restricting σv and the allowed decay branching rates. In the intermediate range between some 100 GeV and up a few hundred GeV, direct and indirect detection experiments can be used in complementarity to ameliorate the respective determinations, which in individual experiments can at best be rather poor, thus making the WIMP reconstruction in this mass range very challenging. At large WIMP mass, ~ 1 TeV, CTA will have the ability to reconstruct mass, annihilation cross section, and the allowed decay branching rates to very good precision for the τ+τ- or purely leptonic final state, good for the W+W- case, and rather poor for bbar b. A substantial improvement can potentially be achieved by reducing the systematic uncertainties, increasing exposure, or by an additional measurement at Fermi-LAT that would help reconstruct the annihilation cross section and the allowed branching fractions to different final states.

Electroweak Boson Production in Association with Jets

NASA Astrophysics Data System (ADS)

Focke, Christfried Hermann

The high energies involved in modern collider experiments lead to hadronic final states that are often boosted inside collimated jets and surrounded by soft radiation. Together with tracking and energy information from leptons and photons, these jets contain essential information about a collision event. A good theoretical understanding is vital for measurements within the Standard Model (SM) as well as for background modeling required for new physics searches. Often one is interested in hadronic final states with cuts on jets in order to reduce backgrounds. For example, by imposing a central jet veto pcut in H → WW → lnulnu one can greatly reduce contamination from tt¯ → WW bb¯. Imposing such a jet veto comes at the cost of introducing potentially large logarithms L = ln pcut/Q into the cross section (Q is the hard scale), since the cuts restrict the cancellation of soft and collinear divergences between real and virtual diagrams. There are at most two powers of L for each power of the strong coupling constant alphas and this can spoil the convergence of the perturbative series when alpha sL2 ˜ 1 . We resume these logarithmically enhanced terms to all orders within the framework of Soft-Collinear Effective Theory (SCET) in order to recover the convergence and obtain reliable predictions for several processes. Another focus of this dissertation is the application of SCET in fixed order predictions of electroweak boson production in association with an exclusive number of final state jets. We employ the N-jettiness event-shape TN to resolve the infrared singularity structure of QCD in the presence of N signal jets. This allows us to obtain the first complete next-to-next-to leading order predictions for W, Z and Higgs boson production in association with one jet.

Survey of application of radiation to preparative chemistry

NASA Technical Reports Server (NTRS)

Philipp, W. H.

1973-01-01

The use of radiation for preparative chemistry in liquid solutions is investigated. General principles are presented and preparations involving reduction, oxidation, polymerization, and decomposition are given. The use of various solvents, water, other inorganic liquids and organic liquids for this purpose is discussed. Finally, a commentary is made on some specific applications where radiation chemistry as a preparative technique may be useful.

Effect of Long Term Low-Level Gamma Radiation on Thermal Sensitivity of RDX/HMX Mixtures

DTIC Science & Technology

1976-11-01

1.1x10 R. It was concluded that the slight exothermic reaction before the 3^6 HMX polymorphic transition could be caused by a radiation-induced...Radiation on Thermal Sensitivity of RDX / HMX Mixtures 5. TYPE OF REPORT 4 PERIOD COVERED Final Report 6. PERFORMING ORG. REPORT NUMBER 7...and Identity by block number) Gamma radiation Weight loss HMX Impact sensitivity test RDX Vacuum stability test DTA Infrared spectrometry TGA

RHOBOT: Radiation hardened robotics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bennett, P.C.; Posey, L.D.

1997-10-01

A survey of robotic applications in radioactive environments has been conducted, and analysis of robotic system components and their response to the varying types and strengths of radiation has been completed. Two specific robotic systems for accident recovery and nuclear fuel movement have been analyzed in detail for radiation hardness. Finally, a general design approach for radiation-hardened robotics systems has been developed and is presented. This report completes this project which was funded under the Laboratory Directed Research and Development program.

On the radiative effects of light-absorbing impurities on snowpack evolution

NASA Astrophysics Data System (ADS)

Dumont, M.; Tuzet, F.; Lafaysse, M.; Arnaud, L.; Picard, G.; Lejeune, Y.; Lamare, M.; Morin, S.; Voisin, D.; Di Mauro, B.

2017-12-01

The presence of light absorbing impurities in snow strongly decreases snow reflectance leading to an increase in the amount of solar energy absorbed by the snowpack. This effect is also known as impurities direct radiative effect. The change in the amount of energy absorbed by the snowpack modifies the temperature profile inside the snowpack and in turn snow metamorphism (impurities indirect radiative effects). In this work, we used the detailed snowpack model SURFEX/ISBA-Crocus with an explicit representation of snow light-absorbing impurities content (Tuzet et al., 2017) fed by medium-resolution ALADIN-Climate atmospheric model to represent dust and black carbon atmospheric deposition fluxes. The model is used at two sites: Col de Porte (medium elevation site in the French Alps) and Torgnon (high elevation site in the Italian Alps). The simulations are compared to in-situ observations and used to quantify the effects of light-absorbing impurities on snow melt rate and timing. The respective parts of the direct and indirect radiative effects of light-absorbing impurities in snow are also computed for the two sites, emphasizing the need to account for the interactions between snow metamorphism and LAI radiative properties, to accurately predict the effects of light-absorbing impurities in snow. Moreover, we describe how automated hyperspectral reflectance can be used to estimate effective impurities surface content in snow. Finally we demonstrate how these reflectances measurements either from in situ or satellite data can be used via an assimilation scheme to constrain snowpack ensemble simulations and better predict the snowpack state and evolution.

Optical Radiation from Integer Quantum Hall States in Dirac Materials

NASA Astrophysics Data System (ADS)

Gullans, Michael; Taylor, Jacob; Ghaemi, Pouyan; Hafezi, Mohammad

Quantum Hall systems exhibit topologically protected edge states, which can have a macroscopic spatial extent. Such edge states provide a unique opportunity to study a quantum emitter whose size far exceeds the wavelength of emitted light. To better understand this limit, we theoretically characterize the optical radiation from integer quantum Hall states in two-dimensional Dirac materials. We show that the scattered light from the bulk reflects the spatial profile of the wavefunctions, enabling spatial imaging of the disorder landscape. We find that the radiation from the edge states are characterized by the presence of large multipole moments in the far-field. This multipole radiation arises from the transfer of angular momentum from the electrons into the scattered light, enabling the generation of coherent light with high orbital angular momentum.

76 FR 62306 - Countermeasures Injury Compensation Program (CICP): Administrative Implementation, Final Rule

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-07

... respirators, Respiratory support devices, Ventilators, Anthrax, Smallpox, Botulism, Acute radiation syndrome...] and Relenza[supreg] when used for pandemic purposes; (5) smallpox countermeasures; (6) acute radiation syndrome countermeasures; (7) pandemic influenza diagnostics, personal respiratory devices, and respiratory...

LDRD Final Review: Radiation Transport Calculations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Goorley, John Timothy; Morgan, George Lake; Lestone, John Paul

2017-06-22

Both high-fidelity & toy simulations are being used to understand measured signals and improve the Area 11 NDSE diagnostic. We continue to gain more and more confidence in the ability for MCNP to simulate neutron and photon transport from source to radiation detector.

Paediatric x-ray radiation dose reduction and image quality analysis.

PubMed

Martin, L; Ruddlesden, R; Makepeace, C; Robinson, L; Mistry, T; Starritt, H

2013-09-01

Collaboration of multiple staff groups has resulted in significant reduction in the risk of radiation-induced cancer from radiographic x-ray exposure during childhood. In this study at an acute NHS hospital trust, a preliminary audit identified initial exposure factors. These were compared with European and UK guidance, leading to the introduction of new factors that were in compliance with European guidance on x-ray tube potentials. Image quality was assessed using standard anatomical criteria scoring, and visual grading characteristics analysis assessed the impact on image quality of changes in exposure factors. This analysis determined the acceptability of gradual radiation dose reduction below the European and UK guidance levels. Chest and pelvis exposures were optimised, achieving dose reduction for each age group, with 7%-55% decrease in critical organ dose. Clinicians confirmed diagnostic image quality throughout the iterative process. Analysis of images acquired with preliminary and final exposure factors indicated an average visual grading analysis result of 0.5, demonstrating equivalent image quality. The optimisation process and final radiation doses are reported for Carestream computed radiography to aid other hospitals in minimising radiation risks to children.

FY06 LDRD Final Report: Broadband Radiation and Scattering

DOE Office of Scientific and Technical Information (OSTI.GOV)

Madsen, N; Fasenfest, B; White, D

2007-03-08

This is the final report for LDRD 01-ERD-005. The Principle Investigator was Robert Sharpe. Collaborators included Niel Madsen, Benjamin Fasenfest, John D. Rockway, of the Defense Sciences Engineering Division (DSED), Vikram Jandhyala and James Pingenot from the University of Washington, and Mark Stowell of the Center for Applications Development and Software Engineering (CADSE). It should be noted that Benjamin Fasenfest and Mark Stowell were partially supported under other funding. The purpose of this LDRD effort was to enhance LLNL's computational electromagnetics capability in the area of broadband radiation and scattering. For radiation and scattering problems our transient EM codes aremore » limited by the approximate Radiation Boundary Conditions (RBC's) used to model the radiation into an infinite space. Improved RBC's were researched, developed, and incorporated into the existing EMSolve finite-element code to provide a 10-100x improvement in the accuracy of the boundary conditions. Section I provides an introduction to the project and the project goals. Section II provides a summary of the project's research and accomplishments as presented in the attached papers.« less

X-ray scattering measurements on imploding CH spheres at the National Ignition Facility

DOE PAGES

Kraus, D.; Chapman, D. A.; Kritcher, A. L.; ...

2016-07-21

In this study, we have performed spectrally resolved x-ray scattering measurements on highly compressed polystyrene at pressures of several tens of TPa (100 Mbar) created by spherically convergent shocks at the National Ignition Facility. Scattering data of line radiation at 9.0 keV were recorded from the dense plasma shortly after shock coalescence. Accounting for spatial gradients, opacity effects, and source broadening, we demonstrate the sensitivity of the elastic scattering component to carbon K -shell ionization while at the same time constraining the temperature of the dense plasma. Finally, for six times compressed polystyrene, we find an average temperature of 86more » eV and carbon ionization state of 4.9, indicating that widely used ionization models need revision in order to be suitable for the extreme states of matter tested in our experiment.« less

Magnetic field effect on photoionization cross-section of hydrogen-like impurity in cylindrical quantum wire

NASA Astrophysics Data System (ADS)

Mughnetsyan, V. N.; Barseghyan, M. G.; Kirakosyan, A. A.

2008-01-01

We consider the photoionization of a hydrogen-like impurity centre in a quantum wire approximated by a cylindrical well of finite depth in a magnetic field directed along the wire axis. The ground state energy and the wave function of the electron localized on on-axis impurity centre are calculated using the variational method. The wave functions and energies of the final states in an one-dimensional conduction subband are also presented. The dependences of photoionization cross-section of a donor centre on magnetic field and frequency of incident radiation both for parallel and perpendicular polarizations and corresponding selection rules for the allowed transitions are found in the dipole approximation. The estimates of photoionization cross-section for various values of wire radius and magnetic field induction for GaAs quantum wire embedded in Ga 1-xAl 1-xAs matrix are given.

Observation of {chi}{sub cJ} Radiative Decays to Light Vector Mesons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bennett, J. V.; Mitchell, R. E.; Shepherd, M. R.

2008-10-10

Using a total of 2.74x10{sup 7} decays of the {psi}(2S) collected with the CLEO-c detector, we present a study of {chi}{sub cJ}{yields}{gamma}V, where V={rho}{sup 0}, {omega}, {phi}. The transitions {chi}{sub c1}{yields}{gamma}{rho}{sup 0} and {chi}{sub c1}{yields}{gamma}{omega} are observed with B({chi}{sub c1}{yields}{gamma}{rho}{sup 0})=(2.43{+-}0.19{+-}0.22)x10{sup -4} and B({chi}{sub c1}{yields}{gamma}{omega})=(8.3{+-}1.5{+-}1.2)x10{sup -5}. In the {chi}{sub c1}{yields}{gamma}{rho}{sup 0} transition, the final state meson is dominantly longitudinally polarized. Upper limits on the branching fractions of other {chi}{sub cJ} states to light vector mesons are presented.

Mixing states of aerosols over four environmentally distinct atmospheric regimes in Asia: coastal, urban, and industrial locations influenced by dust.

PubMed

Ramachandran, S; Srivastava, Rohit

2016-06-01

Mixing can influence the optical, physical, and chemical characteristics of aerosols, which in turn can modify their life cycle and radiative effects. Assumptions on the mixing state can lead to uncertain estimates of aerosol radiative effects. To examine the effect of mixing on the aerosol characteristics, and their influence on radiative effects, aerosol mixing states are determined over four environmentally distinct locations (Karachi, Gwangju, Osaka, and Singapore) in Asia, an aerosol hot spot region, using measured spectral aerosol optical properties and optical properties model. Aerosol optical depth (AOD), single scattering albedo (SSA), and asymmetry parameter (g) exhibit spectral, spatial, and temporal variations. Aerosol mixing states exhibit large spatial and temporal variations consistent with aerosol characteristics and aerosol type over each location. External mixing of aerosol species is unable to reproduce measured SSA over Asia, thus providing a strong evidence that aerosols exist in mixed state. Mineral dust (MD) (core)-Black carbon (BC) (shell) is one of the most preferred aerosol mixing states. Over locations influenced by biomass burning aerosols, BC (core)-water soluble (WS, shell) is a preferred mixing state, while dust gets coated by anthropogenic aerosols (BC, WS) over urban regions influenced by dust. MD (core)-sea salt (shell) mixing is found over Gwangju corroborating the observations. Aerosol radiative forcing exhibits large seasonal and spatial variations consistent with features seen in aerosol optical properties and mixing states. TOA forcing is less negative/positive for external mixing scenario because of lower SSA. Aerosol radiative forcing in Karachi is a factor of 2 higher when compared to Gwangju, Osaka, and Singapore. The influence of g on aerosol radiative forcing is insignificant. Results emphasize that rather than prescribing one single aerosol mixing state in global climate models regionally and temporally varying aerosol mixing states should be included for more accurate assessment of aerosol radiative effects.

Low-Power Multi-Aspect Space Radiation Detector System

NASA Technical Reports Server (NTRS)

Wrbanek, John D.; Wrbanek, Susan Y.; Fralick, Gustave; Freeman, Jon C.; Burkebile, Stephen P.

2012-01-01

The advanced space radiation detector development team at NASA Glenn Research Center (GRC) has the goal of developing unique, more compact radiation detectors that provide improved real-time data on space radiation. The team has performed studies of different detector designs using a variety of combinations of solid-state detectors, which allow higher sensitivity to radiation in a smaller package and operate at lower voltage than traditional detectors. Integration of all of these detector technologies will result in an improved detector system in comparison to existing state-of-the-art (SOA) instruments for the detection and monitoring of the deep space radiation field.

EFFECTS OF LASER RADIATION ON MATTER: Spectrum of the barium atom in a laser radiation field

NASA Astrophysics Data System (ADS)

Bondar', I. I.; Suran, V. V.

1990-08-01

An experimental investigation was made of the influence of a laser radiation field on the spectrum of barium atoms. The investigation was carried out by the method of three-photon ionization spectroscopy using dye laser radiation (ω = 14 800-18 700 cm - 1). The electric field intensity of the laser radiation was 103-106 V/cm. This laser radiation field had a strong influence on a number of bound and autoionizing states. The nature of this influence depended on the ratio of the excitation frequencies of bound and autoionizing states.

Final Report for Research Conducted at The Scripps Institution of Oceanography, University of California San Diego from 2/2002 to 8/2003 for ''Aerosol and Cloud-Field Radiative Effects in the Tropical Western Pacific: Analyses and General Circulation Model Parameterizations''

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vogelmann, A. M.

OAK-B135 Final report from the University of California San Diego for an ongoing research project that was moved to Brookhaven National Laboratory where proposed work will be completed. The research uses measurements made by the Atmospheric Radiation Measurement (ARM) Program to quantify the effects of aerosols and clouds on the Earth's energy balance in the climatically important Tropical Western Pacific.

EFFECTS OF IONIZING RADIATION IN CHIMPANZEES. Final Report, February 28, 1962-October 31, 1962

DOE Office of Scientific and Technical Information (OSTI.GOV)

Riopelle, A.J.; Rogers, C.M.

1963-10-31

Results are reported from studies of the psychological, hematological, and pathological effects of a second dose of radiation to a group of chimpanzees irradiated several years before. The effects of a large dose of radiation to the head alone on previously nonirradiated animals were evaluated in 4 animals. Findings are summarized for each animal. No evidence of damage to neural tissue was seen following exposure to the head to 2000 r gamma radiation. (C.H.)

Radiative Penguin Decays at the B Factories

DOE Office of Scientific and Technical Information (OSTI.GOV)

Koneke, Karsten; /MIT, LNS

2007-11-16

In this article, I review the most recent results in radiative penguin decays from the B factories Belle and BABAR. Most notably, I will talk about the recent new observations in the decays B {yields} ({rho}/{omega}) {gamma}, a new analysis technique in b {yields} s{gamma}, and first measurements of radiative penguin decays in the B{sup 0}{sub s} meson system. Finally, I will summarize the current status and future prospects of radiative penguin B physics at the B factories.

Radiation balances and the solar constant

NASA Technical Reports Server (NTRS)

Crommelynck, D.

1981-01-01

The radiometric concepts are defined in order to consider various types of radiation balances and relate them to the diabetic form of the energy balance. Variability in space and time of the components of the radiation field are presented. A specific concept for sweeping which is tailored to the requirements is proposed. Finally, after establishing the truncated character of the present knowledge of the radiation balance. The results of the last observations of the solar constant are given. Ground and satellite measurement techniques are discussed.

Results of the 2013-2015 Association of Residents in Radiation Oncology Survey of Chief Residents in the United States

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nabavizadeh, Nima, E-mail: nabaviza@ohsu.edu; Burt, Lindsay M.; Mancini, Brandon R.

Purpose: The purpose of this project was to survey radiation oncology chief residents to define their residency experience and readiness for independent practice. Methods and Materials: During the academic years 2013 to 2014 and 2014 to 2015, the Association of Residents in Radiation Oncology (ARRO) conducted an electronic survey of post-graduate year-5 radiation oncology residents in the United States during the final 3 months of training. Descriptive statistics are reported. Results: Sixty-six chief residents completed the survey in 2013 to 2014 (53% response rate), and 69 completed the survey in 2014 to 2015 (64% response rate). Forty to 85% percent ofmore » residents reported inadequate exposure to high-dose rate and low-dose rate brachytherapy. Nearly all residents in both years (>90%) reported adequate clinical experience for the following disease sites: breast, central nervous system, gastrointestinal, genitourinary, head and neck, and lung. However, as few as 56% reported adequate experience in lymphoma or pediatric malignancies. More than 90% of residents had participated in retrospective research projects, with 20% conducting resident-led prospective clinical trials and 50% conducting basic science or translational projects. Most chief residents reported working 60 or fewer hours per week in the clinical/hospital setting and performing fewer than 15 hours per week tasks that were considered to have little or no educational value. There was more than 80% compliance with Accreditation Council for Graduate Medical Education (ACGME) work hour limits. Fifty-five percent of graduating residents intended to join an established private practice group, compared to 25% who headed for academia. Residents perceive the job market to be more competitive than previous years. Conclusions: This first update of the ARRO chief resident survey since the 2007 to 2008 academic year documents US radiation oncology residents' experiences and conditions over a 2-year period. This analysis may serve as a valuable tool for those seeking to improve training of the next generation of oncology leaders.« less

Thermodynamics of radiation induced amorphization and thermal annealing of Dy 2Sn 2O 7 pyrochlore

DOE PAGES

Chung, Cheng-Kai; Lang, Maik; Xu, Hongwu; ...

2018-06-14

Thermodynamics and annealing behavior of swift heavy ion amorphized Dy 2Sn 2O 7 pyrochlore were studied. Its amorphization enthalpy, defined as the total energetic difference between the irradiation amorphized and undamaged Dy 2Sn 2O 7 states, was determined to be 283.6 ± 6.5 kJ/mol by high temperature oxide melt drop solution calorimetry. It has been an enigma that stannate and some other pyrochlores do not follow the general r A/r B-radiation resistance relation seen in most pyrochlore systems. In this paper, we use the amorphization enthalpy, which reflects all the complex chemical and structural characteristics, as a more effective parametermore » to correlate the radiation damage resistance of pyrochlores with their compositions. It successfully explains the superior radiation damage resistance of the stannate pyrochlores compared with titanate pyrochlores. Differential scanning calorimetry (DSC) reveals a strong exothermic event starting at 978 K, which is attributed to long-range recrystallization based on X-ray diffraction (XRD) analysis, similar to the effect previously observed in Dy 2Ti 2O 7. A second pronounced heat event beginning at ~1148 K, which results from local structural rearrangement, is clearly decoupled from the first event for irradiated Dy 2Sn 2O 7. Both the heat releases measured by DSC on heating to 1023 and 1473 K, and the excess enthalpies of the annealed samples indicate that the recovery to the original, ordered state was not fully achieved up to even 1473 K, despite XRD showing the apparent restoration of crystalline pyrochlore structure. The remaining metastability may be attributed to local disorder in the form of weberite-like short-range domains in the recrystallized material. Intriguingly, the second event for different pyrochlores generally starts at similar temperatures while the onset of the long range recrystallization is compositionally dependent. Finally, the amorphization and thermal annealing behavior observed in irradiated Dy 2Sn 2O 7 may provide insights into the general mechanisms of radiation damage and recovery of pyrochlores relevant to their nuclear applications.« less

Cellular telephone-based radiation sensor and wide-area detection network

DOEpatents

Craig, William W [Pittsburg, CA; Labov, Simon E [Berkeley, CA

2006-12-12

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

Cellular telephone-based radiation detection instrument

DOEpatents

Craig, William W [Pittsburg, CA; Labov, Simon E [Berkeley, CA

2011-06-14

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

Cellular telephone-based wide-area radiation detection network

DOEpatents

Craig, William W [Pittsburg, CA; Labov, Simon E [Berkeley, CA

2009-06-09

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

Applications of Machine Learning for Radiation Therapy.

PubMed

Arimura, Hidetaka; Nakamoto, Takahiro

2016-01-01

Radiation therapy has been highly advanced as image guided radiation therapy (IGRT) by making advantage of image engineering technologies. Recently, novel frameworks based on image engineering technologies as well as machine learning technologies have been studied for sophisticating the radiation therapy. In this review paper, the author introduces several researches of applications of machine learning for radiation therapy. For examples, a method to determine the threshold values for standardized uptake value (SUV) for estimation of gross tumor volume (GTV) in positron emission tomography (PET) images, an approach to estimate the multileaf collimator (MLC) position errors between treatment plans and radiation delivery time, and prediction frameworks for esophageal stenosis and radiation pneumonitis risk after radiation therapy are described. Finally, the author introduces seven issues that one should consider when applying machine learning models to radiation therapy.

Emission and propagation of Saturn kilometric radiation: Magnetoionic modes, beaming pattern, and polarization state

NASA Astrophysics Data System (ADS)

Lamy, L.; Cecconi, B.; Zarka, P.; Canu, P.; Schippers, P.; Kurth, W. S.; Mutel, R. L.; Gurnett, D. A.; Menietti, D.; Louarn, P.

2011-04-01

The Cassini mission crossed the source region of the Saturn kilometric radiation (SKR) on 17 October 2008. On this occasion, the Radio and Plasma Wave Science (RPWS) experiment detected both local and distant radio sources, while plasma parameters were measured in situ by the magnetometer and the Cassini Plasma Spectrometer. A goniopolarimetric inversion was applied to RPWS three-antenna electric measurements to determine the wave vector k and the complete state of polarization of detected waves. We identify broadband extraordinary (X) mode as well as narrowband ordinary (O) mode SKR at low frequencies. Within the source region, SKR is emitted just above the X mode cutoff frequency in a hot plasma, with a typical electron-to-wave energy conversion efficiency of ˜1% (2% peak). The knowledge of the k vector is then used to derive the locus of SKR sources in the kronian magnetosphere, which shows X and O components emanating from the same regions. We also compute the associated beaming angle at the source θ‧ = (k, -B) either from (1) in situ measurements or a model of the magnetic field vector (for local to distant sources) or (2) polarization measurements (for local sources). Obtained results, similar for both modes, suggest quasi-perpendicular emission for local sources, whereas the beaming pattern of distant sources appears as a hollow cone with a frequency-dependent constant aperture angle: θ‧ = 75° ± 15° below 300 kHz, decreasing at higher frequencies to reach θ‧ (1000 kHz) = 50° ± 25°. Finally, we investigate quantitatively the SKR polarization state, observed to be strongly elliptical at the source, and quasi-purely circular for sources located beyond approximately two kronian radii. We show that conditions of weak mode coupling are achieved along the raypath, under which the magnetoionic theory satisfactorily describes the evolution of the observed polarization. These results are analyzed comparatively with the auroral kilometric radiation at Earth.

RADIATION PRESERVATION OF FRESH STRAWBERRIES AND GRAPES. Report No. 3 (Final), March 5, 1959-March 5, 1961

DOE Office of Scientific and Technical Information (OSTI.GOV)

Romani, R.J.; Maxie, E.C.; Robinson, B.J.

1962-10-31

A study was nmade of the effects of radiation processing on the keeping qualities of pears. Both gamma and beta exposure prolonged the ripening process in the fruit. Data are included on the effects of radiation on respiration of the fruit. Methods are described for preparing enzyme extracts and lyophilized material for biochemical studies. (C.H.)

Experimental Results of Site Calibration and Sensitivity Measurements in OTR for UWB Systems

NASA Astrophysics Data System (ADS)

Viswanadham, Chandana; Rao, P. Mallikrajuna

2017-06-01

System calibration and parameter accuracy measurement of electronic support measures (ESM) systems is a major activity, carried out by electronic warfare (EW) engineers. These activities are very critical and needs good understanding in the field of microwaves, antennas, wave propagation, digital and communication domains. EW systems are broad band, built with state-of-the art electronic hardware, installed on different varieties of military platforms to guard country's security from time to time. EW systems operate in wide frequency ranges, typically in the order of thousands of MHz, hence these are ultra wide band (UWB) systems. Few calibration activities are carried within the system and in the test sites, to meet the accuracies of final specifications. After calibration, parameters are measured for their accuracies either in feed mode by injecting the RF signals into the front end or in radiation mode by transmitting the RF signals on to system antenna. To carry out these activities in radiation mode, a calibrated open test range (OTR) is necessary in the frequency band of interest. Thus site calibration of OTR is necessary to be carried out before taking up system calibration and parameter measurements. This paper presents the experimental results of OTR site calibration and sensitivity measurements of UWB systems in radiation mode.

The NASA/National Space Science Data Center trapped radiation environment model program, 1964 - 1991

NASA Technical Reports Server (NTRS)

Vette, James I.

1991-01-01

The major effort that NASA, initially with the help of the United States Air Force (USAF), carried out for 27 years to synthesize the experimental and theoretical results of space research related to energetic charged particles into a quantitative description of the terrestrial trapped radiation environment in the form of model environments is detailed. The effort is called the Trapped Radiation Environment Modeling Program (TREMP). In chapter 2 the historical background leading to the establishment of this program is given. Also, the purpose of this modeling program as established by the founders of the program is discussed. This is followed in chapter 3 by the philosophy and approach that was applied in this program throughout its lifetime. As will be seen, this philosophy led to the continuation of the program long after it would have expired. The highlights of the accomplishments are presented in chapter 4. A view to future possible efforts in this arena is given in chapter 5, mainly to pass on to future workers the differences that are perceived from these many years of experience. Chapter 6 is an appendix that details the chronology of the development of TREMP. Finally, the references, which document the work accomplished over these years, are presented in chapter 7.

Theoretical study on the low-lying excited states of the phosphorus monoiodide (PI) including the spin-orbit coupling

NASA Astrophysics Data System (ADS)

Zhang, Xiaomei; Liu, Xiaoting; Liang, Guiying; Li, Rui; Xu, Haifeng; Yan, Bing

2016-01-01

The potential energy curves (PECs) of the 22 Λ-S states of the phosphorus monoiodide (PI) molecule have been calculated at the level of MRCI+Q method with correlation-consistent quadruple-ζ quality basis set. The spectroscopic constants of the bound states are determined, which well reproduce the available measurements. The metastable a1Δ state has been reported for the first time, which lies between the X3Σ- and b1Σ+ states and have much deeper well than the ground state. The R-dependent spin-orbit (SO) matrix elements are calculated with the full-electron Breit-Pauli operator. Based on the SO matrix elements, the perturbations that the 23Π state may suffer from are analyzed in detail. The SOC effect makes the original Λ-S states split into 51 Ω states. In the zero-field splitting of the ground state X3Σ-, the spin-spin coupling contribution (2.23 cm-1) is found to be much smaller compared to the spin-orbit coupling contribution (50 cm-1). The avoided crossings between the Ω states lead to much shallower potential wells and the change of dissociation relationships of the states. The Ω-state wavefunctions are analyzed depending on their Λ-S compositions, showing the strong interactions among several quasidegenerate Λ-S states of the same total SO symmetry. The transition properties including electric dipole (E1), magnetic dipole (M1), and electric quadrupole (E2) transition moments (TMs), the Franck-Condon factors, the transition probabilities and the radiative lifetimes are computed for the transitions between Ω components of a1Δ and b1Σ+ states and ground state. The transition probabilities induced by the E1, E2, and M1 transitions are evaluated. The E2 makes little effect on transition probabilities. In contrast, the E1 transition makes the main contribution to the transition probability and the M1 transition also brings the influence that cannot be neglected. Finally, the radiative lifetimes are determined with the transition moments including E1 and M1. The lifetime of transition (2)0+-X10+ is evaluated at the level of millisecond, much smaller than that of the transition (2)0+-X21.

Optical communication with two-photon coherent stages. I - Quantum-state propagation and quantum-noise reduction

NASA Technical Reports Server (NTRS)

Yuen, H. P.; Shapiro, J. H.

1978-01-01

To determine the ultimate performance limitations imposed by quantum effects, it is also essential to consider optimum quantum-state generation. Certain 'generalized' coherent states of the radiation field possess novel quantum noise characteristics that offer the potential for greatly improved optical communications. These states have been called two-photon coherent states because they can be generated, in principle, by stimulated two-photon processes. The use of two-photon coherent state (TCS) radiation in free-space optical communications is considered. A simple theory of quantum state propagation is developed. The theory provides the basis for representing the free-space channel in a quantum-mechanical form convenient for communication analysis. The new theory is applied to TCS radiation.

Single-Photon Nanoantennas

PubMed Central

2017-01-01

Single-photon nanoantennas are broadband strongly scattering nanostructures placed in the near field of a single quantum emitter, with the goal to enhance the coupling between the emitter and far-field radiation channels. Recently, great strides have been made in the use of nanoantennas to realize fluorescence brightness enhancements, and Purcell enhancements, of several orders of magnitude. This perspective reviews the key figures of merit by which single-photon nanoantenna performance is quantified and the recent advances in measuring these metrics unambiguously. Next, this perspective discusses what the state of the art is in terms of fluoresent brightness enhancements, Purcell factors, and directivity control on the level of single photons. Finally, I discuss future challenges for single-photon nanoantennas. PMID:29354664

Direct processes in 54-MeV Li-7 breakup reactions on C-12 and Au-197 targets, and the extraction of astrophysical cross sections

NASA Astrophysics Data System (ADS)

Gazes, S. B.; Mason, J. E.; Roberts, R. B.; Teichmann, S. G.

1992-01-01

Strong direct processes were observed for elastic breakup in 54-MeV Li-7 + C-12, Au-197 reactions. In the case of C-12, the observed Li-7 to alpha + t direct-breakup yield was significantly larger than predicted by a Coulomb-breakup calculation, indicating the importance of the nuclear field. For Au-197, final-state interactions produced a strong distortion in the fragment energy spectra, as well as a modulation of the coincidence efficiency for different detector geometries. Such Coulomb effects are found to severely complicate the extraction of radiative-capture cross sections from direct-breakup data.

Transverse momentum and its compensation in current and target jets in deep inelastic muon-proton scattering

NASA Astrophysics Data System (ADS)

Arneodo, M.; Arvidson, A.; Aubert, J. J.; Beaufays, J.; Becks, K. H.; Bee, C.; Benchouk, C.; Bird, I.; Blum, D.; Böhm, E.; de Bouard, X.; Brasse, F. W.; Braun, H.; Broll, C.; Brown, S.; Brück, H.; Calen, H.; Callebaut, D.; Carr, J.; Chima, J. S.; Clifft, R.; Cobb, J. H.; Coignet, G.; Combley, F.; Coughlan, J.; Court, G. R.; D'Agostini, G.; Dahlgren, S.; Davies, J. K.; Dengler, F.; Derado, I.; Dosselli, U.; Dreyer, T.; Drees, J.; Dumont, J. J.; Düren, M.; Eckardt, V.; Edwards, A.; Edwards, M.; Ernst, T.; Eszes, G.; Favier, J.; Ferrero, M. I.; Figiel, J.; Flauger, W.; Foster, J.; Gabathuler, E.; Gamet, R.; Gayler, J.; Geddes, N.; Giubellino, P.; Gössling, C.; Grafström, P.; Grard, F.; Gustafsson, L.; Haas, J.; Hagberg, E.; Hasert, F. J.; Hayman, P.; Heusse, P.; Hoppe, C.; Jaffré, M.; Jacholkowska, A.; Janata, F.; Jancso, G.; Johnson, A. S.; Kabuss, E. M.; Kellner, G.; Korbel, V.; Krüger, J.; Kullander, S.; Landgraf, U.; Lanske, D.; Loken, J.; Long, K.; Maire, M.; Manz, A.; Mohr, W.; Montanet, F.; Montgomery, H. E.; Mount, R. P.; Nagy, E.; Nassalski, J.; Norton, P. R.; Oakham, F. G.; Osborne, A. M.; Pascaud, C.; Paul, L.; Pawlik, B.; Payre, P.; Peroni, C.; Pessard, H.; Pettingale, J.; Pietrzyk, B.; Pötsch, M.; Preissner, H.; Renton, P.; Ribarics, P.; Rith, K.; Rondio, E.; Schlagböhmer, A.; Schmitz, N.; Schneegans, M.; Schröder, T.; Schultze, K.; Shiers, J.; Sloan, T.; Stier, H. E.; Stockhausen, W.; Studt, M.; Taylor, G. N.; Thénard, J. M.; Thompson, J. C.; de La Torre, A.; Toth, J.; Urban, L.; Wahlen, H.; Wallucks, W.; Whalley, M.; Wheeler, S.; Williams, W. S. C.; Wimpenny, S.; Windmolders, R.; Wolf, G.

1984-12-01

Results are presented on the transverse momentum distributions of charged hadrons in 280 GeV muon-proton deep inelastic interactions. The transverse momenta are defined relative to the accurately measured virtual photon direction and the experiment has almost complete angular acceptance for the final state hadrons. Significantly larger values of the average transverse momentum squared are found for the forward going hadrons than for the target remnants. This result, combined with a study of the rapidity region over which the transverse momentum is compensated, can be explained by a significant contribution from soft gluon radiation, but not by a large value of the primordial transverse momentum of the struck quark.

Final Progress Report for Collaborative Research: Aging of Black Carbon during Atmospheric Transport: Understanding Results from the DOE’s 2010 CARES and 2012 ClearfLo Campaigns

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mazzoleni, Claudio; Subramanian, R.

2016-08-31

Over the course of this project, we have analyzed data and samples from the Carbonaceous Aerosol and Radiative Effects Study (CARES) and the Clear air for London (ClearfLo) campaign, as well as conducted or participated in laboratory experiments designed to better understand black carbon mixing state and climate-relevant properties. The laboratory campaigns took place at the Pacific Northwest National Laboratory and Carnegie Mellon University to study various climate-relevant aerosol properties of different sources of soot mixing with secondary organic aerosol precursors. Results from some of these activities were summarized in the previous progress report. This final report presents the manuscriptsmore » that have been published (many in the period since the last progress report), lists presentations at different conferences based on grant-related activities, and presents some results that are likely to be submitted for publication in the near future.« less

A note from history: Landmarks in history of cancer, Part 6.

PubMed

Hajdu, Steven I; Vadmal, Manjunath

2013-12-01

In the 3 decades from 1940 to 1970, the United States became the nucleus for research, diagnosis, and treatment of cancer. The discovery of anticancer drugs, and the clinical demonstration that chemotherapy and radiation can cure cancer and have the ability to prevent recurrence of cancer, were incontrovertibly the most remarkable groundbreaking events. Consequently, the trend of less surgery and more multimodality therapy began. The introduction of radioautography, mammography, ultrasonography, computed tomography, Papanicolaou smear, and other novel laboratory tests furthered early detection of cancer and refined accurate diagnosis. The unequivocal linking of lung cancer to cigarette smoking made medical history. The delineation of the potential role of oncogenes adduced new thoughts about oncogenesis and cancer prevention, and pathologists finalized the classification and nosology of tumors. Finally, it is worth noting that although more advances were made in the detection, diagnosis, and treatment of cancers than any other period in history, the overall mortality rate of patients with cancer remained high and unchanged. © 2013 American Cancer Society.

Analytical fuel property effects--small combustors

NASA Technical Reports Server (NTRS)

Sutton, R. D.; Troth, D. L.; Miles, G. A.

1984-01-01

The consequences of using broad-property fuels in both conventional and advanced state-of-the-art small gas turbine combustors are assessed. Eight combustor concepts were selected for initial screening, of these, four final combustor concepts were chosen for further detailed analysis. These included the dual orifice injector baseline combustor (a current production 250-C30 engine combustor) two baseline airblast injected modifications, short and piloted prechamber combustors, and an advanced airblast injected, variable geometry air staged combustor. Final predictions employed the use of the STAC-I computer code. This quasi 2-D model includes real fuel properties, effects of injector type on atomization, detailed droplet dynamics, and multistep chemical kinetics. In general, fuel property effects on various combustor concepts can be classified as chemical or physical in nature. Predictions indicate that fuel chemistry has a significant effect on flame radiation, liner wall temperature, and smoke emission. Fuel physical properties that govern atomization quality and evaporation rates are predicted to affect ignition and lean-blowout limits, combustion efficiency, unburned hydrocarbon, and carbon monoxide emissions.

Universality of next-to-leading power threshold effects for colourless final states in hadronic collisions

NASA Astrophysics Data System (ADS)

Del Duca, V.; Laenen, E.; Magnea, L.; Vernazza, L.; White, C. D.

2017-11-01

We consider the production of an arbitrary number of colour-singlet particles near partonic threshold, and show that next-to-leading order cross sections for this class of processes have a simple universal form at next-to-leading power (NLP) in the energy of the emitted gluon radiation. Our analysis relies on a recently derived factorisation formula for NLP threshold effects at amplitude level, and therefore applies both if the leading-order process is tree-level and if it is loop-induced. It holds for differential distributions as well. The results can furthermore be seen as applications of recently derived next-to-soft theorems for gauge theory amplitudes. We use our universal expression to re-derive known results for the production of up to three Higgs bosons at NLO in the large top mass limit, and for the hadro-production of a pair of electroweak gauge bosons. Finally, we present new analytic results for Higgs boson pair production at NLO and NLP, with exact top-mass dependence.

Radiation oncology in Canada.

PubMed

Giuliani, Meredith; Gospodarowicz, Mary

2018-01-01

In this article we provide an overview of the Canadian healthcare system and the cancer care system in Canada as it pertains to the governance, funding and delivery of radiotherapy programmes. We also review the training and practice for radiation oncologists, medical physicists and radiation therapists in Canada. We describe the clinical practice of radiation medicine from patients' referral, assessment, case conferences and the radiotherapy process. Finally, we provide an overview of the practice culture for Radiation Oncology in Canada. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Infrared band absorptance correlations and applications to nongray radiation. [mathematical models of absorption spectra for nongray atmospheres in order to study air pollution

NASA Technical Reports Server (NTRS)

Tiwari, S. N.; Manian, S. V. S.

1976-01-01

Various mathematical models for infrared radiation absorption spectra for atmospheric gases are reviewed, and continuous correlations for the total absorptance of a wide band are presented. Different band absorptance correlations were employed in two physically realistic problems (radiative transfer in gases with internal heat source, and heat transfer in laminar flow of absorbing-emitting gases between parallel plates) to study their influence on final radiative transfer results. This information will be applied to the study of atmospheric pollutants by infrared radiation measurement.

Radiation Protection Research Needs Workshop: Summary Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dewji, Shaheen A.; Davis, Jason; Hertel, Nolan E.

In order to protect humans and the environment when using ionizing radiation for the advancement and benefit of society, accurately quantifying radiation and its potential effects remains the driver for ensuring the safety and secure use of nuclear and radiological applications of technology. In the realm of radiation protection and its various applications with the nuclear fuel cycle, (nuclear) medicine, emergency response, national defense, and space exploration, the scientific and research needs to support state and federal radiation protection needs in the United States in each of these areas are still deficient.

Disposal of Energy by UV-B Sunscreens

NASA Astrophysics Data System (ADS)

Nordlund, Thomas; Krishnan, Rajagopal

2008-03-01

Ideal sunscreens absorb dangerous UV light and dispose of the energy safely. ``Safe disposal'' usually means conversion to heat. However, efficient absorption entails a high radiative rate, which implies high energy-transfer and other rates, unless some process intervenes to ``defuse'' the excited state. We studied the excited-state kinetics of three UV-B (290-320 nm) sunscreens by absorption, steady-state and time-resolved fluorescence. Excited-state rate analysis suggests that some sunscreens have low radiative-rate ``dark'' states, in addition to normal excited states.* We deduce dark states when sunscreens of high extinction coefficient do not show lifetimes and total emission consistent with such high radiative rates. A high radiative rate, accompanied by efficient fluorescence emission and/or transfer, may be unfavorable for a sunscreen. In spite of its dark excited state, padimate O shows significant re-emission of light in the UV-A (320-400 nm) and energy transfer to a natural component of excised skin, probably collagen. * Krishnan, R. and T.M. Nordlund (2007) J. Fluoresc. DOI 10.1007/s10895-007-0264-3.

High-order multipole radiation from quantum Hall states in Dirac materials

NASA Astrophysics Data System (ADS)

Gullans, Michael J.; Taylor, Jacob M.; Imamoǧlu, Ataç; Ghaemi, Pouyan; Hafezi, Mohammad

2017-06-01

We investigate the optical response of strongly disordered quantum Hall states in two-dimensional Dirac materials and find qualitatively different effects in the radiation properties of the bulk versus the edge. We show that the far-field radiation from the edge is characterized by large multipole moments (>50 ) due to the efficient transfer of angular momentum from the electrons into the scattered light. The maximum multipole transition moment is a direct measure of the coherence length of the edge states. Accessing these multipole transitions would provide new tools for optical spectroscopy and control of quantum Hall edge states. On the other hand, the far-field radiation from the bulk appears as random dipole emission with spectral properties that vary with the local disorder potential. We determine the conditions under which this bulk radiation can be used to image the disorder landscape. Such optical measurements can probe submicron-length scales over large areas and provide complementary information to scanning probe techniques. Spatially resolving this bulk radiation would serve as a novel probe of the percolation transition near half filling.

76 FR 25725 - Final Regulatory Guide: Issuance, Availability

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-05

....18, Revision 2, ``Information Relevant to Ensuring that Occupational Radiation Exposures at Medical..., techniques that the staff uses in evaluating specific problems or postulated accidents, and data that the..., ``Information Relevant to Ensuring that Occupational Radiation Exposures at Medical Institutions will be As Low...

Complexity Reduction of Collisional-Radiative Kinetics for Atomic Plasma

DTIC Science & Technology

2013-12-23

through collisional and radiative interactions .4–6 The most accurate treatment for these non- equilibrium plasmas requires a state-to-state approach,7–13...CR system versus time, during con- stant-Te plasma evolution from a low -temperature ASDF and low electron number density; as excitation and...Collisional-radiative model in air for earth re-entry problems,” Phys. Plasmas 13, 043502 (2006). 9C. O. Laux, L. Pierrot, and R. J. Gessman, “State-to

Decay, excitation, and ionization of lithium Rydberg states by blackbody radiation

NASA Astrophysics Data System (ADS)

Ovsiannikov, V. D.; Glukhov, I. L.

2010-09-01

Details of interaction between the blackbody radiation and neutral lithium atoms were studied in the temperature ranges T = 100-2000 K. The rates of thermally induced decays, excitations and ionization were calculated for S-, P- and D-series of Rydberg states in the Fues' model potential approach. The quantitative regularities for the states of the maximal rates of blackbody-radiation-induced processes were determined. Approximation formulas were proposed for analytical representation of the depopulation rates.

Measurement of absolute hadronic branching fractions of D mesons and e+e-→DD¯ cross sections at the ψ(3770)

NASA Astrophysics Data System (ADS)

Dobbs, S.; Metreveli, Z.; Seth, K. K.; Tomaradze, A.; Ecklund, K. M.; Love, W.; Savinov, V.; Lopez, A.; Mehrabyan, S.; Mendez, H.; Ramirez, J.; Huang, G. S.; Miller, D. H.; Pavlunin, V.; Sanghi, B.; Shipsey, I. P. J.; Xin, B.; Adams, G. S.; Anderson, M.; Cummings, J. P.; Danko, I.; Hu, D.; Moziak, B.; Napolitano, J.; He, Q.; Insler, J.; Muramatsu, H.; Park, C. S.; Thorndike, E. H.; Yang, F.; Artuso, M.; Blusk, S.; Khalil, S.; Li, J.; Menaa, N.; Mountain, R.; Nisar, S.; Randrianarivony, K.; Sia, R.; Skwarnicki, T.; Stone, S.; Wang, J. C.; Bonvicini, G.; Cinabro, D.; Dubrovin, M.; Lincoln, A.; Asner, D. M.; Edwards, K. W.; Naik, P.; Briere, R. A.; Ferguson, T.; Tatishvili, G.; Vogel, H.; Watkins, M. E.; Rosner, J. L.; Adam, N. E.; Alexander, J. P.; Berkelman, K.; Cassel, D. G.; Duboscq, J. E.; Ehrlich, R.; Fields, L.; Gibbons, L.; Gray, R.; Gray, S. W.; Hartill, D. L.; Heltsley, B. K.; Hertz, D.; Jones, C. D.; Kandaswamy, J.; Kreinick, D. L.; Kuznetsov, V. E.; Mahlke-Krüger, H.; Mohapatra, D.; Onyisi, P. U. E.; Patterson, J. R.; Peterson, D.; Pivarski, J.; Riley, D.; Ryd, A.; Sadoff, A. J.; Schwarthoff, H.; Shi, X.; Stroiney, S.; Sun, W. M.; Wilksen, T.; Athar, S. B.; Patel, R.; Yelton, J.; Rubin, P.; Cawlfield, C.; Eisenstein, B. I.; Karliner, I.; Kim, D.; Lowrey, N.; Selen, M.; White, E. J.; Wiss, J.; Mitchell, R. E.; Shepherd, M. R.; Besson, D.; Pedlar, T. K.; Cronin-Hennessy, D.; Gao, K. Y.; Hietala, J.; Kubota, Y.; Klein, T.; Lang, B. W.; Poling, R.; Scott, A. W.; Smith, A.; Zweber, P.

2007-12-01

Using 281pb-1 of e+e- collisions recorded at the ψ(3770) resonance with the CLEO-c detector at CESR (Cornell Electron Storage Ring), we determine absolute hadronic branching fractions of charged and neutral D mesons using a double tag technique. Among measurements for three D0 and six D+ modes, we obtain reference branching fractions B(D0→K-π+)=(3.891±0.035±0.059±0.035)% and B(D+→K-π+π+)=(9.14±0.10±0.16±0.07)%, where the first uncertainty is statistical, the second is all systematic errors other than final-state radiation (FSR), and the third is the systematic uncertainty due to FSR. We include FSR in these branching fractions by allowing for additional unobserved photons in the final state. Using an independent determination of the integrated luminosity, we also extract the cross sections σ(e+e-→D0D¯0)=(3.66±0.03±0.06)nb and σ(e+e-→D+D-)=(2.91±0.03±0.05)nb at a center-of-mass energy, Ecm=3774±1MeV.

Measurement of solar radiation at the Earth's surface

NASA Technical Reports Server (NTRS)

Bartman, F. L.

1982-01-01

The characteristics of solar energy arriving at the surface of the Earth are defined and the history of solar measurements in the United States presented. Radiation and meteorological measurements being made at solar energy meteorological research and training sites and calibration procedures used there are outlined. Data illustrating the annual variation in daily solar radiation at Ann Arbor, Michigan and the diurnal variation in radiation at Albuquerque, New Mexico are presented. Direct normal solar radiation received at Albuquerque is contrasted with that received at Maynard, Massachusetts. Average measured global radiation for a period of one year for four locations under clear skies, 50% cloud cover, and 100% cloud cover is given and compared with the solar radiation at the top of the atmosphere. The May distribution of mean daily direct solar radiation and mean daily global solar radiation over the United States is presented. The effects of turbidity on the direct and circumsolar radiation are shown.

Project GALILEO: Farewell to the Major Moons of Jupiter

NASA Astrophysics Data System (ADS)

Theilig, E.

2002-01-01

After a six year odyssey, Galileo has completed its survey of the large moons of Jupiter. In the four years since the end of the primary mission, Galileo provided new insights into the fundamental questions concerning Jupiter and its moons and magnetosphere. Longevity, changing orbital geometry, and multiple flybys afforded the opportunity to distinguish intrinsic versus induced magnetic fields on the Galilean moons, to characterize the dusk side of the magnetosphere, to acquire high resolution observations supporting the possibility of subsurface water within Europa, Ganymede, and Callisto, and to monitor the highly dynamic volcanic activity of Io. In January 2002, a final gravity assist placed the spacecraft on a two-orbit trajectory culminating in a Jupiter impact in September 2003. With the successful completion of the Io encounters, plans are being made for the final encounter of the mission. In November 2002, the spacecraft will fly one Jupiter radius above the planet's cloud-tops, sampling the inner magnetosphere and the gossamer rings. The trajectory will take Galileo close enough to Amalthea, (a small inner moon) to obtain the first gravity data for this body. Because a radiation dose of 73 krads is expected on this encounter, which will bring the total radiation dose to greater than four times the spacecraft design limits, the command sequence has to account for the possibility of subsystem failure and the loss of spacecraft control after this perijove passage. One of the primary objectives this year has been to place the spacecraft on a trajectory to impact Jupiter on orbit 35. Galileo's discovery of water beneath the frozen surface of Europa raised concerns about forward contamination by inadvertently impacting that moon and resulted in an end of mission requirement to dispose of the spacecraft. A risk assessment of the final two Io encounters was performed to manage the project's ability to meet this requirement. Radiation affected the extended mission through damage to electronic parts in the attitude control subsystem, the computer memory and some science instruments and by causing transient bus reset indications. Software patches and changed operating strategies were implemented to work around most of the radiation effects. Recovery efforts to enhance the robustness of the Solid State Imaging camera paid off in the acquisition of images at both Io 32 and Io 33. Data on spacecraft performance in the harsh jovian environment may be useful to designers of future missions to Jupiter and its moons.

Earth Radiation Measurement Science

NASA Technical Reports Server (NTRS)

Smith, G. Louis

2000-01-01

This document is the final report for NASA Grant NAG1-1959, 'Earth Radiation Measurement Science'. The purpose of this grant was to perform research in this area for the needs of the Clouds and Earth Radiant Energy System (CERES) project and for the Earth Radiation Budget Experiment (ERBE), which are bing conducted by the Radiation and Aerosols Branch of the Atmospheric Sciences Division of Langley Research Center. Earth Radiation Measurement Science investigates the processes by which measurements are converted into data products. Under this grant, research was to be conducted for five tasks: (1) Point Response Function Measurements; (2) Temporal Sampling of Outgoing Longwave Radiation; (3) Spatial Averaging of Radiation Budget Data; (4) CERES Data Validation and Applications; and (5) ScaRaB Data Validation and Application.

Implications of z ~ 6 Quasar Proximity Zones for the Epoch of Reionization and Quasar Lifetimes

DOE PAGES

Eilers, Anna-Christina; Davies, Frederick B.; Hennawi, Joseph F.; ...

2017-05-02

In this paper, we study quasar proximity zones in the redshift rangemore » $$5.77\\leqslant z\\leqslant 6.54$$ by homogeneously analyzing 34 medium-resolution spectra, encompassing both archival and newly obtained data, and exploiting recently updated systemic redshift and magnitude measurements. Whereas previous studies found strong evolution of proximity zone sizes with redshift and argued that this provides evidence for a rapidly evolving intergalactic medium (IGM) neutral fraction during reionization, we measure a much shallower trend $$\\propto {(1+z)}^{-1.44}$$. We compare our measured proximity zone sizes to predictions from hydrodynamical simulations post-processed with one-dimensional radiative transfer and find good agreement between observations and theory, irrespective of the ionization state of the ambient IGM. This insensitivity to IGM ionization state has been previously noted, and results from the fact that the definition of proximity zone size as the first drop of the smoothed quasar spectrum below the 10% flux transmission level probes locations where the ionizing radiation from the quasar is an order of magnitude larger than the expected ultraviolet ionizing background that sets the neutral fraction of the IGM. Our analysis also uncovered three objects with exceptionally small proximity zones (two have $${R}_{p}\\lt 1$$ proper Mpc), which constitute outliers from the observed distribution and are challenging to explain with our radiative transfer simulations. Finally, we consider various explanations for their origin, such as strong absorption line systems associated with the quasar or patchy reionization, but find that the most compelling scenario is that these quasars have been shining for ≲10 5 years.« less

Estimation of Biomass Burning Emissions by Fusing Fire Radiative Power Observed from Polar-orbiting and Geostationary Satellites across the Continental United States

NASA Astrophysics Data System (ADS)

Li, F.; Zhang, X.; Kondragunta, S.

2016-12-01

Trace gases and aerosols released from biomass burning significantly disturb the energy balance of the Earth and also degrade regional air quality. However, biomass burning emissions (BBE) have been poorly estimated using the traditional bottom-up approach because of the substantial uncertainties in the burned area and fuel loads. Recently, Fire Radiative Power (FRP) derived from satellite fire observations enables the estimation of BBE at multiple spatial scales in near real time. Nonetheless, it is very challenging to accurately produce reliable FRP diurnal cycles from either polar-orbiting satellites or geostationary satellites for the calculation of the temporally integrated FRP, Fire Radiative Energy (FRE). Here we reconstruct FRP diurnal cycles by fusing FRP observed from polar-orbiting and geostationary satellites and estimate BBE from 2011 to 2015 across the Continental United States. Specifically, FRP from the Geostationary Operational Environmental Satellite (GOES) is preprocessed and calibrated using the collocated and concurred observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) over Landsat TM burn scars. The climatologically diurnal FRP curves are then calculated from the calibrated GOES FRP for the 25 Bailey's ecoregions. By fitting MODIS FRP and the calibrated GOES FRP to the climatological curves, FRP diurnal cycles are further reconstructed for individual days at a 0.25-degree grid. Both FRE estimated from FRP diurnal cycles and ecoregion specified FRE combustion rates are used to estimate hourly BBE. The estimated BBE is finally evaluated using QFED and GFED4.0 inventories and emissions modeled using Landsat TM 30m burn severities and 30m fuel loading from Fuel Characteristic Classification System. The results show that BBE estimates are greatly improved by using the reconstructed FRP diurnal cycles from high temporal (GOES) and high spatial resolution (MODIS) FRP observations.

Hawking radiation in a d-dimensional static spherically symmetric black hole surrounded by quintessence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen Songbai; Wang Bin; Su Rukeng

2008-06-15

We present a solution of Einstein equations with quintessential matter surrounding a d-dimensional black hole, whose asymptotic structures are determined by the state of the quintessential matter. We examine the thermodynamics of this black hole and find that the mass of the black hole depends on the equation of state of the quintessence, while the first law is universal. Investigating the Hawking radiation in this black hole background, we observe that the Hawking radiation dominates on the brane in the low-energy regime. For different asymptotic structures caused by the equation of state of the quintessential matter surrounding the black hole,more » we learn that the influences by the state parameter of the quintessence on Hawking radiation are different.« less

Thermal Considerations of Space Solar Power Concepts with 3.5 GW RF Output

NASA Technical Reports Server (NTRS)

Choi, Michael K.

2000-01-01

This paper presents the thermal challenge of the Space Solar Power (SSP) design concepts with a 3.5 GW radio-frequency (RF) output. High efficiency klystrons are thermally more favored than solid state (butterstick) to convert direct current (DC) electricity to radio-frequency (RF) energy at the transmitters in these concepts. Using klystrons, the heat dissipation is 0.72 GW. Using solid state, the heat dissipation is 2.33 GW. The heat dissipation of the klystrons is 85% at 500C, 10% at 300C, and 5% at 125C. All the heat dissipation of the solid state is at 100C. Using klystrons, the radiator area is 74,500 square m Using solid state, the radiator area is 2,362,200 square m Space constructable heat pipe radiators are assumed in the thermal analysis. Also, to make the SSP concepts feasible, the mass of the heat transport system must be minimized. The heat transport distance from the transmitters to the radiators must be minimized. It can be accomplished by dividing the radiator into a cluster of small radiators, so that the heat transport distances between the klystrons and radiators can be minimized. The area of each small radiator is on the order of 1 square m. Two concepts for accommodating a cluster of small radiators are presented. If the distance between the transmitters and radiators is 1.5 m or less, constant conductance heat pipes (CCHPs) are acceptable for heat transport. If the distance exceeds 1.5 m, loop heat pipes (LHPs) are needed.

IAEA activities related to radiation biology and health effects of radiation.

PubMed

Wondergem, Jan; Rosenblatt, Eduardo

2012-03-01

The IAEA is involved in capacity building with regard to the radiobiological sciences in its member states through its technical cooperation programme. Research projects/programmes are normally carried out within the framework of coordinated research projects (CRPs). Under this programme, two CRPs have been approved which are relevant to nuclear/radiation accidents: (1) stem cell therapeutics to modify radiation-induced damage to normal tissue, and (2) strengthening biological dosimetry in IAEA member states.

MECHANISMS OF PLANT RESISTANCE TO INCREASED SOLAR ULTRAVIOLET-B RADIATION

EPA Science Inventory

Since the major conclusions of the project are being disseminated via the scientific literature, the final report consists of a compilation of 11 articles and manuscripts on the effects of ultraviolet-B radiation (UVB) on soybean growth and yield, stress interactions with UVB, an...

Gamma Decay of Unbound Neutron-Hole States in 133Sn

NASA Astrophysics Data System (ADS)

Vaquero, V.; Jungclaus, A.; Doornenbal, P.; Wimmer, K.; Gargano, A.; Tostevin, J. A.; Chen, S.; Nácher, E.; Sahin, E.; Shiga, Y.; Steppenbeck, D.; Taniuchi, R.; Xu, Z. Y.; Ando, T.; Baba, H.; Garrote, F. L. Bello; Franchoo, S.; Hadynska-Klek, K.; Kusoglu, A.; Liu, J.; Lokotko, T.; Momiyama, S.; Motobayashi, T.; Nagamine, S.; Nakatsuka, N.; Niikura, M.; Orlandi, R.; Saito, T.; Sakurai, H.; Söderström, P. A.; Tveten, G. M.; Vajta, Zs.; Yalcinkaya, M.

2017-05-01

Excited states in the nucleus 133Sn, with one neutron outside the double magic 132Sn core, were populated following one-neutron knockout from a 134Sn beam on a carbon target at relativistic energies at the Radioactive Isotope Beam Factory at RIKEN. Besides the γ rays emitted in the decay of the known neutron single-particle states in 133Sn additional γ strength in the energy range 3.5-5.5 MeV was observed for the first time. Since the neutron-separation energy of 133Sn is low, Sn=2.402 (4 ) MeV , this observation provides direct evidence for the radiative decay of neutron-unbound states in this nucleus. The ability of electromagnetic decay to compete successfully with neutron emission at energies as high as 3 MeV above threshold is attributed to a mismatch between the wave functions of the initial and final states in the latter case. These findings suggest that in the region southeast of 132Sn nuclear structure effects may play a significant role in the neutron versus γ competition in the decay of unbound states. As a consequence, the common neglect of such effects in the evaluation of the neutron-emission probabilities in calculations of global β -decay properties for astrophysical simulations may have to be reconsidered.

Gamma Decay of Unbound Neutron-Hole States in ^{133}Sn.

PubMed

Vaquero, V; Jungclaus, A; Doornenbal, P; Wimmer, K; Gargano, A; Tostevin, J A; Chen, S; Nácher, E; Sahin, E; Shiga, Y; Steppenbeck, D; Taniuchi, R; Xu, Z Y; Ando, T; Baba, H; Garrote, F L Bello; Franchoo, S; Hadynska-Klek, K; Kusoglu, A; Liu, J; Lokotko, T; Momiyama, S; Motobayashi, T; Nagamine, S; Nakatsuka, N; Niikura, M; Orlandi, R; Saito, T; Sakurai, H; Söderström, P A; Tveten, G M; Vajta, Zs; Yalcinkaya, M

2017-05-19

Excited states in the nucleus ^{133}Sn, with one neutron outside the double magic ^{132}Sn core, were populated following one-neutron knockout from a ^{134}Sn beam on a carbon target at relativistic energies at the Radioactive Isotope Beam Factory at RIKEN. Besides the γ rays emitted in the decay of the known neutron single-particle states in ^{133}Sn additional γ strength in the energy range 3.5-5.5 MeV was observed for the first time. Since the neutron-separation energy of ^{133}Sn is low, S_{n}=2.402(4)  MeV, this observation provides direct evidence for the radiative decay of neutron-unbound states in this nucleus. The ability of electromagnetic decay to compete successfully with neutron emission at energies as high as 3 MeV above threshold is attributed to a mismatch between the wave functions of the initial and final states in the latter case. These findings suggest that in the region southeast of ^{132}Sn nuclear structure effects may play a significant role in the neutron versus γ competition in the decay of unbound states. As a consequence, the common neglect of such effects in the evaluation of the neutron-emission probabilities in calculations of global β-decay properties for astrophysical simulations may have to be reconsidered.

Principals Of Radiation Toxicology: Important Aspects.

NASA Astrophysics Data System (ADS)

Popov, Dmitri; Maliev, Slava; Jones, Jeffrey

“All things are poison, and nothing is without poison; only the dose permits something not to be poisonous.” Paracelsus Key Words: Radiation Toxins (RT), Radiation Toxicants (RTc), Radiation Poisons (RP), Radiation Exposure (RE), Radiation Toxicology is the science about radiation poisons. [D.Popov et al. 2012,J.Zhou et al. 2007,] Radiation Toxins is a specific proteins with high enzymatic activity produced by living irradiated mammals. [D.Popov et al. 2012,] Radiation Toxicants is a substances that produce radiomimetics effects, adverse biological effects which specific for radiation. [D.Popov et al. 2012,] Radiation Toxic agent is specific proteins that can produce pathological biological effects specific for physical form of radiation.[D.Popov et al. 1990,2012,V. Maliev 2007] Different Toxic Substances isolated from cells or from blood or lymph circulation. [Kudriashov I. et al. 1970, D.Popov et al. 1990,2012,V. Maliev et al. 2007,] Radiation Toxins may affects many organs or specific organ, tissue, specific group of cells. [Kudriashov I. et al. 1970, D.Popov et al. 1990,2012,V. Maliev et al. 2007] For example: Radiation Toxins could induce collective toxic clinical states to include: systemic inflammatory response syndrome (SIRS),toxic multiple organ injury (TMOI), toxic multiple organ dysfunction syndromes (TMODS),and finally, toxic multiple organ failure (TMOF). [T. Azizova et al. 2005, Konchalovsky et al., 2005, D. Popov et al 2012] However, Radiation Toxins could induce specific injury of organs or tissue and induce Acute Radiation Syndromes such as Acute Radiation Cerebrovascular Syndrome, Acute Radiation Cardiovascular Syndrome, Acute Radiation Hematopoietic Syndrome, Acute Radiation GastroIntestinal Syndrome. [ D.Popov et al. 1990, 2012, V. Maliev et al. 2007] Radiation Toxins correlates with Radiation Exposure and the dose-response relationship is a fundamental and essential concept in classic Toxicology and Radiation Toxicology.[ D.Popov et al. 1990, 2012] Moderate and high doses of radiation induces necrosis of radiosensitive cells with the subsequent formation of radiation toxins and their induced acute inflammatory processes. Radiation necrosis is the most substantial and most severe form of radiation induced injury, and when widespread, has grave therapeutic implications. [D. Popov et al. 1990, 2012,Claudio A. et al. 2002, Robertson J. et al. 2002, ] Relatively small doses of Radiation Toxins induce apoptosis and high doses of Radiation Toxins induce necrosis. [Rastogi P. et al. 2009, D. Popov et al. 1990, 2012,] Threshold of Toxic Effects occurs and can be defined. [D. Popov et al. 2012, ] Radiation Toxins affects Somatic cells and Germ Cells. Radiation Toxins can induce teratogenic processes. Specific Toxicity of Radiation Toxins can affects developing fetus. Material and Methods, Results: http://www.intechopen.com/books/current-topics-in-ionizing-radiation-research/radiation-toxins-molecular-mechanisms-of-toxicity-and-radiomimetic-properties- Conclusion: Radiation is a physical agent - induce activation of some secretory proteins with high enzymatic activity. This proteins called as Radiation Toxins can produce specific for radiation biological and toxic effects after administration to radiation naive mammals. [V. Maliev et al. 2007, D. Popov et al. 1990, 2012] Radiation Toxins are teratogenic and oncogenic. Radiation Toxins effects depend on Administered Dose and Radiation effects depend on Exposure Dose and Absorbed Dose. The levels of Radiation Toxins correlates with Radiation Exposure.

Structure in Radiative Shocks

NASA Astrophysics Data System (ADS)

Drake, R. Paul; Visco, A.; Doss, F.; Reighard, A.; Froula, D.; Glenzer, S.; Knauer, J.

2008-05-01

Radiative shocks are shock waves fast enough that radiation from the shock-heated matter alters the structure of the shock. They are of fundamental interest to high-energy-density physics and also have applications throughout astrophysics. This poster will review the dimensionless parameters that determine structure in these shocks and will discuss recent experiments to measure such structure for strongly radiative shocks that are optically thin upstream and optically thick downstream. The shock transition itself heats mainly the ions. Immediately downstream of the shock, the ions heat the electrons and the electrons radiate, producing an optically thin cooling layer, followed by the downstream layer of warm, shocked material. The axial structure of these systems is of interest, because the transition from precursor through the cooling layer to the final state is complex and difficult to calculate. Their lateral structure is also of interest, as they seem likely to be subject to some variation on the Vishniac instability of thin layers. In our experiments to produce such shocks, laser ablation launches a Be plasma into a tube of Xe or Ar gas, at a velocity above 100 km/s. This drives a shock down the tube. Radiography provides fundamental information about the structure and evolution of the shocked material in Xe. Thomson scattering and pyrometry have provided data in Ar. We will summarize the available evidence regarding the properties of these shocks, and will discuss their connections to astrophysical cases. This research was sponsored by the National Nuclear Security Administration under the Stewardship Science Academic Alliances program through DOE Research Grants DE-FG52-07NA28058, DE-FG52-04NA00064, and other grants and contracts.

Transition moments, radiative transition probabilities, and radiative lifetimes for the band systems A 2Π-X 2Σ+, B 2Σ+-X 2Σ+, and A 2Π-A´ 2Δ of scandium monosulfide, ScS

NASA Astrophysics Data System (ADS)

Romeu, João Gabriel Farias; Belinassi, Antonio Ricardo; Ornellas, Fernando R.

2018-05-01

A manifold of electronic states of ScS was investigated with special emphasis on the low-lying states X 2Σ+, A´ 2Δ, A 2Π, and B 2Σ+. For all states, potential energy curves were constructed covering internuclear distances from the equilibrium region through the dissociation limit. For the above states, besides providing the most accurate set of theoretical spectroscopic parameters to date, we have also computed dipole moment functions, transitions dipole moment functions, the associated radiative transition probabilities, and radiative lifetimes. For the states known experimentally, X 2Σ+, A 2Π, and B 2Σ+, our results significantly expand our present knowledge of the energetic profile of these states thus providing a new perspective for understanding the limited spectral data for this species known so far. For the new state, A´ 2Δ, yet unobserved experimentally, our results are sufficiently reliable and accurate to guide spectroscopists on further studies of this species.

Radiative corrections to elastic proton-electron scattering measured in coincidence

NASA Astrophysics Data System (ADS)

Gakh, G. I.; Konchatnij, M. I.; Merenkov, N. P.; Tomasi-Gustafsson, E.

2017-05-01

The differential cross section for elastic scattering of protons on electrons at rest is calculated, taking into account the QED radiative corrections to the leptonic part of interaction. These model-independent radiative corrections arise due to emission of the virtual and real soft and hard photons as well as to vacuum polarization. We analyze an experimental setup when both the final particles are recorded in coincidence and their energies are determined within some uncertainties. The kinematics, the cross section, and the radiative corrections are calculated and numerical results are presented.

Assessment of nonequilibrium radiation computation methods for hypersonic flows

NASA Technical Reports Server (NTRS)

Sharma, Surendra

1993-01-01

The present understanding of shock-layer radiation in the low density regime, as appropriate to hypersonic vehicles, is surveyed. Based on the relative importance of electron excitation and radiation transport, the hypersonic flows are divided into three groups: weakly ionized, moderately ionized, and highly ionized flows. In the light of this division, the existing laboratory and flight data are scrutinized. Finally, an assessment of the nonequilibrium radiation computation methods for the three regimes in hypersonic flows is presented. The assessment is conducted by comparing experimental data against the values predicted by the physical model.

Radiation Hardened Telerobotic Dismantling System Development Final Report CRADA No. TC-1340-96

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, C.; Lightman, A.

This project was a collaborative effort between the University of California, LLNL and RedZone Robotics, Inc. for the development of radiation-hardened telerobotic dismantling systems for use in applications such as nuclear facility remediation, nuclear accident response, and Chemobyltype remediation. The project supported the design, development, fabrication and testing of a Ukrainian robotic systems. The project was completed on time and within budget. All deliverables were completed. The final project deliverables were consistent with the plans developed in the original project with the exception that the fabricated systems remained in Ukraine.

Single Event Effects mitigation with TMRG tool

NASA Astrophysics Data System (ADS)

Kulis, S.

2017-01-01

Single Event Effects (SEE) are a major concern for integrated circuits exposed to radiation. There have been several techniques proposed to protect circuits against radiation-induced upsets. Among the others, the Triple Modular Redundancy (TMR) technique is one of the most popular. The purpose of the Triple Modular Redundancy Generator (TMRG) tool is to automatize the process of triplicating digital circuits freeing the designer from introducing the TMR code manually at the implementation stage. It helps to ensure that triplicated logic is maintained through the design process. Finally, the tool streamlines the process of introducing SEE in gate level simulations for final verification.

Non-strictly black body spectrum from the tunnelling mechanism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Corda, Christian, E-mail: cordac.galilei@gmail.com

2013-10-15

The tunnelling mechanism is widely used to explain Hawking radiation. However, in many cases the analysis used to obtain the Hawking temperature only involves comparing the emission probability for an outgoing particle with the Boltzmann factor. Banerjee and Majhi improved this approach by explicitly finding a black body spectrum associated with black holes. Their result, obtained using a reformulation of the tunnelling mechanism, is in contrast to that of Parikh and Wilczek, who found an emission probability that is compatible with a non-strictly thermal spectrum. Using the recently identified effective state for a black hole, we solve this contradiction viamore » a slight modification of the analysis by Banerjee and Majhi. The final result is a non-strictly black body spectrum from the tunnelling mechanism. We also show that for an effective temperature, we can express the corresponding effective metric using Hawking’s periodicity arguments. Potential important implications for the black hole information puzzle are discussed. -- Highlights: •We review an important result by Banerjee and Majhi on the tunnelling mechanism in the framework of Hawking radiation. •This result is in contrast to another result reported by Parikh and Wilczek. •We introduce the effective state of a black hole. •We explain the contrast via a slight modification of the analysis by Banerjee and Majhi. •We discuss potential important implications for the black hole information puzzle.« less

Time-course study of different innate immune mediators produced by UV-irradiated skin: comparative effects of short and daily versus a single harmful UV exposure.

PubMed

Cela, Eliana M; Friedrich, Adrian; Paz, Mariela L; Vanzulli, Silvia I; Leoni, Juliana; González Maglio, Daniel H

2015-05-01

The modulatory effects of solar UV radiation on the immune system have been widely studied. As the skin is the main target of UV radiation, our purpose was to compare the impact on skin innate immunity of two contrasting ways to be exposed to sunlight. Hairless mice were UV irradiated with a single high UV dose simulating a harmful exposure, or with repetitive low UV doses simulating short occasional daily exposures. Skin samples were taken at different times after UV irradiation to evaluate skin histology, inflammatory cell recruitment, epidermal T-cell population and the mitochondrial function of epidermal cells. The transcriptional profiles of pro-inflammatory cytokines, chemokines, antimicrobial peptides and Toll-like receptors were evaluated by RT-PCR and ELISA in tissue homogenates. Finally, a lymphangiography was performed to assess modification in the lymphatic vessel system. A single high UV dose produces a deep inflammatory state characterized by the production of pro-inflammatory cytokines and chemokines that, in turn, induces the recruitment of neutrophils and macrophages into the irradiated area. On the other hand, repetitive low UV doses drive the skin to a photo-induced alert state in which there is no sign of inflammation, but the epithelium undergoes changes in thickness, the lymphatic circulation increases, and the transcription of antimicrobial peptides is induced. © 2014 John Wiley & Sons Ltd.

Development of Spectral and Atomic Models for Diagnosing Energetic Particle Characteristics in Fast Ignition Experiments

DOE Office of Scientific and Technical Information (OSTI.GOV)

MacFarlane, Joseph J.; Golovkin, I. E.; Woodruff, P. R.

2009-08-07

This Final Report summarizes work performed under DOE STTR Phase II Grant No. DE-FG02-05ER86258 during the project period from August 2006 to August 2009. The project, “Development of Spectral and Atomic Models for Diagnosing Energetic Particle Characteristics in Fast Ignition Experiments,” was led by Prism Computational Sciences (Madison, WI), and involved collaboration with subcontractors University of Nevada-Reno and Voss Scientific (Albuquerque, NM). In this project, we have: Developed and implemented a multi-dimensional, multi-frequency radiation transport model in the LSP hybrid fluid-PIC (particle-in-cell) code [1,2]. Updated the LSP code to support the use of accurate equation-of-state (EOS) tables generated by Prism’smore » PROPACEOS [3] code to compute more accurate temperatures in high energy density physics (HEDP) plasmas. Updated LSP to support the use of Prism’s multi-frequency opacity tables. Generated equation of state and opacity data for LSP simulations for several materials being used in plasma jet experimental studies. Developed and implemented parallel processing techniques for the radiation physics algorithms in LSP. Benchmarked the new radiation transport and radiation physics algorithms in LSP and compared simulation results with analytic solutions and results from numerical radiation-hydrodynamics calculations. Performed simulations using Prism radiation physics codes to address issues related to radiative cooling and ionization dynamics in plasma jet experiments. Performed simulations to study the effects of radiation transport and radiation losses due to electrode contaminants in plasma jet experiments. Updated the LSP code to generate output using NetCDF to provide a better, more flexible interface to SPECT3D [4] in order to post-process LSP output. Updated the SPECT3D code to better support the post-processing of large-scale 2-D and 3-D datasets generated by simulation codes such as LSP. Updated atomic physics modeling to provide for more comprehensive and accurate atomic databases that feed into the radiation physics modeling (spectral simulations and opacity tables). Developed polarization spectroscopy modeling techniques suitable for diagnosing energetic particle characteristics in HEDP experiments. A description of these items is provided in this report. The above efforts lay the groundwork for utilizing the LSP and SPECT3D codes in providing simulation support for DOE-sponsored HEDP experiments, such as plasma jet and fast ignition physics experiments. We believe that taken together, the LSP and SPECT3D codes have unique capabilities for advancing our understanding of the physics of these HEDP plasmas. Based on conversations early in this project with our DOE program manager, Dr. Francis Thio, our efforts emphasized developing radiation physics and atomic modeling capabilities that can be utilized in the LSP PIC code, and performing radiation physics studies for plasma jets. A relatively minor component focused on the development of methods to diagnose energetic particle characteristics in short-pulse laser experiments related to fast ignition physics. The period of performance for the grant was extended by one year to August 2009 with a one-year no-cost extension, at the request of subcontractor University of Nevada-Reno.« less

Internal and external radiative widths in the combined R -matrix and potential-model formalism

NASA Astrophysics Data System (ADS)

Mukhamedzhanov, A. M.; Shubhchintak, Bertulani, C. A.; Hao, T. V. Nhan

2017-02-01

By using the R -matrix approach we calculate the radiative width for a resonance decaying to a bound state through electric-dipole E 1 transitions. The total radiative width is determined by the interference of the nuclear internal and external radiative width amplitudes. For a given channel radius the external radiative width amplitude is model independent and is determined by the asymptotic normalization coefficient (ANC) of the bound state to which the resonance decays. It also depends on the partial resonance width. To calculate the internal radiative width amplitude we show that a single-particle-potential model is appropriate. We compare our results with a few experimental data.

Synthesis of calculational methods for design and analysis of radiation shields for nuclear rocket systems

NASA Technical Reports Server (NTRS)

Capo, M. A.; Disney, R. K.; Jordan, T. A.; Soltesz, R. G.; Woodsum, H. C.

1969-01-01

Eight computer programs make up a nine volume synthesis containing two design methods for nuclear rocket radiation shields. The first design method is appropriate for parametric and preliminary studies, while the second accomplishes the verification of a final nuclear rocket reactor design.

SOLAR OPACITY CALCULATIONS USING THE SUPER-TRANSITION-ARRAY METHOD

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krief, M.; Feigel, A.; Gazit, D., E-mail: menahem.krief@mail.huji.ac.il

A new opacity model has been developed based on the Super-Transition-Array (STA) method for the calculation of monochromatic opacities of plasmas in local thermodynamic equilibrium. The atomic code, named STAR (STA-Revised), is described and used to calculate spectral opacities for a solar model implementing the recent AGSS09 composition. Calculations are carried out throughout the solar radiative zone. The relative contributions of different chemical elements and atomic processes to the total Rosseland mean opacity are analyzed in detail. Monochromatic opacities and charge-state distributions are compared with the widely used Opacity Project (OP) code, for several elements near the radiation–convection interface. STARmore » Rosseland opacities for the solar mixture show a very good agreement with OP and the OPAL opacity code throughout the radiation zone. Finally, an explicit STA calculation was performed of the full AGSS09 photospheric mixture, including all heavy metals. It was shown that, due to their extremely low abundance, and despite being very good photon absorbers, the heavy elements do not affect the Rosseland opacity.« less

CdTe Timepix detectors for single-photon spectroscopy and linear polarimetry of high-flux hard x-ray radiation.

PubMed

Hahn, C; Weber, G; Märtin, R; Höfer, S; Kämpfer, T; Stöhlker, Th

2016-04-01

Single-photon spectroscopy of pulsed, high-intensity sources of hard X-rays - such as laser-generated plasmas - is often hampered by the pileup of several photons absorbed by the unsegmented, large-volume sensors routinely used for the detection of high-energy radiation. Detectors based on the Timepix chip, with a segmentation pitch of 55 μm and the possibility to be equipped with high-Z sensor chips, constitute an attractive alternative to commonly used passive solutions such as image plates. In this report, we present energy calibration and characterization measurements of such devices. The achievable energy resolution is comparable to that of scintillators for γ spectroscopy. Moreover, we also introduce a simple two-detector Compton polarimeter setup with a polarimeter quality of (98 ± 1)%. Finally, a proof-of-principle polarimetry experiment is discussed, where we studied the linear polarization of bremsstrahlung emitted by a laser-driven plasma and found an indication of the X-ray polarization direction depending on the polarization state of the incident laser pulse.

CT14 intrinsic charm parton distribution functions from CTEQ-TEA global analysis

NASA Astrophysics Data System (ADS)

Hou, Tie-Jiun; Dulat, Sayipjamal; Gao, Jun; Guzzi, Marco; Huston, Joey; Nadolsky, Pavel; Schmidt, Carl; Winter, Jan; Xie, Keping; Yuan, C.-P.

2018-02-01

We investigate the possibility of a (sizable) nonperturbative contribution to the charm parton distribution function (PDF) in a nucleon, theoretical issues arising in its interpretation, and its potential impact on LHC scattering processes. The "fitted charm" PDF obtained in various QCD analyses contains a process-dependent component that is partly traced to power-suppressed radiative contributions in DIS and is generally different at the LHC. We discuss separation of the universal component of the nonperturbative charm from the rest of the radiative contributions and estimate its magnitude in the CT14 global QCD analysis at the next-to-next-to leading order in the QCD coupling strength, including the latest experimental data from HERA and the Large Hadron Collider. Models for the nonperturbative charm PDF are examined as a function of the charm quark mass and other parameters. The prospects for testing these models in the associated production of a Z boson and a charm jet at the LHC are studied under realistic assumptions, including effects of the final-state parton showering.

Near-field acoustic radiation by high-speed turbulence: amplitude, structure, gas-stiffness, and dilatational dissipation

NASA Astrophysics Data System (ADS)

Buchta, David; Freund, Jonathan

2017-11-01

High-speed (supersonic) turbulent shear flows are well-known to radiate pressure-wave patterns that have higher positive peaks than negative valleys, which yields a notable skewness, usually with Sk > 0.4 . Direct numerical simulations (DNS) of planar turbulent mixing layers at different Mach numbers (M) are used to examine this. The baseline simulations, of an air-like gas at speeds up to M = 3.5 , reproduced the observed behavior of jets. Simulations initialized with corresponding instability modes show that Sk increases linearly with the velocity amplitude (Mt =√{ui' ui'} /co), reflecting the M dependence of the DNS, which can be related to simpler gas dynamic flows. Simulations with a stiffened-gas equation of state (often used to model liquids) show essentially the same Mach-number dependence, despite the nominally greater resistance to compressibility. Turbulence simulations with an artificial energy reallocation mechanism, imposed to alter its structure, show little change in Sk. Finally, we also consider significantly increased bulk viscosity to suppress dilatation. In this case, Sk diminishes along with the sound-field intensity, though the turbulence stresses themselves are nearly unchanged.

SOLVE: a small spacecraft for near lunar environment exploration

NASA Astrophysics Data System (ADS)

Ritter, B.; Karatekin, Ö.; Gerbal, N.; Van Hove, B.; Carrasco, J.; Ranvier, S.; De Keyser, J.

2017-09-01

SOLVE (Small spacecraft fOr near Lunar enViroment Exploration) is a novel mission proposal to employ a 12U CubeSat which will be deployed by a lunar orbiter providing transportation and data relay services. SOLVE will characterize the Lunar environment by studying the complex set of interactions between radiation, illumination, plasma, magnetic field and dust in dependence of altitude. It will decrease its orbit gradually from 500 km altitude in a controlled way until it finally reaches the surface with an attempt to land softly. Besides the above-mentioned geophysical variables, the radiation environment relevant to humans will be measured along the trajectory by detecting highly penetrating ionizing particles (GCRs and SEPs). SOLVE will provide a unique opportunity for demonstration of new and innovative technologies. It will have propulsion systems enabling high Delta-V maneuvers and state-of-art attitude determination and Control System (ADCS) of relevance to future CubeSat missions. Demonstration of small landers for the Moon would open new science opportunities and exploration possibilities that may lead to future geophysical network stations on the Moon as well as other solar system bodies.

Revisit to the RXTE and ASCA Data for GRO J1655-40: Effects of Radiative Transfer in Corona and Color Hardening in the Disk

NASA Technical Reports Server (NTRS)

Zhang, S. Nan; Zhang, Xiaoling; Wu, Xuebing; Yao, Yangsen; Sun, Xuejun; Xu, Haiguang; Cui, Wei; Chen, Wan; Harmon, B. A.; Robinson, C. R.

1999-01-01

The results of spectral modeling of the data for a series of RXTE observations and four ASCA observations of GRO J1655-40 are presented. The thermal Comptonization model is used instead of the power-law model for the hard component of the two-component continuum spectra. The previously reported dramatic variations of the apparent inner disk radius of GRO J1655-40 during its outburst may be due to the inverse Compton scattering in the hot corona. A procedure is developed for making the radiative transfer correction to the fitting parameters from RXTE data and a more stable inner disk radius is obtained. A practical process of determining the color correction (hardening) factor from observational data is proposed and applied to the four ASCA observations of GRO J1655-40. We found that the color correction factor may vary significantly between different observations and the finally corrected physical inner disk radius remains reasonably stable over a large range of luminosity and spectral states.

Solar Resource Measurements in 1400 JR Lynch Street, Jackson, Mississippi: Cooperative Research and Development Final Report, CRADA Number CRD-07-254

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stoffel, Tom

Site-specific, long-term, continuous, and high-resolution measurements of solar irradiance are important for developing renewable resource data. These data are used for several research and development activities consistent with the NREL mission: Equipment will be used by Jackson State University for solar radiation data monitoring. This is a continuing effort of the Historically Black Colleges and Universities Solar Measurement Network; Provide high quality ground-truth data for satellite remote sensing validation; Support development of radiative transfer models for estimating solar irradiance from available meteorological observations; Provide solar resource information needed for technology deployment and operations. Data acquired under this agreement will bemore » available to the public through NREL's Measurement & Instrumentation Data Center (MIDC) (www.nrel.gov/midc) or the Renewable Resource Data Center (RReDC ) (http://rredc.nrel.gov). The MIDC offers a variety of standard data display, access, and analysis tools designed to address the needs of a wide user audience (e.g., industry, academia, and government interests.« less

CdTe Timepix detectors for single-photon spectroscopy and linear polarimetry of high-flux hard x-ray radiation

NASA Astrophysics Data System (ADS)

Hahn, C.; Weber, G.; Märtin, R.; Höfer, S.; Kämpfer, T.; Stöhlker, Th.

2016-04-01

Single-photon spectroscopy of pulsed, high-intensity sources of hard X-rays — such as laser-generated plasmas — is often hampered by the pileup of several photons absorbed by the unsegmented, large-volume sensors routinely used for the detection of high-energy radiation. Detectors based on the Timepix chip, with a segmentation pitch of 55 μm and the possibility to be equipped with high-Z sensor chips, constitute an attractive alternative to commonly used passive solutions such as image plates. In this report, we present energy calibration and characterization measurements of such devices. The achievable energy resolution is comparable to that of scintillators for γ spectroscopy. Moreover, we also introduce a simple two-detector Compton polarimeter setup with a polarimeter quality of (98 ± 1)%. Finally, a proof-of-principle polarimetry experiment is discussed, where we studied the linear polarization of bremsstrahlung emitted by a laser-driven plasma and found an indication of the X-ray polarization direction depending on the polarization state of the incident laser pulse.

CdTe Timepix detectors for single-photon spectroscopy and linear polarimetry of high-flux hard x-ray radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hahn, C., E-mail: christoph.hahn@uni-jena.de; Höfer, S.; Kämpfer, T.

Single-photon spectroscopy of pulsed, high-intensity sources of hard X-rays — such as laser-generated plasmas — is often hampered by the pileup of several photons absorbed by the unsegmented, large-volume sensors routinely used for the detection of high-energy radiation. Detectors based on the Timepix chip, with a segmentation pitch of 55 μm and the possibility to be equipped with high-Z sensor chips, constitute an attractive alternative to commonly used passive solutions such as image plates. In this report, we present energy calibration and characterization measurements of such devices. The achievable energy resolution is comparable to that of scintillators for γ spectroscopy.more » Moreover, we also introduce a simple two-detector Compton polarimeter setup with a polarimeter quality of (98 ± 1)%. Finally, a proof-of-principle polarimetry experiment is discussed, where we studied the linear polarization of bremsstrahlung emitted by a laser-driven plasma and found an indication of the X-ray polarization direction depending on the polarization state of the incident laser pulse.« less

In Situ Biodosimetric Experiment for Space Applications

NASA Astrophysics Data System (ADS)

Goldschmidt, Gergely; Kovaliczky, Éva; Szabó, József; Rontó, Györgyi; Bérces, Attila

2012-06-01

This paper presents the principles and application of DNA based biological UV dosimeters, as developed by Research Group for Biophysics (RGB). These dosimeters are used for assessing the biological hazard of living systems on the Earth's surface and in different waters (rivers, lakes, seas, etc.). The UV dosimetry system has also been used in the space. In dosimeters a bacterial virus, bacteriophage T7 and polycrystalline uracil thin layers have been used as biological detectors. On the Earth's surface the UV radiation induces dimer formation in phage T7 and in the uracil detector, which was evaluated by loss of viability of the phage particles and by the decrease of the characteristic optical density (OD) of uracil thin layers. Recently the development of human space activities has also increased the need to measure the biological effect of extraterrestrial solar radiation, too. The evaluation of the space samples occurred on ground, thus only the starting and the final state were taken into account. A new improved, automated method is presented below which makes data collection more efficient and also makes the dynamics of the process observable.

Pulsational Pair-instability Supernovae

NASA Astrophysics Data System (ADS)

Woosley, S. E.

2017-02-01

The final evolution of stars in the mass range 70-140 {\\text{}}{M}⊙ is explored. Depending upon their mass loss history and rotation rates, these stars will end their lives as pulsational pair-instability supernovae (PPISN) producing a great variety of observational transients with total durations ranging from weeks to millennia and luminosities from 1041 to over 1044 erg s-1. No nonrotating model radiates more than 5× {10}50 erg of light or has a kinetic energy exceeding 5× {10}51 erg, but greater energies are possible, in principle, in magnetar-powered explosions, which are explored. Many events resemble SNe Ibn, SNe Icn, and SNe IIn, and some potential observational counterparts are mentioned. Some PPISN can exist in a dormant state for extended periods, producing explosions millennia after their first violent pulse. These dormant supernovae contain bright Wolf-Rayet stars, possibly embedded in bright X-ray and radio sources. The relevance of PPISN to supernova impostors like Eta Carinae, to superluminous supernovae, and to sources of gravitational radiation is discussed. No black holes between 52 and 133 {\\text{}}{M}⊙ are expected from stellar evolution in close binaries.

The ubiquity of alpine plant radiations: from the Andes to the Hengduan Mountains.

PubMed

Hughes, Colin E; Atchison, Guy W

2015-07-01

Alpine plant radiations are compared across the world's major mountain ranges and shown to be overwhelmingly young and fast, largely confined to the Pliocene and Pleistocene, and some of them apparently in the early explosive phase of radiation. Accelerated diversification triggered by island-like ecological opportunities following the final phases of mountain uplift, and in many cases enabled by the key adaptation of perennial habit, provides a general model for alpine plant radiations. Accelerated growth form evolution facilitated by perenniality provides compelling evidence of ecological release and suggests striking parallels between island-like alpine, and especially tropicalpine radiations, and island radiations more generally. These parallels suggest that the world's mountains offer an excellent comparative system for explaining evolutionary radiation. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

Inclusive χbJ(nP) decays to D0X

NASA Astrophysics Data System (ADS)

Briere, R. A.; Ferguson, T.; Tatishvili, G.; Vogel, H.; Watkins, M. E.; Rosner, J. L.; Alexander, J. P.; Cassel, D. G.; Duboscq, J. E.; Ehrlich, R.; Fields, L.; Galik, R. S.; Gibbons, L.; Gray, R.; Gray, S. W.; Hartill, D. L.; Heltsley, B. K.; Hertz, D.; Kandaswamy, J.; Kreinick, D. L.; Kuznetsov, V. E.; Mahlke-Krüger, H.; Mohapatra, D.; Onyisi, P. U. E.; Patterson, J. R.; Peterson, D.; Riley, D.; Ryd, A.; Sadoff, A. J.; Shi, X.; Stroiney, S.; Sun, W. M.; Wilksen, T.; Athar, S. B.; Patel, R.; Yelton, J.; Rubin, P.; Eisenstein, B. I.; Karliner, I.; Mehrabyan, S.; Lowrey, N.; Selen, M.; White, E. J.; Wiss, J.; Mitchell, R. E.; Shepherd, M. R.; Besson, D.; Pedlar, T. K.; Cronin-Hennessy, D.; Gao, K. Y.; Hietala, J.; Kubota, Y.; Klein, T.; Lang, B. W.; Poling, R.; Scott, A. W.; Zweber, P.; Dobbs, S.; Metreveli, Z.; Seth, K. K.; Tomaradze, A.; Libby, J.; Powell, A.; Wilkinson, G.; Ecklund, K. M.; Love, W.; Savinov, V.; Lopez, A.; Mendez, H.; Ramirez, J.; Ge, J. Y.; Miller, D. H.; Shipsey, I. P. J.; Xin, B.; Adams, G. S.; Anderson, M.; Cummings, J. P.; Danko, I.; Hu, D.; Moziak, B.; Napolitano, J.; He, Q.; Insler, J.; Muramatsu, H.; Park, C. S.; Thorndike, E. H.; Yang, F.; Artuso, M.; Blusk, S.; Khalil, S.; Li, J.; Mountain, R.; Nisar, S.; Randrianarivony, K.; Sultana, N.; Skwarnicki, T.; Stone, S.; Wang, J. C.; Zhang, L. M.; Bonvicini, G.; Cinabro, D.; Dubrovin, M.; Lincoln, A.; Naik, P.; Rademacker, J.; Asner, D. M.; Edwards, K. W.; Reed, J.

2008-11-01

Using Υ(2S) and Υ(3S) data collected with the CLEO III detector we have searched for decays of χbJ to final states with open charm. We fully reconstruct D0 mesons with pD0>2.5GeV/c in three decay modes (K-π+, K-π+π0, and K-π-π+π+) in coincidence with radiative transition photons that tag the production of one of the χbJ(nP) states. Significant signals are obtained for the two J=1 states. Recent nonrelativistic QCD (NRQCD) calculations of χbJ(nP)→c cmacr X depend on one nonperturbative parameter per χbJ triplet. The extrapolation from the observed D0X rate over a limited momentum range to a full c cmacr X rate also depends on these same parameters. Using our data to fit for these parameters, we extract results which agree well with NRQCD predictions, confirming the expectation that charm production is largest for the J=1 states. In particular, for J=1, our results are consistent with c cmacr g accounting for about one-quarter of all hadronic decays.

Commercial implementation of food irradiation

NASA Astrophysics Data System (ADS)

Welt, M. A.

In July 1981, the first specifically designed multi-purpose irradiation facility for food irradiation was put into service by the Radiation Technology, Inc. subsidiary Process Technology, Inc. in West Memphis, Arkansas. The operational experience gained, resulted in an enhanced design which was put into commercial service in Haw River, North Carolina, by another subsidiary, Process Technology (N.C.), Inc. in October 1983. These facilities have enabled the food industry to assess the commercial viability of food irradiation. Further impetus towards commercialization of food irradiation was gained in March 1981 with the filing in the Federal Register, by the FDA, of an Advanced Proposed Notice of Rulemaking for Food Irradiation. Two years later in July 1983, the FDA approved the first food additive regulation involving food irradiation in nineteen years, when they approved the Radiation Technology, Inc. petition calling for the sanitization of spices, onion powder and garlic powder at a maximum dosage of 10 kGy. Since obtaining the spice irradiation approval, the FDA has accepted four additional petitions for filing in the Federal Register. One of the petitions which extended spice irradiation to include insect disinfestation has issued into a regulation while the remaining petitions covering the sanitization of herbs, spice blends, vegetable seasonings and dry powdery enzymes as well as the petition to irradiate hog carcasses and pork products for trichinae control at 1 kGy, are expected to issue either before the end of 1984 or early in 1985. More recently, food irradiation advocates in the United States received another vote of confidence by the announcement that a joint venture food irradiation facility to be constructed in Hawaii by Radiation Technology, is backed by a contractual committment for the processing of 40 million pounds of produce per year. Another step was taken when the Port of Salem, New Jersey announced that the Radiation Technology Model RT-4104-4048(TM) irradiation facility was chosen to interface with the only East Coast grain elevator in the United States. These factors, along with concern over the ban of EDB as a post harvest fumigant, coupled with the expected FDA action to approve the use of irradiation for the insect disinfestation of fruit and vegetables, should finally permit the commercial implementation of food irradiation to take hold in the United States.

Radiation Brain Drain? The Impact of Demographic Change on U.S. Radiation Protection.

PubMed

Hricak, Hedvig; Dauer, Lawrence T

2017-02-01

The use of radiation has a substantial beneficial impact, particularly in the areas of medicine, energy production, basic science research, and industrial applications. Radiation protection knowledge and experience are required for acquiring and implementing scientific knowledge to protect workers, members of the public, and the environment from potential harmful effects of ionizing radiation while facilitating the beneficial use and development of radiation-based technologies. However, demographic changes are negatively impacting U.S. radiation protection and response capabilities. The number of radiation professionals continues to decrease even as the demand for such professionals is growing. These concerns are most pronounced in the medical, energy, research, and security arenas. Though the United States has been the world leader in radiation protection and radiation sciences for many years, the country has no strategic plan to ensure the maintenance of expertise in radiobiology, radiation physics, and radiation protection. Solving this problem will require a significant increase in federal and state funding as well as formal partnerships and initiatives among academia, professional societies, government, and the private sector.

Radiative processes of uniformly accelerated entangled atoms

NASA Astrophysics Data System (ADS)

Menezes, G.; Svaiter, N. F.

2016-05-01

We study radiative processes of uniformly accelerated entangled atoms, interacting with an electromagnetic field prepared in the Minkowski vacuum state. We discuss the structure of the rate of variation of the atomic energy for two atoms traveling in different hyperbolic world lines. We identify the contributions of vacuum fluctuations and radiation reaction to the generation of entanglement as well as to the decay of entangled states. Our results resemble the situation in which two inertial atoms are coupled individually to two spatially separated cavities at different temperatures. In addition, for equal accelerations we obtain that one of the maximally entangled antisymmetric Bell state is a decoherence-free state.

Fundamentals of Radiation Dosimetry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bos, Adrie J. J.

The basic concepts of radiation dosimetry are reviewed on basis of ICRU reports and text books. The radiation field is described with, among others, the particle fluence. Cross sections for indirectly ionizing radiation are defined and indicated is how they are related to the mass energy transfer and mass energy absorption coefficients. Definitions of total and restricted mass stopping powers of directly ionizing radiation are given. The dosimetric quantities, kerma, absorbed dose and exposure together with the relations between them are discussed in depth. Finally it is indicated how the absorbed dose can be measured with a calorimeter by measuringmore » the temperature increase and with an ionisation chamber measuring the charge produced by the ionizing radiation and making use of the Bragg-Gray relation.« less

Radio and Plasma Wave Observations During Cassini's Grand Finale

NASA Astrophysics Data System (ADS)

Kurth, W. S.; Bostrom, R.; Canu, P.; Cecconi, B.; Cornilleau-Wehrlin, N.; Farrell, W. M.; Fischer, G.; Galopeau, P. H. M.; Gurnett, D. A.; Gustafsson, G.; Hospodarsky, G. B.; Lamy, L.; Lecacheux, A.; Louarn, P.; MacDowall, R. J.; Menietti, J. D.; Modolo, R.; Morooka, M.; Pedersen, A.; Persoon, A. M.; Sulaiman, A. H.; Wahlund, J. E.; Ye, S.; Zarka, P. M.

2017-12-01

Cassini ends its 13-year exploration of the Saturnian system in 22 high inclination Grand Finale orbits with perikrones falling between the inner edge of the D ring and the upper limits of Saturn's atmosphere. The Cassini Radio and Plasma Wave Science (RPWS) instrument makes a variety of observations in these unique orbits including Saturn kilometric radiation, plasma waves such as auroral hiss associated with Saturn's auroras, dust via impacts with Cassini, and the upper reaches of Saturn's ionosphere. This paper will provide an overview of the RPWS results from this final phase of the Cassini mission with the unique opportunities afforded by the orbit. Based on early Grand Finale orbits, we can already say that the spacecraft has passed through cyclotron maser source regions of the Saturn kilometric radiation a number of times, found only small amounts of micron-sized dust in the equatorial region, and observed highly variable densities of cold plasma of order 1000 cm-3 in the ionosphere at altitudes of a few thousand km.

The Growing Public Health Challenges of Exposure to Ultraviolet Radiation From Use of Indoor Tanning Devices in the United States.

PubMed

Bowman, Diana M; Lewis, Ryan C; Lee, Maximilian S; Yao, Catherine J

2015-08-01

Ultraviolet radiation is recognized as a human carcinogen by the International Agency for Research on Cancer, the world's authority on cancer research. In particular, exposure to ultraviolet radiation can lead to melanoma of the skin, which is the deadliest form of skin cancer in the United States. Yet despite the significant public health burden that is associated with skin cancer in the United States, each year over a million Americans engage in indoor tanning where exposure to artificial ultraviolet radiation occurs. In this article, we argue for an immediate ban on the use of commercial indoor tanning by minors and, based on international precedents, the phasing out of all commercial tanning operations in the United States. We consider the use of indoor tanning devices in the United States, epidemiological data on indoor tanning devices and cancer, regulation of tanning devices, and scientific evidence for increased government intervention. © The Author(s) 2015.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bahrdt, J.; Follath, R.; Frentrup, W.

Reflections in synchrotron radiation beam lines tend to change the state of polarization of the radiation. This effect is more pronounced for steep angle of incidence, i.e. at low photon energy (say below 100 eV) beam lines. The APPLE II undulator UE112 at BESSY has all four magnetic rows shiftable and thus generates any state of polarization. To provide any intended polarization state at the sample we perform polarization measurements based on simple and fast linear polarization analysis that together with calculations of the undulator radiation predicts undulator settings that cancel beam line polarization effects.

3D numerical calculations and synthetic observations of magnetized massive dense core collapse and fragmentation.

NASA Astrophysics Data System (ADS)

Commerçon, B.; Hennebelle, P.; Levrier, F.; Launhardt, R.; Henning, Th.

2012-03-01

I will present radiation-magneto-hydrodynamics calculations of low-mass and massive dense core collapse, focusing on the first collapse and the first hydrostatic core (first Larson core) formation. The influence of magnetic field and initial mass on the fragmentation properties will be investigated. In the first part reporting low mass dense core collapse calculations, synthetic observations of spectral energy distributions will be derived, as well as classical observational quantities such as bolometric temperature and luminosity. I will show how the dust continuum can help to target first hydrostatic cores and to state about the nature of VeLLOs. Last, I will present synthetic ALMA observation predictions of first hydrostatic cores which may give an answer, if not definitive, to the fragmentation issue at the early Class 0 stage. In the second part, I will report the results of radiation-magneto-hydrodynamics calculations in the context of high mass star formation, using for the first time a self-consistent model for photon emission (i.e. via thermal emission and in radiative shocks) and with the high resolution necessary to resolve properly magnetic braking effects and radiative shocks on scales <100 AU (Commercon, Hennebelle & Henning ApJL 2011). In this study, we investigate the combined effects of magnetic field, turbulence, and radiative transfer on the early phases of the collapse and the fragmentation of massive dense cores (M=100 M_⊙). We identify a new mechanism that inhibits initial fragmentation of massive dense cores, where magnetic field and radiative transfer interplay. We show that this interplay becomes stronger as the magnetic field strength increases. We speculate that highly magnetized massive dense cores are good candidates for isolated massive star formation, while moderately magnetized massive dense cores are more appropriate to form OB associations or small star clusters. Finally we will also present synthetic observations of these collapsing massive dense cores.

BioSentinel: Biosensors for Deep-Space Radiation Study

NASA Technical Reports Server (NTRS)

Lokugamage, Melissa P.; Santa Maria, Sergio R.; Marina, Diana B.; Bhattacharya, Sharmila

2016-01-01

The BioSentinel mission will be deployed on NASA's Exploration Mission 1 (EM-1) in 2018. We will use the budding yeast, Saccharomyces cerevisiae, as a biosensor to study the effect of deep-space radiation on living cells. The BioSentinel mission will be the first investigation of a biological response to space radiation outside Low Earth Orbit (LEO) in over 40 years. Radiation can cause damage such as double stand breaks (DSBs) on DNA. The yeast cell was chosen for this mission because it is genetically controllable, shares homology with human cells in its DNA repair pathways, and can be stored in a desiccated state for long durations. Three yeast strains will be stored dry in multiple microfluidic cards: a wild type control strain, a mutant defective strain that cannot repair DSBs, and a biosensor strain that can only grow if it gets DSB-and-repair events occurring near a specific gene. Growth and metabolic activity of each strain will be measured by a 3-color LED optical detection system. Parallel experiments will be done on the International Space Station and on Earth so that we can compare the results to that of deep space. One of our main objectives is to characterize the microfluidic card activation sequence before the mission. To increase the sensitivity of yeast cells as biosensors, desiccated yeast in each card will be resuspended in a rehydration buffer. After several weeks, the rehydration buffer will be exchanged with a growth medium in order to measure yeast growth and metabolic activity. We are currently working on a time-course experiment to better understand the effects of the rehydration buffer on the response to ionizing radiation. We will resuspend the dried yeast in our rehydration medium over a period of time; then each week, we will measure the viability and ionizing radiation sensitivity of different yeast strains taken from this rehydration buffer. The data obtained in this study will be useful in finalizing the card activation sequence for this mission.

Entanglement of a quantum field with a dispersive medium.

PubMed

Klich, Israel

2012-08-10

In this Letter we study the entanglement of a quantum radiation field interacting with a dielectric medium. In particular, we describe the quantum mixed state of a field interacting with a dielectric through plasma and Drude models and show that these generate very different entanglement behavior, as manifested in the entanglement entropy of the field. We also present a formula for a "Casimir" entanglement entropy, i.e., the distance dependence of the field entropy. Finally, we study a toy model of the interaction between two plates. In this model, the field entanglement entropy is divergent; however, as in the Casimir effect, its distance-dependent part is finite, and the field matter entanglement is reduced when the objects are far.

Optimal low thrust geocentric transfer. [mission analysis computer program

NASA Technical Reports Server (NTRS)

Edelbaum, T. N.; Sackett, L. L.; Malchow, H. L.

1973-01-01

A computer code which will rapidly calculate time-optimal low thrust transfers is being developed as a mission analysis tool. The final program will apply to NEP or SEP missions and will include a variety of environmental effects. The current program assumes constant acceleration. The oblateness effect and shadowing may be included. Detailed state and costate equations are given for the thrust effect, oblateness effect, and shadowing. A simple but adequate model yields analytical formulas for power degradation due to the Van Allen radiation belts for SEP missions. The program avoids the classical singularities by the use of equinoctial orbital elements. Kryloff-Bogoliuboff averaging is used to facilitate rapid calculation. Results for selected cases using the current program are given.

Measurement of the branching fraction of B → Xsγ and ACP in B → Xs + dγ from Belle

NASA Astrophysics Data System (ADS)

Pesántez, L.; Belle Collaboration

2016-04-01

The transitions b → dγ and b → sγ are flavor-changing neutral currents, forbidden at tree level in the Standard Model (SM). These decays proceed via electroweak penguin loop diagrams and can be used to test the SM and new-physics effects. The SM gives very precise predictions when the decays are considered inclusively, for this reason it is important to perform studies where as many final states as possible are reconstructed or where the decay is considered fully inclusively, without explicitly reconstructing the B meson. The large Belle data set of 711fb-1 recorded at the ϒ (4 S) resonance allows for precise measurements of radiative B-decays.

Active media for up-conversion diode-pumped lasers

NASA Astrophysics Data System (ADS)

Tkachuk, Alexandra M.

1996-03-01

In this work, we consider the different methods of populating the initial and final working levels of laser transitions in TR-doped crystals under the selective 'up-conversion' and 'avalanche' diode laser pumping. On the basis of estimates of the probabilities of competing non-radiative energy-transfer processes rates obtained from the experimental data and theoretical calculations, we estimated the efficiency of the up-conversion pumping and selfquenching of the upper TR3+ states excited by laser-diode emission. The effect of the host composition, dopant concentration, and temperature on the output characteristics and up-conversion processes in YLF:Er; BaY2F8:Er; BaY2F8:Er,Yb and BaY2F8:Yb,Ho are determined.

High-energy synchrotron x-ray techniques for studying irradiated materials

DOE PAGES

Park, Jun-Sang; Zhang, Xuan; Sharma, Hemant; ...

2015-03-20

High performance materials that can withstand radiation, heat, multiaxial stresses, and corrosive environment are necessary for the deployment of advanced nuclear energy systems. Nondestructive in situ experimental techniques utilizing high energy x-rays from synchrotron sources can be an attractive set of tools for engineers and scientists to investigate the structure–processing–property relationship systematically at smaller length scales and help build better material models. In this paper, two unique and interconnected experimental techniques, namely, simultaneous small-angle/wide-angle x-ray scattering (SAXS/WAXS) and far-field high-energy diffraction microscopy (FF-HEDM) are presented. Finally, the changes in material state as Fe-based alloys are heated to high temperatures ormore » subject to irradiation are examined using these techniques.« less

Excited atoms in the free-burning Ar arc: treatment of the resonance radiation

NASA Astrophysics Data System (ADS)

Golubovskii, Yu; Kalanov, D.; Gortschakow, S.; Baeva, M.; Uhrlandt, D.

2016-11-01

The collisional-radiative model with an emphasis on the accurate treatment of the resonance radiation transport is developed and applied to the free-burning Ar arc plasma. This model allows for analysis of the influence of resonance radiation on the spatial density profiles of the atoms in different excited states. The comparison of the radial density profiles obtained using an effective transition probability approximation with the results of the accurate solution demonstrates the distinct impact of transport on the profiles and absolute densities of the excited atoms, especially in the arc fringes. The departures from the Saha-Boltzmann equilibrium distributions, caused by different radiative transitions, are analyzed. For the case of the DC arc, the local thermodynamic equilibrium (LTE) state holds close to the arc axis, while strong deviations from the equilibrium state on the periphery occur. In the intermediate radial positions the conditions of partial LTE are fulfilled.

Concentration, physical state, and purity of bacterial endotoxin affect its detoxification by ionizing radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Csako, G.; Tsai, C.M.; Hochstein, H.D.

Increasing concentrations of a highly purified bacterial lipopolysaccharide preparation, the U.S. Reference Standard Endotoxin, were exposed to increasing doses of ionizing radiation from a 60Co source. At identical radiation doses both the structural change and Limulus amebocyte lysate (LAL) reactivity were progressively smaller with increasing concentrations of the lipopolysaccharide in an aqueous medium. Under the experimental conditions used, there was a linear relationship between the endotoxin concentration and radiation dose for the structural changes. In contrast to endotoxin in aqueous medium, endotoxin irradiated in its dry state showed no decrease in LAL reactivity and rabbit pyrogenicity. Endotoxin exposed to radiationmore » in water in the presence of albumin showed a much smaller decrease in LAL and pyrogenic activities than expected. The results show that the concentration, physical state, and purity of endotoxin influence its structural and functional alteration by ionizing radiation.« less

Electromagnetic induction and radiation-induced abnormality of wave propagation in excitable media

NASA Astrophysics Data System (ADS)

Ma, Jun; Wu, Fuqiang; Hayat, Tasawar; Zhou, Ping; Tang, Jun

2017-11-01

Continuous wave emitting from sinus node of the heart plays an important role in wave propagating among cardiac tissue, while the heart beating can be terminated when the target wave is broken into turbulent states by electromagnetic radiation. In this investigation, local periodical forcing is applied on the media to induce continuous target wave in the improved cardiac model, which the effect of electromagnetic induction is considered by using magnetic flux, then external electromagnetic radiation is imposed on the media. It is found that target wave propagation can be blocked to stand in a local area and the excitability of media is suppressed to approach quiescent but homogeneous state when electromagnetic radiation is imposed on the media. The sampled time series for membrane potentials decrease to quiescent state due to the electromagnetic radiation. It could accounts for the mechanism of abnormality in heart failure exposed to continuous electromagnetic field.

Energy structure and radiative lifetimes of InxGa1-xN /AlN quantum dots

NASA Astrophysics Data System (ADS)

Aleksandrov, Ivan A.; Zhuravlev, Konstantin S.

2018-01-01

We report calculations of the ground state transition energies and the radiative lifetimes in InxGa1-xN /AlN quantum dots with different size and indium content. The ground state transition energy and the radiative lifetime of the InxGa1-xN /AlN quantum dots can be varied over a wide range by changing the height of the quantum dot and the indium content. The sizes and compositions for quantum dots emitting in the wavelength range for fiber-optic telecommunications have been found. The radiative lifetime of the InxGa1-xN /AlN quantum dots increases with increase in quantum dot height at a constant indium content, and increases with increase in indium content at constant quantum dot height. For quantum dots with constant ground state transition energy the radiative lifetime decreases with increase in indium content.

Building a New Model of Care for Rapid Breast Radiotherapy Treatment Planning: Evaluation of the Advanced Practice Radiation Therapist in Cavity Delineation.

PubMed

Lee, G; Dinniwell, R; Liu, F F; Fyles, A; Han, K; Conrad, T; Levin, W; Marshall, A; Purdie, T G; Koch, C A

2016-12-01

Breast radiotherapy treatment is commonly managed by a multidisciplinary team to ensure optimal delivery of care. We sought a new model of care whereby a clinical specialist radiation therapist (CSRT) delineates the cavity target for whole breast radiotherapy treatment planning and the radiation oncologist validates the contour during final plan review. This study evaluated the radiation oncologist's acceptance of these contours and identified characteristics of cavities suitable for CSRT-directed contouring. Following specialised breast oncology education and training by the radiation oncologist, the CSRT prospectively delineated cavities in 30 tangential breast radiotherapy cases and consulted the radiation oncologist in 'complex' cases but directed 'non-complex' cases for treatment planning. Changes to CSRT contours were evaluated using the conformity index. Breast density, time since surgery and cavity location, size and visualisation score [CVS: range 1 (no visible cavity) to 5 (homogenous cavity)] were captured. Of the 30 CSRT delineated cavities contours, the CSRT directed 20 (66.7%) cases for planning without radiation oncology review; 19 were accepted (without changes) by the radiation oncologist upon final plan review and one was changed by the radiation oncologist (conformity index = 0.93) for boost treatment and did not affect the tangential treatment plan. Ten (33.3%) cases, all CVS ≤ 3, were reviewed with the radiation oncologist before planning (conformity index = 0.88 ± 0.12). CVS was inversely correlated with breast density and cavity size (P < 0.01). The CSRT delineated cavities appropriate for clinical radiotherapy treatment planning in women with well-visualised cavities, whereas 'complex' cases with dense breast parenchyma, CVS ≤ 3, and/or cases needing boost radiotherapy treatment required review with the radiation oncologist before planning. Copyright © 2016 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

The dynamic Casimir effect within a vibrating metal photonic crystal

NASA Astrophysics Data System (ADS)

Ueta, Tsuyoshi

2014-09-01

The lattice-vibrating metal photonic crystal is exactly a system of dynamical Casimir effect connected in series, and so we can expect that a dynamical Casimir effect is enhanced by the photonic band effect. In the present study, when an electromagnetic field between metal plates is in the ground state in a one-dimensional metal photonic crystal, the radiation of electromagnetic wave in excited states has been investigated by artificially introducing lattice vibration to the photonic crystal. In this case as well as a dynamical Casimir effect, it has been shown that the harmonics of a ground state are generated just by vibrating a photonic crystal even without an incident wave. The dependencies of the radiating power on the number of layers and on the wavenumber of the lattice vibration are remarkable. It has been found that the radiation amplitude on lower excited states is not necessarily large and radiation on specific excited levels is large.

Strong and radiative decays of the doubly charmed baryons

NASA Astrophysics Data System (ADS)

Xiao, Li-Ye; Wang, Kai-Lei; Lü, Qi-Fang; Zhong, Xian-Hui; Zhu, Shi-Lin

2017-11-01

We have systematically studied the strong and radiative decays of the low-lying 1 P -wave doubly charmed baryons. Some interesting observations are: (i) The states Ξcc * and Ωcc * with JP=3 /2+ have a fairly large decay rate into the Ξc cγ and Ωc cγ channels with a width ˜15 and ˜7 keV , respectively. (ii) The lowest lying excited doubly charmed baryons are dominated by the 1 P ρ mode excitations, which should be quite narrow states. They decay into the ground state with JP=1 /2+ through the radiative transitions with a significant ratio. (iii) The total decay widths of the first orbital excitations of λ mode (1 Pλ states with JP=1 /2-, 3 /2-, 5 /2-) are about Γ ˜100 MeV , and the ratio between the radiative and hadronic decay widths is about O (10-3).

Development of Curricula for Nuclear Radiation Protection, Nuclear Instrumentation, and Nuclear Materials Processing Technologies. Final Report.

ERIC Educational Resources Information Center

Hull, Daniel M.

A study was conducted to assist two-year postsecondary educational institutions in providing technical specialty courses for preparing nuclear technicians. As a result of project activities, curricula have been developed for five categories of nuclear technicians and operators: (1) radiation protection technician, (2) nuclear instrumentation and…

Binary black hole merger dynamics and waveforms

NASA Technical Reports Server (NTRS)

Baker, John G.; Centrella, Joan; Choi, Dae-II; Koppitz, Michael; vanMeter, James

2006-01-01

We apply recently developed techniques for simulations of moving black holes to study dynamics and radiation generation in the last few orbits and merger of a binary black hole system. Our analysis produces a consistent picture from the gravitational wave forms and dynamical black hole trajectories for a set of simulations with black holes beginning on circular-orbit trajectories at a variety of initial separations. We find profound agreement at the level of 1% among the simulations for the last orbit, merger and ringdown, resulting in a final black hole with spin parameter a/m = 0.69. Consequently, we are confident that this part of our waveform result accurately represents the predictions from Einstein's General Relativity for the final burst of gravitational radiation resulting from the merger of an astrophysical system of equal-mass non-spinning black holes. We also find good agreement at a level of roughly 10% for the radiation generated in the preceding few orbits.

Investigation of the normal spectral band emissivity characteristic within 7.5 to 13 μm for Molybdenum between 100 and 500 °C

NASA Astrophysics Data System (ADS)

Zhang, Yan; Zhang, Yuzhong; Lu, Rongsheng; Shu, Shuangbao; Lang, Xianli; Yang, Lei

2018-01-01

Molybdenum (Mo) is an important material to construct the first wall for the Experimental Advanced Superconducting Tokamak (EAST). The real-time monitoring of temperature distribution of the first wall based on radiation thermometry is essential to guarantee the stable operation of EAST. So, it is especially important for the acquisition of emissivity property of Mo. In this work, a self-designed emissivity measurement apparatus is developed, and the relationship between the normal infrared spectral band (7.5-13 μm) emissivity of Mo against the temperature and surface roughness of material samples is experimentally investigated under the vacuum condition over the temperature ranging from 100 °C to 500 °C. Moreover, the dependence of spectral band emissivity of Mo exposed to air on the heating-duration time at a given elevated temperature is also studied. The emissivity measurement apparatus is mainly composed of a high temperature furnace and a radiation thermometer as well as a benchmark blackbody furnace. The radiation thermometer is firstly calibrated against the blackbody furnace by means of the multi-temperature methods. And then the temperature of the sample is simultaneously measured by the two highly accurate S-type thermocouples and the radiation thermometer. Finally the emissivity value of the sample is calculated based on the direct radiometric method. The developed emissivity measurement method and experimental results obtained in this work may be helpful to understand the work state the EAST and to use of Mo as an emissivity reference.

Validation of the North American Land Data Assimilation System (NLDAS) retrospective forcing over the southern Great Plains

NASA Astrophysics Data System (ADS)

Luo, Lifeng; Robock, Alan; Mitchell, Kenneth E.; Houser, Paul R.; Wood, Eric F.; Schaake, John C.; Lohmann, Dag; Cosgrove, Brian; Wen, Fenghua; Sheffield, Justin; Duan, Qingyun; Higgins, R. Wayne; Pinker, Rachel T.; Tarpley, J. Dan

2003-11-01

Atmospheric forcing used by land surface models is a critical component of the North American Land Data Assimilation System (NLDAS) and its quality crucially affects the final product of NLDAS and our work on model improvement. A three-year (September 1996-September 1999) retrospective forcing data set was created from the Eta Data Assimilation System and observations and used to run the NLDAS land surface models for this period. We compared gridded NLDAS forcing with station observations obtained from networks including the Oklahoma Mesonet and Atmospheric Radiation Measurement/Cloud and Radiation Testbed at the southern Great Plains. Differences in all forcing variables except precipitation between the NLDAS forcing data set and station observations are small at all timescales. While precipitation data do not agree very well at an hourly timescale, they do agree better at longer timescales because of the way NLDAS precipitation forcing is generated. A small high bias in downward solar radiation and a low bias in downward longwave radiation exist in the retrospective forcing. To investigate the impact of these differences on land surface modeling we compared two sets of model simulations, one forced by the standard NLDAS product and one with station-observed meteorology. The differences in the resulting simulations of soil moisture and soil temperature for each model were small, much smaller than the differences between the models and between the models and observations. This indicates that NLDAS retrospective forcing provides an excellent state-of-the-art data set for land surface modeling, at least over the southern Great Plains region.

Thermal noise in mid-infrared broadband upconversion detectors.

PubMed

Barh, Ajanta; Tidemand-Lichtenberg, Peter; Pedersen, Christian

2018-02-05

Low noise detection with state-of-the-art mid-infrared (MIR) detectors (e.g., PbS, PbSe, InSb, HgCdTe) is a primary challenge owing to the intrinsic thermal background radiation of the low bandgap detector material itself. However, researchers have employed frequency upconversion based detectors (UCD), operable at room temperature, as a promising alternative to traditional direct detection schemes. UCD allows for the use of a low noise silicon-CCD/camera to improve the SNR. Using UCD, the noise contributions from the nonlinear material itself should be evaluated in order to estimate the limits of the noise-equivalent power of an UCD system. In this article, we rigorously analyze the optical power generated by frequency upconversion of the intrinsic black-body radiation in the nonlinear material itself due to the crystals residual emissivity, i.e. absorption. The thermal radiation is particularly prominent at the optical absorption edge of the nonlinear material even at room temperature. We consider a conventional periodically poled lithium niobate (PPLN) based MIR-UCD for the investigation. The UCD is designed to cover a broad spectral range, overlapping with the entire absorption edge of the PPLN (3.5 - 5 µm). Finally, an upconverted thermal radiation power of ~30 pW at room temperature (~30°C) and a maximum of ~70 pW at 120°C of the PPLN crystal are measured for a CW mixing beam of power ~60 W, supporting a good quantitative agreement with the theory. The analysis can easily be extended to other popular nonlinear conversion processes including OPO, DFG, and SHG.

Modeling of radiative properties of Sn plasmas for extreme-ultraviolet source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sasaki, Akira; Sunahara, Atsushi; Furukawa, Hiroyuki

Atomic processes in Sn plasmas are investigated for application to extreme-ultraviolet (EUV) light sources used in microlithography. We develop a full collisional radiative (CR) model of Sn plasmas based on calculated atomic data using Hebrew University Lawrence Livermore Atomic Code (HULLAC). Resonance and satellite lines from singly and multiply excited states of Sn ions, which contribute significantly to the EUV emission, are identified and included in the model through a systematic investigation of their effect on the emission spectra. The wavelengths of the 4d-4f+4p-4d transitions of Sn{sup 5+} to Sn{sup 13+} are investigated, because of their importance for determining themore » conversion efficiency of the EUV source, in conjunction with the effect of configuration interaction in the calculation of atomic structure. Calculated emission spectra are compared with those of charge exchange spectroscopy and of laser produced plasma EUV sources. The comparison is also carried out for the opacity of a radiatively heated Sn sample. A reasonable agreement is obtained between calculated and experimental EUV emission spectra observed under the typical condition of EUV sources with the ion density and ionization temperature of the plasma around 10{sup 18} cm{sup -3} and 20 eV, respectively, by applying a wavelength correction to the resonance and satellite lines. Finally, the spectral emissivity and opacity of Sn plasmas are calculated as a function of electron temperature and ion density. The results are useful for radiation hydrodynamics simulations for the optimization of EUV sources.« less

Towards a Realistic Pulsar Magnetosphere

NASA Technical Reports Server (NTRS)

Kalapotharakos, Constantinos; Kazanas, Demosthenes; Harding, Alice; Contopoulos, Ioannis

2012-01-01

We present the magnetic and electric field structures as well as the currents ami charge densities of pulsar magnetospberes which do not obey the ideal condition, E(raised dot) B = O. Since the acceleration of particles and the production of radiation requires the presence of an electric field component parallel to the magnetic field, E(sub ll) the structure of non-Ideal pulsar magnetospheres is intimately related to the production of pulsar radiation. Therefore, knowledge of the structure of non-Ideal pulsar maglletospheres is important because their comparison (including models for t he production of radiation) with observations will delineate the physics and the parameters underlying the pulsar radiation problem. We implement a variety of prescriptions that support nonzero values for E(sub ll) and explore their effects on the structure of the resulting magnetospheres. We produce families of solutions that span the entire range between the vacuum and the (ideal) Force-Free Electrodynamic solutions. We also compute the amount of dissipation as a fraction of the Poynting flux for pulsars of different angles between the rotation and magnetic axes and conclude that tltis is at most 20-40% (depending on t he non-ideal prescription) in the aligned rotator and 10% in the perpendicular one. We present also the limiting solutions with the property J = pc and discuss their possible implicatioll on the determination of the "on/ off" states of the intermittent pulsars. Finally, we find that solutions with values of J greater than those needed to null E(sub ll) locally produce oscillations, potentially observable in the data.

Radiation exposure of air carrier crewmembers II.

DOT National Transportation Integrated Search

1992-01-01

The cosmic radiation environment at air carrier flight altitudes is described and estimates given of the amounts of galactic cosmic radiation received on a wide variety of routes to and from, and within the contiguous United States. Radiation exposur...

PHYSICAL FUNDAMENTALS OF QUANTUM ELECTRONICS: Interaction of a sequence of short broad-band radiation pulses with a diatomic molecule

NASA Astrophysics Data System (ADS)

Oraevsky, Anatolii N.; Kozlovskii, Andrei V.; Chichkov, B. N.

1998-07-01

A theoretical analysis is made of the process in which a molecule undergoes a transition between the ground and excited electronic states under the action of a radiation pulse and then, in the interpulse interval, returns to the ground electronic state. Such a periodic process is important in the cooling of molecules by laser radiation. It is shown that the radiation parameters can be selected so that the CO and CN molecules experience over 1000 excitation—relaxation events without dissociation.

Quantum radiation produced by the entanglement of quantum fields

NASA Astrophysics Data System (ADS)

Iso, Satoshi; Oshita, Naritaka; Tatsukawa, Rumi; Yamamoto, Kazuhiro; Zhang, Sen

2017-01-01

We investigate the quantum radiation produced by an Unruh-De Witt detector in a uniformly accelerating motion coupled to the vacuum fluctuations. Quantum radiation is nonvanishing, which is consistent with the previous calculation by Lin and Hu [Phys. Rev. D 73, 124018 (2006), 10.1103/PhysRevD.73.124018]. We infer that this quantum radiation from the Unruh-De Witt detector is generated by the nonlocal correlation of the Minkowski vacuum state, which has its origin in the entanglement of the state between the left and the right Rindler wedges.

Overview of the NASA space radiation laboratory

DOE Office of Scientific and Technical Information (OSTI.GOV)

La Tessa, Chiara; Sivertz, Michael; Chiang, I-Hung

The NASA Space Radiation Laboratory (NSRL) is a multidisciplinary center for space radiation research funded by NASA and located at the Brookhaven National Laboratory (BNL), Upton NY. Operational since 2003, the scope of NSRL is to provide ion beams in support of the NASA Humans in Space program in radiobiology, physics and engineering to measure the risk and ameliorate the effect of radiation in space. Recently, it has also been recognized as the only facility in the U.S. currently capable of contributing to heavy ion radiotherapy research. Finally, this work contains a general overview of NSRL structure, capabilities and operation.

Overview of the NASA space radiation laboratory

DOE PAGES

La Tessa, Chiara; Sivertz, Michael; Chiang, I-Hung; ...

2016-11-11

The NASA Space Radiation Laboratory (NSRL) is a multidisciplinary center for space radiation research funded by NASA and located at the Brookhaven National Laboratory (BNL), Upton NY. Operational since 2003, the scope of NSRL is to provide ion beams in support of the NASA Humans in Space program in radiobiology, physics and engineering to measure the risk and ameliorate the effect of radiation in space. Recently, it has also been recognized as the only facility in the U.S. currently capable of contributing to heavy ion radiotherapy research. Finally, this work contains a general overview of NSRL structure, capabilities and operation.

Evaluation of radiation exposure from diagnostic radiology examination; availability of final recommendations--FDA. Notice.

PubMed

1986-02-19

The Food and Drug Administration (FDA) is announcing the availability of a document entitled "Recommendations for Evaluation of Radiation Exposure from Diagnostic Radiology Examinations". The recommendations, prepared by FDA's Center for Devices and Radiological Health (CDRH), encourage diagnostic radiology facilities to take voluntary action to: Become aware of the radiation levels experienced by patients undergoing the projections commonly given in the facility; compare their radiation levels to generally accepted levels for these projections; and bring the exposures back into line if their levels fall consistently outside these generally accepted levels.

75 FR 17857 - Removal of Obsolete References to Herbicides Containing Dioxin

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-08

... Herbicides Containing Dioxin AGENCY: Department of Veterans Affairs. ACTION: Final rule. SUMMARY: The... health effects of exposure to herbicides containing dioxin and radiation to remove the obsolete references to herbicides containing dioxin. This final rule reflects changes made by the Agent Orange Act of...

In-Medium Parton Branching Beyond Eikonal Approximation

NASA Astrophysics Data System (ADS)

Apolinário, Liliana

2017-03-01

The description of the in-medium modifications of partonic showers has been at the forefront of current theoretical and experimental efforts in heavy-ion collisions. It provides a unique laboratory to extend our knowledge frontier of the theory of the strong interactions, and to assess the properties of the hot and dense medium (QGP) that is produced in ultra-relativistic heavy-ion collisions at RHIC and the LHC. The theory of jet quenching, a commonly used alias for the modifications of the parton branching resulting from the interactions with the QGP, has been significantly developed over the last years. Within a weak coupling approach, several elementary processes that build up the parton shower evolution, such as single gluon emissions, interference effects between successive emissions and corrections to radiative energy loss of massive quarks, have been addressed both at eikonal accuracy and beyond by taking into account the Brownian motion that high-energy particles experience when traversing a hot and dense medium. In this work, by using the setup of single gluon emission from a color correlated quark-antiquark pair in a singlet state (qbar{q} antenna), we calculate the in-medium gluon radiation spectrum beyond the eikonal approximation. The results show that we are able to factorize broadening effects from the modifications of the radiation process itself. This constitutes the final proof that a probabilistic picture of the parton shower evolution holds even in the presence of a QGP.

Predictability of Solar Radiation for Photovoltaics systems over Europe: from short-term to seasonal time-scales

NASA Astrophysics Data System (ADS)

De Felice, Matteo; Petitta, Marcello; Ruti, Paolo

2014-05-01

Photovoltaic diffusion is steadily growing on Europe, passing from a capacity of almost 14 GWp in 2011 to 21.5 GWp in 2012 [1]. Having accurate forecast is needed for planning and operational purposes, with the possibility to model and predict solar variability at different time-scales. This study examines the predictability of daily surface solar radiation comparing ECMWF operational forecasts with CM-SAF satellite measurements on the Meteosat (MSG) full disk domain. Operational forecasts used are the IFS system up to 10 days and the System4 seasonal forecast up to three months. Forecast are analysed considering average and variance of errors, showing error maps and average on specific domains with respect to prediction lead times. In all the cases, forecasts are compared with predictions obtained using persistence and state-of-art time-series models. We can observe a wide range of errors, with the performance of forecasts dramatically affected by orography and season. Lower errors are on southern Italy and Spain, with errors on some areas consistently under 10% up to ten days during summer (JJA). Finally, we conclude the study with some insight on how to "translate" the error on solar radiation to error on solar power production using available production data from solar power plants. [1] EurObserver, "Baromètre Photovoltaïque, Le journal des énergies renouvables, April 2012."

Improving the radiation hardness of graphene field effect transistors

DOE PAGES

Alexandrou, Konstantinos; Masurkar, Amrita; Edrees, Hassan; ...

2016-10-11

Ionizing radiation poses a significant challenge to the operation and reliability of conventional silicon-based devices. In this paper, we report the effects of gamma radiation on graphene field-effect transistors (GFETs), along with a method to mitigate those effects by developing a radiation-hardened version of our back-gated GFETs. We demonstrate that activated atmospheric oxygen from the gamma ray interaction with air damages the semiconductor device, and damage to the substrate contributes additional threshold voltage instability. Our radiation-hardened devices, which have protection against these two effects, exhibit minimal performance degradation, improved stability, and significantly reduced hysteresis after prolonged gamma radiation exposure. Finally,more » we believe this work provides an insight into graphene's interactions with ionizing radiation that could enable future graphene-based electronic devices to be used for space, military, and other radiation-sensitive applications.« less

Improving the radiation hardness of graphene field effect transistors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alexandrou, Konstantinos; Masurkar, Amrita; Edrees, Hassan

Ionizing radiation poses a significant challenge to the operation and reliability of conventional silicon-based devices. In this paper, we report the effects of gamma radiation on graphene field-effect transistors (GFETs), along with a method to mitigate those effects by developing a radiation-hardened version of our back-gated GFETs. We demonstrate that activated atmospheric oxygen from the gamma ray interaction with air damages the semiconductor device, and damage to the substrate contributes additional threshold voltage instability. Our radiation-hardened devices, which have protection against these two effects, exhibit minimal performance degradation, improved stability, and significantly reduced hysteresis after prolonged gamma radiation exposure. Finally,more » we believe this work provides an insight into graphene's interactions with ionizing radiation that could enable future graphene-based electronic devices to be used for space, military, and other radiation-sensitive applications.« less

Expanding the scope of practice for radiology managers: radiation safety duties.

PubMed

Orders, Amy B; Wright, Donna

2003-01-01

In addition to financial responsibilities and patient care duties, many medical facilities also expect radiology department managers to wear "safety" hats and complete fundamental quality control/quality assurance, conduct routine safety surveillance in the department, and to meet regulatory demands in the workplace. All managers influence continuous quality improvement initiatives, from effective utilization of resource and staffing allocations, to efficacy of patient scheduling tactics. It is critically important to understand continuous quality improvement (CQI) and its relationship with the radiology manager, specifically quality assurance/quality control in routine work, as these are the fundamentals of institutional safety, including radiation safety. When an institution applies for a registration for radiation-producing devices or a license for the use of radioactive materials, the permit granting body has specific requirements, policies and procedures that must be satisfied in order to be granted a permit and to maintain it continuously. In the 32 U.S. Agreement states, which are states that have radiation safety programs equivalent to the Nuclear Regulatory Commission programs, individual facilities apply for permits through the local governing body of radiation protection. Other states are directly licensed by the Nuclear Regulatory Commission and associated regulatory entities. These regulatory agencies grant permits, set conditions for use in accordance with state and federal laws, monitor and enforce radiation safety activities, and audit facilities for compliance with their regulations. Every radiology department and associated areas of radiation use are subject to inspection and enforcement policies in order to ensure safety of equipment and personnel. In today's business practice, department managers or chief technologists may actively participate in the duties associated with institutional radiation safety, especially in smaller institutions, while other facilities may assign the duties and title of "radiation safety officer" to a radiologist or other management, per the requirements of regulatory agencies in that state. Radiation safety in a medical setting can be delineated into two main categories--equipment and personnel requirements--each having very specific guidelines. The literature fails to adequately address the blatant link between radiology department managers and radiation safety duties. The breadth and depth of this relationship is of utmost concern and warrants deeper insight as the demands of the regulatory agencies increase with the new advances in technology, procedures and treatments associated with radiation-producing devices and radioactive materials.

Machine detector interface studies: Layout and synchrotron radiation estimate in the future circular collider interaction region

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boscolo, Manuela; Burkhardt, Helmut; Sullivan, Michael

The interaction region layout for the e +e – future circular collider FCC-ee is presented together with a preliminary estimate of synchrotron radiation that affects this region. We describe in this paper the main guidelines of this design and the estimate of synchrotron radiation coming from the last bending magnets and from the final focus quadrupoles, with the software tools developed for this purpose. Here, the design follows the asymmetric optics layout as far as incoming bend radiation is concerned with the maximum foreseen beam energy of 175 GeV and we present a feasible initial layout with an indication ofmore » tolerable synchrotron radiation.« less

Machine detector interface studies: Layout and synchrotron radiation estimate in the future circular collider interaction region

DOE PAGES

Boscolo, Manuela; Burkhardt, Helmut; Sullivan, Michael

2017-01-27

The interaction region layout for the e +e – future circular collider FCC-ee is presented together with a preliminary estimate of synchrotron radiation that affects this region. We describe in this paper the main guidelines of this design and the estimate of synchrotron radiation coming from the last bending magnets and from the final focus quadrupoles, with the software tools developed for this purpose. Here, the design follows the asymmetric optics layout as far as incoming bend radiation is concerned with the maximum foreseen beam energy of 175 GeV and we present a feasible initial layout with an indication ofmore » tolerable synchrotron radiation.« less

Development and Verification of Enclosure Radiation Capabilities in the CHarring Ablator Response (CHAR) Code

NASA Technical Reports Server (NTRS)

Salazar, Giovanni; Droba, Justin C.; Oliver, Brandon; Amar, Adam J.

2016-01-01

With the recent development of multi-dimensional thermal protection system (TPS) material response codes, the capability to account for surface-to-surface radiation exchange in complex geometries is critical. This paper presents recent efforts to implement such capabilities in the CHarring Ablator Response (CHAR) code developed at NASA's Johnson Space Center. This work also describes the different numerical methods implemented in the code to compute geometric view factors for radiation problems involving multiple surfaces. Verification of the code's radiation capabilities and results of a code-to-code comparison are presented. Finally, a demonstration case of a two-dimensional ablating cavity with enclosure radiation accounting for a changing geometry is shown.

Pathophysiology, Diagnosis, and Treatment of Radiation Necrosis in the Brain

PubMed Central

MIYATAKE, Shin-Ichi; NONOGUCHI, Noasuke; FURUSE, Motomasa; YORITSUNE, Erina; MIYATA, Tomo; KAWABATA, Shinji; KUROIWA, Toshihiko

2015-01-01

New radiation modalities have made it possible to prolong the survival of individuals with malignant brain tumors, but symptomatic radiation necrosis becomes a serious problem that can negatively affect a patient’s quality of life through severe and lifelong effects. Here we review the relevant literature and introduce our original concept of the pathophysiology of brain radiation necrosis following the treatment of brain, head, and neck tumors. Regarding the pathophysiology of radiation necrosis, we introduce two major hypotheses: glial cell damage or vascular damage. For the differential diagnosis of radiation necrosis and tumor recurrence, we focus on the role of positron emission tomography. Finally, in accord with our hypothesis regarding the pathophysiology, we describe the promising effects of the anti-vascular endothelial growth factor antibody bevacizumab on symptomatic radiation necrosis in the brain. PMID:25744350

Investigation of the radiation background in the interaction region of the medium-energy electron relativisitic heavy ion collider (MeRHIC)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beebe-Wang,J.

There are three main sources of the radiation background in MeRHIC: forward synchrotron radiation generated upstream of the detector, the direct backward radiation caused by the photons hitting beampipe downstream of the detector, and the indirect secondary radiation caused by hard photons hitting vacuum systems, masks, collimators, absorbers or any other elements in the interaction region. In this paper, we first calculate the primary radiation distribution by employing electromagnetic theory. Then we obtain the direct backward scattering rate by applying the kinematic Born approximation deduced from scattering dynamics. The diffuse scattering cross section is calculated as a function of themore » surface properties of the MeRHIC vacuum system. Finally, the dominating physical processes and minimization of indirect secondary radiation is presented and discussed.« less

Covariability in the Monthly Mean Convective and Radiative Diurnal Cycles in the Amazon

NASA Technical Reports Server (NTRS)

Dodson, Jason B.; Taylor, Patrick C.

2015-01-01

The diurnal cycle of convective clouds greatly influences the radiative energy balance in convectively active regions of Earth, through both direct presence, and the production of anvil and stratiform clouds. Previous studies show that the frequency and properties of convective clouds can vary on monthly timescales as a result of variability in the monthly mean atmospheric state. Furthermore, the radiative budget in convectively active regions also varies by up to 7 Wm-2 in convectively active regions. These facts suggest that convective clouds connect atmospheric state variability and radiation variability beyond clear sky effects alone. Previous research has identified monthly covariability between the diurnal cycle of CERES-observed top-of-atmosphere radiative fluxes and multiple atmospheric state variables from reanalysis over the Amazon region. ASVs that enhance (reduce) deep convection, such as CAPE (LTS), tend to shift the daily OLR and cloud albedo maxima earlier (later) in the day by 2-3 hr. We first test the analysis method using multiple reanalysis products for both the dry and wet seasons to further investigate the robustness of the preliminary results. We then use CloudSat data as an independent cloud observing system to further evaluate the relationships of cloud properties to variability in radiation and atmospheric states. While CERES can decompose OLR variability into clear sky and cloud effects, it cannot determine what variability in cloud properties lead to variability in the radiative cloud effects. Cloud frequency, cloud top height, and cloud microphysics all contribute to the cloud radiative effect, all of which are observable by CloudSat. In addition, CloudSat can also observe the presence and variability of deep convective cores responsible for the production of anvil clouds. We use these capabilities to determine the covariability of convective cloud properties and the radiative diurnal cycle.

MONITORING ENVIRONMENTAL RADIATION IN THE UNITED STATES(RADNET)

EPA Science Inventory

Operate a national network of sampling stations that regularly submit environmental samples of air, precipitation and drinking water; analyze all samples for radiation at the laboratory; and report data to the public and the radiation protection community. During national radiat...

Education and Training Needs in Radiation Oncology in India: Opportunities for Indo–US Collaborations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grover, Surbhi, E-mail: Surbhi.grover@uphs.upenn.edu; Chadha, Manjeet; Rengan, Ramesh

Purpose: To conduct a survey of radiation oncologists in India, to better understand specific educational needs of radiation oncology in India and define areas of collaboration with US institutions. Methods and Materials: A 20-question survey was distributed to members of the Association of Indian Radiation Oncologists and the Indian Brachytherapy Society between November 2013 and May 2014. Results: We received a total of 132 responses. Over 50% of the physicians treat more than 200 patients per day, use 2-dimensional or 3-dimensional treatment planning techniques, and approximately 50% use image guided techniques. For education needs, most respondents agreed that further education inmore » intensity modulated radiation therapy, image guided radiation therapy, stereotactic radiation therapy, biostatistics, and research methods for medical residents would be useful areas of collaboration with institutions in the United States. Other areas of collaboration include developing a structured training module for nursing, physics training, and developing a second-opinion clinic for difficult cases with faculty in the United States. Conclusion: Various areas of potential collaboration in radiation oncology education were identified through this survey. These include the following: establishing education programs focused on current technology, facilitating exchange programs for trainees in India to the United States, promoting training in research methods, establishing training modules for physicists and oncology nurses, and creating an Indo–US. Tumor Board. It would require collaboration between the Association of Indian Radiation Oncologists and the American Society for Radiation Oncology to develop these educational initiatives.« less

Education and Training Needs in Radiation Oncology in India: Opportunities for Indo-US Collaborations.

PubMed

Grover, Surbhi; Chadha, Manjeet; Rengan, Ramesh; Williams, Tim R; Morris, Zachary S; Morgan, David A L; Tripuraneni, Prabhakar; Hu, Kenneth; Viswanathan, Akila N

2015-12-01

To conduct a survey of radiation oncologists in India, to better understand specific educational needs of radiation oncology in India and define areas of collaboration with US institutions. A 20-question survey was distributed to members of the Association of Indian Radiation Oncologists and the Indian Brachytherapy Society between November 2013 and May 2014. We received a total of 132 responses. Over 50% of the physicians treat more than 200 patients per day, use 2-dimensional or 3-dimensional treatment planning techniques, and approximately 50% use image guided techniques. For education needs, most respondents agreed that further education in intensity modulated radiation therapy, image guided radiation therapy, stereotactic radiation therapy, biostatistics, and research methods for medical residents would be useful areas of collaboration with institutions in the United States. Other areas of collaboration include developing a structured training module for nursing, physics training, and developing a second-opinion clinic for difficult cases with faculty in the United States. Various areas of potential collaboration in radiation oncology education were identified through this survey. These include the following: establishing education programs focused on current technology, facilitating exchange programs for trainees in India to the United States, promoting training in research methods, establishing training modules for physicists and oncology nurses, and creating an Indo-US. Tumor Board. It would require collaboration between the Association of Indian Radiation Oncologists and the American Society for Radiation Oncology to develop these educational initiatives. Copyright © 2015 Elsevier Inc. All rights reserved.

Reconstructing WIMP properties through an interplay of signal measurements in direct detection, Fermi-LAT, and CTA searches for dark matter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roszkowski, Leszek; Sessolo, Enrico Maria; Trojanowski, Sebastian

2016-08-01

We examine the projected ability to reconstruct the mass, scattering, and annihilation cross section of dark matter in the new generation of large underground detectors, XENON-1T, SuperCDMS, and DarkSide-G2, in combination with diffuse gamma radiation from expected 15 years of data from Fermi-LAT observation of 46 local spiral dwarf galaxies and projected CTA sensitivity to a signal from the Galactic Center. To this end we consider several benchmark points spanning a wide range of WIMP mass, different annihilation final states, and large enough event rates to warrant detection in one or more experiments. As previously shown, below some 100 GeVmore » only direct detection experiments will in principle be able to reconstruct WIMP mass well. This may, in case a signal at Fermi-LAT is also detected, additionally help restricting σ v and the allowed decay branching rates. In the intermediate range between some 100 GeV and up a few hundred GeV, direct and indirect detection experiments can be used in complementarity to ameliorate the respective determinations, which in individual experiments can at best be rather poor, thus making the WIMP reconstruction in this mass range very challenging. At large WIMP mass, ∼ 1 TeV, CTA will have the ability to reconstruct mass, annihilation cross section, and the allowed decay branching rates to very good precision for the τ{sup +}τ{sup -} or purely leptonic final state, good for the W {sup +} W {sup -} case, and rather poor for b b-bar . A substantial improvement can potentially be achieved by reducing the systematic uncertainties, increasing exposure, or by an additional measurement at Fermi-LAT that would help reconstruct the annihilation cross section and the allowed branching fractions to different final states.« less

Technology Development of Miniaturized Far-Infrared Sources for Biomolecular Spectroscopy

NASA Technical Reports Server (NTRS)

Kono, Junichiro

2003-01-01

The objective of this project was to develop a purely solid-state based, thus miniaturized, far-infrared (FIR) (also known as terahertz (THz)) wave source using III-V semiconductor nanostructures for biomolecular detection and sensing. Many biomolecules, such as DNA and proteins, have distinct spectroscopic features in the FIR wavelength range as a result of vibration-rotation-tunneling motions and various inter- and intra-molecule collective motions. Spectroscopic characterization of such molecules requires narrow linewidth, sufficiently high power, tunable (in wavelength), and coherent FIR sources. Unfortunately, the FIR frequency is one of the least technologically developed ranges in the electromagnetic spectrum. Currently available FIR sources based on non-solid state technology are bulky, inefficient, and very often incoherent. In this project we investigated antimonide based compound semiconductor (ABCS) nanostructures as the active medium to generate FIR radiation. The final goal of this project was to demonstrate a semiconductor THz source integrated with a pumping diode laser module to achieve a compact system for biomolecular applications.

Search for the electroweak production of supersymmetric particles in $$\\sqrt{s}$$ = 8 TeV $pp$ collisions with the ATLAS detector

DOE PAGES

Aad, G.; Abbott, B.; Abdallah, J.; ...

2016-03-04

In this study, the ATLAS experiment has performed extensive searches for the electroweak production of charginos, neutralinos, and staus. This article summarizes and extends the search for electroweak supersymmetry with new analyses targeting scenarios not covered by previously published searches. New searches use vector-boson fusion production, initial-state radiation jets, and low-momentum lepton final states, as well as multivariate analysis techniques to improve the sensitivity to scenarios with small mass splittings and low-production cross sections. Results are based on 20 fb -1 of proton-proton collision data at √s = 8 TeV recorded with the ATLAS experiment at the Large Hadron Collider.more » No significant excess beyond Standard Model expectations is observed. The new and existing searches are combined and interpreted in terms of 95% confidence-level exclusion limits in simplified models, where a single production process and decay mode is assumed, as well as within phenomenological supersymmetric models.« less

Simulation of π 0-γ separation study for proposed CMS forward electromagnetic calorimeter

DOE PAGES

Roy, Ashim; Jain, Shilpi; Banerjee, Sunanda; ...

2016-11-11

The Forward Electromagnetic Calorimeter of the CMS detector is going to be upgraded in the high luminosity running as the energy of the present Electromagnetic Calorimeter (PbWO4) will degrade in the high luminosity (luminosity 10 34 cm -2 s -1) running due to extensive radiation (hadron flux 10 13 neutrons cm, -2). Shashlik Electromagnetic Calorimeter which consists of alternate layers of 1.5 mm LYSO(Ce) crystal plates and 2.5 mm Tungsten absorbers, was a proposal for high luminosity running. One of the performance points for any electromagnetic calorimeter is the ability to separate π 0 s from true photons, since finalmore » states with photons are a clean and one of the most important final states in proton-proton collisions at the LHC. As a result, the objective of this project is to study the possibility of π 0 and γ separation in the Shashlik detector using Multivariate Analysis (MVA) technique.« less

Simulation of π 0-γ separation study for proposed CMS forward electromagnetic calorimeter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roy, Ashim; Jain, Shilpi; Banerjee, Sunanda

The Forward Electromagnetic Calorimeter of the CMS detector is going to be upgraded in the high luminosity running as the energy of the present Electromagnetic Calorimeter (PbWO4) will degrade in the high luminosity (luminosity 10 34 cm -2 s -1) running due to extensive radiation (hadron flux 10 13 neutrons cm, -2). Shashlik Electromagnetic Calorimeter which consists of alternate layers of 1.5 mm LYSO(Ce) crystal plates and 2.5 mm Tungsten absorbers, was a proposal for high luminosity running. One of the performance points for any electromagnetic calorimeter is the ability to separate π 0 s from true photons, since finalmore » states with photons are a clean and one of the most important final states in proton-proton collisions at the LHC. As a result, the objective of this project is to study the possibility of π 0 and γ separation in the Shashlik detector using Multivariate Analysis (MVA) technique.« less

A Kinetic Approach to Propagation and Stability of Detonation Waves

NASA Astrophysics Data System (ADS)

Monaco, R.; Bianchi, M. Pandolfi; Soares, A. J.

2008-12-01

The problem of the steady propagation and linear stability of a detonation wave is formulated in the kinetic frame for a quaternary gas mixture in which a reversible bimolecular reaction takes place. The reactive Euler equations and related Rankine-Hugoniot conditions are deduced from the mesoscopic description of the process. The steady propagation problem is solved for a Zeldovich, von Neuman and Doering (ZND) wave, providing the detonation profiles and the wave thickness for different overdrive degrees. The one-dimensional stability of such detonation wave is then studied in terms of an initial value problem coupled with an acoustic radiation condition at the equilibrium final state. The stability equations and their initial data are deduced from the linearized reactive Euler equations and related Rankine-Hugoniot conditions through a normal mode analysis referred to the complex disturbances of the steady state variables. Some numerical simulations for an elementary reaction of the hydrogen-oxygen chain are proposed in order to describe the time and space evolution of the instabilities induced by the shock front perturbation.

Computation of Radiation Heat Transfer in Aeroengine Combustors

NASA Technical Reports Server (NTRS)

Patankar, S. V.

1996-01-01

In this report the highlights of the research completed for the NASA are summarized. This research has been completed in the form of two Ph.D. theses by Chai (1994) and Parthasarathy (1996). Readers are referred to these theses for a complete details of the work and lists of references. In the following sections, first objectives of this research are introduced, then the finite-volume method for radiation heat transfer is described, and finally computations of radiative heat transfer in non-gray participating media is presented.

Practical question-and-answer guide on VDTS (video display terminals) for BEES (base bioenvironmental engineer). Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Olson, B.M.

1985-01-01

The USAF OEHL conducted an extensive literature review of Video Display Terminals (VDTs) and the health problems commonly associated with them. The report is presented in a question-and-answer format in an attempt to paraphrase the most commonly asked questions about VDTs that are forwarded to USAF OEHL/RZN. The questions and answers have been divided into several topic areas: Ionizing Radiation; Nonionizing Radiation; Optical Radiation; Ultrasound; Static Electricity; Health Complaints/Ergonomics; Pregnancy.

[RADIATION SAFETY DURING REMEDIATION OF THE "SEVRAO" FACILITIES].

PubMed

Shandala, N K; Kiselev, S M; Titov, A V; Simakov, A V; Seregin, V A; Kryuchkov, V P; Bogdanova, L S; Grachev, M I

2015-01-01

Within a framework of national program on elimination of nuclear legacy, State Corporation "Rosatom" is working on rehabilitation at the temporary waste storage facility at Andreeva Bay (Northwest Center for radioactive waste "SEVRAO"--the branch of "RosRAO"), located in the North-West of Russia. In the article there is presented an analysis of the current state of supervision for radiation safety of personnel and population in the context of readiness of the regulator to the implementation of an effective oversight of radiation safety in the process of radiation-hazardous work. Presented in the article results of radiation-hygienic monitoring are an informative indicator of the effectiveness of realized rehabilitation measures and characterize the radiation environment in the surveillance zone as a normal, without the tendency to its deterioration.

Control of excessive lead exposure in radiator repair workers.

PubMed

1991-03-01

In 1988, 83 automotive repair workers with blood lead levels (BLLs) greater than 25 micrograms/dL were reported to state health departments in the seven states that collaborated with CDC's National Institute for Occupational Safety and Health (NIOSH) in maintaining registries of elevated BLLs in adults. In 18 (22%) of these 83 persons, BLLs were greater than 50 micrograms/dL. Among automotive repair workers for whom a job category was specified, radiator repair work was the principal source of lead exposure. The major sources of exposure for radiator repair workers are lead fumes generated during soldering and lead dust produced during radiator cleaning. This report summarizes current BLL surveillance data for radiator repair workers and describes three control technologies that are effective in reducing lead exposures in radiator repair shops.

Radiation tests on optical fibres: good and bad practice

NASA Astrophysics Data System (ADS)

Kuhnhenn, J.

2017-11-01

Testing optical fibers for their response to ionizing radiation is unavoidable if their properties in radiation environments need to be known. So far, no model exists that would be able to predict the behavior of optical fibers in the presence of radiation, for example because too many, mostly unknown parameters influence the changes in the fiber. To obtain reliable results from irradiation tests of optical fibers a well-defined setup and thorough experience is needed to avoid erroneous data that might lead to wrong decisions for the final application. This presentation tries to introduce basic concepts of radiation testing of optical fibers, focusing on not so well known influences or typical errors. Focus will be laid on the measurement of radiation-induced attenuation (RIA) in optical fibers.

Design and qualification of the SEU/TD Radiation Monitor chip

NASA Technical Reports Server (NTRS)

Buehler, Martin G.; Blaes, Brent R.; Soli, George A.; Zamani, Nasser; Hicks, Kenneth A.

1992-01-01

This report describes the design, fabrication, and testing of the Single-Event Upset/Total Dose (SEU/TD) Radiation Monitor chip. The Radiation Monitor is scheduled to fly on the Mid-Course Space Experiment Satellite (MSX). The Radiation Monitor chip consists of a custom-designed 4-bit SRAM for heavy ion detection and three MOSFET's for monitoring total dose. In addition the Radiation Monitor chip was tested along with three diagnostic chips: the processor monitor and the reliability and fault chips. These chips revealed the quality of the CMOS fabrication process. The SEU/TD Radiation Monitor chip had an initial functional yield of 94.6 percent. Forty-three (43) SEU SRAM's and 14 Total Dose MOSFET's passed the hermeticity and final electrical tests and were delivered to LL.

Comprehensive Review of Ultraviolet Radiation and the Current Status on Sunscreens

PubMed Central

Moon, Summer; Armstrong, Frank

2012-01-01

In the past, manufacturers’ labeling of sunscreen varied greatly, confusing the consumers regarding efficacy and the appropriate photoprotection provided by their products. Therefore, in June 2011, the United States Food and Drug Administration issued new guidelines for sunscreen labeling. Sunscreen products are over-the-counter drugs; therefore, they are regulated by the United States Food and Drug Administration to determine safety, efficacy, and labeling. This article discusses ultraviolet radiation and the positive and negative effects of ultraviolet radiation, provides a review of sunscreens, and discusses the new United States Food and Drug Administration regulations for sunscreens. PMID:23050030

Measurement of jet activity produced in top-quark events with an electron, a muon and two b-tagged jets in the final state in pp collisions at [Formula: see text] TeV with the ATLAS detector.

PubMed

Aaboud, M; Aad, G; Abbott, B; Abdallah, J; Abdinov, O; Abeloos, B; AbouZeid, O S; Abraham, N L; Abramowicz, H; Abreu, H; Abreu, R; Abulaiti, Y; Acharya, B S; Adachi, S; Adamczyk, L; Adams, D L; Adelman, J; Adomeit, S; Adye, T; Affolder, A A; Agatonovic-Jovin, T; Aguilar-Saavedra, J A; Ahlen, S P; Ahmadov, F; Aielli, G; Akerstedt, H; Åkesson, T P A; Akimov, A V; Alberghi, G L; Albert, J; Albrand, S; Alconada Verzini, M J; Aleksa, M; Aleksandrov, I N; Alexa, C; Alexander, G; Alexopoulos, T; Alhroob, M; Ali, B; Aliev, M; Alimonti, G; Alison, J; Alkire, S P; Allbrooke, B M M; Allen, B W; Allport, P P; Aloisio, A; Alonso, A; Alonso, F; Alpigiani, C; Alshehri, A A; Alstaty, M; Gonzalez, B Alvarez; Piqueras, D Álvarez; Alviggi, M G; Amadio, B T; Amaral Coutinho, Y; Amelung, C; Amidei, D; Amor Dos Santos, S P; Amorim, A; Amoroso, S; Amundsen, G; Anastopoulos, C; Ancu, L S; Andari, N; Andeen, T; Anders, C F; Anders, J K; Anderson, K J; Andreazza, A; Andrei, V; Angelidakis, S; Angelozzi, I; Angerami, A; Anghinolfi, F; Anisenkov, A V; Anjos, N; Annovi, A; Antel, C; Antonelli, M; Antonov, A; Antrim, D J; Anulli, F; Aoki, M; Aperio Bella, L; Arabidze, G; Arai, Y; Araque, J P; Arce, A T H; Arduh, F A; Arguin, J-F; Argyropoulos, S; Arik, M; Armbruster, A J; Armitage, L J; Arnaez, O; Arnold, H; Arratia, M; Arslan, O; Artamonov, A; Artoni, G; Artz, S; Asai, S; Asbah, N; Ashkenazi, A; Åsman, B; Asquith, L; Assamagan, K; Astalos, R; Atkinson, M; Atlay, N B; Augsten, K; Avolio, G; Axen, B; Ayoub, M K; Azuelos, G; Baak, M A; Baas, A E; Baca, M J; Bachacou, H; Bachas, K; Backes, M; Backhaus, M; Bagiacchi, P; Bagnaia, P; Bai, Y; Baines, J T; Bajic, M; Baker, O K; Baldin, E M; Balek, P; Balestri, T; Balli, F; Balunas, W K; Banas, E; Banerjee, Sw; Bannoura, A A E; Barak, L; Barberio, E L; Barberis, D; Barbero, M; Barillari, T; Barisits, M-S; Barklow, T; Barlow, N; Barnes, S L; Barnett, B M; Barnett, R M; Barnovska-Blenessy, Z; Baroncelli, A; Barone, G; Barr, A J; Barranco Navarro, L; Barreiro, F; Barreiro Guimarães da Costa, J; Bartoldus, R; Barton, A E; Bartos, P; Basalaev, A; Bassalat, A; Bates, R L; Batista, S J; Batley, J R; Battaglia, M; Bauce, M; Bauer, F; Bawa, H S; Beacham, J B; Beattie, M D; Beau, T; Beauchemin, P H; Bechtle, P; Beck, H P; Becker, K; Becker, M; Beckingham, M; Becot, C; Beddall, A J; Beddall, A; Bednyakov, V A; Bedognetti, M; Bee, C P; Beemster, L J; Beermann, T A; Begel, M; Behr, J K; Bell, A S; Bella, G; Bellagamba, L; Bellerive, A; Bellomo, M; Belotskiy, K; Beltramello, O; Belyaev, N L; Benary, O; Benchekroun, D; Bender, M; Bendtz, K; Benekos, N; Benhammou, Y; Benhar Noccioli, E; Benitez, J; Benjamin, D P; Bensinger, J R; Bentvelsen, S; Beresford, L; Beretta, M; Berge, D; Bergeaas Kuutmann, E; Berger, N; Beringer, J; Berlendis, S; Bernard, N R; Bernius, C; Bernlochner, F U; Berry, T; Berta, P; Bertella, C; Bertoli, G; Bertolucci, F; Bertram, I A; Bertsche, C; Bertsche, D; Besjes, G J; Bessidskaia Bylund, O; Bessner, M; Besson, N; Betancourt, C; Bethani, A; Bethke, S; Bevan, A J; Bianchi, R M; Bianco, M; Biebel, O; Biedermann, D; Bielski, R; Biesuz, N V; Biglietti, M; Bilbao De Mendizabal, J; Billoud, T R V; Bilokon, H; Bindi, M; Bingul, A; Bini, C; Biondi, S; Bisanz, T; Bjergaard, D M; Black, C W; Black, J E; Black, K M; Blackburn, D; Blair, R E; Blazek, T; Bloch, I; Blocker, C; Blue, A; Blum, W; Blumenschein, U; Blunier, S; Bobbink, G J; Bobrovnikov, V S; Bocchetta, S S; Bocci, A; Bock, C; Boehler, M; Boerner, D; Bogaerts, J A; Bogavac, D; Bogdanchikov, A G; Bohm, C; Boisvert, V; Bokan, P; Bold, T; Boldyrev, A S; Bomben, M; Bona, M; Boonekamp, M; Borisov, A; Borissov, G; Bortfeldt, J; Bortoletto, D; Bortolotto, V; Bos, K; Boscherini, D; Bosman, M; Bossio Sola, J D; Boudreau, J; Bouffard, J; Bouhova-Thacker, E V; Boumediene, D; Bourdarios, C; Boutle, S K; Boveia, A; Boyd, J; Boyko, I R; Bracinik, J; Brandt, A; Brandt, G; Brandt, O; Bratzler, U; Brau, B; Brau, J E; Breaden Madden, W D; Brendlinger, K; Brennan, A J; Brenner, L; Brenner, R; Bressler, S; Bristow, T M; Britton, D; Britzger, D; Brochu, F M; Brock, I; Brock, R; Brooijmans, G; Brooks, T; Brooks, W K; Brosamer, J; Brost, E; Broughton, J H; Bruckman de Renstrom, P A; Bruncko, D; Bruneliere, R; Bruni, A; Bruni, G; Bruni, L S; Brunt, B H; Bruschi, M; Bruscino, N; Bryant, P; Bryngemark, L; Buanes, T; Buat, Q; Buchholz, P; Buckley, A G; Budagov, I A; Buehrer, F; Bugge, M K; Bulekov, O; Bullock, D; Burckhart, H; Burdin, S; Burgard, C D; Burger, A M; Burghgrave, B; Burka, K; Burke, S; Burmeister, I; Burr, J T P; Busato, E; Büscher, D; Büscher, V; Bussey, P; Butler, J M; Buttar, C M; Butterworth, J M; Butti, P; Buttinger, W; Buzatu, A; Buzykaev, A R; Cabrera Urbán, S; Caforio, D; Cairo, V M; Cakir, O; Calace, N; Calafiura, P; Calandri, A; Calderini, G; Calfayan, P; Callea, G; Caloba, L P; Calvente Lopez, S; Calvet, D; Calvet, S; Calvet, T P; Camacho Toro, R; Camarda, S; Camarri, P; Cameron, D; Caminal Armadans, R; Camincher, C; Campana, S; Campanelli, M; Camplani, A; Campoverde, A; Canale, V; Canepa, A; Cano Bret, M; Cantero, J; Cao, T; Capeans Garrido, M D M; Caprini, I; Caprini, M; Capua, M; Carbone, R M; Cardarelli, R; Cardillo, F; Carli, I; Carli, T; Carlino, G; Carlson, B T; Carminati, L; Carney, R M D; Caron, S; Carquin, E; Carrillo-Montoya, G D; Carter, J R; Carvalho, J; Casadei, D; Casado, M P; Casolino, M; Casper, D W; Castaneda-Miranda, E; Castelijn, R; Castelli, A; Castillo Gimenez, V; Castro, N F; Catinaccio, A; Catmore, J R; Cattai, A; Caudron, J; Cavaliere, V; Cavallaro, E; Cavalli, D; Cavalli-Sforza, M; Cavasinni, V; Ceradini, F; Cerda Alberich, L; Cerqueira, A S; Cerri, A; Cerrito, L; Cerutti, F; Cervelli, A; Cetin, S A; Chafaq, A; Chakraborty, D; Chan, S K; Chan, Y L; Chang, P; Chapman, J D; Charlton, D G; Chatterjee, A; Chau, C C; Chavez Barajas, C A; Che, S; Cheatham, S; Chegwidden, A; Chekanov, S; Chekulaev, S V; Chelkov, G A; Chelstowska, M A; Chen, C; Chen, H; Chen, S; Chen, S; Chen, X; Chen, Y; Cheng, H C; Cheng, H J; Cheng, Y; Cheplakov, A; Cheremushkina, E; Cherkaoui El Moursli, R; Chernyatin, V; Cheu, E; Chevalier, L; Chiarella, V; Chiarelli, G; Chiodini, G; Chisholm, A S; Chitan, A; Chizhov, M V; Choi, K; Chomont, A R; Chouridou, S; Chow, B K B; Christodoulou, V; Chromek-Burckhart, D; Chudoba, J; Chuinard, A J; Chwastowski, J J; Chytka, L; Ciapetti, G; Ciftci, A K; Cinca, D; Cindro, V; Cioara, I A; Ciocca, C; Ciocio, A; Cirotto, F; Citron, Z H; Citterio, M; Ciubancan, M; Clark, A; Clark, B L; Clark, M R; Clark, P J; Clarke, R N; Clement, C; Coadou, Y; Cobal, M; Coccaro, A; Cochran, J; Colasurdo, L; Cole, B; Colijn, A P; Collot, J; Colombo, T; Conde Muiño, P; Coniavitis, E; Connell, S H; Connelly, I A; Consorti, V; Constantinescu, S; Conti, G; Conventi, F; Cooke, M; Cooper, B D; Cooper-Sarkar, A M; Cormier, F; Cormier, K J R; Cornelissen, T; Corradi, M; Corriveau, F; Cortes-Gonzalez, A; Cortiana, G; Costa, G; Costa, M J; Costanzo, D; Cottin, G; Cowan, G; Cox, B E; Cranmer, K; Crawley, S J; Cree, G; Crépé-Renaudin, S; Crescioli, F; Cribbs, W A; Crispin Ortuzar, M; Cristinziani, M; Croft, V; Crosetti, G; Cueto, A; Cuhadar Donszelmann, T; Cummings, J; Curatolo, M; Cúth, J; Czirr, H; Czodrowski, P; D'amen, G; D'Auria, S; D'Onofrio, M; Da Cunha Sargedas De Sousa, M J; Da Via, C; Dabrowski, W; Dado, T; Dai, T; Dale, O; Dallaire, F; Dallapiccola, C; Dam, M; Dandoy, J R; Dang, N P; Daniells, A C; Dann, N S; Danninger, M; Dano Hoffmann, M; Dao, V; Darbo, G; Darmora, S; Dassoulas, J; Dattagupta, A; Davey, W; David, C; Davidek, T; Davies, M; Davison, P; Dawe, E; Dawson, I; De, K; de Asmundis, R; De Benedetti, A; De Castro, S; De Cecco, S; De Groot, N; de Jong, P; De la Torre, H; De Lorenzi, F; De Maria, A; De Pedis, D; De Salvo, A; De Sanctis, U; De Santo, A; De Vivie De Regie, J B; Dearnaley, W J; Debbe, R; Debenedetti, C; Dedovich, D V; Dehghanian, N; Deigaard, I; Del Gaudio, M; Del Peso, J; Del Prete, T; Delgove, D; Deliot, F; Delitzsch, C M; Dell'Acqua, A; Dell'Asta, L; Dell'Orso, M; Della Pietra, M; Della Volpe, D; Delmastro, M; Delsart, P A; DeMarco, D A; Demers, S; Demichev, M; Demilly, A; Denisov, S P; Denysiuk, D; Derendarz, D; Derkaoui, J E; Derue, F; Dervan, P; Desch, K; Deterre, C; Dette, K; Deviveiros, P O; Dewhurst, A; Dhaliwal, S; Di Ciaccio, A; Di Ciaccio, L; Di Clemente, W K; Di Donato, C; Di Girolamo, A; Di Girolamo, B; Di Micco, B; Di Nardo, R; Di Petrillo, K F; Di Simone, A; Di Sipio, R; Di Valentino, D; Diaconu, C; Diamond, M; Dias, F A; Diaz, M A; Diehl, E B; Dietrich, J; Díez Cornell, S; Dimitrievska, A; Dingfelder, J; Dita, P; Dita, S; Dittus, F; Djama, F; Djobava, T; Djuvsland, J I; do Vale, M A B; Dobos, D; Dobre, M; Doglioni, C; Dolejsi, J; Dolezal, Z; Donadelli, M; Donati, S; Dondero, P; Donini, J; Dopke, J; Doria, A; Dova, M T; Doyle, A T; Drechsler, E; Dris, M; Du, Y; Duarte-Campderros, J; Duchovni, E; Duckeck, G; Ducu, O A; Duda, D; Dudarev, A; Dudder, A Chr; Duffield, E M; Duflot, L; Dührssen, M; Dumancic, M; Duncan, A K; Dunford, M; Duran Yildiz, H; Düren, M; Durglishvili, A; Duschinger, D; Dutta, B; Dyndal, M; 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Reed, R G; Reeves, K; Rehnisch, L; Reichert, J; Reiss, A; Rembser, C; Ren, H; Rescigno, M; Resconi, S; Rezanova, O L; Reznicek, P; Rezvani, R; Richter, R; Richter, S; Richter-Was, E; Ricken, O; Ridel, M; Rieck, P; Riegel, C J; Rieger, J; Rifki, O; Rijssenbeek, M; Rimoldi, A; Rimoldi, M; Rinaldi, L; Ristić, B; Ritsch, E; Riu, I; Rizatdinova, F; Rizvi, E; Rizzi, C; Roberts, R T; Robertson, S H; Robichaud-Veronneau, A; Robinson, D; Robinson, J E M; Robson, A; Roda, C; Rodina, Y; Rodriguez Perez, A; Rodriguez Rodriguez, D; Roe, S; Rogan, C S; Røhne, O; Roloff, J; Romaniouk, A; Romano, M; Romano Saez, S M; Romero Adam, E; Rompotis, N; Ronzani, M; Roos, L; Ros, E; Rosati, S; Rosbach, K; Rose, P; Rosien, N-A; Rossetti, V; Rossi, E; Rossi, L P; Rosten, J H N; Rosten, R; Rotaru, M; Roth, I; Rothberg, J; Rousseau, D; Rozanov, A; Rozen, Y; Ruan, X; Rubbo, F; Rudolph, M S; Rühr, F; Ruiz-Martinez, A; Rurikova, Z; Rusakovich, N A; Ruschke, A; Russell, H L; Rutherfoord, J P; Ruthmann, N; Ryabov, Y F; Rybar, M; Rybkin, G; Ryu, S; Ryzhov, A; Rzehorz, G F; Saavedra, A F; Sabato, G; Sacerdoti, S; Sadrozinski, H F-W; Sadykov, R; Safai Tehrani, F; Saha, P; Sahinsoy, M; Saimpert, M; Saito, T; Sakamoto, H; Sakurai, Y; Salamanna, G; Salamon, A; Salazar Loyola, J E; Salek, D; Sales De Bruin, P H; Salihagic, D; Salnikov, A; Salt, J; Salvatore, D; Salvatore, F; Salvucci, A; Salzburger, A; Sammel, D; Sampsonidis, D; Sánchez, J; Sanchez Martinez, V; Sanchez Pineda, A; Sandaker, H; Sandbach, R L; Sandhoff, M; Sandoval, C; Sankey, D P C; Sannino, M; Sansoni, A; Santoni, C; Santonico, R; Santos, H; Santoyo Castillo, I; Sapp, K; Sapronov, A; Saraiva, J G; Sarrazin, B; Sasaki, O; Sato, K; Sauvan, E; Savage, G; Savard, P; Savic, N; Sawyer, C; Sawyer, L; Saxon, J; Sbarra, C; Sbrizzi, A; Scanlon, T; Scannicchio, D A; Scarcella, M; Scarfone, V; Schaarschmidt, J; Schacht, P; Schachtner, B M; Schaefer, D; Schaefer, L; Schaefer, R; Schaeffer, J; Schaepe, S; Schaetzel, S; Schäfer, U; Schaffer, A C; Schaile, D; Schamberger, R D; Scharf, V; Schegelsky, V A; Scheirich, D; Schernau, M; Schiavi, C; Schier, S; Schillo, C; Schioppa, M; Schlenker, S; Schmidt-Sommerfeld, K R; Schmieden, K; Schmitt, C; Schmitt, S; Schmitz, S; Schneider, B; Schnoor, U; Schoeffel, L; Schoening, A; Schoenrock, B D; Schopf, E; Schott, M; Schouwenberg, J F P; Schovancova, J; Schramm, S; Schreyer, M; Schuh, N; Schulte, A; Schultens, M J; Schultz-Coulon, H-C; Schulz, H; Schumacher, M; Schumm, B A; Schune, Ph; Schwartzman, A; Schwarz, T A; Schweiger, H; Schwemling, Ph; Schwienhorst, R; Schwindling, J; Schwindt, T; Sciolla, G; Scuri, F; Scutti, F; Searcy, J; Seema, P; Seidel, S C; Seiden, A; Seifert, F; Seixas, J M; Sekhniaidze, G; Sekhon, K; Sekula, S J; Seliverstov, D M; Semprini-Cesari, N; Serfon, C; Serin, L; Serkin, L; Sessa, M; Seuster, R; Severini, H; Sfiligoj, T; Sforza, F; Sfyrla, A; Shabalina, E; Shaikh, N W; Shan, L Y; Shang, R; Shank, J T; Shapiro, M; Shatalov, P B; Shaw, K; Shaw, S M; Shcherbakova, A; Shehu, C Y; Sherwood, P; Shi, L; Shimizu, S; Shimmin, C O; Shimojima, M; Shirabe, S; Shiyakova, M; Shmeleva, A; Shoaleh Saadi, D; Shochet, M J; Shojaii, S; Shope, D R; Shrestha, S; Shulga, E; Shupe, M A; Sicho, P; Sickles, A M; Sidebo, P E; Sideras Haddad, E; Sidiropoulou, O; Sidorov, D; Sidoti, A; Siegert, F; Sijacki, Dj; Silva, J; Silverstein, S B; Simak, V; Simic, Lj; Simion, S; Simioni, E; Simmons, B; Simon, D; Simon, M; Sinervo, P; Sinev, N B; Sioli, M; Siragusa, G; Siral, I; Sivoklokov, S Yu; Sjölin, J; Skinner, M B; Skottowe, H P; Skubic, P; Slater, M; Slavicek, T; Slawinska, M; Sliwa, K; Slovak, R; Smakhtin, V; Smart, B H; Smestad, L; Smiesko, J; Smirnov, S Yu; Smirnov, Y; Smirnova, L N; Smirnova, O; Smith, J W; Smith, M N K; Smith, R W; Smizanska, M; Smolek, K; Snesarev, A A; Snyder, I M; Snyder, S; Sobie, R; Socher, F; Soffer, A; Soh, D A; Sokhrannyi, G; Solans Sanchez, C A; Solar, M; Soldatov, E Yu; Soldevila, U; Solodkov, A A; Soloshenko, A; Solovyanov, O V; Solovyev, V; Sommer, P; Son, H; Song, H Y; Sood, A; Sopczak, A; Sopko, V; Sorin, V; Sosa, D; Sotiropoulou, C L; Soualah, R; Soukharev, A M; South, D; Sowden, B C; Spagnolo, S; Spalla, M; Spangenberg, M; Spanò, F; Sperlich, D; Spettel, F; Spighi, R; Spigo, G; Spiller, L A; Spousta, M; St Denis, R D; Stabile, A; Stamen, R; Stamm, S; Stanecka, E; Stanek, R W; Stanescu, C; Stanescu-Bellu, M; Stanitzki, M M; Stapnes, S; Starchenko, E A; Stark, G H; Stark, J; Staroba, P; Starovoitov, P; Stärz, S; Staszewski, R; Steinberg, P; Stelzer, B; Stelzer, H J; Stelzer-Chilton, O; Stenzel, H; Stewart, G A; Stillings, J A; Stockton, M C; Stoebe, M; Stoicea, G; Stolte, P; Stonjek, S; Stradling, A R; Straessner, A; Stramaglia, M E; Strandberg, J; Strandberg, S; Strandlie, A; Strauss, M; Strizenec, P; Ströhmer, R; Strom, D M; Stroynowski, R; Strubig, A; Stucci, S A; Stugu, B; Styles, N A; Su, D; Su, J; Suchek, S; Sugaya, Y; Suk, M; Sulin, V V; Sultansoy, S; Sumida, T; Sun, S; Sun, X; Sundermann, J E; Suruliz, K; Suster, C J E; Sutton, M R; Suzuki, S; Svatos, M; Swiatlowski, M; Swift, S P; Sykora, I; Sykora, T; Ta, D; Tackmann, K; Taenzer, J; Taffard, A; Tafirout, R; Taiblum, N; Takai, H; Takashima, R; Takeshita, T; Takubo, Y; Talby, M; Talyshev, A A; Tanaka, J; Tanaka, M; Tanaka, R; Tanaka, S; Tanioka, R; Tannenwald, B B; Tapia Araya, S; Tapprogge, S; Tarem, S; Tartarelli, G F; Tas, P; Tasevsky, M; Tashiro, T; Tassi, E; Tavares Delgado, A; Tayalati, Y; Taylor, A C; Taylor, G N; Taylor, P T E; Taylor, W; Teischinger, F A; Teixeira-Dias, P; Temming, K K; Temple, D; Ten Kate, H; Teng, P K; Teoh, J J; Tepel, F; Terada, S; Terashi, K; Terron, J; Terzo, S; Testa, M; Teuscher, R J; Theveneaux-Pelzer, T; Thomas, J P; Thomas-Wilsker, J; Thompson, P D; Thompson, A S; Thomsen, L A; Thomson, E; Tibbetts, M J; Ticse Torres, R E; Tikhomirov, V O; Tikhonov, Yu A; Timoshenko, S; Tipton, P; Tisserant, S; Todome, K; Todorov, T; Todorova-Nova, S; Tojo, J; Tokár, S; Tokushuku, K; Tolley, E; Tomlinson, L; Tomoto, M; Tompkins, L; Toms, K; Tong, B; Tornambe, P; Torrence, E; Torres, H; Torró Pastor, E; Toth, J; Touchard, F; Tovey, D R; Trefzger, T; Tricoli, A; Trigger, I M; Trincaz-Duvoid, S; Tripiana, M F; Trischuk, W; Trocmé, B; Trofymov, A; Troncon, C; Trottier-McDonald, M; Trovatelli, M; Truong, L; Trzebinski, M; Trzupek, A; Tseng, J C-L; Tsiareshka, P V; Tsipolitis, G; Tsirintanis, N; Tsiskaridze, S; Tsiskaridze, V; Tskhadadze, E G; Tsui, K M; Tsukerman, I I; Tsulaia, V; Tsuno, S; Tsybychev, D; Tu, Y; Tudorache, A; Tudorache, V; Tulbure, T T; Tuna, A N; Tupputi, S A; Turchikhin, S; Turgeman, D; Turk Cakir, I; Turra, R; Tuts, P M; Ucchielli, G; Ueda, I; Ughetto, M; Ukegawa, F; Unal, G; Undrus, A; Unel, G; Ungaro, F C; Unno, Y; Unverdorben, C; Urban, J; Urquijo, P; Urrejola, P; Usai, G; Usui, J; Vacavant, L; Vacek, V; Vachon, B; Valderanis, C; Valdes Santurio, E; Valencic, N; Valentinetti, S; Valero, A; Valery, L; Valkar, S; Ferrer, J A Valls; Van Den Wollenberg, W; Van Der Deijl, P C; van der Graaf, H; van Eldik, N; van Gemmeren, P; Van Nieuwkoop, J; van Vulpen, I; van Woerden, M C; Vanadia, M; Vandelli, W; Vanguri, R; Vaniachine, A; Vankov, P; Vardanyan, G; Vari, R; Varnes, E W; Varol, T; Varouchas, D; Vartapetian, A; Varvell, K E; Vasquez, J G; Vasquez, G A; Vazeille, F; Schroeder, T Vazquez; Veatch, J; Veeraraghavan, V; Veloce, L M; Veloso, F; Veneziano, S; Ventura, A; Venturi, M; Venturi, N; Venturini, A; Vercesi, V; Verducci, M; Verkerke, W; Vermeulen, J C; Vest, A; Vetterli, M C; Viazlo, O; Vichou, I; Vickey, T; Boeriu, O E Vickey; Viehhauser, G H A; Viel, S; Vigani, L; Villa, M; Perez, M Villaplana; Vilucchi, E; Vincter, M G; Vinogradov, V B; Vittori, C; Vivarelli, I; Vlachos, S; Vlasak, M; Vogel, M; Vokac, P; Volpi, G; Volpi, M; von der Schmitt, H; von Toerne, E; Vorobel, V; Vorobev, K; Vos, M; Voss, R; Vossebeld, J H; Vranjes, N; Milosavljevic, M Vranjes; Vrba, V; Vreeswijk, M; Vuillermet, R; Vukotic, I; Wagner, P; Wagner, W; Wahlberg, H; Wahrmund, S; Wakabayashi, J; Walder, J; Walker, R; Walkowiak, W; Wallangen, V; 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Živković, L; Zobernig, G; Zoccoli, A; Nedden, M Zur; Zwalinski, L

2017-01-01

Measurements of jet activity in top-quark pair events produced in proton-proton collisions are presented, using 3.2 fb[Formula: see text] of pp collision data at a centre-of-mass energy of 13 TeV collected by the ATLAS experiment at the Large Hadron Collider. Events are chosen by requiring an opposite-charge [Formula: see text] pair and two b -tagged jets in the final state. The normalised differential cross-sections of top-quark pair production are presented as functions of additional-jet multiplicity and transverse momentum, [Formula: see text]. The fraction of signal events that do not contain additional jet activity in a given rapidity region, the gap fraction, is measured as a function of the [Formula: see text] threshold for additional jets, and is also presented for different invariant mass regions of the [Formula: see text] system. All measurements are corrected for detector effects and presented as particle-level distributions compared to predictions with different theoretical approaches for QCD radiation. While the kinematics of the jets from top-quark decays are described well, the generators show differing levels of agreement with the measurements of observables that depend on the production of additional jets.

Measurement of jet activity produced in top-quark events with an electron, a muon and two b-tagged jets in the final state in pp collisions at √s = 13 TeV with the ATLAS detector

DOE PAGES

Aaboud, M; Aad, G; Abbott, B; ...

2017-04-07

Measurements of jet activity in top-quark pair events produced in proton–proton collisions are presented, using 3.2 fb –1 of pp collision data at a centre-of-mass energy of 13 TeV collected by the ATLAS experiment at the Large Hadron Collider. Events are chosen by requiring an opposite-charge eμ pair and two b-tagged jets in the final state. The normalised differential cross-sections of top-quark pair production are presented as functions of additional-jet multiplicity and transverse momentum, p T. The fraction of signal events that do not contain additional jet activity in a given rapidity region, the gap fraction, is measured as amore » function of the p T threshold for additional jets, and is also presented for different invariant mass regions of the eμbb¯ system. All measurements are corrected for detector effects and presented as particle-level distributions compared to predictions with different theoretical approaches for QCD radiation. While the kinematics of the jets from top-quark decays are described well, the generators show differing levels of agreement with the measurements of observables that depend on the production of additional jets.« less

Measurement of jet activity produced in top-quark events with an electron, a muon and two b-tagged jets in the final state in pp collisions at √s = 13 TeV with the ATLAS detector

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aaboud, M; Aad, G; Abbott, B

Measurements of jet activity in top-quark pair events produced in proton–proton collisions are presented, using 3.2 fb –1 of pp collision data at a centre-of-mass energy of 13 TeV collected by the ATLAS experiment at the Large Hadron Collider. Events are chosen by requiring an opposite-charge eμ pair and two b-tagged jets in the final state. The normalised differential cross-sections of top-quark pair production are presented as functions of additional-jet multiplicity and transverse momentum, p T. The fraction of signal events that do not contain additional jet activity in a given rapidity region, the gap fraction, is measured as amore » function of the p T threshold for additional jets, and is also presented for different invariant mass regions of the eμbb¯ system. All measurements are corrected for detector effects and presented as particle-level distributions compared to predictions with different theoretical approaches for QCD radiation. While the kinematics of the jets from top-quark decays are described well, the generators show differing levels of agreement with the measurements of observables that depend on the production of additional jets.« less

78 FR 5813 - 2013 Assuring Radiation Protection

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-28

...] 2013 Assuring Radiation Protection AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY... of the Center for Devices and Radiological Health (CDRH) radiation protection program. The goal of the 2013 Assuring Radiation Protection will be to coordinate Federal, State, and Tribal activities to...

On the Generation of Intermediate Number Squeezed State of the Quantized Radiation Field

NASA Astrophysics Data System (ADS)

Baseia, B.; de Lima, A. F.; Bagnato, V. S.

Recently, a new state of the quantized radiation field — the intermediate number squeezed state (INSS) — has been introduced in the literature: it interpolates between the number state |n> and the squeezed state |z, α>=Ŝ(z)|α>, and exhibits interesting nonclassical properties as antibunching, sub-Poissonian statistics and squeezing. Here we introduce a slight modification in the previous definition allowing us a proposal to generate the INSS. Nonclassical properties using a new set of parameters are also studied.

High-Density Signal Interface Electromagnetic Radiation Prediction for Electromagnetic Compatibility Evaluation.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Halligan, Matthew

Radiated power calculation approaches for practical scenarios of incomplete high- density interface characterization information and incomplete incident power information are presented. The suggested approaches build upon a method that characterizes power losses through the definition of power loss constant matrices. Potential radiated power estimates include using total power loss information, partial radiated power loss information, worst case analysis, and statistical bounding analysis. A method is also proposed to calculate radiated power when incident power information is not fully known for non-periodic signals at the interface. Incident data signals are modeled from a two-state Markov chain where bit state probabilities aremore » derived. The total spectrum for windowed signals is postulated as the superposition of spectra from individual pulses in a data sequence. Statistical bounding methods are proposed as a basis for the radiated power calculation due to the statistical calculation complexity to find a radiated power probability density function.« less

Radiation Injury to the Brain

MedlinePlus

... healthy cells. The Merck Manual states the following: Radiation Injury to the Nervous System: The nervous system can be damaged by radiation therapy. Acute and subacute transient symptoms may develop early, but ...

10 CFR 72.54 - Expiration and termination of licenses and decommissioning of sites and separate buildings or...

Code of Federal Regulations, 2010 CFR

2010-01-01

... conduct of decommissioning operations and presents no undue risk from radiation to the public health and... final radiation survey; and (5) An updated detailed cost estimate for the chosen alternative for... accordance with the regulations in this chapter, and will not be inimical to the common defense and security...

Preliminary test Results for a 25K Sorption Cryocooler Designed for the UCSB Long Duration Balloon Cosmic Microwave Background Radiation Experiment

NASA Technical Reports Server (NTRS)

Wade, L. A.; Levy, A. R.

1996-01-01

A continuous operation, vibration-free, long-life 25K sorption cryocooler has been built and is now in final integration and performance testing. This cooler wil be flown on the University of California at Santa Barbara (UCSB) Long Duration Balloon (LDB) Cosmic Microwave Background Radiation Experiment.

Recent advances in radiation oncology.

PubMed

Garibaldi, Cristina; Jereczek-Fossa, Barbara Alicja; Marvaso, Giulia; Dicuonzo, Samantha; Rojas, Damaris Patricia; Cattani, Federica; Starzyńska, Anna; Ciardo, Delia; Surgo, Alessia; Leonardi, Maria Cristina; Ricotti, Rosalinda

2017-01-01

Radiotherapy (RT) is very much a technology-driven treatment modality in the management of cancer. RT techniques have changed significantly over the past few decades, thanks to improvements in engineering and computing. We aim to highlight the recent developments in radiation oncology, focusing on the technological and biological advances. We will present state-of-the-art treatment techniques, employing photon beams, such as intensity-modulated RT, volumetric-modulated arc therapy, stereotactic body RT and adaptive RT, which make possible a highly tailored dose distribution with maximum normal tissue sparing. We will analyse all the steps involved in the treatment: imaging, delineation of the tumour and organs at risk, treatment planning and finally image-guidance for accurate tumour localisation before and during treatment delivery. Particular attention will be given to the crucial role that imaging plays throughout the entire process. In the case of adaptive RT, the precise identification of target volumes as well as the monitoring of tumour response/modification during the course of treatment is mainly based on multimodality imaging that integrates morphological, functional and metabolic information. Moreover, real-time imaging of the tumour is essential in breathing adaptive techniques to compensate for tumour motion due to respiration. Brief reference will be made to the recent spread of particle beam therapy, in particular to the use of protons, but also to the yet limited experience of using heavy particles such as carbon ions. Finally, we will analyse the latest biological advances in tumour targeting. Indeed, the effectiveness of RT has been improved not only by technological developments but also through the integration of radiobiological knowledge to produce more efficient and personalised treatment strategies.

A History of the International Commission on Non-Ionizing Radiation Protection.

PubMed

Repacholi, M H

2017-10-01

Concern about health risks from exposure to non-ionizing radiation (NIR) commenced in the 1950s after tracking radars were first introduced during the Second World War. Soon after, research on possible biological effects of microwave radiation in the former Soviet Union and the U.S. led to public and worker exposure limits being much lower in Eastern European than in Western countries, mainly because of different protection philosophies. As public concern increased, national authorities began introducing legislation to limit NIR exposures from domestic microwave ovens and workplace devices such as visual display units. The International Radiation Protection Association (IRPA) was formed in 1966 to represent national radiation protection societies. To address NIR protection issues, IRPA established a Working Group in 1974, then a Study Group in 1975, and finally the International NIR Committee (INIRC) in 1977. INIRC's publications quickly became accepted worldwide, and it was logical that it should become an independent commission. IRPA finally established the International Commission on Non-Ionizing Radiation Protection (ICNIRP), chartering its remit in 1992, and defining NIR as electromagnetic radiation (ultraviolet, visible, infrared), electromagnetic waves and fields, and infra- and ultrasound. ICNIRP's guidelines have been incorporated into legislation or adopted as standards in many countries. While ICNIRP has been subjected to criticism and close scrutiny by the public, media, and activists, it has continued to issue well-received, independent, science-based protection advice. This paper summarizes events leading to the formation of ICNIRP, its key activities up to 2017, ICNIRP's 25th anniversary year, and its future challenges.

PROTOSTELLAR OUTFLOWS AND RADIATIVE FEEDBACK FROM MASSIVE STARS. II. FEEDBACK, STAR-FORMATION EFFICIENCY, AND OUTFLOW BROADENING

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuiper, Rolf; Turner, Neal J.; Yorke, Harold W., E-mail: rolf.kuiper@uni-tuebingen.de, E-mail: Neal.J.Turner@jpl.nasa.gov, E-mail: Harold.W.Yorke@jpl.nasa.gov

2016-11-20

We perform two-dimensional axially symmetric radiation hydrodynamic simulations to assess the impact of outflows and radiative force feedback from massive protostars by varying when the protostellar outflow starts, and to determine the ratio of ejection to accretion rates and the strength of the wide-angle disk wind component. The star-formation efficiency, i.e., the ratio of final stellar mass to initial core mass, is dominated by radiative forces and the ratio of outflow to accretion rates. Increasing this ratio has three effects. First, the protostar grows slower with a lower luminosity at any given time, lowering radiative feedback. Second, bipolar cavities clearedmore » by the outflow become larger, further diminishing radiative feedback on disk and core scales. Third, the higher momentum outflow sweeps up more material from the collapsing envelope, decreasing the protostar's potential mass reservoir via entrainment. The star-formation efficiency varies with the ratio of ejection to accretion rates from 50% in the case of very weak outflows to as low as 20% for very strong outflows. At latitudes between the low-density bipolar cavity and the high-density accretion disk, wide-angle disk winds remove some of the gas, which otherwise would be part of the accretion flow onto the disk; varying the strength of these wide-angle disk winds, however, alters the final star-formation efficiency by only ±6%. For all cases, the opening angle of the bipolar outflow cavity remains below 20° during early protostellar accretion phases, increasing rapidly up to 65° at the onset of radiation pressure feedback.« less

Charge-exchange x-ray spectra: Evidence for significant contributions from radiative decays of doubly excited states

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ali, R.; Beiersdorfer, P.; Harris, C. L.

2016-01-21

Charge-exchange collisions of slow Ne 10+ ions with He, Ne, and Ar targets were studied with simultaneous x-ray and cold-target recoil-ion-momentum spectroscopy proving the contribution of several mechanisms to the radiative stabilization of apparent (4,4) doubly excited states for He and Ne targets and of (5,6) states for Ar. In particular, the stabilization efficiency of the mechanism of dynamic auto-transfer to Rydberg states is confirmed. Moreover, we present evidence for direct radiative decays of (4,4) states populated in collisions with He, which is an experimental indication of the population of so-called unnatural-parity states in such collisions. Lastly, these mechanisms leadmore » to the emission of x-rays that have considerably higher energies than those predicted by current spectral models and may explain recent observations of anomalously large x-ray emission from Rydberg levels.« less

Constraining the compressed spectrum of the top squark and chargino along the W corridor

NASA Astrophysics Data System (ADS)

Cheng, Hsin-Chia; Li, Lingfeng; Qin, Qin

2018-03-01

Studying superpartner production together with a hard initial state radiation jet has been a useful strategy for searches of supersymmetry with a compressed spectrum at the LHC. In the case of the top squark (stop), the ratio of the missing transverse momentum from the lightest neutralinos and the initial state radiation momentum, defined as R¯M, turns out to be an effective variable to distinguish the signal from the backgrounds. It has helped to exclude the stop mass below 590 GeV along the top corridor where mt ˜-mχ˜1 0≈mt . On the other hand, the current experimental limit is still rather weak in the W corridor where mt ˜-mχ˜10≈mW+mb. In this work, we extend this strategy to the parameter region around the W corridor by considering the one lepton final state. In this case, the kinematic constraints are insufficient to completely determine the neutrino momentum, which is required to calculate R¯M. However, the minimum value of R¯M consistent with the kinematic constraints still provides a useful discriminating variable, allowing the exclusion reach of the stop mass to be extended to ˜550 GeV based on the current 36 fb-1 LHC data. The same method can also be applied to the chargino search with mχ˜1±-mχ˜10≈mW because the analysis does not rely on b jets. If no excess is present in the current data, a chargino mass of 300 GeV along the W corridor can be excluded, beyond the limit obtained from the multilepton search.

PANDORA, a new facility for interdisciplinary in-plasma physics

NASA Astrophysics Data System (ADS)

Mascali, D.; Musumarra, A.; Leone, F.; Romano, F. P.; Galatà, A.; Gammino, S.; Massimi, C.

2017-07-01

PANDORA, Plasmas for Astrophysics, Nuclear Decays Observation and Radiation for Archaeometry, is planned as a new facility based on a state-of-the-art plasma trap confining energetic plasma for performing interdisciplinary research in the fields of Nuclear Astrophysics, Astrophysics, Plasma Physics and Applications in Material Science and Archaeometry: the plasmas become the environment for measuring, for the first time, nuclear decay rates in stellar-like condition (such as 7Be decay and beta-decay involved in s-process nucleosynthesis), especially as a function of the ionization state of the plasma ions. These studies will give important contributions for addressing several astrophysical issues in both stellar and primordial nucleosynthesis environment ( e.g., determination of solar neutrino flux and 7Li Cosmological Problem), moreover the confined energetic plasma will be a unique light source for high-performance stellar spectroscopy measurements in the visible, UV and X-ray domains, offering advancements in observational astronomy. As to magnetic fields, the experimental validation of theoretical first- and second-order Landé factors will drive the layout of next-generation polarimetric units for the high-resolution spectrograph of the future giant telescopes. In PANDORA new plasma heating methods will be explored, that will push forward the ion beam output, in terms of extracted intensity and charge states. More, advanced and optimized injection methods of ions in an ECR plasma will be experimented, with the aim to optimize its capture efficiency. This will be applied to the ECR-based Charge Breeding technique, that will improve the performances of the SPES ISOL-facility at Laboratori Nazionali di Legnaro-INFN. Finally, PANDORA will be suitable for energy conversion, making the plasma a source of high-intensity electromagnetic radiation, for applications in material science and archaeometry.

The Charge State of Polycyclic Aromatic Hydrocarbons Across Reflection Nebulae: PAH Charge Balance and Calibration

NASA Astrophysics Data System (ADS)

Boersma, C.; Bregman, J.; Allamandola, L. J.

2016-11-01

Low-resolution Spitzer spectral map data (>1700 spectra) of ten reflection nebulae (RNe) fields are analyzed using the data and tools available through the NASA Ames PAH IR Spectroscopic Database. The PAH emission is broken down into PAH charge state using a database fitting approach. Here, the physics of the PAH emission process is taken into account and uses target appropriate parameters, e.g., a stellar radiation model for the exciting star. The breakdown results are combined with results derived using the traditional PAH band strength approach, which interprets particular PAH band strength ratios as proxies for the PAH charge state, e.g., the 6.2/11.2 μm PAH band strength ratio. These are successfully calibrated against their database equivalent; the PAH ionized fraction (f I ). The PAH ionized fraction is converted into the PAH ionization parameter, which relates the PAH ionized fraction to the strength of the radiation field, gas temperature and electron density. The behavior of the 12.7 μm PAH band is evaluated as a tracer for PAH ionization and erosion. The plot of the 8.6 versus 11.2 μm PAH band strength for the northwest photo-dominated region (PDR) in NGC 7023 is shown to be a robust diagnostic template for the PAH ionized fraction. Remarkably, most of the other RNe fall within the limits set by NGC 7023. Finally, PAH spectroscopic templates are constructed and verified as principal components. Template spectra derived from NGC 7023 and NGC 2023 compare extremely well with each other, with those derived for NGC 7023 successfully reproducing the PAH emission observed from NGC 2023.

THE CHARGE STATE OF POLYCYCLIC AROMATIC HYDROCARBONS ACROSS REFLECTION NEBULAE: PAH CHARGE BALANCE AND CALIBRATION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boersma, C.; Bregman, J.; Allamandola, L. J., E-mail: Christiaan.Boersma@nasa.gov

Low-resolution Spitzer spectral map data (>1700 spectra) of ten reflection nebulae (RNe) fields are analyzed using the data and tools available through the NASA Ames PAH IR Spectroscopic Database. The PAH emission is broken down into PAH charge state using a database fitting approach. Here, the physics of the PAH emission process is taken into account and uses target appropriate parameters, e.g., a stellar radiation model for the exciting star. The breakdown results are combined with results derived using the traditional PAH band strength approach, which interprets particular PAH band strength ratios as proxies for the PAH charge state, e.g.,more » the 6.2/11.2 μ m PAH band strength ratio. These are successfully calibrated against their database equivalent; the PAH ionized fraction ( f {sub i} ). The PAH ionized fraction is converted into the PAH ionization parameter, which relates the PAH ionized fraction to the strength of the radiation field, gas temperature and electron density. The behavior of the 12.7 μ m PAH band is evaluated as a tracer for PAH ionization and erosion. The plot of the 8.6 versus 11.2 μ m PAH band strength for the northwest photo-dominated region (PDR) in NGC 7023 is shown to be a robust diagnostic template for the PAH ionized fraction. Remarkably, most of the other RNe fall within the limits set by NGC 7023. Finally, PAH spectroscopic templates are constructed and verified as principal components. Template spectra derived from NGC 7023 and NGC 2023 compare extremely well with each other, with those derived for NGC 7023 successfully reproducing the PAH emission observed from NGC 2023.« less

The cause of spatial structure in solar He I 1083 nm multiplet images

NASA Astrophysics Data System (ADS)

Leenaarts, Jorrit; Golding, Thomas; Carlsson, Mats; Libbrecht, Tine; Joshi, Jayant

2016-10-01

Context. The He I 1083 nm is a powerful diagnostic for inferring properties of the upper solar chromosphere, in particular for the magnetic field. The basic formation of the line in one-dimensional models is well understood, but the influence of the complex three-dimensional structure of the chromosphere and corona has however never been investigated. This structure must play an essential role because images taken in He I 1083 nm show structures with widths down to 100 km. Aims: We aim to understand the effect of the three-dimensional temperature and density structure in the solar atmosphere on the formation of the He I 1083 nm line. Methods: We solved the non-LTE radiative transfer problem assuming statistical equilibrium for a simple nine-level helium atom that nevertheless captures all essential physics. As a model atmosphere we used a snapshot from a 3D radiation-MHD simulation computed with the Bifrost code. Ionising radiation from the corona was self-consistently taken into account. Results: The emergent intensity in the He I 1083 nm is set by the source function and the opacity in the upper chromosphere. The former is dominated by scattering of photospheric radiation and does not vary much with spatial location. The latter is determined by the photonionisation rate in the He I ground state continuum, as well as the electron density in the chromosphere. The spatial variation of the flux of ionising radiation is caused by the spatially-structured emissivity of the ionising photons from material at T ≈ 100 kK in the transition region. The hotter coronal material produces more ionising photons, but the resulting radiation field is smooth and does not lead to small-scale variation of the UV flux. The corrugation of the transition region further increases the spatial variation of the amount of UV radiation in the chromosphere. Finally we find that variations in the chromospheric electron density also cause strong variation in He I 1083 nm opacity. We compare our findings to observations using SST, IRIS and SDO/AIA data. A movie associated to Fig. 4 is available at http://www.aanda.org

A new spin on primordial hydrogen recombination and a refined model for spinning dust radiation

NASA Astrophysics Data System (ADS)

Ali-Haimoud, Yacine

2011-08-01

This thesis describes theoretical calculations in two subjects: the primordial recombination of the electron-proton plasma about 400,000 years after the Big Bang and electric dipole radiation from spinning dust grains in the present-day interstellar medium. Primordial hydrogen recombination has recently been the subject of a renewed attention because of the impact of its theoretical uncertainties on predicted cosmic microwave background (CMB) anisotropy power spectra. The physics of the primordial recombination problem can be divided into two qualitatively different aspects. On the one hand, a detailed treatment of the non-thermal radiation field in the optically thick Lyman lines is required for an accurate recombination history near the peak of the visibility function. On the other hand, stimulated recombinations and out-of equilibrium effects are important at late times and a multilevel calculation is required to correctly compute the low-redshift end of the ionization history. Another facet of the problem is the requirement of computational efficiency, as a large number of recombination histories must be evaluated in Markov chains when analyzing CMB data. In this thesis, an effective multilevel atom method is presented, that speeds up multilevel atom computations by more than 5 orders of magnitude. The impact of previously ignored radiative transfer effects is quantified, and explicitly shown to be negligible. Finally, the numerical implementation of a fast and highly accurate primordial recombination code partly written by the author is described. The second part of this thesis is devoted to one of the potential galactic foregrounds for CMB experiments: the rotational emission from small dust grains. The rotational state of dust grains is described, first classically, and assuming that grains are rotating about their axis of greatest inertia. This assumption is then lifted, and a quantum-mechanical calculation is presented for disk-like grains with a randomized nutation state. In both cases, the probability distribution for the total grain angular momentum is computed with a Fokker-Planck equation, and the resulting emissivity is evaluated, as a function of environmental parameters. These computations are implemented in a public code written by the author.

Polaradiometric pyrometer in which the parallel and perpendicular components of radiation reflected from an unpolarized light source are equalized with the thermal radiation emitted from a measured object to determine its true temperature

NASA Technical Reports Server (NTRS)

Abtahi, Ali A. (Inventor)

1995-01-01

A radiation pyrometer for measuring the true temperature of a body is provided by detecting and measuring thermal radiation from the body based on the principle that the effects of angular emission I(sub 1) and reflection I(sub 2) on the polarization states p and s of radiation are complementary such that upon detecting the combined partial polarization state components I(sub p) =I(sub 1p) + I(sub 2p) and I(sub s)=I(sub 1s) + I(sub 2s) and adjusting the intensity of the variable radiation source of the reflected radiation I(sub 2) until the combined partial radiation components I(sub p) and I(sub s) are equal, the effects of emissivity as well as diffusivity of the surface of the body are eliminated, thus obviating the need for any post processing of brightness temperature data.

[Radiation-induced genomic instability: phenomenon, molecular mechanisms, pathogenetic significance].

PubMed

Mazurik, V K; Mikhaĭlov, V F

2001-01-01

The recent data on the radiation-induced genome instability as a special state of progeny of cells irradiated in vitro as well as after a whole body exposure to ionizing radiation, that make these cells considerably different from normal, unirradiated cells, were considered. This state presents a number of cytogenetical, molecular-biological, cytological and biochemical manifestations untypical for normal cells. The state is controlled by the mechanisms of regulation of checkpoints of cell cycle, and apoptosis, that is under gene p53 control. The proof has been found that this state transfers from irradiated maternal cells to their surviving progeny by the epigenetical mechanisms and would exist until the cells restore the original state of response on the DNA damage. From the point of view of the genome instability conception, that considers the chromatine rearrangement as the adaptive-evolution mechanism of adaptation of the species to changeable environmental conditions, the radiation-induced genome instability may be considered as transition of irradiated progeny to the state of read these to adaptation changes with two alternative pathways. The first leads to adaptation to enviromental conditions and restoring of normal cell functions. The second presents the cell transition into the transformed state with remain genome instability and with increase of tumour growth probability.

Gravitational radiation theory. M.A. Thesis - Rice Univ.; [survey of current research

NASA Technical Reports Server (NTRS)

Wilson, T. L.

1973-01-01

A survey is presented of current research in the theory of gravitational radiation. The mathematical structure of gravitational radiation is stressed. Furthermore, the radiation problem is treated independently from other problems in gravitation. The development proceeds candidly through three points of view - scalar, rector, and tensor radiation theory - and the corresponding results are stated.

Detailed real-time infrared radiation simulation applied to the sea surface

NASA Astrophysics Data System (ADS)

Zhang, Xuemin; Wu, Limin; Long, Liang; Zhang, Lisha

2018-01-01

In this paper, the infrared radiation characteristics of sea background have been studied. First, MODTRAN4.0 was used to calculate the transmittance of mid-infrared and far-infrared, and the solar spectral irradiance, the atmospheric and sea surface radiation. Secondly, according to the JONSWAP sea spectrum model, the different sea conditions grid model based on gravity wave theory was generated. The spectral scattering of the sun and the atmospheric background radiation was studied. The total infrared radiation of the sea surface was calculated. Finally, the infrared radiation of a piece of sea surface was mapped to each pixel of the detector, and the infrared radiation is simulated. The conclusion is that solar radiance has a great influence on the infrared radiance. When the detector angle is close to the sun's height angle, there will be bright spots on the sea surface.

Inconstant sun: how solar evolution has affected cosmic and ultraviolet radiation exposure over the history of life on Earth.

PubMed

Karam, P Andrew

2003-03-01

Four billion years ago, sea-level UV exposure was more than 400 times as intense as today, the dose from solar cosmic rays was five times present levels, and galactic cosmic rays accounted for only about 10% their current contribution to sea-level radiation doses. Exposure to cosmic radiation accounts for about 10% of natural background radiation exposure today and includes dose from galactic cosmic rays and solar charged particles. There is little exposure to ionizing wavelengths of UV due to absorption by ozone. The sun has evolved significantly over its life; in the past there were higher levels of particulate radiation and lower UV emissions from the sun, and a stronger solar wind reduced radiation dose in the inner solar system from galactic cosmic rays. Finally, since the early atmosphere contained little to no oxygen, surface levels of UV radiation were far higher in the past.

Comparison of Coupled Radiative Flow Solutions with Project Fire 2 Flight Data

NASA Technical Reports Server (NTRS)

Olynick, David R.; Henline, W. D.; Chambers, Lin Hartung; Candler, G. V.

1995-01-01

A nonequilibrium, axisymmetric, Navier-Stokes flow solver with coupled radiation has been developed for use in the design or thermal protection systems for vehicles where radiation effects are important. The present method has been compared with an existing now and radiation solver and with the Project Fire 2 experimental data. Good agreement has been obtained over the entire Fire 2 trajectory with the experimentally determined values of the stagnation radiation intensity in the 0.2-6.2 eV range and with the total stagnation heating. The effects of a number of flow models are examined to determine which combination of physical models produces the best agreement with the experimental data. These models include radiation coupling, multitemperature thermal models, and finite rate chemistry. Finally, the computational efficiency of the present model is evaluated. The radiation properties model developed for this study is shown to offer significant computational savings compared to existing codes.

Sponge budding is a spatiotemporal morphological patterning process: Insights from synchrotron radiation-based x-ray microtomography into the asexual reproduction of Tethya wilhelma.

PubMed

Hammel, Jörg U; Herzen, Julia; Beckmann, Felix; Nickel, Michael

2009-09-08

Primary agametic-asexual reproduction mechanisms such as budding and fission are present in all non-bilaterian and many bilaterian animal taxa and are likely to be metazoan ground pattern characters. Cnidarians display highly organized and regulated budding processes. In contrast, budding in poriferans was thought to be less specific and related to the general ability of this group to reorganize their tissues. Here we test the hypothesis of morphological pattern formation during sponge budding. We investigated the budding process in Tethya wilhelma (Demospongiae) by applying 3D morphometrics to high resolution synchrotron radiation-based x-ray microtomography (SR-muCT) image data. We followed the morphogenesis of characteristic body structures and identified distinct morphological states which indeed reveal characteristic spatiotemporal morphological patterns in sponge bud development. We discovered the distribution of skeletal elements, canal system and sponge tissue to be based on a sequential series of distinct morphological states. Based on morphometric data we defined four typical bud stages. Once they have reached the final stage buds are released as fully functional juvenile sponges which are morphologically and functionally equivalent to adult specimens. Our results demonstrate that budding in demosponges is considerably more highly organized and regulated than previously assumed. Morphological pattern formation in asexual reproduction with underlying genetic regulation seems to have evolved early in metazoans and was likely part of the developmental program of the last common ancestor of all Metazoa (LCAM).

Sponge budding is a spatiotemporal morphological patterning process: Insights from synchrotron radiation-based x-ray microtomography into the asexual reproduction of Tethya wilhelma

PubMed Central

Hammel, Jörg U; Herzen, Julia; Beckmann, Felix; Nickel, Michael

2009-01-01

Background Primary agametic-asexual reproduction mechanisms such as budding and fission are present in all non-bilaterian and many bilaterian animal taxa and are likely to be metazoan ground pattern characters. Cnidarians display highly organized and regulated budding processes. In contrast, budding in poriferans was thought to be less specific and related to the general ability of this group to reorganize their tissues. Here we test the hypothesis of morphological pattern formation during sponge budding. Results We investigated the budding process in Tethya wilhelma (Demospongiae) by applying 3D morphometrics to high resolution synchrotron radiation-based x-ray microtomography (SR-μCT) image data. We followed the morphogenesis of characteristic body structures and identified distinct morphological states which indeed reveal characteristic spatiotemporal morphological patterns in sponge bud development. We discovered the distribution of skeletal elements, canal system and sponge tissue to be based on a sequential series of distinct morphological states. Based on morphometric data we defined four typical bud stages. Once they have reached the final stage buds are released as fully functional juvenile sponges which are morphologically and functionally equivalent to adult specimens. Conclusion Our results demonstrate that budding in demosponges is considerably more highly organized and regulated than previously assumed. Morphological pattern formation in asexual reproduction with underlying genetic regulation seems to have evolved early in metazoans and was likely part of the developmental program of the last common ancestor of all Metazoa (LCAM). PMID:19737392

Natural and Anthropogenic Aerosol Trends from Satellite and Surface Observations and Model Simulations over the North Atlantic Ocean from 2002 to 2012

NASA Technical Reports Server (NTRS)

Jongeward, Andrew R.; Li, Zhanqing; He, Hao; Xiong, Xiaoxiong

2016-01-01

Aerosols contribute to Earths radiative budget both directly and indirectly, and large uncertainties remain in quantifying aerosol effects on climate. Variability in aerosol distribution and properties, as might result from changing emissions and transport processes, must be characterized. In this study, variations in aerosol loading across the eastern seaboard of theUnited States and theNorthAtlanticOcean during 2002 to 2012 are analyzed to examine the impacts of anthropogenic emission control measures using monthly mean data from MODIS, AERONET, and IMPROVE observations and Goddard Chemistry Aerosol Radiation and Transport (GOCART) model simulation.MODIS observes a statistically significant negative trend in aerosol optical depth (AOD) over the midlatitudes (-0.030 decade(sup-1)). Correlation analyses with surface AOD from AERONET sites in the upwind region combined with trend analysis from GOCART component AOD confirm that the observed decrease in the midlatitudes is chiefly associated with anthropogenic aerosols that exhibit significant negative trends from the eastern U.S. coast extending over the western North Atlantic. Additional analysis of IMPROVE surface PM(sub 2.5) observations demonstrates statistically significant negative trends in the anthropogenic components with decreasing mass concentrations over the eastern United States. Finally, a seasonal analysis of observational datasets is performed. The negative trend seen by MODIS is strongest during spring (MAM) and summer (JJA) months. This is supported by AERONET seasonal trends and is identified from IMPROVE seasonal trends as resulting from ammonium sulfate decreases during these seasons.

Infrared problem in quantum acoustodynamics

NASA Astrophysics Data System (ADS)

Clougherty, Dennis P.; Sengupta, Sanghita

2017-05-01

Quantum electrodynamics (QED) provides a highly accurate description of phenomena involving the interaction of atoms with light. We argue that the quantum theory describing the interaction of cold atoms with a vibrating membrane—quantum acoustodynamics (QAD)—shares many issues and features with QED. Specifically, the adsorption of an atom on a vibrating membrane can be viewed as the counterpart to QED radiative electron capture. A calculation of the adsorption rate to lowest order in the atom-phonon coupling is finite; however, higher-order contributions suffer from an infrared problem mimicking the case of radiative capture in QED. Terms in the perturbation series for the adsorption rate diverge as a result of massless particles in the model (flexural phonons of the membrane in QAD and photons in QED). We treat this infrared problem in QAD explicitly to obtain finite results by regularizing with a low-frequency cutoff that corresponds to the inverse size of the membrane. Using a coherent-state basis for the soft-phonon final state, we then sum the dominant contributions to derive a new formula for the multiphonon adsorption rate of atoms on the membrane that gives results that are finite, nonperturbative in the atom-phonon coupling, and consistent with the Kinoshita-Lee-Nauenberg theorem. For micromembranes, we predict a reduction with increasing membrane size for the low-energy adsorption rate. We discuss the relevance of this to the adsorption of a cold gas of atomic hydrogen on suspended graphene.

Interpreting Chromosome Aberration Spectra

NASA Technical Reports Server (NTRS)

Levy, Dan; Reeder, Christopher; Loucas, Bradford; Hlatky, Lynn; Chen, Allen; Cornforth, Michael; Sachs, Rainer

2007-01-01

Ionizing radiation can damage cells by breaking both strands of DNA in multiple locations, essentially cutting chromosomes into pieces. The cell has enzymatic mechanisms to repair such breaks; however, these mechanisms are imperfect and, in an exchange process, may produce a large-scale rearrangement of the genome, called a chromosome aberration. Chromosome aberrations are important in killing cells, during carcinogenesis, in characterizing repair/misrepair pathways, in retrospective radiation biodosimetry, and in a number of other ways. DNA staining techniques such as mFISH ( multicolor fluorescent in situ hybridization) provide a means for analyzing aberration spectra by examining observed final patterns. Unfortunately, an mFISH observed final pattern often does not uniquely determine the underlying exchange process. Further, resolution limitations in the painting protocol sometimes lead to apparently incomplete final patterns. We here describe an algorithm for systematically finding exchange processes consistent with any observed final pattern. This algorithm uses aberration multigraphs, a mathematical formalism that links the various aspects of aberration formation. By applying a measure to the space of consistent multigraphs, we will show how to generate model-specific distributions of aberration processes from mFISH experimental data. The approach is implemented by software freely available over the internet. As a sample application, we apply these algorithms to an aberration data set, obtaining a distribution of exchange cycle sizes, which serves to measure aberration complexity. Estimating complexity, in turn, helps indicate how damaging the aberrations are and may facilitate identification of radiation type in retrospective biodosimetry.

History and Organizations for Radiological Protection.

PubMed

Kang, Keon Wook

2016-02-01

International Commission on Radiological Protection (ICRP), an independent international organization established in 1925, develops, maintains, and elaborates radiological protection standards, legislation, and guidelines. United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) provides scientific evidence. World Health Organization (WHO) and International Atomic Energy Agency (IAEA) utilise the ICRP recommendations to implement radiation protection in practice. Finally, radiation protection agencies in each country adopt the policies, and adapt them to each situation. In Korea, Nuclear Safety and Security Commission is the governmental body for nuclear safety regulation and Korea Institute of Nuclear Safety is a public organization for technical support and R&D in nuclear safety and radiation protection.

A 1D radiative transfer benchmark with polarization via doubling and adding

NASA Astrophysics Data System (ADS)

Ganapol, B. D.

2017-11-01

Highly precise numerical solutions to the radiative transfer equation with polarization present a special challenge. Here, we establish a precise numerical solution to the radiative transfer equation with combined Rayleigh and isotropic scattering in a 1D-slab medium with simple polarization. The 2-Stokes vector solution for the fully discretized radiative transfer equation in space and direction derives from the method of doubling and adding enhanced through convergence acceleration. Updates to benchmark solutions found in the literature to seven places for reflectance and transmittance as well as for angular flux follow. Finally, we conclude with the numerical solution in a partially randomly absorbing heterogeneous medium.

Design and development of a hard tube flexible radiator system

NASA Technical Reports Server (NTRS)

Hixon, C. W.

1980-01-01

The construction and operational characteristics of an extended life flexible radiator panel is described. The radiator panel consists of a flexible fin laminate and stainless steel flow tubes designed for a 90 percent probability of surviving 5 years in an Earth orbit micrometeoroid environment. The radiator panel rejects 1.1 kW sub t of heat into an environmental sink temperature of 0 F. Total area is 170 square feet and the panel extends 25 feet in the fully deployed position. When retracted the panel rolls onto a 11.5 inch diameter by 52 inch long storage drum, for a final stored diameter of 22 inches.

Classification of Reactor Facility Operational State Using SPRT Methods with Radiation Sensor Networks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ramirez Aviles, Camila A.; Rao, Nageswara S.

We consider the problem of inferring the operational state of a reactor facility by using measurements from a radiation sensor network, which is deployed around the facility’s ventilation stack. The radiation emissions from the stack decay with distance, and the corresponding measurements are inherently random with parameters determined by radiation intensity levels at the sensor locations. We fuse measurements from network sensors to estimate the intensity at the stack, and use this estimate in a one-sided Sequential Probability Ratio Test (SPRT) to infer the on/off state of the reactor facility. We demonstrate the superior performance of this method over conventionalmore » majority vote fusers and individual sensors using (i) test measurements from a network of NaI sensors, and (ii) emulated measurements using radioactive effluents collected at a reactor facility stack. We analytically quantify the performance improvements of individual sensors and their networks with adaptive thresholds over those with fixed ones, by using the packing number of the radiation intensity space.« less

NCRP report 160 and what it means for medical imaging and nuclear medicine.

PubMed

Bolus, Norman E

2013-12-01

The purpose of this paper is to briefly explain report 160 of the National Council on Radiation Protection and Measurement and the significance of the report to medical imaging as a whole and nuclear medicine specifically. The implications of the findings of report 160 have had repercussions and will continue to affect all of ionizing radiation medical imaging. The nuclear medicine community should have an understanding of why and how report 160 is important. After reading this article, the nuclear medicine technologist will be familiar with the main focus of report 160, the significant change that has occurred since the 1980s in the ionizing radiation exposure of people in the United States, the primary background source of ionizing radiation in the United States, the primary medical exposure to ionizing radiation in the United States, trends in nuclear medicine procedures and patient exposure, and a comparison of population doses between 2006 and the early 1980s as outlined in report 160.

Radically Reducing Radiation Exposure during Routine Medical Imaging

Cancer.gov

Exposure to radiation from medical imaging in the United States has increased dramatically. NCI and several partner organizations sponsored a 2011 summit to promote efforts to reduce radiation exposure from medical imaging.

Quantum information processing with long-wavelength radiation

NASA Astrophysics Data System (ADS)

Murgia, David; Weidt, Sebastian; Randall, Joseph; Lekitsch, Bjoern; Webster, Simon; Navickas, Tomas; Grounds, Anton; Rodriguez, Andrea; Webb, Anna; Standing, Eamon; Pearce, Stuart; Sari, Ibrahim; Kiang, Kian; Rattanasonti, Hwanjit; Kraft, Michael; Hensinger, Winfried

To this point, the entanglement of ions has predominantly been performed using lasers. Using long wavelength radiation with static magnetic field gradients provides an architecture to simplify construction of a large scale quantum computer. The use of microwave-dressed states protects against decoherence from fluctuating magnetic fields, with radio-frequency fields used for qubit manipulation. I will report the realisation of spin-motion entanglement using long-wavelength radiation, and a new method to efficiently prepare dressed-state qubits and qutrits, reducing experimental complexity of gate operations. I will also report demonstration of ground state cooling using long wavelength radiation, which may increase two-qubit entanglement fidelity. I will then report demonstration of a high-fidelity long-wavelength two-ion quantum gate using dressed states. Combining these results with microfabricated ion traps allows for scaling towards a large scale ion trap quantum computer, and provides a platform for quantum simulations of fundamental physics. I will report progress towards the operation of microchip ion traps with extremely high magnetic field gradients for multi-ion quantum gates.

Interaction region design driven by energy deposition

NASA Astrophysics Data System (ADS)

Martin, Roman; Besana, Maria Ilaria; Cerutti, Francesco; Langner, Andy; Tomás, Rogelio; Cruz-Alaniz, Emilia; Dalena, Barbara

2017-08-01

The European Strategy Group for High Energy Physics recommends to study collider designs for the post-LHC era. Among the suggested projects there is the circular 100 TeV proton-proton collider FCC-hh. Starting from LHC and its proposed upgrade HL-LHC, this paper outlines the development of the interaction region design for FCC-hh. We identify energy deposition from debris of the collision events as a driving factor for the layout and draft the guiding principles to unify protection of the superconducting final focus magnets from radiation with a high luminosity performance. Furthermore, we offer a novel strategy to mitigate the lifetime limitation of the first final focus magnet due to radiation load, the Q1 split.

Space radiator simulation manual for computer code

NASA Technical Reports Server (NTRS)

Black, W. Z.; Wulff, W.

1972-01-01

A computer program that simulates the performance of a space radiator is presented. The program basically consists of a rigorous analysis which analyzes a symmetrical fin panel and an approximate analysis that predicts system characteristics for cases of non-symmetrical operation. The rigorous analysis accounts for both transient and steady state performance including aerodynamic and radiant heating of the radiator system. The approximate analysis considers only steady state operation with no aerodynamic heating. A description of the radiator system and instructions to the user for program operation is included. The input required for the execution of all program options is described. Several examples of program output are contained in this section. Sample output includes the radiator performance during ascent, reentry and orbit.

Assessment of the Effect of Air Pollution Controls on Trends in Shortwave Radiation over the United States from 1995 through 2010 from Multiple Observation Networks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gan, Chuen-Meei; Pleim, Jonathan; Mathur, Rohit

2014-02-14

Long term datasets of total (all-sky) and clear-sky downwelling shortwave (SW) radiation, cloud cover fraction (cloudiness) and aerosol optical depth (AOD) are analyzed together with aerosol concentration from several networks (e.g. SURFRAD, CASTNET, IMPROVE and ARM) in the United States (US). Seven states with varying climatology are selected to better understand the effect of aerosols and clouds on SW radiation. This analysis aims to test the hypothesis that the reductions in anthropogenic aerosol burden resulting from substantial reductions in emissions of sulfur dioxide and nitrogen oxides over the past 15 years across the US has caused an increase in surfacemore » SW radiation. We show that the total and clear-sky downwelling SW radiation from seven sites have increasing trends except Penn State which shows no tendency in clear-sky SW radiation. After investigating several confounding factors, the causes can be due to the geography of the site, aerosol distribution, heavy air traffic and increasing cloudiness. Moreover, we assess the relationship between total column AOD with surface aerosol concentration to test our hypothesis. In our findings, the trends of clear-sky SW radiation, AOD, and aerosol concentration from the sites in eastern US agree well with our hypothesis. However, the sites in western US demonstrate increasing AOD associated with mostly increasing trends in surface aerosol concentration. At these sites, the changes in aerosol burden and/or direct aerosol effects alone cannot explain the observed changes in SW radiation, but other factors need to be considered such as cloudiness, aerosol vertical profiles and elevated plumes.« less

An adjustable short-focal length, high-gradient PMQ electron-beam final-focus system for the PLEIADES ultra-fast x-ray Thomson source

NASA Astrophysics Data System (ADS)

Lim, Jae-Ku

In the span of a 100 year since the discovery of first x-rays by Roentgen that won him the first Nobel prize in physics, several types of radiation sources have been developed. Currently, radiations at extremely short wavelengths have only been accessed at synchrotron radiation sources. However, the current 3rd generation synchrotron sources can only produce x-rays of energy up to 60 keV and pulse lengths of several picoseconds long. But needs for shorter wavelength and shorter pulse duration radiations demanded by scientists to understand the nature of matter at atomic/molecular scale initiated the new scientific research for the production of sub-picosecond, hard x-rays. At the Lawrence Livermore National Laboratory, a Thomson x-ray source in the backscattering mode---a head-on collision between a high intensity Ti:Sapphire Chirped Pulse Amplification laser and a relativistic electron beam---called the PLEIADES (Picosecond Laser-Electron Inter-Action for the Dynamical Evaluation of Structures) laboratory has been developed. Early works demonstrated the production of quasi-monochromatic, femto-second long, hard x-rays. Initially reported x-ray flux was in the low range of 105--10 6 photons per shot. During the early stage of PLEIADES experiments, 15 T/m electromagnet final focusing quadrupoles (in a triplet lattice configuration) were employed to focus the beam to a 40-50 mum spot-size. A larger focal spot-size beam has a low-density of electron particles available at the interaction with incident photons, which leads to a low scattering probability. The current dissertation shows that by employing a 560 T/m PMQ (Permanent-Magnet Quadrupole) final focus system, an electron beam as small as 10-20 mum can be achieved. The implementation of this final focus system demonstrated the improvement of the total x-ray flux by two orders of magnitude. The PMQ final focus system also produced small electron beams consistently over 30-100 MeV electron beam energy, which enabled the production of x-ray energy over 40-140 keV. In this dissertation, the PLEIADES Thomson x-ray facility will be described in detail includes the 100 MeV linac and the FALCON laser system. Later, we will discuss the design, construction and implementation of the PMQ final focus system in the beamline. The measurement of electron beam parameters before and after the final focus system will be presented. The beam measurements at the interaction region were accomplished with the use of both OTR (Optical Transition Radiation) imaged by a CCD camera and the fast streak camera for respective spatial and temporal alignments. The theoretical analysis in "real beam" effects and spacetime beam jitter effects will be given to help understand the observations. A 3D simulation tool developed for x-ray data analysis was used to provide direct comparisons with the x-ray flux, spectrum distribution and transverse x-ray profile.

Photo-excited zero-resistance states in quasi-two-dimensional GaAs / Al xGa 1- xAs devices

NASA Astrophysics Data System (ADS)

Mani, R. G.

2007-12-01

We illustrate some experimental features of the recently discovered radiation-induced zero-resistance states in the high-mobility GaAs/AlGaAs system, with a special emphasis on the interplay between the radiation-induced changes in the diagonal resistance and the Hall effect. We show that, quantum Hall effects, i.e., quantum Hall plateaus, disappear under photoexcitation, at the minima of the radiation-induced magnetoresistance oscillations.

Fading Hawking radiation

NASA Astrophysics Data System (ADS)

Sakalli, Izzet; Halilsoy, Mustafa; Pasaoglu, Hale

2012-07-01

In this study, we explore a particular type Hawking radiation which ends with zero temperature and entropy. The appropriate black holes for this purpose are the linear dilaton black holes. In addition to the black hole choice, a recent formalism in which the Parikh-Wilczek's tunneling formalism amalgamated with quantum corrections to all orders in ħ is considered. The adjustment of the coefficients of the quantum corrections plays a crucial role on this particular Hawking radiation. The obtained tunneling rate indicates that the radiation is not pure thermal anymore, and hence correlations of outgoing quanta are capable of carrying away information encoded within them. Finally, we show in detail that when the linear dilaton black hole completely evaporates through such a particular radiation, entropy of the radiation becomes identical with the entropy of the black hole, which corresponds to "no information loss".

Radiative lifetimes of the CN (A 2 Pi i) electronic state

NASA Technical Reports Server (NTRS)

Lu, Richang; Huang, Yuhui; Halpern, Joshua B.

1992-01-01

Radiative lifetimes have been measured for CN (A 2 Pi i v-prime = 2...7). Ground-state radicals formed in the 193 nm photolysis of C2N2 and ClCN were excited to A 2 Pi i v-prime = 2...7 vibrational levels. The decay was monitored by following the fluorescence. Cascading effects were eliminated by working at low pressures and monitoring emission from a single vibrational band. Quenching rates and zero-pressure radiative lifetimes were obtained from Stern-Volmer plots. The lifetimes are significantly lower than previous measurements and theoretical calculations for vibrational states v-prime over 2.

Temperature controlled high voltage regulator

DOEpatents

Chiaro, Jr., Peter J.; Schulze, Gerald K.

2004-04-20

A temperature controlled high voltage regulator for automatically adjusting the high voltage applied to a radiation detector is described. The regulator is a solid state device that is independent of the attached radiation detector, enabling the regulator to be used by various models of radiation detectors, such as gas flow proportional radiation detectors.

6th International Conference on Biophysics & Synchrotron Radiation. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moffat, Keith

1999-08-03

The 6th International Conference on Biophysics and Synchrotron Rdiation was held at the Advanced Photon Source, Argonne National Laboratory, from August 4-8, 1998, with pre-conference activities on August 3. Over 300 attendees and 65 presenters participated in the conference that was collaboratively hosted by the University of Chicago, Center for Advanced Radiation Sources and the Advanced Photon Source.

Simulation of planetary entry radiative heating with a CO2 gasdynamic laser

NASA Technical Reports Server (NTRS)

Lundell, J. H.; Dickey, R. R.; Howe, J. T.

1975-01-01

Heating encountered during entry into the atmospheres of Jupiter, Saturn, and Uranus is described, followed by a discussion of the use of a CO2 gasdynamic laser to simulate the radiative component of the heating. Operation and performance of the laser is briefly described. Finally, results of laser tests of some candidate heat-shield materials are presented.

Collaborative Project. 3D Radiative Transfer Parameterization Over Mountains/Snow for High-Resolution Climate Models. Fast physics and Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liou, Kuo-Nan

2016-02-09

Under the support of the aforementioned DOE Grant, we have made two fundamental contributions to atmospheric and climate sciences: (1) Develop an efficient 3-D radiative transfer parameterization for application to intense and intricate inhomogeneous mountain/snow regions. (2) Innovate a stochastic parameterization for light absorption by internally mixed black carbon and dust particles in snow grains for understanding and physical insight into snow albedo reduction in climate models. With reference to item (1), we divided solar fluxes reaching mountain surfaces into five components: direct and diffuse fluxes, direct- and diffuse-reflected fluxes, and coupled mountain-mountain flux. “Exact” 3D Monte Carlo photon tracingmore » computations can then be performed for these solar flux components to compare with those calculated from the conventional plane-parallel (PP) radiative transfer program readily available in climate models. Subsequently, Parameterizations of the deviations of 3D from PP results for five flux components are carried out by means of the multiple linear regression analysis associated with topographic information, including elevation, solar incident angle, sky view factor, and terrain configuration factor. We derived five regression equations with high statistical correlations for flux deviations and successfully incorporated this efficient parameterization into WRF model, which was used as the testbed in connection with the Fu-Liou-Gu PP radiation scheme that has been included in the WRF physics package. Incorporating this 3D parameterization program, we conducted simulations of WRF and CCSM4 to understand and evaluate the mountain/snow effect on snow albedo reduction during seasonal transition and the interannual variability for snowmelt, cloud cover, and precipitation over the Western United States presented in the final report. With reference to item (2), we developed in our previous research a geometric-optics surface-wave approach (GOS) for the computation of light absorption and scattering by complex and inhomogeneous particles for application to aggregates and snow grains with external and internal mixing structures. We demonstrated that a small black (BC) particle on the order of 1 μm internally mixed with snow grains could effectively reduce visible snow albedo by as much as 5–10%. Following this work and within the context of DOE support, we have made two key accomplishments presented in the attached final report.« less

Radiative Feedback from Primordial Protostars and Final Mass of the First Stars

NASA Technical Reports Server (NTRS)

Hosokawa, Takashi; Omukai, Kazuyuki; Yoshida, Naoki; Yorke, Harold W.

2012-01-01

In this contribution, we review our efforts toward understanding the typical mass-scale of primordial stars. Our direct numerical simulations show that, in both of Population III.1 and III.2 cases, strong UV stellar radiative feedback terminatesmass accretion onto a protostar.AnHII region formed around the protostar very dynamically expands throughout the gas accreting envelope, which cuts off the gas supply to a circumstellar disk. The disk is exposed to the stellar UV radiation and loses its mass by photoevaporation. The derived final masses are 43 Stellar Mass and 17 Stellar Mass in our fiducial Population III.1 and III.2 cases. Much more massive stars should form in other exceptional conditions. In atomic-cooling halos where H2 molecules are dissociated, for instance, a protostar grows via very rapid mass accretion with the rates M* approx. 0.1 - 1 Stellar Mass/yr. Our newstellar evolution calculations show that the protostar significantly inflates and never contracts to reach the ZAMS stage in this case. Such the "supergiant protostars" have very low UV luminosity, which results in weak radiative feedback against the accretion flow. In the early universe, supermassive stars formed through this process might provide massive seeds of supermassive black holes.

NATIONAL- AND STATE-LEVEL EMISSIONS ESTIMATES OF RADIATIVELY IMPORTANT TRACE GASES (RITGS) FROM ANTHROPOGENIC SOURCES

EPA Science Inventory

The report documents the development of national- and state- level emissions estimates of radiatively important trace gases (RlTGs). Emissions estimates are presented for the principal anthropogenic sources of carbon dioxide (CO2), methane (CH4), chlorofluorocarbons (CFCs), and o...

LINKING REGIONAL AEROSOL EMISSION CHANGES WITH MULTIPLE IMPACT MEASURES THROUGH DIRECT AND CLOUD-RELATED FORCING ESTIMATES

EPA Science Inventory

Outputs expected from this project include improved confidence in direct radiative forcing and cloud radiative forcing, particularly over the United States and with regard to United States emissions publicly available, documented data sets including emission inventories of siz...

Nudat 2

Science.gov Websites

modes), gamma rays (energy, intensity, multipolarity, coinc.) Nuclear Wallet Cards Search Latest Ground NuDat 2.7 Levels and Gammas Search Ground and excited states (energy, T1/2, spin/parity, decay and isomeric states properties Decay Radiation Search Radiation type, energy, intensity and dose

[UV-radiation--sources, wavelength, environment].

PubMed

Hölzle, Erhard; Hönigsmann, Herbert

2005-09-01

The UV-radiation in our environment is part of the electromagnetic radiation, which emanates from the sun. It is designated as optical radiation and reaches from 290-4,000 nm on the earth's surface. According to international definitions UV irradiation is divided into short-wave UVC (200-280 nm), medium-wave UVB (280-320 nm), and long-wave UVA (320-400 nm). Solar radiation which reaches the surface of the globe at a defined geographical site and a defined time point is called global radiation. It is modified quantitatively and qualitatively while penetrating the atmosphere. Besides atmospheric conditions, like ozone layer and air pollution, geographic latitude, elevation, time of the season, time of the day, cloudiness and the influence of indirect radiation resulting from stray effects in the atmosphere and reflection from the underground play a role in modifying global radiation, which finally represents the biologically effective radiation. The radiation's distribution on the body surface varies according to sun angle and body posture. The cumulative UV exposure is mainly influenced by outdoor profession and recreational activities. The use of sun beds and phototherapeutic measures additionally may contribute to the cumulative UV dose.

Low-mass dielectrons in pp, p-Pb and Pb-Pb collisions measured by the ALICE Experiment

NASA Astrophysics Data System (ADS)

Vorobyev, Ivan

2018-02-01

Dielectrons produced in ultra-relativistic heavy-ion collisions at the LHC provide a unique probe of the system evolution as they are unperturbed by final-state interactions. The dielectron continuum is extremely rich in physics sources: on top of ordinary Dalitz and resonance decays of pseudoscalar and vector mesons, thermal black-body radiation is of particular interest as it carries information about the temperature of the hot and dense system created in such collisions. The dielectron invariant-mass distribution is furthermore sensitive to medium modifications of the spectral function of short-lived vector mesons that are linked to the potential restoration of chiral symmetry at high temperatures. Correlated electron pairs from semi-leptonic charm and beauty decays provide complementary information about the heavy-quark energy loss.

Women's health in spaceflight.

PubMed

Drudi, Laura; Grenon, S Marlene

2014-06-01

To review the current state of knowledge with regards to clinical challenges related to women's health during spaceflight. Articles were reviewed relevant to "women", "sex," and "gender" in "microgravity," "weightlessness," and "spaceflight" in the English and Russian languages. There were 50 papers identified. Studies have shown that crewmembers suffer from space motion sickness, but gender discrepancies have not been explored. Nearly all women experience orthostatic intolerance in space, which may be due to differences in female cardiovascular response. Immunosuppression in spaceflight results in susceptibility to opportunistic infections, but no studies have investigated gender differences. Finally, radiation exposure and germ cell viability influence the reproductive health of astronauts. With changes in space access offered by commercial space activities, research areas devoted to women's health in microgravity should become one of the priorities for safe space exploratory efforts.

Watching a Black Hole Feed: Sgr A* in the X-ray and Infrared

NASA Astrophysics Data System (ADS)

Fazio, Giovanni

2017-09-01

Black hole accretion drives extreme astrophysical phenomena in the universe. Sgr A*, the nearest supermassive black hole, is highly variable, but sparse data and short observations preclude determination of its emission physics. Despite enormous advances in accretion models in recent years, even the radiation mechanisms of Sgr A* are still unknown. Because the needed information is encoded in the time-dependent relationship between X-ray and IR emission, we propose four new epochs of Chandra monitoring with Spitzer at 4.5 microns. This will double the exposure time for X-ray flares where the NIR state is known, moving us out of the realm of small-number statistics and enabling diagnostics of the true X-ray/IR relationship. This will be the final chance for Chandra+Spitzer observations.

Electroweak Corrections to pp→μ^{+}μ^{-}e^{+}e^{-}+X at the LHC: A Higgs Boson Background Study.

PubMed

Biedermann, B; Denner, A; Dittmaier, S; Hofer, L; Jäger, B

2016-04-22

The first complete calculation of the next-to-leading-order electroweak corrections to four-lepton production at the LHC is presented, where all off-shell effects of intermediate Z bosons and photons are taken into account. Focusing on the mixed final state μ^{+}μ^{-}e^{+}e^{-}, we study differential cross sections that are particularly interesting for Higgs boson analyses. The electroweak corrections are divided into photonic and purely weak corrections. The former exhibit patterns familiar from similar W- or Z-boson production processes with very large radiative tails near resonances and kinematical shoulders. The weak corrections are of the generic size of 5% and show interesting variations, in particular, a sign change between the regions of resonant Z-pair production and the Higgs signal.

Calculation of the total electron excitation cross section in the Born approximation using Slater wave functions for the Li (2s yields 2p), Li (2s yields 3p), Na (3s yields 4p), Mg (3p yields 4s), Ca (4s yields 4p) and K (4s yields 4p) excitations. M.S. Thesis

NASA Technical Reports Server (NTRS)

Simsic, P. L.

1974-01-01

Excitation of neutral atoms by inelastic scattering of incident electrons in gaseous nebulae were investigated using Slater Wave functions to describe the initial and final states of the atom. Total cross sections using the Born Approximation are calculated for: Li(2s yields 2p), Na(3s yields 4p), k(4s yields 4p). The intensity of emitted radiation from gaseous nebulae is also calculated, and Maxwell distribution is employed to average the kinetic energy of electrons.

Color Coherent Radiation in Multi - Jet Events from $$p\\overline{p}$$ Collisions at $$\\sqrt{s}$$ = 1.8-TeV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cullen-Vidal, David Edward

1997-01-01

Results from a study of color coherence phenomena in multi-jet events produced bymore » $$p\\overline{p}$$ collisions are presented. Approximately 13 $$pb^{-1}$$ of data were collected by the D0 detector during the 1992-1993 run of the Fermilab Tevatron $$p\\overline{p}$$ collider at a center of mass energy of $$\\sqrt{s}$$ = 1.8 TeV. Demonstration of initial-to-final state color interference effects is done by measuring spatial correlations between the softer third jet and the second leading-$$E_{\\tau}$$ jet in the events. The data are compared to several Monte Carlo simulations with different color coherence implementations and to the predictions of a Next-to-Leading Order parton level calculation.« less

State-of-the-art molecular imaging in esophageal cancer management: implications for diagnosis, prognosis, and treatment

PubMed Central

Lin, Jolinta; Kligerman, Seth; Goel, Rakhi; Sajedi, Payam; Suntharalingam, Mohan

2015-01-01

Molecular imaging techniques are increasingly being used in addition to standard imaging methods such as endoscopic ultrasound (EUS) and computed tomography (CT) for many cancers including those of the esophagus. In this review, we will discuss the utility of the most widely used molecular imaging technique, 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET). 18F-FDG PET has a variety of potential applications ranging from improving staging accuracy at the time of initial diagnosis to assisting in radiation target volume delineation. Furthermore, 18F-FDG PET can be used to evaluate treatment response after completion of neoadjuvant therapy or potentially during neoadjuvant therapy. Finally, we will also discuss other novel molecular imaging techniques that have potential to further improve cancer care. PMID:25642333

Multisource Estimation of Long-term Global Terrestrial Surface Radiation

NASA Astrophysics Data System (ADS)

Peng, L.; Sheffield, J.

2017-12-01

Land surface net radiation is the essential energy source at the earth's surface. It determines the surface energy budget and its partitioning, drives the hydrological cycle by providing available energy, and offers heat, light, and energy for biological processes. Individual components in net radiation have changed historically due to natural and anthropogenic climate change and land use change. Decadal variations in radiation such as global dimming or brightening have important implications for hydrological and carbon cycles. In order to assess the trends and variability of net radiation and evapotranspiration, there is a need for accurate estimates of long-term terrestrial surface radiation. While large progress in measuring top of atmosphere energy budget has been made, huge discrepancies exist among ground observations, satellite retrievals, and reanalysis fields of surface radiation, due to the lack of observational networks, the difficulty in measuring from space, and the uncertainty in algorithm parameters. To overcome the weakness of single source datasets, we propose a multi-source merging approach to fully utilize and combine multiple datasets of radiation components separately, as they are complementary in space and time. First, we conduct diagnostic analysis of multiple satellite and reanalysis datasets based on in-situ measurements such as Global Energy Balance Archive (GEBA), existing validation studies, and other information such as network density and consistency with other meteorological variables. Then, we calculate the optimal weighted average of multiple datasets by minimizing the variance of error between in-situ measurements and other observations. Finally, we quantify the uncertainties in the estimates of surface net radiation and employ physical constraints based on the surface energy balance to reduce these uncertainties. The final dataset is evaluated in terms of the long-term variability and its attribution to changes in individual components. The goal of this study is to provide a merged observational benchmark for large-scale diagnostic analyses, remote sensing and land surface modeling.

Quantitative theoretical analysis of lifetimes and decay rates relevant in laser cooling BaH

NASA Astrophysics Data System (ADS)

Moore, Keith; Lane, Ian C.

2018-05-01

Tiny radiative losses below the 0.1% level can prove ruinous to the effective laser cooling of a molecule. In this paper the laser cooling of a hydride is studied with rovibronic detail using ab initio quantum chemistry in order to document the decays to all possible electronic states (not just the vibrational branching within a single electronic transition) and to identify the most populated final quantum states. The effect of spin-orbit and associated couplings on the properties of the lowest excited states of BaH are analysed in detail. The lifetimes of the A2Π1/2, H2Δ3/2 and E2Π1/2 states are calculated (136 ns, 5.8 μs and 46 ns respectively) for the first time, while the theoretical value for B2 Σ1/2+ is in good agreement with experiments. Using a simple rate model the numbers of absorption-emission cycles possible for both one- and two-colour cooling on the competing electronic transitions are determined, and it is clearly demonstrated that the A2Π - X2Σ+ transition is superior to B2Σ+ - X2Σ+ , where multiple tiny decay channels degrade its efficiency. Further possible improvements to the cooling method are proposed.

Equilibrium points of the tilted perfect fluid Bianchi VIh state space

NASA Astrophysics Data System (ADS)

Apostolopoulos, Pantelis S.

2005-05-01

We present the full set of evolution equations for the spatially homogeneous cosmologies of type VIh filled with a tilted perfect fluid and we provide the corresponding equilibrium points of the resulting dynamical state space. It is found that only when the group parameter satisfies h > -1 a self-similar solution exists. In particular we show that for h > -{1/9} there exists a self-similar equilibrium point provided that γ ∈ ({2(3+sqrt{-h})/5+3sqrt{-h}},{3/2}) whereas for h < -{frac 19} the state parameter belongs to the interval γ ∈(1,{2(3+sqrt{-h})/5+3sqrt{-h}}). This family of new exact self-similar solutions belongs to the subclass nαα = 0 having non-zero vorticity. In both cases the equilibrium points have a six-dimensional stable manifold and may act as future attractors at least for the models satisfying nαα = 0. Also we give the exact form of the self-similar metrics in terms of the state and group parameter. As an illustrative example we provide the explicit form of the corresponding self-similar radiation model (γ = {frac 43}), parametrised by the group parameter h. Finally we show that there are no tilted self-similar models of type III and irrotational models of type VIh.

Kaluza-Klein two-brane-worlds cosmology at low energy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feranie, S.; Arianto; Zen, Freddy P.

2010-04-15

We study two (4+n)-dimensional branes embedded in (5+n)-dimensional spacetime. Using the gradient expansion approximation, we find that the effective theory is described by (4+n)-dimensional scalar-tensor gravity with a specific coupling function. Based on this theory we investigate the Kaluza-Klein two-brane-worlds cosmology at low energy, in both the static and the nonstatic internal dimensions. In the case of the static internal dimensions, the effective gravitational constant in the induced Friedmann equation depends on the equations of state of the brane matter, and the dark radiation term naturally appears. In the nonstatic case we take a relation between the external and internalmore » scale factors of the form b(t)=a{sup {gamma}(t)} in which the brane world evolves with two scale factors. In this case, the induced Friedmann equation on the brane is modified in the effective gravitational constant and the term proportional to a{sup -4{beta}.} For dark radiation, we find {gamma}=-2/(1+n). Finally, we discuss the issue of conformal frames which naturally arises with scalar-tensor theories. We find that the static internal dimensions in the Jordan frame may become nonstatic in the Einstein frame.« less

PM-1 NUCLEAR POWER PROGRAM. VOLUME II. PLANT PERFORMANCE STUDIES. Final Periodic Report, September 1, 1962 to December 31, 1962

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

1963-04-01

Data obtained during the performance testing of the PM-1 plant were compiled and evaluated. The plant powers an Air Defense Command radar station located at Sundance, Wyoming, and is required to supply extremely high-quality electrical power (minimum of frequency and voltage fluctuations) even during severe load transients. The data obtained were compiled into the following format: (1) operating requirements; (2) startup requirements; (3) plant as an energy source; (4) plant radiation levels and health physics; (5) plant instrumentation and control; (6) reactor characteristics; (7) primary system characteristics; (8) secondary system characteristics; and (9) malfunction reports. It was concluded from themore » data that the plant performance in general meets or exceeds specification. Transient and steady-state electrical fluctuations are well within specified limitations. Heat balance data for both the primary and secondary system agree reasonably well with design predictions. Radiation levels are below those anticipated. Coolant activity in the primary system is approximately at anticipated levels; secondary system coolant activity is negligible. The core life was re-estimated based on asbuilt core characteristics. A lifetime of 16.6 Mw-yr is predicted. (auth)« less

LL13-MatModelRadDetect-PD2Jf Final Report: Materials Modeling for High-Performance Radiation Detectors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lordi, Vincenzo

The aims of this project are to enable rational materials design for select high-payoff challenges in radiation detection materials by using state-of-the-art predictive atomistic modeling techniques. Three specific high-impact challenges are addressed: (i) design and optimization of electrical contact stacks for TlBr detectors to stabilize temporal response at room-temperature; (ii) identification of chemical design principles of host glass materials for large-volume, low-cost, highperformance glass scintillators; and (iii) determination of the electrical impacts of dislocation networks in Cd 1-xZn xTe (CZT) that limit its performance and usable single-crystal volume. The specific goals are to establish design and process strategies to achievemore » improved materials for high performance detectors. Each of the major tasks is discussed below in three sections, which include the goals for the task and a summary of the major results, followed by a listing of publications that contain the full details, including details of the methodologies used. The appendix lists 12 conference presentations given for this project, including 1 invited talk and 1 invited poster.« less

Nonglobal correlations in collider physics

DOE PAGES

Moult, Ian; Larkoski, Andrew J.

2016-01-13

Despite their importance for precision QCD calculations, correlations between in- and out-of-jet regions of phase space have never directly been observed. These so-called non-global effects are present generically whenever a collider physics measurement is not explicitly dependent on radiation throughout the entire phase space. In this paper, we introduce a novel procedure based on mutual information, which allows us to isolate these non-global correlations between measurements made in different regions of phase space. We study this procedure both analytically and in Monte Carlo simulations in the context of observables measured on hadronic final states produced in e+e- collisions, though itmore » is more widely applicable.The procedure exploits the sensitivity of soft radiation at large angles to non-global correlations, and we calculate these correlations through next-to-leading logarithmic accuracy. The bulk of these non-global correlations are found to be described in Monte Carlo simulation. They increase by the inclusion of non-perturbative effects, which we show can be incorporated in our calculation through the use of a model shape function. As a result, this procedure illuminates the source of non-global correlations and has connections more broadly to fundamental quantities in quantum field theory.« less

Validation of the SINDA/FLUINT code using several analytical solutions

NASA Technical Reports Server (NTRS)

Keller, John R.

1995-01-01

The Systems Improved Numerical Differencing Analyzer and Fluid Integrator (SINDA/FLUINT) code has often been used to determine the transient and steady-state response of various thermal and fluid flow networks. While this code is an often used design and analysis tool, the validation of this program has been limited to a few simple studies. For the current study, the SINDA/FLUINT code was compared to four different analytical solutions. The thermal analyzer portion of the code (conduction and radiative heat transfer, SINDA portion) was first compared to two separate solutions. The first comparison examined a semi-infinite slab with a periodic surface temperature boundary condition. Next, a small, uniform temperature object (lumped capacitance) was allowed to radiate to a fixed temperature sink. The fluid portion of the code (FLUINT) was also compared to two different analytical solutions. The first study examined a tank filling process by an ideal gas in which there is both control volume work and heat transfer. The final comparison considered the flow in a pipe joining two infinite reservoirs of pressure. The results of all these studies showed that for the situations examined here, the SINDA/FLUINT code was able to match the results of the analytical solutions.

In situ studies of ion irradiated inverse spinel compound magnesium stannate (Mg 2SnO 4)

NASA Astrophysics Data System (ADS)

Xu, P.; Tang, M.; Nino, J. C.

2009-06-01

Magnesium stannate spinel (Mg 2SnO 4) was synthesized through conventional solid state processing and then irradiated with 1.0 MeV Kr 2+ ions at low temperatures 50 and 150 K. Structural evolutions during irradiation were monitored and recorded through bright field images and selected-area electron diffraction patterns using in situ transmission electron microscopy. The amorphization of Mg 2SnO 4 was achieved at an ion dose of 5 × 10 19 Kr ions/m 2 at 50 K and 10 20 Kr ions/m 2 at 150 K, which is equivalent to an atomic displacement damage of 5.5 and 11.0 dpa, respectively. The spinel crystal structure was thermally recovered at room temperature from the amorphous phase caused by irradiation at 50 K. The calculated electronic and nuclear stopping powers suggest that the radiation damage caused by 1 MeV Kr 2+ ions in Mg 2SnO 4 is mainly due to atomic displacement induced defect accumulation. The radiation tolerance of Mg 2SnO 4 was finally compared with normal spinel MgAl 2O 4.

Multi-time-scale heat transfer modeling of turbid tissues exposed to short-pulsed irradiations.

PubMed

Kim, Kyunghan; Guo, Zhixiong

2007-05-01

A combined hyperbolic radiation and conduction heat transfer model is developed to simulate multi-time-scale heat transfer in turbid tissues exposed to short-pulsed irradiations. An initial temperature response of a tissue to an ultrashort pulse irradiation is analyzed by the volume-average method in combination with the transient discrete ordinates method for modeling the ultrafast radiation heat transfer. This response is found to reach pseudo steady state within 1 ns for the considered tissues. The single pulse result is then utilized to obtain the temperature response to pulse train irradiation at the microsecond/millisecond time scales. After that, the temperature field is predicted by the hyperbolic heat conduction model which is solved by the MacCormack's scheme with error terms correction. Finally, the hyperbolic conduction is compared with the traditional parabolic heat diffusion model. It is found that the maximum local temperatures are larger in the hyperbolic prediction than the parabolic prediction. In the modeled dermis tissue, a 7% non-dimensional temperature increase is found. After about 10 thermal relaxation times, thermal waves fade away and the predictions between the hyperbolic and parabolic models are consistent.

Accretion dynamics and polarized X-ray emission of magnetized neutron stars

NASA Technical Reports Server (NTRS)

Arons, Jonathan

1991-01-01

The basic ideas of accretion onto magnetized neutron stars are outlined. These are applied to a simple model of the structure of the plasma mound sitting at the magnetic poles of such a star, in which upward diffusion of photons is balanced by their downward advection. This steady flow model of the plasma's dynamical state is used to compute the emission of polarized X-raysfrom the optically thick, birefringent medium. The linear polarization of the continuum radiation emerging from the quasi-static mound is found to be as much as 40 percent at some rotation phases, but is insensitive to the geometry of the accretion flow. The role of the accretion shock, whose detailed polarimetric and spectral characteristics have yet to be calculated, is emphasized as the final determinant of the properties of the emerging X-rays. Some results describing the fully time dependent dynamics of the flow are also presented. In particular, steady flow onto a neutron star is shown to exhibit formation of 'photon bubbles', regions of greatly reduced plasma density filled with radiation which form and rise on millisecond time scale. The possible role of these complex structures in the flow for the formation of the emergent spectrum is briefly outlined.

Medical Devices; General Hospital and Personal Use Devices; Classification of the Ultraviolet Radiation Chamber Disinfection Device. Final order.

PubMed

2015-11-20

The Food and Drug Administration (FDA or the Agency) is classifying the ultraviolet (UV) radiation chamber disinfection device into class II (special controls). The special controls that will apply to the device are identified in this order and will be part of the codified language for the UV radiation chamber disinfection device classification. The Agency is classifying the device into class II (special controls) in order to provide a reasonable assurance of safety and effectiveness of the device.

The Simulation of the Recharging Method Based on Solar Radiation for an Implantable Biosensor.

PubMed

Li, Yun; Song, Yong; Kong, Xianyue; Li, Maoyuan; Zhao, Yufei; Hao, Qun; Gao, Tianxin

2016-09-10

A method of recharging implantable biosensors based on solar radiation is proposed. Firstly, the models of the proposed method are developed. Secondly, the recharging processes based on solar radiation are simulated using Monte Carlo (MC) method and the energy distributions of sunlight within the different layers of human skin have been achieved and discussed. Finally, the simulation results are verified experimentally, which indicates that the proposed method will contribute to achieve a low-cost, convenient and safe method for recharging implantable biosensors.

The Simulation of the Recharging Method Based on Solar Radiation for an Implantable Biosensor

PubMed Central

Li, Yun; Song, Yong; Kong, Xianyue; Li, Maoyuan; Zhao, Yufei; Hao, Qun; Gao, Tianxin

2016-01-01

A method of recharging implantable biosensors based on solar radiation is proposed. Firstly, the models of the proposed method are developed. Secondly, the recharging processes based on solar radiation are simulated using Monte Carlo (MC) method and the energy distributions of sunlight within the different layers of human skin have been achieved and discussed. Finally, the simulation results are verified experimentally, which indicates that the proposed method will contribute to achieve a low-cost, convenient and safe method for recharging implantable biosensors. PMID:27626422

Cell specific radiation dosimetry in skeleton from life-span carcinogenesis studies. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Webster, S.S.J.

1993-04-05

The osteogenic sarcoma is the dominant life-threatening pathology in lifespan studies of beagles exposed to alpha-emitting bone-seeking radionuclides. It was deduced from these studies that certain skeletal sites are more prone to develop tumors. This project sought to determine the bone cells at risk and their cell-specific radiation dose. The cell-specific radiation dose values are related to loss and high Ra-226 and Pu-239 induced osteogenic sarcoma sites, to test different dose response hypothesis and predict the extent of effects in humans.

Diffraction radiation generators

NASA Astrophysics Data System (ADS)

Shestopalov, Viktor P.; Vertii, Aleksei A.; Ermak, Gennadii P.; Skrynnik, Boris K.; Khlopov, Grigorii I.; Tsvyk, Aleksei I.

Research in the field of diffraction radiation generators (DRG) conducted at the Radio Physics and electronics Institute of the Ukranian Academy of Sciences over the past 25 years is reviewed. The effect of diffraction radiation is analyzed in detail, and various operating regimes of DRGs are discussed. The discussion then focuses on the principal requirements for the design of packaged DRGs and their principal parameters. Finally, applications of DRGs in various fields of science and technology are reviewed, including such applications as DRG spectroscopy, diagnostics of plasma, biological specimens, and vibration, and DRG radar systems.

Biological effects of stellar collapse neutrinos

PubMed

Collar, J I

1996-02-05

Massive stars in their final stages of collapse radiate most of their binding energy in the form of MeV neutrinos. The recoil atoms that they produce in elastic scattering off nuclei in organic tissue create radiation damage which is highly effective in the production of irreparable DNA harm, leading to cellular mutation, neoplasia, and oncogenesis. Using a conventional model of the galaxy and of the collapse mechanism, the periodicity of nearby stellar collapses and the radiation dose are calculated. The possible contribution of this process to the paleontological record of mass extinctions is examined.

Radiation resistance of asporogenous bacteria in frozen beef. Final report, Sep 1974--Feb 1975

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maxcy, R.B.; Rowley, D.B.; Annellis, A.

1976-03-01

A scheme was developed to isolate the most radiation resistant vegetative microbial cells occurring in beef. Selection of pure cultures and enrichment provided 16 apparently different isolates with higher radiation resistance than spores of Clostridium botulinum. Most of these bacteria were found to be Moraxella or Acinetobacter. They grew over a temperature range of 2 - 50 C. Preliminary data indicated the isolates to be relatively sensitive to heat and to limited oxygen. It would appear these organisms are rather widespread and frequent in nature. (GRA)

First measurement of proton's charge form factor at very low Q2 with initial state radiation

NASA Astrophysics Data System (ADS)

Mihovilovič, M.; Weber, A. B.; Achenbach, P.; Beranek, T.; Beričič, J.; Bernauer, J. C.; Böhm, R.; Bosnar, D.; Cardinali, M.; Correa, L.; Debenjak, L.; Denig, A.; Distler, M. O.; Esser, A.; Ferretti Bondy, M. I.; Fonvieille, H.; Friedrich, J. M.; Friščić, I.; Griffioen, K.; Hoek, M.; Kegel, S.; Kohl, Y.; Merkel, H.; Middleton, D. G.; Müller, U.; Nungesser, L.; Pochodzalla, J.; Rohrbeck, M.; Sánchez Majos, S.; Schlimme, B. S.; Schoth, M.; Schulz, F.; Sfienti, C.; Širca, S.; Štajner, S.; Thiel, M.; Tyukin, A.; Vanderhaeghen, M.; Weinriefer, M.

2017-08-01

We report on a new experimental method based on initial-state radiation (ISR) in e-p scattering, which exploits the radiative tail of the elastic peak to study the properties of electromagnetic processes and to extract the proton charge form factor (GEp) at extremely small Q2. The ISR technique was implemented in an experiment at the three-spectrometer facility of the Mainz Microtron (MAMI). This led to a precise validation of radiative corrections far away from elastic line and provided first measurements of GEp for 0.001 ≤Q2 ≤ 0.004(GeV / c)2.

Assessment of two-temperature kinetic model for dissociating and weakly-ionizing nitrogen

NASA Technical Reports Server (NTRS)

Park, C.

1986-01-01

The validity of the author's two-temperature, chemical/kinetic model which the author has recently improved is assessed by comparing the calculated results with the existing experimental data for nitrogen in the dissociating and weakly ionizing regime produced behind a normal shock wave. The computer program Shock Tube Radiation Program (STRAP) based on the two-temperature model is used in calculating the flow properties behind the shock wave and the Nonequilibrium Air Radiation (NEQAIR) program, in determining the radiative characteristics of the flow. Both programs were developed earlier. Comparison is made between the calculated and the existing shock tube data on (1) spectra in the equilibrium region, (2) rotational temperature of the N2(+) B state, (3) vibrational temperature of the N2(+) B state, (4) electronic excitation temperature of the N2 B state, (5) the shape of time-variation of radiation intensities, (6) the times to reach the peak in radiation intensity and equilibrium, and (7) the ratio of nonequilibrium to equilibrium radiative heat fluxes. Good agreement is seen between the experimental data and the present calculation except for the vibrational temperature. A possible reason for the discrepancy is given.

Fast Atom Ionization in Strong Electromagnetic Radiation

NASA Astrophysics Data System (ADS)

Apostol, M.

2018-05-01

The Goeppert-Mayer and Kramers-Henneberger transformations are examined for bound charges placed in electromagnetic radiation in the non-relativistic approximation. The consistent inclusion of the interaction with the radiation field provides the time evolution of the wavefunction with both structural interaction (which ensures the bound state) and electromagnetic interaction. It is shown that in a short time after switching on the high-intensity radiation the bound charges are set free. In these conditions, a statistical criterion is used to estimate the rate of atom ionization. The results correspond to a sudden application of the electromagnetic interaction, in contrast with the well-known ionization probability obtained by quasi-classical tunneling through classically unavailable non-stationary states, or other equivalent methods, where the interaction is introduced adiabatically. For low-intensity radiation the charges oscillate and emit higher-order harmonics, the charge configuration is re-arranged and the process is resumed. Tunneling ionization may appear in these circumstances. Extension of the approach to other applications involving radiation-induced charge emission from bound states is discussed, like ionization of molecules, atomic clusters or proton emission from atomic nuclei. Also, results for a static electric field are included.

A VERSATILE FAMILY OF GALACTIC WIND MODELS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bustard, Chad; Zweibel, Ellen G.; D’Onghia, Elena, E-mail: bustard@wisc.edu

2016-03-01

We present a versatile family of model galactic outflows including non-uniform mass and energy source distributions, a gravitational potential from an extended mass source, and radiative losses. The model easily produces steady-state wind solutions for a range of mass-loading factors, energy-loading factors, galaxy mass, and galaxy radius. We find that, with radiative losses included, highly mass-loaded winds must be driven at high central temperatures, whereas low mass-loaded winds can be driven at low temperatures just above the peak of the cooling curve, meaning radiative losses can drastically affect the wind solution even for low mass-loading factors. By including radiative losses,more » we are able to show that subsonic flows can be ignored as a possible mechanism for expelling mass and energy from a galaxy compared to the more efficient transonic solutions. Specifically, the transonic solutions with low mass loading and high energy loading are the most efficient. Our model also produces low-temperature, high-velocity winds that could explain the prevalence of low-temperature material in observed outflows. Finally, we show that our model, unlike the well-known Chevalier and Clegg model, can reproduce the observed linear relationship between wind X-ray luminosity and star formation rate (SFR) over a large range of SFR from 1–1000 M{sub ⊙} yr{sup −1} assuming the wind mass-loading factor is higher for low-mass, and hence, low-SFR galaxies. We also constrain the allowed mass-loading factors that can fit the observed X-ray luminosity versus SFR trend, further suggesting an inverse relationship between mass loading and SFR as explored in advanced numerical simulations.« less

Stress and Burnout Among Residency Program Directors in United States Radiation Oncology Programs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aggarwal, Sonya; Kusano, Aaron S.; Carter, Justin Nathaniel

Purpose: To evaluate stressors among radiation oncology residency program directors (PDs) and determine the prevalence and indicators of burnout. Methods and Materials: An anonymous, online, cross-sectional survey was offered to PDs of US radiation oncology programs in the fall of 2014. Survey content examined individual and program demographics, perceptions surrounding the role of PD, and commonly encountered stressors. Burnout was assessed using the validated Maslach Burnout Inventory-Human Services Survey. Results: In total, 47 of 88 PDs (53%) responded to the survey. Although 78% of respondents reported feeling “satisfied” or “highly satisfied” with their current role, 85% planned to remain as PDmore » for <5 years. The most commonly cited stressors were satisfying Accreditation Council for Graduate Medical Education/Residency Review Committee requirements (47%), administrative duties (30%) and resident morale (28%). Three-quarters of respondents were satisfied that they became PDs. Overall, 11% of respondents met criteria for low burnout, 83% for moderate burnout, and 6% for high burnout. Not having served as a PD at a prior institution correlated with high depersonalization (OR 6.75, P=.04) and overall burnout (odds ratio [OR], 15.6; P=.04). Having more years on faculty prior to becoming PD correlated with less emotional exhaustion (OR, 0.44, P=.05) and depersonalization (OR, 0.20, P=.04). Finally, having dedicated time for PD duties correlated with less emotional exhaustion (OR, 0.27, P=.04). Conclusions: Moderate levels of burnout are common in U.S. radiation oncology PDs with regulatory stressors being common. Despite this, many PDs are fulfilled with their role. Longitudinal studies assessing dynamic external factors and their influence on PD burnout would be beneficial.« less

Heme oxygenase up-regulation under ultraviolet-B radiation is not epigenetically restricted and involves specific stress-related transcriptions factors.

PubMed

Santa-Cruz, Diego; Pacienza, Natalia; Zilli, Carla; Pagano, Eduardo; Balestrasse, Karina; Yannarelli, Gustavo

2017-08-01

Heme oxygenase-1 (HO-1) plays a protective role against oxidative stress in plants. The mechanisms regulating its expression, however, remain unclear. Here we studied the methylation state of a GC rich HO-1 promoter region and the expression of several stress-related transcription factors (TFs) in soybean plants subjected to ultraviolet-B (UV-B) radiation. Genomic DNA and total RNA were isolated from leaves of plants irradiated with 7.5 and 15kJm-2 UV-B. A 304bp HO-1 promoter region was amplified by PCR from sodium bisulfite-treated DNA, cloned into pGEMT plasmid vector and evaluated by DNA sequencing. Bisulfite sequencing analysis showed similar HO-1 promoter methylation levels in control and UV-B-treated plants (C: 3.4±1.3%; 7.5: 2.6±0.5%; 15: 3.1±1.1%). Interestingly, HO-1 promoter was strongly unmethylated in control plants. Quantitative RT-PCR analysis of TFs showed that GmMYB177, GmMYBJ6, GmWRKY21, GmNAC11, GmNAC20 and GmGT2A but not GmWRK13 and GmDREB were induced by UV-B radiation. The expression of several TFs was also enhanced by hemin, a potent and specific HO inducer, inferring that they may mediate HO-1 up-regulation. These results suggest that soybean HO-1 gene expression is not epigenetically regulated. Moreover, the low level of HO-1 promoter methylation suggests that this antioxidant enzyme can rapidly respond to environmental stress. Finally, this study has identified some stress-related TFs involved in HO-1 up-regulation under UV-B radiation. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Molecular spectrum of laterally coupled quantum rings under intense terahertz radiation.

PubMed

Baghramyan, Henrikh M; Barseghyan, Manuk G; Laroze, David

2017-09-05

We study the influence of intense THz laser radiation and electric field on molecular states of laterally coupled quantum rings. Laser radiation shows the capability to dissociate quantum ring molecule and add 2-fold degeneracy to the molecular states at the fixed value of the overlapping size between rings. It is shown that coupled to decoupled molecular states phase transition points form almost a straight line with a slope equal to two. In addition, the electric field direction dependent energy spectrum shows unexpected oscillations, demonstrating strong coupling between molecular states. Besides, intraband absorption is considered, showing both blue and redshifts in its spectrum. The obtained results can be useful for the controlling of degeneracy of the discrete energy spectrum of nanoscale structures and in the tunneling effects therein.

Controlling Directionality and Dimensionality of Radiation by Perturbing Separable Bound States in the Continuum

DOE PAGES

Rivera, Nicholas; Hsu, Chia Wei; Zhen, Bo; ...

2016-09-19

Here, a bound state in the continuum (BIC) is an unusual localized state that is embedded in a continuum of extended states. Here, we present the general condition for BICs to arise from wave equation separability. Then we show that by exploiting perturbations of certain symmetry such BICs can be turned into resonances that radiate with a tailorable directionality and dimensionality. Using this general framework, we construct new examples of separable BICs and resonances that can exist in optical potentials for ultracold atoms, photonic systems, and systems described by tight binding. Such resonances with easily reconfigurable radiation allow for applicationsmore » such as the storage and release of waves at a controllable rate and direction, as well systems that switch between different dimensions of confinement.« less

Puncture initial data for black-hole binaries with high spins and high boosts

NASA Astrophysics Data System (ADS)

Ruchlin, Ian; Healy, James; Lousto, Carlos O.; Zlochower, Yosef

2017-01-01

We solve the Hamiltonian and momentum constraints of general relativity for two black holes with nearly extremal spins and relativistic boosts in the puncture formalism. We use a non-conformally-flat ansatz with an attenuated superposition of two Lorentz-boosted, conformally Kerr or conformally Schwarzschild 3-metrics and their corresponding extrinsic curvatures. We compare evolutions of these data with the standard Bowen-York conformally flat ansatz (technically limited to intrinsic spins χ =S /MADM2=0.928 and boosts P /MADM=0.897 ), finding, typically, an order of magnitude smaller burst of spurious radiation and agreement with inspiral and merger. As a first case study, we evolve two equal-mass black holes from rest with an initial separation of d =12 M and spins χi=Si/mi2=0.99 , compute the waveforms produced by the collision, the energy and angular momentum radiated, and the recoil of the final remnant black hole. We find that the black-hole trajectories curve at close separations, leading to the radiation of angular momentum. We also study orbiting nonspinning and moderate-spin black-hole binaries and compare these with standard Bowen-York data. We find a substantial reduction in the nonphysical initial burst of radiation which leads to cleaner waveforms. Finally, we study the case of orbiting binary black-hole systems with spin magnitude χi=0.95 in an aligned configuration and compare waveform and final remnant results with those of the SXS Collaboration [54 A. H. Mroue et al., Phys. Rev. Lett. 111, 241104 (2013)., 10.1103/PhysRevLett.111.241104], finding excellent agreement. This represents the first moving puncture evolution of orbiting and spinning black holes exceeding the Bowen-York limit. Finally, we study different choices of the initial lapse and lapse evolution equation in the moving puncture approach to improve the accuracy and efficiency of the simulations.

A Fast Solver for Implicit Integration of the Vlasov--Poisson System in the Eulerian Framework

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garrett, C. Kristopher; Hauck, Cory D.

In this paper, we present a domain decomposition algorithm to accelerate the solution of Eulerian-type discretizations of the linear, steady-state Vlasov equation. The steady-state solver then forms a key component in the implementation of fully implicit or nearly fully implicit temporal integrators for the nonlinear Vlasov--Poisson system. The solver relies on a particular decomposition of phase space that enables the use of sweeping techniques commonly used in radiation transport applications. The original linear system for the phase space unknowns is then replaced by a smaller linear system involving only unknowns on the boundary between subdomains, which can then be solvedmore » efficiently with Krylov methods such as GMRES. Steady-state solves are combined to form an implicit Runge--Kutta time integrator, and the Vlasov equation is coupled self-consistently to the Poisson equation via a linearized procedure or a nonlinear fixed-point method for the electric field. Finally, numerical results for standard test problems demonstrate the efficiency of the domain decomposition approach when compared to the direct application of an iterative solver to the original linear system.« less

A Fast Solver for Implicit Integration of the Vlasov--Poisson System in the Eulerian Framework

DOE PAGES

Garrett, C. Kristopher; Hauck, Cory D.

2018-04-05

In this paper, we present a domain decomposition algorithm to accelerate the solution of Eulerian-type discretizations of the linear, steady-state Vlasov equation. The steady-state solver then forms a key component in the implementation of fully implicit or nearly fully implicit temporal integrators for the nonlinear Vlasov--Poisson system. The solver relies on a particular decomposition of phase space that enables the use of sweeping techniques commonly used in radiation transport applications. The original linear system for the phase space unknowns is then replaced by a smaller linear system involving only unknowns on the boundary between subdomains, which can then be solvedmore » efficiently with Krylov methods such as GMRES. Steady-state solves are combined to form an implicit Runge--Kutta time integrator, and the Vlasov equation is coupled self-consistently to the Poisson equation via a linearized procedure or a nonlinear fixed-point method for the electric field. Finally, numerical results for standard test problems demonstrate the efficiency of the domain decomposition approach when compared to the direct application of an iterative solver to the original linear system.« less

Radiation injury to the nervous system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gutin, P.H.; Leibel, S.A.; Sneline, G.E.

1991-01-01

This book is designed to describe to the radiation biologist, radiation oncologist, neurologist, neurosurgeon, medical oncologist, and neuro-oncologist, the current state of knowledge about the tolerance of the nervous system to various kinds of radiation, the mechanisms of radiation injury, and how nervous system tolerance and injury are related to the more general problem of radiation damage to normal tissue of all types. The information collected here should stimulate interest in and facilitate the growing research effort into radiation injury to the nervous system.

Radiation Effects on the Electrical Properties of MOS Device Materials.

DTIC Science & Technology

1978-02-01

3 Under Contract e ~i8 DAAG39~~ C.0O88 tJTtj~ J b This work _ sponsored by di. Ds~nse Nuclear Aisocy undur Nuclear ~ ffiupons Effucta flussarch...numb •r) Si02, MOS , CMOS Vacuum Ultraviolet Radiation Radiation Hardness Interfac e States Capture Cross Sections 2 ’ ~~’*~~ TRACT (Continu e on...When 0 t e Entered ) Results show that unannealed dry oxides have the lowest interface— state density after irrad iation, making them more desirable

Modeling and characterization of the Earth Radiation Budget Experiment (ERBE) nonscanner and scanner sensors

NASA Technical Reports Server (NTRS)

Halyo, Nesim; Pandey, Dhirendra K.; Taylor, Deborah B.

1989-01-01

The Earth Radiation Budget Experiment (ERBE) is making high-absolute-accuracy measurements of the reflected solar and Earth-emitted radiation as well as the incoming solar radiation from three satellites: ERBS, NOAA-9, and NOAA-10. Each satellite has four Earth-looking nonscanning radiometers and three scanning radiometers. A fifth nonscanner, the solar monitor, measures the incoming solar radiation. The development of the ERBE sensor characterization procedures are described using the calibration data for each of the Earth-looking nonscanners and scanners. Sensor models for the ERBE radiometers are developed including the radiative exchange, conductive heat flow, and electronics processing for transient and steady state conditions. The steady state models are used to interpret the sensor outputs, resulting in the data reduction algorithms for the ERBE instruments. Both ground calibration and flight calibration procedures are treated and analyzed. The ground and flight calibration coefficients for the data reduction algorithms are presented.

Observed Reduction In Surface Solar Radiation - Aerosol Forcing Versus Cloud Feedback?

NASA Astrophysics Data System (ADS)

Liepert, B.

The solar radiation reaching the ground is a key parameter for the climate system. It drives the hydrological cycle and numerous biological processes. Surface solar radi- ation revealed an estimated 7W/m2 or 4% decline at sites worldwide from 1961 to 1990. The strongest decline occurred at the United States sites with 19W/m2 or 10%. Increasing air pollution and hence direct and indirect aerosol effect, as we know today can only explain part of the reduction in solar radiation. Increasing cloud optical thick- ness - possibly due to global warming - is a more likely explanation for the observed reduction in solar radiation in the United States. The analysis of surface solar radiation data will be shown and compared with GCM results of the direct and indirect aerosol effect. It will be argued that the residual declines in surface solar radiation is likely due to cloud feedback.

Collision Processes in Methyl Chloride

NASA Astrophysics Data System (ADS)

Pape, Travis W.

Time-resolved, double resonance spectroscopy using infrared pump radiation and millimeter-wave and submillimeter -wave probe radiation (IRMMDR) has been used to study rotational and vibrational collision processes in CH_3 ^{35}Cl and CH_3 ^{37}Cl. A collisional energy transfer model using only five parameters for rotational processes plus those needed for vibrational processes accurately models over 500 IRMMDR time responses for 105 pump-probe combinations, using three pump coincidences and a wide range of probed rotational states. Previous studies in this laboratory revealed that J- and K-changing rotational energy transfer (RET) have vastly different characteristics in CH_3 F. As was found for CH_3F, J-changing rotational collision rates in CH_3 Cl are modeled accurately by both the Statistical Power Gap law and the Infinite Order Sudden approximation using a power law expression for the basis rates. However, in contrast to CH_3F, where all IRMMDR time responses for K-changing collisions have the same shape, many time responses of CH_3 Cl states populated by K-changing collisions contain an additional early-time feature (ETF) that varies with pump and probe state. Nonetheless, a simple generalization of the previously reported model for K-changing collisions is shown to account for all of the additional features observed in CH_3Cl. Rather than observing a fixed temperature for K-changing collisions as was the case for CH_3F, the temperature is found to be a function of time for CH_3 Cl. Moreover, the two new parameters this adds to the RET model are related to known physical quantities. A qualitative argument of K-changing collisions based on a classical picture is offered to explain the difference between the measured J- and K-changing state-to-state rates in CH_3Cl. As was observed in CH_3F, the principal vibrational collision processes are the near -resonant V-swap process, in which two colliding molecules exchange a quantum of vibrational energy, and a nonresonant process that directly moves population from the pumped {bf v}_6 = 1 vibrational state to the {bf v}_3 = 1 vibrational state. A V to T/R process was also measured. Finally, a V-swap process was measured that populates vibrational states of the other isotopic species.

Solid-state radiation-emitting compositions and devices

DOEpatents

Ashley, Carol S.; Brinker, C. Jeffrey; Reed, Scott; Walko, Robert J.

1992-01-01

The invention relates to a composition for the volumetric generation of radiation, wherein a first substance functions as a source of exciting radiation, and a second substance interacts with the exciting radiation to provide a second radiation. The compositions comprise a porous substrate which is loaded with: a source of exciting radiation, a component capable of emitting radiation upon interaction with the exciting radiation, or both. Preferably, the composition is an aerogel substrate loaded with both a source of exciting radiation, such as tritium, and a component capable of interacting with the exciting radiation, e.g., a phosphor, to produce radiation of a second energy.

Solid-state radiation-emitting compositions and devices

DOEpatents

Ashley, C.S.; Brinker, C.J.; Reed, S.; Walko, R.J.

1992-08-11

The invention relates to a composition for the volumetric generation of radiation, wherein a first substance functions as a source of exciting radiation, and a second substance interacts with the exciting radiation to provide a second radiation. The compositions comprise a porous substrate which is loaded with: a source of exciting radiation, a component capable of emitting radiation upon interaction with the exciting radiation, or both. Preferably, the composition is an aerogel substrate loaded with both a source of exciting radiation, such as tritium, and a component capable of interacting with the exciting radiation, e.g., a phosphor, to produce radiation of a second energy. 4 figs.

1985 Annual Conference on Nuclear and Space Radiation Effects, 22nd, Monterey, CA, July 22-24, 1985, Proceedings

NASA Technical Reports Server (NTRS)

Jones, C. W. (Editor)

1985-01-01

Basic mechanisms of radiation effects in structures and materials are discussed, taking into account the time dependence of interface state production, process dependent build-up of interface states in irradiated N-channel MOSFETs, bias annealing of radiation and bias induced positive charges in n- and p-type MOS capacitors, hole removal in thin-gate MOSFETs by tunneling, and activation energies of oxide charge recovery in SOS or SOI structures after an ionizing pulse. Other topics investigated are related to radiation effects in devices, radiation effects in integrated circuits, spacecraft charging and space radiation effects, single-event phenomena, hardness assurance and radiation sources, SGEMP/IEMP phenomena, EMP phenomena, and dosimetry and energy-dependent effects. Attention is given to a model of the plasma wake generated by a large object, gate charge collection and induced drain current in GaAs FETs, simulation of charge collection in a multilayer device, and time dependent dose enhancement effects on integrated circuit transient response mechanisms.

1985 Annual Conference on Nuclear and Space Radiation Effects, 22nd, Monterey, CA, July 22-24, 1985, Proceedings

NASA Astrophysics Data System (ADS)

Jones, C. W.

1985-12-01

Basic mechanisms of radiation effects in structures and materials are discussed, taking into account the time dependence of interface state production, process dependent build-up of interface states in irradiated N-channel MOSFETs, bias annealing of radiation and bias induced positive charges in n- and p-type MOS capacitors, hole removal in thin-gate MOSFETs by tunneling, and activation energies of oxide charge recovery in SOS or SOI structures after an ionizing pulse. Other topics investigated are related to radiation effects in devices, radiation effects in integrated circuits, spacecraft charging and space radiation effects, single-event phenomena, hardness assurance and radiation sources, SGEMP/IEMP phenomena, EMP phenomena, and dosimetry and energy-dependent effects. Attention is given to a model of the plasma wake generated by a large object, gate charge collection and induced drain current in GaAs FETs, simulation of charge collection in a multilayer device, and time dependent dose enhancement effects on integrated circuit transient response mechanisms.

Using ISCCP Weather States to Decompose Cloud Radiative Effects

NASA Technical Reports Server (NTRS)

Oreopoulos, L.; Rossow, W. B.

2012-01-01

The presentation will examine the shortwave (SW) and longwave (LW) cloud radiative effect CRE (aka "cloud radiative forcing") at the top-of-the-atmosphere and surface of ISCCP weather states (aka "cloud regimes") in three distinct geographical zones, one tropical and two mid-latitude. Our goal is to understand and quantify the contribution of the different cloud regimes to the planetary radiation budget. In the tropics we find that the three most convectively active states are the ones with largest SW, LW and net TOA CRE contributions to the overall daytime tropical CRE budget. They account for 59%, 71% and 55% of the total CRE, respectively. The boundary layer-dominated weather states account for only 34% of the total SW CRE and 41% of the total net CRE, so to focus only on them in cloud feedback studies may be imprudent. We also find that in both the northern and southern midlatitude zones only two weather states, the first and third most convectively active with large amounts of nimbostratus-type clouds, contribute ",40% to both the SW and net TOA CRE budgets, highlighting the fact that cloud regimes associated with frontal systems are not only important for weather (precipitation) but also for climate (radiation budget). While all cloud regimes in all geographical zones have a slightly larger SFC than TOA SW CRE, implying cooling of the surface and slight warming of the atmosphere, their LW radiative effects are more subtle: in the tropics the weather states with plentiful high clouds warm the atmosphere while those with copious amounts of low clouds cool the atmosphere. In both midlatitude zones only the weather states with peak cloud fractions at levels above 440 mbar warm the atmosphere while all the rest cool it. These results make the connection of the contrasting CRE effects to the atmospheric dynamics more explicit - "storms" tend to warm the atmosphere whereas fair weather clouds cool it, suggesting a positive feedback of clouds on weather systems. The breakdown of CRE by cloud regime are however not entirely similar between the two midlatitude zones. Despite the existence of an additional state in the nort!lern midlatitudes, only four weather states have net daytime CREs with absolute values above 100 Watts per square meter compared to six in the south. This reminds us that the environment where clouds occur also has a crucial role in determining their radiative effects. All the above make evident that reproducing grand averages of current CRE by climate models in only part of the challenge. If existing cloud regimes and shifts in their distributions and frequency of occurrence in a changed climate are not properly simulated, the radiative role of clouds will not be adequately predicted.

Select strengths and biases of models in representing the Arctic winter boundary layer over sea ice: the Larcform 1 single column model intercomparison

NASA Astrophysics Data System (ADS)

Pithan, Felix; Ackerman, Andrew; Angevine, Wayne M.; Hartung, Kerstin; Ickes, Luisa; Kelley, Maxwell; Medeiros, Brian; Sandu, Irina; Steeneveld, Gert-Jan; Sterk, H. A. M.; Svensson, Gunilla; Vaillancourt, Paul A.; Zadra, Ayrton

2016-09-01

Weather and climate models struggle to represent lower tropospheric temperature and moisture profiles and surface fluxes in Arctic winter, partly because they lack or misrepresent physical processes that are specific to high latitudes. Observations have revealed two preferred states of the Arctic winter boundary layer. In the cloudy state, cloud liquid water limits surface radiative cooling, and temperature inversions are weak and elevated. In the radiatively clear state, strong surface radiative cooling leads to the build-up of surface-based temperature inversions. Many large-scale models lack the cloudy state, and some substantially underestimate inversion strength in the clear state. Here, the transformation from a moist to a cold dry air mass is modeled using an idealized Lagrangian perspective. The trajectory includes both boundary layer states, and the single-column experiment is the first Lagrangian Arctic air formation experiment (Larcform 1) organized within GEWEX GASS (Global atmospheric system studies). The intercomparison reproduces the typical biases of large-scale models: some models lack the cloudy state of the boundary layer due to the representation of mixed-phase microphysics or to the interaction between micro- and macrophysics. In some models, high emissivities of ice clouds or the lack of an insulating snow layer prevent the build-up of surface-based inversions in the radiatively clear state. Models substantially disagree on the amount of cloud liquid water in the cloudy state and on turbulent heat fluxes under clear skies. Observations of air mass transformations including both boundary layer states would allow for a tighter constraint of model behavior.

American Society for Radiation Oncology (ASTRO) Survey of Radiation Biology Educators in U.S. and Canadian Radiation Oncology Residency Programs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rosenstein, Barry S., E-mail: barry.rosenstein@mssm.ed; Department of Radiation Oncology, New York University School of Medicine, New York, NY; Held, Kathryn D.

2009-11-01

Purpose: To obtain, in a survey-based study, detailed information on the faculty currently responsible for teaching radiation biology courses to radiation oncology residents in the United States and Canada. Methods and Materials: In March-December 2007 a survey questionnaire was sent to faculty having primary responsibility for teaching radiation biology to residents in 93 radiation oncology residency programs in the United States and Canada. Results: The responses to this survey document the aging of the faculty who have primary responsibility for teaching radiation biology to radiation oncology residents. The survey found a dramatic decline with time in the percentage of educatorsmore » whose graduate training was in radiation biology. A significant number of the educators responsible for teaching radiation biology were not fully acquainted with the radiation sciences, either through training or practical application. In addition, many were unfamiliar with some of the organizations setting policies and requirements for resident education. Freely available tools, such as the American Society for Radiation Oncology (ASTRO) Radiation and Cancer Biology Practice Examination and Study Guides, were widely used by residents and educators. Consolidation of resident courses or use of a national radiation biology review course was viewed as unlikely by most programs. Conclusions: A high priority should be given to the development of comprehensive teaching tools to assist those individuals who have responsibility for teaching radiation biology courses but who do not have an extensive background in critical areas of radiobiology related to radiation oncology. These findings also suggest a need for new graduate programs in radiobiology.« less

A brief introduction to PYTHIA 8.1

NASA Astrophysics Data System (ADS)

Sjöstrand, Torbjörn; Mrenna, Stephen; Skands, Peter

2008-06-01

The PYTHIA program is a standard tool for the generation of high-energy collisions, comprising a coherent set of physics models for the evolution from a few-body hard process to a complex multihadronic final state. It contains a library of hard processes and models for initial- and final-state parton showers, multiple parton-parton interactions, beam remnants, string fragmentation and particle decays. It also has a set of utilities and interfaces to external programs. While previous versions were written in Fortran, PYTHIA 8 represents a complete rewrite in C++. The current release is the first main one after this transition, and does not yet in every respect replace the old code. It does contain some new physics aspects, on the other hand, that should make it an attractive option especially for LHC physics studies. Program summaryProgram title:PYTHIA 8.1 Catalogue identifier: ACTU_v3_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ACTU_v3_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: GPL version 2 No. of lines in distributed program, including test data, etc.: 176 981 No. of bytes in distributed program, including test data, etc.: 2 411 876 Distribution format: tar.gz Programming language: C++ Computer: Commodity PCs Operating system: Linux; should also work on other systems RAM: 8 megabytes Classification: 11.2 Does the new version supersede the previous version?: yes, partly Nature of problem: High-energy collisions between elementary particles normally give rise to complex final states, with large multiplicities of hadrons, leptons, photons and neutrinos. The relation between these final states and the underlying physics description is not a simple one, for two main reasons. Firstly, we do not even in principle have a complete understanding of the physics. Secondly, any analytical approach is made intractable by the large multiplicities. Solution method: Complete events are generated by Monte Carlo methods. The complexity is mastered by a subdivision of the full problem into a set of simpler separate tasks. All main aspects of the events are simulated, such as hard-process selection, initial- and final-state radiation, beam remnants, fragmentation, decays, and so on. Therefore events should be directly comparable with experimentally observable ones. The programs can be used to extract physics from comparisons with existing data, or to study physics at future experiments. Reasons for new version: Improved and expanded physics models, transition from Fortran to C++. Summary of revisions: New user interface, transverse-momentum-ordered showers, interleaving with multiple interactions, and much more. Restrictions: Depends on the problem studied. Running time: 10-1000 events per second, depending on process studied. References: [1] T. Sjöstrand, P. Edén, C. Friberg, L. Lönnblad, G. Miu, S. Mrenna, E. Norrbin, Comput. Phys. Comm. 135 (2001) 238.

Total-dose radiation effects data for semiconductor devices. 1985 supplement. Volume 2, part A

NASA Technical Reports Server (NTRS)

Martin, K. E.; Gauthier, M. K.; Coss, J. R.; Dantas, A. R. V.; Price, W. E.

1986-01-01

Steady-state, total-dose radiation test data, are provided in graphic format for use by electronic designers and other personnel using semiconductor devices in a radiation environment. The data were generated by JPL for various NASA space programs. This volume provides data on integrated circuits. The data are presented in graphic, tabular, and/or narrative format, depending on the complexity of the integrated circuit. Most tests were done using the JPL or Boeing electron accelerator (Dynamitron) which provides a steady-state 2.5 MeV electron beam. However, some radiation exposures were made with a Cobalt-60 gamma ray source, the results of which should be regarded as only an approximate measure of the radiation damage that would be incurred by an equivalent electron dose.

Infrared radiative decay dynamics from the γ 1u (3P2), H 1u (3P1), and 1u (1D2) ion-pair states of I2 observed by a perturbation facilitated optical-optical double resonance technique

NASA Astrophysics Data System (ADS)

Hoshino, Shoma; Araki, Mitsunori; Nakano, Yukio; Ishiwata, Takashi; Tsukiyama, Koichi

2016-01-01

We report the spectroscopic and temporal analyses on the amplified spontaneous emission (ASE) from the single rovibrational levels of the Ω = 1u ion-pair series, γ 1u (3P2), H 1u (3P1), and 1u (1D2), of I2 by using a perturbation facilitated optical-optical double resonance technique through the c 1 Π g ˜ B 3 Π ( 0u + ) hyperfine mixed valence state as the intermediate state. The ASE detected in the infrared region was assigned to the parallel transitions from the Ω = 1u ion-pair states down to the nearby Ω = 1g ion-pair states. The subsequent ultraviolet (UV) fluorescence from the Ω = 1g states was also observed and the relative vibrational populations in the Ω = 1g states were derived through the Franck-Condon simulation of the intensity pattern of the vibrational progression. In the temporal profiles of the UV fluorescence, an obvious delay in the onset of the fluorescence was recognized after the excitation laser pulse. These results revealed that ASE is a dominant energy relaxation process between the Ω = 1u and 1g ion-pair states of I2. Finally, the lifetimes of the relevant ion-pair states were evaluated by temporal analyses of the UV fluorescence. The propensity was found which was the longer lifetime in the upper level of the ASE transitions tends to give intense ASE.

Crop Yield Simulations Using Multiple Regional Climate Models in the Southwestern United States

NASA Astrophysics Data System (ADS)

Stack, D.; Kafatos, M.; Kim, S.; Kim, J.; Walko, R. L.

2013-12-01

Agricultural productivity (described by crop yield) is strongly dependent on climate conditions determined by meteorological parameters (e.g., temperature, rainfall, and solar radiation). California is the largest producer of agricultural products in the United States, but crops in associated arid and semi-arid regions live near their physiological limits (e.g., in hot summer conditions with little precipitation). Thus, accurate climate data are essential in assessing the impact of climate variability on agricultural productivity in the Southwestern United States and other arid regions. To address this issue, we produced simulated climate datasets and used them as input for the crop production model. For climate data, we employed two different regional climate models (WRF and OLAM) using a fine-resolution (8km) grid. Performances of the two different models are evaluated in a fine-resolution regional climate hindcast experiment for 10 years from 2001 to 2010 by comparing them to the North American Regional Reanalysis (NARR) dataset. Based on this comparison, multi-model ensembles with variable weighting are used to alleviate model bias and improve the accuracy of crop model productivity over large geographic regions (county and state). Finally, by using a specific crop-yield simulation model (APSIM) in conjunction with meteorological forcings from the multi-regional climate model ensemble, we demonstrate the degree to which maize yields are sensitive to the regional climate in the Southwestern United States.

On the detection of a stochastic background of gravitational radiation by the Doppler tracking of spacecraft

NASA Technical Reports Server (NTRS)

Mashhoon, B.; Grishchuk, L. P.

1980-01-01

Consideration is given to the possibility of detection of an isotropic background gravitational radiation of a stochastic nature by the method of Doppler tracking of spacecraft. Attention is given in the geometrical optics limit, to the general formula for the frequency shift of an electromagnetic signal in the gravitational radiation field, and it is shown to be gauge independent. The propagation of a free electromagnetic wave in a gravitational radiation field is examined with the conclusion that no resonance phenomena can be expected. Finally, the 'Doppler noise' due to a stochastic background is evaluated, and it is shown to depend on the total energy density of the background and a parameter that is a characteristic of the radiation spectrum and the detection system used.

Radiation testing campaign results for understanding the suitability of FPGAs in detector electronics

DOE PAGES

Citterio, M.; Camplani, A.; Cannon, M.; ...

2015-11-19

SRAM based Field Programmable Gate Arrays (FPGAs) have been rarely used in High Energy Physics (HEP) due to their sensitivity to radiation. The last generation of commercial FPGAs based on 28 nm feature size and on Silicon On Insulator (SOI) technologies are more tolerant to radiation to the level that their use in front-end electronics is now feasible. FPGAs provide re-programmability, high-speed computation and fast data transmission through the embedded serial transceivers. They could replace custom application specific integrated circuits in front end electronics in locations with moderate radiation field. Finally, the use of a FPGA in HEP experiments ismore » only limited by our ability to mitigate single event effects induced by the high energy hadrons present in the radiation field.« less

Inhibition of trihalomethane formation in city water by radiation-ozone treatment and rapid composting of radiation disinfected sewage sludge

NASA Astrophysics Data System (ADS)

Takehisa, M.; Arai, H.; Arai, M.; Miyata, T.; Sakumoto, A.; Hashimoto, S.; Nishimura, K.; Watanabe, H.; Kawakami, W.; Kuriyama, I.

Humic acid and Fulvic acid in natural water are precursors of carcinogenic THM which is formed during chlorine disinfection in city water processing. The radiation-oxidation process in the presence of ozone is effective to remove the precursors. The THM formation was reduced more than the decrease in TOC by the combination treatment. This is mainly due to a change in the chemical structure of the oxidation products. A composting of radiation disinfected sludge cake for agricultural reuse could be achieved within 3 days primary fermentation in a sewage plant. The rapid fermentation with use of radiation is effective to scale down of a fermentor of composting plant and the process reduces a health risk from the workers as well as final users.

Epigenomic Adaptation to Low Dose Radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gould, Michael N.

2015-06-30

The overall hypothesis of this grant application is that the adaptive responses elicited by low dose ionizing radiation (LDIR) result in part from heritable DNA methylation changes in the epigenome. In the final budget period at the University of Wisconsin-Madison, we will specifically address this hypothesis by determining if the epigenetically labile, differentially methylated regions (DMRs) that regulate parental-specific expression of imprinted genes are deregulated in agouti mice by low dose radiation exposure during gestation. This information is particularly important to ascertain given the 1) increased human exposure to medical sources of radiation; 2) increased number of people predicted tomore » live and work in space; and 3) enhanced citizen concern about radiation exposure from nuclear power plant accidents and terrorist ‘dirty bombs.’« less

Recommendations for Nuclear Medicine Technologists Drawn from an Analysis of Errors Reported in Australian Radiation Incident Registers.

PubMed

Kearney, Nicole; Denham, Gary

2016-12-01

When a radiation incident occurs in nuclear medicine in Australia, the incident is reported to the relevant state or territory authority, which performs an investigation and sends its findings to the Australian Radiation Protection and Nuclear Safety Agency. The agency then includes these data in its Australian Radiation Incident Register and makes them available to the public as an annual summary report on its website. The aim of this study was to analyze the radiation incidents included in these annual reports and in the publically available state and territory registers, identify any recurring themes, and make recommendations to minimize future incidents. A multidisciplinary team comprising a nuclear medicine technologist, a radiation therapist, and a diagnostic radiographer analyzed all nuclear medicine technology-, radiation therapy-, and diagnostic radiography-related incidents recorded in the Australian Radiation Incident Register and in the registers of New South Wales, Western Australia, Victoria, South Australia, and Tasmania between 2003 and 2015. Each incident was placed into 1 of 18 categories, and each category was examined to determine any recurring causes of the incidents. We analyzed 209 nuclear medicine incidents. Their primary cause was failure to comply with time-out protocols (85.6%). By analyzing both the causes and the rates of radiation incidents, we were able to recommend ways to help prevent them from being repeated. Information drawn from the Australian Radiation Incident Register and 5 state registers has revealed steps that can be taken by any nuclear medicine department to prevent repetition of the incidents that have already occurred. © 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.