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Note: This page contains sample records for the topic "ray 202-586-5077 tosha" from the National Library of EnergyBeta (NLEBeta).
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1

?-ray astronomy  

Science Journals Connector (OSTI)

... THE title on the cover of this book reads Gamma-Ray Astronomy but inside a subtitle, Nuclear Transition Region has been added. This uncertainty as to ... an uneven quality to what is, otherwise, a valuable contribution to this field of astronomy.

R. R. Hillier

1977-05-26T23:59:59.000Z

2

Gamma Ray Bursts  

E-Print Network (OSTI)

Olson. Observations of gamma-ray bursts of cosmic origin. E. Lingenfelter. Gamma-ray bursts. Annual Review of652-654. Waxman, Eli. Gamma-ray-burst afterglow: supporting

Stahl, Bennett

2014-01-01T23:59:59.000Z

3

Gammaray bursts  

Science Journals Connector (OSTI)

...R. Priest and N. O. Weiss Gamma-ray bursts Martin J. Rees Institute of...Road, Cambridge CB3 0HA, UK Gamma-ray bursts, an enigma for more than 25...gamma-rays|neutron stars| Gamma-ray bursts By Martin J. Rees Institute...

2000-01-01T23:59:59.000Z

4

Gamma ray burst positrons  

Science Journals Connector (OSTI)

The international network of gamma ray burst detectors has provided redundant localizations for six gamma ray bursts with accuracies in the arcminute range. Catalog radio soft X?ray and optical searches have been performed for some of these events. The results of these searches are reviewed. Although radio X?ray and optical candidates are found in the error boxes no clear association between gamma ray bursts and other forms of emission has emerged to date. Optical radio searches are continuing.

K. Hurley

1982-01-01T23:59:59.000Z

5

Gamma ray generator  

DOE Patents (OSTI)

An embodiment of a gamma ray generator includes a neutron generator and a moderator. The moderator is coupled to the neutron generator. The moderator includes a neutron capture material. In operation, the neutron generator produces neutrons and the neutron capture material captures at least some of the neutrons to produces gamma rays. An application of the gamma ray generator is as a source of gamma rays for calibration of gamma ray detectors.

Firestone, Richard B; Reijonen, Jani

2014-05-27T23:59:59.000Z

6

24. Cosmic rays 1 24. COSMIC RAYS  

E-Print Network (OSTI)

electrons, protons and helium, as well as carbon, oxygen, iron, and other nuclei synthesized in stars) and the intensity of the cosmic rays with energies below about 10 GeV. In addition, the lower-energy cosmic rays the intensity of any component of the cosmic radiation in the GeV range depends both on the location and time

7

26. Cosmic rays 1 26. COSMIC RAYS  

E-Print Network (OSTI)

electrons, protons and helium, as well as carbon, oxygen, iron, and other nuclei synthesized in stars) and the intensity of the cosmic rays with energies below about 10 GeV. In addition, the lower-energy cosmic rays the intensity of any component of the cosmic radiation in the GeV range depends both on the location and time

8

HAWC ?-Ray Observatory  

NLE Websites -- All DOE Office Websites (Extended Search)

(HAWC) Gamma Ray Observatory formally began operations. HAWC is designed to study the origin of very high-energy cosmic rays and observe the most energetic objects in the known...

9

Ray J. Corey- Biography  

Energy.gov (U.S. Department of Energy (DOE))

Ray Corey currently serves as the Assistance Manager for Safety and Environment at the DOE Richland Operations office (RL).

10

Gamma-ray Astronomy  

E-Print Network (OSTI)

The relevance of gamma-ray astronomy to the search for the origin of the galactic and, to a lesser extent, the ultra-high-energy cosmic rays has long been recognised. The current renaissance in the TeV gamma-ray field has resulted in a wealth of new data on galactic and extragalactic particle accelerators, and almost all the new results in this field were presented at the recent International Cosmic Ray Conference (ICRC). Here I summarise the 175 papers submitted on the topic of gamma-ray astronomy to the 30th ICRC in Merida, Mexico in July 2007.

Jim Hinton

2007-12-20T23:59:59.000Z

11

Parallel Seismic Ray Tracing  

E-Print Network (OSTI)

. . . . . . . . . . . . . . . . . . . . . 27 3.4.1 Rotated Take-Off Angle Mesh . . . . . . . . . . . . . . . . . . 28 3.4.2 Rotated Cubed Sphere Mesh . . . . . . . . . . . . . . . . . . . 29 3.4.3 Ray Tube Interpolation . . . . . . . . . . . . . . . . . . . . . . 30 3.5 Theoretical Model..., the ray parameters are defined as ?1 = ?(declination), ?2 = ?(azimuth), and ?3 = ?(travel-time). (b) Suppose we have a unit cube centered at the source point, then a ray can be traced from the source point through an evenly discretized point on the face...

Jain, Tarun K

2013-12-09T23:59:59.000Z

12

Cosmic Ray Astronomy  

E-Print Network (OSTI)

Cosmic ray astronomy attempts to identify and study the sources of ultrahigh energy cosmic rays. It is unique in its reliance on charged particles as the information carriers. While no discrete source of ultrahigh energy cosmic rays has been identified so far, a new generation of detectors is acquiring the huge exposure that is needed at the highest energies, where deflection by magnetic fields is minimized and the background from distant sources is eliminated by pion photoproduction. In this paper, we summarize the status of cosmic ray astronomy, describing the detectors and the analysis techniques.

Paul Sommers; Stefan Westerhoff

2008-02-09T23:59:59.000Z

13

Gamma Ray Bursts Sudden, intense flashes of gamma rays  

E-Print Network (OSTI)

Gamma Ray Bursts #12;The Case Sudden, intense flashes of gamma rays come from nowhere and disappear with out a trace. Incredibly powerful: A single gamma ray burst is hundreds of times brighter a supernova #12;Who Vela (1960's) Looking for arms testing, found gamma ray bursts Compton Gamma Ray Observatory

Washington at Seattle, University of - Department of Physics, Electroweak Interaction Research Group

14

Gamma Ray Bursts  

E-Print Network (OSTI)

Gamma-ray bursts have been detected at photon energies up to tens of GeV. We review some recent developments in the X-ray to GeV photon phenomenology in the light of Swift and Fermi observations, and some of the theoretical models developed to explain them, with a view towards implications for C.T.A.

Peter Mszros

2012-04-12T23:59:59.000Z

15

Chest x-Rays  

Energy.gov (U.S. Department of Energy (DOE))

The B-reading is a special reading of a standard chest x-ray film performed by a physician certified by the National Institute for Occupational Safety and Health (NIOSH). The reading looks for changes on the chest x-ray that may indicate exposure and disease caused by agents such as asbestos or silica.

16

Gamma ray bursts  

Science Journals Connector (OSTI)

The time histories size spectrum spatial distribution and repetition rates of gamma ray bursts are reviewed briefly. Evidence for a neutron star origin for gamma ray bursts may be found in many of these aspects of bursters. New results from optical searches are described. Substantial progress has been made recently in the optical identificaiton of the 1978 November 19 burst.

K. Hurley

1983-01-01T23:59:59.000Z

17

X-ray beamsplitter  

DOE Patents (OSTI)

An x-ray beamsplitter which splits an x-ray beam into two coherent parts by reflecting and transmitting some fraction of an incident beam has applications for x-ray interferometry, x-ray holography, x-ray beam manipulation, and x-ray laser cavity output couplers. The beamsplitter is formed of a wavelength selective multilayer thin film supported by a very thin x-ray transparent membrane. The beamsplitter resonantly transmits and reflects x-rays through thin film interference effects. A thin film is formed of 5--50 pairs of alternate Mo/Si layers with a period of 20--250 A. The support membrane is 10--200 nm of silicon nitride or boron nitride. The multilayer/support membrane structure is formed across a window in a substrate by first forming the structure on a solid substrate and then forming a window in the substrate to leave a free-standing structure over the window. 6 figs.

Ceglio, N.M.; Stearns, D.G.; Hawryluk, A.M.; Barbee, T.W. Jr.

1987-08-07T23:59:59.000Z

18

X-ray beamsplitter  

DOE Patents (OSTI)

An x-ray beamsplitter which splits an x-ray beam into two coherent parts by reflecting and transmitting some fraction of an incident beam has applications for x-ray interferometry, x-ray holography, x-ray beam manipulation, and x-ray laser cavity output couplers. The beamsplitter is formed of a wavelength selective multilayer thin film supported by a very thin x-ray transparent membrane. The beamsplitter resonantly transmits and reflects x-rays through thin film interference effects. A thin film is formed of 5-50 pairs of alternate Mo/Si layers with a period of 20-250 A. The support membrane is 10-200 nm of silicon nitride or boron nitride. The multilayer/support membrane structure is formed across a window in a substrate by first forming the structure on a solid substrate and then forming a window in the substrate to leave a free-standing structure over the window.

Ceglio, Natale M. (Livermore, CA); Stearns, Daniel S. (Mountain View, CA); Hawryluk, Andrew M. (Modesto, CA); Barbee, Jr., Troy W. (Palo Alto, CA)

1989-01-01T23:59:59.000Z

19

X-ray binaries  

E-Print Network (OSTI)

We review the nuclear astrophysics aspects of accreting neutron stars in X-ray binaries. We summarize open astrophysical questions in light of recent observations and their relation to the underlying nuclear physics. Recent progress in the understanding of the nuclear physics, especially of X-ray bursts, is also discussed.

H. Schatz; K. E. Rehm

2006-08-01T23:59:59.000Z

20

Gamma-ray binaries  

E-Print Network (OSTI)

Recent observations have shown that some compact stellar binaries radiate the highest energy light in the universe. The challenge has been to determine the nature of the compact object and whether the very high energy gamma-rays are ultimately powered by pulsar winds or relativistic jets. Multiwavelength observations have shown that one of the three gamma-ray binaries known so far, PSR B1259-63, is a neutron star binary and that the very energetic gamma-rays from this source and from another gamma-ray binary, LS I +61 303, may be produced by the interaction of pulsar winds with the wind from the companion star. At this time it is an open question whether the third gamma-ray binary, LS 5039, is also powered by a pulsar wind or a microquasar jet, where relativistic particles in collimated jets would boost the energy of the wind from the stellar companion to TeV energies.

I. F. Mirabel

2006-10-24T23:59:59.000Z

Note: This page contains sample records for the topic "ray 202-586-5077 tosha" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Mono-Energetic Gamma-ray (MEGa-ray)  

NLE Websites -- All DOE Office Websites (Extended Search)

(MeV) spectral range. MEGa-ray Rendering In the mono-energetic gamma-ray (MEGA-ray) device, electrons and laser photons crash head-on, creating a backscatter of gamma...

22

X-ray absorption spectroscopy  

E-Print Network (OSTI)

009-9473-8 REVIEW X-ray absorption spectroscopy Junko Yano and application of X-ray absorption spectroscopy, bothX-ray absorption near-edge structure (XANES) and extended X-

Yano, Junko; Yachandra, Vittal K.

2009-01-01T23:59:59.000Z

23

X-ray Absorption Spectroscopy  

E-Print Network (OSTI)

type: Review X-ray Absorption Spectroscopy Junko Yano andPhotosystem II; XAS, X-ray absorption spectroscopy; EXAFS,X-ray absorption fine structure; EPR, electron paramagnetic

Yano, Junko

2010-01-01T23:59:59.000Z

24

X-ray laser  

DOE Patents (OSTI)

An X-ray laser (10) that lases between the K edges of carbon and oxygen, i.e. between 44 and 23 Angstroms, is provided. The laser comprises a silicon (12) and dysprosium (14) foil combination (16) that is driven by two beams (18, 20) of intense line focused (22, 24) optical laser radiation. Ground state nickel-like dysprosium ions (34) are resonantly photo-pumped to their upper X-ray laser state by line emission from hydrogen-like silicon ions (32). The novel X-ray laser should prove especially useful for the microscopy of biological specimens.

Nilsen, Joseph (Livermore, CA)

1991-01-01T23:59:59.000Z

25

X-Ray Generators  

Science Journals Connector (OSTI)

There are many types of X-ray generators sold commercially. The following are some of ... that should be considered when selecting a particular generator for a particular purpose. All the companies listed below s...

Reuben Rudman

1972-01-01T23:59:59.000Z

26

Cosmic rays in astrospheres  

E-Print Network (OSTI)

Cosmic rays passing through large astrospheres can be efficiently cooled inside these "cavities" in the interstellar medium. Moreover, the energy spectra of these energetic particles are already modulated in front of the astrospherical bow shocks. We study the cosmic ray flux in and around lambda Cephei as an example for an astrosphere. The large-scale plasma flow is modeled hydrodynamically with radiative cooling. We studied the cosmic ray flux in a stellar wind cavity using a transport model based on stochastic differential equations. The required parameters, most importantly, the elements of the diffusion tensor, are based on the heliospheric parameters. The magnetic field required for the diffusion coefficients is calculated kinematically. We discuss the transport in an astrospheric scenario with varying parameters for the transport coefficients. We show that large stellar wind cavities can act as sinks for the galactic cosmic ray flux and thus can give rise to small-scale anisotropies in the direction to...

Scherer, Klaus; Bomans, Dominik; Ferreira, Stefan; Fichtner, Horst; Kleimann, Jens; Strauss, Dutoit; Weis, Kerstin; Wiengarten, Tobias; Wodzinski, Thomas

2015-01-01T23:59:59.000Z

27

Gamma-Ray Bursts  

E-Print Network (OSTI)

Gamma-ray bursts are the most luminous explosions in the Universe, and their origin and mechanism are the focus of intense research and debate. More than three decades after their discovery, and after pioneering breakthroughs from space and ground experiments, their study is entering a new phase with the recently launched Swift satellite. The interplay between these observations and theoretical models of the prompt gamma ray burst and its afterglow is reviewed.

P. Meszaros

2006-05-30T23:59:59.000Z

28

Cosmic Rays and Gamma Ray Bursts From Microblazars  

E-Print Network (OSTI)

Highly relativistic jets from merger and accretion induced collapse of compact stellar objects, which may produce the cosmological gamma ray bursts (GRBs), are also very efficient and powerful cosmic ray accelerators. The expected luminosity, energy spectrum and chemical composition of cosmic rays from Galactic GRBs, most of which do not point in our direction, can explain the observed properties of Galactic cosmic rays.

Arnon Dar

1998-09-13T23:59:59.000Z

29

Gamma ray camera  

DOE Patents (OSTI)

A gamma ray camera for detecting rays emanating from a radiation source such as an isotope. The gamma ray camera includes a sensor array formed of a visible light crystal for converting incident gamma rays to a plurality of corresponding visible light photons, and a photosensor array responsive to the visible light photons in order to form an electronic image of the radiation therefrom. The photosensor array is adapted to record an integrated amount of charge proportional to the incident gamma rays closest to it, and includes a transparent metallic layer, photodiode consisting of a p-i-n structure formed on one side of the transparent metallic layer, and comprising an upper p-type layer, an intermediate layer and a lower n-type layer. In the preferred mode, the scintillator crystal is composed essentially of a cesium iodide (CsI) crystal preferably doped with a predetermined amount impurity, and the p-type upper intermediate layers and said n-type layer are essentially composed of hydrogenated amorphous silicon (a-Si:H). The gamma ray camera further includes a collimator interposed between the radiation source and the sensor array, and a readout circuit formed on one side of the photosensor array.

Perez-Mendez, Victor (Berkeley, CA)

1997-01-01T23:59:59.000Z

30

Gamma ray camera  

DOE Patents (OSTI)

A gamma ray camera is disclosed for detecting rays emanating from a radiation source such as an isotope. The gamma ray camera includes a sensor array formed of a visible light crystal for converting incident gamma rays to a plurality of corresponding visible light photons, and a photosensor array responsive to the visible light photons in order to form an electronic image of the radiation therefrom. The photosensor array is adapted to record an integrated amount of charge proportional to the incident gamma rays closest to it, and includes a transparent metallic layer, photodiode consisting of a p-i-n structure formed on one side of the transparent metallic layer, and comprising an upper p-type layer, an intermediate layer and a lower n-type layer. In the preferred mode, the scintillator crystal is composed essentially of a cesium iodide (CsI) crystal preferably doped with a predetermined amount impurity, and the p-type upper intermediate layers and said n-type layer are essentially composed of hydrogenated amorphous silicon (a-Si:H). The gamma ray camera further includes a collimator interposed between the radiation source and the sensor array, and a readout circuit formed on one side of the photosensor array. 6 figs.

Perez-Mendez, V.

1997-01-21T23:59:59.000Z

31

X-ray beam finder  

DOE Patents (OSTI)

An X-ray beam finder for locating a focal spot of an X-ray tube includes a mass of X-ray opaque material having first and second axially-aligned, parallel-opposed faces connected by a plurality of substantially identical parallel holes perpendicular to the faces and a film holder for holding X-ray sensitive film tightly against one face while the other face is placed in contact with the window of an X-ray head.

Gilbert, H.W.

1983-06-16T23:59:59.000Z

32

Cosmic Ray Physics  

E-Print Network (OSTI)

Cosmic ray story begins at the beginning of XX century. More then 100 years later, most of the main issues are still open questions, as sources, acceleration mechanism, propagation and composition. There is a continuing fascination with the studies of cosmic radiation mostly from the several contradictions connected to its observation. The radiation has an energy spectrum ranging from $\\sim$ 1 GeV to beyond 10$^{20}$ eV with a flux going from 1 particle per m$^2$ per $\\mu$s to less then 1 particle per km$^2$ per century, and so very different experimental techniques are needed to perform cosmic ray measurements in the different energy intervals. In this contribution the actual experimental status of cosmic ray knowledge will be reviewed.

D'Urso, Domenico

2014-01-01T23:59:59.000Z

33

X-ray Spectrometry  

Science Journals Connector (OSTI)

These provide excellent energy resolution for a wide range of X-ray energies, from the optical range up to several kiloelectronvolts. ... The Astro-E2 launched in 2005 was the first mission that contained a low-temperature microcalorimeter-based observatory, and three more low-temperature detector-based observatories are being developed (NeXT, Constellation-X, ZEUS). ...

Imre Szalki; Jnos Osn; Ren E. Van Grieken

2006-05-10T23:59:59.000Z

34

Gamma?ray bursts  

Science Journals Connector (OSTI)

The distribution of ??ray bursts as observed by BATSE rules out the galactic disk origin and it is consistent with the cosmological origin. Much work is currently done to reconcile galactic halo distribution with the absence of dipole and quadrupole moments in the positions of BATSE bursts. A relativistic expansion of the source is implied by both the halo as well as cosmological origin.

Bohdan Paczy?ski

1993-01-01T23:59:59.000Z

35

Cosmic ray research Public lecture  

E-Print Network (OSTI)

energy cosmic rays in Argentina 2 p.m., Wednesday, October 6, 2010 128 Jabara Hall Watkins Visiting powerful, high-energy cosmic rays that periodically bombard Earth. The project includes more than 450

36

X-Ray Afterglows from Gamma-Ray Bursts  

Science Journals Connector (OSTI)

We consider possible interpretations of the recently detected X-ray afterglow from the gamma-ray burst source GRB 970228. Cosmological and Galactic models of gamma-ray bursts predict different flux and spectral evolution of X-ray afterglows. We show that models based on adiabatic expansion of relativistic forward shocks require very efficient particle energization or postburst reacceleration during the expansion. Cooling neutron star models predict a very distinctive spectral and flux evolution that can be tested in current X-ray data.

M. Tavani

1997-01-01T23:59:59.000Z

37

Gamma-ray burst models  

Science Journals Connector (OSTI)

...research-article Discussion Meeting Issue Gamma-ray bursts organized by Alan Wells, Ralph...J. Wijers and Martin Rees Gamma-ray burst models Andrew King * * ( ark...various possibilities for making gamma-ray bursts, particularly from close binaries...

2007-01-01T23:59:59.000Z

38

Tunable X-ray source  

DOE Patents (OSTI)

A method for the production of X-ray bunches tunable in both time and energy level by generating multiple photon, X-ray, beams through the use of Thomson scattering. The method of the present invention simultaneously produces two X-ray pulses that are tunable in energy and/or time.

Boyce, James R. (Williamsburg, VA)

2011-02-08T23:59:59.000Z

39

Cosmic Ray Telescopes  

NLE Websites -- All DOE Office Websites (Extended Search)

Cosmic Ray Muon Detectors Cosmic Ray Muon Detectors Particle Physics Using Nature's Accelerator Somewhere out there is a list of "10 Things a Physics Teacher is Least Likely to Say." If one were to find this list, it would have on it such gems as #7. Let's challenge the PE Dept to a game of rugby and #4. I don't care if you understand the concept, just give me the correct answer to 12 sig figs. Finally, you'd get down to the biggie, the thing physics teachers never say: #1. Let's do a particle physics lab right here at Podunk Corners High! The traditional reasons for this are that everyone knows that particle physics is only done with Vastly Expensive and Complicated Equipment run by casts of thousands of Highly Qualified Scientists and that particle physics is Difficult and Arcane.

40

X-ray Spectrometry  

Science Journals Connector (OSTI)

The segmented STJ operated at total count rates of above 105 counts/s, and the best-achieved energy resolution of their single STJ was found to be 10 eV for X-ray energies below 1 keV. ... The Mo?Au TES, with an operating temperature of 230 mK, was developed for the Constellation-X mission and the energy resolution of the spectrometer is ?28 eV at 3.3 keV. ...

Imre Szalki; Szabina B. Trk; Jasna Injuk; Ren E. Van Grieken

2002-05-18T23:59:59.000Z

Note: This page contains sample records for the topic "ray 202-586-5077 tosha" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

High energy cosmic rays, gamma rays and neutrinos from AGN  

E-Print Network (OSTI)

The author reviews a model for the emission of high energy cosmic rays, gamma-rays and neutrinos from AGN (Active Galactic Nuclei) that he has proposed since 1985. Further discussion of the knee energy phenomenon of the cosmic ray energy spectrum requires the existence of a heavy particle with mass in the knee energy range. A possible method of detecting such a particle in the Pierre Auger Project is suggested. Also presented is a relation between the spectra of neutrinos and gamma-rays emitted from AGN. This relation can be tested by high energy neutrino detectors such as ICECUBE, the Mediterranean Sea Detector and possibly by the Pierre Auger Project.

Yukio Tomozawa

2008-02-03T23:59:59.000Z

42

Microsoft Word - ray_abstract  

NLE Websites -- All DOE Office Websites (Extended Search)

Change of electron capture nuclear decay rate in different media and under compression Amlan Ray Variable Energy Cyclotron Center 1AF, Bidhan Nagar Kolkata - 700064 India The...

43

Gamma-ray burst populations.  

E-Print Network (OSTI)

??Over the last fifty years the field of gamma-ray bursts has shown incredible growth, but the amassing of data has also left observers and theorists (more)

Virgili, Francisco J.

2011-01-01T23:59:59.000Z

44

X-ray Absorption Spectroscopy  

SciTech Connect

This review gives a brief description of the theory and application of X-ray absorption spectroscopy, both X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS), especially, pertaining to photosynthesis. The advantages and limitations of the methods are discussed. Recent advances in extended EXAFS and polarized EXAFS using oriented membranes and single crystals are explained. Developments in theory in understanding the XANES spectra are described. The application of X-ray absorption spectroscopy to the study of the Mn4Ca cluster in Photosystem II is presented.

Yano, Junko; Yachandra, Vittal K.

2009-07-09T23:59:59.000Z

45

X-ray fluorescence mapping  

NLE Websites -- All DOE Office Websites (Extended Search)

biololgical cells, over the measurement of impurities in solar cells, to the rare earth content of geological materials. A somewhat 'typical' layout for a X-ray fluorescence...

46

Light Curves of Swift Gamma Ray Bursts  

E-Print Network (OSTI)

Recent observations from the Swift gamma-ray burst mission indicate that a fraction of gamma ray bursts are characterized by a canonical behaviour of the X-ray afterglows. We present an effective theory which allows us to account for X-ray light curves of both (short - long) gamma ray bursts and X-ray rich flashes. We propose that gamma ray bursts originate from massive magnetic powered pulsars.

Paolo Cea

2006-09-22T23:59:59.000Z

47

Ultrahigh Energy Cosmic Rays and Prompt TeV Gamma Rays from Gamma Ray Bursts  

E-Print Network (OSTI)

Gamma Ray Bursts (GRBs) have been proposed as one {\\it possible} class of sources of the Ultrahigh Energy Cosmic Ray (UHECR) events observed up to energies $\\gsim10^{20}\\ev$. The synchrotron radiation of the highest energy protons accelerated within the GRB source should produce gamma rays up to TeV energies. Here we briefly discuss the implications on the energetics of the GRB from the point of view of the detectability of the prompt TeV gamma rays of proton-synchrotron origin in GRBs in the up-coming ICECUBE muon detector in the south pole.

Pijushpani Bhattacharjee; Nayantara Gupta

2003-05-12T23:59:59.000Z

48

Cosmic Rays and Experiment CZELTA  

SciTech Connect

This paper gives a review of the physics of cosmic rays with emphasis on the methods of detection and study. A summary is given of the Czech project CZELTA which is part of a multinational program to study cosmic rays with energies above 10{sup 14} eV.

Smolek, Karel; Nyklicek, Michal [Institute of Experimental and Applied Physics, Czech Technical University in Prague, Horska 3a/22, 128 00 Prague 2 (Czech Republic); Kovacikova, Petra [Faculty of Philosophy and Science, Silesian University in Opava, Bezrucovo namesti 13, 746 01 Opava (Czech Republic)

2007-11-26T23:59:59.000Z

49

Gamma-ray events thunderclouds  

E-Print Network (OSTI)

stage of rocket-triggered lightning #12;The gamma-ray flash occurred at the same time the upward leader radiation is also produced by natural lightning during the stepped leader phase. · Dwyer et al. 2003, 2004 found that x-rays are also produced by triggered lightning dart leaders. · At present, the only viable

California at Berkeley, University of

50

On the broken ray transform  

E-Print Network (OSTI)

This PhD thesis studies the broken ray transform, a generalization of the geodesic X-ray transform where geodesics are replaced with broken rays that reflect on a part of the boundary. The fundamental question is whether this transform is injective. We employ four different methods to approach this question, and each of them gives interesting results. Direct calculation can be used in a ball, where the geometry is particularly simple. If the reflecting part of the boundary is (piecewise) flat, a reflection argument can be used to reduce the problem to the usual X-ray transform. In some geometries one can use broken rays near the boundary to determine the values of the unknown function at the reflector, and even construct its Taylor series. One can also use energy estimates -- which in this context are known as Pestov identities -- to show injectivity in the presence of one convex reflecting obstacle. Many of these methods work also on Riemannian manifolds. We also discuss the periodic broken ray transform, where the integrals are taken over periodic broken rays. The broken ray transform and its periodic version have applications in other inverse problems, including Calder\\'on's problem and problems related to spectral geometry. A more detailed abstract can be found in the PDF file. This version only contains the introductory parts of the thesis. The full thesis also contains five articles.

Joonas Ilmavirta

2014-09-26T23:59:59.000Z

51

The Origin of Cosmic Rays  

ScienceCinema (OSTI)

Cosmic Rays reach the Earth from space with energies of up to more than 1020 eV, carrying information on the most powerful particle accelerators that Nature has been able to assemble. Understanding where and how cosmic rays originate has required almost one century of investigations, and, although the last word is not written yet, recent observations and theory seem now to fit together to provide us with a global picture of the origin of cosmic rays of unprecedented clarity. Here we will describe what we learned from recent observations of astrophysical sources (such as supernova remnants and active galaxies) and we will illustrate what these observations tell us about the physics of particle acceleration and transport. We will also discuss the ?end? of the Galactic cosmic ray spectrum, which bridges out attention towards the so called ultra high energy cosmic rays (UHECRs). At ~1020 eV the gyration scale of cosmic rays in cosmic magnetic fields becomes large enough to allow us to point back to their sources, thereby allowing us to perform ?cosmic ray astronomy?, as confirmed by the recent results obtained with the Pierre Auger Observatory. We will discuss the implications of these observations for the understanding of UHECRs, as well as some questions which will likely remain unanswered and will be the target of the next generation of cosmic ray experiments.

Pasquale Blasi

2010-01-08T23:59:59.000Z

52

X-ray shearing interferometer  

DOE Patents (OSTI)

An x-ray interferometer for analyzing high density plasmas and optically opaque materials includes a point-like x-ray source for providing a broadband x-ray source. The x-rays are directed through a target material and then are reflected by a high-quality ellipsoidally-bent imaging crystal to a diffraction grating disposed at 1.times. magnification. A spherically-bent imaging crystal is employed when the x-rays that are incident on the crystal surface are normal to that surface. The diffraction grating produces multiple beams which interfere with one another to produce an interference pattern which contains information about the target. A detector is disposed at the position of the image of the target produced by the interfering beams.

Koch, Jeffrey A. (Livermore, CA)

2003-07-08T23:59:59.000Z

53

Optics for X-Ray Laser and Laser Plasma Soft X-Ray Radiation  

Science Journals Connector (OSTI)

Focusing X-ray grazing incidence optics for X-ray laser and laser plasma soft X-ray radiation has been studied. ... computer code. Parabolic axisymmetric mirror for focusing Princeton X-ray laser beam and ellipso...

L. Pina; A. Inneman; R. Hudec

1996-01-01T23:59:59.000Z

54

X-ray Stacking 2008-Apr-22 Astrostats X-ray Stacking  

E-Print Network (OSTI)

X-ray Stacking 2008-Apr-22 Astrostats X-ray Stacking Tom Aldcroft SAO/CXC #12;X-ray Stacking 2008 analysis for a sample Stacking ­ mean properties of sample Chandra X-ray data (faint point sources) are photon-limited with low background => stacking in X-rays is very effective #12;X-ray Stacking 2008-Apr-22

Wolfe, Patrick J.

55

Studying Gamma Ray Bursts from a  

E-Print Network (OSTI)

Studying Gamma Ray Bursts from a new perspective! {... Unraveling some mysteries and adding new Radio Op0cal X-ray Short ( energy -ray photons... ... accompained by a considerable long las0ng emission

?umer, Slobodan

56

SMB, X-Ray Spectroscopy & Imaging  

NLE Websites -- All DOE Office Websites (Extended Search)

Home X-Ray Spectroscopy & Imaging X-Ray Spectroscopy & Imaging SSRL has five hard X-ray Spectroscopy beamlines and three Microfocus Imaging beamlines dedicated to Biological and...

57

Lensless X-Ray Imaging in Reflection  

NLE Websites -- All DOE Office Websites (Extended Search)

Lensless X-Ray Imaging in Reflection Lensless X-Ray Imaging in Reflection Print Wednesday, 26 October 2011 00:00 The advent of x-ray free-electron laser (XFEL) light sources has...

58

Center for X-Ray Optics, 1992  

SciTech Connect

This report discusses the following topics: Center for X-Ray Optics; Soft X-Ray Imaging wit Zone Plate Lenses; Biological X-Ray microscopy; Extreme Ultraviolet Lithography for Nanoelectronic Pattern Transfer; Multilayer Reflective Optics; EUV/Soft X-ray Reflectometer; Photoemission Microscopy with Reflective Optics; Spectroscopy with Soft X-Rays; Hard X-Ray Microprobe; Coronary Angiography; and Atomic Scattering Factors.

Not Available

1993-08-01T23:59:59.000Z

59

Fiber fed x-ray/gamma ray imaging apparatus  

DOE Patents (OSTI)

X-ray/gamma ray imaging apparatus is disclosed for detecting the position, energy, and intensity of x-ray/gamma ray radiation comprising scintillation means disposed in the path of such radiation and capable of generating photons in response to such radiation; first photodetection means optically bonded to the scintillation means and capable of generating an electrical signal indicative of the intensity, and energy of the radiation detected by the scintillation means; second photodetection means capable of generating an electrical signal indicative of the position of the radiation in the radiation pattern; and means for optically coupling the scintillation means to the second photodetection means. The photodetection means are electrically connected to control and storage means which may also be used to screen out noise by rejecting a signal from one photodetection means not synchronized to a signal from the other photodetection means; and also to screen out signals from scattered radiation.

Hailey, Charles J. (San Francisco, CA); Ziock, Klaus-Peter (Livermore, CA)

1992-01-01T23:59:59.000Z

60

Center for X-Ray Optics, 1991  

SciTech Connect

This report discusses: Soft-X-Ray imaging with zone-plate lenses; multilayer reflective optics; and spectroscopy with x-rays.

Not Available

1992-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "ray 202-586-5077 tosha" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Ray Smith | Y-12 National Security Complex  

NLE Websites -- All DOE Office Websites (Extended Search)

Ray Smith Ray Smith Oral History Videos Speakers INTRODUCTION Ed Bailey Jim Bailey Kay Bailey Ken Bernander Willard Brock Wilma Brooks Elmer Brummitt Naomi Brummitt Blake Case...

62

SMB, X-ray Absorption Spectroscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Absorption Spectroscopy X-ray Absorption Spectroscopy X-ray absorption spectroscopy (XAS) is a well-established technique for simultaneous local geometric and electronic structure...

63

X-ray Imaging Workshop  

NLE Websites -- All DOE Office Websites (Extended Search)

Imaging and Spectro-microscopy: Imaging and Spectro-microscopy: the Present and the Future Stanford Synchrotron Radiation Laboratory October 8-9, 2002 Organizers: John Miao & Keith Hodgson A workshop on "X-ray Imaging and Spectro-microscopy: the Present and the Future" was held on October 8-9, 2002. This workshop, organized by John Miao (SSRL) and Keith Hodgson (SSRL) provided a forum to discuss the scientific applications of a variety of imaging and spectro-microscopic techniques, including photoemission electron microscopy (PEEM), angle resolved photoemission spectroscopy (ARPES), coherent diffraction imaging, x-ray microscopy, micro-tomography, holographic imaging, and x-ray micro-probe. Twelve invited speakers discussed the important scientific applications of these techniques, and also predicted the future scientific directions with the advance of instrumentation and x-ray sources. The workshop was well attended with over fifty registered attendees.

64

Cosmic Ray Origins: An Introduction  

E-Print Network (OSTI)

Physicists have pondered the origin of cosmic rays for over a hundred years. However the last few years have seen an upsurge in the observation, progress in the theory and a genuine increase in the importance attached to the topic due to its intimate connection to the indirect detection of evidence for dark matter. The intent of this talk is to set the stage for the meeting by reviewing some of the basic features of the entire cosmic ray spectrum from GeV to ZeV energy and some of the models that have been developed. The connection will also be made to recent developments in understanding general astrophysical particle acceleration in pulsar wind nebulae, relativistic jets and gamma ray bursts. The prospects for future discoveries, which may elucidate the origin of cosmic rays, are bright.

Blandford, Roger; Yuan, Yajie

2014-01-01T23:59:59.000Z

65

Cosmic Rays and Global Warming  

E-Print Network (OSTI)

It has been claimed by others that observed temporal correlations of terrestrial cloud cover with `the cosmic ray intensity' are causal. The possibility arises, therefore, of a connection between cosmic rays and Global Warming. If true, the implications would be very great. We have examined this claim to look for evidence to corroborate it. So far we have not found any and so our tentative conclusions are to doubt it. Such correlations as appear are more likely to be due to the small variations in solar irradiance, which, of course, correlate with cosmic rays. We estimate that less than 15% of the 11-year cycle warming variations are due to cosmic rays and less than 2% of the warming over the last 35 years is due to this cause.

T. Sloan; A W Wolfendale

2007-06-28T23:59:59.000Z

66

Modeling gamma-ray bursts.  

E-Print Network (OSTI)

??Discovered serendipitously in the late 1960s, gamma-ray bursts (GRBs) are huge explosions of energy that happen at cosmological distances. They provide a grand physical playground (more)

Maxham, Amanda

2011-01-01T23:59:59.000Z

67

Miniature x-ray source  

DOE Patents (OSTI)

A miniature x-ray source utilizing a hot filament cathode. The source has a millimeter scale size and is capable of producing broad spectrum x-ray emission over a wide range of x-ray energies. The miniature source consists of a compact vacuum tube assembly containing the hot filament cathode, an anode, a high voltage feedthru for delivering high voltage to the cathode, a getter for maintaining high vacuum, a connector for initial vacuum pump down and crimp-off, and a high voltage connection for attaching a compact high voltage cable to the high voltage feedthru. At least a portion of the vacuum tube wall is fabricated from highly x-ray transparent materials, such as sapphire, diamond, or boron nitride.

Trebes, James E. (Livermore, CA); Bell, Perry M. (Tracy, CA); Robinson, Ronald B. (Modesto, CA)

2000-01-01T23:59:59.000Z

68

Neutrinos from Gamma Ray Bursts  

Science Journals Connector (OSTI)

The observed fluxes of cosmic rays and gamma rays are used to infer the maximum allowed high-energy neutrino flux allowed for Gamma Ray Bursts (GRBs) following Reference [1]. It is shown that if GRBs produce the ultrahigh-energy cosmic rays they should contribute (a) at least 10% of the extragalactic gamma ray background between 3 MeV and 30 GeV contrary to their observed energy flux which is only a minute fraction of this flux and (b) a cumulative neutrino flux a factor of 20 below the AMANDA-?2000 limit on isotropic neutrinos. This could have two implications either GRBs do not produce the ultrahigh energy cosmic rays [2 3] or that the GRBs are strongly beamed and emit most of their power at energies well above 100 GeV [4] implausibly increasing the energy requirements but consistent with the marginal detections of a few low-redshift GRBs by MILAGRITO [5] HEGRA-AIROBICC [6] and the Tibet-Array [7]. All crucial measurements to test the models will be available in the next few years. These are measurements of (i) high-energy neutrinos with AMANDA-ICECUBE or an enlarged ANTARES/NESTOR ocean detector (ii) GRB redshifts from HETE-2 follow-up studies and (iii) GRB spectra above 10 GeV with low-threshold imaging air Cherenkov telescopes such as MAGIC and the space telescopes AGILE and GLAST.

Karl Mannheim

2001-01-01T23:59:59.000Z

69

Neutrinos from Gamma Ray Bursts  

E-Print Network (OSTI)

The observed fluxes of cosmic rays and gamma rays are used to infer the maximum allowed high-energy neutrino flux allowed for Gamma Ray Bursts (GRBs), following Mannheim, Protheroe, and Rachen (2000). It is shown that if GRBs produce the ultrahigh-energy cosmic rays, they should contribute (a) at least 10% of the extragalactic gamma ray background between 3 MeV and 30 GeV, contrary to their observed energy flux which is only a minute fraction of this flux, and (b) a cumulative neutrino flux a factor of 20 below the AMANDA (Neutrino 2000) limit on isotropic neutrinos. This could have two implications, either GRBs do not produce the ultrahigh energy cosmic rays or that the GRBs are strongly beamed and emit most of their power at energies well above 100 GeV implausibly increasing the energy requirements, but consistent with the marginal detections of a few low-redshift GRBs by MILAGRITO, HEGRA-AIROBICC, and the Tibet-Array. All crucial measurements to test the models will be available in the next few years. These are measurements of (i) high-energy neutrinos with AMANDA-ICECUBE or an enlarged ANTARES/NESTOR ocean detector, (ii) GRB redshifts from HETE-2 follow-up studies, and (iii) GRB spectra above 10 GeV with low-threshold imaging air Cherenkov telescopes such as MAGIC and the space telescopes AGILE and GLAST.

Karl Mannheim

2000-10-18T23:59:59.000Z

70

Tokamak x ray diagnostic instrumentation  

SciTech Connect

Three classes of x-ray diagnostic instruments enable measurement of a variety of tokamak physics parameters from different features of the x-ray emission spectrum. (1) The soft x-ray (1 to 50 keV) pulse-height-analysis (PHA) diagnostic measures impurity concentrations from characteristic line intensities and the continuum enhancement, and measures the electron temperature from the continuum slope. (2) The Bragg x-ray crystal spectrometer (XCS) measures the ion temperature and neutral-beam-induced toroidal rotation velocity from the Doppler broadening and wavelength shift, respectively, of spectral lines of medium-Z impurity ions. Impurity charge state distributions, precise wavelengths, and inner-shell excitation and recombination rates can also be studied. X rays are diffracted and focused by a bent crystal onto a position-sensitive detector. The spectral resolving power E/..delta..E is greater than 10/sup 4/ and time resolution is 10 ms. (3) The x-ray imaging system (XIS) measures the spatial structure of rapid fluctuations (0.1 to 100 kHZ) providing information on MHD phenomena, impurity transport rates, toroidal rotation velocity, plasma position, and the electron temperature profile. It uses an array of silicon surface-barrier diodes which view different chords of the plasma through a common slot aperture and operate in current (as opposed to counting) mode. The effectiveness of shields to protect detectors from fusion-neutron radiation effects has been studied both theoretically and experimentally.

Hill, K.W.; Beiersdorfer, P.; Bitter, M.; Fredrickson, E.; Von Goeler, S.; Hsuan, H.; Johnson, L.C.; Liew, S.L.; McGuire, K.; Pare, V.

1987-01-01T23:59:59.000Z

71

Gamma-Ray Bursts, Ultra High Energy Cosmic Rays, and Cosmic Gamma-Ray Background  

E-Print Network (OSTI)

We argue that gamma-ray bursts (GRBs) may be the origin of the cosmic gamma-ray background radiation observed in GeV range. It has theoretically been discussed that protons may carry a much larger amount of energy than electrons in GRBs, and this large energy can be radiated in TeV range by synchrotron radiation of ultra-high-energy protons (\\sim 10^{20} eV). The possible detection of GRBs above 10 TeV suggested by the Tibet and HEGRA groups also supports this idea. If this is the case, most of TeV gamma-rays from GRBs are absorbed in intergalactic fields and eventually form GeV gamma-ray background, whose flux is in good agreement with the recent observation.

Tomonori Totani

1998-10-14T23:59:59.000Z

72

Aneta Siemiginowska Chandra X-ray Center  

E-Print Network (OSTI)

-ray and gamma-ray · High Energy Sky · Chandra X-ray Observatory · examples of typical X-ray data, · an example of a data analysis process · statistical challenges · what do we learn from the data? #12;What is Astronomy and phenomena do we study and how? Solar System: Sun and sollar wind, planets, moons, asteroids, comets Our

Wolfe, Patrick J.

73

Gamma ray bursts ROBERT S MACKAY  

E-Print Network (OSTI)

Gamma ray bursts ROBERT S MACKAY COLIN ROURKE We propose that a gamma ray burst is a kinematic Gamma ray bursts are intense flashes of electromagnetic radiation of cosmic origin lasting from ten accepted mechanism. We propose that a gamma ray burst is simply a kinematic effect, namely the effect

Rourke, Colin

74

X-ray Emission from Massive Stars  

E-Print Network (OSTI)

X-ray Emission from Massive Stars David Cohen Department of Physics and Astronomy Swarthmore be related to the production of X-rays on massive stars. If so, massive stars' X-rays are much different than those found our own Sun and other cooler stars like the Sun that produce X-rays via magnetic activity

Cohen, David

75

X-ray Emission from Massive Stars  

E-Print Network (OSTI)

X-ray Emission from Massive Stars David Cohen Department of Physics and Astronomy Swarthmore #12;What is the mechanism by which massive stars produce x-rays? New results from the Chandra X-ray Observatory ­ high-resolution x-ray spectroscopy: measuring Doppler broadening in emission lines Testing

Cohen, David

76

Gamma-RayGamma-Ray Bursts: from SwiftBursts: from Swift  

E-Print Network (OSTI)

Gamma-RayGamma-Ray Bursts: from SwiftBursts: from Swift to GLASTto GLAST Bing ZhangBing ZhangGehrels, et al), et al) #12;Gamma-ray bursts: the mostGamma-ray bursts: the most violent explosions fireball central photosphere internal external shocks engine (shocks) (reverse) (forward) gamma-ray UV

California at Santa Cruz, University of

77

The late X-ray afterglow of gamma-ray bursts  

Science Journals Connector (OSTI)

...research-article Discussion Meeting Issue Gamma-ray bursts organized by Alan Wells, Ralph...The late X-ray afterglow of gamma-ray bursts Richard Willingale * Paul T...of the X-ray afterglow of gamma-ray bursts (GRBs). The fit delineates...

2007-01-01T23:59:59.000Z

78

Ultrafast X-ray Absorption Spectroscopy using Laser-Driven Electron X-ray Sources (LEXS)  

E-Print Network (OSTI)

: ultrafast x-rays, x-ray absorption spectroscopy, terawatt lasers, ultrafast reaction dynamics, atomic motion atomic motion by scrutinizing the changes in x- ray absorption spectra during reactions. FirstUltrafast X-ray Absorption Spectroscopy using Laser-Driven Electron X-ray Sources (LEXS) Guangjun

Guo, Ting

79

Compact x-ray source and panel  

DOE Patents (OSTI)

A compact, self-contained x-ray source, and a compact x-ray source panel having a plurality of such x-ray sources arranged in a preferably broad-area pixelized array. Each x-ray source includes an electron source for producing an electron beam, an x-ray conversion target, and a multilayer insulator separating the electron source and the x-ray conversion target from each other. The multi-layer insulator preferably has a cylindrical configuration with a plurality of alternating insulator and conductor layers surrounding an acceleration channel leading from the electron source to the x-ray conversion target. A power source is connected to each x-ray source of the array to produce an accelerating gradient between the electron source and x-ray conversion target in any one or more of the x-ray sources independent of other x-ray sources in the array, so as to accelerate an electron beam towards the x-ray conversion target. The multilayer insulator enables relatively short separation distances between the electron source and the x-ray conversion target so that a thin panel is possible for compactness. This is due to the ability of the plurality of alternating insulator and conductor layers of the multilayer insulators to resist surface flashover when sufficiently high acceleration energies necessary for x-ray generation are supplied by the power source to the x-ray sources.

Sampayon, Stephen E. (Manteca, CA)

2008-02-12T23:59:59.000Z

80

Gamma ray bursts: The future  

Science Journals Connector (OSTI)

Gamma-ray bursts are the most dramatic and powerful cosmic explosions known. They also continue to be the most puzzling. Thanks to breakthrough observations over the last decade however a picture has emerged of gamma-ray bursts being at cosmological distances and capable of releasing more than 10 51 ergs of energy within seconds. Despite the emergence of this picture the physical origin of bursts is still unknown and the classification of different types of bursts is still in its infancy. Further understanding of gamma-ray bursts requires the wise use of our current resources and the development of new observational capabilities. We outline the current state of our knowledge of bursts and describe the present and future instrumentation which will enable us to understand these baffling blasts.

N. Gehrels; D. Macomb

2000-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ray 202-586-5077 tosha" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Beta ray flux measuring device  

DOE Patents (OSTI)

A beta ray flux measuring device in an activated member in-core instrumentation system for pressurized water reactors. The device includes collector rings positioned about an axis in the reactor's pressure boundary. Activated members such as hydroballs are positioned within respective ones of the collector rings. A response characteristic such as the current from or charge on a collector ring indicates the beta ray flux from the corresponding hydroball and is therefore a measure of the relative nuclear power level in the region of the reactor core corresponding to the specific exposed hydroball within the collector ring.

Impink, Jr., Albert J. (Murrysville, PA); Goldstein, Norman P. (Murrysville, PA)

1990-01-01T23:59:59.000Z

82

Neutrinos from Gamma Ray Bursts  

E-Print Network (OSTI)

We show that the detection of neutrinos from a typical gamma ray burst requires a kilometer-scale detector. We argue that large bursts should be visible with the neutrino telescopes under construction. We emphasize the 3 techniques by which neutrino telescopes can perform this search: by triggering on i) bursts of muons from muon neutrinos, ii) muons from air cascades initiated by high energy gamma rays and iii) showers made by relatively low energy ($\\simeq 100\\,\\mev$) electron neutrinos. Timing of neutrino-photon coincidences may yield a measurement of the neutrino mass to order $10^{-5}$~eV, an interesting range in light of the solar neutrino anomaly.

F. Halzen; G. Jaczko

1996-02-07T23:59:59.000Z

83

Gamma-ray Imaging Methods  

SciTech Connect

In this document we discuss specific implementations for gamma-ray imaging instruments including the principle of operation and describe systems which have been built and demonstrated as well as systems currently under development. There are several fundamentally different technologies each with specific operational requirements and performance trade offs. We provide an overview of the different gamma-ray imaging techniques and briefly discuss challenges and limitations associated with each modality (in the appendix we give detailed descriptions of specific implementations for many of these technologies). In Section 3 we summarize the performance and operational aspects in tabular form as an aid for comparing technologies and mapping technologies to potential applications.

Vetter, K; Mihailescu, L; Nelson, K; Valentine, J; Wright, D

2006-10-05T23:59:59.000Z

84

Periodicities in gamma ray bursts  

Science Journals Connector (OSTI)

Gamma ray burst models based on magnetic neutron stars face a problem of account for the scarcity of observed periods. Both this scarcity and the typical period found when any is detected are explained if the neutron stars are accreting in binary systems

Kent S. Wood

1984-01-01T23:59:59.000Z

85

Ultra High Energy Cosmic Rays  

Science Journals Connector (OSTI)

We discuss briefly the phenomenon of the Ultra High Energy Cosmic Rays (UHECR) particles of energy approaching and exceeding 1011 GeV. The world experimental statistics contains a small number of events but their existence is a puzzle. Its solution may lead to exciting discoveries in high energy particle astrophysics as well as in particle physics and astronomy.

Todor Stanev

2004-01-01T23:59:59.000Z

86

Ultra High Energy Cosmic Rays  

Science Journals Connector (OSTI)

......tral data at energies above 1 EeV (1018eV...from the AGASA project, are very suggestive...since these low energy cosmic rays have...the outflowing solar wind plasma and...it does on the energy limit set by the solar wind. Since there......

Roger Clay

2003-05-01T23:59:59.000Z

87

Focused X-ray source  

DOE Patents (OSTI)

Disclosed is an intense, relatively inexpensive X-ray source (as compared to a synchrotron emitter) for technological, scientific, and spectroscopic purposes. A conical radiation pattern produced by a single foil or stack of foils is focused by optics to increase the intensity of the radiation at a distance from the conical radiator. 8 figs.

Piestrup, M.A.; Boyers, D.G.; Pincus, C.I.; Maccagno, P.

1990-08-21T23:59:59.000Z

88

Surface Radiography with Alpha Rays  

Science Journals Connector (OSTI)

... , and C are deposited on the surfaces of objects which come in contact with radon. Three of them, namely, radium A, C and C, emit alpha rays ... two hours in a vessel (volume 70 c.c.) containing 1 me. of radon. Afterwards the wing was put for 8 min. on the emulsion of a photographic ...

Č. JECH

1948-02-28T23:59:59.000Z

89

Cosmic-ray driven winds  

E-Print Network (OSTI)

The theory of Galactic Winds, driven by the cosmic-ray pressure gradient, is reviewed both on the magnetohydrodynamic and on the kinetic level. In this picture the magnetic field of the Galaxy above the dense gas disk is assumed to have a flux tube geometry, the flux tubes rising locally perpendicular out of the disk to become radially directed at large distances, with the cosmic-ray sources located deep within the Galactic disk. At least above the gas disk, the magnetic fluctuations which resonantly scatter the cosmic rays are selfconsistently excited as Alf{`e}n waves by the escaping cosmic rays. The fluctuation amplitudes remain finite through nonlinear wave dissipation. The spatially increasing speed of the resulting outflow results in a diffusion-convection boundary whose position depends on particle momentum. It replaces the escape boundary of static diffusion models. New effects like overall Galactic mass and angular momentum loss as well as gas heating beyond the disk appear. Also particle re-accelera...

Vlk, Heinrich J

2014-01-01T23:59:59.000Z

90

Gamma ray bursts and extreme energy cosmic rays  

Science Journals Connector (OSTI)

Extreme Energy Cosmic Ray particles (EECR) with E>10 20 ?eV arriving on Earth with very low flux (?1 particle/Km2-1000yr) require for their investigation very large detecting areas exceeding values of 1000 km2?sr. Projects with these dimensions are now being proposed: Ground Arrays (Auger with 23500? km 2 ?sr ) or exploiting the Earth Atmosphere as seen from space (AIR WATCH and OWL with effective area reaching 1 million km2?sr). In this last case by using as a target the 10 13 tons of air viewed also the high energy neutrino flux can be investigated conveniently. Gamma Rays Bursts are suggested as a possible source for EECR and the associated High Energy neutrino flux.

Livio Scarsi

1998-01-01T23:59:59.000Z

91

Using Light to Control How X Rays Interact with Matter  

NLE Websites -- All DOE Office Websites (Extended Search)

ultrafast x-ray spectroscopy. ALS femtosecond spectroscopy beamline layout. Femtosecond x-ray and laser pulses derive from a single 800-nm laser oscillator. Femtosecond x rays...

92

Chest x-Rays | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Chest x-Rays Chest x-Rays Chest x-Rays Chest X-ray B-Reading The B-reading is a special reading of a standard chest x-ray film performed by a physician certified by the National Institute for Occupational Safety and Health (NIOSH). The reading looks for changes on the chest x-ray that may indicate exposure and disease caused by agents such as asbestos or silica. The B-reading is considered a special reading because doctors who are certified by NIOSH to perform B-readings use a specific protocol to read and record the findings as developed by the International Labour Organization (ILO). The ILO's protocol provides rules for systematically examining the x-ray in a step-by-step method and recording certain abnormalities or changes on the chest x-ray that can be attributable to

93

Lensless X-Ray Imaging in Reflection  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Imaging in Reflection Print The advent of x-ray free-electron laser (XFEL) light sources has led to an outburst of research activities in the field of lensless imaging. XFELs...

94

Lensless X-Ray Imaging in Reflection  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Imaging in Reflection Print Wednesday, 26 October 2011 00:00 The advent of x-ray free-electron laser (XFEL) light sources has led to an outburst of research activities...

95

Producing X-rays at the APS  

ScienceCinema (OSTI)

An introduction and overview of the Advanced Photon Source at Argonne National Laboratory, the technology that produces the brightest X-ray beams in the Western Hemisphere, and the research carried out by scientists using those X-rays.

None

2013-04-19T23:59:59.000Z

96

Terrestrial Effects of High Energy Cosmic Rays  

E-Print Network (OSTI)

On geological timescales, the Earth is likely to be exposed to higher than the usual flux of high energy cosmic rays (HECRs) from astrophysical sources such as nearby supernovae, gamma ray bursts or by galactic shocks. ...

Atri, Dimitra

2011-04-26T23:59:59.000Z

97

SMB, X-ray Fluorescence Imaging  

NLE Websites -- All DOE Office Websites (Extended Search)

Fluorescence Imaging X-ray Fluorescence Imaging X-ray fluorescence imaging utilizes the high brightness of SPEAR3 and focused beam generated by the uses of K-B optics, capillaries...

98

Pulsed Gamma-Ray-Burst Afterglows  

E-Print Network (OSTI)

provides a candidate for the central engine of the gamma-ray burst (GRB) mechanism, both long and short

J. Middleditch

2009-01-01T23:59:59.000Z

99

Gamma-ray burst theory after Swift  

Science Journals Connector (OSTI)

...research-article Discussion Meeting Issue Gamma-ray bursts organized by Alan Wells, Ralph...J. Wijers and Martin Rees Gamma-ray burst theory after Swift Tsvi Piran...relativistic blast wave model for gamma-ray bursts (GRBs). Together with the...

2007-01-01T23:59:59.000Z

100

Gamma-ray bursts and cosmology  

Science Journals Connector (OSTI)

...research-article Discussion Meeting Issue Gamma-ray bursts organized by Alan Wells, Ralph...J. Wijers and Martin Rees Gamma-ray bursts and cosmology D.Q Lamb...current status of the use of gamma-ray bursts (GRBs) as probes of the early...

2007-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ray 202-586-5077 tosha" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Ray Tracing JELLO Brand Paul S. Heckbert  

E-Print Network (OSTI)

Ray Tracing JELL­O ® Brand Gelatin Paul S. Heckbert Dessert Foods Division Pixar San Rafael, CA ABSTRACT Ray tracing has established itself in recent years as the most general image synthesis algorithm for ray tracing Jell­O ® brand gelatin. We believe the method may have application to other brands

Treuille, Adrien

102

Chandra X-ray Observatory Center  

E-Print Network (OSTI)

Chandra X-ray Observatory Center Harvard-Smithsonian Center for Astrophysics 60 Garden St in hot gas about 250 million light years from Earth. (Credit: X-ray: NASA/CXC/SAO/E.Bulbul, et al-Newton has revealed a mysterious X-ray signal in the data. This signal is represented in the circled data

103

X-Ray Absorption Spectroscopy of Metallobiomolecules  

E-Print Network (OSTI)

2/9/07 1 X-Ray Absorption Spectroscopy of Metallobiomolecules The Outskirts of Structural Biology 9, 07] This is a tutorial about the use of X-ray Absorption Spectroscopy (XAS) in biology, RG; Eisenberger, P; Kincaid, BM "X-ray Absorption Spectroscopy of Biological Molecules" Annu. Rev

Scott, Robert A.

104

Chandra X-ray Observatory Center  

E-Print Network (OSTI)

Chandra X-ray Observatory Center Harvard-Smithsonian Center for Astrophysics 60 Garden St million light years from Earth. (Credit: X-ray: NASA/CXC/Wesleyan Univ./R.Kilgard, et al; Optical: NASA with optical data from the Hubble Space Telescope (red, green, and blue). The X-ray data reveal hundreds

105

X-ray Spectroscopy of Cool Stars  

E-Print Network (OSTI)

High-resolution X-ray spectroscopy has addressed not only various topics in coronal physics of stars, but has also uncovered important features relevant for our understanding of stellar evolution and the stellar environment. I summarize recent progress in coronal X-ray spectroscopy and in particular also discuss new results from studies of X-rays from pre-main sequence stars.

M. Guedel

2006-09-11T23:59:59.000Z

106

X-Ray Physics Evan Berkowitz  

E-Print Network (OSTI)

X-Ray Physics Evan Berkowitz Junior, MIT Department of Physics (Dated: October 25, 2006) We measure a variety of phenomena related to X-Ray absorption and production. We present data which conforms within, as are 22 Na electron-positron annhilation lines. The importance of understanding x-rays is demonstrated

107

Chandra X-ray Observatory Center  

E-Print Network (OSTI)

Chandra X-ray Observatory Center Harvard-Smithsonian Center for Astrophysics 60 Garden St 200 million light years from Earth. (Credit: X-ray: NASA/CXC/UAH/M.Sun et al; Optical: NASA, ESA, & the Hubble Heritage Team (STScI/AURA) Caption: This composite image from the Chandra X-ray Observatory (blue

108

X-Ray Absorption Spectroscopy of Metallobiomolecules  

E-Print Network (OSTI)

9/6/09 1 X-Ray Absorption Spectroscopy of Metallobiomolecules The Outskirts of Structural Biology 6, 09] This is a tutorial about the use of X-ray Absorption Spectroscopy (XAS) in biology, RG; Eisenberger, P; Kincaid, BM "X-ray Absorption Spectroscopy of Biological Molecules" Annu. Rev

Scott, Robert A.

109

Chandra X-ray Observatory Center  

E-Print Network (OSTI)

Chandra X-ray Observatory Center Harvard-Smithsonian Center for Astrophysics 60 Garden St. Cambridge, MA 02138 USA http://chandra.harvard.edu Four Supernova Remnants: NASA's Chandra X-ray Observatory's Chandra X-ray Observatory, four newly processed images of supernova remnants dramatically illustrate

110

The Universe Viewed in Gamma-Rays 1 Properties of Gamma-ray Bursts Localized by  

E-Print Network (OSTI)

The Universe Viewed in Gamma-Rays 1 Properties of Gamma-ray Bursts Localized by the HETE-2 and localize Gamma-ray bursts (GRBs) in wide field of view. HETE-2 have been localized about 20 GRBs per year hours after the burst. 1. The High Energy Transient Explorer 2 Gamma-ray burst (GRB) is the most

Enomoto, Ryoji

111

Very high-energy gamma rays from gamma-ray bursts  

Science Journals Connector (OSTI)

...research-article Discussion Meeting Issue Gamma-ray bursts organized by Alan Wells, Ralph...high-energy gamma rays from gamma-ray bursts Paula M Chadwick * * ( p.m...progress makes the detection of a gamma-ray burst at the highest energies much...

2007-01-01T23:59:59.000Z

112

SEISMIC RAY THEORY Seismic Ray Theory presents the most comprehensive treatment of the seismic  

E-Print Network (OSTI)

#12;SEISMIC RAY THEORY Seismic Ray Theory presents the most comprehensive treatment of the seismic ray method available. This method plays an important role in seismology, seismic exploration, and the interpretation of seismic measurements. The book presents a consistent treatment of the seismic ray method, based

Cerveny, Vlastislav

113

X-RAY SPECTROMETRY X-Ray Spectrom. 2007; 36: 336342  

E-Print Network (OSTI)

X-RAY SPECTROMETRY X-Ray Spectrom. 2007; 36: 336­342 Published online in Wiley InterScience (www.interscience.wiley.com) DOI: 10.1002/xrs.980 Fish otolith trace element maps: new approaches with synchrotron microbeam x-ray of elements as they accrete through a fish's life. We apply synchrotron microbeam x-ray fluorescence methods

Limburg, Karin E.

114

X-ray Pulsations in the Supersoft X-ray Binary CAL 83  

E-Print Network (OSTI)

X-ray data reveal that the supersoft X-ray binary CAL 83 exhibits 38.4 minute pulsations at some epochs. These X-ray variations are similar to those found in some novae and are likely to be caused by nonradial pulsations the white dwarf. This is the first detection of pulsations in a classical supersoft X-ray binary.

P. C. Schmidtke; A. P. Cowley

2005-09-28T23:59:59.000Z

115

Microgap x-ray detector  

DOE Patents (OSTI)

An x-ray detector which provides for the conversion of x-ray photons into photoelectrons and subsequent amplification of these photoelectrons through the generation of electron avalanches in a thin gas-filled region subject to a high electric potential. The detector comprises a cathode (photocathode) and an anode separated by the thin, gas-filled region. The cathode may comprise a substrate, such a beryllium, coated with a layer of high atomic number material, such as gold, while the anode can be a single conducting plane of material, such as gold, or a plane of resistive material, such as chromium/silicon monoxide, or multiple areas of conductive or resistive material, mounted on a substrate composed of glass, plastic or ceramic. The charge collected from each electron avalanche by the anode is passed through processing electronics to a point of use, such as an oscilloscope.

Wuest, Craig R. (Danville, CA); Bionta, Richard M. (Livermore, CA); Ables, Elden (Livermore, CA)

1994-01-01T23:59:59.000Z

116

Gamma ray bursts and afterglow  

Science Journals Connector (OSTI)

The origin of GRBs have been a mystery for almost 30 years. Their sources emit a huge amount of energy on short time scales and the process involves extreme relativistic motion with bulk Lorentz factor of at least a few hundred. In the last two years afterglow emission in X-ray optical IR and radio was detected. The afterglow can be measured up to months and even years after the few seconds GRB. We review the theory for the ?-rays emission and the afterglow and show that it is strongly supported by observations. A recent detection of optical emission simultaneous with the GRB well agrees with theoretical predictions and further constrains the free parameters of the models. We discuss the evidence that some of the bursts are jets and discuss the prospects of polarization measurements.

Reem Sari

2000-01-01T23:59:59.000Z

117

Are gamma ray bursts nearby?  

Science Journals Connector (OSTI)

The possibility is considered that the intrinsic luminosity function of gamma ray bursters has sufficient scatter that the ln?N?ln?S relation of observed bursts not be dominated by geometric effects favoring large volumes but rather be dominated by nearby intrinsically faint bursts. It is shown that the distribution of bursts on the sky would be very granular with a significant fraction of them coming from the two or three nearest sources. Possible solutions and alternatives are briefly discussed.

David Eichler

1994-01-01T23:59:59.000Z

118

Gamma-ray burst afterglows  

E-Print Network (OSTI)

Extended, fading emissions in multi-wavelength are observed following Gamma-ray bursts (GRBs). Recent broad-band observational campaigns led by the Swift Observatory reveal rich features of these GRB afterglows. Here we review the latest observational progress and discuss the theoretical implications for understanding the central engine, composition, and geometric configuration of GRB jets, as well as their interactions with the ambient medium.

Bing Zhang

2006-11-24T23:59:59.000Z

119

Cosmic Rays at the Knee  

E-Print Network (OSTI)

Several kinds of measurements are combined in an attempt to obtain a consistent estimate of the spectrum and composition of the primary cosmic radiation through the knee region. Assuming that the knee is a signal of the high-energy end of a galactic cosmic-ray population, I discuss possible signatures of a transition to an extra-galactic population and how they might be detected.

Thomas K. Gaisser

2006-08-25T23:59:59.000Z

120

X-ray Spectroscopy of Cooling Cluster  

SciTech Connect

We review the X-ray spectra of the cores of clusters of galaxies. Recent high resolution X-ray spectroscopic observations have demonstrated a severe deficit of emission at the lowest X-ray temperatures as compared to that expected from simple radiative cooling models. The same observations have provided compelling evidence that the gas in the cores is cooling below half the maximum temperature. We review these results, discuss physical models of cooling clusters, and describe the X-ray instrumentation and analysis techniques used to make these observations. We discuss several viable mechanisms designed to cancel or distort the expected process of X-ray cluster cooling.

Peterson, J.R.; /SLAC; Fabian, A.C.; /Cambridge U., Inst. of Astron.

2006-01-17T23:59:59.000Z

Note: This page contains sample records for the topic "ray 202-586-5077 tosha" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

X-ray transmissive debris shield  

DOE Patents (OSTI)

An X-ray debris shield for use in X-ray lithography that is comprised of an X-ray window having a layer of low density foam exhibits increased longevity without a substantial increase in exposure time. The low density foam layer serves to absorb the debris emitted from the X-ray source and attenuate the shock to the window so as to reduce the chance of breakage. Because the foam is low density, the X-rays are hardly attenuated by the foam and thus the exposure time is not substantially increased.

Spielman, R.B.

1996-05-21T23:59:59.000Z

122

X-ray Spectroscopy of Cooling Clusters  

E-Print Network (OSTI)

We review the X-ray spectra of the cores of clusters of galaxies. Recent high resolution X-ray spectroscopic observations have demonstrated a severe deficit of emission at the lowest X-ray temperatures as compared to that expected from simple radiative cooling models. The same observations have provided compelling evidence that the gas in the cores is cooling below half the maximum temperature. We review these results, discuss physical models of cooling clusters, and describe the X-ray instrumentation and analysis techniques used to make these observations. We discuss several viable mechanisms designed to cancel or distort the expected process of X-ray cluster cooling.

J. R. Peterson; A. C. Fabian

2005-12-21T23:59:59.000Z

123

X-ray transmissive debris shield  

DOE Patents (OSTI)

An X-ray debris shield for use in X-ray lithography that is comprised of an X-ray window having a layer of low density foam exhibits increased longevity without a substantial increase in exposure time. The low density foam layer serves to absorb the debris emitted from the X-ray source and attenuate the shock to the window so as to reduce the chance of breakage. Because the foam is low density, the X-rays are hardly attenuated by the foam and thus the exposure time is not substantially increased.

Spielman, Rick B. (Albuquerque, NM)

1996-01-01T23:59:59.000Z

124

The Diverse Environments of Gamma-Ray Bursts  

E-Print Network (OSTI)

Galaxies of Dark Gamma-Ray Bursts: Observational Constraintsof a Very Bright Gamma- Ray Burst in a Galactic Halo 3.11.3 Gamma-Ray Burst Classi?cation . . . . . . 1.4 Gamma-Ray

Perley, Daniel Alan

2011-01-01T23:59:59.000Z

125

X-ray lithography using holographic images  

DOE Patents (OSTI)

A non-contact X-ray projection lithography method for producing a desired X-ray image on a selected surface of an X-ray-sensitive material, such as photoresist material on a wafer, the desired X-ray image having image minimum linewidths as small as 0.063 .mu.m, or even smaller. A hologram and its position are determined that will produce the desired image on the selected surface when the hologram is irradiated with X-rays from a suitably monochromatic X-ray source of a selected wavelength .lambda.. On-axis X-ray transmission through, or off-axis X-ray reflection from, a hologram may be used here, with very different requirements for monochromaticity, flux and brightness of the X-ray source. For reasonable penetration of photoresist materials by X-rays produced by the X-ray source, the wavelength X, is preferably chosen to be no more than 13.5 nm in one embodiment and more preferably is chosen in the range 1-5 nm in the other embodiment. A lower limit on linewidth is set by the linewidth of available microstructure writing devices, such as an electron beam.

Howells, Malcolm R. (Berkeley, CA); Jacobsen, Chris (Sound Beach, NY)

1995-01-01T23:59:59.000Z

126

APS Bending Magnet X-rays and  

NLE Websites -- All DOE Office Websites (Extended Search)

Irradiation of Nd-Fe-B Permanent Magnets with Irradiation of Nd-Fe-B Permanent Magnets with APS Bending Magnet X-rays and 60 Co γ-rays J. Alderman and P.K. Job APS Operations Division Advanced Photon Source J. Puhl Ionizing Radiation Division National Institute of Standards and Technology June 2000 Table of Contents Introduction Radiation-Induced Demagnetization of Permanent Magnets Resources Required γ-ray Irradiation Results and Analysis of γ-ray Irradiation X-ray Irradiation Results and Analysis of X-ray Irradiation Summary and Conclusions Acknowledgements References Tables and Figures Introduction The Advanced Photon Source (APS), as well as other third-generation synchrotron light sources, uses permanent magnets in the insertion devices to produce x-rays for scientific

127

Hard x-ray imaging from explorer  

SciTech Connect

Coded aperture X-ray detectors were applied to obtain large increases in sensitivity as well as angular resolution. A hard X-ray coded aperture detector concept is described which enables very high sensitivity studies persistent hard X-ray sources and gamma ray bursts. Coded aperture imaging is employed so that approx. 2 min source locations can be derived within a 3 deg field of view. Gamma bursts were located initially to within approx. 2 deg and X-ray/hard X-ray spectra and timing, as well as precise locations, derived for possible burst afterglow emission. It is suggested that hard X-ray imaging should be conducted from an Explorer mission where long exposure times are possible.

Grindlay, J.E.; Murray, S.S.

1981-11-01T23:59:59.000Z

128

X-ray Observations of Mrk 231  

E-Print Network (OSTI)

This paper presents new X-ray observations of Mrk 231, an active galaxy of particular interest due to its large infrared luminosity and the presence of several blueshifted broad absorption line (BAL) systems, a phenomenon observed in a small fraction of QSOs. A ROSAT HRI image of Mrk 231 is presented, this shows an extended region of soft X-ray emission, covering several tens of kpc, consistent with the extent of the host galaxy. An ASCA observation of Mrk 231 is also presented. Hard X-rays are detected but the data show no significant variability in X-ray flux. The hard X-ray continuum is heavily attenuated and X-ray column estimates range from ~ 2 x 10^{22} - 10^{23} cm^{-2} depending on whether the material is assumed to be neutral or ionized, and on the model assumed for the extended X-ray component. These ASCA data provide only the second hard X-ray spectrum of a BAL AGN presented to date. The broad-band spectral-energy-distribution of the source is discussed. While Mrk 231 is X-ray weak compared to Seyfert 1 galaxies, it has an optical-to-X-ray spectrum typical of a QSO.

T. J. Turner

1998-08-10T23:59:59.000Z

129

X-ray laser frequency near-doubling and generation of tunable coherent x rays in plasma  

E-Print Network (OSTI)

X-ray laser frequency near-doubling and generation of tunable coherent x rays in plasma P. L plasmas in which efficient x-ray laser frequency near-doubling is expected for a number of available x-ray of coherent x rays and tunable optical radiation may result in tunable coherent x-ray radiation powerful

Kaplan, Alexander

130

Gamma Ray Burst Central Engines  

E-Print Network (OSTI)

I review aspects of the theory of long-duration gamma-ray burst (GRB) central engines. I focus on the requirements of any model; these include the angular momentum of the progenitor, the power, Lorentz factor, asymmetry, and duration of the flow, and both the association and the non-association with bright supernovae. I compare and contrast the collapsar and millisecond proto-magnetar models in light of these requirements. The ability of the latter model to produce a flow with Lorentz factor ~100 while simultaneously maintaining a kinetic luminosity of ~10^50 ergs/s for a timescale of ~10-100 s is emphasized.

Todd A. Thompson

2008-07-04T23:59:59.000Z

131

Gamma?ray burst spectroscopy  

Science Journals Connector (OSTI)

The statistics and physical properties of gamma ray burst spectral features are presented following a brief review of early theoretical predictions of and experimental searches for such emission. The ?100 observations of 50 keV absorption and 400 keV emission features constitute the largest data base on neutron star lines. Although the statistical significance of individual observations is often weak and interpretation of these features as cyclotron absorption and annihilation radiation poses some theoretical problems it is clear that future observations may have far?reaching implications.

K. Hurley

1988-01-01T23:59:59.000Z

132

Gamma Ray Burst Central Engines  

Science Journals Connector (OSTI)

I review aspects of the theory of long?duration gamma?ray burst (GRB) central engines. I focus on requirements of any model; these include the angular momentum of the progenitor the power Lorentz factor asymmetry and duration of the flow and both the association and the non?association with bright supernovae. I compare and contrast the collapsar and millisecond proto?magnetar models in light of these requirements. The ability of the latter model to produce a flow with Lorentz factor ?100 while simultaneously maintaining a kinetic luminosity of ?10 50 ? ergs ? s ?1 for a timescale of ?10100? s is emphasized.

Todd A. Thompson

2008-01-01T23:59:59.000Z

133

High-energy Cosmic Rays  

E-Print Network (OSTI)

After a brief review of galactic cosmic rays in the GeV to TeV energy range, we describe some current problems of interest for particles of very high energy. Particularly interesting are two features of the spectrum, the `knee' above $10^{15}$ eV and the `ankle' above $10^{18}$ eV. An important question is whether the highest energy particles are of extra-galactic origin and, if so, at what energy the transition occurs. A theme common to all energy ranges is use of nuclear abundances as a tool for understanding the origin of the cosmic radiation.

Thomas K. Gaisser; Todor Stanev

2005-10-11T23:59:59.000Z

134

PHYSICAL PROCESSES SHAPING GAMMA-RAY BURST X-RAY AFTERGLOW LIGHT CURVES: THEORETICAL IMPLICATIONS FROM THE SWIFT X-RAY TELESCOPE OBSERVATIONS  

E-Print Network (OSTI)

PHYSICAL PROCESSES SHAPING GAMMA-RAY BURST X-RAY AFTERGLOW LIGHT CURVES: THEORETICAL IMPLICATIONS August 15; accepted 2005 December 19 ABSTRACT With the successful launch of the Swift Gamma-Ray Burst component is consistent with the tail emission of the prompt gamma-ray bursts and/or the X-ray flares

Zhang, Bing

135

Development of x-ray photoelectron microscope with an x-ray laser source  

Science Journals Connector (OSTI)

We have constructed an x-ray photoelectron microscopic system with an x-ray laser as an x-ray source. The lasing line is the Li-like Al 3d-4f transition at 15.47 nm where the recombining Al plasma is used as the x-ray laser medium. The beam from the x-ray laser cavity was then focused by using a Schwarzschild mirror coated with Mo/Si multilayers. The x-ray beam size with a diameter less than 0.5 ?m and the estimated photon number of about 210 6 ? photons/shot into the spot were achieved.

Tadayuki Ohchi; Naohiro Yamaguchi; Chiemi Fujikawa; Tamio Hara; Katsumi Watanabe; Ibuki Tanaka; Masami Taguchi

2000-01-01T23:59:59.000Z

136

A theory of Cosmic Rays  

E-Print Network (OSTI)

We present a theory of non-solar cosmic rays (CRs) in which the bulk of their observed flux is due to a single type of CR source at all energies. The total luminosity of the Galaxy, the broken power-law spectra with their observed slopes, the position of the `knee(s)' and `ankle', and the CR composition and its variation with energy are all predicted in terms of very simple and completely `standard' physics. The source of CRs is extremely `economical': it has only one parameter to be fitted to the ensemble of all of the mentioned data. All other inputs are `priors', that is, theoretical or observational items of information independent of the properties of the source of CRs, and chosen to lie in their pre-established ranges. The theory is part of a `unified view of high-energy astrophysics' --based on the `Cannonball' model of the relativistic ejecta of accreting black holes and neutron stars. The model has been extremely successful in predicting all the novel properties of Gamma Ray Bursts recently observed with help of the Swift satellite. If correct, this model is only lacking a satisfactory theoretical understanding of the `cannon' that emits the cannonballs in catastrophic processes of accretion.

Arnon Dar; Alvaro De Rujula

2006-06-19T23:59:59.000Z

137

Cosmic Ray Physics with ACORDE at LHC  

E-Print Network (OSTI)

The use of large underground high-energy physics experiments, for comic ray studies, have been used, in the past, at CERN, in order to measure, precisely, the inclusive cosmic ray flux in the energy range from 2x10^10 - 2x10^12 eV. ACORDE, ALICE Cosmic Rays DEtector, will act as Level 0 cosmic ray trigger and, together with other ALICE apparatus, will provide precise information on cosmic rays with primary energies around 10^15 - 10^17 eV. This paper reviews the main detector features, the present status, commissioning and integration with other apparatus. Finally, we discuss the ACORDE-ALICE cosmic ray physics program.

C. Pagliarone; A. Fernandez-Tellez

2007-09-19T23:59:59.000Z

138

Black Stars and Gamma Ray Bursts  

E-Print Network (OSTI)

Stars that are collapsing toward forming a black hole but are frozen near the Schwarzschild horizon are termed ``black stars''. Collisions of black stars, in contrast to black hole collisions, may be sources of gamma ray bursts, whose basic parameters are estimated quite simply and are found to be consistent with observed gamma ray bursts. Black star gamma ray bursts should be preceded by gravitational wave emission similar to that from the coalescence of black holes.

Tanmay Vachaspati

2007-06-08T23:59:59.000Z

139

Applications of soft x-ray lasers  

SciTech Connect

The high brightness and short pulse duration of soft x-ray lasers provide unique advantages for novel applications. Imaging of biological specimens using x-ray lasers has been demonstrated by several groups. Other applications to fields such as chemistry, material science, plasma diagnostics, and lithography are beginning to emerge. We review the current status of soft x-ray lasers from the perspective of applications, and present an overview of the applications currently being developed.

Skinner, C.H.

1993-08-01T23:59:59.000Z

140

Cloud chamber visualization of primary cosmic rays  

SciTech Connect

From 1948 until 1963, cloud chambers were carried to the top of the atmosphere by balloons. From these flights, which were begun by Edward P. Ney at the University of Minnesota, came the following results: discovery of heavy cosmic ray nuclei, development of scintillation and cherenkov detectors, discovery of cosmic ray electrons, and studies of solar proton events. The history of that era is illustrated here by cloud chamber photographs of primary cosmic rays.

Earl, James A. [Department of Astronomy, University of Maryland, College Park MD (United States)

2013-02-07T23:59:59.000Z

Note: This page contains sample records for the topic "ray 202-586-5077 tosha" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

High speed x-ray beam chopper  

DOE Patents (OSTI)

A fast, economical, and compact x-ray beam chopper with a small mass and a small moment of inertia whose rotation can be synchronized and phase locked to an electronic signal from an x-ray source and be monitored by a light beam is disclosed. X-ray bursts shorter than 2.5 microseconds have been produced with a jitter time of less than 3 ns.

McPherson, Armon (Oswego, IL); Mills, Dennis M. (Naperville, IL)

2002-01-01T23:59:59.000Z

142

Axion Dilaton Coupling and Gamma Ray Bursts  

Science Journals Connector (OSTI)

Axions emitted in supernovae are interesting candidates to account for Gamma-Ray Bursts provided their energy can be effectively converted...

O. Bertolami

1999-01-01T23:59:59.000Z

143

Gamma-Ray Bursts and Particle Astrophysics  

E-Print Network (OSTI)

Gamma-ray bursts are violent events occurring randomly in the sky. In this review, I will present the fireball model, proposed to explain the phenomenon of gamma-ray bursts. This model has important consequences for the production and observation at Earth of gravitational waves, high energy neutrinos, cosmic rays and high energy photons, and the second part of this review will be focused on these aspects. A last section will briefly discuss the topic of the use of gamma-ray bursts as standard candles and possible cosmological studies.

B. Gendre

2008-07-24T23:59:59.000Z

144

High-energy cosmic ray interactions  

SciTech Connect

Research into hadronic interactions and high-energy cosmic rays are closely related. On one hand--due to the indirect observation of cosmic rays through air showers--the understanding of hadronic multiparticle production is needed for deriving the flux and composition of cosmic rays at high energy. On the other hand the highest energy particles from the universe allow us to study the characteristics of hadronic interactions at energies far beyond the reach of terrestrial accelerators. This is the summary of three introductory lectures on our current understanding of hadronic interactions of cosmic rays.

Engel, Ralph [Forschungszentrum Karlsruhe, P.O. Box 3640, 76021 Karlsruhe (Germany); Orellana, Mariana [Instituto Argentino de Radioastronomia (IAR), CCT La Plata (CONICET), C.C.5, 1894 Villa Elisa, Buenos Aires (Argentina); Facultad de Ciencias Astronomicas y Geofisicas, Universidad Nacional de La Plata, Paseo del Bosque, 1900 La Plata (Argentina); Reynoso, Matias M. [Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Funes 3350, (7600) Mar del Plata (Argentina); Instituto de Investigaciones Fisicas de Mar del Plata, (UNMdP-CONICET) (Argentina); Vila, Gabriela S. [Instituto Argentino de Radioastronomia (IAR), CCT La Plata (CONICET), C.C.5, 1894 Villa Elisa, Buenos Aires (Argentina)

2009-04-30T23:59:59.000Z

145

Gamma ray burst outflows and afterglows.  

E-Print Network (OSTI)

?? We carry out a theoretical investigation of jet propagation in Gamma Ray Bursts and examine the jitter radiation mechanism as a means of producing (more)

Morsony, Brian J.

2009-01-01T23:59:59.000Z

146

Colloid Coalescence with Focused X Rays  

SciTech Connect

We show direct evidence that focused x rays enable us to merge polymer colloidal particles at room temperature. This phenomenon is ascribed to the photochemical scission of colloids with x rays, reducing the molecular weight, glass transition temperature, surface tension, and viscosity of colloids. The observation of the neck bridge growth with time shows that the x-ray-induced colloid coalescence is analogous to viscoelastic coalescence. This finding suggests a feasible protocol of photonic nanofabrication by sintering or welding of polymers, without thermal damage, using x-ray photonics.

Weon, B. M.; Kim, J. T.; Je, J. H. [X-ray Imaging Center, Department of Materials Science and Engineering, Pohang University of Science and Technology, Pohang, 790-784 (Korea, Republic of); Yi, J. M. [Samsung Advanced Institute of Technology, Yongin, Gyeonggi, 446-712 (Korea, Republic of); Wang, S.; Lee, W.-K. [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

2011-07-01T23:59:59.000Z

147

X-RAY MICROBEAM SPEECH PRODUCTION DATABASE  

E-Print Network (OSTI)

X-RAY MICROBEAM SPEECH PRODUCTION DATABASE USER'S HANDBOOK Version 1.0 (June 1994) prepared by John . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Chapter Two: XRMB History

148

X-ray laser microscope apparatus  

DOE Patents (OSTI)

A microscope consisting of an x-ray contact microscope and an optical microscope. The optical, phase contrast, microscope is used to align a target with respect to a source of soft x-rays. The source of soft x-rays preferably comprises an x-ray laser but could comprise a synchrotron or other pulse source of x-rays. Transparent resist material is used to support the target. The optical microscope is located on the opposite side of the transparent resist material from the target and is employed to align the target with respect to the anticipated soft x-ray laser beam. After alignment with the use of the optical microscope, the target is exposed to the soft x-ray laser beam. The x-ray sensitive transparent resist material whose chemical bonds are altered by the x-ray beam passing through the target mater GOVERNMENT LICENSE RIGHTS This invention was made with government support under Contract No. De-FG02-86ER13609 awarded by the Department of Energy. The Government has certain rights in this invention.

Suckewer, Szymon (Princeton, NJ); DiCicco, Darrell S. (Plainsboro, NJ); Hirschberg, Joseph G. (Coral Gables, FL); Meixler, Lewis D. (East Windsor, NJ); Sathre, Robert (Princeton, NJ); Skinner, Charles H. (Lawrenceville, NJ)

1990-01-01T23:59:59.000Z

149

Automation in X-Ray Crystallography  

Science Journals Connector (OSTI)

Automation in X-Ray Crystallography ... But in the past few years, automation procedures have been applied to intrinsically superior experimental methods. ...

S.C. ABRAHAMS

1963-06-03T23:59:59.000Z

150

Accelerated Ray Traced Animations Exploiting Temporal Coherence.  

E-Print Network (OSTI)

??Ray tracing is a well-know technique for producing realistic graphics. However, the time necessary to generate images is unacceptably long. When producing the many frames (more)

Baines, Darwin Tarry

2005-01-01T23:59:59.000Z

151

X-Ray Laser Sources for Microscopy  

Science Journals Connector (OSTI)

Progress and prospects in soft X-ray laser development at Princeton are presented. A comparison to plasma and synchrotron sources is made with a...

C. H. Skinner; D. E. Kim; A. Wouters; D. Voorhees; S. Suckewer

1988-01-01T23:59:59.000Z

152

Compound refractive X-ray lens  

DOE Patents (OSTI)

An apparatus and method for focusing X-rays. In one embodiment, his invention is a commercial-grade compound refractive X-ray lens. The commercial-grade compound refractive X-ray lens includes a volume of low-Z material. The volume of low-Z material has a first surface which is adapted to receive X-rays of commercially-applicable power emitted from a commercial-grade X-ray source. The volume of low-Z material also has a second surface from which emerge the X-rays of commercially-applicable power which were received at the first surface. Additionally, the commercial-grade compound refractive X-ray lens includes a plurality of openings which are disposed between the first surface and the second surface. The plurality of openings are oriented such that the X-rays of commercially-applicable power which are received at the first surface, pass through the volume of low-Z material and through the plurality openings. In so doing, the X-rays which emerge from the second surface are refracted to a focal point.

Nygren, David R. (Berkeley, CA); Cahn, Robert (Walnut Creek, CA); Cederstrom, Bjorn (Traellborg, SE); Danielsson, Mats (Stocksund, SE); Vestlund, Jonas (Stockholm, SE)

2000-01-01T23:59:59.000Z

153

X-Ray Science Division (XSD)  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Science Division (XSD) Search Button About Welcome Overview Visiting the APS Mission & Goals Find People Organization Charts Committees Job Openings User Information...

154

X-ray spectroscopy of neutron star low-mass X-ray binaries  

E-Print Network (OSTI)

In this thesis, I present work spanning a variety of topics relating to neutron star lowmass X-ray binaries (LMXBs) and utilize spectral information from X-ray observations to further our understanding of these sources. ...

Krauss, Miriam Ilana

2007-01-01T23:59:59.000Z

155

The Universe Viewed in Gamma-Rays 1 X-Ray and Gamma-Ray Emission from the PSR 1259-  

E-Print Network (OSTI)

threshold in the future projects. 1. Introduction PSR 1259-63 is a 48 ms radio pulsar orbiting a Be star. The pulsation is absent in the X-ray intensity. Only upper limits are reported for the high energy -ray emission accelerates electrons and positrons to the relativistic energies. We derive the energy distribution

Enomoto, Ryoji

156

Ultraluminous X-ray Sources: The most extreme X-ray binaries  

E-Print Network (OSTI)

1 Ultraluminous X-ray Sources: The most extreme X-ray binaries Luca Zampieri INAF ULXs ­ Lubiana ­ May 11, 2012- LZ #12;6 · X-ray observations of nearby galaxies show a population of pointlike, off-nuclear sources with L >> Ledd for 1 Msun (L>1.0e39 erg/s) UltraLuminous X-ray Sources (e

?umer, Slobodan

157

X-ray Diffraction (XRD) 1.0 What is X-ray Diffraction  

E-Print Network (OSTI)

X-ray Diffraction (XRD) · 1.0 What is X-ray Diffraction · 2.0 Basics of Crystallography · 3.0 Production of X-rays · 4.0 Applications of XRD · 5.0 Instrumental Sources of Error · 6.0 Conclusions #12 why the cleavage faces of crystals appear to reflect X-ray beams at certain angles of incidence (theta

Moeck, Peter

158

ON THE RECENTLY DISCOVERED CORRELATIONS BETWEEN GAMMA-RAY AND X-RAY PROPERTIES OF GAMMA-RAY BURSTS  

SciTech Connect

Recently, many correlations between the prompt {gamma}-ray emission properties and the X-ray afterglow properties of gamma-ray bursts (GRBs) have been inferred from a comprehensive analysis of the X-ray light curves of more than 650 GRBs measured with the Swift X-Ray Telescope (Swift/XRT) during the years 2004-2010. We show that these correlations are predicted by the cannonball (CB) model of GRBs. They result from the dependence of GRB observables on the bulk motion Lorentz factor and viewing angle of the jet of highly relativistic plasmoids (CBs) that produces the observed radiations by interaction with the medium through which it propagates. Moreover, despite their different physical origins, long GRBs (LGRBs) and short-hard bursts (SHBs) in the CB model share similar kinematic correlations, which can be combined into triple correlations satisfied by both LGRBs and SHBs.

Dado, Shlomo; Dar, Arnon [Physics Department, Technion, Haifa 32000 (Israel)

2013-09-20T23:59:59.000Z

159

Gravitational Waves versus X and Gamma Ray Emission in a Short Gamma-Ray Burst  

E-Print Network (OSTI)

The recent progress in the understanding the physical nature of neutron star equilibrium configurations and the first observational evidence of a genuinely short gamma-ray burst, GRB 090227B, allows to give an estimate of the gravitational waves versus the X and Gamma-ray emission in a short gamma-ray burst.

F. G. Oliveira; Jorge A. Rueda; Remo Ruffini

2014-03-28T23:59:59.000Z

160

Are extragalactic gamma ray bursts the source of the highest energy cosmic rays?  

E-Print Network (OSTI)

Recent observations with the large air shower arrays of ultra high energy cosmic rays (UHECR) and recent measurements/estimates of the redshifts of gamma ray bursts (GRBs) seem to rule out extragalactic GRBs as the source of the cosmic rays that are observed near Earth, including those with the highest energies.

Arnon Dar

1999-01-03T23:59:59.000Z

Note: This page contains sample records for the topic "ray 202-586-5077 tosha" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Watershed in X-ray Astronomy  

Science Journals Connector (OSTI)

... extent the article on page 96 of this issue of Nature from the X-ray astronomy group at the Massachusetts Institute of Technology is a record of disappointments. That is ... near the galactic centre. Now that the first satellite to be devoted to X-ray astronomy has been launched, and is apparently working successfully, the MIT article and another from ...

1971-01-08T23:59:59.000Z

162

X-Ray Identification of Element 104  

Science Journals Connector (OSTI)

The daughter x-ray identification technique has been applied to the identification of element 104. The characteristic K-series x rays from the ?-decay daughter isotope, nobelium (Z=102), have been observed in coincidence with ? particles from the decay of 4.5-sec 104257, thus providing an unequivocal determination of the parent atomic number, Z=104.

C. E. Bemis; Jr.; R. J. Silva; D. C. Hensley; O. L. Keller; Jr.; J. R. Tarrant; L. D. Hunt; P. F. Dittner; R. L. Hahn; C. D. Goodman

1973-09-03T23:59:59.000Z

163

Point-to-curve ray tracing  

Science Journals Connector (OSTI)

Point-to-curve ray tracing is an attempt at dealing with multiplicity of solutions to a generic boundary-value problem of ray tracing. In a point-to-curve tracing (P2C) the input parameters of the boundary-value....

Andrzej Hanyga

1996-01-01T23:59:59.000Z

164

Point-to-curve Ray Tracing  

Science Journals Connector (OSTI)

Point-to-curve ray tracing is an attempt at dealing with multiplicity of solutions to a generic boundary-value problem of ray tracing. In a point-to-curve tracing (P2C) the input parameters of the boundary-value....

Andrzej Hanyga

1996-01-01T23:59:59.000Z

165

LHC Communications project Dr Ray Mathias  

E-Print Network (OSTI)

LHC Communications project Dr Ray Mathias UK LHC Communications Manager ray.mathias@stfc.ac.uk LHC Communications project STFC Town Meeting 30/11/07 #12;LHC Communications project STFC funded Two-year project Partnership with the UK HEPP community LHC Communications project STFC Town Meeting 30/11/07 #12;Understanding

166

X-ray Practicals Series 1 Advanced Data Reduction  

E-Print Network (OSTI)

X-ray Practicals Series 1 Advanced Data Reduction Instructor J. Reibenspies, Ph. D. Nattamai Bhuvanesh, Ph.D. Version 1.0.0 #12;X-ray Practicals Series 2 #12;X-ray Practicals Series 3 #12;X-ray is good. The y direction is shifting the most, but the shift is ok #12;X-ray Practicals Series 5 Other

Meagher, Mary

167

Gamma-Ray Pulsar Studies With GLAST  

SciTech Connect

Some pulsars have their maximum observable energy output in the gamma-ray band, offering the possibility of using these high-energy photons as probes of the particle acceleration and interaction processes in pulsar magnetospheres. After an extended hiatus between satellite missions, the recently-launched AGILE mission and the upcoming Gamma-ray Large Area Space Telescope (GLAST) Large Area Telescope (LAT) will allow gamma-ray tests of the theoretical models developed based on past discoveries. With its greatly improved sensitivity, better angular resolution, and larger energy reach than older instruments, GLAST LAT should detect dozens to hundreds of new gamma-ray pulsars and measure luminosities, light curves, and phase-resolved spectra with unprecedented resolution. It will also have the potential to find radio-quiet pulsars like Geminga, using blind search techniques. Cooperation with radio and X-ray pulsar astronomers is an important aspect of the LAT team's planning for pulsar studies.

Thompson, D.J.; /NASA, Goddard

2011-11-23T23:59:59.000Z

168

Quantitative Measurements of X-ray Intensity  

SciTech Connect

This chapter describes the characterization of several X-ray sources and their use in calibrating different types of X-ray cameras at National Security Technologies, LLC (NSTec). The cameras are employed in experimental plasma studies at Lawrence Livermore National Laboratory (LLNL), including the National Ignition Facility (NIF). The sources provide X-rays in the energy range from several hundred eV to 110 keV. The key to this effort is measuring the X-ray beam intensity accurately and traceable to international standards. This is accomplished using photodiodes of several types that are calibrated using radioactive sources and a synchrotron source using methods and materials that are traceable to the U.S. National Institute of Standards and Technology (NIST). The accreditation procedures are described. The chapter begins with an introduction to the fundamental concepts of X-ray physics. The types of X-ray sources that are used for device calibration are described. The next section describes the photodiode types that are used for measuring X-ray intensity: power measuring photodiodes, energy dispersive photodiodes, and cameras comprising photodiodes as pixel elements. Following their description, the methods used to calibrate the primary detectors, the power measuring photodiodes and the energy dispersive photodiodes, as well as the method used to get traceability to international standards are described. The X-ray source beams can then be measured using the primary detectors. The final section then describes the use of the calibrated X-ray beams to calibrate X-ray cameras. Many of the references are web sites that provide databases, explanations of the data and how it was generated, and data calculations for specific cases. Several general reference books related to the major topics are included. Papers expanding some subjects are cited.

Haugh, M. J., Schneider, M.

2011-09-01T23:59:59.000Z

169

Supernova Remnants, Cosmic Rays, and GLAST  

SciTech Connect

The shock waves of supernova remnants (SNRs) are the traditional sources of Galactic cosmic rays, at least up to about 3000 TeV (the 'knee' energy in the cosmic-ray spectrum). In the last decade or so, X-ray observations have confirmed in a few SNRs the presence of synchrotron-X-ray-emitting electrons with energies of order 100 TeV. TeV photons from SNRs have been observed with ground-based air Cerenkov telescopes as well, but it is still unclear whether they are due to hadronic processes (inelastic p-p scattering of cosmic-ray protons from thermal gas, with secondary neutral pions decaying to gamma rays), or to leptonic processes (inverse-Compton upscattering of cosmic microwave background photons, or bremsstrahlung). The spatial structure of synchrotron X-rays as observed with the Chandra X-ray Observatory suggests the remarkable possibility that magnetic fields are amplified by orders of magnitude in strong shock waves. The electron spectra inferred from X-rays reach 100 TeV, but at that energy are cutting off steeply, well below the 'knee' energy. Are the cutoff processes due only to radiative losses so that ion spectra might continue unsteepened? Can we confirm the presence of energetic ions in SNRs at all? Are typical SNRs capable of supplying the pool of Galactic cosmic rays? Is strong magnetic-field amplification a property of strong astrophysical shocks in general? These major questions require the next generation of observational tools. I shall outline the theoretical and observational framework of particle acceleration to high energies in SNRs, and shall describe how GLAST will advance this field.

Reynolds, Steve (North Carolina State University) [North Carolina State University

2006-02-13T23:59:59.000Z

170

CONSTRAINTS ON VERY HIGH ENERGY GAMMA-RAY EMISSION FROM GAMMA-RAY BURSTS R. Atkins,1,2  

E-Print Network (OSTI)

CONSTRAINTS ON VERY HIGH ENERGY GAMMA-RAY EMISSION FROM GAMMA-RAY BURSTS R. Atkins,1,2 W. Benbow,3 emission from gamma-ray bursts (GRBs) during the prompt emission phase. Detection of >100 GeV counterparts on potential GRB models. Subject headinggs: gamma rays: bursts -- gamma rays: observations 1. INTRODUCTION

California at Santa Cruz, University of

171

The Universe Viewed in Gamma-Rays 1 Toward Ultra Short Gamma Ray Burst Ground Based De-  

E-Print Network (OSTI)

The Universe Viewed in Gamma-Rays 1 Toward Ultra Short Gamma Ray Burst Ground Based De- tection- liminary data taking started in November 2002. 1. Introduction Gamma-ray bursts observed with space Tcherenkovlightfromoneshower Few 100MeV gamma-rays Fig. 1. In an imaging telescope, -ray bursts should appear as a Cherenkov

Enomoto, Ryoji

172

X-RAY EMISSION FROM PLANETS AND COMETS: RELATIONSHIP WITH SOLAR X-RAYS AND SOLAR WIND  

E-Print Network (OSTI)

with the occurrence of solar X-ray flare, when light travel time delay is accounted, suggesting that X-rays fromX-RAY EMISSION FROM PLANETS AND COMETS: RELATIONSHIP WITH SOLAR X-RAYS AND SOLAR WIND ANIL BHARDWAJ Flight center, Greenbelt, MD 20771, USA Scattering of solar X-ray radiation mainly produces the non

?stgaard, Nikolai

173

X-Ray Diffraction The X-Ray Diffraction facility is equipped with state-of-the-art  

E-Print Network (OSTI)

X-Ray Diffraction The X-Ray Diffraction facility is equipped with state-of-the-art diffractometers offering both single crystal and powder X-Ray diffraction. Powder X-Ray Diffraction High resolution data For more details on powder X-Ray analysis contact Dr J Hriljac on 0121 414 4458 or email: j

Birmingham, University of

174

Novel X-Ray Imaging Opportunities for the RPI Linear Accelerator's Tunable, Quasi-monochromatic X-ray Source  

E-Print Network (OSTI)

Novel X-Ray Imaging Opportunities for the RPI Linear Accelerator's Tunable, Quasi-monochromatic X-ray of an intense, tunable, polarized, and quasi-monochromatic X-ray source has been ongoing at Rensselaer Polytechnic Institute since 2001 [1, 2, 3, 4, 5, 6]. This X-ray source, known as Parametric X-rays (PXR

Danon, Yaron

175

ON THE X-RAY OUTBURSTS OF TRANSIENT ANOMALOUS X-RAY PULSARS AND SOFT GAMMA-RAY REPEATERS  

SciTech Connect

We show that the X-ray outburst light curves of four transient anomalous X-ray pulsars (AXPs) and soft gamma-ray repeaters (SGRs), namely, XTE J1810-197, SGR 0501+4516, SGR 1627-41, and CXOU J164710.2-455216, can be produced by the fallback disk model that was also applied to the outburst light curves of persistent AXPs and SGRs in our earlier work. The model solves the diffusion equation for the relaxation of a disk that has been pushed back by a soft gamma-ray burst. The sets of main disk parameters used for these transient sources are very similar to each other and to those employed in our earlier models of persistent AXPs and SGRs. There is a characteristic difference between the X-ray outburst light curves of transient and persistent sources. This can be explained by the differences in the disk surface density profiles of the transient and persistent sources in quiescence indicated by their quiescent X-ray luminosities. Our results imply that a viscous disk instability operating at a critical temperature in the range of {approx}1300-2800 K is a common property of all fallback disks around AXPs and SGRs. The effect of the instability is more pronounced and starts earlier for the sources with lower quiescent luminosities, which leads to the observable differences in the X-ray enhancement light curves of transient and persistent sources. A single active disk model with the same basic disk parameters can account for the enhancement phases of both transient and persistent AXPs and SGRs. We also present a detailed parameter study to show the effects of disk parameters on the evolution of the X-ray luminosity of AXPs and SGRs in the X-ray enhancement phases.

Cal Latin-Small-Letter-Dotless-I skan, Sirin; Ertan, Uenal [Sabanc Latin-Small-Letter-Dotless-I University, Orhanl Latin-Small-Letter-Dotless-I -Tuzla, Istanbul, 34956 (Turkey)

2012-10-20T23:59:59.000Z

176

Observations of Gamma-Ray Bursts at Extreme Energies  

E-Print Network (OSTI)

of Gamma-Ray Bursts . . . . . . . . . . . . . Redshift-CRUZ OBSERVATIONS OF GAMMA-RAY BURSTS AT EXTREME ENERGIES AAncient Unvierse with Gamma-Ray Bursts, pages 330333. AIP,

Aune, Taylor

2012-01-01T23:59:59.000Z

177

X-ray Absorption Spectroscopy of Biologically Relevant Systems  

E-Print Network (OSTI)

308, Messer, B. M. X-ray Absorption Spectroscopy of AqueousSarcosine via X-ray Absorption Spectroscopy 5.1 Introductionwith Carboxylate by X-Ray Absorption Spectroscopy of Liquid

Uejio, Janel Sunayo

2010-01-01T23:59:59.000Z

178

Compact X-Ray Light Source Workshop | EMSL  

NLE Websites -- All DOE Office Websites (Extended Search)

Compact X-Ray Light Source Workshop Compact X-Ray Light Source Workshop Teller R, Terminello L, Thevuthasan T, Moncton D. 2012. "Compact X-Ray Light Source Workshop Report."...

179

Biological Imaging by Soft X-Ray Diffraction Microscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Biological Imaging by Soft X-Ray Diffraction Microscopy Biological Imaging by Soft X-Ray Diffraction Microscopy Print Wednesday, 30 November 2005 00:00 Electron and x-ray...

180

Flares in Gamma Ray Bursts  

Science Journals Connector (OSTI)

The flare activity that is observed in GRBs soon after the prompt emission with the XRT (0.310 KeV) instrument on Board of the Swift satellite is leading to important clues in relation to the physical characteristics of the mechanism generating the emission of energy in Gamma Ray Bursts. We will briefly refer to the results obtained with the recent analysis [1] and [2] and discuss the preliminary results we obtained with a new larger sample of GRBs [limited to early flares] based on fitting of the flares using the Norris 2005 profile. We find in agreement with previous results that XRT flares follow the main characteristics observed in [3] for the prompt emission spikes. The estimate of the flare energy for the subsample with redshift is rather robust and an attempt is made using the redshisft sample to estimate how the energy emitted in flares depends on time. We used a H 0 ?=?70?km/s/Mpc ? ? ?=?0.7 ? m ?=?0.3 cosmology.

G. Chincarini; J. Mao; F. Pasotti; R. Margutti; C. Guidorzi; M. G. Bernardini; Swfit Italian team

2008-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ray 202-586-5077 tosha" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

A theory of Cosmic Rays  

E-Print Network (OSTI)

We present a theory of non-solar cosmic rays (CRs) based on a single type of CR source at all energies. The total luminosity of the Galaxy, the broken power-law spectra with their observed slopes, the position of the `knee(s)' and `ankle', and the CR composition and its variation with energy are all predicted in terms of very simple and completely `standard' physics. The source of CRs is extremely `economical': it has only one parameter to be fitted to the ensemble of all of the mentioned data. All other inputs are `priors', that is, theoretical or observational items of information independent of the properties of the source of CRs, and chosen to lie in their pre-established ranges. The theory is part of a `unified view of high-energy astrophysics' --based on the `Cannonball' model of the relativistic ejecta of accreting black holes and neutron stars. If correct, this model is only lacking a satisfactory theoretical understanding of the `cannon' that emits the cannonballs in catastrophic processes of accreti...

Dar, Arnon; Dar, Arnon; Rjula, Alvaro De

2008-01-01T23:59:59.000Z

182

Lensless X-Ray Imaging in Reflection  

NLE Websites -- All DOE Office Websites (Extended Search)

Lensless X-Ray Imaging in Lensless X-Ray Imaging in Reflection Lensless X-Ray Imaging in Reflection Print Wednesday, 26 October 2011 00:00 The advent of x-ray free-electron laser (XFEL) light sources has led to an outburst of research activities in the field of lensless imaging. XFELs combine the advantages of sychrotron light sources (high brightness and x-ray wavelengths relevant to atomic and molecular phenomena) with the advantages of visible-light lasers (highly coherent beams). All of these characteristics are important for coherent x-ray diffraction imaging-lensless imaging techniques that are proving to be integral to single-shot, high-resolution imaging of both complex materials and biological samples. Existing techniques are typically designed for transmission geometry, however, and use isolated objects, requiring special sample fabrication and restricting the type of samples under investigation. Recently, researchers from the ALS and the University of Oregon have shown at ALS Beamline 12.0.2 that it is possible to form x-ray holograms in reflection geometry by using the light scattered from a sample, opening the door to lensless imaging of a wealth of new material samples.

183

Neutrinos and Gamma Rays from Galaxy Clusters  

E-Print Network (OSTI)

The next generation of neutrino and gamma-ray detectors should provide new insights into the creation and propagation of high-energy protons within galaxy clusters, probing both the particle physics of cosmic rays interacting with the background medium and the mechanisms for high-energy particle production within the cluster. In this paper we examine the possible detection of gamma-rays (via the GLAST satellite) and neutrinos (via the ICECUBE and Auger experiments) from the Coma cluster of galaxies, as well as for the gamma-ray bright clusters Abell 85, 1758, and 1914. These three were selected from their possible association with unidentified EGRET sources, so it is not yet entirely certain that their gamma-rays are indeed produced diffusively within the intracluster medium, as opposed to AGNs. It is not obvious why these inconspicuous Abell-clusters should be the first to be seen in gamma-rays, but a possible reason is that all of them show direct evidence of recent or ongoing mergers. Their identification with the EGRET gamma-ray sources is also supported by the close correlation between their radio and (purported) gamma-ray fluxes. Under favorable conditions (including a proton spectral index of 2.5 in the case of Abell 85, and sim 2.3 for Coma, and Abell 1758 and 1914), we expect ICECUBE to make as many as 0.3 neutrino detections per year from the Coma cluster of galaxies, and as many as a few per year from the Abell clusters 85, 1758, and 1914. Also, Auger may detect as many as 2 events per decade at ~ EeV energies from these gamma-ray bright clusters.

Brandon Wolfe; Fulvio Melia; Roland M. Crocker; Raymond R. Volkas

2008-07-04T23:59:59.000Z

184

A review of gamma ray bursts  

Science Journals Connector (OSTI)

Gamma-ray bursts have continued to puzzle astronomers since their discovery thirty years ago. The sources and emission mechanisms are still uncertain. The instruments on the Compton Gamma Ray Observatory most notably BATSE have produced a revolution in our understanding of bursts. BATSE found that the burst spatial distribution was isotropic but inhomogeneous a result inconsistent with any disk population of sources. The currently favored model is one in which the sources lie at cosmological distances. Recent apparent successes in the detection of X-ray and optical counterparts have generated renewed excitement.

Charles Meegan; Kevin Hurley; Alanna Connors; Brenda Dingus; Steven Matz

1997-01-01T23:59:59.000Z

185

Gamma-Ray Burst Early Afterglows  

E-Print Network (OSTI)

The successful launch and operation of NASA's Swift Gamma-Ray Burst Explorer open a new era for the multi-wavelength study of the very early afterglow phase of gamma-ray bursts (GRBs). GRB early afterglow information is essential to explore the unknown physical composition of GRB jets, the link between the prompt gamma-ray emission and the afterglow emission, the GRB central engine activity, as well as the immediate GRB environment. Here I review some of the recent theoretical efforts to address these problems and describe how the latest Swift data give answers to these outstanding questions.

Bing Zhang

2005-09-19T23:59:59.000Z

186

X-ray sources in globular clusters  

E-Print Network (OSTI)

The twelve bright (Lx>10(36) erg/s) X-ray sources in the globular clusters have lower luminosities than the brightest sources in the bulge of our galaxy. The dim (Lx<10(35) erg/s) X-ray sources in globular clusters reach higher luminosities than the cataclysmic variables in the disk of our galaxy. The first difference is a statistical fluke, as comparison with M31 indicates. The second difference is explained because the brightest of the dim sources are not cataclysmic variables, but soft X-ray transients in quiescence. This article describes the BeppoSAX, ROSAT and first Chandra observations leading to these conclusions.

Frank Verbunt

2001-11-22T23:59:59.000Z

187

The calculation of ionospheric ray paths  

E-Print Network (OSTI)

of the up-going and down- going rays, f = 30 , Y = 0. 40, bX = 0. 15, 9 =30 0 29 3-11 Simplified ionospheric ray path corresponding to the constructions shown in Figure 3-10, 30 , Y = 0. 40, bX = 0. 15, and 8 30 30 3-12 Normal index surface curves... surface curves, extraordinary mode, vertical plane; F = 30 , Y = 2. 40, bX = 0. 15 37 3-18 Normal index surface curves, extraordinary mode, vertical plane; 9 = 30 , Y = 2. 80, bX = 0. 15 38 4- 1 incidence to 60 Ordinary mode ray paths with angles...

Koehler, Buford Ray

2012-06-07T23:59:59.000Z

188

Studies of meutron star X-ray binaries  

E-Print Network (OSTI)

by type I bursts or gamma-ray bursts (GRBs), produce aspread function (PSF). Gamma-ray bursts produce a similar

Thompson, Thomas W. J.

2008-01-01T23:59:59.000Z

189

Probing Fukushima with cosmic rays should help speed cleanup...  

NLE Websites -- All DOE Office Websites (Extended Search)

Probing Fukushima with cosmic rays Probing Fukushima with cosmic rays should help speed cleanup of damaged plant The initiative could reduce the time required to clean up the...

190

Using X-Ray Computed Tomography in Pore Structure Characterization...  

NLE Websites -- All DOE Office Websites (Extended Search)

Using X-Ray Computed Tomography in Pore Structure Characterization for a Berea Sandstone: Resolution Effect. Using X-Ray Computed Tomography in Pore Structure Characterization for...

191

On Gamma-Ray Bursts  

E-Print Network (OSTI)

(Shortened) We show by example how the uncoding of Gamma-Ray Bursts (GRBs) offers unprecedented possibilities to foster new knowledge in fundamental physics and in astrophysics. After recalling some of the classic work on vacuum polarization in uniform electric fields by Klein, Sauter, Heisenberg, Euler and Schwinger, we summarize some of the efforts to observe these effects in heavy ions and high energy ion collisions. We then turn to the theory of vacuum polarization around a Kerr-Newman black hole, leading to the extraction of the blackholic energy, to the concept of dyadosphere and dyadotorus, and to the creation of an electron-positron-photon plasma. We then present a new theoretical approach encompassing the physics of neutron stars and heavy nuclei. It is shown that configurations of nuclear matter in bulk with global charge neutrality can exist on macroscopic scales and with electric fields close to the critical value near their surfaces. These configurations may represent an initial condition for the process of gravitational collapse, leading to the creation of an electron-positron-photon plasma: the basic self-accelerating system explaining both the energetics and the high energy Lorentz factor observed in GRBs. We then turn to recall the two basic interpretational paradigms of our GRB model. [...] We then turn to the special role of the baryon loading in discriminating between "genuine" short and long or "fake" short GRBs [...] We finally turn to the GRB-Supernova Time Sequence (GSTS) paradigm: the concept of induced gravitational collapse. [...] We then present some general conclusions.

Remo Ruffini; Maria Grazia Bernardini; Carlo Luciano Bianco; Letizia Caito; Pascal Chardonnet; Christian Cherubini; Maria Giovanna Dainotti; Federico Fraschetti; Andrea Geralico; Roberto Guida; Barbara Patricelli; Michael Rotondo; Jorge Armando Rueda Hernandez; Gregory Vereshchagin; She-Sheng Xue

2008-04-17T23:59:59.000Z

192

Is linear response to x-rays suitable for digital dental x-ray imaging systems? Theoretical and experimental considerations  

Science Journals Connector (OSTI)

The purpose of this study was to consider theoretically and experimentally the suitability of linear response to x-rays for digital dental x-ray imaging systems.

Keiichi Nishikawa PhD; Mamoru Wakoh DDS; PhD; Kinya Kuroyanagi DDS; PhD

2003-06-01T23:59:59.000Z

193

Thermal neutron capture gamma-rays  

SciTech Connect

The energy and intensity of gamma rays as seen in thermal neutron capture are presented. Only those (n,..cap alpha..), E = thermal, reactions for which the residual nucleus mass number is greater than or equal to 45 are included. These correspond to evaluations published in Nuclear Data Sheets. The publication source data are contained in the Evaluated Nuclear Structure Data File (ENSDF). The data presented here do not involve any additional evaluation. Appendix I lists all the residual nuclides for which the data are included here. Appendix II gives a cumulated index to A-chain evaluations including the year of publication. The capture gamma ray data are given in two tables - the Table 1 is the list of all gamma rays seen in (n,..gamma..) reaction given in the order of increasing energy; the Table II lists the gamma rays according to the nuclide.

Tuli, J.K.

1983-01-01T23:59:59.000Z

194

X-ray source for mammography  

DOE Patents (OSTI)

An x-ray source utilizing anode material which shifts the output spectrum to higher energy and thereby obtains higher penetrating ability for screening mammography application, than the currently utilized anode material. The currently used anode material (molybdenum) produces an energy x-ray spectrum of 17.5/19.6 keV, which using the anode material of this invention (e.g. silver, rhodium, and tungsten) the x-ray spectrum would be in the 20-35 keV region. Thus, the anode material of this invention provides for imaging of breasts with higher than average x-ray opacity without increase of the radiation dose, and thus reduces the risk of induced breast cancer due to the radiation dose administered for mammograms.

Logan, Clinton M. (Pleasanton, CA)

1994-01-01T23:59:59.000Z

195

Lunar/Solar effects on Cosmic Rays  

E-Print Network (OSTI)

Lunar/Solar effects on Cosmic Rays By: Sophia Bauer & Jenna Valdez #12;Introduction When cosmic, California." Moon Phase Calendar for Santa Cruz, California. N.p., n.d. Web. 02 Aug. 2012.

California at Santa Cruz, University of

196

The beginning of cosmic ray astronomy  

E-Print Network (OSTI)

We discuss the anisotropic arrival directions of the ultra high energy cosmic rays detected by Auger which I consider one of the biggest discoverie in astrophysics during the last year.

Todor Stanev

2008-08-08T23:59:59.000Z

197

Cosmic-ray muons at ultrahigh energies  

Science Journals Connector (OSTI)

Fluxes of cosmic-ray muons were estimated over the energy range extending up to 1010 GeV. Data on the production of pions; kaons; ?, ??, ?, ?, and ? mesons; charmed particles; and J/?...mesons from accelerator ex...

L. V. Volkova

2011-02-01T23:59:59.000Z

198

Ultrafast X-Ray Sources and Science  

Science Journals Connector (OSTI)

X-ray science is entering the ultrafast and ultraintense era - spurred by developments in coherent, short-wavelength sources that range from tabletop to accelerator-based. These...

Young, Linda

199

Gravitational waves and gamma-ray bursts  

E-Print Network (OSTI)

Gamma-Ray Bursts are likely associated with a catastrophic energy release in stellar mass objects. Electromagnetic observations provide important, but indirect information on the progenitor. On the other hand, gravitational waves emitted from the central source, carry direct information on its nature. In this context, I give an overview of the multi-messenger study of gamma-ray bursts that can be carried out by using electromagnetic and gravitational wave observations. I also underline the importance of joint electromagnetic and gravitational wave searches, in the absence of a gamma-ray trigger. Finally, I discuss how multi-messenger observations may probe alternative gamma-ray burst progenitor models, such as the magnetar scenario.

Alessandra Corsi; for the LIGO Scientific Collaboration; for the Virgo Collaboration

2012-05-11T23:59:59.000Z

200

X-ray induced optical reflectivity  

The change in optical reflectivity induced by intense x-ray pulses can now be used to study ultrafast many body responses in solids in the femtosecond time domain. X-ray absorption creates photoelectrons and core level holes subsequently filled by Auger or fluorescence processes, and these excitations ultimately add conduction and valence band carriers that perturb optical reflectivity.Optical absorption associated with band filling and band gap narrowing is shown to explain the basic features found in recent measurements on an insulator (silicon nitride, Si3N4), a semiconductor(gallium arsenide,GaAs), and a metal (gold,Au), obtained with ?100 fs x-ray pulses at 500-2000 eV and probed with 800 nm laser pulses. In particular GaAs exhibits an abrupt drop in reflectivity, persisting only for a time comparable to the x-ray excitation pulse duration, consistent with prompt band gap narrowing.

Durbin, Stephen M.

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ray 202-586-5077 tosha" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Can gamma-ray bursts constrain quintessence?  

E-Print Network (OSTI)

Using the narrow clustering of the geometrically corrected gamma-ray energies released by gamma-ray bursts, we investigate the possibility of using these sources as standard candles to probe cosmological parameters such as the matter density Omega_m and the cosmological constant energy density Omega_Lambda. By simulating different samples of gamma-ray bursts, we find that Omega_m can be determined with accuracy ~7% with data from 300 sources. We also show that, if Omega = 1 is due to a quintessence field, some of the models proposed in the literature may be discriminated from a Universe with cosmological constant, by a similar-sized sample of gamma-ray bursts.

T. Di Girolamo; R. Catena; M. Vietri; G. Di Sciascio

2005-04-27T23:59:59.000Z

202

SMB, X-ray Emission Spectroscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Emission Spectroscopy Beam Line 6-2b X-ray Emission Spectroscopy Beam Line 6-2b is an advanced spectroscopy experimental station on the multidisciplinary general user wiggler Beam...

203

Invariance Violation Extends the Cosmic Ray Horizon?  

E-Print Network (OSTI)

We postulate in the present paper that the energy-momentum relation is modified for very high energy particles to violate Lorentz invariance and the speed of photon is changed from the light velocity c. The violation effect is amplified, in a sensitive way to detection, through the modified kinematical constraints on the conservation of energy and momentum, in the absorption process of gamma-rays colliding against photons of longer wavelengths and converting into an electron-positron pair. For gamma-rays of energies higher than 10 TeV, the minimum energy of the soft photons for the reaction and then the absorption mean free path of gamma-rays are altered by orders of magnitude from the ones conventionally estimated. Consideration is similarly applied to high energy cosmic ray protons. The consequences may require the standard assumptions on the maximum distance that very high energy radiation can travel from to be revised.

Kifune, T

1999-01-01T23:59:59.000Z

204

Invariance Violation Extends the Cosmic Ray Horizon ?  

E-Print Network (OSTI)

We postulate in the present paper that the energy-momentum relation is modified for very high energy particles to violate Lorentz invariance and the speed of photon is changed from the light velocity c. The violation effect is amplified, in a sensitive way to detection, through the modified kinematical constraints on the conservation of energy and momentum, in the absorption process of gamma-rays colliding against photons of longer wavelengths and converting into an electron-positron pair. For gamma-rays of energies higher than 10 TeV, the minimum energy of the soft photons for the reaction and then the absorption mean free path of gamma-rays are altered by orders of magnitude from the ones conventionally estimated. Consideration is similarly applied to high energy cosmic ray protons. The consequences may require the standard assumptions on the maximum distance that very high energy radiation can travel from to be revised.

T. Kifune

1999-04-13T23:59:59.000Z

205

Gravitational waves and short gamma ray bursts.  

E-Print Network (OSTI)

??Short hard gamma-ray bursts (GRB) are believed to be produced by compact binary coalescences (CBC) { either double neutron stars or neutron star{black hole binaries. (more)

Predoi, Valeriu

2012-01-01T23:59:59.000Z

206

Ray tracing of Jovian kilometric radiation  

SciTech Connect

Results of computer ray tracing of Jovian kilometric from 56.2 kHz to 1 MHz in a model Jovian magnetosphere with an Io torus are presented. Ray tracing calculations indicate that the Io torus presents a propagation barrier to the radiation and that the Jovian kilometric radiation must be generated in the L-O mode from a source near Jupiter on field lines passing through the Io torus. One effect of the Io torus is to refract the rays away from the magnetic equator forming a shadow zone at radial distances beyond the torus. In general, at radial distances greater than 10 Jovian radii, as the wave frequency increases (>200 kHz) so does the magnetic latitude of the shadow zone. These and other features of the ray tracing calculations are in good qualitative agreement with the observations from the plasma wave receiver and planetary radio astronomy experiment on board both Voyager 1 and 2.

Green, J.L.; Gurnett, D.A.

1980-01-01T23:59:59.000Z

207

X-raying galaxies: A Chandra legacy  

Science Journals Connector (OSTI)

...Astronomy, University of Massachusetts, Amherst, MA 01003 This presentation...stellar x-ray sources in the solar neighborhood (8). The...elementsMeteoritic and solar . Geochim Cosmochim Acta 53...Astronomy, University of Massachusetts, Amherst, MA 01003, USA...

Q. Daniel Wang

2010-01-01T23:59:59.000Z

208

Small Angle X-Ray Scattering Detector  

DOE Patents (OSTI)

A detector for time-resolved small-angle x-ray scattering includes a nearly constant diameter, evacuated linear tube having an end plate detector with a first fluorescent screen and concentric rings of first fiber optic bundles for low angle scattering detection and an annular detector having a second fluorescent screen and second fiber optic bundles concentrically disposed about the tube for higher angle scattering detection. With the scattering source, i.e., the specimen under investigation, located outside of the evacuated tube on the tube's longitudinal axis, scattered x-rays are detected by the fiber optic bundles, to each of which is coupled a respective photodetector, to provide a measurement resolution, i.e., dq/q, where q is the momentum transferred from an incident x-ray to an x-ray scattering specimen, of 2% over two (2) orders of magnitude in reciprocal space, i.e., qmax/qmin approx=lO0.

Hessler, Jan P.

2004-06-15T23:59:59.000Z

209

Ray Orbach Asks Science to Serve Society  

Science Journals Connector (OSTI)

...grafting an applied component onto DOE's basic science portfolio without diluting the quality of the research itself. Michael Lubell, a lobbyist for the American Physical Society, calls the hydrogen funds a testament to Ray and praises his success...

Eli Kintisch

2006-09-29T23:59:59.000Z

210

X-Ray Nanoimaging: Instruments and Methods  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Nanoimaging: Instruments and Methods To be held as part of SPIE. http:spie.orgOP318 August 28-29, 2013; San Diego, California, USA...

211

Femtosecond X-ray protein nanocrystallography  

NLE Websites -- All DOE Office Websites (Extended Search)

Femtosecond X-ray protein nanocrystallography Authors: Chapman, H.N., Fromme, P., Barty, A., White, T.A., Kirian, R.A., Aquila, A., Hunter, M.S., Schulz, J., DePonte, D.P.,...

212

X-ray source for mammography  

DOE Patents (OSTI)

An x-ray source is described utilizing anode material which shifts the output spectrum to higher energy and thereby obtains higher penetrating ability for screening mammography application, than the currently utilized anode material. The currently used anode material (molybdenum) produces an energy x-ray spectrum of 17.5/19.6 keV, which using the anode material of this invention (e.g. silver, rhodium, and tungsten) the x-ray spectrum would be in the 20-35 keV region. Thus, the anode material of this invention provides for imaging of breasts with higher than average x-ray opacity without increase of the radiation dose, and thus reduces the risk of induced breast cancer due to the radiation dose administered for mammograms. 6 figures.

Logan, C.M.

1994-12-20T23:59:59.000Z

213

Simultaneous Planck, Swift, and Fermi observations of X-ray and gamma-ray selected blazars  

E-Print Network (OSTI)

We present simultaneous Planck, Swift, Fermi, and ground-based data for 105 blazars belonging to three samples with flux limits in the soft X-ray, hard X-ray, and gamma-ray bands. Our unique data set has allowed us to demonstrate that the selection method strongly influences the results, producing biases that cannot be ignored. Almost all the BL Lac objects have been detected by Fermi-LAT, whereas ~40% of the flat-spectrum radio quasars (FSRQs) in the radio, soft X-ray, and hard X-ray selected samples are still below the gamma-ray detection limit even after integrating 27 months of Fermi-LAT data. The radio to sub-mm spectral slope of blazars is quite flat up to ~70GHz, above which it steepens to ~-0.65. BL Lacs have significantly flatter spectra than FSRQs at higher frequencies. The distribution of the rest-frame synchrotron peak frequency (\

Giommi, P; Lahteenmaki, A; Thompson, D J; Capalbi, M; Cutini, S; Gasparrini, D; Gonzalez-Nuevo, J; Leon-Tavares, J; Lopez-Caniego, M; Mazziotta, M N; Monte, C; Perri, M; Raino, S; Tosti, G; Tramacere, A; Verrecchia, F; Aller, H D; Aller, M F; Angelakis, E; Bastieri, D; Berdyugin, A; Bonaldi, A; Bonavera, L; Burigana, C; Burrows, D N; Buson, S; Cavazzuti, E; Chincarini, G; Colafrancesco, S; Costamante, L; Cuttaia, F; D'Ammando, F; de Zotti, G; Frailis, M; Fuhrmann, L; Galeotta, S; Gargano, F; Gehrels, N; Giglietto, N; Giordano, F; Giroletti, M; Keihanen, E; King, O; Krichbaum, T P; Lasenby, A; Lavonen, N; Lawrence, C R; Leto, C; Lindfors, E; Mandolesi, N; Massardi, M; Max-Moerbeck, W; Michelson, P F; Mingaliev, M; Natoli, P; Nestoras, I; Nieppola, E; Nilsson, K; Partridge, B; Pavlidou, V; Pearson, T J; Procopio, P; Rachen, J P; Readhead, A; Reeves, R; Reimer, A; Reinthal, R; Ricciardi, S; Richards, J; Riquelme, D; Saarinen, J; Sajina, A; Sandri, M; Savolainen, P; Sievers, A; Sillanpaa, A; Sotnikova, Y; Stevenson, M; Tagliaferri, G; Takalo, L; Tammi, J; Tavagnacco, D; Terenzi, L; Toffolatti, L; Tornikoski, M; Trigilio, C; Turunen, M; Umana, G; Ungerechts, H; Villa, F; Wu, J; Zacchei, A; Zensus, J A; Zhou, X

2011-01-01T23:59:59.000Z

214

A Novel Approach to Reduce Ray Tracing Simulation Times by Predicting Number or Rays  

Science Journals Connector (OSTI)

Abstract A ray tracer, specifically designed for concentrating solar power systems, has been developed at the Solar Thermal Energy Research Group (STERG). In most ray tracers a simulation runs until a number of rays, predefined by the user, have been traced. In a novel approach the raytracer uses a user defined tolerable error and confidence interval to predict and automatically trace the required number of rays for a simulation. This reduces computational time as only the minimum required number of rays are traced. This method has not been incorporated into any of the openly available ray tracers. The method and algorithm incorporated into the STERG raytracer are described here. As a validation test case the Eurodish and optimised field layout of Planta Solar 10 plant have been simulated.

S.J. Bode; P. Gauch; D. Griffith

2014-01-01T23:59:59.000Z

215

Development of x-ray laminography under an x-ray microscopic condition  

SciTech Connect

An x-ray laminography system under an x-ray microscopic condition was developed to obtain a three-dimensional structure of laterally-extended planar objects which were difficult to observe by x-ray tomography. An x-ray laminography technique was introduced to an x-ray transmission microscope with zone plate optics. Three prototype sample holders were evaluated for x-ray imaging laminography. Layered copper grid sheets were imaged as a laminated sample. Diatomite powder on a silicon nitride membrane was measured to confirm the applicability of this method to non-planar micro-specimens placed on the membrane. The three-dimensional information of diatom shells on the membrane was obtained at a spatial resolution of sub-micron. Images of biological cells on the membrane were also obtained by using a Zernike phase contrast technique.

Hoshino, Masato; Uesugi, Kentaro; Takeuchi, Akihisa; Suzuki, Yoshio; Yagi, Naoto [Japan Synchrotron Radiation Research Institute JASRI/SPring-8, 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan)

2011-07-15T23:59:59.000Z

216

X-ray views of neutron star low-mass X-ray binaries  

E-Print Network (OSTI)

A neutron star low-mass X-ray binary is a binary stellar system with a neutron star and a low-mass companion star rotating around each other. In this system the neutron star accretes mass from the companion, and as this matter falls into the deep potential well of the neutron star, the gravitational potential energy is released primarily in the X-ray wavelengths. Such a source was first discovered in X-rays in 1962, and this discovery formally gave birth to the "X-ray astronomy". In the subsequent decades, our knowledge of these sources has increased enormously by the observations with several X-ray space missions. Here we give a brief overview of our current understanding of the X-ray observational aspects of these systems.

Sudip Bhattacharyya

2010-02-24T23:59:59.000Z

217

Gamma Ray Bursts from Ordinary Cosmic Strings  

E-Print Network (OSTI)

We give an upper estimate for the number of gamma ray bursts from ordinary (non-superconducting) cosmic strings expected to be observed at terrestrial detectors. Assuming that cusp annihilation is the mechanism responsible for the bursts we consider strings arising at a GUT phase transition and compare our estimate with the recent BATSE results. Further we give a lower limit for the effective area of future detectors designed to detect the cosmic string induced flux of gamma ray bursts.

R. H. Brandenberger; A. T. Sornborger; M. Trodden

1993-02-12T23:59:59.000Z

218

Influence of Cosmic Rays on Earth's Climate  

Science Journals Connector (OSTI)

During the last solar cycle Earth's cloud cover underwent a modulation more closely in phase with the galactic cosmic ray flux than with other solar activity parameters. Further it is found that Earth's temperature follows more closely decade variations in galactic cosmic ray flux and solar cycle length, than other solar activity parameters. The main conclusion is that the average state of the heliosphere affects Earth's climate.

Henrik Svensmark

1998-11-30T23:59:59.000Z

219

Lensless X-Ray Imaging in Reflection  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Imaging in Reflection Print X-Ray Imaging in Reflection Print The advent of x-ray free-electron laser (XFEL) light sources has led to an outburst of research activities in the field of lensless imaging. XFELs combine the advantages of sychrotron light sources (high brightness and x-ray wavelengths relevant to atomic and molecular phenomena) with the advantages of visible-light lasers (highly coherent beams). All of these characteristics are important for coherent x-ray diffraction imaging-lensless imaging techniques that are proving to be integral to single-shot, high-resolution imaging of both complex materials and biological samples. Existing techniques are typically designed for transmission geometry, however, and use isolated objects, requiring special sample fabrication and restricting the type of samples under investigation. Recently, researchers from the ALS and the University of Oregon have shown at ALS Beamline 12.0.2 that it is possible to form x-ray holograms in reflection geometry by using the light scattered from a sample, opening the door to lensless imaging of a wealth of new material samples.

220

Lensless X-Ray Imaging in Reflection  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Imaging in Reflection Print X-Ray Imaging in Reflection Print The advent of x-ray free-electron laser (XFEL) light sources has led to an outburst of research activities in the field of lensless imaging. XFELs combine the advantages of sychrotron light sources (high brightness and x-ray wavelengths relevant to atomic and molecular phenomena) with the advantages of visible-light lasers (highly coherent beams). All of these characteristics are important for coherent x-ray diffraction imaging-lensless imaging techniques that are proving to be integral to single-shot, high-resolution imaging of both complex materials and biological samples. Existing techniques are typically designed for transmission geometry, however, and use isolated objects, requiring special sample fabrication and restricting the type of samples under investigation. Recently, researchers from the ALS and the University of Oregon have shown at ALS Beamline 12.0.2 that it is possible to form x-ray holograms in reflection geometry by using the light scattered from a sample, opening the door to lensless imaging of a wealth of new material samples.

Note: This page contains sample records for the topic "ray 202-586-5077 tosha" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Argonne CNM: X-Ray Microscopy Capabilities  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Microscopy Facilities X-Ray Microscopy Facilities The Hard X-Ray Nanoprobe (HXN) facility provides scanning fluorescence, scanning diffraction, and full-field transmission and tomographic imaging capabilities with a spatial resolution of 30 nm over a spectral range of 6-12 keV. Modes of Operation Full-Field Transmission Imaging and Nanotomography X-ray transmission imaging uses both the absorption and phase shift of the X-ray beam by the sample as contrast mechanisms. Absorption contrast is used to map the sample density. Elemental constituents can be located by using differential edge contrast in this mode. Phase contrast can be highly sensitive to edges and interfaces even when the X-ray absorption is weak. These contrast mechanisms are exploited to image samples rapidly in full-field transmission mode under various environmental conditions, or combined with nanotomography methods to study the three-dimensional structure of complex and amorphous nanomaterials with the HXN.

222

Lensless X-Ray Imaging in Reflection  

NLE Websites -- All DOE Office Websites (Extended Search)

Lensless X-Ray Imaging in Reflection Print Lensless X-Ray Imaging in Reflection Print The advent of x-ray free-electron laser (XFEL) light sources has led to an outburst of research activities in the field of lensless imaging. XFELs combine the advantages of sychrotron light sources (high brightness and x-ray wavelengths relevant to atomic and molecular phenomena) with the advantages of visible-light lasers (highly coherent beams). All of these characteristics are important for coherent x-ray diffraction imaging-lensless imaging techniques that are proving to be integral to single-shot, high-resolution imaging of both complex materials and biological samples. Existing techniques are typically designed for transmission geometry, however, and use isolated objects, requiring special sample fabrication and restricting the type of samples under investigation. Recently, researchers from the ALS and the University of Oregon have shown at ALS Beamline 12.0.2 that it is possible to form x-ray holograms in reflection geometry by using the light scattered from a sample, opening the door to lensless imaging of a wealth of new material samples.

223

The Constellation X-ray mission  

Science Journals Connector (OSTI)

The Constellation-X mission is a large collecting area X-ray facility, emphasizing observations at high spectral resolution (E/?E?3003000) while covering a broad energy band (0.2540 keV). By increasing the telescope aperture and utilizing efficient spectrometers the mission will achieve a factor of 100 increased sensitivity over current high-resolution X-ray spectroscopy missions. The use of focussing optics across the 1040 keV band will provide a similar factor of 100 increased sensitivity in this band. Key technologies under development for the mission include lightweight high throughput X-ray optics, multilayer coatings to enhance the hard X-ray performance of X-ray optics, micro-calorimeter spectrometer arrays with 2 eV resolution, low-power and low-weight CCD arrays, lightweight gratings and hard X-ray detectors. When observations commence towards the end of the next decade, Constellation-X will address many pressing questions concerning the extremes of gravity and the evolution of the Universe.

N.E White; H Tananbaum

1999-01-01T23:59:59.000Z

224

Jupiter as a Giant Cosmic Ray Detector  

E-Print Network (OSTI)

We explore the feasibility of using the atmosphere of Jupiter to detect Ultra-High-Energy Cosmic Rays (UHECR's). The large surface area of Jupiter allows us to probe cosmic rays of higher energies than previously accessible. Cosmic ray extensive air showers in Jupiter's atmosphere could in principle be detected by the Large Area Telescope (LAT) on the Fermi observatory. In order to be observed, these air showers would need to be oriented toward the Earth, and would need to occur sufficiently high in the atmosphere that the gamma rays can penetrate. We demonstrate that, under these assumptions, Jupiter provides an effective cosmic ray "detector" area of $3.3 \\times 10^7$ km$^2$. We predict that Fermi-LAT should be able to detect events of energy $>10^{21}$ eV with fluence $10^{-7}$ erg cm$^{-2}$ at a rate of about one per month. The observed number of air showers may provide an indirect measure of the flux of cosmic rays $\\gtrsim 10^{20}$ eV. Extensive air showers also produce a synchrotron signature that may ...

Rimmer, Paul B; Helling, Christiane

2014-01-01T23:59:59.000Z

225

X-Ray Observations of Radio Galaxies  

E-Print Network (OSTI)

We review some of the ways that X-ray observations provide unique information on radio galaxies. Thermal bremsstrahlung X-ray emission provides detailed data on ambient densities and temperatures. These parameters in turn can be used for pressure balance calculations and can demonstrate how the ambient gas affects radio source structure. Additionally, many signatures of the interaction of radio jets and lobes with the hot gas are found in high resolution X-ray maps. Non-thermal X-ray emission from knots and hotspots of radio jets can give us constraints on the relativistic electron population for energies greater that that normally sampled in the radio (in the case of synchrotron emission) or can give us an independent estimate of the average magnetic field strength (if inverse Compton emission is the origin of the X-rays). From recent ROSAT HRI observations of 3C 390.3 and 3C 120, we show evidence that X-ray emission from knots and hotspots appears to be associated with regions of large gradients in the radio surface brightness; i.e. at the location of powerful shocks.

D. E. Harris

1998-04-20T23:59:59.000Z

226

Compton backscattered collimated x-ray source  

DOE Patents (OSTI)

A high-intensity, inexpensive and collimated x-ray source is disclosed for applications such as x-ray lithography is disclosed. An intense pulse from a high power laser, stored in a high-finesse resonator, repetitively collides nearly head-on with and Compton backscatters off a bunched electron beam, having relatively low energy and circulating in a compact storage ring. Both the laser and the electron beams are tightly focused and matched at the interaction region inside the optical resonator. The laser-electron interaction not only gives rise to x-rays at the desired wavelength, but also cools and stabilizes the electrons against intrabeam scattering and Coulomb repulsion with each other in the storage ring. This cooling provides a compact, intense bunch of electrons suitable for many applications. In particular, a sufficient amount of x-rays can be generated by this device to make it an excellent and flexible Compton backscattered x-ray (CBX) source for high throughput x-ray lithography and many other applications. 4 figs.

Ruth, R.D.; Huang, Z.

1998-10-20T23:59:59.000Z

227

Compton backscattered collmated X-ray source  

DOE Patents (OSTI)

A high-intensity, inexpensive and collimated x-ray source for applications such as x-ray lithography is disclosed. An intense pulse from a high power laser, stored in a high-finesse resonator, repetitively collides nearly head-on with and Compton backscatters off a bunched electron beam, having relatively low energy and circulating in a compact storage ring. Both the laser and the electron beams are tightly focused and matched at the interaction region inside the optical resonator. The laser-electron interaction not only gives rise to x-rays at the desired wavelength, but also cools and stabilizes the electrons against intrabeam scattering and Coulomb repulsion with each other in the storage ring. This cooling provides a compact, intense bunch of electrons suitable for many applications. In particular, a sufficient amount of x-rays can be generated by this device to make it an excellent and flexible Compton backscattered x-ray (CBX) source for high throughput x-ray lithography and many other applications.

Ruth, Ronald D. (Woodside, CA); Huang, Zhirong (Stanford, CA)

2000-01-01T23:59:59.000Z

228

Compton backscattered collimated x-ray source  

DOE Patents (OSTI)

A high-intensity, inexpensive and collimated x-ray source for applications such as x-ray lithography is disclosed. An intense pulse from a high power laser, stored in a high-finesse resonator, repetitively collides nearly head-on with and Compton backscatters off a bunched electron beam, having relatively low energy and circulating in a compact storage ring. Both the laser and the electron beams are tightly focused and matched at the interaction region inside the optical resonator. The laser-electron interaction not only gives rise to x-rays at the desired wavelength, but also cools and stabilizes the electrons against intrabeam scattering and Coulomb repulsion with each other in the storage ring. This cooling provides a compact, intense bunch of electrons suitable for many applications. In particular, a sufficient amount of x-rays can be generated by this device to make it an excellent and flexible Compton backscattered x-ray (CBX) source for high throughput x-ray lithography and many other applications.

Ruth, Ronald D. (Woodside, CA); Huang, Zhirong (Stanford, CA)

1998-01-01T23:59:59.000Z

229

Lensless X-Ray Imaging in Reflection  

NLE Websites -- All DOE Office Websites (Extended Search)

Lensless X-Ray Imaging in Reflection Print Lensless X-Ray Imaging in Reflection Print The advent of x-ray free-electron laser (XFEL) light sources has led to an outburst of research activities in the field of lensless imaging. XFELs combine the advantages of sychrotron light sources (high brightness and x-ray wavelengths relevant to atomic and molecular phenomena) with the advantages of visible-light lasers (highly coherent beams). All of these characteristics are important for coherent x-ray diffraction imaging-lensless imaging techniques that are proving to be integral to single-shot, high-resolution imaging of both complex materials and biological samples. Existing techniques are typically designed for transmission geometry, however, and use isolated objects, requiring special sample fabrication and restricting the type of samples under investigation. Recently, researchers from the ALS and the University of Oregon have shown at ALS Beamline 12.0.2 that it is possible to form x-ray holograms in reflection geometry by using the light scattered from a sample, opening the door to lensless imaging of a wealth of new material samples.

230

Lag-luminosity relation in gamma-ray burst X-ray flares  

SciTech Connect

In strict analogy to prompt pulses, X-ray flares observed by Swift-XRT in long Gamma-Ray Bursts define a lag-luminosity relation: L{sub p,iso}{sup 0.3-10} k{sup eV} {infinity}t{sub lag}{sup -0.95{+-}0.23}. The lag-luminosity is proven to be a fundamental law extending {approx}5 decades in time and {approx}5 in energy. This is direct evidence that GRB X-ray flares and prompt gamma-ray pulses are produced by the same mechanism.

Margutti, R.

2010-10-15T23:59:59.000Z

231

Are gamma-ray bursts the sources of ultra-high energy cosmic rays?  

E-Print Network (OSTI)

We reconsider the possibility that gamma-ray bursts (GRBs) are the sources of the ultra-high energy cosmic rays (UHECRs) within the internal shock model, assuming a pure proton composition of the UHECRs. For the first time, we combine the information from gamma-rays, cosmic rays, prompt neutrinos, and cosmogenic neutrinos quantitatively in a joint cosmic ray production and propagation model, and we show that the information on the cosmic energy budget can be obtained as a consequence. In addition to the neutron model, we consider alternative scenarios for the cosmic ray escape from the GRBs, i.e., that cosmic rays can leak from the sources. We find that the dip model, which describes the ankle in UHECR observations by the pair production dip, is strongly disfavored in combination with the internal shock model because a) unrealistically high baryonic loadings (energy in protons versus energy in electrons/gamma-rays) are needed for the individual GRBs and b) the prompt neutrino flux easily overshoots the corresponding neutrino bound. On the other hand, GRBs may account for the UHECRs in the ankle transition model if cosmic rays leak out from the source at the highest energies. In that case, we demonstrate that future neutrino observations can efficiently test most of the parameter space -- unless the baryonic loading is much larger than previously anticipated.

Philipp Baerwald; Mauricio Bustamante; Walter Winter

2014-07-07T23:59:59.000Z

232

A common stochastic process rules gamma-ray burst prompt emission and X-ray flares  

E-Print Network (OSTI)

Prompt gamma-ray and early X-ray afterglow emission in gamma-ray bursts (GRBs) are characterized by a bursty behavior and are often interspersed with long quiescent times. There is compelling evidence that X-ray flares are linked to prompt gamma-rays. However, the physical mechanism that leads to the complex temporal distribution of gamma-ray pulses and X-ray flares is not understood. Here we show that the waiting time distribution (WTD) of pulses and flares exhibits a power-law tail extending over 4 decades with index ~2 and can be the manifestation of a common time-dependent Poisson process. This result is robust and is obtained on different catalogs. Surprisingly, GRBs with many (>=8) gamma-ray pulses are very unlikely to be accompanied by X-ray flares after the end of the prompt emission (3.1 sigma Gaussian confidence). These results are consistent with a simple interpretation: an hyperaccreting disk breaks up into one or a few groups of fragments, each of which is independently accreted with the same pro...

Guidorzi, C; Frontera, F; Margutti, R; Baldeschi, A; Amati, L

2015-01-01T23:59:59.000Z

233

The gamma?ray burst capabilities of BATSE and the Gamma Ray Observatory  

Science Journals Connector (OSTI)

The Gamma Ray Observatory (GRO) scheduled for launch in 1990 will provide new and enhanced capabilities for the study of gamma?ray bursts. These include higher sensitivity increased time resolution broader energy coverage rapid burst data dissemination and burst location by a single spacecraft. All four of the GRO instruments have burst capabilities however the Burst and Transient Source Experiment (BATSE) is designed primarily for the study of gamma?ray bursts. The capabilities of BATSE and the GRO for gamma?ray burst studies are described.

G. J. Fishman

1988-01-01T23:59:59.000Z

234

Are gamma-ray bursts the sources of ultra-high energy cosmic rays?  

Science Journals Connector (OSTI)

Abstract We reconsider the possibility that gamma-ray bursts (GRBs) are the sources of the ultra-high energy cosmic rays (UHECRs) within the internal shock model, assuming a pure proton composition of the UHECRs. For the first time, we combine the information from gamma-rays, cosmic rays, prompt neutrinos, and cosmogenic neutrinos quantitatively in a joint cosmic ray production and propagation model, and we show that the information on the cosmic energy budget can be obtained as a consequence. In addition to the neutron model, we consider alternative scenarios for the cosmic ray escape from the GRBs, i.e., that cosmic rays can leak from the sources. We find that the dip model, which describes the ankle in UHECR observations by the pair production dip, is strongly disfavored in combination with the internal shock model because (a) unrealistically high baryonic loadings (energy in protons versus energy in electrons/gamma-rays) are needed for the individual \\{GRBs\\} and (b) the prompt neutrino flux easily overshoots the corresponding neutrino bound. On the other hand, \\{GRBs\\} may account for the \\{UHECRs\\} in the ankle transition model if cosmic rays leak out from the source at the highest energies. In that case, we demonstrate that future neutrino observations can efficiently test most of the parameter space unless the baryonic loading is much larger than previously anticipated.

Philipp Baerwald; Mauricio Bustamante; Walter Winter

2015-01-01T23:59:59.000Z

235

High energy cosmic-rays from gamma-ray burst sources: A stronger case  

E-Print Network (OSTI)

The suggested association between the sources of gamma-ray bursts (GRB's) and the sources of ultra-high energy cosmic rays (UHECR's) is based on two arguments: (i) The average energy generation rate of UHECR's is similar to the gamma-ray generation rate of GRB's, and (ii) The constraints that UHECR sources must satisfy to allow proton acceleration to >10^{20} eV are similar to those inferred for GRB sources from gamma-ray observations. We show that recent GRB and UHECR observations strengthen both arguments, and hence strengthen the suggested association.

E. Waxman

2002-10-30T23:59:59.000Z

236

Reflection soft X-ray microscope and method  

DOE Patents (OSTI)

A reflection soft X-ray microscope is provided by generating soft X-ray beams, condensing the X-ray beams to strike a surface of an object at a predetermined angle, and focusing the X-ray beams reflected from the surface onto a detector, for recording an image of the surface or near surface features of the object under observation.

Suckewer, Szymon (Princeton, NJ); Skinner, Charles H. (Lawrenceville, NJ); Rosser, Roy (Princeton, NJ)

1993-01-01T23:59:59.000Z

237

Differential phase contrast X-ray imaging system and components  

DOE Patents (OSTI)

A differential phase contrast X-ray imaging system includes an X-ray illumination system, a beam splitter arranged in an optical path of the X-ray illumination system, and a detection system arranged in an optical path to detect X-rays after passing through the beam splitter.

Stutman, Daniel; Finkenthal, Michael

2014-07-01T23:59:59.000Z

238

Gamma-Ray Studies in Boron-10  

Science Journals Connector (OSTI)

Gamma rays emanating from the 7.56-Mev level of B10 were analyzed with a five-crystal pair spectrometer. Cascade gamma rays were investigated by recording the spectra in coincidence with the 2.40, 0.72, 2.15, and 5.41-Mev gamma-ray transitions. The branching ratios for the decay of the 7.56-Mev level were found to be 76%, 9%, and 15% for 6.84, 5.41, and 2.40-Mev gamma rays, respectively. For the 2.15-Mev level, the respective branching ratios for 2.15, 1.43, and 0.41-Mev gamma rays were shown to be 16%, 29%, and 55%. The partial width for the 3.01-Mev transition was found to be less than 1% of the total width of the 5.16-Mev state in B10. Combining this result with the data of Meyer-Schtzmeister and Hanna, the gamma-ray width of the 5.16-Mev level was found to be 0.51 ev and the alpha width 32ray widths may be resolved if the 5.16-Mev state in B10 is assumed to be a doublet.

Esther L. Sprenkel and James W. Daughtry

1961-11-01T23:59:59.000Z

239

High spatial resolution X-ray and gamma ray imaging system using diffraction crystals  

DOE Patents (OSTI)

A method and a device for high spatial resolution imaging of a plurality of sources of x-ray and gamma-ray radiation are provided. The device comprises a plurality of arrays, with each array comprising a plurality of elements comprising a first collimator, a diffracting crystal, a second collimator, and a detector.

Smither, Robert K. (Hinsdale, IL)

2011-05-17T23:59:59.000Z

240

Gamma ray bursts, cosmic ray origin, and the unidentified EGRET sources  

Science Journals Connector (OSTI)

Statistical arguments show that the volume- and time-averaged kinetic power of GRBs and fireball transients (FTs) into an L* galaxy like the Milky Way is at the level of 10 40 ? ergs?s ?1 . This number though with wide uncertainties related to the internal or external shock efficiency is sufficient to power hadronic cosmic rays observed locally. The release of energy by the high-mass progenitor stars of GRBs and FTs is sufficient to power the ultrahigh energy cosmic rays as already shown by Waxman and Vietri in 1995. It is sufficient to power the cosmic rays above the knee of the cosmic-ray spectrum. Indeed all hadronic cosmic rays could originate from the high-mass (?100? M ? ) stars that collapse to black holes in the process forming GRBs and FTs. This source class represents a new solution to the problem of cosmic-ray origin. The ?10 4 10 7 black holes made by these stars could make their presence known by radiating as they accrete from the ISM by microlensing background radiations and by forming luminous binary systems. Some unidentified EGRET sources could be isolated black holes that accrete from the ISM. Better imaging and sensitivity with GLAST and TeV observatories will test this model for the unidentified ?-ray sources and this theory for cosmic-ray origin.

Charles D. Dermer

2001-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ray 202-586-5077 tosha" from the National Library of EnergyBeta (NLEBeta).
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241

COSMIC-RAY AND X-RAY HEATING OF INTERSTELLAR CLOUDS AND PROTOPLANETARY DISKS  

SciTech Connect

Cosmic-ray and X-ray heating are derived from the electron energy-loss calculations of Dalgarno, Yan, and Liu for hydrogen-helium gas mixtures. These authors treated the heating from elastic scattering and collisional de-excitation of rotationally excited hydrogen molecules. Here we consider the heating that can arise from all ionization and excitation processes, with particular emphasis on the reactions of cosmic-ray and X-ray generated ions with the heavy neutral species, which we refer to as chemical heating. In molecular regions, chemical heating dominates and can account for 50% of the energy expended in the creation of an ion pair. The heating per ion pair ranges in the limit of negligible electron fraction from {approx}4.3 eV for diffuse atomic gas to {approx}13 eV for the moderately dense regions of molecular clouds and to {approx}18 eV for the very dense regions of protoplanetary disks. An important general conclusion of this study is that cosmic-ray and X-ray heating depends on the physical properties of the medium, i.e., on the molecular and electron fractions, the total density of hydrogen nuclei, and, to a lesser extent, on the temperature. It is also noted that chemical heating, the dominant process for cosmic-ray and X-ray heating, plays a role in UV irradiated molecular gas.

Glassgold, Alfred E. [Astronomy Department, University of California, Berkeley, CA 94720-3411 (United States); Galli, Daniele [INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125 (Italy); Padovani, Marco, E-mail: aglassgold@berkeley.edu, E-mail: galli@arcetri.astro.it, E-mail: marco.padovani@lra.ens.fr [Laboratoire de Radioastronomie Millimetrique, UMR 8112 du CNRS, Ecole Normale Superieure et Observatoire de Paris, 24 rue Lhomond, F-75231 Paris Cedex 05 (France)

2012-09-10T23:59:59.000Z

242

X-Ray Observations of Unidentified H.E.S.S. Gamma-Ray Sources  

SciTech Connect

In a survey of the inner part of the Galaxy, performed with the H.E.S.S. Instrument (High energy stereoscopic system) in 2004 and 2005, a large number of new unidentified very high energy (VHE) {gamma}-ray sources above an energy of 100 GeV was discovered. Often the {gamma}-ray spectra in these sources reach energies of up to {approx} 10 TeV. These are the highest energy particles ever attributed to single astrophysical objects. While a few of these sources can be identified at other wavebands, most of these sources remain unidentified so far. A positive identification of these new g-ray sources with a counterpart object at other wavebands requires (a) a positional coincidence between the two sources,( b) a viable {gamma}-ray emission mechanism and (c) a consistent multiwavelength behavior of the two sources. X-ray observations with satellites such as XMM-Newton, Chandra or Suzaku provide one of the best channels to studying these enigmatic {gamma}-ray sources at other wavebands, since they combine high angular resolution and sensitivity with the ability to access non-thermal electrons through their synchrotron emission. We therefore have started a dedicated program to investigate VHE {gamma}-ray sources with high-sensitivity X-ray instruments.

Funk, S.; /SLAC

2007-10-10T23:59:59.000Z

243

Predicted X-ray backgrounds for the International X-ray Observatory  

E-Print Network (OSTI)

The background that will be observed by IXO's X-ray detectors naturally separates into two components: (1) a Cosmic X-ray Background (CXB), primarily due to unresolved point sources at high energies (E>2 keV), along with ...

Bautz, Marshall W.

244

X-ray focal spot locating apparatus and method  

DOE Patents (OSTI)

An X-ray beam finder for locating a focal spot of an X-ray tube includes a mass of X-ray opaque material having first and second axially-aligned, parallel-opposed faces connected by a plurality of substantially identical parallel holes perpendicular to the faces and a film holder for holding X-ray sensitive film tightly against one face while the other face is placed in contact with the window of an X-ray head.

Gilbert, Hubert W. (Cedar Crest, NM)

1985-07-30T23:59:59.000Z

245

X-ray Pinhole Camera Measurements  

SciTech Connect

The development of the rod pinch diode [1] has led to high-resolution radiography for dynamic events such as explosive tests. Rod pinch diodes use a small diameter anode rod, which extends through the aperture of a cathode plate. Electrons borne off the aperture surface can self-insulate and pinch onto the tip of the rod, creating an intense, small x-ray source (Primary Pinch). This source has been utilized as the main diagnostic on numerous experiments that include high-value, single-shot events. In such applications there is an emphasis on machine reliability, x-ray reproducibility, and x-ray quality [2]. In tests with the baseline rod pinch diode, we have observed that an additional pinch (Secondary Pinch) occurs at the interface near the anode rod and the rod holder. This suggests that stray electrons exist that are not associated with the Primary Pinch. In this paper we present measurements on both pinches using an x-ray pinhole camera. The camera is placed downstream of the Primary Pinch at an angle of 60 with respect to the diode centerline. This diagnostic will be employed to diagnose x-ray reproducibility and quality. In addition, we will investigate the performance of hybrid diodes relating to the formation of the Primary and Secondary Pinches.

Nelson, D. S. [NSTec; Berninger, M. J. [NSTec; Flores, P. A. [NSTec; Good, D. E. [NSTec; Henderson, D. J. [NSTec; Hogge, K. W. [NSTec; Huber, S. R. [NSTec; Lutz, S. S. [NSTec; Mitchell, S. E. [NSTec; Howe, R. A. [NSTec; Mitton, C. V. [NSTec; Molina, I. [NSTec; Bozman, D. R. [SNL; Cordova, S. R. [SNL; Mitchell, D. R. [SNL; Oliver, B. V. [SNL; Ormond, E. C. [SNL

2013-07-01T23:59:59.000Z

246

Nonlinear X-ray Compton Scattering  

E-Print Network (OSTI)

X-ray scattering is a weak linear probe of matter. It is primarily sensitive to the position of electrons and their momentum distribution. Elastic X-ray scattering forms the basis of atomic structural determination while inelastic Compton scattering is often used as a spectroscopic probe of both single-particle excitations and collective modes. X-ray free-electron lasers (XFELs) are unique tools for studying matter on its natural time and length scales due to their bright and coherent ultrashort pulses. However, in the focus of an XFEL the assumption of a weak linear probe breaks down, and nonlinear light-matter interactions can become ubiquitous. The field can be sufficiently high that even non-resonant multiphoton interactions at hard X-rays wavelengths become relevant. Here we report the observation of one of the most fundamental nonlinear X-ray-matter interactions, the simultaneous Compton scattering of two identical photons producing a single photon at nearly twice the photon energy. We measure scattered...

Fuchs, Matthias; Chen, Jian; Ghimire, Shambhu; Shwartz, Sharon; Kozina, Michael; Jiang, Mason; Henighan, Thomas; Bray, Crystal; Ndabashimiye, Georges; Bucksbaum, P H; Feng, Yiping; Herrmann, Sven; Carini, Gabriella; Pines, Jack; Hart, Philip; Kenney, Christopher; Guillet, Serge; Boutet, Sebastien; Williams, Garth; Messerschmidt, Marc; Seibert, Marvin; Moeller, Stefan; Hastings, Jerome B; Reis, David A

2015-01-01T23:59:59.000Z

247

X-ray lithography using holographic images  

DOE Patents (OSTI)

Methods for forming X-ray images having 0.25 {micro}m minimum line widths on X-ray sensitive material are presented. A holographic image of a desired circuit pattern is projected onto a wafer or other image-receiving substrate to allow recording of the desired image in photoresist material. In one embodiment, the method uses on-axis transmission and provides a high flux X-ray source having modest monochromaticity and coherence requirements. A layer of light-sensitive photoresist material on a wafer with a selected surface is provided to receive the image(s). The hologram has variable optical thickness and variable associated optical phase angle and amplitude attenuation for transmission of the X-rays. A second embodiment uses off-axis holography. The wafer receives the holographic image by grazing incidence reflection from a hologram printed on a flat metal or other highly reflecting surface or substrate. In this second embodiment, an X-ray beam with a high degree of monochromaticity and spatial coherence is required. 15 figs.

Howells, M.S.; Jacobsen, C.

1997-03-18T23:59:59.000Z

248

Oscillations During Thermonuclear X-ray Bursts  

E-Print Network (OSTI)

High amplitude, nearly coherent X-ray brightness oscillations during thermonuclear X-ray bursts were discovered with the Rossi X-ray Timing Explorer (RXTE) in early 1996. Spectral and timing evidence strongly supports the conclusion that these oscillations are caused by rotational modulation of the burst emission and that they reveal the spin frequency of neutron stars in low mass X-ray binaries, a long sought goal of X-ray astronomy. Studies carried out over the past year have led to the discovery of burst oscillations in four new sources, bringing to ten the number with confirmed burst oscillations. I review the status of our knowledge of these oscillations and indicate how they can be used to probe the physics of neutron stars. For a few burst oscillation sources it has been proposed that the strongest and most ubiquitous frequency is actually the first overtone of the spin frequency and hence that two nearly antipodal hot spots are present on the neutron star. This inference has important implications for both the physics of thermonuclear burning as well as the mass - radius relation for neutron stars, so its confirmation is crucial. I discuss recent attempts to confirm this hypothesis for 4U 1636-53, the source for which a signal at the putative fundamental (290 Hz) has been claimed.

Tod E. Strohmayer

2001-01-12T23:59:59.000Z

249

X-ray lithography using holographic images  

DOE Patents (OSTI)

Methods for forming X-ray images having 0.25 .mu.m minimum line widths on X-ray sensitive material are presented. A holgraphic image of a desired circuit pattern is projected onto a wafer or other image-receiving substrate to allow recording of the desired image in photoresist material. In one embodiment, the method uses on-axis transmission and provides a high flux X-ray source having modest monochromaticity and coherence requirements. A layer of light-sensitive photoresist material on a wafer with a selected surface is provided to receive the image(s). The hologram has variable optical thickness and variable associated optical phase angle and amplitude attenuation for transmission of the X-rays. A second embodiment uses off-axis holography. The wafer receives the holographic image by grazing incidence reflection from a hologram printed on a flat metal or other highly reflecting surface or substrate. In this second embodiment, an X-ray beam with a high degree of monochromaticity and spatial coherence is required.

Howells, Malcolm S. (Berkeley, CA); Jacobsen, Chris (Sound Beach, NY)

1997-01-01T23:59:59.000Z

250

Cosmic rays and tests of fundamental principles  

E-Print Network (OSTI)

It is now widely acknowledged that cosmic rays experiments can test possible new physics directly generated at the Planck scale or at some other fundamental scale. By studying particle properties at energies far beyond the reach of any man-made accelerator, they can yield unique checks of basic principles. A well-known example is provided by possible tests of special relativity at the highest cosmic-ray energies. But other essential ingredients of standard theories can in principle be tested: quantum mechanics, uncertainty principle, energy and momentum conservation, effective space-time dimensions, hamiltonian and lagrangian formalisms, postulates of cosmology, vacuum dynamics and particle propagation, quark and gluon confinement, elementariness of particles... Standard particle physics or string-like patterns may have a composite origin able to manifest itself through specific cosmic-ray signatures. Ultra-high energy cosmic rays, but also cosmic rays at lower energies, are probes of both "conventional" and new Physics. Status, prospects, new ideas, and open questions in the field are discussed. The Post Scriptum shows that several basic features of modern cosmology naturally appear in a SU(2) spinorial description of space-time without any need for matter, relativity or standard gravitation. New possible effects related to the spinorial space-time structure can also be foreseen. Similarly, the existence of spin-1/2 particles can be naturally related to physics beyond Planck scale and to a possible pre-Big Bang era.

Luis Gonzalez-Mestres

2010-11-22T23:59:59.000Z

251

X-ray imaging crystal spectrometer for extended X-ray sources  

DOE Patents (OSTI)

Spherically or toroidally curved, double focusing crystals are used in a spectrometer for X-ray diagnostics of an extended X-ray source such as a hot plasma produced in a tokomak fusion experiment to provide spatially and temporally resolved data on plasma parameters using the imaging properties for Bragg angles near 45. For a Bragg angle of 45.degree., the spherical crystal focuses a bundle of near parallel X-rays (the cross section of which is determined by the cross section of the crystal) from the plasma to a point on a detector, with parallel rays inclined to the main plain of diffraction focused to different points on the detector. Thus, it is possible to radially image the plasma X-ray emission in different wavelengths simultaneously with a single crystal.

Bitter, Manfred L. (Princeton, NJ); Fraenkel, Ben (Jerusalem, IL); Gorman, James L. (Bordentown, NJ); Hill, Kenneth W. (Lawrenceville, NJ); Roquemore, A. Lane (Cranbury, NJ); Stodiek, Wolfgang (Princeton, NJ); von Goeler, Schweickhard E. (Princeton, NJ)

2001-01-01T23:59:59.000Z

252

GreenRay Inc | Open Energy Information  

Open Energy Info (EERE)

GreenRay Inc GreenRay Inc Jump to: navigation, search Name GreenRay Inc Place Westford, Massachusetts Zip 1886 Product US-based manufacturer of residential AC PV module system that integrates an inverter; still in development stage. Coordinates 44.614908°, -73.015053° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":44.614908,"lon":-73.015053,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

253

RayTracker Inc | Open Energy Information  

Open Energy Info (EERE)

RayTracker Inc RayTracker Inc Jump to: navigation, search Name RayTracker Inc. Place Pasadena, California Zip 91103 Sector Solar Product California-based maker of single-axis solar tracker systems. Coordinates 29.690847°, -95.196308° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":29.690847,"lon":-95.196308,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

254

SuperAGILE and Gamma Ray Bursts  

SciTech Connect

The solid-state hard X-ray imager of AGILE gamma-ray mission -- SuperAGILE -- has a six arcmin on-axis angular resolution in the 15-45 keV range, a field of view in excess of 1 steradian. The instrument is very light: 5 kg only. It is equipped with an on-board self triggering logic, image deconvolution, and it is able to transmit the coordinates of a GRB to the ground in real-time through the ORBCOMM constellation of satellites. Photon by photon Scientific Data are sent to the Malindi ground station at every contact. In this paper we review the performance of the SuperAGILE experiment (scheduled for a launch in the middle of 2006), after its first onground calibrations, and show the perspectives for Gamma Ray Bursts.

Pacciani, Luigi; Costa, Enrico; Del Monte, Ettore; Donnarumma, Immacolata; Evangelista, Yuri; Feroci, Marco; Frutti, Massimo; Lazzarotto, Francesco; Lapshov, Igor; Rubini, Alda; Soffitta, Paolo; Tavani, Marco [IASF-INAF Rome (Italy); Barbiellini, Guido [INFN Trieste (Italy); Mastropietro, Marcello [CNR Montelibretti (Italy); Morelli, Ennio [IASF-INAF-Bologna (Italy); Rapisarda, Massimo [ENEA Frascati (Italy)

2006-05-19T23:59:59.000Z

255

CAN ULTRAHIGH-ENERGY COSMIC RAYS COME FROM GAMMA-RAY BURSTS? COSMIC RAYS BELOW THE ANKLE AND GALACTIC GAMMA-RAY BURSTS  

SciTech Connect

The maximum cosmic-ray energy achievable by acceleration by a relativistic blast wave is derived. It is shown that forward shocks from long gamma-ray bursts (GRBs) in the interstellar medium accelerate protons to large enough energies, and have a sufficient energy budget, to produce the Galactic cosmic-ray component just below the ankle at 4 x 10{sup 18} eV, as per an earlier suggestion. It is further argued that, were extragalactic long GRBs responsible for the component above the ankle as well, the occasional Galactic GRB within the solar circle would contribute more than the observational limits on the outward flux from the solar circle, unless an avoidance scenario, such as intermittency and/or beaming, allows the present-day local flux to be less than 10{sup -3} of the average. Difficulties with these avoidance scenarios are noted.

Eichler, David [Physics Department, Ben-Gurion University, Be'er-Sheva 84105 (Israel); Pohl, Martin [Institut fuer Physik und Astronomie, Universitaet Potsdam, 14476 Potsdam-Golm (Germany)

2011-09-10T23:59:59.000Z

256

Fermi Observations of Gamma-ray Bursts  

SciTech Connect

The gamma-ray emission mechanism of Gamma-ray bursts (GRBs) are still unknown. Fermi Gamma-ray Space Telescope successfully detected high-energy (> 100 MeV) emission from 17 GRBs since its launch. Fermi revealed the distinct temporal behaviors and extra spectral component from high-energy emission. These new observational results are driving many theoretical implications, such as leptonic, hadronic and afterglow origin. The highest energy photon detected by Fermi gives a constraint on the bulk Lorentz factor of the ultra-relativistic jets of GRBs. The impact of the Fermi GRB observations extends not only to the GRB-related issues but also to the outside GRB physics, such as quantum gravity and model of the extra galactic background light.

Ohno, Masanori [Institute of Space and Astronautical Science, JAXA, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan)

2010-10-15T23:59:59.000Z

257

Can Ultrahigh-energy Cosmic Rays Come from Gamma-Ray Bursts? Cosmic Rays Below the Ankle and Galactic Gamma-Ray Bursts  

Science Journals Connector (OSTI)

The maximum cosmic-ray energy achievable by acceleration by a relativistic blast wave is derived. It is shown that forward shocks from long gamma-ray bursts (GRBs) in the interstellar medium accelerate protons to large enough energies, and have a sufficient energy budget, to produce the Galactic cosmic-ray component just below the ankle at 4 ? 1018 eV, as per an earlier suggestion. It is further argued that, were extragalactic long GRBs responsible for the component above the ankle as well, the occasional Galactic GRB within the solar circle would contribute more than the observational limits on the outward flux from the solar circle, unless an avoidance scenario, such as intermittency and/or beaming, allows the present-day local flux to be less than 103 of the average. Difficulties with these avoidance scenarios are noted.

David Eichler; Martin Pohl

2011-01-01T23:59:59.000Z

258

X-ray variability in M87  

E-Print Network (OSTI)

We present the evidence for X-ray variability from the core and from knot A in the M87 jet based on data from two observations with the Einstein Observatory High Resolution Imager (HRI) and three observations with the ROSAT HRI. The core intensity showed a 16% increase in 17 months ('79-'80); a 12% increase in the 3 years '92 to '95; and a 17% drop in the last half of 1995. The intensity of knot A appears to have decreased by 16% between 92Jun and 95Dec. Although the core variability is consistent with general expectations for AGN nuclei, the changes in knot A provide constraints on the x-ray emission process and geometry. Thus we predict that the x-ray morphology of knot A will differ significantly from the radio and optical structure.

D. E. Harris; J. A. Biretta; W. Junor

1996-12-05T23:59:59.000Z

259

Anomalous isotopic composition of cosmic rays  

SciTech Connect

Recent measurements of nonsolar isotopic patterns for the elements neon and (perhaps) magnesium in cosmic rays are interpreted within current models of stellar nucleosynthesis. One possible explanation is that the stars currently responsible for cosmic-ray synthesis in the Galaxy are typically super-metal-rich by a factor of two to three. Other possibilities include the selective acceleration of certain zones or masses of supernovas or the enhancement of /sup 22/Ne in the interstellar medium by mass loss from red giant stars and planetary nebulas. Measurements of critical isotopic ratios are suggested to aid in distinguishing among the various possibilities. Some of these explanations place significant constraints on the fraction of cosmic ray nuclei that must be fresh supernova debris and the masses of the supernovas involved. 1 figure, 3 tables.

Woosley, S.E.; Weaver, T.A.

1980-06-20T23:59:59.000Z

260

Displaced Vertices from X-ray Lines  

E-Print Network (OSTI)

We present a simple model of weak-scale thermal dark matter that gives rise to X-ray lines. Dark matter consists of two nearly degenerate states near the weak scale, which are populated thermally in the early universe via co-annihilation with slightly heavier states that are charged under the Standard Model. The X-ray line arises from the decay of the heavier dark matter component into the lighter one via a radiative dipole transition, at a rate that is slow compared to the age of the universe. The model predicts observable signatures at the LHC in the form of exotic events with missing energy and displaced leptons and jets. As an application, we show how this model can explain the recently observed 3.55 keV X-ray line.

Adam Falkowski; Yonit Hochberg; Joshua T. Ruderman

2014-09-09T23:59:59.000Z

Note: This page contains sample records for the topic "ray 202-586-5077 tosha" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

HETEROGENEITY IN SHORT GAMMA-RAY BURSTS  

SciTech Connect

We analyze the Swift/BAT sample of short gamma-ray bursts, using an objective Bayesian Block procedure to extract temporal descriptors of the bursts' initial pulse complexes (IPCs). The sample is comprised of 12 and 41 bursts with and without extended emission (EE) components, respectively. IPCs of non-EE bursts are dominated by single pulse structures, while EE bursts tend to have two or more pulse structures. The medians of characteristic timescales-durations, pulse structure widths, and peak intervals-for EE bursts are factors of {approx}2-3 longer than for non-EE bursts. A trend previously reported by Hakkila and colleagues unifying long and short bursts-the anti-correlation of pulse intensity and width-continues in the two short burst groups, with non-EE bursts extending to more intense, narrower pulses. In addition, we find that preceding and succeeding pulse intensities are anti-correlated with pulse interval. We also examine the short burst X-ray afterglows as observed by the Swift/X-Ray Telescope (XRT). The median flux of the initial XRT detections for EE bursts ({approx}6x10{sup -10} erg cm{sup -2} s{sup -1}) is {approx}>20x brighter than for non-EE bursts, and the median X-ray afterglow duration for EE bursts ({approx}60,000 s) is {approx}30x longer than for non-EE bursts. The tendency for EE bursts toward longer prompt-emission timescales and higher initial X-ray afterglow fluxes implies larger energy injections powering the afterglows. The longer-lasting X-ray afterglows of EE bursts may suggest that a significant fraction explode into denser environments than non-EE bursts, or that the sometimes-dominant EE component efficiently powers the afterglow. Combined, these results favor different progenitors for EE and non-EE short bursts.

Norris, Jay P. [Physics and Astronomy Department, University of Denver, Denver, CO 80208 (United States); Gehrels, Neil [Astroparticle Physics Laboratory, NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Scargle, Jeffrey D. [Space Science and Astrobiology Division, NASA/Ames Research Center, Moffett Field, CA 94035-1000 (United States)

2011-07-01T23:59:59.000Z

262

X-ray Science Division: Groups  

NLE Websites -- All DOE Office Websites (Extended Search)

Division: Groups Division: Groups Atomic, Molecular and Optical Physics (AMO) Primary Contact: Stephen Southworth Work focuses on understanding how strong optical and x-ray fields interact with matter, with an emphasis on photonic control of electronic, atomic and molecular motion. Chemical and Materials Science (CMS) Primary Contact: Randy Winans Research Disciplines: Chemistry, Materials Science Detectors (DET) Primary Contact: Antonino Miceli GMCA Structural Biology Facility (MX) Primary Contact: Robert Fischetti Research Disciplines: Biology, Life Sciences Imaging (IMG) Primary Contact: Francesco DeCarlo Research Disciplines: Materials Science, Biology, Physics, Life Sciences Inelastic X-ray & Nuclear Resonant Scattering (IXN) Primary Contact: Thomas Gog Research Disciplines: Condensed Matter Physics, Geophysics, Materials

263

Cosmology with X-ray Cluster Baryons  

SciTech Connect

X-ray cluster measurements interpreted with a universal baryon/gas mass fraction can theoretically serve as a cosmological distance probe. We examine issues of cosmological sensitivity for current (e.g., Chandra X-ray Observatory, XMM-Newton) and next generation (e.g., Con-X, XEUS) observations, along with systematic uncertainties and biases. To give competitive next generation constraints on dark energy, we find that systematics will need to be controlled to better than 1percent and any evolution in f_gas (and other cluster gas properties) must be calibrated so the residual uncertainty is weaker than (1+z)0.03.

Linder, Eric V.

2007-04-10T23:59:59.000Z

264

A supersymmetric model of gamma ray bursts  

E-Print Network (OSTI)

We propose a model for gamma ray bursts in which a star subject to a high level of fermion degeneracy undergoes a phase transition to a supersymmetric state. The burst is initiated by the transition of fermion pairs to sfermion pairs which, uninhibited by the Pauli exclusion principle, can drop to the ground state of minimum momentum through photon emission. The jet structure is attributed to the Bose statistics of sfermions whereby subsequent sfermion pairs are preferentially emitted into the same state (sfermion amplification by stimulated emission). Bremsstrahlung gamma rays tend to preserve the directional information of the sfermion momenta and are themselves enhanced by stimulated emission.

L. Clavelli; G. Karatheodoris

2005-08-08T23:59:59.000Z

265

Redshift indicators for gamma-ray bursts  

E-Print Network (OSTI)

The measure of the distances and luminosities of gamma-ray bursts (GRBs) led to the discovery that many GRB properties are strongly correlated with their intrinsic luminosity, leading to the construction of reliable luminosity indicators. These GRB luminosity indicators have quickly found applications, like the construction of 'pseudo-redshifts', or the measure of luminosity distances, which can be computed independently of the measure of the redshift. In this contribution I discuss various issues connected with the construction of luminosity-redshift indicators for gamma-ray bursts.

J-L. Atteia

2005-05-04T23:59:59.000Z

266

Phase recovery for x-ray crystallography  

Science Journals Connector (OSTI)

For many years people have believed that in conventional x-ray crystallography one can only record the diffraction intensities but not the phases. In order to obtain the atomic arrangements, one usually has to guess a structure and then fit the intensity data by refining its parameters. Here, we show that the phases are in fact hidden in the intensity data, and can be directly recovered from the peak profiles. This method is demonstrated by the normal two-beam x-ray diffraction of a noncentrosymmetric crystal, and nontrivial phases are recovered from the intensity data alone.

G. Xu, G. E. Zhou, and X. Y. Zhang

1999-04-01T23:59:59.000Z

267

Time-resolved x-ray diagnostics  

SciTech Connect

Techniques for time-resolved x-ray diagnostics will be reviewed with emphasis on systems utilizing x-ray diodes or scintillators. System design concerns for high-bandwidth (> 1 GHz) diagnostics will be emphasized. The limitations of a coaxial cable system and a technique for equalizing to improve bandwidth of such a system will be reviewed. Characteristics of new multi-GHz amplifiers will be presented. An example of a complete operational system on the Los Alamos Helios laser will be presented which has a bandwidth near 3 GHz over 38 m of coax. The system includes the cable, an amplifier, an oscilloscope, and a digital camera readout.

Lyons, P.B.

1981-01-01T23:59:59.000Z

268

Ultra-high energy cosmic rays, cascade gamma-rays, and high-energy neutrinos from gamma-ray bursts  

E-Print Network (OSTI)

Gamma-ray bursts (GRBs) are sources of energetic, highly variable fluxes of gamma rays, which demonstrates that they are powerful particle accelerators. Besides relativistic electrons, GRBs should also accelerate high-energy hadrons, some of which could escape cooling to produce ultra-high energy cosmic rays (UHECRs). Acceleration of high-energy hadrons in GRB blast waves will be established if high-energy neutrinos produced through photopion interactions in the blast wave are detected from GRBs. Limitations on the energy in nonthermal hadrons and the number of expected neutrinos are imposed by the fluxes from pair-photon cascades initiated in the same processes that produce neutrinos. Only the most powerful bursts at fluence levels >~ 3e-4 erg/cm^2 offer a realistic prospect for detection of >> TeV neutrinos. Detection of high-energy neutrinos is likely if GRB blast waves have large baryon loads and Doppler factors <~ 200. Cascade gamma rays will accompany neutrino production and might already have been detected as anomalous emission components in the spectra of some GRBs. Prospects for detection of GRBs in the Milky Way are also considered.

Charles D. Dermer; Armen Atoyan

2006-06-26T23:59:59.000Z

269

Ray-Strips: A Compact Mesh Representation for Interactive Ray Tracing Christian Lauterbach1 Sung-Eui Yoon2 Dinesh Manocha1  

E-Print Network (OSTI)

Ray-Strips: A Compact Mesh Representation for Interactive Ray Tracing Christian Lauterbach1 Sung-Eui

North Carolina at Chapel Hill, University of

270

Cosmological Gamma-Ray Bursts and the Highest Energy Cosmic Rays  

Science Journals Connector (OSTI)

We discuss a scenario in which the highest energy cosmic rays (CR's) and cosmological ?-ray bursts (GRB's) have a common origin. This scenario is consistent with the observed CR flux above 1020 eV, provided that each burst produces similar energies in ? rays and in CR's above 1020 eV. Protons may be accelerated by Fermi's mechanism to energies ?1020 eV in a dissipative, ultrarelativistic wind, with luminosity and Lorentz factor high enough to produce a GRB. For a homogeneous GRB distribution, this scenario predicts an isotropic, time-independent CR flux.

Eli Waxman

1995-07-17T23:59:59.000Z

271

Hard x-ray or gamma ray laser by a dense electron beam  

E-Print Network (OSTI)

A coherent x-ray or gamma ray can be created from a dense electron beam propagating through an intense laser undulator. It is analyzed by using the Landau damping theory which suits better than the conventional linear analysis for the free electron laser, as the electron beam energy spread is high. The analysis suggests that the currently available physical parameters would enable the generation of the coherent gamma ray of up to 100 keV. The electron quantum diffraction suppresses the FEL action, by which the maximum radiation energy to be generated is limited.

S. Son; S. J. Moon

2012-02-12T23:59:59.000Z

272

Rise Time Measurement for Ultrafast X-Ray Pulses  

DOE Patents (OSTI)

A pump-probe scheme measures the rise time of ultrafast x-ray pulses. Conventional high speed x-ray diagnostics (x-ray streak cameras, PIN diodes, diamond PCD devices) do not provide sufficient time resolution to resolve rise times of x-ray pulses on the order of 50 fs or less as they are being produced by modern fast x-ray sources. Here, we are describing a pump-probe technique that can be employed to measure events where detector resolution is insufficient to resolve the event. The scheme utilizes a diamond plate as an x-ray transducer and a p-polarized probe beam.

Celliers, Peter M.; Weber, Franz A.; Moon, Stephen J.

2005-04-05T23:59:59.000Z

273

X-ray microscopy using grazing-incidence reflection optics  

SciTech Connect

The Kirkpatrick-Baez microscopes are described along with their role as the workhorse of the x-ray imaging devices. This role is being extended with the development of a 22X magnification Kirkpatrick-Baez x-ray microscope with multilayer x-ray mirrors. These mirrors can operate at large angles, high x-ray energies, and have a narrow, well defined x-ray energy bandpass. This will make them useful for numerous experiments. However, where a large solid angle is needed, the Woelter microscope will still be necessary and the technology needed to build them will be useful for many other types of x-ray optics.

Price, R.H.

1981-08-06T23:59:59.000Z

274

Sharper Focusing of Hard X-rays  

NLE Websites -- All DOE Office Websites (Extended Search)

Sharper Focusing of Hard X-rays FROM: Physics News Update Number 773 #1, April 12, 2006, by Phil Schewe and Ben Stein Note: This text has been slightly modified from the original. Sharper focusing of hard x-rays has been achieved with a device developed at Argonne National Lab. Because of their high energy, x-rays are hard to focus: they can be reflected from a surface but only at a glancing angle (less than a tenth of a degree); they can be refracted but the index of refraction is very close to 1, so that making efficient lenses becomes a problem; and they can be diffracted, but the relatively thick, variable pitch grating required for focusing is tricky to achieve. The Argonne device is of the diffraction type, and it consists of a stack of alternating layers of metal and silicon, made by depositing progressively thicker layers. When the x-rays fall on such a structure, nearly edge-on, what they see is a grating (called a linear zone plate) consisting of a sort of bar-code pattern.

275

Energy spectrum of cosmic-ray muons  

Science Journals Connector (OSTI)

The energy spectrum of cosmic-ray muons at sea-level is calculated by the ... in good agreement with the observed data of muons with the zenith angles of 0 and ... the scaling model is valid up to the muon energy

H. Komori; K. Mitsui

276

Radioactive Thulium for X-Rays  

Science Journals Connector (OSTI)

Radioactive power from thulium makes Argonne x-ray unit a potential for medical and industrial use ... Active component of the instrument is a tiny particle (one-fifth gram) of thulium-170 which has been made radioactive in a heavy water nuclear reactor at Arco, Idaho. ...

1954-05-03T23:59:59.000Z

277

HYPERNUCLEAR STRUCTURE FROM GAMMA-RAY SPECTROSCOPY.  

SciTech Connect

The energies of p-shell hypernuclear {gamma} rays obtained from recent experiments using the Hyperball at BNL and KEK are used to constrain the YN interaction which enters into shell-model calculations which include both {Lambda} and {Sigma} configurations.

MILLENER,D.J.

2003-10-14T23:59:59.000Z

278

X-ray spectroscopy of manganese clusters  

SciTech Connect

Much of this thesis represents the groundwork necessary in order to probe Mn clusters more productively than with conventional Mn K-edge XAS and is presented in Part 1. Part 2 contains the application of x-ray techniques to Mn metalloproteins and includes a prognosis at the end of each chapter. Individual Mn oxidation states are more readily distinguishable in Mn L-edge spectra. An empirical mixed valence simulation routine for determining the average Mn oxidation state has been developed. The first Mn L-edge spectra of a metalloprotein were measured and interpreted. The energy of Mn K{beta} emission is strongly correlated with average Mn oxidation state. K{beta} results support oxidation states of Mn(III){sub 2}(IV){sub 2} for the S{sub 1} state of Photosystem II chemical chemically reduced preparations contain predominantly Mn(II). A strength and limitation of XAS is that it probes all of the species of a particular element in a sample. It would often be advantageous to selectively probe different forms of the same element. The first demonstration that chemical shifts in x-ray fluorescence energies can be used to obtain oxidation state-selective x-ray absorption spectra is presented. Spin-dependent spectra can also be used to obtain a more simplified picture of local structure. The first spin-polarized extended x-ray absorption fine structure using Mn K{beta} fluorescence detection is shown.

Grush, M.M. [Univ. of California, Davis, CA (United States). Dept. of Applied Science; [Lawrence Berkeley National Lab., CA (United States). Energy and Environment Div.

1996-06-01T23:59:59.000Z

279

Accelerator Data for Cosmic Ray Physics  

E-Print Network (OSTI)

I present selected examples of accelerator data, mainly from hadron colliders, that are relevant for understanding cosmic ray showers. I focus on the forward region, $x_{Feynman} > 0.05$, where high energy data are scarce, since the emphasis in collider physics became high-$p_T$ phenomena.

M. G. Albrow

2010-09-21T23:59:59.000Z

280

Multiple wavelength X-ray monochromators  

DOE Patents (OSTI)

An improved apparatus and method is provided for separating input x-ray radiation containing first and second x-ray wavelengths into spatially separate first and second output radiation which contain the first and second x-ray wavelengths, respectively. The apparatus includes a crystalline diffractor which includes a first set of parallel crystal planes, where each of the planes is spaced a predetermined first distance from one another. The crystalline diffractor also includes a second set of parallel crystal planes inclined at an angle with respect to the first set of crystal planes where each of the planes of the second set of parallel crystal planes is spaced a predetermined second distance from one another. In one embodiment, the crystalline diffractor is comprised of a single crystal. In a second embodiment, the crystalline diffractor is comprised of a stack of two crystals. In a third embodiment, the crystalline diffractor includes a single crystal that is bent for focusing the separate first and second output x-ray radiation wavelengths into separate focal points. 3 figs.

Steinmeyer, P.A.

1992-11-17T23:59:59.000Z

Note: This page contains sample records for the topic "ray 202-586-5077 tosha" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Catching the highest energy cosmic rays  

Science Journals Connector (OSTI)

......interest in very-high-energy cosmic rays, which I define arbitrarily as those of energies above 3 1018 eV, the devices...Pierre Auger Observatory in Argentina - and what has been deduced...the measurements of the energy spectrum and arrival directions......

Alan A Watson

2009-04-01T23:59:59.000Z

282

Soft x-ray laser microscope  

SciTech Connect

The program consisted of two phases (Phase I and Phase II). The goal of the Phase I (first year program) was to design and construct the Soft X-ray Laser Contact Microscope. Such microscope was constructed and adapted to PPL's 18.2nm soft X-ray Laser (SXL), which in turn was modified and prepared for microscopy experiments. Investigation of the photoresist response to 18.2nm laser radiation and transmissivity of 0.1m thick silicion-nitride (Si[sub 3]N[sub 4]) windows were important initial works. The goal of the first year of Phase II was to construct X-ray contact microscope in combination with existing optical phase microscope, already used by biologists. In the second year of Phase II study of dehydrated Horeseshoe Crab and Hela cancer cells were performed with COXRALM. Also during Phase II, the Imaging X-Ray Laser Microscope (IXRALM) was designed and constructed. This paper describes the development of each of the microscopes and their application for research.

Suckewer, P.I.

1990-10-01T23:59:59.000Z

283

Small Angle X-Ray Scattering Detector  

DOE Patents (OSTI)

A detector for time-resolved small-angle x-ray scattering includes a nearly constant diameter, evacuated linear tube having an end plate detector with a first fluorescent screen and concentric rings of first fiber optic bundles for low angle scattering detection and an annular detector having a second fluorescent screen and second fiber optic bundles concentrically disposed about the tube for higher angle scattering detection. With the scattering source, i.e., the specimen under investigation, located outside of the evacuated tube on the tube's longitudinal axis, scattered x-rays are detected by the fiber optic bundles, to each of which is coupled a respective photodetector, to provide a measurement resolution, i.e., dq/q, where q is the momentum transferred from an incident x-ray to an x-ray scattering specimen, of 2% over two (2) orders of magnitude in reciprocal space, i.e., q.sub.max /q.sub.min.congruent.100.

Hessler, Jan P. (Downers Grove, IL)

2004-06-15T23:59:59.000Z

284

Gamma-Ray Bursts: Restarting the Engine  

Science Journals Connector (OSTI)

Recent gamma-ray burst observations have revealed late-time, highly energetic events that deviate from the simplest expectations of the standard fireball picture. Instead, they may indicate that the central engine is active or restarted at late times. We suggest that fragmentation and subsequent accretion during the collapse of a rapidly rotating stellar core offers a natural mechanism for this.

Andrew King; Paul T. O'Brien; Michael R. Goad; Julian Osborne; Emma Olsson; Kim Page

2005-01-01T23:59:59.000Z

285

Political Science Ray V. Christensen, Chair  

E-Print Network (OSTI)

Political Science Ray V. Christensen, Chair 745 SWKT, (801) 422-5133 College of Family, Home programs in the Department of Political Science are open enrollment. The Discipline The political science in all things." Politics extends far beyond the immediate concerns of politicians or pollsters

Hart, Gus

286

SLAC All Access: X-ray Microscope  

ScienceCinema (OSTI)

SLAC physicists Johanna Nelson and Yijin Liu give a brief overview of the X-ray microscope at the Stanford Synchrotron Radiation Lightsource (SSRL) that is helping improve rechargeable-battery technology by letting researchers peek into the inner workings of batteries as they operate.

Nelson, Johanna; Liu, Yijin

2014-06-13T23:59:59.000Z

287

John Ray in Italy: lost manuscripts rediscovered  

Science Journals Connector (OSTI)

...discovered manuscripts but also throw light on the way in which Ray's...other edibles. /p. 25/ About Christmas time it is the fashion all over...all the feathers are of a light crimson very pleasant colour...the two men or it may throw light on the nature of the tours that...

2014-01-01T23:59:59.000Z

288

Student Projects in Cosmic Ray Detection  

Science Journals Connector (OSTI)

The Alberta Large?area Time?coincidence Array (ALTA) study has been in existence for about 10 years under the direction of Jim Pinfold of the Centre for Particle Physics at the University of Alberta.1 The purpose of the ALTA project is to involve Alberta high schools and primarily their physics classes to assist in the detection of the presence of cosmic ray bursts in different Alberta locations. These cosmic rays involve highspeed elementary particles many from far outside our solar system and even from outside our galaxy. These particles collide with the particles in our atmosphere break up these molecules into rather exotic elementary particles which often reach the surface of the Earth and can be detected by fairly simple equipment. One of the objectives of ALTA is to determine the nature of some of the most energetic cosmic ray particles whose origin is still not known. Recently 2the Pierre Auger Collaboration has confirmed that the highest energy cosmic rays appear to be coming from nearby galaxies. The mechanism for their production is still not well understood.

W. Brouwer; J. Pinfold; R. Soluk; B. McDonough; V. Pasek; Zheng Bao?shan

2009-01-01T23:59:59.000Z

289

Neutrino Balls and Gamma-Ray Bursts  

E-Print Network (OSTI)

We propose a mechanism by which the neutrino emission from a supernova-type explosion can be converted into a gamma-ray burst of total energy $\\sim 10^{50}$ ergs. This occurs naturally if the explosion is situated inside a ball of trapped neutrinos, which in turn may lie at a galactic core. There are possible unique signatures of this scenario.

B. Holdom; R. A. Malaney

1993-06-17T23:59:59.000Z

290

Doppler Effect in Positive Rays of Hydrogen  

Science Journals Connector (OSTI)

... THE Balmer lines in the spectra of the positive rays of hydrogen show Doppler displacement d? given by the relation where ? is the wave-length of the light ... of light. J. Stark1, and J. Stark and Steubing2 showed that whereas the Doppler displacement is not a line but a strip of finite width, the maximum displacement ...

B. DASANNACHARYA; G. K. DAS

1944-07-01T23:59:59.000Z

291

Ray tracing in anisotropic media with singularities  

Science Journals Connector (OSTI)

......the slowness vector with the spherical angles 45 and theta54.74...singularity, the ray can be bent significantly even if the velocity...Elastic waves in triclinic crystals. Topology of polarization...stability in elastic wave theory in crystals, J. Exper. Theor. Phys......

Vclav Vavry?uk

2001-04-01T23:59:59.000Z

292

X-ray imaging, spacecraft nuclear fission and cosmic ray contraband  

NLE Websites -- All DOE Office Websites (Extended Search)

R&D 100 Awards winners R&D 100 Awards winners X-ray imaging, spacecraft nuclear fission and cosmic ray contraband detection score R&D 100 awards R&D Magazine announced the winners and three technologies from Los Alamos National Laboratory and its partners are among the honorees. July 8, 2013 MiniMAX is a battery powered, digital x-ray imaging system that is completely self-contained, lightweight, compact and portable. MiniMAX is a battery powered, digital x-ray imaging system that is completely self-contained, lightweight, compact and portable. Contact Nancy Ambrosiano Communications Office (505) 667-0471 Email "The innovation and creativity shown in this year's awards is truly inspiring. It gives me great confidence in the Laboratory's intellectual vitality and ongoing role in national security science. Congratulations to

293

Observations of cosmic gamma ray sources and their contribution to the diffuse gamma ray background  

SciTech Connect

The objective is to study soft gamma ray emission in the 0.1 to 10 MeV energy band for selected active galactic nuclei and explore how much they contribute to the total diffuse gamma ray background. A series of imaging observations of extragalactic objects in the low energy gamma-ray region were carried out by the Coded Aperture Directional Gamma-ray Telescope (DGT). The DGT was successfully flown at stratospheric balloon altitudes, and observations were made of the Crab, NGC 1275, MKN 421, and NGC 4151. The measured Crab spectrum is consistent with a featureless power-law of the form. Significant emission was detected up to 500 keV from the Seyfert galaxy, NGC 4151. To increase the total sky exposure the extragalactic field images were analyzed, including the 3C 273 region, obtained by the DGT.

Bhattacharya, D.

1990-01-01T23:59:59.000Z

294

On the spectrum of Ultrahigh Energy Cosmic Rays and the Gamma Ray Burst Origin Hypothesis  

E-Print Network (OSTI)

It has been suggested that cosmological gamma-ray bursts (GRBs) can produce the observed flux of cosmic rays at the highest energies. However, recent studies of GRBs indicate that their redshift distribution likely follows that of the average star formation rate and that GRBs were more numerous at high redshifts. As a consequence, we show that photomeson production energy losses suffered by ultrahigh energy cosmic rays coming from GRBs would produce too sharp a spectral high energy cutoff to be consistent with the air shower data. Furthermore, we show that cosmological GRBs fail to supply the energy input required to account for the cosmic ray flux above 10 EeV by a factor of 100-1000.

S. T. Scully; F. W. Stecker

2000-06-08T23:59:59.000Z

295

Synchrotron x-ray fluorescence and extended x-ray absorption fine structure analysis  

SciTech Connect

The advent of dedicated synchrotron radiation sources has led to a significant increase in activity in many areas of science dealing with the interaction of x-rays with matter. Synchrotron radiation provides intense, linearly polarized, naturally collimated, continuously tunable photon beams, which are used to determine not only the elemental composition of a complex, polyatomic, dilute material but also the chemical form of the elements with improved accuracy. Examples of the application of synchrotron radiation include experiments in synchrotron x-ray fluorescence (SXRF) analysis and extended x-ray absorption fine structure (EXAFS) analysis. New synchrotron radiation x-ray microprobes for elemental analysis in the parts per billion range are under construction at several laboratories. 76 references, 24 figures.

Chen, J.R.; Gordon, B.M.; Hanson, A.L.; Jones, K.W.; Kraner, H.W.; Chao, E.C.T.; Minkin, J.A.

1984-01-01T23:59:59.000Z

296

X-RAY POINT-SOURCE POPULATIONS CONSTITUTING THE GALACTIC RIDGE X-RAY EMISSION  

SciTech Connect

Apparently diffuse X-ray emission has been known to exist along the central quarter of the Galactic Plane since the beginning of X-ray astronomy; this is referred to as the Galactic Ridge X-ray emission (GRXE). Recent deep X-ray observations have shown that numerous X-ray point sources account for a large fraction of the GRXE in the hard band (2-8 keV). However, the nature of these sources is poorly understood. Using the deepest X-ray observations made in the Chandra bulge field, we present the result of a coherent photometric and spectroscopic analysis of individual X-ray point sources for the purpose of constraining their nature and deriving their fractional contributions to the hard-band continuum and Fe K line emission of the GRXE. Based on the X-ray color-color diagram, we divided the point sources into three groups: A (hard), B (soft and broad spectrum), and C (soft and peaked spectrum). The group A sources are further decomposed spectrally into thermal and non-thermal sources with different fractions in different flux ranges. From their X-ray properties, we speculate that the group A non-thermal sources are mostly active galactic nuclei and the thermal sources are mostly white dwarf (WD) binaries such as magnetic and non-magnetic cataclysmic variables (CVs), pre-CVs, and symbiotic stars, whereas the group B and C sources are X-ray active stars in flares and quiescence, respectively. In the log N-log S curve of the 2-8 keV band, the group A non-thermal sources are dominant above Almost-Equal-To 10{sup -14} erg cm{sup -2} s{sup -1}, which is gradually taken over by Galactic sources in the fainter flux ranges. The Fe K{alpha} emission is mostly from the group A thermal (WD binaries) and the group B (X-ray active stars) sources.

Morihana, Kumiko [Institute of Physical and Chemical Research (RIKEN), 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan)] [Institute of Physical and Chemical Research (RIKEN), 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Tsujimoto, Masahiro; Ebisawa, Ken [Japan Aerospace Exploration Agency, Institute of Space and Astronautical Science, 3-1-1 Yoshino-dai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan)] [Japan Aerospace Exploration Agency, Institute of Space and Astronautical Science, 3-1-1 Yoshino-dai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan); Yoshida, Tessei, E-mail: morihana@crab.riken.jp [National Astronomical Observatory of Japan, 2-21-1, Osawa, Mitaka, Tokyo 181-8588 (Japan)] [National Astronomical Observatory of Japan, 2-21-1, Osawa, Mitaka, Tokyo 181-8588 (Japan)

2013-03-20T23:59:59.000Z

297

Beyond hard x-ray photoelectron spectroscopy: Simultaneous combination with x-ray diffraction  

SciTech Connect

Hard x-ray photoelectron spectroscopy (HAXPES) is a powerful and novel emerging technique for the nondestructive determination of electronic properties and chemical composition of bulk, buried interfaces and surfaces. It benefits from the exceptionally large escape depth of high kinetic energy photoelectrons, increasing the information depth up to several tens of nanometers. Complementing HAXPES with an atomic structure sensitive technique (such as x-ray diffraction) opens a new research field with major applications for materials science. At SpLine, the Spanish CRG beamline at the European Synchrotron Radiation Facility, we have developed a novel experimental set-up that combines HAXPES and x-ray diffraction (x-ray reflectivity, surface x-ray diffraction, grazing incidence x-ray diffraction, and reciprocal space maps). Both techniques can be operated simultaneously on the same sample and using the same excitation source. The set-up includes a robust 2S + 3D diffractometer hosting a ultrahigh vacuum chamber equipped with a unique photoelectron spectrometer (few eV < electron kinetic energy < 15 keV), x-ray tube (Mg/Ti), 15 keV electron gun, and auxiliary standard surface facilities (molecular beam epitaxy evaporator, ion gun, low energy electron diffraction, sample heating/cooling system, leak valves, load-lock sample transfer, etc.). This end-station offers the unique possibility of performing simultaneous HAXPES + x-ray diffraction studies. In the present work, we describe the experimental set-up together with two experimental examples that emphasize its outstanding capabilities: (i) nondestructive characterization of the Si/Ge and HfO{sub 2}/SiO{sub 2} interfaces on Ge-based CMOS devices, and (ii) strain study on La{sub 0.7}Ca{sub 0.3}MnO{sub 3} ultrathin films grown on SrTiO{sub 3}(001) substrate.

Rubio-Zuazo, Juan; Castro, German R. [SpLine, Spanish CRG beamline at the European Synchrotron Radiation Facility, B.P. 220, F-38043 Grenoble (France) and ICMM-CSIC Cantoblanco, E-28049 Madrid (Spain)

2013-05-15T23:59:59.000Z

298

A simple technique for gamma ray and cosmic ray spectroscopy using plastic scintillator  

E-Print Network (OSTI)

A new and simple technique has been developed using plastic scintillator detectors for gamma ray and cosmic ray spectroscopy without single channel analyzer (SCA) or multichannel analyzer (MCA). In these experiments only a leading edge discriminator (LED) and NIM scalers have been used. Energy calibration of gamma spectra in plastic scintillators has been done using Co$^{60}$ and Cs$^{137}$ sources. The details experimental technique, analysis procedure and experimental results has been presented in this article.

Akhilesh P. Nandan; Sharmili Rudra; Himangshu Neog; S. Biswas; S. Mahapatra; B. Mohanty; P. K. Samal

2014-12-30T23:59:59.000Z

299

Observation of the Crab Nebula in Soft Gamma Rays with the Nuclear Compton Telescope  

E-Print Network (OSTI)

Gamma-ray bursts . . . . . . . . . . . . . . . . . . . 1.268] G. J. Fishman. The gamma-ray burst capabilities of BATSEOlson. Observations of Gamma- Ray Bursts of Cosmic Origin.

Bandstra, Mark ShenYu

2010-01-01T23:59:59.000Z

300

E-Print Network 3.0 - assumed cosmic ray-modulated Sample Search...  

NLE Websites -- All DOE Office Websites (Extended Search)

Morphology of Anomalous Cosmic Rays in the Outer Heliosphere Summary: ray transport equation describes the physics of cosmic ray modulation in the heliosphere... in this equation...

Note: This page contains sample records for the topic "ray 202-586-5077 tosha" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

High Energy Gamma-Ray Emission from Gamma-Ray Bursts - Before GLAST  

SciTech Connect

Gamma-ray bursts (GRBs) are short and intense emission of soft {gamma}-rays, which have fascinated astronomers and astrophysicists since their unexpected discovery in 1960s. The X-ray/optical/radio afterglow observations confirm the cosmological origin of GRBs, support the fireball model, and imply a long-activity of the central engine. The high-energy {gamma}-ray emission (> 20 MeV) from GRBs is particularly important because they shed some lights on the radiation mechanisms and can help us to constrain the physical processes giving rise to the early afterglows. In this work, we review observational and theoretical studies of the high-energy emission from GRBs. Special attention is given to the expected high-energy emission signatures accompanying the canonical early-time X-ray afterglow that was observed by the Swift X-ray Telescope. We also discuss the detection prospect of the upcoming GLAST satellite and the current ground-based Cerenkov detectors.

Fan, Yi-Zhong; Piran, Tsvi

2011-11-29T23:59:59.000Z

302

Ultra High Energy Cosmic Rays and Gamma Ray Bursts from Axion Stars  

E-Print Network (OSTI)

We propose a model in which ultra high energy cosmic rays and gamma ray bursts are produced by collisions between neutron stars and axion stars. The acceleration of such a cosmic ray is made by the electric field, $\\sim 10^{15} (B/10^{12} {G}) {eV} {cm}^{-1}$, which is induced in an axion star by relatively strong magnetic field $B>10^{12}$ G of a neutron star. On the other hand, similar collisions generate gamma ray bursts when magnetic field is relatively small, e.g. $\\leq 10^{10}$ G. Assuming that the axion mass is $\\sim 10^{-9}$ eV, we can explain huge energies of the gamma ray bursts $\\sim 10^{54}$ erg as well as the ultra high energies of the cosmic rays $\\sim 10^{20}$ eV. We estimate rate of energy release in the collisions and we find that the rate roughly agrees with observations. In addition, we show that these axion stars are plausible candidates for MACHOs. Since the axion star induces oscillating electric current under the magnetic field, observable monochromatic radiations are emitted.

Aiichi Iwazaki

2000-08-29T23:59:59.000Z

303

The Animated Gamma-ray Sky Revealed by the Fermi Gamma-ray Space Telescope  

ScienceCinema (OSTI)

The Fermi Gamma-ray Space Telescope has been observing the sky in gamma-rays since August 2008. In addition to breakthrough capabilities in energy coverage (20 MeV-300 GeV) and angular resolution, the wide field of view of the Large Area Telescope enables observations of 20% of the sky at any instant, and of the whole sky every three hours. It has revealed a very animated sky with bright gamma-ray bursts flashing and vanishing in minutes, powerful active galactic nuclei flaring over hours and days, many pulsars twinkling in the Milky Way, and X-ray binaries shimmering along their orbit. Most of these variable sources had not been seen by the Fermi predecessor, EGRET, and the wealth of new data already brings important clues to the origin of the high-energy emission and particles powered by the compact objects. The telescope also brings crisp images of the bright gamma-ray emission produced by cosmic-ray interactions in the interstellar medium, thus allowing to measure the cosmic nuclei and electron spectra across the Galaxy, to weigh interstellar clouds, in particular in the dark-gas phase. The telescope sensitivity at high energy will soon provide useful constraints on dark-matter annihilations in a variety of environments. I will review the current results and future prospects of the Fermi mission.

Isabelle Grenier

2010-01-08T23:59:59.000Z

304

X-ray holography at Lawrence Livermore National Laboratory  

SciTech Connect

The x-ray holography program at the Lawrence Livermore National Laboratory has two principal goals: (1) the development of x-ray diffraction techniques for DNA sequence analysis and (2) the development of x-ray laser holography for structural analysis of intact biological cells and organelles. DNA sequence analysis will be accomplished by applying x-ray diffraction techniques to determine the ensemble average of the sequence of labels along the individual elements of crystalline DNA. X-ray laser holographic imaging will be accomplished by applying three dimensional x-ray holography to elucidate the structure of few hundred angstrom objects such as 300 {Angstrom} chromatin fibers, nuclear pores and nucleic acid replication complexes in living cells. Existing laboratory x-ray lasers will be utilized to produce flash x-ray holograms of the biological structures.

Trebes, J.; Annese, C.; Birdsall, D.; Brase, J.; Gray, J.; Lane, S.; London, R.; Matthews, D.; Peters, D.; Pinkel, D.; Stone, G.; Rapp, D.; Rosen, M.; Weier, U.; Yorkey, T.

1990-10-11T23:59:59.000Z

305

Detection of pseudo gamma-ray bursts of long duration  

Science Journals Connector (OSTI)

It is known that the counting rate of both Nai and Csi hard X-ray detectors can have intense enhancements of brief ... duration, which appear like very short cosmic gamma-ray bursts but probably are due to phosph...

F. Frontera; F. Fuligni; E. Morelli; G. Pizzichini

1981-03-01T23:59:59.000Z

306

Y-12s Training and Technology ? TAT and John Ray  

NLE Websites -- All DOE Office Websites (Extended Search)

young student to attend TAT. Here is John Ray"s story: "I was a graduate of the Union Carbide Y-12 based Training and Technology Program in 1978. My family moved to Oak Ridge in...

307

X-Ray Diffraction Microscopy of Magnetic Structures  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Diffraction Microscopy of Magnetic Structures Print science brief icon Scientists working at ALS Beamline 12.0.2.2 have demonstrated a new x-ray technique for producing...

308

-ray Irradiation Enhanced Boron-10 Compound Accumulation in Murine Tumors  

Science Journals Connector (OSTI)

......gamma-ray Irradiation Enhanced Boron-10 Compound Accumulation in Murine Tumors...effects of gamma-ray irradiation on boron-10 compound accumulation in a murine...sodium) administration. Then, the boron-10 concentrations in tumor and normal......

Yong Liu; Kenji Nagata; Shin-ichiro Masunaga; Minoru Suzuki; Genro Kashino; Yuko Kinashi; Hiroki Tanaka; Yoshinori Sakurai; Akira Maruhashi; Koji Ono

2009-11-01T23:59:59.000Z

309

X-ray diffraction study of zirconia pillared clays  

Science Journals Connector (OSTI)

X-ray powder diffraction (XRPD) and X-ray radial electronic distribution density (RED) of initial and zirconia-pillared interlayered clays (Zr-PILC) were studied. After pillaring, the basal ... under air to 17.7 ...

D.A. Zyuzin; E.M. Moroz; T.G. Kuznetsova

2004-01-01T23:59:59.000Z

310

Development of a Schwarzschild-type x-ray microscope  

Science Journals Connector (OSTI)

A Schwarzschild-type x-ray microscope has been designed, constructed, and tested. Ni/C multilayers were used as the x-ray mirrors, with a thickness (2d) of 7 nm and 30 layer pairs. The...

Kado, M; Yamashita, K; Ohtani, M; Tanaka, K A; Kodama, R; Kitamoto, S; Yamanaka, T; Nakai, S

1991-01-01T23:59:59.000Z

311

Biological Imaging by Soft X-Ray Diffraction Microscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Biological Imaging by Soft X-Ray Diffraction Microscopy Print Electron and x-ray microscopes are a valuable tool for both the life and materials sciences, but they are limited in...

312

A Record Run for the APS X-ray Source  

NLE Websites -- All DOE Office Websites (Extended Search)

2004 | 2003 | 2002 | 2001 2000 Subscribe to APS News rss feed A Record Run for the APS X-ray Source FEBRUARY 23, 2012 Bookmark and Share The APS storage ring. X-ray beams and...

313

Resonant Soft X-Ray Scattering - Combining Structural with Spectroscop...  

NLE Websites -- All DOE Office Websites (Extended Search)

Resonant Soft X-Ray Scattering - Combining Structural with Spectroscopic Refinement Friday, September 28, 2012 - 10:00am SLAC, Bldg. 137, Room 322 SSRL Presents Kevin Stone X-ray...

314

Can Ultrahigh Energy Cosmic Rays Come from Gamma-Ray Bursts? II: Cosmic Rays Below the Ankle and Galactic GRB  

E-Print Network (OSTI)

The maximum cosmic ray energy achievable by acceleration by a relativistic blast wave is derived. It is shown that forward shocks from long GRB in the interstellar medium are powerful enough to produce the Galactic cosmic-ray component up to the ankle at $4\\times 10^{18}$eV, as per an earlier suggestion (Levinson and Eichler, 1993). It is further argued that, were extragalactic long GRB responsible for the component {\\it above} the ankle as well, the contribution from an occasional Galactic GRB within the solar circle would yield more than the observational limits on the outward flux from the solar circle, unless intermittency and/or beaming causes the present-day contribution to be less than $10^{-3}$ times the time average, and difficulties with these avoidance scenarios are also noted.

Eichler, David

2011-01-01T23:59:59.000Z

315

A Gamma-Ray Bursts Fluence-Duration Correlation  

E-Print Network (OSTI)

durations of gamma-ray bursts, and provide arguments that this reflects a correlation between the total

Istvn Horvth; Lajos G. Balzs; Peter Mszros; Zsolt Bagoly

2005-01-01T23:59:59.000Z

316

Applications of holography to x-ray imaging  

SciTech Connect

In this paper we consider various applications of holographic techniques to the problem of soft x-ray imaging. We give special attention to imaging biological material using x-rays in the wavelength range 24 to 45A. We describe some experiments on formation and reconstruction of x-ray holograms and propose some ways in which holographic techniques might contribute to the difficult problem of fabricating optical elements for use in the soft x-ray region.

Howells, M.; Iarocci, M.; Kenney, J.; Rarback, H.; Rosser, R.; Yun, W.

1985-03-01T23:59:59.000Z

317

Applications of holography to X-ray imaging  

SciTech Connect

In this paper the authors consider various applications of holographic techniques to the problem of soft x-ray imaging. Special attention is given to imaging biological material using x-rays in the wavelength range 24-45A. The authors describe some experiments on formation and reconstruction of x-ray holograms and propose some ways in which holographic techniques might contribute to the difficult problem of fabricating optical elements for use in the soft x-ray region.

Howells, M.; Iarocci, M.; Kenney, J.; Rarback, H.; Rosser, R.; Yun, W.

1985-01-01T23:59:59.000Z

318

X-ray MicroCT Training Presentation  

E-Print Network (OSTI)

X-ray MicroCT Training Presentation T. Fettah Kosar, PhD Center for Nanoscale Systems Harvard) Model: HMXST225 (max. 225 kV) #12;Overview 3 Introduction to X-ray imaging and Computed Tomography (CT) · What are X-rays and how do we generate and image them? · How do we magnify X-ray images and keep them

319

X-ray Microscopy and Imaging: 2-BM  

NLE Websites -- All DOE Office Websites (Extended Search)

BM BM Introduction The 2-BM beamline offers measurement capabilities for x-ray microtomography, x-ray topography and x-ray microdiffraction. X-ray microtomography and x-ray diffraction instruments are installed on separate optical tables for independent operation with fast switch over time. Optically-coupled high-resolution CCD system is used for microtomography and topography with up to 1 micron spatial resolution. X-ray microdiffraction setup consists of KB microfocussing mirrors (~3 micron minimum spot), four-circle Huber diffractometer, high-precision translation sample stage, two orthogonally-mounted video cameras for viewing sample, fluorescence detector (Si-drift diode) and diffraction detector (a scintillation detector or a CCD). Three different levels of monochromaticity are available. Conventional monochromatic x-rays from a double-bounced Si (111) crystal monochromator (DCM, D E/E=1E-4), wide band-pass monochromatic x-rays from a double multilayer monochromator (DMM, D E/E=1~4E-2) and pink beam. The available x-ray range is from 5 keV to 30 keV. The lower limit is due to the x-ray windows and the upper limit is due to the critical angle of the x-ray mirror. Two different coatings (Cr and Pt) for the x-ray mirror allow either 20 keV or 30 keV energy cutoff.

320

The Biggest Bangs The Mystery of Gamma-Ray Bursts,  

E-Print Network (OSTI)

The Biggest Bangs The Mystery of Gamma-Ray Bursts, The Most Violent Explosions in The Universe J. I. Did a Gamma-Ray Burst Kill the Dinosaurs? Will a Burst Kill Us? #15; Glossary #15; Sources #15; Index. On January 23, 1999, one of these four cameras recorded visible light from a gamma-ray burst

Katz, Jonathan I.

Note: This page contains sample records for the topic "ray 202-586-5077 tosha" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

The Biggest Bangs The Mystery of Gamma-Ray Bursts,  

E-Print Network (OSTI)

The Biggest Bangs The Mystery of Gamma-Ray Bursts, The Most Violent Explosions in The Universe J. I a Gamma-Ray Burst Kill the Dinosaurs? Will a Burst Kill Us? · Glossary · Sources · Index viii #12;Chapter of these four cameras recorded visible light from a gamma-ray burst as it was happening, which had been the holy

Katz, Jonathan I.

322

Gamma-Ray Bursts Nuclear Test Ban Treaty, 1963  

E-Print Network (OSTI)

Lecture 18 Gamma-Ray Bursts #12;Nuclear Test Ban Treaty, 1963 First Vela satellite pair launched and their predecessors, Vela 4, discovered the first gamma-ray bursts. The discovery was announced by Klebesadel, Strong, and Olson (ApJ, 182, 85) in 1973. #12;First Gamma-Ray Burst The Vela 5 satellites functioned from July, 1969

Harrison, Thomas

323

Gamma ray bursts observed with WATCH?EURECA  

Science Journals Connector (OSTI)

The WATCH wide field x?ray monitor has the capability of independently locating bright Gamma Ray Bursts to 1 accuracy. We report the preliminary positions of 12 Gamma Ray Bursts observed with the WATCH monitor flown on the ES spacecraft EURECA during its 11 month mission. Also the recurrence of the Soft Gamma Repeater SGR 1900+14 in 1992 is verified.

S. Brandt; N. Lund; A. J. Castro?Tirado

1994-01-01T23:59:59.000Z

324

Improvement of YOHKOH Hard X-Ray Imaging  

Science Journals Connector (OSTI)

......Figure la shows the X-ray penetration rate through a single, 0.5 mm...index Fig. 1. (a) X-ray penetration rate through a single tung- sten...the K-escape. (b) X-ray penetration rates averaged over the HXT M2 and......

Jun Sato; Takeo Kosugi; Kazuo Makishima

1999-02-01T23:59:59.000Z

325

A complete sample of long bright Swift gamma ray bursts  

Science Journals Connector (OSTI)

...complete sample of long bright Swift gamma ray bursts Gianpiero Tagliaferri 1 Ruben...subsample of Swift long bright gamma ray bursts (GRBs). The sample, made...correlations and the nature of dark bursts. gamma ray bursts|complete sample|luminosity...

2013-01-01T23:59:59.000Z

326

Gamma-ray bursts spectral correlations and their cosmological use  

Science Journals Connector (OSTI)

...research-article Discussion Meeting Issue Gamma-ray bursts organized by Alan Wells, Ralph...J. Wijers and Martin Rees Gamma-ray bursts spectral correlations and their...correlations involving the long-gamma-ray bursts (GRBs) prompt emission energy...

2007-01-01T23:59:59.000Z

327

Gamma-ray bursts, QSOs and active galaxies  

Science Journals Connector (OSTI)

...research-article Discussion Meeting Issue Gamma-ray bursts organized by Alan Wells, Ralph...J. Wijers and Martin Rees Gamma-ray bursts, QSOs and active galaxies Geoffrey...of the absorption spectra of gamma-ray burst (GRB) sources or afterglows...

2007-01-01T23:59:59.000Z

328

Short gamma-ray bursts near and far  

Science Journals Connector (OSTI)

...research-article Discussion Meeting Issue Gamma-ray bursts organized by Alan Wells, Ralph...Wijers and Martin Rees Short gamma-ray bursts near and far Andrew J Levan...understanding the nature of short gamma-ray bursts (GRBs) has been rapid since...

2007-01-01T23:59:59.000Z

329

TERRESTRIAL GAMMA-RAY FLASH PRODUCTION BY LIGHTNING  

E-Print Network (OSTI)

TERRESTRIAL GAMMA-RAY FLASH PRODUCTION BY LIGHTNING A DISSERTATION SUBMITTED TO THE DEPARTMENT gamma-ray flashes (TGFs) are brief flashes of gamma-rays originating in the Earth's atmosphere) that extends from below 25 keV to above 20 MeV. When good lightning data exists, TGFs are closely associated

330

Small Angle X-ray Scattering (SAXS) Laboratory Learning Experiences  

E-Print Network (OSTI)

.A. & Svergun D.I. (1987). Structure Analysis by Small-Angle X-Ray and Neutron Scattering. NY: Plenum PressSmall Angle X-ray Scattering (SAXS) Laboratory Learning Experiences o - Use of small angle X-ray scattering instrumentation o - Programs that you will use SAXS (BRUKER AXS) PRIMUS (Konarev, Volkov, Koch

Meagher, Mary

331

X-ray Diffraction Laboratory Department of Chemistry  

E-Print Network (OSTI)

X-ray Diffraction Laboratory Department of Chemistry Texas A & M University College Station, Texas Phone : 979-845-9125 www.chem.tamu.edu/xray xray@tamu.edu X-rayDiffractionLaboratory DepartmentofChemistry 3255TAMU CollegeStation,TX77843-3255 Mission The purpose of our laboratory is to provide X-ray

Meagher, Mary

332

X-ray Diffraction Practicals 1 Graphics Programs  

E-Print Network (OSTI)

X-ray Diffraction Practicals 1 Graphics Programs that will read SHELX or CIF files J. Reibenspies, N. Bhuvanesh ver 1.0.0 #12;X-ray Diffraction Practicals 2 Free software. Gretep : Reads SHELX files shelx files or output thermal ellipsoid plots. http://www.umass.edu/microbio/rasmol/ #12;X-ray

Meagher, Mary

333

X-ray Emission from Massive Stars David Cohen  

E-Print Network (OSTI)

X-ray Emission from Massive Stars David Cohen Department of Physics and Astronomy Swarthmore University, Oct. 13, 2005 astro.swarthmore.edu/~cohen/ #12;Outline 1. What you need to know: a. X-rays from the Sun - magnetic activity, x-ray spectra b. Hot stars c. Radiation-driven winds and the Doppler shift d

Cohen, David

334

X-Ray Photoelectron Spectroscopy XPS Mark Engelhard  

E-Print Network (OSTI)

X-Ray Photoelectron Spectroscopy XPS Mark Engelhard 1 #12;EMSL XPS Instrumentation 2 Physical Electronics Quantera XPS High Energy Resolution Focused X-ray Beam Capability Catalysis reaction and processing chamber with inert atmosphere glove box connected to a PHI Quantera Scanning X-ray Microprobe

335

X-rays Illuminate Ancient Archimedes Text  

NLE Websites -- All DOE Office Websites (Extended Search)

Related Links: Related Links: May 2005 Headlines TIP Article Press Release Walters Art Museum SSRL Home Page SLAC Home Page Stanford Home Page Tuesday, 31 May 2005 X-rays Illuminate Ancient Archimedes Text (contact: Uwe Bergmann, bergmann@slac.stanford.edu) Archimedes Figure Image provided by Will Noel, The Walters Art Museum An early transcription of Archimedes' mathematical theories has been brought to light through the probing of high-intensity x-rays at SSRL's BL6-2. The text contains part of the Method of Mechanical Theorems, one of Archimedes' most important works, which was probably copied out by a scribe in the tenth century. The parchment on which it was written was later scraped down and reused as pages in a twelfth century prayer book, producing a document known as a palimpsest (which comes from the Greek,

336

HIGH BRILLIANCE X-RAY SCATTERING FOR  

NLE Websites -- All DOE Office Websites (Extended Search)

BRILLIANCE X-RAY SCATTERING FOR BRILLIANCE X-RAY SCATTERING FOR LIFE SCIENCES (LIX) Group Leader: Lin Yang Proposal Team: O. Bilsel 1 , B. Hsiao 2 , H. Huang 3 , T. Irving 4 , A. Menzel 5 , L. Pollack 6 , C. Riekel 7 , J. Rubert 8 , H. Tsuruta 9 , L. Yang 10 1 University of Massachusetts, 2 Stony Brook University, 3 Rice University, 4 IIT, 5SLS, 6 Cornell University, 7 European Synchrotron Radiation Facility, 8 NEU, 9 Stanford Synchrotron Radiation Lightsource, 10 Brookhaven National Laboratory TECHNIQUES AND CAPABILITIES APPLICATIONS ADDITIONAL INFORMATION * Energy range 2-20keV using undulator source. Simultaneous SAXS/WAXS to cover 0.003-3Å -1 at 12keV with 1 micron spot size * Time-resolved solution scattering with resolution of (1) microseconds to milliseconds using continuous-flow mixing (5µm x 10µm spot size) and (2) milliseconds using stopped-

337

Lorentz violation from gamma-ray bursts  

E-Print Network (OSTI)

The constancy of light speed is a basic assumption in Einstein's special relativity, and consequently the Lorentz invariance is a fundamental symmetry of space-time in modern physics. However, it is speculated that the speed of light becomes energy-dependent due to the Lorentz invariance violation~(LV) in various new physics theories. We analyse the data of the energetic photons from the gamma-ray bursts (GRBs) by the Fermi Gamma-Ray Space Telescope, and find more events to support the energy dependence in the light speed with both linear and quadratic form corrections. We provide two scenarios to understand all the new-released Pass~8 data of bright GRBs by the Fermi-LAT Collaboration, with predictions from such scenarios being testable by future detected GRBs.

Shu Zhang; Bo-Qiang Ma

2014-06-18T23:59:59.000Z

338

Gamma ray bursts: A 1983 overview  

Science Journals Connector (OSTI)

Gamma?ray burst observations are reviewed with mention of new gamma?ray and optical transient measurements and with discussions of the controversial contradictory and unresolved issues that have recently emerged: burst spectra appear to fluctuate in time as rapidly as they are measured implying that any one spectrum may be incorrect; energy spectra can be obligingly fitted to practically any desired shape implying in effect that no objective spectral resolution exists at all; burst fluxes and temporal quantities including the total event energy are characterized very differently with differing instruments implying that even elementary knowledge of their properties is instrumentally subjective; finally the log N?log S determinations are deficient in the weak bursts while there is no detection of a source direction anisotropy implying that Ptolemy was right or that burst source distance estimates are basically guesswork. These issues may remain unsolved until vastly improved instruments are flown.

T. L. Cline

1984-01-01T23:59:59.000Z

339

Real time gamma-ray signature identifier  

DOE Patents (OSTI)

A real time gamma-ray signature/source identification method and system using principal components analysis (PCA) for transforming and substantially reducing one or more comprehensive spectral libraries of nuclear materials types and configurations into a corresponding concise representation/signature(s) representing and indexing each individual predetermined spectrum in principal component (PC) space, wherein an unknown gamma-ray signature may be compared against the representative signature to find a match or at least characterize the unknown signature from among all the entries in the library with a single regression or simple projection into the PC space, so as to substantially reduce processing time and computing resources and enable real-time characterization and/or identification.

Rowland, Mark (Alamo, CA); Gosnell, Tom B. (Moraga, CA); Ham, Cheryl (Livermore, CA); Perkins, Dwight (Livermore, CA); Wong, James (Dublin, CA)

2012-05-15T23:59:59.000Z

340

Element 104 identified by characteristic x rays  

Science Journals Connector (OSTI)

A research team at the Oak Ridge National Laboratory has recently announced that they have conclusively identified the 257 isotope of element 104. This new work shows promise of shedding light on the controversy between Albert Ghiorso and Georgi N. Flerov the leaders respectively of the groups at Lawrence Berkeley Laboratory and the Joint Institute for Nuclear Research Dubna. The isotope 104 X 257 decays by alpha emission to 102 No 253 with a half?life of 4.3 seconds. The Oak Ridge group observed the K?series x rays from nobelium in coincidence with the alpha particles from 104 X 257 ; the observation of x?ray spectra has never been reported previously by the Berkeley or Dubna workers according to Curtis E. Bemis Jr spokesman for the group.

Ronald J. Cohn

1973-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ray 202-586-5077 tosha" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

The Pierre Auger Cosmic Ray Observatory  

E-Print Network (OSTI)

The Pierre Auger Observatory, located on a vast, high plain in western Argentina, is the world's largest cosmic ray observatory. The objectives of the Observatory are to probe the origin and characteristics of cosmic rays above $10^{17}$ eV and to study the interactions of these, the most energetic particles observed in nature. The Auger design features an array of 1660 water-Cherenkov particle detector stations spread over 3000 km$^2$ overlooked by 24 air fluorescence telescopes. In addition, three high elevation fluorescence telescopes overlook a 23.5 km$^2$, 61 detector infill array. The Observatory has been in successful operation since completion in 2008 and has recorded data from an exposure exceeding 40,000 km$^2$ sr yr. This paper describes the design and performance of the detectors, related subsystems and infrastructure that make up the Auger Observatory.

,

2015-01-01T23:59:59.000Z

342

Phenomenology of Gamma-Ray Jets  

E-Print Network (OSTI)

We discuss some phenomenological aspects of $\\gamma$-ray emitting jets. In particular, we present calculations of the $\\gamma$-sphere and $\\pi$-sphere for various target photon fields, and employ them to demonstrate how $\\gamma$-ray observations at very high energies can be used to constraint the Doppler factor of the emitting plasma and the production of VHE neutrinos. We also consider the implications of the rapid TeV variability observed in M87 and the TeV blazars, and propose a model for the very rapid TeV flares observed with HESS and MAGIC in some blazars,that accommodates the relatively small Doppler factors inferred from radio observations. Finally, we briefly discuss the prospects for detecting VHE neutrinos from relativistic jets.

Amir Levinson

2007-09-10T23:59:59.000Z

343

Neutron-driven gamma-ray laser  

DOE Patents (OSTI)

A lasing cylinder emits laser radiation at a gamma-ray wavelength of 0.87 .ANG. when subjected to an intense neutron flux of about 400 eV neutrons. A 250 .ANG. thick layer of Be is provided between two layers of 100 .ANG. thick layer of .sup.57 Co and these layers are supported on a foil substrate. The coated foil is coiled to form the lasing cylinder. Under the neutron flux .sup.57 Co becomes .sup.58 Co by neutron absorption. The .sup.58 Co then decays to .sup.57 Fe by 1.6 MeV proton emission. .sup.57 Fe then transitions by mesne decay to a population inversion for lasing action at 14.4 keV. Recoil from the proton emission separates the .sup.57 Fe from the .sup.57 Co and into the Be, where Mossbauer emission occurs at a gamma-ray wavelength.

Bowman, Charles D. (Los Alamos, NM)

1990-01-01T23:59:59.000Z

344

X-ray radiography for container inspection  

DOE Patents (OSTI)

Arrangements of X-ray inspection systems are described for inspecting high-z materials in voluminous objects such as containers. Inspection methods may involve generating a radiographic image based on detected attenuation corresponding to a pulsed beams of radiation transmitted through a voluminous object. The pulsed beams of radiation are generated by a high-energy source and transmitted substantially downward along an incident angle, of approximately 1.degree. to 30.degree., to a vertical axis extending through the voluminous object. The generated radiographic image may be analyzed to detect on localized high attenuation representative of high-z materials and to discriminate high-z materials from lower and intermediate-z materials on the basis of the high density and greater attenuation of high-z material for higher energy (3-10 MeV) X-rays, and the compact nature of threatening masses of fissionable materials.

Katz, Jonathan I. (Clayton, MO); Morris, Christopher L. (Los Alamos, NM)

2011-06-07T23:59:59.000Z

345

Gamma Ray Bursts as cosmological tools  

E-Print Network (OSTI)

The use of Gamma Ray Bursts as ``standard candles'' has been made possible by the recent discovery of a very tight correlation between their rest frame intrinsic properties. This correlation relates the GRB prompt emission peak spectral energy E_peak to the energy E_gamma corrected for the collimation angle theta_jet of these sources. The possibility to use GRBs to constrain the cosmological parameters and to study the nature of Dark Energy are very promising.

G. Ghirlanda; G. Ghisellini; L. Nava; C. Firmani

2005-12-30T23:59:59.000Z

346

Gamma Ray Bursts as Cosmological Tools  

Science Journals Connector (OSTI)

The use of Gamma Ray Bursts as standard candles has been made possible by the recent discovery of a very tight correlation between their rest frame intrinsic properties. This correlation relates the GRB prompt emission peak spectral energy E peak to the energy E ? corrected for the collimation angle ?jet of these sources. The possibility to use GRBs to constrain the cosmological parameters and to study the nature of Dark Energy are very promising.

G. Ghirlanda; G. Ghisellini; L. Nava; C. Firmani

2005-01-01T23:59:59.000Z

347

Sample holder for X-ray diffractometry  

DOE Patents (OSTI)

A sample holder for use with X-ray diffractometers with the capability to rotate the sample, as well as to adjust the position of the sample in the x, y, and z directions. Adjustment in the x direction is accomplished through loosening set screws, moving a platform, and retightening the set screws. Motion translators are used for adjustment in the y and z directions. An electric motor rotates the sample, and receives power from the diffractometer.

Hesch, Victor L. (Los Alamos, NM)

1992-01-01T23:59:59.000Z

348

Columbia University X-Ray Measurements  

E-Print Network (OSTI)

V-720 keV · NaI 2x2x2" detector views an energy range of 1 keV-3 MeV Store signal in the tree. computer configuration. Plasmas were created using multi-frequency ECRH, and we find that most of the plasma energy is stored in the fast electrons. The energy spectrum of the x-ray emission below 740 keV is measured

349

Phenomenology of cosmic ray air showers  

E-Print Network (OSTI)

The properties of cosmic rays with energies above 1PeV have to be deduced from the spacetime structure and particle content of the air showers which they initiate. In this review, a summary of the phenomenology of these giant air showers is presented. We describe the hadronic interaction models used to extrapolate results from collider data to ultra high energies, an also the main electromagnetic processes that govern the longitudinal shower evolution as well as the lateral spread of particles.

M. T. Dova

2005-05-30T23:59:59.000Z

350

Silicon Absolute X-Ray Detectors  

SciTech Connect

The responsivity of silicon photodiodes having no loss in the entrance window, measured using synchrotron radiation in the 1.75 to 60 keV range, was compared to the responsivity calculated using the silicon thickness measured using near-infrared light. The measured and calculated responsivities agree with an average difference of 1.3%. This enables their use as absolute x-ray detectors.

Seely, John F. [Naval Research Laboratory, Washington, D.C. 20375 (United States); Korde, Raj; Sprunck, Jacob [International Radiation Detectors, Inc., Torrance, CA 90505-5243 (United States); Medjoubi, Kadda; Hustache, Stephanie [Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette CEDEX (France)

2010-06-23T23:59:59.000Z

351

Ultrashort x-ray backlighters and applications  

SciTech Connect

Previously, using ultrashort laser pulses focused onto solid targets, we have experimentally studied a controllable ultrafast broadband radiation source in the extreme ultraviolet for time-resolved dynamical studies in ultrafast science [J. Workman, A. Maksimchuk, X. Llu, U. Ellenberger, J. S. Coe, C.-Y. Chien, and D. Umstadter, ``Control of Bright Picosecond X-Ray Emission from Intense Sub- Picosecond Laser-Plasma Interactions,`` Phys. Rev. Lett. 75, 2324 (1995)]. Once armed with a bright ultrafast broadband continuum x-ray source and appropriate detectors, we used the source as a backlighter to study a remotely produced plasma. The application of the source to a problem relevant to high-density matter completes the triad: creating and controlling, efficiently detecting, and applying the source. This work represented the first use of an ultrafast laser- produced x-ray source as a time-resolving probe in an application relevant to atomic, plasma and high-energy-density matter physics. Using the x-ray source as a backlighter, we adopted a pump-probe geometry to investigate the dynamic changes in electronic structure of a thin metallic film as it is perturbed by an ultrashort laser pulse. Because the laser deposits its energy in a skin depth of about 100 {Angstrom} before expansion occurs, up to gigabar pressure shock waves lasting picosecond in duration have been predicted to form in these novel plasmas. This raises the possibility of studying high- energy-density matter relevant to inertial confinement fusion (ICF) and astrophysics in small-scale laboratory experiments. In the past, time-resolved measurements of K-edge shifts in plasmas driven by nanosecond pulses have been used to infer conditions in highly compressed materials. In this study, we used 100-fs laser pulses to impulsively drive shocks into a sample (an untamped 1000 {Angstrom} aluminum film on 2000 {Angstrom} of parylene-n), measuring L-edge shifts.

Umstadter, D., University of Michigan

1997-08-01T23:59:59.000Z

352

TENDER ENERGY X-RAY ABSORPTION  

NLE Websites -- All DOE Office Websites (Extended Search)

TENDER ENERGY X-RAY ABSORPTION TENDER ENERGY X-RAY ABSORPTION SPECTROSCOPY (TES) Project Team: S. Bare 1,2 , J. Brandes 3 , T. Buonassisi 4 , J. Chen 5,2 , M. Croft 6 , E. DiMasi 7 , A. Frenkel 8,2 , D. Hesterberg 9 , S. Hulbert 7,2 , S. Khalid 7 , S. Myneni 10 , P. Northrup 7,11 , E.T. Rasbury 11 , B. Ravel 12 , R. Reeder 11 , J. Rodriguez 7,2 , D. Sparks 5,13 , V. Stojanoff 7 , G. Waychunas 14 1 UOP LLC, 2 Synchrotron Catalysis Consortium, 3 Skidaway Inst. of Oceanography, 4 MIT Laboratory for Photovoltaics Research, 5 Univ. of Delaware, 6 Rutgers Univ., 7 Brookhaven National Lab, 8 Yeshiva Univ., 9 North Carolina State Univ., 10 Princeton Univ., 11 Stony Brook Univ., 12 NIST, 13 Delaware Environmental Inst., 14 Lawrence Berkeley National Lab TECHNIQUES: High performance and in-situ X-ray absorption spectroscopy and spatially-resolved XAS of

353

The Galactic gamma-ray club  

E-Print Network (OSTI)

The exclusive Galactic gamma-ray club has opened up to new members. Supernova remnants, pulsar wind nebulae, and massive binary systems hosting a compact object have recently joined the young pulsars as firmly established sources of gamma rays in the Milky Way. Massive young stellar clusters are on the waiting list to join the club. Only the fine imaging recently obtained at TeV energies could resolve specific sources. The samples are sparse, but raise exciting questions. The jet or pulsar-wind origin of the emission in binaries has been hotly debated, but it seems that both types of systems have been recently detected. The nature of the radiation in shock accelerators is still questioned: do nuclei contribute a lot, a little, or not to the gamma rays and what energy do they carry away from the shock budget? The acceleration process and the structural evolution of the pulsar winds are still uncertain. The magnetic field distribution in all these systems is a key, but poorly constrained, ingredient to model the multi-wavelength data, particle transport and electron ageing. It must, however, be determined in order to efficiently probe particle distributions and the acceleration mechanisms. The source samples soon to be expected from GLAST and the Cherenkov telescopes should bring new valuable test cases and they will, for the first time, shed statistical light on the collective behaviour of these different types of accelerators.

Isabelle A. Grenier

2008-04-02T23:59:59.000Z

354

Remnants from Gamma-Ray Bursts  

Science Journals Connector (OSTI)

We model the intermediate-time evolution of a "jetted" gamma-ray burst (GRB) as two blobs of matter colliding with the interstellar medium. We follow the hydrodynamic evolution of this system numerically and calculate the bremsstrahlung and synchrotron images of the remnant. We find that for a burst energy of 1051 ergs the remnant becomes spherical after ~5000 yr, when it has collected ~50 M? of interstellar mass. This result is independent of the exact details of the GRB, such as the opening angle. After this time a gamma-ray burst remnant has an expanding sphere morphology. The similarity to a supernova remnant makes it difficult to distinguish between the two at this stage. The expected number of nonspherical gamma-ray burst remnants is ~0.05 per galaxy for a beaming factor of 0.01 and a burst energy of 1051 ergs. Our results suggest that the double-shell object DEM L316 is not a GRB remnant.

Shai Ayal; Tsvi Piran

2001-01-01T23:59:59.000Z

355

Properties of prompt-fission ? rays  

Science Journals Connector (OSTI)

In a Monte Carlo Hauser-Feshbach statistical framework, we describe spectra, average multiplicities, average energy, and multiplicity distributions of the prompt ? rays produced in the thermal neutron-induced fission of U235 and Pu239, and the spontaneous fission of Cf252. Comparisons against recent experimental data show reasonable agreement in all cases investigated, after adjustment of the initial spin distribution in the fission fragments. In particular, when we include in the calculation the Doppler broadening we obtain a qualitatively good description of the measured low-energy spectra, where contributions from collective discrete transitions in specific fragments can be identified. At higher energies, both the calculated neutron and ?-ray spectra are softer than experimental data. The impact of selected model parameters on the prompt neutron and ?-ray spectra is analyzed. Finally, we present the prompt ? spectrum and multiplicity distribution for the neutron-induced fission of U235 for 5.5 MeV neutron incident energy, just below the threshold for second-chance fission.

I. Stetcu; P. Talou; T. Kawano; M. Jandel

2014-08-26T23:59:59.000Z

356

Solution To The Gamma Ray Burst Mystery?  

E-Print Network (OSTI)

Photoexcitation and ionization of partially ionized heavy atoms in highly relativistic flows by interstellar photons, followed by their reemission in radiative recombination and decay, boost star-light into beamed $\\gamma$ rays along the flow direction. Repeated excitation/decay of highly relativistic baryonic ejecta from merger or accretion induced collapse of neutron stars in dense stellar regions (DSRs), like galactic cores, globular clusters and super star-clusters, can convert enough kinetic energy in such events in distant galaxies into cosmological gamma ray bursts (GRBs). The model predicts remarkably well all the main observed temporal and spectral properties of GRBs. Its success strongly suggests that GRBs are $\\gamma$ ray tomography pictures of DSRs in galaxies at cosmological distances with unprecedented resolution: A time resolution of $dt\\sim 1~ms$ in a GRB can resolve stars at a Hubble distance which are separated by only $D\\sim 10^{10}cm$. This is equivalent to the resolving power of an optical telescope with a diameter larger than one Astronomical Unit!

Nir J. Shaviv; Arnon Dar

1996-08-21T23:59:59.000Z

357

Solar panels as cosmic-ray detectors  

E-Print Network (OSTI)

Due to fundamental limitations of accelerators, only cosmic rays can give access to centre-of- mass energies more than one order of magnitude above those reached at the LHC. In fact, extreme energy cosmic rays (1018 eV - 1020 eV) are the only possibility to explore the 100 TeV energy scale in the years to come. This leap by one order of magnitude gives a unique way to open new horizons: new families of particles, new physics scales, in-depth investigations of the Lorentz symmetries. However, the flux of cosmic rays decreases rapidly, being less than one particle per square kilometer per year above 1019 eV: one needs to sample large surfaces. A way to develop large-effective area, low cost, detectors, is to build a solar panel-based device which can be used in parallel for power generation and Cherenkov light detection. Using solar panels for Cherenkov light detection would combine power generation and a non-standard detection device.

Stella, Carlo; Assis, Pedro; Brogueira, Pedro; Santo, Catarina Espirito; Goncalves, Patricia; Pimenta, Mario; De Angelis, Alessandro

2014-01-01T23:59:59.000Z

358

The X-ray Telescope of CAST  

E-Print Network (OSTI)

The Cern Axion Solar Telescope (CAST) is in operation and taking data since 2003. The main objective of the CAST experiment is to search for a hypothetical pseudoscalar boson, the axion, which might be produced in the core of the sun. The basic physics process CAST is based on is the time inverted Primakoff effect, by which an axion can be converted into a detectable photon in an external electromagnetic field. The resulting X-ray photons are expected to be thermally distributed between 1 and 7 keV. The most sensitive detector system of CAST is a pn-CCD detector combined with a Wolter I type X-ray mirror system. With the X-ray telescope of CAST a background reduction of more than 2 orders off magnitude is achieved, such that for the first time the axion photon coupling constant g_agg can be probed beyond the best astrophysical constraints g_agg < 1 x 10^-10 GeV^-1.

M. Kuster; H. Bruninger; S. Cbrian; M. Davenport; C. Elefteriadis; J. Englhauser; H. Fischer; J. Franz; P. Friedrich; R. Hartmann; F. H. Heinsius; D. H. H. Hoffmann; G. Hoffmeister; J. N. Joux; D. Kang; K. Knigsmann; R. Kotthaus; T. Papaevangelou; C. Lasseur; A. Lippitsch; G. Lutz; J. Morales; A. Rodrguez; L. Strder; J. Vogel; K. Zioutas

2007-05-10T23:59:59.000Z

359

The radiation-tolerant x-ray monitor  

SciTech Connect

A vacuum photoelectric detector (monitor) (VPD) designed for plasma tomography, megnetohydrodynamics monitoring, and imaging with the help of thermal x-ray radiation on the ITER facility is described. Laboratory experiments demonstrate that VPD has high sensitivity to thermal x rays and low sensitivity to hard gamma rays and neutrons. The results of tests of a prototype of this monitor on a {sup 60}Co source of gamma rays, on nuclear reactor and its calibration using radiation from an x-ray tube, and tests of its serviceability on the T-10 facility are presented.

Gott, Yu. V.; Stepanenko, M. M. [Nuclear Fusion Institute, Russian Research Center 'Kurchatov Institute', Kurchatov Sq. 1, Moscow 123182 (Russian Federation)

2008-10-15T23:59:59.000Z

360

Calibrating X-ray Imaging Devices for Accurate Intensity Measurement  

SciTech Connect

The purpose of the project presented is to develop methods to accurately calibrate X-ray imaging devices. The approach was to develop X-ray source systems suitable for this endeavor and to develop methods to calibrate solid state detectors to measure source intensity. NSTec X-ray sources used for the absolute calibration of cameras are described, as well as the method of calibrating the source by calibrating the detectors. The work resulted in calibration measurements for several types of X-ray cameras. X-ray camera calibration measured efficiency and efficiency variation over the CCD. Camera types calibrated include: CCD, CID, back thinned (back illuminated), front illuminated.

Haugh, M. J.

2011-07-28T23:59:59.000Z

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361

Compton Recoil Electron Tracking With the TIGRE Gamma-Ray Balloon Experiment  

E-Print Network (OSTI)

AGNs), pulsars, gamma-ray bursts, cosmic ray interactionssensitive to cosmic gamma-ray bursts in the energy range ofGalactic center, a single gamma-ray burst which occurred 10

Kamiya, Kaoru

2011-01-01T23:59:59.000Z

362

E-Print Network 3.0 - airborne lead x-ray Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

Pulsars... you'd . . . Active Galactic . . . X-ray binaries Pulsars and relatives Gamma-ray bursts Gravitational... 1 - Type 2 X-ray binaries - Low mass X-ray binaries (LMXBs)...

363

E-Print Network 3.0 - attosecond kev x-ray Sample Search Results  

NLE Websites -- All DOE Office Websites (Extended Search)

de Montral Collection: Engineering 3 Generation of Attosecond X-ray and gamma-ray via Compton backscattering Summary: Generation of Attosecond X-ray and gamma-ray via...

364

Collection: High-Energy Cosmic Ray Event Data from the Pierre...  

Office of Scientific and Technical Information (OSTI)

High-Energy Cosmic Ray Event Data from the Pierre Auger Cosmic Ray Observatory Citation Details Title: High-Energy Cosmic Ray Event Data from the Pierre Auger Cosmic Ray...

365

Quantitative x-ray imager (abstract)  

SciTech Connect

We report on development of a quantitative x-ray imager (QXI) for the national Inertial Confinement Fusion Program. Included in this development is a study of photocathode response as a function of photon energy, 2--17.5 keV, which is related to diagnostic development on the National Ignition Facility (NIF). The QXI is defined as being a quantative imager due to the repeated characterization. This instrument is systematically checked out, electronically as well as its photocathode x-ray response, both on a direct current and pulsed x-ray sources, before and after its use on a shot campaign. The QXI is a gated x-ray imager1 used for a variety of experiments conducted in the Inertial Confinement Fusion and Radiation Physics Program. The camera was assembled in Los Alamos and has been under development since 1997 and has now become the workhorse framing camera by the program. The electronics were built by Grant Applied Physics of San Fransisco, CA.2 The QXI has been used at the LANL Trident, LLNL Nova, and University of Rochester Laboratory OMEGA laser facilities. The camera consists of a grated microchannel plate (MCP), a phosphor coated fiberoptic faceplate coupled to film for data readout, along with high speed electronic pulsers to drive the x-ray detector. The QXI has both a two-strip and a four-strip detection head and has the ability to individually bias the gain of each of the strips. The timing of the QXI was done at the Trident short pulse laboratory, using 211 nm light. Single strip jitter was looked at as well and determined to be <25 ps. Flatfielding of the photocathode across the MCP was done with the Trident main laser with 150 J on a gold disk with a 1 ns. Spatial resolution was determined to be <5 {mu}m by using the same laser conditions as before and a backlit 1000 lp/in. grid. The QXI has been used on cylindrical implosion work at the Nova Laser Facility, and on direct-drive cylinder mix and indirect-drive high convergence implosion experiments at OMEGA. Its two-strip module has provided the capability to look at point backlighters, as part of technique development for experiments on the NIF. Its next use will be in March 2000 with its off axis viewer nose at Omega, providing a perpendicular view of Rayleigh--Taylor spike dissipation.

Evans, Scott C.; Archuleta, Tom N.; Oertel, John A.; Walsh, Peter J.

2001-01-01T23:59:59.000Z

366

X-ray Studies of Unidentified Galactic TeV Gamma-ray Sources  

SciTech Connect

Many of the recently discovered Galactic TeV sources remain unidentified to date. A large fraction of the sources is possibly associated with relic pulsar wind nebula (PWN) systems. One key question here is the maximum energy (beyond TeV) attained in the compact PWNe. Hard X-ray emission can trace those particles, but current non-focussing X-ray instruments above 10 keV have difficulties to deconvolve the hard pulsar spectrum from its surrounding nebula.Some of the new TeV sources are also expected to originate from middle-aged and possibly even from old supernova remnants (SNR). But no compelling case for such an identification has been found yet. In established young TeV-emitting SNRs, X-ray imaging above 10 keV could help to disentangle the leptonic from the hadronic emission component in the TeV shells, if secondary electrons produced in hadronic collisions can be effectively detected. As SNRs get older, the high energy electron component is expected to fade away. This may allow to verify the picture through X-ray spectral evolution of the source population.Starting from the lessons we have learned so far from X-ray follow-up observations of unidentified TeV sources, prospects for Simbol-X to resolve open questions in this field will be discussed.

Puehlhofer, Gerd [Institut fuer Astronomie und Astrophysik, Sand 1, 72076 Tuebingen (Germany)

2009-05-11T23:59:59.000Z

367

EVIDENCE OF CONTRIBUTION OF INTERVENING CLOUDS TO GAMMA-RAY BURST'S X-RAY COLUMN DENSITY  

SciTech Connect

The origin of excess of X-ray column density with respect to optical extinction in gamma-ray bursts (GRBs) is still a puzzle. A proposed explanation of the excess is the photoelectric absorption due to the intervening clouds along a GRB's line of sight. Here, we test this scenario by using the intervening Mg II absorption as a tracer of the neutral hydrogen column density of the intervening clouds. We identify a connection between the large X-ray column density (and large column density ratio of log (N{sub H,X}/N{sub H{sub I}})?0.5) and large neutral hydrogen column density probed by the Mg II doublet ratio (DR). In addition, GRBs with large X-ray column density (and large ratio of log (N{sub H,X}/N{sub H{sub I}})>0) tend to have multiple saturated intervening absorbers with DR < 1.2. These results therefore indicate an additional contribution from the intervening system to the observed X-ray column density in some GRBs, although the contribution from the host galaxy alone cannot be excluded based on this study.

Wang, J., E-mail: wj@bao.ac.cn [National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)

2013-10-20T23:59:59.000Z

368

X-Ray Interactions with Matter from the Center for X-Ray Optics (CXRO)  

DOE Data Explorer (OSTI)

The primary interactions of low-energy x-rays within condensed matter, viz. photoabsorption and coherent scattering, are described for photon energies outside the absorption threshold regions by using atomic scattering factors. The atomic scattering factors may be accurately determined from the atomic photoabsorption cross sections using modified Kramers-Kronig dispersion relations. From a synthesis of the currently available experimental data and recent theoretical calculations for photoabsorption, the angle-independent, forward-scattering components of the atomic scattering factors have been thus semiempirically determined and tabulated here for 92 elements and for the region 50-30,000 eV. Atomic scattering factors for all angles of coherent scattering and at the higher photon energies are obtained from these tabulated forward-scattering values by adding a simple angle-dependent form-factor correction. The incoherent scattering contributions that become significant for the light elements at the higher photon energies are similarly determined. The basic x-ray interaction relations that are used in applied x-ray physics are presented here in terms of the atomic scattering factors. The bulk optical constants are also related to the atomic scattering factors. These atomic and optical relations are applied to the detailed calculation of the reflectivity characteristics of a series of practical x-ray mirror, multilayer, and crystal monochromators. Comparisons of the results of this semiempirical,"atom-like", description of x-ray interactions for the low-energy region with those of experiment and ab initio theory are presented.

Henke, B.L.; Gullikson, E.M.; Davis, J.C.

369

TeV Burst of Gamma-Ray Bursts and Ultra High Energy Cosmic Rays  

E-Print Network (OSTI)

Some recent experiments detecting very high energy (VHE) gamma-rays above 10-20 TeV independently reported VHE bursts for some of bright gamma-ray bursts (GRBs). If these signals are truly from GRBs, these GRBs must emit a much larger amount of energy as VHE gamma-rays than in the ordinary photon energy range of GRBs (keV-MeV). We show that such extreme phenomena can be reasonably explained by synchrotron radiation of protons accelerated to \\sim 10^{20-21} eV, which has been predicted by Totani (1998a). Protons seem to carry about (m_p/m_e) times larger energy than electrons, and hence the total energy liberated by one GRB becomes as large as \\sim 10^{56} (\\Delta \\Omega / 4 \\pi) ergs. Therefore a strong beaming of GRB emission is highly likely. Extension of the VHE spectrum beyond 20 TeV gives a nearly model-independent lower limit of the Lorentz factor of GRBs, as $\\gamma \\gtilde 500$. Furthermore, our model gives the correct energy range and time variability of ordinary keV-MeV gamma-rays of GRBs by synchrotron radiation of electrons. Therefore the VHE bursts of GRBs strongly support the hypothesis that ultra high energy cosmic rays observed on the Earth are produced by GRBs.

Tomonori Totani

1998-10-14T23:59:59.000Z

370

Generation of first hard X-ray pulse at Tsinghua Thomson Scattering X-ray Source  

SciTech Connect

Tsinghua Thomson Scattering X-ray Source (TTX) is the first-of-its-kind dedicated hard X-ray source in China based on the Thomson scattering between a terawatt ultrashort laser and relativistic electron beams. In this paper, we report the experimental generation and characterization of the first hard X-ray pulses (51.7 keV) via head-on collision of an 800 nm laser and 46.7 MeV electron beams. The measured yield is 1.0 Multiplication-Sign 10{sup 6} per pulse with an electron bunch charge of 200 pC and laser pulse energy of 300 mJ. The angular intensity distribution and energy spectra of the X-ray pulse are measured with an electron-multiplying charge-coupled device using a CsI scintillator and silicon attenuators. These measurements agree well with theoretical and simulation predictions. An imaging test using the X-ray pulse at the TTX is also presented.

Du Yingchao; Yan Lixin; Hua Jianfei; Du Qiang; Zhang Zhen; Li Renkai; Qian Houjun; Huang Wenhui; Chen Huaibi; Tang Chuanxiang [Accelerator Laboratory, Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Key Laboratory of Particle and Radiation Imaging, Tsinghua University, Ministry of Education, Beijing 100084 (China); Key Laboratory of High Energy Radiation Imaging Fundamental Science for National Defense, Tsinghua University, Beijing 100084 (China)

2013-05-15T23:59:59.000Z

371

Apparatus for monitoring X-ray beam alignment  

DOE Patents (OSTI)

A self-contained, hand-held apparatus is provided for minitoring alignment of an X-ray beam in an instrument employing an X-ray source. The apparatus includes a transducer assembly containing a photoresistor for providing a range of electrical signals responsive to a range of X-ray beam intensities from the X-ray beam being aligned. A circuit, powered by a 7.5 VDC power supply and containing an audio frequency pulse generator whose frequency varies with the resistance of the photoresistor, is provided for generating a range of audible sounds. A portion of the audible range corresponds to low X-ray beam intensity. Another portion of the audible range corresponds to high X-ray beam intensity. The transducer assembly may include an a photoresistor, a thin layer of X-ray fluorescent material, and a filter layer transparent to X-rays but opaque to visible light. X-rays from the beam undergoing alignment penetrate the filter layer and excite the layer of fluorescent material. The light emitted from the fluorescent material alters the resistance of the photoresistor which is in the electrical circuit including the audio pulse generator and a speaker. In employing the apparatus, the X-ray beam is aligned to a complete alignment by adjusting the X-ray beam to produce an audible sound of the maximum frequency.

Steinmeyer, Peter A. (Arvada, CO)

1991-10-08T23:59:59.000Z

372

Photon Sciences | Beamlines | HXN: Hard X-ray Nanoprobe  

NLE Websites -- All DOE Office Websites (Extended Search)

HXN: Hard X-ray Nanoprobe HXN: Hard X-ray Nanoprobe Poster | Fact Sheet | Preliminary Design Report Scientific Scope The Hard X-ray Nanoprobe beamline and endstation instruments (HXN) will be designed and constructed to explore new frontiers of hard x-ray microscopy applications with the highest achievable spatial resolution. Currently the available spatial resolution for scientific applications, provided by scanning x-ray microscopes in the hard x-ray regime, is limited to ~50nm, which is still insufficient for probing the nanoscale interfacial structures critical in determining properties and functionalities of material and biological systems. The HXN beamline aims to enable x-ray experiments at spatial resolutions ranging from 10 to 30 nm with an ultimate goal of ~1 nm. Beamline Description

373

Introduction to Neutron and X-Ray Scattering  

NLE Websites -- All DOE Office Websites (Extended Search)

Scattering Studies of Thin Scattering Studies of Thin Polymer Films Introduction to Neutron and X-Ray Scattering Sunil K. Sinha UCSD/LANL Acknowledgements: Prof. R.Pynn( Indiana U.) Prof. M.Tolan (U. Dortmund) Wilhelm Conrad Röntgen 1845-1923 1895: Discovery of X-Rays 1901 W. C. Röntgen in Physics for the discovery of x-rays. 1914 M. von Laue in Physics for x-ray diffraction from crystals. 1915 W. H. Bragg and W. L. Bragg in Physics for crystal structure determination. 1917 C. G. Barkla in Physics for characteristic radiation of elements. 1924 K. M. G. Siegbahn in Physics for x-ray spectroscopy. 1927 A. H. Compton in Physics for scattering of x-rays by electrons. 1936 P. Debye in Chemistry for diffraction of x-rays and electrons in gases.

374

GAMQUEST, a Computer Program to Identify Gamma Rays  

NLE Websites -- All DOE Office Websites (Extended Search)

GAMQUEST GAMQUEST A Computer Program to Identify Gamma Rays Edgardo Browne, Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 EBROWNE@LBL.Gov Table of Contents Introduction. Program Access and Output Files. How to Run GAMQUEST. From Individual Accounts. From Guest Account. Gamma-Ray Data. GAMQUEST, a Tool for Applied Research. Searching Strategies. Examples. Neutron Activation Analysis. Gamma-Ray Spectrum Between 100 and 800 keV. Gamma-Ray Spectrum Between 800 and 1600 keV. A List of X Rays and Gamma Rays from the Decay of 192Ir (74 hr). Run GAMQUEST from Guest Account Acknowledgments. References. 1. Introduction. The characteristic energies and intensities of gamma rays emitted by radioactive isotopes are commonly used as fingerprints for isotope

375

Development of procedures for refurbishing x-ray optics at the Advanced Light Source  

E-Print Network (OSTI)

Development of procedures for refurbishing x-ray optics atpractical and robust procedures for refurbishing x-ray

Yashchuk, Valeriy V.

2013-01-01T23:59:59.000Z

376

EARLY THERMAL X-RAY EMISSION FROM LONG GAMMA-RAY BURSTS AND THEIR CIRCUMSTELLAR ENVIRONMENTS  

SciTech Connect

We performed a series of hydrodynamical calculations of an ultrarelativistic jet propagating through a massive star and the circumstellar matter (CSM) to investigate the interaction between the ejecta and the CSM. We succeed in distinguishing two qualitatively different cases in which the ejecta are shocked and adiabatically cool. To examine whether the cocoon expanding at subrelativistic speeds emits any observable signal, we calculate the expected photospheric emission from the cocoon. It is found that the emission can explain early thermal X-ray emission recently found in some long gamma-ray bursts (GRBs). The result implies that the difference of the circumstellar environment of long GRBs can be probed by observing their early thermal X-ray emission.

Suzuki, Akihiro [Center for Computational Astrophysics, National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan); Shigeyama, Toshikazu [Research Center for the Early Universe, School of Science, University of Tokyo, Bunkyo-ku, Tokyo 113-0033 (Japan)

2013-02-10T23:59:59.000Z

377

Gamma Ray Bursts: recent results and connections to very high energy Cosmic Rays and Neutrinos  

E-Print Network (OSTI)

Gamma-ray bursts are the most concentrated explosions in the Universe. They have been detected electromagnetically at energies up to tens of GeV, and it is suspected that they could be active at least up to TeV energies. It is also speculated that they could emit cosmic rays and neutrinos at energies reaching up to the $10^{18}-10^{20}$ eV range. Here we review the recent developments in the photon phenomenology in the light of \\swift and \\fermi satellite observations, as well as recent IceCube upper limits on their neutrino luminosity. We discuss some of the theoretical models developed to explain these observations and their possible contribution to a very high energy cosmic ray and neutrino background.

Pter Mszros; Katsuaki Asano; Pter Veres

2012-09-11T23:59:59.000Z

378

X-Ray Imaging Crystal Spectrometer for Extended X-Ray Sources  

SciTech Connect

Spherically or toroidally curved, double focusing crystals are used in a spectrometer for X-ray diagnostics of an extended X-ray source such as a hot plasma produced in a tokamak fusion experiment to provide spatially and temporally resolved data on plasma parameters such as ion temperature, toroidal and poloidal rotation, electron temperature, impurity ion charge-state distributions, and impurity transport. The imaging properties of these spherically or toroidally curved crystals provide both spectrally and spatially resolved X-ray data from the plasma using only one small spherically or toroidally curved crystal, thus eliminating the requirement for a large array of crystal spectrometers and the need to cross-calibrate the various crystals.

Bitter, Manfred L.; Fraekel, Benjamin; Gorman, James L.; Hill, Kenneth W.; Roquemore, Lane A.; Stodiek, Wolfgang; Goeler, Schweickhard von

1999-05-01T23:59:59.000Z

379

X-Ray Source Based on the Parametric X-Rays  

E-Print Network (OSTI)

Prospects of parametric x-rays (PXR) application for the development of a tuneable quasi-monochromatic x-ray source for medical imaging are discussed. Analysis of basic requirements for electron accelerator shows that it must be relatively low-energy and high-current linac. In comparison with known ultra-relativistic cases, at low energies PXR properties will be modified to a great extent by multiple scattering of the electrons. PXR intensity dependence on target thickness and beam energy are calculated taking multiple scattering into account. It is concluded that PXR source based on real medical accelerators is feasible and can provide x-ray flux needful for obtaining high quality medical images.

Alexander Lobko; Olga Lugovskaya

2005-09-02T23:59:59.000Z

380

MilagroA TeV Observatory for Gamma Ray Bursts  

E-Print Network (OSTI)

Milagro­A TeV Observatory for Gamma Ray Bursts B.L. Dingus and the Milagro Collaboration Los energy gamma-rays from gamma-ray bursts. The highest energy gamma rays supply very strong constraints on the nature of gamma-ray burst sources as well as fundamental physics. Because the highest energy gamma-rays

California at Santa Cruz, University of

Note: This page contains sample records for the topic "ray 202-586-5077 tosha" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Formation of Hydrogen Peroxide in Water Irradiated with X- and Alpha-Rays  

Science Journals Connector (OSTI)

... of very different ionic density, namely, 09 A. X-rays and polonium or radon?-rays. Methods. The irradiation with X-rays and the titration of hydrogen peroxide ... x-rays. The ionic yield, in the case of X-rays, suggests that the radon (3-rays probably account for less than 5 per cent of the total effect ...

P. BONET-MAURY; M. LEFORT

1948-09-04T23:59:59.000Z

382

Total Absorption Gamma-ray Spectrometer (TAGS) Intensity Distributions from INL's Gamma-Ray Spectrometry Center  

DOE Data Explorer (OSTI)

A 252Cf fission-product source and the INL on-line isotope separator were used to supply isotope-separated fission-product nuclides to a total absorption -ray spectrometer. This spectrometer consisted of a large (25.4-cm diameter x 30.5-cm long) NaI(Tl) detector with a 20.3-cm deep axial well in which is placed a 300-mm2 x 1.0-mm Si detector. The spectra from the NaI(Tl) detector are collected both in the singles mode and in coincidence with the B-events detected in the Si detector. Ideally, this detector would sum all the energy of the B- rays in each cascade following the population of daughter level by B- decay, so that the event could be directly associated with a particular daughter level. However, there are losses of energy from attenuation of the rays before they reach the detector, transmission of rays through the detector, escape of secondary photons from Compton scattering, escape of rays through the detector well, internal conversion, etc., and the measured spectra are thus more complicated than the ideal case and the analysis is more complex. Analysis methods have been developed to simulate all of these processes and thus provide a direct measure of the B- intensity distribution as a function of the excitation energy in the daughter nucleus. These data yield more accurate information on the B- distribution than conventional decay-scheme studies for complex decay schemes with large decay energies, because in the latter there are generally many unobserved and observed but unplaced rays. The TAGS data have been analyzed and published [R. E. Greenwood et al., Nucl Instr. and metho. A390(1997)] for 40 fission product-nuclides to determine the B- intensity distributions. [Copied from the TAGS page at http://www.inl.gov/gammaray/spectrometry/tags.shtml]. Those values are listed on this page for quick reference.

Greenwood, R.E.

383

Hard X-ray tails and cyclotron features in X-ray pulsars  

E-Print Network (OSTI)

We review the physical processes occurring in the magnetosphere of accreting X-ray pulsars, with emphasis on those processes that give rise to observable effects in their high (E>10 keV) energy spectra. In the second part we compare the empirical spectral laws used to fit the observed spectra with theoretical models, at the light of the BeppoSAX results on the broad-band characterization of the X-ray pulsar continuum, and the discovery of new (multiple) cyclotron resonance features.

Mauro Orlandini; Daniele Dal Fiume

2001-07-27T23:59:59.000Z

384

Acceleration of particles in Gamma Ray sources: Blazars and Gamma Ray Bursts  

Science Journals Connector (OSTI)

The objectives of my talk are to indicate the requirements for particle acceleration for both electrodynamic models and hadronic models in blazars then to propose a relativistic Fermi acceleration process to achieve the goal of UHE Cosmic Ray production in relativistic flows. Relativistic magnetic fronts when they cross each other produce an efficient Fermi process. It is also indicate how forward and backward fronts can be generated. Most of the involved physics also apply to Gamma Ray Bursts provided that they are produced by a magnetically collimated relativistic flow.

Guy Pelletier

2001-01-01T23:59:59.000Z

385

High resolution x-ray and gamma ray imaging using diffraction lenses with mechanically bent crystals  

DOE Patents (OSTI)

A method for high spatial resolution imaging of a plurality of sources of x-ray and gamma-ray radiation is provided. High quality mechanically bent diffracting crystals of 0.1 mm radial width are used for focusing the radiation and directing the radiation to an array of detectors which is used for analyzing their addition to collect data as to the location of the source of radiation. A computer is used for converting the data to an image. The invention also provides for the use of a multi-component high resolution detector array and for narrow source and detector apertures.

Smither, Robert K. (Hinsdale, IL)

2008-12-23T23:59:59.000Z

386

Space-Based Cosmic-Ray and Gamma-Ray Detectors: a Review  

E-Print Network (OSTI)

Prepared for the 2014 ISAPP summer school, this review is focused on space-borne and balloon-borne cosmic-ray and gamma-ray detectors. It is meant to introduce the fundamental concepts necessary to understand the instrument performance metrics, how they tie to the design choices and how they can be effectively used in sensitivity studies. While the write-up does not aim at being complete or exhaustive, it is largely self-contained in that related topics such as the basic physical processes governing the interaction of radiation with matter and the near-Earth environment are briefly reviewed.

Baldini, Luca

2014-01-01T23:59:59.000Z

387

Cosmic Rays on the Pacific Ocean  

Science Journals Connector (OSTI)

Records of cosmic-ray intensity obtained on the R. M. S. Aorangi during 12 voyages between Vancouver, Canada and Sydney, Australia, from March 17, 1936, to January 18, 1937, using a Carnegie model C cosmic-ray meter, are described and discussed. Typical records exhibiting the latitude effect are shown. A summary of the data taken at sea is given in the form of graphs, in which each datum point represents the average of 6 hours readings with a probable statistical error of 0.13 percent. Any variations due to a possible temperature coefficient of the instrument are negligible. The observed minimum of cosmic-ray intensity near the equator averages 10.3 percent less than the intensity at Vancouver, in satisfactory agreement, considering the difference in expermental conditions, with earlier measurements. The critical latitudes above which changes in intensity are less rapid, are found to be somewhat lower, 38.4N and 34.2S, than previously reported, and beyond these latitudes the intensity is found to continue to increase with latitude. At the higher latitudes is observed a variation, which appears to be seasonal, with the maximum in the cold months in both hemispheres. This variation is closely correlated with the atmospheric temperature. It is hence ascribed to changes in some atmospheric barrier of unknown nature, such as perhaps an atmospheric potential gradient, of whose strength the temperature of the atmosphere is an approximate but not exact index. Changes in this atmospheric barrier have been approximately allowed for by determining the external temperature coefficient and correcting the observations accordingly (this external temperature coefficient is comparable with that reported by Hess and his collaborators). The latitude effect curves as thus corrected should show the effect of the earth's magnetic field alone. They are now nearly flat beyond the critical latitudes and show a magnetic latitude effect of about 7.2 percent. This implies that a latitude effect of about 3.1 percent owes its origin to the atmospheric barrier. Seasonal variations in the corrected latitude effect curve are almost eliminated. Geomagnetic analysis of the energy distribution of the rays indicates a prominent component with a sharp energy threshold of about 7.5109 ev, and a component so weak as to be questionable, whose energy threshold is not greater than 2.5109 ev. It is not found possible to explain the 7.5109 ev threshold in terms of atmospheric absorption as has previously been supposed. Two alternative interpretations are suggested. The difference in cosmic-ray intensity between the northern and southern hemispheres under comparable conditions, as calculated from these data in various ways, appears to be no larger than the probable error of about 0.1 percent. This result is in conflict with the prediction by Compton and Getting of an excess in the north of about 0.5 percent, due to the motion of the earth with the rotation of the galaxy, but is not inconsistent with the small diurnal variation that has been found to follow sidereal time, if it is supposed that the cosmic rays acquire a part of the galactic motion.

A. H. Compton and R. N. Turner

1937-10-15T23:59:59.000Z

388

The constellation X-ray mission  

Science Journals Connector (OSTI)

The Constellation-X mission is a large collecting area X-ray facility emphasizing observations at high spectral resolution (E/?E?3003000) while covering a broad energy band (0.2540 keV). This mission will achieve a factor of 100 increased sensitivity over current capabilities and is optimized to observe the effects of extreme gravity close to black holes and test models for the formation of large scale structure in the Universe. It is apart of NASAs strategic plan for launch towards the end of the first decade of the 21st century.

N. E. White; H. Tananbaum

2001-01-01T23:59:59.000Z

389

Can Naked Singularities Yield Gamma Ray Bursts?  

E-Print Network (OSTI)

Gamma-ray bursts are believed to be the most luminous objects in the Universe. There has been some suggestion that these arise from quantum processes around naked singularities. The main problem with this suggestion is that all known examples of naked singularities are massless and hence there is effectively no source of energy. It is argued that a globally naked singularity coupled with quantum processes operating within a distance of the order of Planck length of the singularity will probably yield energy burst of the order of M_pc^2\\approx2\\times 10^{16} ergs, where M_p is the Planck mass.

H. M. Antia

1998-07-09T23:59:59.000Z

390

Gamma Ray Burst Neutrinos Probing Quantum Gravity  

E-Print Network (OSTI)

Very high energy, short wavelength, neutrinos may interact with the space-time foam predicted by theories of quantum gravity. They would propagate like light through a crystal lattice and be delayed, with the delay depending on the energy. This will appear to the observer as a violation of Lorenz invariance. Back of the envelope calculations imply that observations of neutrinos produced by gamma ray bursts may reach Planck-scale sensitivity. We revisit the problem considering two essential complications: the imprecise timing of the neutrinos associated with their poorly understood production mechanism in the source and the indirect nature of their energy measurement made by high energy neutrino telescopes.

M. C. Gonzalez-Garcia; F. Halzen

2006-11-28T23:59:59.000Z

391

Gamma ray bursts and spectral features  

Science Journals Connector (OSTI)

The situation concerning the presence of features in gamma ray burst (GRB) spectra is analyzed taking into account recent results obtained especially with the PHOBOS probes and GINGA satellite. If the existence of cyclotron features seems now to be generally accepted the situation for the other features reported around 400?500 keV is not completely clarified. The presence of such features is discussed. Moreover some aspects of the high and low energy variations in the GRB and on the characteristics of their total spectrum are also reviewed. Finally future missions which might have a great impact in the GRB spectral analysis will be shortly considered.

E. Jourdain

1991-01-01T23:59:59.000Z

392

Gamma Ray Bursts as Cosmological Probes  

Science Journals Connector (OSTI)

We discuss the prospects of using Gamma Ray Bursts (GRBs) as high?redshift distance estimators and consider their use in the study of two dark energy models the Generalized Chaplygin Gas (GCG) a model for the unification of dark energy and dark matter and the XCDM model a model where a generic dark energy fluid like component is described by the equation of state p = ??. Given that the GRBs range of redshifts is rather high it turns out that they are not very sensitive to the dark energy component being however fairly good estimators of the amount of dark matter in the Universe.

O. Bertolami; P. T. Silva

2006-01-01T23:59:59.000Z

393

Gamma Ray Bursts In Their Historic Context  

Science Journals Connector (OSTI)

Gamma ray bursts remained essentially non?understood or misunderstood from their 1973 discovery (not I will claim serendipitous) to the first 1997 redshift. This is by no means a record. The poster explored some of the examples of longer?standing puzzles and the after?dinner talk some of the details of the GRB case. The most striking feature of the GRB history is probably the unanimity with which all we like sheep went astray which followed the epoch of we have turned everyone to his own way. Some of the reasons for this the range of hypotheses and how GRBs were presented to the astronomical and larger communities are discussed.

Virginia Trimble

2004-01-01T23:59:59.000Z

394

13 - X-ray and Neutron Scattering  

Science Journals Connector (OSTI)

Abstract This chapter describes the use of neutrons and X-rays as probes in the study of structural and dynamic properties of metallic materials. Crystalline materials are characterized by their diffraction peaks related to their average crystallographic structure. In real crystals, locally displaced atoms and chemically (or isotopically for neutrons) different species may lead not only to changes of peak shapes and positions, but also to additional (diffuse) scattering between Bragg peak, including scattering around the primary beam (small-angle scattering). All these features can be used to extract information about the state of a sample, its compositional and structural variations on a scale depending on the scattering, in static and time-resolved kinetic studies. Energy-resolved scattering also offers an insight into solid-state dynamics on a microscopic scale. Some of the most important methods will be described and illustrated by instructive examples. The presentation offers a combined view of neutron and X-ray scattering, with the necessary simplifications dictated by space limitations. The special properties of thermal neutrons and of hard X-rays (now widely available at synchrotron radiation sources), their mutual combination, and combinations with other methods, in particular electron microscopy, offer ample opportunity to better understand and control materials properties. After a brief introduction to scattering from real crystals and some general ideas about long-range strains and Bragg peaks, the vicinity of Bragg peaks (displacement scattering at large scattering angles), the scattering far away from Bragg peaks (chemical heterogeneities, short-range order), and, in greater detail, small-angle scattering (which is not sensitive to the extent of crystallinity, but to nanoscale variations of chemical composition and of magnetization, precipitation) will be described, along with classical and more recent applications related to short-range ordering and precipitation in bulk and nanostructured alloys. Some other fields are only briefly addressed (grazing-incidence studies of surfaces, radiography, absorption spectroscopies, coherent X-rays). The final section offers some information on the influence of defects on lattice dynamics and on (slow) diffusive motion in materials.

Gernot Kostorz

2014-01-01T23:59:59.000Z

395

Neutrino Event Rates from Gamma Ray Bursts  

E-Print Network (OSTI)

We recalculate the diffuse flux of high energy neutrinos produced by Gamma Ray Bursts (GRB) in the relativistic fireball model. Although we confirm that the average single burst produces only ~10^{-2} high energy neutrino events in a detector with 1 km^2 effective area, i.e. about 10 events per year, we show that the observed rate is dominated by burst-to-burst fluctuations which are very large. We find event rates that are expected to be larger by one order of magnitude, likely more, which are dominated by a few very bright bursts. This greatly simplifies their detection.

F. Halzen; D. W. Hooper

1999-08-12T23:59:59.000Z

396

Gravity, Cosmic Rays and the LHC  

E-Print Network (OSTI)

The high energy proton beams expected when the Large Hadron Collider (LHC) comes online should provide a pass/fail test for a gravity-related explanation of ultrahigh energy cosmic rays. The model predicts that particles have two kinds energies, equal for null gravitational potentials and, in the potential at the Earth, differing significantly above one TeV. If correct, a 7 TeV trajectory energy proton at the LHC would deliver a 23.5 TeV particle state energy in a collision.

Richard Shurtleff

2008-01-20T23:59:59.000Z

397

A novel paradigm for short gamma-ray bursts with extended X-ray emission  

E-Print Network (OSTI)

The merger of a binary of neutron stars provides natural explanations for many of the features of short gamma-ray bursts (SGRBs), such as the generation of a hot torus orbiting a rapidly rotating black hole, which can then build a magnetic jet and provide the energy reservoir to launch a relativistic outflow. Yet, this scenario has problems explaining the recently discovered long-term and sustained X-ray emission associated with the afterglows of a subclass of SGRBs. We propose a new model that explains how an X-ray afterglow can be sustained by the product of the merger and how the X-ray emission is produced before the corresponding emission in the gamma-band, although it is observed to follow it. Overall, our paradigm combines in a novel manner a number of well-established features of the emission in SGRBs and results from simulations. Because it involves the propagation of an ultra-relativistic outflow and its interaction with a confining medium, the paradigm also highlights a unifying phenomenology between short and long GRBs.

Luciano Rezzolla; Pawan Kumar

2015-01-21T23:59:59.000Z

398

Very high-energy gamma rays from gamma-ray bursts  

Science Journals Connector (OSTI)

...which means that the energy thresholds of such...detecting gamma rays with energies as low as 30GeV...there have been two solar arrays in operation: STACEE in New Mexico (Hanna et al. 2002...not based around a solar array, employs rather...airshower arrays If the energy of the incoming gamma...

2007-01-01T23:59:59.000Z

399

Possible association of ultra-high-energy cosmic-ray events with strong gamma-ray bursts  

E-Print Network (OSTI)

We point out that each of the error boxes of the two highest-energy cosmic-ray shower events known, overlaps with that of a strong gamma-ray burst (GRB). The GRBs precede the cosmic rays by 5.5, and 11 months respectively. In one case the strongest known cosmic ray is paired with the strongest gamma-ray burst in the BATSE catalogue. The probability of this to have occurred by chance seems rather small. Without building on post-factum statistics, we think the above is remarkable enough to suggest that the cosmic ray and gamma-ray burst were produced by the same outburst. A time delay (and a small positional disparity) is expected, since the trajectory of a charged cosmic-ray particle is wriggled by intervening magnetic fields. We estimate that the Galaxy's field alone may produce a delay of the order observed. We discuss some of the implications that follow if such an association is confirmed. For example, the upper limit on the distance to the cosmic-ray source, combined with a much-better-determined position of the gamma-ray burst source, narrows greatly the volume in which to look for an optical counterpart. There is also useful information in the time delay regarding, e.g., intergalactic magnetic fields.

Mordehai Milgrom; Vladimir Usov

1995-05-03T23:59:59.000Z

400

RYLLA. [X-ray transport code  

SciTech Connect

This paper describes a computer code, RYLLA, which models the deposition of x-rays into thin metal slabs, and transports the resulting photoelectrons, finding the distribution of electrons leaving the slab from both the front and back surfaces. The slab must be homogeneous, but can contain a mixture of up to 5 different elements. Due to the short electron mean free path at low electron energies, RYLLA should be used only for studying thin slabs, roughly < 100 mg/cm/sup 2/ for low Z metals, and < 10 mg/cm/sup 2/ for high Z metals. X-ray energies should be in the range of 1 to 150 keV, as they are deposited only via photoionization and Compton scattering processes. Following photoionization, a hole exists in the electron cloud of the absorbing atom. This fills either by Auger or fluoresence, resulting in lower energy holes which are also filled. Fluoresence photons are transported and absorbed in the same manner as the primary photons, except that they are isotropically produced. Once all photons have been transported and absorbed, and all holes have been filled, a space- and energy-dependent electron source spectrum has been obtained. This is used in a discrete ordinate expansion solution of the 1-D transport equation, which gives the output electron spectra at the two slab surfaces. This paper discusses both the physics and coding of RYLLA. Examples of user input are given, as are some comparisons with other codes.

Hyde, R.A.

1983-06-08T23:59:59.000Z

Note: This page contains sample records for the topic "ray 202-586-5077 tosha" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Gamma Ray Bursts and Their Afterglows  

Science Journals Connector (OSTI)

Gamma?Ray Bursts are extreme astrophysical events which emit the bulk of their energy as photons in the 0.1 1.0 MeV range and whose durations span milliseconds to tens of minutes. They are formed in extreme relativistic outflows with Lorentz factors of hundreds and reside at cosmological distances. They are followed by X?ray optical and radio afterglows which can be observed for over a year after the event. Observations of afterglows showed that the emission is from jets and when corrected for this geometry the energies of GRBs appear to cluster around 5 1050 erg very comparable to that of supernovae. Evidence in the last several years shows that a significant fraction of long GRBs are related to a peculiar type of supernova explosions. These supernovae most likely mark the birth events of stellar mass black holes as the final products of the evolution of very massive stars. Short bursts are still somewhat mysterious but it is known that some of them are produced by an old population of stars. Neutron star merger is a leading candidate as the progenitor of short GRBs.

Reem Sari

2006-01-01T23:59:59.000Z

402

X-Ray Diffraction on NIF  

SciTech Connect

The National Ignition Facility (NIF) is currently a 192 beam, 1.6 MJ laser. NIF Ramp-Compression Experiments have already made the relevant exo-planet pressure range from 1 to 50 Mbar accessible. We Proposed to Study Carbon Phases by X-Ray Diffraction on NIF. Just a few years ago, ultra-high pressure phase diagrams for materials were very 'simple'. New experiments and theories point out surprising and decidedly complex behavior at the highest pressures considered. High pressures phases of aluminum are also predicted to be complex. Recent metadynamics survey of carbon proposed a dynamic pathway among multiple phases. We need to develop diagnostics and techniques to explore this new regime of highly compressed matter science. X-Ray Diffraction - Understand the phase diagram/EOS/strength/texture of materials to 10's of Mbar. Strategy and physics goals: (1) Powder diffraction; (2) Begin with diamond; (3) Continue with metals etc.; (4) Explore phase diagrams; (5) Develop liquid diffraction; and (6) Reduce background/improve resolution.

Eggert, J H; Wark, J

2012-02-15T23:59:59.000Z

403

Ray River Geothermal Area | Open Energy Information  

Open Energy Info (EERE)

Page Page Edit with form History Facebook icon Twitter icon » Ray River Geothermal Area Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Geothermal Resource Area: Ray River Geothermal Area Contents 1 Area Overview 2 History and Infrastructure 3 Regulatory and Environmental Issues 4 Exploration History 5 Well Field Description 6 Geology of the Area 7 Geofluid Geochemistry 8 NEPA-Related Analyses (0) 9 Exploration Activities (0) 10 References Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"TERRAIN","zoom":6,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"500px","height":"300px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":65.96202521,"lon":-150.9200119,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

404

Photon Sciences | Beamlines | IXS: Inelastic X-ray Scattering  

NLE Websites -- All DOE Office Websites (Extended Search)

IXS: Inelastic X-ray Scattering IXS: Inelastic X-ray Scattering Poster | Fact Sheet | Preliminary Design Report Scientific Scope Many hot topics related to the high frequency dynamics of condensed matter require both a narrower and steeper resolution function and access to a broader dynamic range than what are currently available. This represents a sort of "no man's land" that falls right in the dynamic gap lying between the high frequency spectroscopies, such as inelastic x-ray scattering (IXS), and the low frequency ones. New IXS spectrometers with improved energy and momentum resolutions would be required to fill this gap. To achieve this goal, a new x-ray optics concept for both the monochromatization and energy analysis of x-rays will be implemented at the NSLS-II Inelastic X-ray Scattering beamline. This solution exploits the

405

X-Ray Fluorescence (XRF) | Open Energy Information  

Open Energy Info (EERE)

X-Ray Fluorescence (XRF) X-Ray Fluorescence (XRF) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: X-Ray Fluorescence (XRF) Details Activities (0) Areas (0) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Lab Analysis Techniques Exploration Sub Group: Rock Lab Analysis Parent Exploration Technique: Rock Lab Analysis Information Provided by Technique Lithology: Bulk and trace element analysis of rocks, minerals, and sediments. Stratigraphic/Structural: Hydrological: Thermal: Dictionary.png X-Ray Fluorescence (XRF): X-Ray Fluorescence is a lab-based technique used for bulk chemical analysis of rock, mineral, sediment, and fluid samples. The technique depends on the fundamental principles of x-ray interactions with solid materials, similar

406

X-Ray Diffraction Microscopy of Magnetic Structures  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Diffraction Microscopy of Magnetic Structures Print X-Ray Diffraction Microscopy of Magnetic Structures Print science brief icon Scientists working at ALS Beamline 12.0.2.2 have demonstrated a new x-ray technique for producing short-exposure nanoscale images of the magnetic structure of materials. The new method combines aspects of coherent x-ray diffraction, which can determine 3-D charge distributions, and resonant magnetic scattering, which is sensitive to magnetic structures. Physicists have used coherent x-ray diffraction to measure the electron density of complicated molecules. The formula used to make these calculations contains terms that relate to the electron spin of magnetic atoms, but these terms are traditionally ignored since coherent x-ray diffraction has not been used to retrieve magnetic information. Using the full formula allows for the determination of not only the electron density, but also the magnetic spin distribution and its orientation.

407

Biological Imaging by Soft X-Ray Diffraction Microscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Biological Imaging by Soft X-Ray Diffraction Microscopy Print Biological Imaging by Soft X-Ray Diffraction Microscopy Print Electron and x-ray microscopes are a valuable tool for both the life and materials sciences, but they are limited in their ability to image with nanometer-scale resolution in three dimensions nonperiodic objects that are several microns in size. To fill this gap, the technique of coherent x-ray diffraction imaging now under development takes advantage of the penetrating power of x rays while simultaneously removing the limitations imposed by lens-based optical systems. Researchers from Stony Brook University, in collaboration with scientists at the ALS and Cornell University, have taken a large step in this direction by using a lensless x-ray diffraction microscope to image a freeze-dried yeast cell to better than 30-nm resolution. Images were made at several angular orientations of the cell.

408

APS 7-BM Beamline: X-Ray Resources  

NLE Websites -- All DOE Office Websites (Extended Search)

Useful Websites Useful Websites X-Ray Interactions with Matter from CRXO at LBNL. Intuitive interface for x-ray transmission and reflectivity for a wide range of materials. X-Ray Data Booklet from LBNL. Slightly outdated in places, but many useful tables of edge energies, fluorescence lines, and crystal lattice spacings. NIST XCOM Database. Powerful database of photoelectric absorption, elastic scattering, and Compton scattering cross-sections for a wide range of materials. X-Ray Server. Maintained by Sergey Stepanov at GMCA at the APS, this website has several powerful calculators for simulating x-ray reflection and diffraction. Software X-Ray Oriented Programs (XOP). This program, written by scientists at the ESRF and APS, is widely used in the synchrotron research community.

409

Biological Imaging by Soft X-Ray Diffraction Microscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Biological Imaging by Soft X-Ray Diffraction Microscopy Print Biological Imaging by Soft X-Ray Diffraction Microscopy Print Electron and x-ray microscopes are a valuable tool for both the life and materials sciences, but they are limited in their ability to image with nanometer-scale resolution in three dimensions nonperiodic objects that are several microns in size. To fill this gap, the technique of coherent x-ray diffraction imaging now under development takes advantage of the penetrating power of x rays while simultaneously removing the limitations imposed by lens-based optical systems. Researchers from Stony Brook University, in collaboration with scientists at the ALS and Cornell University, have taken a large step in this direction by using a lensless x-ray diffraction microscope to image a freeze-dried yeast cell to better than 30-nm resolution. Images were made at several angular orientations of the cell.

410

X-Ray Diffraction Microscopy of Magnetic Structures  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Diffraction Microscopy of Magnetic Structures Print X-Ray Diffraction Microscopy of Magnetic Structures Print science brief icon Scientists working at ALS Beamline 12.0.2.2 have demonstrated a new x-ray technique for producing short-exposure nanoscale images of the magnetic structure of materials. The new method combines aspects of coherent x-ray diffraction, which can determine 3-D charge distributions, and resonant magnetic scattering, which is sensitive to magnetic structures. Physicists have used coherent x-ray diffraction to measure the electron density of complicated molecules. The formula used to make these calculations contains terms that relate to the electron spin of magnetic atoms, but these terms are traditionally ignored since coherent x-ray diffraction has not been used to retrieve magnetic information. Using the full formula allows for the determination of not only the electron density, but also the magnetic spin distribution and its orientation.

411

Biological Imaging by Soft X-Ray Diffraction Microscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Biological Imaging by Soft X-Ray Diffraction Microscopy Print Biological Imaging by Soft X-Ray Diffraction Microscopy Print Electron and x-ray microscopes are a valuable tool for both the life and materials sciences, but they are limited in their ability to image with nanometer-scale resolution in three dimensions nonperiodic objects that are several microns in size. To fill this gap, the technique of coherent x-ray diffraction imaging now under development takes advantage of the penetrating power of x rays while simultaneously removing the limitations imposed by lens-based optical systems. Researchers from Stony Brook University, in collaboration with scientists at the ALS and Cornell University, have taken a large step in this direction by using a lensless x-ray diffraction microscope to image a freeze-dried yeast cell to better than 30-nm resolution. Images were made at several angular orientations of the cell.

412

Definition: X-Ray Diffraction (XRD) | Open Energy Information  

Open Energy Info (EERE)

X-Ray Diffraction (XRD) X-Ray Diffraction (XRD) Jump to: navigation, search Dictionary.png X-Ray Diffraction (XRD) X-Ray Diffraction (XRD) is a laboratory-based technique commonly used for identification of crystalline materials and analysis of unit cell dimensions. One of two primary types of XRD analysis (X-ray powder diffraction and single-crystal XRD) is commonly applied to samples to obtain specific information about the crystalline material under investigation. X-ray powder diffraction is widely used in geology, environmental science, material science, and engineering to rapidly identify unknown crystalline substances (typically in less than 20 minutes). A pure, finely ground, and homogenized sample is required for determination of the bulk composition. Additional uses include detailed

413

X-Ray Diffraction Microscopy of Magnetic Structures  

NLE Websites -- All DOE Office Websites (Extended Search)

X-Ray Diffraction Microscopy of Magnetic Structures Print X-Ray Diffraction Microscopy of Magnetic Structures Print science brief icon Scientists working at ALS Beamline 12.0.2.2 have demonstrated a new x-ray technique for producing short-exposure nanoscale images of the magnetic structure of materials. The new method combines aspects of coherent x-ray diffraction, which can determine 3-D charge distributions, and resonant magnetic scattering, which is sensitive to magnetic structures. Physicists have used coherent x-ray diffraction to measure the electron density of complicated molecules. The formula used to make these calculations contains terms that relate to the electron spin of magnetic atoms, but these terms are traditionally ignored since coherent x-ray diffraction has not been used to retrieve magnetic information. Using the full formula allows for the determination of not only the electron density, but also the magnetic spin distribution and its orientation.

414

X-Ray Diffraction (XRD) | Open Energy Information  

Open Energy Info (EERE)

X-Ray Diffraction (XRD) X-Ray Diffraction (XRD) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: X-Ray Diffraction (XRD) Details Activities (0) Areas (0) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Lab Analysis Techniques Exploration Sub Group: Rock Lab Analysis Parent Exploration Technique: Rock Lab Analysis Information Provided by Technique Lithology: Rapid and unambiguous identification of unknown minerals.[1] Stratigraphic/Structural: Hydrological: Thermal: Dictionary.png X-Ray Diffraction (XRD): X-Ray Diffraction (XRD) is a laboratory-based technique commonly used for identification of crystalline materials and analysis of unit cell dimensions. One of two primary types of XRD analysis (X-ray powder diffraction and single-crystal XRD) is commonly applied to samples to

415

Pulsar Wind Nebulae and Cosmic Rays: A Bedtime Story  

E-Print Network (OSTI)

The role pulsar wind nebulae play in producing our locally observed cosmic ray spectrum remains murky, yet intriguing. Pulsar wind nebulae are born and evolve in conjunction with SNRs, which are favored sites of Galactic cosmic ray acceleration. As a result they frequently complicate interpretation of the gamma-ray emission seen from SNRs. However, pulsar wind nebulae may also contribute directly to the local cosmic ray spectrum, particularly the leptonic component. This paper reviews the current thinking on pulsar wind nebulae and their connection to cosmic ray production from an observational perspective. It also considers how both future technologies and new ways of analyzing existing data can help us to better address the relevant theoretical questions. A number of key points will be illustrated with recent results from the VHE (E > 100 GeV) gamma-ray observatory VERITAS.

,

2014-01-01T23:59:59.000Z

416

Gamma-ray burst data from DMSP satellites  

SciTech Connect

A number of gamma-ray bursts have been detected by means of gamma-ray detectors aboard three Air Force Defense Meteorological Satellite Program (DMSP) satellites, in polar orbits at 800 km altitude. The gamma-ray data have a 2-second resolving time, and are usually telemetered in 5 energy bins in the range 50--1000 keV. Although it is not possible to detect gamma-ray bursts when the DMSP satellites are passing through the radiation belt or the South Atlantic Anomaly, or when the source is obscured by the Earth, a number of gamma-ray bursts have been detected by two or even three of the satellites. The DMSP data may be of considerable, assistance in evaluating time histories, locations, and spectra of gamma-ray bursts.

Terrell, J.; Klebesadel, R.W.; Lee, P. (Los Alamos National Lab., NM (United States)); Griffee, J.W. (Sandia National Labs., Albuquerque, NM (United States))

1991-01-01T23:59:59.000Z

417

Gamma-ray burst data from DMSP satellites  

SciTech Connect

A number of gamma-ray bursts have been detected by means of gamma-ray detectors aboard three Air Force Defense Meteorological Satellite Program (DMSP) satellites, in polar orbits at 800 km altitude. The gamma-ray data have a 2-second resolving time, and are usually telemetered in 5 energy bins in the range 50--1000 keV. Although it is not possible to detect gamma-ray bursts when the DMSP satellites are passing through the radiation belt or the South Atlantic Anomaly, or when the source is obscured by the Earth, a number of gamma-ray bursts have been detected by two or even three of the satellites. The DMSP data may be of considerable, assistance in evaluating time histories, locations, and spectra of gamma-ray bursts.

Terrell, J.; Klebesadel, R.W.; Lee, P. [Los Alamos National Lab., NM (United States); Griffee, J.W. [Sandia National Labs., Albuquerque, NM (United States)

1991-12-31T23:59:59.000Z

418

Density gradient free electron collisionally excited X-ray laser  

DOE Patents (OSTI)

An operational X-ray laser (30) is provided that amplifies 3p-3s transition X-ray radiation along an approximately linear path. The X-ray laser (30) is driven by a high power optical laser. The driving line focused optical laser beam (32) illuminates a free-standing thin foil (34) that may be associated with a substrate (36) for improved structural integrity. This illumination produces a generally cylindrically shaped plasma having an essentially uniform electron density and temperature, that exists over a long period of time, and provides the X-ray laser gain medium. The X-ray laser (30) may be driven by more than one optical laser beam (32, 44). The X-ray laser (30) has been successfully demonstrated to function in a series of experimental tests.

Campbell, Edward M. (Pleasanton, CA); Rosen, Mordecai D. (Berkeley, CA)

1989-01-01T23:59:59.000Z

419

Density gradient free electron collisionally excited x-ray laser  

DOE Patents (OSTI)

An operational x-ray laser is provided that amplifies 3p-3s transition x-ray radiation along an approximately linear path. The x-ray laser is driven by a high power optical laser. The driving line focused optical laser beam illuminates a free-standing thin foil that may be associated with a substrate for improved structural integrity. This illumination produces a generally cylindrically shaped plasma having an essentially uniform electron density and temperature, that exists over a long period of time, and provides the x-ray laser gain medium. The x-ray laser may be driven by more than one optical laser beam. The x-ray laser has been successfully demonstrated to function in a series of experimental tests.

Campbell, E.M.; Rosen, M.D.

1984-11-29T23:59:59.000Z

420

Formation of microbeam using tabletop soft X-ray laser  

Science Journals Connector (OSTI)

An X-ray microprobe with a sub-micron size beam and high intensity can provide X-ray analyses with a remarkable spatial resolution. We have performed focusing of an X-ray laser output into a sub-micron beam for the first time. In our experiment, an X-ray laser of Li-like Al 3d4f transition at 15.47 nm was delivered from an unstable cavity consisting of a concave mirror and a flat mirror with a square orifice of 100100 ?m in size. The beam from the orifice was then focused by using a Schwarzschild mirror coated with a Mo/Si multilayer. An X-ray beam size with a diameter of about 0.45 ?m and an estimated photon number of about 2106 photons per shot was achieved. Such sources could be well suited for the realization of X-ray microprobes.

Tadayuki Ohchi; Naohiro Yamaguchi; Chiemi Fujikawa; Tamio Hara

1999-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ray 202-586-5077 tosha" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Portable X-Ray Diffraction (XRD) | Open Energy Information  

Open Energy Info (EERE)

Portable X-Ray Diffraction (XRD) Portable X-Ray Diffraction (XRD) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Portable X-Ray Diffraction (XRD) Details Activities (0) Areas (0) Regions (0) NEPA(0) Exploration Technique Information Exploration Group: Field Techniques Exploration Sub Group: Data Collection and Mapping Parent Exploration Technique: Data Collection and Mapping Information Provided by Technique Lithology: Rapid and unambiguous identification of unknown minerals.[1] Stratigraphic/Structural: Hydrological: Thermal: Dictionary.png Portable X-Ray Diffraction (XRD): Portable X-Ray Diffraction (XRD) is a field-based technique that can be used for identification of crystalline materials and analysis of unit cell dimensions. Portable XRD analysis is similar to X-ray powder diffraction,

422

Biological Imaging by Soft X-Ray Diffraction Microscopy  

NLE Websites -- All DOE Office Websites (Extended Search)

Biological Imaging by Soft X-Ray Diffraction Microscopy Print Biological Imaging by Soft X-Ray Diffraction Microscopy Print Electron and x-ray microscopes are a valuable tool for both the life and materials sciences, but they are limited in their ability to image with nanometer-scale resolution in three dimensions nonperiodic objects that are several microns in size. To fill this gap, the technique of coherent x-ray diffraction imaging now under development takes advantage of the penetrating power of x rays while simultaneously removing the limitations imposed by lens-based optical systems. Researchers from Stony Brook University, in collaboration with scientists at the ALS and Cornell University, have taken a large step in this direction by using a lensless x-ray diffraction microscope to image a freeze-dried yeast cell to better than 30-nm resolution. Images were made at several angular orientations of the cell.

423

Gamma-ray Bursts as Probes of Galaxy Evolution  

E-Print Network (OSTI)

Gamma-ray Bursts as Probes of Galaxy Evolution Daniele Malesani, Dark Cosmology Centre and the X of the "Universe") #12;What is a gamma-ray burst? Brief (ms - min) and intense (~10-7 erg cm­2 s­1 ) burst of soft to ongoing star formation "Naked-eye" GRB 080319B GRBs explode within star-forming galaxies Gamma-ray bursts

?umer, Slobodan

424

Nuclear Criticality as a Contributor to Gamma Ray Burst Events  

E-Print Network (OSTI)

Most gamma ray bursts are able to be explained using supernovae related phenomenon. Some measured results still lack compelling explanations and a contributory cause from nuclear criticality is proposed. This is shown to have general properties consistent with various known gamma ray burst properties. The galactic origin of fast rise exponential decay gamma ray bursts is considered a strong candidate for these types of events.

Robert Bruce Hayes

2013-01-15T23:59:59.000Z

425

Gamma Ray Bursts with (and without) Supernova Fireworks  

Science Journals Connector (OSTI)

We review the observational status of the Supernova/Gamma?Ray Burst connection. Observations of long duration Gamma?ray bursts suggest that they are associated with bright SNe?Ic. However recent observations of GRB 060614 puzzle this scenario pointing out the existence of long?duration Gamma?ray Burst not accompanied by a bright supernova. Current estimates of the SN and GRB rates yield a ratio GRB/SNe?Ibc in the range ?0.4%3%.

Massimo Della Valle

2008-01-01T23:59:59.000Z

426

Gamma Ray Bursts, Neutron Star Quakes, and the Casimir Effect  

E-Print Network (OSTI)

We propose that the dynamic Casimir effect is a mechanism that converts the energy of neutron starquakes into $\\gamma$--rays. This mechanism efficiently produces photons from electromagnetic Casimir energy released by the rapid motion of a dielectric medium into a vacuum. Estimates based on the cutoff energy of the gamma ray bursts and the volume involved in a starquake indicate that the total gamma ray energy emission is consonant with observational requirements.

C. Carlson; T. Goldman; J. Perez-Mercader

1994-11-25T23:59:59.000Z

427

On The Origin of Very High Energy Cosmic Rays  

E-Print Network (OSTI)

We discuss the most recent developments in our understanding of the acceleration and propagation of cosmic rays up to the highest energies. In particular we specialize our discussion to three issues: 1) developments in the theory of particle acceleration at shock waves; 2) the transition from galactic to extragalactic cosmic rays; 3) implications of up-to-date observations for the origin of ultra high energy cosmic rays (UHECRs).

Pasquale Blasi

2005-11-08T23:59:59.000Z

428

Astrophysical Origins of the Highest Energy Cosmic Rays  

E-Print Network (OSTI)

Theoretical aspects of potential astrophysical sources of the highest energy cosmic rays are discussed, including their energy budget and some issues on particle escape and propagation. After briefly addressing AGN jets and GRBs, we highlight the possibility of heavy nuclei originating from cluster accretion shocks. The importance of X-ray and gamma-ray signatures in addition to neutrinos as diagnostic tools for source identification is emphasized.

Susumu Inoue

2007-02-01T23:59:59.000Z

429

Nonlinear optics with focused x-ray lasers  

SciTech Connect

We have investigated the possibility of focusing x-ray lasers with the use of multilayered mirrors or zone plates. The results indicate that x-ray intensities as high as 10{sup 14} W/cm{sup 2} can be achieved by focusing saturated Ne-like x-ray lasers. These intensities should be adequate for studying nonlinear optical phenomena. 9 refs., 2 figs.

DaSilva, L.B.; Muendel, M.H.; Falcone, R.W.; Fields, D.J.; Kortright, J.B.; MacGowan, B.J.; Matthews, D.L.; Mrowka, S.; Shimkaveg, G.M.; Trebes, J.E.

1990-12-12T23:59:59.000Z

430

Process and device for x-ray system quality assurance  

SciTech Connect

This invention relates to medical radiography test systems, and more particularly to a method and apparatus for providing evaluation of a medical or dental x-ray system consisting of x-ray generator, film and processor on a daily basis and to thereby assure the production of useful radiographs from the system with no need to repeat patient exposure because of problems with the x-ray system.

Van Pelt, W.F.; Peterson, R.W.

1982-11-10T23:59:59.000Z

431

The first X-ray diffraction measurements on Mars  

Science Journals Connector (OSTI)

The X-ray diffraction/X-ray fluorescence instrument CheMin on the Curiosity rover is a shoebox-sized device using transmission geometry and an energy-discriminating CCD detector. The instrument has returned the first X-ray diffraction data for soil and drilled samples from Mars outcrops, revealing a suite of primary basaltic minerals, amorphous components and varied hydrous alteration products including phyllosilicates.

Bish, D.

2014-10-21T23:59:59.000Z

432

On X-Ray Waveguiding in Nanochannels: Channeling Formalism  

E-Print Network (OSTI)

The question on X-ray extreme focusing (smallest reachable spot size) brings us to the idea for using the wave features of X-ray propagation in media. As known, wave features are revealed at propagation in ultra-narrow collimators as well as at glancing reflection from smooth flat and/or strongly curved surfaces. All these phenomena can be described within the general formalism of X-ray channeling.

S. B. Dabagov

2006-11-20T23:59:59.000Z

433

THE GEODESIC X-RAY TRANSFORM WITH FOLD CAUSTICS The ...  

E-Print Network (OSTI)

Aug 28, 2012 ... THE GEODESIC X-RAY TRANSFORM WITH FOLD CAUSTICS. PLAMEN STEFANOV AND GUNTHER UHLMANN. ABSTRACT. We give a...

2012-08-28T23:59:59.000Z

434

Inelastic X-ray and Nuclear Resonant Scattering  

NLE Websites -- All DOE Office Websites (Extended Search)

... Search About User Information News & Events Science & Education Beamlines Divisions Argonne Home > Advanced Photon Source > Inelastic X-ray and Nuclear Resonant Scattering...

435

Advances in X-Ray Diagnostics of Diesel Fuel Sprays  

Energy.gov (U.S. Department of Energy (DOE))

Recent advances in high-speed X-ray imaging has shown several distinct behaviors of commercial fuel injectors that cannot be seen with more conventional techniques.

436

Catching some rays: Organic solar cells make a leap forward ...  

NLE Websites -- All DOE Office Websites (Extended Search)

Additional resources Primer on solar power See also Argonne Now Magazine - Summer 2014 Argonne Now Magazine - Summer 2013 Solar Energy Research at Argonne Catching some rays:...

437

The origin of ultra high energy cosmic rays  

E-Print Network (OSTI)

We briefly discuss some open problems and recent developments in the investigation of the origin and propagation of ultra high energy cosmic rays (UHECRs).

Pasquale Blasi

2005-12-16T23:59:59.000Z

438

The Diverse Environments of Gamma-Ray Bursts.  

E-Print Network (OSTI)

??I present results from several years of concerted observations of the afterglows and host galaxies of gamma-ray bursts (GRBs), the most energetic explosions in the (more)

Perley, Daniel Alan

2011-01-01T23:59:59.000Z

439

A Closer Look at a Gamma-Ray Burst  

E-Print Network (OSTI)

A study of gamma rays produced when stars collapse or collide reveals details of the explosion mechanism, particularly the role of magnetic fields.

S. Covino

2007-05-05T23:59:59.000Z

440

New intraoral x-ray fluorographic imaging for dentistry  

SciTech Connect

A new dental x-ray fluorographic unit has been developed. This unit is composed of small intraoral x-ray tube, a compact x-ray image intensifier, and a high-resolution TV system. The purposes for developing this equipment were to (1) directly observe the tooth during endodontic procedures and (2) reduce x-ray exposure to the patient and the dentist. The radiation exposure can be reduced to about 1/600 the exposure used with conventional dental film. In clinical trials, a satisfactory fluorographic dental image for endodontic treatment was obtained with this new device.

Higashi, T.; Osada, T.; Aoyama, W.; Iguchi, M.; Suzuki, S.; Kanno, M.; Moriya, K.; Yoshimura, M.; Tusuda, M.

1983-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "ray 202-586-5077 tosha" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Normal incidence x-ray mirror for chemical microanalysis  

DOE Patents (OSTI)

An x-ray mirror for both electron column instruments and micro x-ray fluorescence instruments for making chemical, microanalysis comprises a non-planar mirror having, for example, a spherical reflecting surface for x-rays comprised of a predetermined number of alternating layers of high atomic number material and low atomic number material contiguously formed on a substrate and whose layers have a thickness which is a multiple of the wavelength being reflected. For electron column instruments, the wavelengths of interest lie above 1.5nm, while for x-ray fluorescence instruments, the range of interest is below 0.2nm. 4 figs.

Carr, M.J.; Romig, A.D. Jr.

1987-08-05T23:59:59.000Z

442

Self-terminating diffraction gates femtosecond X-ray nanocrystallograp...  

NLE Websites -- All DOE Office Websites (Extended Search)

Self-terminating diffraction gates femtosecond X-ray nanocrystallography measurements Authors: Barty, A., Caleman, C., Aquila, A., Timneanu, N., Lomb, L., White, T. A., Andreasson,...

443

Inelastic cross sections from gamma-ray measurements  

SciTech Connect

Measurements of gamma rays following neutron induced reactions have been studied with the Germanium Array for Neutron-induced Excitations (GEANIE) at the Los Alamos Neutron Science Center (LANSCE) for many years. Gamma-ray excitation functions and coincidence studies provide insight into nuclear reaction mechanisms as well as expanding our knowledge of energy levels and gamma-rays. Samples studied with Ge detectors at LANSCE range from Be to Pu. Fe, Cr and Ti have been considered for use as reference cross sections. An overview of the measurements and efforts to create a reliable neutron-induced gamma-ray reference cross section will be presented.

Nelson, Ronald Owen [Los Alamos National Laboratory

2010-12-06T23:59:59.000Z

444

Phase transition mastering for Blu-ray ROM disc  

Science Journals Connector (OSTI)

Phase Transition Mastering (PTM) has been developed for a 25 GB Blue-ray ROM Disc. The principle and the characteristics will be described in detail.

Osato, Kiyoshi

445

High intensity x-ray source using liquid gallium target  

DOE Patents (OSTI)

A high intensity x-ray source that uses a flowing stream of liquid gallium as a target with the electron beam impinging directly on the liquid metal.

Smither, Robert K. (Hinsdale, IL); Knapp, Gordon S. (Cupertino, CA); Westbrook, Edwin M. (Chicago, IL); Forster, George A. (Westmont, IL)

1990-01-01T23:59:59.000Z

446

X-ray Diffuse Scattering Measurements of Nucleation Dynamics...  

NLE Websites -- All DOE Office Websites (Extended Search)

X-ray Diffuse Scattering Measurements of Nucleation Dynamics at Femtosecond Resolution Real-time measurement and control of the non-equilibrium properties of materials represents...

447

XRMS: X-Ray Spectroscopy of Magnetic Solids  

NLE Websites -- All DOE Office Websites (Extended Search)

XRMS: X-Ray Spectroscopy of Magnetic Solids October 22-23, 2011 SLAC National Accelerator Laboratory, Menlo Park, CA More information...

448

X-ray absorption fine structure and magnetization characterization...  

NLE Websites -- All DOE Office Websites (Extended Search)

characterization of the metallic Co component in Co-doped ZnO thin films . X-ray absorption fine structure and magnetization characterization of the metallic Co...

449

The Collimation Signatures of Gamma-Ray Bursts: Jet Properties and Energetic Inferred from X-ray Afterglow Observations.  

E-Print Network (OSTI)

??Our understanding of gamma-ray bursts (GRBs) and their afterglows has progressed dramatically over the last few years thanks to the Swift mission and progress in (more)

Racusin, Judith

2009-01-01T23:59:59.000Z

450

Constraining Lorentz violations with Gamma Ray Bursts  

E-Print Network (OSTI)

Gamma ray bursts are excellent candidates to constrain physical models which break Lorentz symmetry. We consider deformed dispersion relations which break the boost invariance and lead to an energy-dependent speed of light. In these models, simultaneously emitted photons from cosmological sources reach Earth with a spectral time delay that depends on the symmetry breaking scale. We estimate the possible bounds which can be obtained by comparing the spectral time delays with the time resolution of available telescopes. We discuss the best strategy to reach the strongest bounds. We compute the probability of detecting bursts that improve the current bounds. The results are encouraging. Depending on the model, it is possible to build a detector that within several years will improve the present limits of 0.015 m_pl.

Maria Rodriguez Martinez; Tsvi Piran

2006-05-17T23:59:59.000Z

451

Lorentz invariance violation with gamma rays  

E-Print Network (OSTI)

The assumption of Lorentz invariance is one of the founding principles of Modern Physics and violation of it would have profound implications to our understanding of the universe. For instance, certain theories attempting a unified theory of quantum gravity predict there could be an effective refractive index of the vacuum; the introduction of an energy dependent dispersion to photons could in turn lead to an observable Lorentz invariance violation signature. Whilst a very small effect on local scales the effect will be cumulative, and so for very high energy particles that travel very large distances the difference in arrival times could become sufficiently large to be detectable. This proceedings will look at testing for such Lorentz invariance violation (LIV) signatures in the astronomical lightcurves of gamma-ray emitting objects, with particular notice being given to the prospects for LIV testing with, the next generation observatory, the Cherenkov Telescope Array.

Daniel, Michael

2015-01-01T23:59:59.000Z

452

X-ray Pinhole Camera Measurements  

SciTech Connect

The rod pinch diode is made up of a cathode plate and a small diameter anode rod that extends through the cathode hole. The anode is charged positively. The rod tip is made of a high-z material which is chosen for its bremsstrahlung efficiency. When the diode is pulsed it produces an intense x-ray source used for pulsed radiography. The baseline or reference diode consists of a 0.75 mm diameter Tungsten (W) tapered anode rod which extends 10 mm through a 9 mm diameter 3 mm thick aluminum (Al) aperture. The majority of the current in the electron beam is created on the edges of the cathode aperture and when properly configured, the electrons will self insulate, travel down the extension of the rod, and pinch onto the tip of the rod. In this presentation, performance of hybrid diodes will be compared with the baseline diode.

Nelson, D. S. [NSTec; Berninger, M. J. [NSTec; Flores, P. A. [NSTec; Good, D. E. [NSTec; Henderson, D. J. [NSTec; Hogge, K. W. [NSTec; Huber, S. R. [NSTec; Lutz, S. S. [NSTec; Mitchell, S. E. [NSTec; Howe, R. A. [NSTec; Mitton, C. V. [NSTec; Molina, I. [NSTec; Bozman, D. R. [SNL; Cordova, S. R. [SNL; Mitchell, D. R. [SNL; Oliver, B. V. [SNL; Ormond, E. C. [SNL

2013-06-20T23:59:59.000Z

453

The `excess' of primary cosmic ray electrons  

E-Print Network (OSTI)

With the accurate cosmic ray (CR) electron and positron spectra (denoted as $\\Phi_{\\rm e^{-}}$ and $\\Phi_{\\rm e^{+}}$, respectively) measured by AMS-02 collaboration, the difference between the electron and positron fluxes (i.e., $\\Delta \\Phi=\\Phi_{\\rm e^{-}}-\\Phi_{\\rm e^{+}}$), dominated by the propagated primary electrons, can be reliably inferred. In the standard model, the spectrum of propagated primary CR electrons at energies $\\geq 30$ GeV softens with the increase of energy. The absence of any evidence for such a continuous spectral softening in $\\Delta \\Phi$ strongly suggests a significant `excess' of primary CR electrons and at energies of $100-400$ GeV the identified excess component has a flux comparable to that of the observed positron excess. Middle-age but `nearby' supernova remnants (e.g., Monogem and Geminga) are favored sources for such an excess.

Li, Xiang; Lu, Bo-Qiang; Dong, Tie-Kuang; Fan, Yi-Zhong; Feng, Lei; Liu, Si-Ming; Chang, Jin

2014-01-01T23:59:59.000Z

454

Gray scale x-ray mask  

DOE Patents (OSTI)

The present invention describes a method for fabricating an embossing tool or an x-ray mask tool, providing microstructures that smoothly vary in height from point-to-point in etched substrates, i.e., structure which can vary in all three dimensions. The process uses a lithographic technique to transfer an image pattern in the surface of a silicon wafer by exposing and developing the resist and then etching the silicon substrate. Importantly, the photoresist is variably exposed so that when developed some of the resist layer remains. The remaining undeveloped resist acts as an etchant barrier to the reactive plasma used to etch the silicon substrate and therefore provides the ability etch structures of variable depths.

Morales, Alfredo M. (Livermore, CA); Gonzales, Marcela (Seattle, WA)

2006-03-07T23:59:59.000Z

455

Burning plasmas with ultrashort soft-x-ray flashing  

SciTech Connect

Fast ignition with narrow-band coherent x-ray pulses has been revisited for cryogenic deuterium-tritium (DT) plasma conditions achieved on the OMEGA Laser System. In contrast to using hard-x-rays (hv = 3-6 keV) proposed in the original x-ray fast-ignition proposal, we find that soft-x-ray sources with hv Almost-Equal-To 500 eV photons can be suitable for igniting the dense DT-plasmas achieved on OMEGA. Two-dimensional radiation-hydrodynamics simulations have identified the break-even conditions for realizing such a 'hybrid' ignition scheme (direct-drive compression with soft-x-ray heating) with 50-{mu}m-offset targets: {approx}10 ps soft-x-ray pulse (hv Almost-Equal-To 500 eV) with a total energy of 500-1000 J to be focused into a 10 {mu}m spot-size. A variety of x-ray pulse parameters have also been investigated for optimization. It is noted that an order of magnitude increase in neutron yield has been predicted even with x-ray energy as low as {approx}50 J. Scaling this idea to a 1 MJ large-scale target, a gain above {approx}30 can be reached with the same soft-x-ray pulse at 1.65 kJ energy. Even though such energetic x-ray sources do not currently exist, we hope that the proposed ignition scheme may stimulate efforts on generating powerful soft-x-ray sources in the near future.

Hu, S. X.; Goncharov, V. N.; Skupsky, S. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States)

2012-07-15T23:59:59.000Z

456

Low energy secondary cosmic ray flux (gamma rays) monitoring and its constrains  

E-Print Network (OSTI)

Temporal variation of secondary cosmic rays (SCR) flux was measured during the several full and new moon and days close to them at Department of Physics, University of Mumbai, Mumbai (Geomagnetic latitude: 10.6 N), India. The measurements were done by using NaI (Tl) scintillation detector with energy threshold of 200 keV. The SCR flux shows sudden enhancement for approximately about 2 hour in counts during couple of events out of all experimental observations. The maximum Enhancement SCR flux is about 200% as compared to the diurnal trend of SCR temporal variations. Weather parameters (temperature and relative humidity) were continuously monitored during all observation. The influences of geomagnetic field, interplanetary parameters and tidal effect on SCR flux have been considered. Summed spectra corresponding to enhancement duration indicates appearance of atmospheric radioactivity which shows single gamma ray line. Detail investigation revealed the presence of radioactive Ar 41 . This measurements puts lim...

Raghav, Anil; Yadav, Virendra; Bijewar, Nitinkumar

2014-01-01T23:59:59.000Z

457

Magnetic Structures in Gamma-Ray Burst Jets Probed by Gamma-Ray Polarization  

E-Print Network (OSTI)

We report polarization measurements in two prompt emissions of gamma-ray bursts, GRB 110301A and GRB 110721A, observed with the Gamma-ray burst polarimeter (GAP) aboard IKAROS solar sail mission. We detected linear polarization signals from each burst with polarization degree of $\\Pi = 70 \\pm 22$% with statistical significance of $3.7 \\sigma$ for GRB 110301A, and $\\Pi = 84^{+16}_{-28}$% with $3.3 \\sigma$ confidence level for GRB 110721A. We did not detect any significant change of polarization angle. These two events had shorter durations and dimmer brightness compared with GRB 100826A, which showed a significant change of polarization angle, as reported in Yonetoku et al. (2011). Synchrotron emission model can be consistent with all the data of the three GRBs, while photospheric quasi-thermal emission model is not favorable. We suggest that magnetic field structures in the emission region are globally-ordered fields advected from the central engine.

Daisuke Yonetoku; Toshio Murakami; Shuichi Gunji; Tatehiro Mihara; Kenji Toma; Yoshiyuki Morihara; Takuya Takahashi; Yudai Wakashima; Hajime Yonemochi; Tomonori Sakashita; Noriyuki Toukairin; Hirofumi Fujimoto; Yoshiki Kodama

2012-08-27T23:59:59.000Z

458

MAGNETIC STRUCTURES IN GAMMA-RAY BURST JETS PROBED BY GAMMA-RAY POLARIZATION  

SciTech Connect

We report polarization measurements in two prompt emissions of gamma-ray bursts, GRB 110301A and GRB 110721A, observed with the gamma-ray burst polarimeter (GAP) on borad the IKAROS solar sail mission. We detected linear polarization signals from each burst with polarization degree of {Pi} = 70 {+-} 22% with statistical significance of 3.7{sigma} for GRB 110301A, and {Pi} = 84{sup +16}{sub -28}% with 3.3{sigma} confidence level for GRB 110721A. We did not detect any significant change of polarization angle. These two events had shorter durations and dimmer brightness compared with GRB 100826A, which showed a significant change of polarization angle, as reported in Yonetoku et al. Synchrotron emission model can be consistent with the data of the three GRBs, while the photospheric quasi-thermal emission model is not favored. We suggest that magnetic field structures in the emission region are globally ordered fields advected from the central engine.

Yonetoku, Daisuke; Murakami, Toshio; Morihara, Yoshiyuki; Takahashi, Takuya; Wakashima, Yudai; Yonemochi, Hajime; Sakashita, Tomonori; Fujimoto, Hirofumi; Kodama, Yoshiki [College of Science and Engineering, School of Mathematics and Physics, Kanazawa University, Kakuma, Kanazawa, Ishikawa 920-1192 (Japan); Gunji, Shuichi; Toukairin, Noriyuki [Department of Physics, Faculty of Science, Yamagata University, 1-4-12, Koshirakawa, Yamagata, Yamagata 990-8560 (Japan); Mihara, Tatehiro [Cosmic Radiation Laboratory, RIKEN, 2-1, Hirosawa, Wako City, Saitama 351-0198 (Japan); Toma, Kenji, E-mail: yonetoku@astro.s.kanazawa-u.ac.jp [Department of Earth and Space Science, Osaka University, Toyonaka 560-0043 (Japan)

2012-10-10T23:59:59.000Z

459

Propagation of Cosmic Rays: Nuclear Physics in Cosmic-Ray Studies  

SciTech Connect

The nuclei fraction in cosmic rays (CR) far exceeds the fraction of other CR species, such as antiprotons, electrons, and positrons. Thus the majority of information obtained from CR studies is based on interpretation of isotopic abundances using CR propagation models where the nuclear data and isotopic production cross sections in p- and {alpha}-induced reactions are the key elements. This paper presents an introduction to the astrophysics of CR and diffuse {gamma}-rays and discusses some of the puzzles that have emerged recently due to more precise data and improved propagation models. Merging with cosmology and particle physics, astrophysics of CR has become a very dynamic field with a large potential of breakthrough and discoveries in the near future. Exploiting the data collected by the CR experiments to the fullest requires accurate nuclear cross sections.

Moskalenko, Igor V. [NASA/Goddard Space Flight Center, Code 661, Greenbelt, MD 20771 (United States); Joint Center for Astrophysics/University of Maryland, Baltimore County, Baltimore, MD 21250 (United States); Strong, Andrew W. [Max-Planck-Institut fuer extraterrestrische Physik, Postfach 1603, D-85740 Garching (Germany); Mashnik, Stepan G. [Los Alamos National Laboratory, Los Alamos, NM 87544 (United States)

2005-05-24T23:59:59.000Z

460

Muon Detection of TeV Gamma Rays from Gamma-Ray Bursts  

Science Journals Connector (OSTI)

Because of the limited size of the satellite-borne instruments, it has not been possible to observe the flux of gamma-ray bursts (GRBs) beyond GeV energy. We here show that it is possible to detect the GRB radiation of TeV energy and above by detecting the muon secondaries produced when the gamma rays shower in Earth's atmosphere. Observation is made possible by the recent commissioning of underground detectors (AMANDA, the Lake Baikal detector, and MILAGRO), which combine a low muon threshold of a few hundred GeV or less, with a large effective area of 103 m2 or more. Observations will not only provide new insights in the origin and characteristics of GRB, but they also will provide quantitative information on the diffuse infrared background.

J. Alvarez-Muiz; F. Halzen

1999-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "ray 202-586-5077 tosha" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

The Hard X-Ray to Gamma-ray Spectrum in the EGRET AGNs  

E-Print Network (OSTI)

EGRET (20 MeV to 30 GeV) on board the Compton GRO has observed high-energy emission from about 40-50 Active Galactic Nuclei. Theoretical models of this emission based on the upscattering of thermal disk photons by cooling, relativistic electrons can successfully account for the EGRET observations, but they predict a considerably greater X-ray flux than that actually observed in a majority of these sources. This inconsistency may be an indication that the particles are energized during the Compton scattering process, since the X-ray emission is produced by the lowest energy electrons, whose density may be relatively small due to the acceleration. Such a situation may arise as a result of resistive field generation in electromagnetic acceleration schemes, which we here explore. A key feature of this model is the assumed existence of a current associated with the azimuthal component B_phi of the underlying magnetic field by a slight imbalance in the energy distributions of outwardly moving, relativistic electrons and protons produced at the disk surface via shock acceleration. The generation of an electric field (via magnetic field line reconnection) is thus required to maintain the current in the presence of a resistivity induced by the radiative drag on the relativistic electrons. We show that the resulting spectrum can exhibit a significant deficit of X-rays compared with gamma-rays. In addition, due to the uni-directional flow of the current associated with B_phi, this model would predict that the electrons are energized relative to the protons in the outflow only on one side of the disk. They should be decelerated on the reverse side. As such, we would anticipate that any given blazar should have a ~50% probability of being gamma-bright, which appears to be consistent with the observed ratio.

Marco Fatuzzo; Fulvio Melia

1998-06-26T23:59:59.000Z

462

X-ray laser system, x-ray laser and method  

DOE Patents (OSTI)

Disclosed is an x-ray laser system comprising a laser containing generating means for emitting short wave length radiation, and means external to said laser for energizing said generating means, wherein when the laser is in an operative mode emitting radiation, the radiation has a transverse coherence length to width ratio of from about 0.05 to 1. Also disclosed is a method of adjusting the parameters of the laser to achieve the desired coherence length to laser width ratio.

London, Richard A. (Oakland, CA); Rosen, Mordecai D. (Berkeley, CA); Strauss, Moshe (Omer, IL)

1992-01-01T23:59:59.000Z

463

Coded aperture imaging system optimized for hard x-ray and gamma ray astronomy  

SciTech Connect

A coded aperture imaging system has been designed for the Gamma-Ray Imaging Spectrometer (GRIS). The system is optimized for imaging 511-keV positron-annihilation photons. For a galactic center 511-keV source strength of 10/sup -3/ cm/sup -2/s/sup -1/, the source location accuracy is expected to be +-0.2/sup 0/.

Gehrels, N.; Cline, T.L.; Huters, A.F.; Leventhal, M.; MacCallum, C.J.; Reber, J.D.; Stang, P.D.; Teegarden, B.J.; Tueller, J.

1985-01-01T23:59:59.000Z

464

Gamma-ray Astronomy: Implications for Fundamental Physics  

E-Print Network (OSTI)

Gamma-ray Astronomy studies cosmic accelerators through their electromagnetic radiation in the energy range between ~100 MeV and ~100 TeV. The present most sensitive observations in this energy band are performed, from space, by the Large Area Telescope onboard the Fermi satellite and, from Earth, by the Imaging Air Cherenkov Telescopes MAGIC, H.E.S.S. and VERITAS. These instruments have revolutionized the field of Gamma-ray Astronomy, discovering different populations of gamma-ray emitters and studying in detail the non-thermal astrophysical processes producing this high-energy radiation. The scientific objectives of these observatories include also questions of fundamental physics. With gamma-ray instruments we study the origin of Galactic cosmic rays, testing the hypothesis or whether they are mainly produced in supernova explosions. Also, we obtain the most sensitive measurement of the cosmic electron-positron spectrum between 20 GeV and 5 TeV. By observing the gamma-ray emission from sources at cosmological distances, we learn about the intensity and evolution of the extragalactic background light, and perform tests of Lorentz Invariance. Moreover, we can search for dark matter by looking for gamma-ray signals produced by its annihilation or decay in over-density sites. In this paper, we review the most recent results produced with the current generation of gamma-ray instruments in these fields of research.

Javier Rico

2011-11-28T23:59:59.000Z

465

Combined energy dispersive EXAFS and x?ray diffraction  

Science Journals Connector (OSTI)

An in situ experiment to measure both x?ray absorption spectroscopy and x?ray diffraction of aurichalcite is described. The experiment uses position sensitive detectors to enable both data sets to be collected while the sample is slowly decomposed in air and then reduced in hydrogen. ?

A. J. Dent; M. P. Wells; R. C. Farrow; C. A. Ramsdale; G. E. Derbyshire; G. N. Greaves; J. W. Couves; J. M. Thomas

1992-01-01T23:59:59.000Z

466

Fresnel and refractive lenses for X-rays  

Science Journals Connector (OSTI)

We present a Gaussian beam analysis of X-ray refractive and Fresnel lenses. The X-ray refractive lens is featured by an intrinsic soft (Gaussian) aperture due to strong absorption of X-rays by materials. We defined a parameter N0, the critical Fresnel number (CFN), to describe this optical property. The values of N0 for all practical materials are below 1000 for photon energies exceeding 30 eV, still lower for high-Z materials. The maximum effective Fresnel number of a lens is determined by its material to be 2N0 and its maximum enhancement of X-ray intensity is limited to (2?N0)2, independent of its shape. We found that the refractive lens is likely to be useful for manipulating nearly diffraction limited beam in the hard X-ray region and its application is severely restricted by available fabrication capabilities today. X-ray Fresnel lenses, both in cylindrical and linear forms, are proposed as superior focusing elements for hard X-rays. Their high efficiency, up to 100% in optimal construction, will enable us to manipulate beams with multiple lenses and obtain higher performance optics. Their design and fabrication are discussed in reference to those of X-ray Fresnel zone plates and micro Fresnel lenses for optoelectronics.

B.X. Yang

1993-01-01T23:59:59.000Z

467

X-ray attenuation properties of stainless steel (u)  

SciTech Connect

Stainless steel vessels are used to enclose solid materials for studying x-ray radiolysis that involves gas release from the materials. Commercially available stainless steel components are easily adapted to form a static or a dynamic condition to monitor the gas evolved from the solid materials during and after the x-ray irradiation. Experimental data published on the x-ray attenuation properties of stainless steel, however, are very scarce, especially over a wide range of x-ray energies. The objective of this work was to obtain experimental data that will be used to determine how a poly-energetic x-ray beam is attenuated by the stainless steel container wall. The data will also be used in conjunction with MCNP (Monte Carlos Nuclear Particle) modeling to develop an accurate method for determining energy absorbed in known solid samples contained in stainless steel vessels. In this study, experiments to measure the attenuation properties of stainless steel were performed for a range of bremsstrahlung x-ray beams with a maximum energy ranging from 150 keV to 10 MeV. Bremsstrahlung x-ray beams of these energies are commonly used in radiography of engineering and weapon components. The weapon surveillance community has a great interest in understanding how the x-rays in radiography affect short-term and long-term properties of weapon materials.

Wang, Lily L [Los Alamos National Laboratory; Berry, Phillip C [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

468

Shining Soft X-rays on Magnetic Structures  

Science Journals Connector (OSTI)

...2) demonstrate the power of x-ray magneto-optics in a synchroton study of single crystalline FePd layers, which provides...2) demonstrate the power of x-ray magneto-optics in a synchroton study of single crystalline FePd layers, which provides detailed...

Ulrich Hillebrecht

1999-06-25T23:59:59.000Z

469

Human genome sequencing with direct x-ray holographic imaging  

SciTech Connect

Direct holographic imaging of biological materials is widely applicable to the study of the structure, properties and action of genetic material. This particular application involves the sequencing of the human genome where prospective genomic imaging technology is composed of three subtechnologies, name an x-ray holographic camera, suitable chemistry and enzymology for the preparation of tagged DNA samples, and the illuminator in the form of an x-ray laser. We report appropriate x-ray camera, embodied by the instrument developed by MCR, is available and that suitable chemical and enzymatic procedures exist for the preparation of the necessary tagged DNA strands. Concerning the future development of the x-ray illuminator. We find that a practical small scale x-ray light source is indeed feasible. This outcome requires the use of unconventional physical processes in order to achieve the necessary power-compression in the amplifying medium. The understanding of these new physical mechanisms is developing rapidly. Importantly, although the x-ray source does not currently exist, the understanding of these new physical mechanisms is developing rapidly and the research has established the basic scaling laws that will determine the properties of the x-ray illuminator. When this x-ray source becomes available, an extremely rapid and cost effective instrument for 3-D imaging of biological materials can be applied to a wide range of biological structural assays, including the base-pair sequencing of the human genome and many questions regarding its higher levels of organization.

Rhodes, C.K.

1993-06-08T23:59:59.000Z

470

DEDUCING ELECTRON PROPERTIES FROM HARD X-RAY OBSERVATIONS  

E-Print Network (OSTI)

of the accelerated electron distribution. Keywords: Sun: flares; Sun: X-rays; Sun: acceleration; Sun: energetic distribution 31 4.5 Low-energy cutoffs in the electron distribution 32 4.6 Temperature distribution of thermal-ray emission process(es) in question with the electron distribution function, which is in turn a function

Piana, Michele

471

Terrestrial gamma ray flash production by active lightning leader channels  

E-Print Network (OSTI)

Terrestrial gamma ray flash production by active lightning leader channels B. E. Carlson,1 N. G 28 October 2010. [1] The production of terrestrial gamma ray flashes (TGFs) requires a seed energetic electron source and a strong electric field. Lightning leaders naturally provide seed electrons by cold

Bergen, Universitetet i

472

Twelfth National School on Neutron and X-ray Scattering  

E-Print Network (OSTI)

Twelfth National School on Neutron and X-ray Scattering June 12 � June 26, 2010 at Argonne National of the National School on Neutron and X-ray Scattering is to educate graduate students on the utilization of major National Laboratory's Neutron Scattering Science Division. Scientific Directors: Jonathan C. Lang, Suzanne

Pennycook, Steve

473

National School on Neutron and X-ray Scattering  

E-Print Network (OSTI)

National School on Neutron and X-ray Scattering May 30 � June 13, 2009 at Argonne National of the National School on Neutron and X-ray Scattering is to educate graduate students on the utilization of major National Laboratory's Neutron Scattering Science Division. Scientific Directors: Jonathan C. Lang, Suzanne

Pennycook, Steve

474

National School on Neutron and X-ray Scattering  

E-Print Network (OSTI)

15th National School on Neutron and X-ray Scattering August 10 - 24, 2013 at Argonne National of the National School on Neutron and X-ray Scattering is to educate graduate students on the utilization of major Ridge National Laboratory's Neutron Scattering Science Division. Scientific Directors: Jonathan C. Lang

475

Fourteenth National School on Neutron and X-ray Scattering  

E-Print Network (OSTI)

Fourteenth National School on Neutron and X-ray Scattering August 12 - 25, 2012 at Argonne National of the National School on Neutron and X-ray Scattering is to educate graduate students on the utilization of major Ridge National Laboratory's Neutron Scattering Science Division. Scientific Directors: Jonathan C. Lang

Pennycook, Steve

476

Thirteenth National School on Neutron and X-ray Scattering  

E-Print Network (OSTI)

Thirteenth National School on Neutron and X-ray Scattering June 11 ­ June 25, 2011 at Argonne of the National School on Neutron and X-ray Scattering is to educate graduate students on the utilization of major National Laboratory's Neutron Scattering Science Division. Scientific Directors: Jonathan C. Lang, Suzanne

477

Neutron and X-ray Scattering Study of Magnetic Manganites  

E-Print Network (OSTI)

Neutron and X-ray Scattering Study of Magnetic Manganites Graeme Eoin Johnstone A Thesis submitted are performed using a variety of neutron scattering and x-ray scattering techniques. The electronic ground for analysing the results of the polarised neutron scattering experiment. There are a large number of people who

Boothroyd, Andrew

478

Sixteenth National School on Neutron and X-ray Scattering  

E-Print Network (OSTI)

Sixteenth National School on Neutron and X-ray Scattering June 14-28, 2014 at Argonne National of the National School on Neutron and X-ray Scattering is to educate graduate students on the utilization of major's Neutron Scattering Science Division. Scientific Directors: Suzanne G.E. te Velthuis, Esen Ercan Alp

Pennycook, Steve

479

Tenth National School on Neutron and X-ray Scattering  

E-Print Network (OSTI)

Tenth National School on Neutron and X-ray Scattering September 24 - October 11, 2008 at Argonne of the National School on Neutron and X-ray Scattering is to educate graduate students on the utilization of major National Laboratory's Neutron Scattering Science Division. Scientific Directors: Jonathan C. Lang, Suzanne

Pennycook, Steve

480

X-ray spectra transmitted through Compton-thick absorbers  

E-Print Network (OSTI)

X-ray spectra transmitted through matter which is optically thick to Compton scattering are computed by means of Monte Carlo simulations. Applications to the BeppoSAX data of the Seyfert 2 galaxy in Circinus, and to the spectral modeling of the Cosmic X-ray Background, are discussed.

Giorgio Matt; Fulvio Pompilio; Fabio La Franca

1999-04-24T23:59:59.000Z

Note: This page contains sample records for the topic "ray 202-586-5077 tosha" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


481

Laser Copper Plasma X-ray Source Debris Characterization  

E-Print Network (OSTI)

Laser Copper Plasma X-ray Source Debris Characterization A Thesis Presented by David Hurley 3, 2007 Vice President for Research and Dean of Graduate studies #12;Abstract Laser copper plasma for x-ray lithography. Copper debris in the form of vapor, ions, dust, and high-speed particles

Huston, Dryver R.

482

Millisecond oscillations during thermonuclear X-ray bursts  

E-Print Network (OSTI)

I analyze 68 oscillation trains detected in a search of 159 thermonuclear bursts from eight neutron star X-ray binaries observed with the Rossi X-ray Timing Explorer. I use all data that were public as of September 2001. ...

Muno, Michael Patrick, 1975-

2002-01-01T23:59:59.000Z

483

Implications the VHE #Ray Spectral Variability M. Bttcher  

E-Print Network (OSTI)

luminosity limited wind accretion from companion and system viewed at an inclination angle i o emission limited wind accretion from the companion star the system is viewed inclination angle of i o emission: Gamma­rays: theory; radiation mechanisms: non­thermal; X­rays: binaries; winds, outflows PACS: 97.10.Gz

Boettcher, Markus

484

X rays following the alpha decay of Pa231  

Science Journals Connector (OSTI)

More detailed information is presented concerning the L and K x-ray spectra due to internal conversion of the electromagnetic transitions following the ? decay of Pa231. Some of the difficulties discussed in Ref. 1 are clarified by the new results.[RADIOACTIVITY Pa231; measured L and K Ac x-ray components, ?? and ?XL coin Ac227 deduced levels, ICC.

A. G. de Pinho; L. T. Auler; A. G. da Silva

1974-05-01T23:59:59.000Z

485

A computational model of the music of Stevie Ray Vaughan  

Science Journals Connector (OSTI)

Every musician who improvises has a unique musical vocabulary, which may be perceived in his or her compositions. In this paper, we explain our design of a computational model that predicts the creative decisions made by the blues musician, Stevie Ray ... Keywords: Stevie Ray Vaughan, computational modeling, creativity modeling, musical creativity, production system, schemas

Naresh Vempala; Subrata Dasgupta

2007-06-01T23:59:59.000Z

486

Neutrino and cosmic-ray emission from multiple internal shocks in gamma-ray bursts  

E-Print Network (OSTI)

In the classical theory of gamma-ray bursts, it is expected that particles are accelerated at mildly relativistic shocks generated by the collisions of material ejected from a central engine. We consider neutrino and cosmic-ray emission from multiple emission regions since these internal collisions must occur at very different radii, from below the photosphere all the way out to the circumburst medium, as a consequence of the efficient dissipation of kinetic energy. We demonstrate that the different messengers originate from different collision radii, which means that multimessenger observations open windows for revealing the evolving GRB outflows. We find that, even in the internal shock model, the neutrino production can be dominated by emission from around the photosphere, i.e., the radius where the ejecta become transparent to gamma-ray emission. Possible subphotospheric contributions enhance the detectability. We predict a minimal neutrino flux per flavor at the level of E^2 J ~ 10^{-11} GeV cm^{-2} sr^{...

Bustamante, Mauricio; Murase, Kohta; Winter, Walter

2014-01-01T23:59:59.000Z

487

Constraints on jet X-ray emission in low/hard state X-ray binaries  

E-Print Network (OSTI)

We show that the combination of the similarities between the X-ray properties of low luminosity accreting black holes and accreting neutron stars, combined with the differences in their radio properties argues that the X-rays from these systems are unlikely to be formed in the relativistic jets. Specifically, the spectra of extreme island state neutron stars and low/hard state black holes are known to be indistinguishable, while the power spectra from these systems are known to show only minor differences beyond what would be expected from scaling the characteristic variability frequencies by the mass of the compact object. The spectral and temporal similarities thus imply a common emission mechanism that has only minor deviations from having all key parameters scaling linearly with the mass of the compact object, while we show that this is inconsistent with the observations that the radio powers of neutron stars are typically about 30 times lower than those of black holes at the same X-ray luminosity. We also show that an abrupt luminosity change would be expected when a system makes a spectral state transition from a radiatively inefficient jet dominated accretion flow to a thin disk dominated flow, but that such a change is not seen.

Thomas J. Maccarone

2005-03-31T23:59:59.000Z

488

Isotropic star in low-mass X-ray binaries and X-ray pulsars  

E-Print Network (OSTI)

We present a model for compact stars in the low mass X-ray binaries(LMXBs) and X-ray pulsars using a metric given by John J. Matese and Patrick G. Whitman \\citep{Matese and Whitman1980}. Here the field equations are reduced to a system of two algebraic equations considering the isotropic pressure. Compact star candidates 4U 1820-30(radius=10km) in LMXBs, and Her X-1(radius=7.7km), SAX J 1808.4-3658(SS1)(radius=7.07km) and SAX J 1808.4-3658(SS2)(radius=6.35km) in X-ray pulsars satisfy all the energy conditions, TOV-equation and stability condition. From our model, we have derived mass($M$), central density($\\rho_{0}$), suface density($\\rho_{b}$), central pressure($p_{0}$), surface pressure($p_{b}$) and surface red-shift($Z_{s}$) of the above mentioned stars, which are very much consistant with the observed/reported datas\\citep{N. K. Glendenning1997,Gondek2000}. We have also observe the adiabatic index($\\gamma$>4/3) of the above steller objects.

Mehedi Kalam; Sk. Monowar Hossein; Sajahan Molla

2014-10-01T23:59:59.000Z

489

Femtosecond x-ray absorption spectroscopy with hard x-ray free electron laser  

SciTech Connect

We have developed a method of dispersive x-ray absorption spectroscopy with a hard x-ray free electron laser (XFEL), generated by a self-amplified spontaneous emission (SASE) mechanism. A transmission grating was utilized for splitting SASE-XFEL light, which has a relatively large bandwidth (?E/E ? 5 10{sup ?3}), into several branches. Two primary split beams were introduced into a dispersive spectrometer for measuring signal and reference spectra simultaneously. After normalization, we obtained a Zn K-edge absorption spectrum with a photon-energy range of 210 eV, which is in excellent agreement with that measured by a conventional wavelength-scanning method. From the analysis of the difference spectra, the noise ratio was evaluated to be ?3 10{sup ?3}, which is sufficiently small to trace minute changes in transient spectra induced by an ultrafast optical laser. This scheme enables us to perform single-shot, high-accuracy x-ray absorption spectroscopy with femtosecond time resolution.

Katayama, Tetsuo; Togashi, Tadashi; Tono, Kensuke; Kameshima, Takashi [Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan)] [Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Inubushi, Yuichi; Sato, Takahiro; Hatsui, Takaki; Yabashi, Makina [RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan)] [RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Obara, Yuki; Misawa, Kazuhiko [Department of Applied Physics, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588 (Japan)] [Department of Applied Physics, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588 (Japan); Bhattacharya, Atanu; Kurahashi, Naoya [Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502 (Japan)] [Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502 (Japan); Ogi, Yoshihiro [Molecular Reaction Dynamics Research Team, RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako 351-0198 (Japan)] [Molecular Reaction Dynamics Research Team, RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako 351-0198 (Japan); Suzuki, Toshinori [Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502 (Japan) [Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502 (Japan); Molecular Reaction Dynamics Research Team, RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako 351-0198 (Japan)

2013-09-23T23:59:59.000Z

490

Compton scattering effects on the duration of terrestrial gamma-ray flashes  

E-Print Network (OSTI)

; published 18 January 2012. [1] Terrestrial gamma-ray flashes (TGFs) are gamma-ray bursts detected from space) recently discovered by the gamma-ray burst monitor (GBM) aboard the Fermi Gamma-Ray Space Telescope. Introduction [2] Terrestrial gamma-ray flashes (TGFs) are bursts of high-energy photons originating from

Pasko, Victor

491

OBSERVATIONS OF THE PROMPT GAMMA-RAY EMISSION OF GRB 070125 Eric C. Bellm,1  

E-Print Network (OSTI)

2007 November 13; accepted 2008 July 25 ABSTRACT The long, bright gamma-ray burst GRB 070125: gamma rays: bursts 1. INTRODUCTION The prompt gamma-ray emission of gamma-ray bursts (GRBs) is the mostOBSERVATIONS OF THE PROMPT GAMMA-RAY EMISSION OF GRB 070125 Eric C. Bellm,1 Kevin Hurley,1 Valentin

California at Berkeley, University of

492

Study of Celestial Objects with Very High Energy Gamma Rays CANGAROO III  

E-Print Network (OSTI)

), the doppler boosting of secondary gamma-rays is sufficient to produce TeV gamma-rays. Gamma-ray bursts: Fireballs expanding with relativistic speed explain gamma-ray bursts at cosmological distancesStudy of Celestial Objects with Very High Energy Gamma Rays CANGAROO III Project Description

Enomoto, Ryoji

493

Ivan De Mitri VHE Gamma Ray Astronomy 1 Very High Energy  

E-Print Network (OSTI)

~ 1/day Gamma Ray Bursts The X-ray counterpart detection with better pointing accuracy instrumentsIvan De Mitri VHE Gamma Ray Astronomy 1 Very High Energy Gamma Ray Astronomy Ivan De Mitri'Aquila, 11- Jun -2002 Photo F. Arneodo #12;Ivan De Mitri VHE Gamma Ray Astronomy 2 Seminar Outline Background

Harrison, Thomas

494

X-RAYRICH GAMMA-RAY BURSTS, PHOTOSPHERES, AND VARIABILITY P. Meszaros,1,2  

E-Print Network (OSTI)

X-RAY­RICH GAMMA-RAY BURSTS, PHOTOSPHERES, AND VARIABILITY P. Me´sza´ros,1,2 E. Ramirez-Ruiz,3 M. J of the observational gamma-ray variability-luminosity relation. Subject headings: gamma rays: bursts -- radiation mechanisms: nonthermal 1. INTRODUCTION Gamma-ray burst (GRB) light curves at gamma-ray ener- gies are often

Zhang, Bing

495

Search for GeV Emission from Gamma-Ray Bursts Using Milagro Scaler Data  

E-Print Network (OSTI)

Search for GeV Emission from Gamma-Ray Bursts Using Milagro Scaler Data D. A. Williams to search for high energy emission from a sample of 98 gamma-ray bursts (GRB) detected from January 2000: gamma-ray sources; gamma-ray bursts; astronomical observations: gamma-ray PACS: 98.70.Rz,95.85.Pw Air

California at Santa Cruz, University of

496

PoGO : The Polarised Gamma-ray Observer S. Larssona  

E-Print Network (OSTI)

. Recently, the detection of high linear polarisation, (80±20)%, in a gamma ray burst ob- served, this observation will have far reaching implications for models of gamma- ray bursts. Many of the X-ray and gamma-ray1 PoGO : The Polarised Gamma-ray Observer S. Larssona and M. Pearceb (for the PoGO Collaboration

Haviland, David

497

SOFT X-RAY EMISSIONS FROM PLANETS, MOONS, AND COMETS A. Bhardwaj(1)  

E-Print Network (OSTI)

SOFT X-RAY EMISSIONS FROM PLANETS, MOONS, AND COMETS A. Bhardwaj(1) , G. R. Gladstone(2) , R. F to radiate in the soft x-ray energy ( the generation of soft x-rays from these objects, whereas in the hard x-ray energy range (>10 keV) x-rays mainly

Johnson, Robert E.

498

X-ray-induced phase transformation in congruent and vapor-transport-equilibrated lithium tantalate  

E-Print Network (OSTI)

X-ray-induced phase transformation in congruent and vapor-transport-equilibrated lithium tantalate an effect of a partially reversible x-ray-induced increase of diffuse x-ray scattering in both congruent been attributed to x-ray-induced decay of the ferroelectric phase at room temperature. The x-ray

Byer, Robert L.

499

Probing Spatial, Electronic Structures with X-ray Scattering, Spectroscopic  

NLE Websites -- All DOE Office Websites (Extended Search)

Probing Spatial, Electronic Structures with X-ray Scattering, Spectroscopic Probing Spatial, Electronic Structures with X-ray Scattering, Spectroscopic Techniques Wednesday, September 5, 2012 - 10:45am SLAC, Bldg. 137, Room 226 Gang Chen Seminar: Structures at atomic scales are traditionally determined through X-ray crystallography that amplifies scattering intensities by introducing spatial periodicity. For amorphous materials and many macromolecules, such as viruses, proteins and biofilms, it is hard to determine structures due to their incapability to crystallize or change of configuration during crystallization. In this talk, I will present the application of X-ray reflectivity and a newly developed fluctuation X-ray scattering technique to study the structures of lipid membranes and randomly oriented nanoparticles. Three different types of domain registrations occurring with

500

Resonant Soft X-Ray Scattering - Combining Structural with Spectroscopic  

NLE Websites -- All DOE Office Websites (Extended Search)

Resonant Soft X-Ray Scattering - Combining Structural with Spectroscopic Resonant Soft X-Ray Scattering - Combining Structural with Spectroscopic Refinement Friday, September 28, 2012 - 10:00am SLAC, Bldg. 137, Room 322 SSRL Presents Kevin Stone X-ray absorption spectroscopy has become an important tool in understanding the electronic structure of materials. Resonant absorption edges in the soft x-ray regime are especially interesting as they allow the study of the lighter elements, such as in organic or organo-metallic substances, as well as important L-edges of the 3d transition metals important in magnetic and oxide systems. Measurements of soft x-ray absorption spectra are inherently surface sensitive, and are plagued by issues such as extinction (in electron yield measurements) or self absorption (in fluorescence yield