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Sample records for carbon-nanotube-based x-ray source

  1. Carbon nanotube based field emission X-ray sources

    NASA Astrophysics Data System (ADS)

    Cheng, Yuan

    This dissertation describes the development of field emission (FE) x-ray sources with a carbon-nanotube (CNT) cathode. Field emission x-rays have advantages over conventional x-rays by replacing the thermionic cathode with a cold cathode so that electrons are emitted at room temperature and emission is voltage controllable. CNTs are found to be excellent electron emitters with low threshold fields and high current density which makes them ideal for generate field emission x-rays. Macroscopic CNT cold cathodes are prepared and the parameters to tune their field emission properties are studied: structure and morphology of CNT cathodes, temperature as well as electronic work function of CNT. Macroscopic CNT cathodes with optimized performance are chosen to build a high-resolution x-ray imaging system. The system can readily generate x-ray radiation with continuous variation of temporal resolution up to nanoseconds and spatial resolution down to 10 micron. Its potential applications for dynamic x-ray imaging and micro-computed tomography are also demonstrated. The performance characteristics of this compact and versatile system are promising for non-destructive testing and for non-invasive small-animal imaging for biomedical research.

  2. Dynamic radiography using a carbon-nanotube-based field-emission x-ray source

    SciTech Connect

    Cheng, Y.; Zhang, J.; Lee, Y.Z.; Gao, B.; Dike, S.; Lin, W.; Lu, J.P.; Zhou, O.

    2004-10-01

    We report a dynamic radiography system with a carbon nanotube based field-emission microfocus x-ray source. The system can readily generate x-ray radiation with continuous variation of temporal resolution as short as nanoseconds. Its potential applications for dynamic x-ray imaging are demonstrated. The performance characteristics of this compact and versatile system are promising for noninvasive imaging in biomedical research and industrial inspection.

  3. Electron optics simulation for designing carbon nanotube based field emission x-ray source

    NASA Astrophysics Data System (ADS)

    Sultana, Shabana

    In this dissertation, electron optics simulation for designing carbon nanotube (CNT) based field emission x-ray source for medical imaging applications will be presented. However, for design optimization of x-ray tubes accurate electron beam optics simulation is essential. To facilitate design of CNT x-ray sources a commercial 3D finite element software has been chosen for extensive simulation. The results show that a simplified model of uniform electron field emission from the cathode surface is not sufficient when compared to experimental measurements. This necessitated the development of a refined model to describe a macroscopic field emission CNT cathode for electron beam optics simulations. The model emulates the random distribution of CNTs and the associated variation of local field enhancement factor. The main parameter of the model has been derived empirically from the experimentally measured I-V characteristics of the CNT cathode. Simulation results based on this model agree well with experiments which include measurements of the transmission rate and focus spot size. The model provides a consistent simulation platform for optimization of electron beam optics in CNT x-ray source design. A systematic study of electron beam optics in CNT x-ray tubes led to the development of a new generation of compact x-ray source with multiple pixels. A micro focus field emission x-ray source with a variable focal spot size has been fully characterized and evaluated. It has been built and successfully integrated into micro-CT scanners which are capable of dynamic cardiac imaging of free-breathing small animals with high spatial and temporal resolutions. In addition a spatially distributed high power multi-beam x-ray source has also been designed and integrated into a stationary digital breast tomosynthesis (s-DBT) configuration. This system has the potential to reduce the total scan time to 4 seconds and yield superior image quality in breast imaging.

  4. Development of tomographic imaging systems using carbon-nanotube-based field-emission x-ray sources

    NASA Astrophysics Data System (ADS)

    Zhang, Jian

    2005-11-01

    Conventional thermionic x-ray sources use hot filament cathodes to generate electrons for x-ray production. The thermionic technology has several inherent limitations such as high operating temperature, slow response time, and difficulty for miniaturization. On the other hand, field emission provides an alternative to generate electrons without all these limitations. The concept of field emission x-ray source has been proposed and tested in the early 1970s. Unfortunately all of the early field emission x-ray systems failed due primarily to the limitations on the electron field emitters. Carbon nanotubes (CNT) have recently emerged as a promising class of electron emissive materials and field emission x-ray source based on CNTs are expected to have significantly improved properties. We have recently developed a CNT-based field emission micro-focus x-ray source. It shows stable tube current under high operating voltage, extraordinary dynamic imaging capability, and excellent potential for miniaturization. All of these new features make it very attractive for various potential industrial and medical applications. In order to demonstrate its applications, two sets of x-ray imaging systems using this field emission x-ray source were constructed in our lab. One is a micro-computed tomographic (micro-CT) imaging system using a single field emission x-ray source for dynamic radiographic and tomographic imaging applications. It shows great potential for the future development of dynamic micro-CT scanner. The other one is a multi-beam field emission x-ray source with multiple addressable focal spots which can provide scanning x-ray beams without mechanical movement. It can lead to fast data acquisition rates for future tomographic imaging systems with a simplified experimental set-up.

  5. Effect of a concave grid mesh in a carbon nanotube-based field emission X-ray source

    SciTech Connect

    Kim, Hyun Suk; Castro, Edward Joseph D.; Lee, Choong Hun

    2014-10-15

    Highlights: • Successful design using a concave grid mesh for the focusing electron. • Much better X-ray image due to the concave grid mesh. • Higher anode current efficiency using the concave grid mesh versus a flat grid mesh. - Abstract: This study introduces a simple approach to improve the X-ray image quality produced by the carbon nanotube (CNT) field emitter X-ray source by altering the geometrical shape of the grid mesh from the conventional flat shape to a concave one in a typical triode structure. The concave shape of the grid electrode increases the effective number of the grid cells in the mesh, which exerted an electric field in the direction of the emitted electrons, thereby increasing the emission current reaching the anode. Furthermore, the curved mesh (concave grid mesh), which was responsible for the extraction of electrons from the field emitter, exhibited a focusing effect on the electron beam trajectory thereby, reducing the focal spot size impinging on the anode and resulted in a better spatial resolution of the X-ray images produced.

  6. Carbon Nanotube Based Deuterium Ion Source for Improved Neutron Generators

    SciTech Connect

    Fink, R. L.; Jiang, N.; Thuesen, L.; Leung, K. N.; Antolak, A. J.

    2009-03-10

    Field ionization uses high electric fields to cause the ionization and emission of ions from the surface of a sharp electrode. We are developing a novel field ionization neutron generator using carbon nanotubes (CNT) to produce the deuterium ion current. The generator consists of three major components: a deuterium ion source made of carbon nanotubes, a smooth negatively-biased target electrode, and a secondary electron suppression system. When a negative high voltage is applied on the target electrode, a high gradient electric field is formed at the tips of the carbon nanotubes. This field is sufficiently strong to create deuterium (D) ions at or near the nanotubes which are accelerated to the target causing D-D reactions to occur and the production of neutrons. A cross magnetic field is used to suppress secondary emission electrons generated on the target surface. We have demonstrated field ionization currents of 70 nA (1 {mu}A/cm{sup 2}) at hydrogen gas pressure of 10 mTorr. We have found that the current scales proportionally with CNT area and also with the gas pressure in the range of 1 mTorr to 10 mTorr. We have demonstrated pulse cut-off times as short as 2 {mu}sec. Finally, we have shown the feasibility of generating neutrons using deuterium gas.

  7. A Multi-Walled Carbon Nanotube-based Biosensor for Monitoring Microcystin-LR in Sources of Drinking Water Supplies

    EPA Science Inventory

    A multi-walled carbon nanotube-based electrochemical biosensor is developed for monitoring microcystin-LR (MC-LR), a toxic cyanobacterial toxin, in sources of drinking water supplies. The biosensor electrodes are fabricated using dense, mm-long multi-walled CNT (MWCNT) arrays gro...

  8. X-ray lithography source

    DOEpatents

    Piestrup, Melvin A.; Boyers, David G.; Pincus, Cary

    1991-01-01

    A high-intensity, inexpensive X-ray source for X-ray lithography for the production of integrated circuits. Foil stacks are bombarded with a high-energy electron beam of 25 to 250 MeV to produce a flux of soft X-rays of 500 eV to 3 keV. Methods of increasing the total X-ray power and making the cross section of the X-ray beam uniform are described. Methods of obtaining the desired X-ray-beam field size, optimum frequency spectrum and elminating the neutron flux are all described. A method of obtaining a plurality of station operation is also described which makes the process more efficient and economical. The satisfying of these issues makes transition radiation an exellent moderate-priced X-ray source for lithography.

  9. X-ray lithography source

    DOEpatents

    Piestrup, M.A.; Boyers, D.G.; Pincus, C.

    1991-12-31

    A high-intensity, inexpensive X-ray source for X-ray lithography for the production of integrated circuits is disclosed. Foil stacks are bombarded with a high-energy electron beam of 25 to 250 MeV to produce a flux of soft X-rays of 500 eV to 3 keV. Methods of increasing the total X-ray power and making the cross section of the X-ray beam uniform are described. Methods of obtaining the desired X-ray-beam field size, optimum frequency spectrum and eliminating the neutron flux are all described. A method of obtaining a plurality of station operation is also described which makes the process more efficient and economical. The satisfying of these issues makes transition radiation an excellent moderate-priced X-ray source for lithography. 26 figures.

  10. Miniature x-ray source

    DOEpatents

    Trebes, James E.; Stone, Gary F.; Bell, Perry M.; Robinson, Ronald B.; Chornenky, Victor I.

    2002-01-01

    A miniature x-ray source capable of producing broad spectrum x-ray emission over a wide range of x-ray energies. The miniature x-ray source comprises a compact vacuum tube assembly containing a cathode, an anode, a high voltage feedthru for delivering high voltage to the anode, a getter for maintaining high vacuum, a connection for an 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 highly x-ray transparent and made, for example, from boron nitride. The compact size and potential for remote operation allows the x-ray source, for example, to be placed adjacent to a material sample undergoing analysis or in proximity to the region to be treated for medical applications.

  11. Miniature x-ray source

    DOEpatents

    Trebes, James E.; Bell, Perry M.; Robinson, Ronald B.

    2000-01-01

    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.

  12. X-ray burst sources

    NASA Technical Reports Server (NTRS)

    Lewin, W. H. G.

    1986-01-01

    There are about 100 bright X-ray sources in the Galaxy that are accretion-driven systems composed of a neutron star and a low mass companion that fills its critical Roche lobe. Many of these systems generate recurring X-ray bursts that are the result of thermonuclear flashes in the neutron star's surface layers, and are accompanied by a somewhat delayed optical burst due to X-ray heating of accretion disk. The Rapid Burster discovered in 1976 exhibits an interval between bursts that is strongly correlated with the energy in the preceding burst. There is no optical identification for this object.

  13. Focused X-ray source

    DOEpatents

    Piestrup, Melvin A.; Boyers, David G.; Pincus, Cary I.; Maccagno, Pierre

    1990-01-01

    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.

  14. Focused X-ray source

    DOEpatents

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

    1990-08-21

    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.

  15. Compact x-ray source and panel

    DOEpatents

    Sampayon, Stephen E.

    2008-02-12

    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.

  16. Tunable X-ray source

    DOEpatents

    Boyce, James R.

    2011-02-08

    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.

  17. Carbon nanotube based photocathodes

    NASA Astrophysics Data System (ADS)

    Hudanski, Ludovic; Minoux, Eric; Gangloff, Laurent; Teo, Kenneth B. K.; Schnell, Jean-Philippe; Xavier, Stephane; Robertson, John; Milne, William I.; Pribat, Didier; Legagneux, Pierre

    2008-03-01

    This paper describes a novel photocathode which is an array of vertically aligned multi-walled carbon nanotubes (MWCNTs), each MWCNT being associated with one p-i-n photodiode. Unlike conventional photocathodes, the functions of photon-electron conversion and subsequent electron emission are physically separated. Photon-electron conversion is achieved with p-i-n photodiodes and the electron emission occurs from the MWCNTs. The current modulation is highly efficient as it uses an optically controlled reconfiguration of the electric field at the MWCNT locations. Such devices are compatible with high frequency and very large bandwidth operation and could lead to their application in compact, light and efficient microwave amplifiers for satellite telecommunication. To demonstrate this new photocathode concept, we have fabricated the first carbon nanotube based photocathode using silicon p-i-n photodiodes and MWCNT bunches. Using a green laser, this photocathode delivers 0.5 mA with an internal quantum efficiency of 10% and an ION/IOFF ratio of 30.

  18. Late B Star X-Ray Sources

    NASA Astrophysics Data System (ADS)

    Walter, Frederick M.

    The most basic conclusion to be drawn from the EINSTEIN stellar X-ray observations was that all stars are X-ray sources - except the late-B and early- to mid-A stars. While this is still true in general, observations with the ROSAT X-ray observatory have shown that young late-B/early-A stars, those in and near regions of star formation, are often bright X-ray sources. It is not yet clear why (or, indeed, whether) young B-A stars are often X-ray sources. We request time on the IUE to observe a sample of these stars. We will compare the line profiles against B star models against archival spectra, looking for evidence of mass loss or mass inflows, as well as evidence of transition region gas. Detection of the latter will prove that the B stars are indeed X-ray sources.

  19. Modification of anisotropic plasma diffusion via auxiliary electrons emitted by a carbon nanotubes-based electron gun in an electron cyclotron resonance ion source.

    PubMed

    Malferrari, L; Odorici, F; Veronese, G P; Rizzoli, R; Mascali, D; Celona, L; Gammino, S; Castro, G; Miracoli, R; Serafino, T

    2012-02-01

    The diffusion mechanism in magnetized plasmas is a largely debated issue. A short circuit model was proposed by Simon, assuming fluxes of lost particles along the axial (electrons) and radial (ions) directions which can be compensated, to preserve the quasi-neutrality, by currents flowing throughout the conducting plasma chamber walls. We hereby propose a new method to modify Simon's currents via electrons injected by a carbon nanotubes-based electron gun. We found this improves the source performances, increasing the output current for several charge states. The method is especially sensitive to the pumping frequency. Output currents for given charge states, at different auxiliary electron currents, will be reported in the paper and the influence of the frequency tuning on the compensation mechanism will be discussed. PMID:22380190

  20. Models for galactic X-ray sources

    NASA Technical Reports Server (NTRS)

    Joss, P. C.

    1980-01-01

    Attention is given to those compact galactic X-ray sources whose X-ray luminosities are considerably in excess of the solar luminosity. It is pointed out that the key breakthrough in the development of an understanding of compact galactic X-ray sources was the discovery of X-ray pulsars with the UHURU satellite. There is now overwhelming evidence that these objects are neutron stars in close binary stellar systems. The X-ray pulsations are thought to be thermal emission from the magnetic polar caps of a neutron star that is accreting matter from a companion star and whose magnetic field is misaligned with its rotation axis. Among the compact galactic X-ray sources that are not X-ray pulsars, some still show direct evidence of binary membership, such as X-ray eclipses. There is evidence that the galactic-bulge sources are, in fact, close binary stellar systems. It is concluded, that the great majority of bright galactic X-ray sources, with only a tiny handful of exceptions (such as the Crab and Vela pulsars), are likely to be binaries.

  1. Detection of x ray sources in PROS

    NASA Technical Reports Server (NTRS)

    Deponte, J.; Primini, F. A.

    1992-01-01

    The problem of detecting discrete sources in x-ray images has much in common with the problem of automatic source detection at other wavelengths. In all cases, one searches for positive brightness enhancements exceeding a certain threshold, which appear consistent with what one expects for a point source, in the presence of a (possibly) spatially variable background. Multidimensional point spread functions (e.g., dependent on detector position and photon energy) are also common. At the same time, the problem in x-ray astronomy has some unique aspects. For example, for typical x-ray exposures in current or recent observatories, the number of available pixels far exceeds the number of actual x-ray events, so Poisson, rather than Gaussian statistics apply. Further, extended cosmic x-ray sources are common, and one often desires to detect point sources in the vicinity or even within bright, diffuse x-ray emission. Finally, support structures in x-ray detectors often cast sharp shadows in x-ray images making it necessary to detect sources in a region of rapidly varying exposure. We have developed a source detection package within the IRAF/PROS environment which attempts to deal with some of the problems of x-ray source detection. We have patterned our package after the successful Einstein Observatory x-ray source detection programs. However, we have attempted to improve the flexibility and accessibility of the functions and to provide a graphical front-end for the user. Our philosophy has been to use standard IRAF tasks whenever possible for image manipulation and to separate general functions from mission-specific ones. We will report on the current status of the package and discuss future developments, including simulation tasks, to allow the user to assess detection efficiency and source significance, tasks to determine source intensity, and alternative detection algorithms.

  2. Accelerator-driven X-ray Sources

    SciTech Connect

    Nguyen, Dinh Cong

    2015-11-09

    After an introduction which mentions x-ray tubes and storage rings and gives a brief review of special relativity, the subject is treated under the following topics and subtopics: synchrotron radiation (bending magnet radiation, wiggler radiation, undulator radiation, brightness and brilliance definition, synchrotron radiation facilities), x-ray free-electron lasers (linac-driven X-ray FEL, FEL interactions, self-amplified spontaneous emission (SASE), SASE self-seeding, fourth-generation light source facilities), and other X-ray sources (energy recovery linacs, Inverse Compton scattering, laser wakefield accelerator driven X-ray sources. In summary, accelerator-based light sources cover the entire electromagnetic spectrum. Synchrotron radiation (bending magnet, wiggler and undulator radiation) has unique properties that can be tailored to the users’ needs: bending magnet and wiggler radiation is broadband, undulator radiation has narrow spectral lines. X-ray FELs are the brightest coherent X-ray sources with high photon flux, femtosecond pulses, full transverse coherence, partial temporal coherence (SASE), and narrow spectral lines with seeding techniques. New developments in electron accelerators and radiation production can potentially lead to more compact sources of coherent X-rays.

  3. Globular cluster x-ray sources

    PubMed Central

    Pooley, David

    2010-01-01

    Globular clusters and x-ray astronomy have a long and fruitful history. Uhuru and OSO-7 revealed highly luminous (> 1036 ergs-1) x-ray sources in globular clusters, and Einstein and ROSAT revealed a larger population of low-luminosity (< 1033 ergs-1) x-ray sources. It was realized early on that the high-luminosity sources were low-mass x-ray binaries in outburst and that they were orders of magnitude more abundant per unit mass in globular clusters than in the rest of the galaxy. However, the low-luminosity sources proved difficult to classify. Many ideas were put forth—low-mass x-ray binaries in quiescence (qLMXBs), cataclysmic variables (CVs), active main-sequence binaries (ABs), and millisecond pulsars (MSPs)—but secure identifications were scarce. In ROSAT observations of 55 clusters, about 25 low-luminosity sources were found. Chandra has now observed over 80 Galactic globular clusters, and these observations have revealed over 1,500 x-ray sources. The superb angular resolution has allowed for many counterpart identifications, providing clues to the nature of this population. It is a heterogeneous mix of qLMXBs, CVs, ABs, and MSPs, and it has been shown that the qLMXBs and CVs are both, in part, overabundant like the luminous LMXBs. The number of x-ray sources in a cluster correlates very well with its encounter frequency. This points to dynamical formation scenarios for the x-ray sources and shows them to be excellent tracers of the complicated internal dynamics. The relation between the encounter frequency and the number of x-ray sources has been used to suggest that we have misunderstood the dynamical states of globular clusters. PMID:20404204

  4. X-Ray Emission from Compact Sources

    SciTech Connect

    Cominsky, L

    2004-03-23

    This paper presents a review of the physical parameters of neutron stars and black holes that have been derived from X-ray observations. I then explain how these physical parameters can be used to learn about the extreme conditions occurring in regions of strong gravity, and present some recent evidence for relativistic effects seen in these systems. A glossary of commonly used terms and a short tutorial on the names of X-ray sources are also included.

  5. X-ray source for mammography

    DOEpatents

    Logan, C.M.

    1994-12-20

    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.

  6. Spectra of cosmic x-ray sources

    SciTech Connect

    Holt, S.S.; Mccray, R.

    1982-02-01

    X-ray measurements provide the most direct probes of astrophysical environments with temperatures exceeding one million K. Progress in experimental research utilizing dispersive techniques (e.g., Bragg and grating spectroscopy) is considerably slower than that in areas utilizing photometric techniques, because of the relative inefficiency of the former for the weak X-ray signals from celestial sources. As a result, the term spectroscopy as applied to X-ray astronomy has traditionally satisfied a much less restrictive definition (in terms of resolving power) than it has in other wavebands. Until quite recently, resolving powers of order unity were perfectly respectable, and still provide (in most cases) the most useful spectroscopic data. In the broadest sense, X-ray photometric measurements are spectroscopic, insofar as they represent samples of the overall electromagnetic continua of celestial objects.

  7. X-ray source for mammography

    DOEpatents

    Logan, Clinton M.

    1994-01-01

    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.

  8. Spectra of cosmic X-ray sources

    NASA Technical Reports Server (NTRS)

    Holt, S. S.; Mccray, R.

    1982-01-01

    X-ray measurements provide the most direct probes of astrophysical environments with temperatures exceeding one million K. Progress in experimental research utilizing dispersive techniques (e.g., Bragg and grating spectroscopy) is considerably slower than that in areas utilizing photometric techniques, because of the relative inefficiency of the former for the weak X-ray signals from celestial sources. As a result, the term "spectroscopy" as applied to X-ray astronomy has traditionally satisfied a much less restrictive definition (in terms of resolving power) than it has in other wavebands. Until quite recently, resolving powers of order unity were perfectly respectable, and still provide (in most cases) the most useful spectroscopic data. In the broadest sense, X-ray photometric measurements are spectroscopic, insofar as they represent samples of the overall electromagnetic continua of celestial objects.

  9. Compton backscattered collmated X-ray source

    DOEpatents

    Ruth, Ronald D.; Huang, Zhirong

    2000-01-01

    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.

  10. Compton backscattered collimated x-ray source

    DOEpatents

    Ruth, R.D.; Huang, Z.

    1998-10-20

    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.

  11. Compton backscattered collimated x-ray source

    DOEpatents

    Ruth, Ronald D.; Huang, Zhirong

    1998-01-01

    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.

  12. High power distributed x-ray source

    NASA Astrophysics Data System (ADS)

    Frutschy, Kris; Neculaes, Bogdan; Inzinna, Lou; Caiafa, Antonio; Reynolds, Joe; Zou, Yun; Zhang, Xi; Gunturi, Satish; Cao, Yang; Waters, Bill; Wagner, Dave; De Man, Bruno; McDevitt, Dan; Roffers, Rick; Lounsberry, Brian; Pelc, Norbert J.

    2010-04-01

    This paper summarizes the development of a distributed x-ray source with up to 60kW demonstrated instantaneous power. Component integration and test results are shown for the dispenser cathode electron gun, fast switching controls, high voltage stand-off insulator, brazed anode, and vacuum system. The current multisource prototype has been operated for over 100 hours without failure, and additional testing is needed to discover the limiting component. Example focal spot measurements and x-ray radiographs are included. Lastly, future development opportunities are highlighted.

  13. Coherent Compton X-ray sources

    SciTech Connect

    Luccio, A.; Miceli, L.

    1993-12-31

    Coherent X-Rays can be produced by scattering of laser light by a beam of relativistic electrons, provided that the electron beam is density modulated or the scattering is done at, or near 90{degree}. Since the coherent scattering is proportional to N{sup 2}, where N is the number of electrons, and the incoherent scattering is proportional to N, also a modest degree of coherence can substantially increase the X-Ray yield. The theory of laser-electron beam scattering is reviewed and compared with the emission of radiation by an electron beam in an undulator. Examples of the practical implementation of an intense source of coherent X-Rays are discussed.

  14. X-ray sources in molecular clouds

    SciTech Connect

    Lepp, S.; McCray, R.

    1983-06-15

    Models are calculated for the structure and infrared line emission from a dense interstellar gas cloud containing a compact X-ray source. For constant gas pressure models, the resulting structure consists of nested spherical shells containing, respectively, coronal gas at T>10/sup 6/ K, an H II region with Tapprox.10/sup 4/ K, and H I region with Tapprox.8000 K, and finally an H/sub 2/ region with T<5000 K. Scaling laws are given for the locations of the transitions. Approximately 10% of the X-ray luminosity absorbed in the H/sub 2/ region is converted into infrared emission lines that may be observable. Line ratios are predicted.

  15. Colliding Wind Binary X-ray Sources

    NASA Astrophysics Data System (ADS)

    Corcoran, Michael F.; Hamaguchi, Kenji; Pollock, A. M. T.; Pittard, J. M.; Stevens, I. R.; Henley, D. B.; Moffat, A. F. J.; Marchenko, S.

    Very massive stars (≳ 20 M⊙) are rare but important components of galaxies. Products of core nucleosynthesis from these stars are distributed into the circumstellar environment via wind-driven mass loss. Explosive nucleosynthesis after core collapse further enriches the galactic medium. Clusters of such stars can produce galactic chimneys which can pierce the galactic disk and chemically enrich intergalactic space. Such processes are vitally important to the chemical evolution of the early Universe, when the stellar mass function was much more weighted to massive stars.Very massive stars are difficult to study, since they are formed in distant clusters which yield problems of sensitivity and source crowding. A relatively new tool for studying these systems is via high spatial, spectral and temporal resolution observations in the X-ray band. In this note we describe some recent progress in studying mechanisms by which very massive stars produce X-ray emission.

  16. Laser-based X-ray and electron source for X-ray fluorescence studies

    NASA Astrophysics Data System (ADS)

    Valle Brozas, F.; Crego, A.; Roso, L.; Peralta Conde, A.

    2016-08-01

    In this work, we present a modification to conventional X-rays fluorescence using electrons as excitation source and compare it with the traditional X-ray excitation for the study of pigments. For this purpose, we have constructed a laser-based source capable to produce X-rays as well as electrons. Because of the large penetration depth of X-rays, the collected fluorescence signal is a combination of several material layers of the artwork under study. However, electrons are stopped in the first layers, allowing a more superficial analysis. We show that the combination of both excitation sources can provide extremely valuable information about the structure of the artwork.

  17. Laser plasma x-ray source for ultrafast time-resolved x-ray absorption spectroscopy

    PubMed Central

    Miaja-Avila, L.; O'Neil, G. C.; Uhlig, J.; Cromer, C. L.; Dowell, M. L.; Jimenez, R.; Hoover, A. S.; Silverman, K. L.; Ullom, J. N.

    2015-01-01

    We describe a laser-driven x-ray plasma source designed for ultrafast x-ray absorption spectroscopy. The source is comprised of a 1 kHz, 20 W, femtosecond pulsed infrared laser and a water target. We present the x-ray spectra as a function of laser energy and pulse duration. Additionally, we investigate the plasma temperature and photon flux as we vary the laser energy. We obtain a 75 μm FWHM x-ray spot size, containing ∼106 photons/s, by focusing the produced x-rays with a polycapillary optic. Since the acquisition of x-ray absorption spectra requires the averaging of measurements from >107 laser pulses, we also present data on the source stability, including single pulse measurements of the x-ray yield and the x-ray spectral shape. In single pulse measurements, the x-ray flux has a measured standard deviation of 8%, where the laser pointing is the main cause of variability. Further, we show that the variability in x-ray spectral shape from single pulses is low, thus justifying the combining of x-rays obtained from different laser pulses into a single spectrum. Finally, we show a static x-ray absorption spectrum of a ferrioxalate solution as detected by a microcalorimeter array. Altogether, our results demonstrate that this water-jet based plasma source is a suitable candidate for laboratory-based time-resolved x-ray absorption spectroscopy experiments. PMID:26798792

  18. Laser plasma x-ray source for ultrafast time-resolved x-ray absorption spectroscopy

    DOE PAGESBeta

    Miaja-Avila, L.; O'Neil, G. C.; Uhlig, J.; Cromer, C. L.; Dowell, M. L.; Jimenez, R.; Hoover, A. S.; Silverman, K. L.; Ullom, J. N.

    2015-03-02

    We describe a laser-driven x-ray plasma source designed for ultrafast x-ray absorption spectroscopy. The source is comprised of a 1 kHz, 20 W, femtosecond pulsed infrared laser and a water target. We present the x-ray spectra as a function of laser energy and pulse duration. Additionally, we investigate the plasma temperature and photon flux as we vary the laser energy. We obtain a 75 μm FWHM x-ray spot size, containing ~106 photons/s, by focusing the produced x-rays with a polycapillary optic. Since the acquisition of x-ray absorption spectra requires the averaging of measurements from >107 laser pulses, we also presentmore » data on the source stability, including single pulse measurements of the x-ray yield and the x-ray spectral shape. In single pulse measurements, the x-ray flux has a measured standard deviation of 8%, where the laser pointing is the main cause of variability. Further, we show that the variability in x-ray spectral shape from single pulses is low, thus justifying the combining of x-rays obtained from different laser pulses into a single spectrum. Finally, we show a static x-ray absorption spectrum of a ferrioxalate solution as detected by a microcalorimeter array. Altogether, our results demonstrate that this water-jet based plasma source is a suitable candidate for laboratory-based time-resolved x-ray absorption spectroscopy experiments.« less

  19. Laser plasma x-ray source for ultrafast time-resolved x-ray absorption spectroscopy.

    PubMed

    Miaja-Avila, L; O'Neil, G C; Uhlig, J; Cromer, C L; Dowell, M L; Jimenez, R; Hoover, A S; Silverman, K L; Ullom, J N

    2015-03-01

    We describe a laser-driven x-ray plasma source designed for ultrafast x-ray absorption spectroscopy. The source is comprised of a 1 kHz, 20 W, femtosecond pulsed infrared laser and a water target. We present the x-ray spectra as a function of laser energy and pulse duration. Additionally, we investigate the plasma temperature and photon flux as we vary the laser energy. We obtain a 75 μm FWHM x-ray spot size, containing ∼10(6) photons/s, by focusing the produced x-rays with a polycapillary optic. Since the acquisition of x-ray absorption spectra requires the averaging of measurements from >10(7) laser pulses, we also present data on the source stability, including single pulse measurements of the x-ray yield and the x-ray spectral shape. In single pulse measurements, the x-ray flux has a measured standard deviation of 8%, where the laser pointing is the main cause of variability. Further, we show that the variability in x-ray spectral shape from single pulses is low, thus justifying the combining of x-rays obtained from different laser pulses into a single spectrum. Finally, we show a static x-ray absorption spectrum of a ferrioxalate solution as detected by a microcalorimeter array. Altogether, our results demonstrate that this water-jet based plasma source is a suitable candidate for laboratory-based time-resolved x-ray absorption spectroscopy experiments. PMID:26798792

  20. Laser plasma x-ray source for ultrafast time-resolved x-ray absorption spectroscopy

    SciTech Connect

    Miaja-Avila, L.; O'Neil, G. C.; Uhlig, J.; Cromer, C. L.; Dowell, M. L.; Jimenez, R.; Hoover, A. S.; Silverman, K. L.; Ullom, J. N.

    2015-03-02

    We describe a laser-driven x-ray plasma source designed for ultrafast x-ray absorption spectroscopy. The source is comprised of a 1 kHz, 20 W, femtosecond pulsed infrared laser and a water target. We present the x-ray spectra as a function of laser energy and pulse duration. Additionally, we investigate the plasma temperature and photon flux as we vary the laser energy. We obtain a 75 μm FWHM x-ray spot size, containing ~106 photons/s, by focusing the produced x-rays with a polycapillary optic. Since the acquisition of x-ray absorption spectra requires the averaging of measurements from >107 laser pulses, we also present data on the source stability, including single pulse measurements of the x-ray yield and the x-ray spectral shape. In single pulse measurements, the x-ray flux has a measured standard deviation of 8%, where the laser pointing is the main cause of variability. Further, we show that the variability in x-ray spectral shape from single pulses is low, thus justifying the combining of x-rays obtained from different laser pulses into a single spectrum. Finally, we show a static x-ray absorption spectrum of a ferrioxalate solution as detected by a microcalorimeter array. Altogether, our results demonstrate that this water-jet based plasma source is a suitable candidate for laboratory-based time-resolved x-ray absorption spectroscopy experiments.

  1. Plasma x-ray radiation source.

    PubMed

    Popkov, N F; Kargin, V I; Ryaslov, E A; Pikar', A S

    1995-01-01

    This paper gives the results of studies on a plasma x-ray source, which enables one to obtain a 2.5-krad radiation dose per pulse over an area of 100 cm2 in the quantum energy range from 20 to 500 keV. Pulse duration is 100 ns. Spectral radiation distributions from a diode under various operation conditions of a plasma are obtained. A Marx generator served as an initial energy source of 120 kJ with a discharge time of T/4 = 10-6 s. A short electromagnetic pulse (10-7 s) was shaped using plasma erosion opening switches. PMID:21307500

  2. A search for X-ray polarization in cosmic X-ray sources. [binary X-ray sources and supernovae remnants

    NASA Technical Reports Server (NTRS)

    Hughes, J. P.; Long, K. S.; Novick, R.

    1983-01-01

    Fifteen strong X-ray sources were observed by the X-ray polarimeters on board the OSO-8 satellite from 1975 to 1978. The final results of this search for X-ray polarization in cosmic sources are presented in the form of upper limits for the ten sources which are discussed elsewhere. These limits in all cases are consistent with a thermal origin for the X-ray emission.

  3. Advanced High Brilliance X-Ray Source

    NASA Technical Reports Server (NTRS)

    Gibson, Walter M.

    1998-01-01

    The possibility to dramatically increase the efficiency of laboratory based protein structure measurements through the use of polycapillary X-ray optics was investigated. This project initiated April 1, 1993 and concluded December 31, 1996 (including a no cost extension from June 31, 1996). This is a final report of the project. The basis for the project is the ability to collect X-rays from divergent electron bombardment laboratory X-ray sources and redirect them into quasiparallel or convergent (focused) beams. For example, a 0.1 radian (approx. 6 deg) portion of a divergent beam collected by a polycapillary collimator and transformed into a quasiparallel beam of 3 millradian (0.2 deg) could give a gain of 6(exp 2)/0.2(exp 2) x T for the intensity of a diffracted beam from a crystal with a 0.2 deg diffraction width. T is the transmission efficiency of the polycapillary diffraction optic, and for T=0.5, the gain would be 36/0.04 x O.5=45. In practice, the effective collection angle will depend on the source spot size, the input focal length of the optic (usually limited by the source spot-to-window distance on the x-ray tube) and the size of the crystal relative to the output diameter of the optic. The transmission efficiency, T, depends on the characteristics (fractional open area, surface roughness, shape and channel diameter) of the polycapillary optic and is typically in the range 0.2-0.4. These effects could substantially reduce the expected efficiency gain. During the course of this study, the possibility to use a weakly focused beam (0.5 deg convergence) was suggested which could give an additional 10-20 X efficiency gain for small samples . Weakly focused beams from double focusing mirrors are frequently used for macromolecular crystallography studies. Furthermore the crystals are typically oscillated by as much as 2 deg during each X-ray exposure in order to increase the reciprocal space (number of crystal planes) sampled and use of a slightly convergent

  4. The Integrated X-Ray Spectrum of Galactic Populations of Luminous Supersoft X-Ray Sources

    NASA Technical Reports Server (NTRS)

    DiStefano, R.; Becker, C. M.; Fabbiano, G.

    1996-01-01

    We compute the composite X-ray spectrum of a population of unresolved SSS's in a spiral galaxy such as our own or M31. The sources are meant to represent the total underlying population corresponding to all sources which have bolometric luminosities in the range of 10(exp 37) - 10(exp 38) ergs/s and kT on the order of tens of eV. These include close-binary supersoft sources, symbiotic novae, and planetary nebulae, for example. In order to determine whether the associated X-ray signal would be detectable, we also 'seed' the galaxy with other types of X-ray sources, specifically low-mass X-ray binaries (LMXB's) and high-mass X-ray binaries (HMXB's). We find that the total spectrum due to SSS's, LMXB's, and HMXB's exhibits a soft peak which owes its presence to the SSS population. Preliminary indications are that this soft peak may be observable.

  5. Probing the influence of the center atom coordination structure in iron phthalocyanine multi-walled carbon nanotube-based oxygen reduction reaction catalysts by X-ray absorption fine structure spectroscopy

    NASA Astrophysics Data System (ADS)

    Peng, Yingxiang; Li, Zhipan; Xia, Dingguo; Zheng, Lirong; Liao, Yi; Li, Kai; Zuo, Xia

    2015-09-01

    Three different pentacoordinate iron phthalocyanine (FePc) electrocatalysts with an axial ligand (pyridyl group, Py) anchored to multi-walled carbon nanotubes (MWCNTs) are prepared by a microwave method as high performance composite electrocatalysts (FePc-Py/MWCNTs) for the oxygen reduction reaction (ORR). For comparison, tetracoordinate FePc electrocatalysts without an axial ligand anchored to MWCNTs (FePc/MWCNTs) are assembled in the same way. Ultraviolet-visible spectrophotometry (UV-Vis), Raman spectroscopy (RS), and high-resolution transmission electron microscopy (HRTEM) are used to characterize the obtained electrocatalysts. The electrocatalytic activity of the samples is measured by linear sweep voltammetry (LSV), and the onset potential of all of the FePc-Py/MWCNTs electrocatalysts is found to be more positive than that of their FePc/MWCNTs counterparts. X-ray photoelectron spectroscopy (XPS) and X-ray absorption fine structure (XAFS) spectroscopy are employed to elucidate the relationship between molecular structure and electrocatalytic activity. XPS indicates that higher concentrations of Fe3+ and pyridine-type nitrogen play critical roles in determining the electrocatalytic ORR activity of the samples. XAFS spectroscopy reveals that the FePc-Py/MWCNTs electrocatalysts have a coordination geometry around Fe that is closer to the square pyramidal structure, a higher concentration of Fe3+, and a smaller phthalocyanine ring radius compared with those of FePc/MWCNTs.

  6. Femtosecond laser-electron x-ray source

    DOEpatents

    Hartemann, Frederic V.; Baldis, Hector A.; Barty, Chris P.; Gibson, David J.; Rupp, Bernhard

    2004-04-20

    A femtosecond laser-electron X-ray source. A high-brightness relativistic electron injector produces an electron beam pulse train. A system accelerates the electron beam pulse train. The femtosecond laser-electron X-ray source includes a high intra-cavity power, mode-locked laser and an x-ray optics system.

  7. Ultra Luminous X-ray Sources

    NASA Astrophysics Data System (ADS)

    Webb, N. A.; Godet, O.

    2015-12-01

    Ultra Luminous X-ray sources (ULXs) are X-ray bright objects that are not coincident with the central nucleus of the host galaxy and which have luminosities that exceed the Eddington limit for a stellar mass black hole, typically L > 3 × 10^{39} erg s^{-1} for a black hole of 20 M_⊙. The nature of these objects is still unclear. However, it is possible that these sources do not form a single class of objects. Many ULXs may house stellar mass black holes accreting at super-Eddington rates, even if the physical mechanism for such high accretion rates is still not understood. Some ULXs may contain intermediate mass black holes (˜1 × 10^{2} - ˜1 × 10^{5} M_⊙). These elusive black holes are thought to be the building blocks of the more massive supermassive black holes, observed at the centre of many galaxies. Other ULXs may not be accreting black holes at all. Recent evidence for the different types of ULXs is presented in this paper.

  8. Nanomaterial-based x-ray sources

    NASA Astrophysics Data System (ADS)

    Cole, Matthew T.; Parmee, R. J.; Milne, William I.

    2016-02-01

    Following the recent global excitement and investment in the emerging, and rapidly growing, classes of one and two-dimensional nanomaterials, we here present a perspective on one of the viable applications of such materials: field electron emission based x-ray sources. These devices, which have a notable history in medicine, security, industry and research, to date have almost exclusively incorporated thermionic electron sources. Since the middle of the last century, field emission based cathodes were demonstrated, but it is only recently that they have become practicable. We outline some of the technological achievements of the past two decades, and describe a number of the seminal contributions. We explore the foremost market hurdles hindering their roll-out and broader industrial adoption and summarise the recent progress in miniaturised, pulsed and multi-source devices.

  9. Nanomaterial-based x-ray sources.

    PubMed

    Cole, Matthew T; Parmee, R J; Milne, William I

    2016-02-26

    Following the recent global excitement and investment in the emerging, and rapidly growing, classes of one and two-dimensional nanomaterials, we here present a perspective on one of the viable applications of such materials: field electron emission based x-ray sources. These devices, which have a notable history in medicine, security, industry and research, to date have almost exclusively incorporated thermionic electron sources. Since the middle of the last century, field emission based cathodes were demonstrated, but it is only recently that they have become practicable. We outline some of the technological achievements of the past two decades, and describe a number of the seminal contributions. We explore the foremost market hurdles hindering their roll-out and broader industrial adoption and summarise the recent progress in miniaturised, pulsed and multi-source devices. PMID:26807781

  10. Compact X-ray sources: X-rays from self-reflection

    NASA Astrophysics Data System (ADS)

    Mangles, Stuart P. D.

    2012-05-01

    Laser-based particle acceleration offers a way to reduce the size of hard-X-ray sources. Scientists have now developed a simple scheme that produces a bright flash of hard X-rays by using a single laser pulse both to generate and to scatter an electron beam.

  11. X-ray bursters and the X-ray sources of the galactic bulge

    NASA Technical Reports Server (NTRS)

    Lewin, W. H. G.; Joss, P. C.

    1980-01-01

    Type 1 X-ray bursts, optical, infrared, and radio properties of the galactic bulge sources, are discussed. It was proven that these burst sources are neutron stars in low mass, close binary stellar systems. Several burst sources are found in globular clusters with high central densities. Optical type 1 X-ray bursts were observed from three sources. Type 2 X-ray bursts, observed from the Rapid Burster, are due to an accretion instability which converts gravitational potential energy into heat and radiation, which makes them of a fundamentally different nature from Type 1 bursts.

  12. X-Ray Scattering Applications Using Pulsed X-Ray Sources

    SciTech Connect

    Larson, B.C.

    1999-05-23

    Pulsed x-ray sources have been used in transient structural phenomena investigations for over fifty years; however, until the advent of synchrotrons sources and the development of table-top picosecond lasers, general access to ligh temporal resolution x-ray diffraction was relatively limited. Advances in diffraction techniques, sample excitation schemes, and detector systems, in addition to IncEased access to pulsed sources, have ld tO what is now a diverse and growing array of pulsed-source measurement applications. A survey of time-resolved investigations using pulsed x-ray sources is presented and research opportunities using both present and planned pulsed x-ray sources are discussed.

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

    SciTech Connect

    Morihana, Kumiko; Tsujimoto, Masahiro; Ebisawa, Ken; Yoshida, Tessei

    2013-03-20

    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.

  14. Balloon observations of hard X-rays from some galactic X-ray sources

    NASA Technical Reports Server (NTRS)

    Damle, S. V.; Kunte, P. K.; Naranan, S.; Sreekantan, B. V.; Leahy, D. A.; Venkatesan, D.

    1985-01-01

    An X-ray telescope consisting of 400 cm phoswich detectors (NaI(T1)/CsI(Na)) was flown from Hyderabad (India) on 18 December 1984. The field of view was 5 deg x 5 deg FWHM. In a 10 hour float at 4 MB several galactic X-ray sources were tracked by the telescope using an on-board microprocessor. Fluxes and spectra in 18-120 keV X-rays for SCO X-1, GX 1+4, Gx 5-1, GX 17+2, SCT X-1, CYC X-1 an CYG X-3 will be presented.

  15. Line-Source Based X-Ray Tomography

    PubMed Central

    Bharkhada, Deepak; Yu, Hengyong; Liu, Hong; Plemmons, Robert; Wang, Ge

    2009-01-01

    Current computed tomography (CT) scanners, including micro-CT scanners, utilize a point x-ray source. As we target higher and higher spatial resolutions, the reduced x-ray focal spot size limits the temporal and contrast resolutions achievable. To overcome this limitation, in this paper we propose to use a line-shaped x-ray source so that many more photons can be generated, given a data acquisition interval. In reference to the simultaneous algebraic reconstruction technique (SART) algorithm for image reconstruction from projection data generated by an x-ray point source, here we develop a generalized SART algorithm for image reconstruction from projection data generated by an x-ray line source. Our numerical simulation results demonstrate the feasibility of our novel line-source based x-ray CT approach and the proposed generalized SART algorithm. PMID:19436708

  16. Mobile, scanning x-ray source for mine detection using backscattered x-rays

    SciTech Connect

    Shope, S.; Lockwood, G.; Bishop, L.; Selph, M.; Jojola, J.; Wavrik, R.; Turman, B.; Wehlburg, J.

    1997-04-01

    A continuously operating, scanning x-ray machine is being developed for landmine detection using backscattered x-rays. The source operates at 130 kV and 650 mA. The x-rays are formed by electrons striking a high Z target. Target shape is an approximate 5 cm wide by 210 cm long racetrack. The electron beam is scanned across this target with electromagnets. There are 105, 1-cm by 1-cm collimators in each leg of the racetrack for a total of 210 collimators. The source is moved in the forward direction(the direction perpendicular to the 210-cm dimension) at 3 mi/h. The forward velocity and collimator spacing are such that a grid of collimated x-rays are projected at normal incidence to the soil. The spacing between the collimators and the ground results in a 2-cm by 2-cm x-ray pixel on the ground. A unique detector arrangement of collimated and uncollimated detectors allows surface features to be recognized and removed, leaving an image of a buried landmine. Another detector monitors the uncollimated x-ray output and is used to normalize the source output. The mine detector is being prepared for an Advanced Technology Demonstration (ATD). The ATD is scheduled for midyear of 1998. The results of the source performance in pre ATD tests will be presented.

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

    DOEpatents

    Bitter, Manfred L.; Fraenkel, Ben; Gorman, James L.; Hill, Kenneth W.; Roquemore, A. Lane; Stodiek, Wolfgang; von Goeler, Schweickhard E.

    2001-01-01

    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.

  18. All-laser-driven Thomson X-ray sources

    NASA Astrophysics Data System (ADS)

    Umstadter, Donald P.

    2015-10-01

    We discuss the development of a new generation of accelerator-based hard X-ray sources driven exclusively by laser light. High-intensity laser pulses serve the dual roles: first, accelerating electrons by laser-driven plasma wakefields, and second, generating X-rays by inverse Compton scattering. Such all-laser-driven X-rays have recently been demonstrated to be energetic, tunable, relatively narrow in bandwidth, short pulsed and well collimated. Such characteristics, especially from a compact source, are highly advantageous for numerous advanced X-ray applications - in metrology, biomedicine, materials, ultrafast phenomena, radiology and fundamental physics.

  19. Multilayers for next generation x-ray sources

    SciTech Connect

    Bajt, S; Chapman, H N; Spiller, E; Hau-Riege, S; Alameda, J; Nelson, A J; Walton, C C; Kjornrattanawanich, B; Aquila, A; Dollar, F; Gullikson, E; Tarrio, C

    2007-05-04

    Multilayers are artificially layered structures that can be used to create optics and optical elements for a broad range of x-ray wavelengths, or can be optimized for other applications. The development of next generation x-ray sources (synchrotrons and x-ray free electron lasers) requires advances in x-ray optics. Newly developed multilayer-based mirrors and optical elements enabled efficient band-pass filtering, focusing and time resolved measurements in recent FLASH (Free Electron LASer in Hamburg) experiments. These experiments are providing invaluable feedback on the response of the multilayer structures to high intensity, short pulsed x-ray sources. This information is crucial to design optics for future x-ray free electron lasers and to benchmark computer codes that simulate damage processes.

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

    PubMed

    Du, Yingchao; Yan, Lixin; Hua, Jianfei; Du, Qiang; Zhang, Zhen; Li, Renkai; Qian, Houjun; Huang, Wenhui; Chen, Huaibi; Tang, Chuanxiang

    2013-05-01

    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 × 10(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. PMID:23742539

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

    SciTech Connect

    Du Yingchao; Yan Lixin; Hua Jianfei; Du Qiang; Zhang Zhen; Li Renkai; Qian Houjun; Huang Wenhui; Chen Huaibi; Tang Chuanxiang

    2013-05-15

    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.

  2. Long-term X-ray variability of ultraluminous X-ray sources

    NASA Astrophysics Data System (ADS)

    Lin, Lupin Chun-Che; Hu, Chin-Ping; Kong, Albert K. H.; Yen, David Chien-Chang; Takata, Jumpei; Chou, Yi

    2015-12-01

    Long-term X-ray modulations on time-scales from tens to hundreds of days have been widely studied for X-ray binaries located in the Milky Way and the Magellanic Clouds. For other nearby galaxies, only the most luminous X-ray sources can be monitored with dedicated observations. We here present the first systematic study of long-term X-ray variability of four ultraluminous X-ray sources (ESO 243-49 HLX-1, Holmberg IX X-1, M81 X-6, and NGC 5408 X-1) monitored with Swift. By using various dynamic techniques to analyse their light curves, we find several interesting low-frequency quasi-periodicities. Although the periodic signals may not represent any stable orbital modulations, these detections reveal that such long-term regular patterns may be related to superorbital periods and structure of the accretion discs. In particular, we show that the outburst recurrence time of ESO 243-49 HLX-1 varies over time and suggest that it may not be the orbital period. Instead, it may be due to some kinds of precession, and the true binary period is expected to be much shorter.

  3. X-ray framing camera for pulsed, high current, electron beam x-ray sources

    NASA Astrophysics Data System (ADS)

    Failor, B. H.; Rodriguez, J. C.; Riordan, J. C.; Lojewski, D. Y.

    2007-07-01

    High power x-ray sources built for nuclear weapons effects testing are evolving toward larger overall diameters and smaller anode cathode gaps. We describe a framing camera developed to measure the time-evolution of these 20-50 ns pulsed x-ray sources produced by currents in the 1.5-2.5 MA range and endpoint voltages between 0.2 and 1.5 MV. The camera has up to 4 frames with 5 ns gate widths; the frames are separated by 5 ns. The image data are recorded electronically with a gated intensified CCD camera and the data are available immediately following a shot. A fast plastic scintillator (2.1 ns decay time) converts the x-rays to visible light and, for high sensitivity, a fiber optic imaging bundle carries the light to the CCD input. Examples of image data are shown.

  4. Faint X-ray source counts and the origin of the X-ray background

    NASA Technical Reports Server (NTRS)

    Hamilton, T. T.; Helfand, D. J.; Wu, X.

    1991-01-01

    A thorough reanalysis of the Einstein Observatory Deep Survey data is presented in order to determine the contribution of detected, discrete sources of X-ray emission to the cosmic X-ray background. Substantial discrepancies with previously published work on this problem are found. A detailed discussion of data editing and source algorithms buttresses a claim of having constructed a complete, flux-limited sample of the faintest sources detectable with the Einstein imaging proportional counter, the most sensitive X-ray instrument yet flown. A total of 33 sources is found in a survey region of about 3.3 sq deg down to a minimum flux threshold of 4 x 10 to the 14th ergs/sq cm/s in the 0.3-3.5 keV band. Roughly 30 percent of the objects are foreground stars, leading to an extragalactic source surface density of 70,000/sr at this threshold. The integrated contribution from discrete sources to the number of cosmic X-ray background photons measured in this same band with the same instrument is 12 percent + or - 3 percent, substantially below previous estimates. Implications of these results for the origin of the background are discussed.

  5. Preliminary designs for X-ray source modifications for the Marshall Space Flight Center's X-ray calibration facility

    NASA Technical Reports Server (NTRS)

    Croft, W. L.

    1986-01-01

    The objective of this investigation is to develop preliminary designs for modifications to the X-ray source of the MSFC X-Ray Calibration Facility. Recommendations are made regarding: (1) the production of an unpolarized X-ray beam, (2) modification of the source to provide characteristic X-rays with energies up to 40 keV, and (3) addition of the capability to calibrate instruments in the extreme ultraviolet wavelength region.

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

    SciTech Connect

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

    1999-05-01

    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.

  7. X-Ray Sources in the Dwarf Spheroidal Galaxy Draco

    NASA Astrophysics Data System (ADS)

    Sonbas, E.; Rangelov, B.; Kargaltsev, O.; Dhuga, K. S.; Hare, J.; Volkov, I.

    2016-04-01

    We present the spectral analysis of an 87 ks XMM-Newton observation of Draco, a nearby dwarf spheroidal galaxy. Of the approximately 35 robust X-ray source detections, we focus our attention on the brightest of these sources, for which we report X-ray and multiwavelength parameters. While most of the sources exhibit properties consistent with active galactic nuclei, few of them possess the characteristics of low-mass X-ray binaries (LMXBs) and cataclysmic variable (CVs). Our analysis places constraints on the population of X-ray sources with LX > 3 × 1033 erg s‑1 in Draco, suggesting that there are no actively accreting black hole and neutron star binaries. However, we find four sources that could be quiescent state LMXBs/CVs associated with Draco. We also place constraints on the central black hole luminosity and on a dark matter decay signal around 3.5 keV.

  8. Miniaturized High-Speed Modulated X-Ray Source

    NASA Technical Reports Server (NTRS)

    Gendreau, Keith C. (Inventor); Arzoumanian, Zaven (Inventor); Kenyon, Steven J. (Inventor); Spartana, Nick Salvatore (Inventor)

    2015-01-01

    A miniaturized high-speed modulated X-ray source (MXS) device and a method for rapidly and arbitrarily varying with time the output X-ray photon intensities and energies. The MXS device includes an ultraviolet emitter that emits ultraviolet light, a photocathode operably coupled to the ultraviolet light-emitting diode that emits electrons, an electron multiplier operably coupled to the photocathode that multiplies incident electrons, and an anode operably coupled to the electron multiplier that is configured to produce X-rays. The method for modulating MXS includes modulating an intensity of an ultraviolet emitter to emit ultraviolet light, generating electrons in response to the ultraviolet light, multiplying the electrons to become more electrons, and producing X-rays by an anode that includes a target material configured to produce X-rays in response to impact of the more electrons.

  9. Generation of High Brightness X-rays with the PLEIADES Thomson X-ray Source

    SciTech Connect

    Brown, W J; Anderson, S G; Barty, C P J; Crane, J K; Cross, R R; Fittinghoff, D N; Hartemann, F V; Kuba, J; LeSage, G P; Slaughter, D R; Springer, P T; Tremaine, A M; Rosenzweig, J B; Gibson, D J

    2003-05-28

    The use of short laser pulses to generate high peak intensity, ultra-short x-ray pulses enables exciting new experimental capabilities, such as femtosecond pump-probe experiments used to temporally resolve material structural dynamics on atomic time scales. PLEIADES (Picosecond Laser Electron InterAction for Dynamic Evaluation of Structures) is a next generation Thomson scattering x-ray source being developed at Lawrence Livermore National Laboratory (LLNL). Ultra-fast picosecond x-rays (10-200 keV) are generated by colliding an energetic electron beam (20-100 MeV) with a high intensity, sub-ps, 800 nm laser pulse. The peak brightness of the source is expected to exceed 10{sup 20} photons/s/0.1% bandwidth/mm2/mrad2. Simulations of the electron beam production, transport, and final focus are presented. Electron beam measurements, including emittance and final focus spot size are also presented and compared to simulation results. Measurements of x-ray production are also reported and compared to theoretical calculations.

  10. Laser-Produced Coherent X-Ray Sources

    SciTech Connect

    Donald Umstadter

    2007-01-31

    We study the generation of x-rays from the interaction of relativistic electrons with ultra-intense laser pulse either directly or via laser generated ion channels. The laser pulse acts as the accelerator and wiggler leading to an all-optical synchrotron-like x-ray source. The mm sized accelerator and micron-sized wiggler leads to a compact source of high brightness, ultrafast x-rays with applications in relativistic nonlinear optics, ultrafast chemistry, biology, inner-shell electronic processes and phase transitions.

  11. Transition radiation as a source of cosmic X-rays.

    NASA Technical Reports Server (NTRS)

    Ramaty, R.; Bleach, R. D.

    1972-01-01

    It is shown that transition radiation generated during the passage of relativistic charged particles through interstellar grains can be an important source of cosmic X-rays. In order to account for recent X-ray observations below 300 eV by transition radiation, an energy density in interstellar space of about 10 eV per cu cm in 10 MeV electrons is required. This seems to rule out transition radiation as an important source of diffuse cosmic X-rays in any energy region.

  12. Exotic X-ray Sources from Intermediate Energy Electron Beams

    SciTech Connect

    Chouffani, K.; Wells, D.; Harmon, F.; Jones, J.L.; Lancaster, G.

    2003-08-26

    High intensity x-ray beams are used in a wide variety of applications in solid-state physics, medicine, biology and material sciences. Synchrotron radiation (SR) is currently the primary, high-quality x-ray source that satisfies both brilliance and tunability. The high cost, large size and low x-ray energies of SR facilities, however, are serious limitations. Alternatively, 'novel' x-ray sources are now possible due to new small linear accelerator (LINAC) technology, such as improved beam emittance, low background, sub-Picosecond beam pulses, high beam stability and higher repetition rate. These sources all stem from processes that produce Radiation from relativistic Electron beams in (crystalline) Periodic Structures (REPS), or the periodic 'structure' of laser light. REPS x-ray sources are serious candidates for bright, compact, portable, monochromatic, and tunable x-ray sources with varying degrees of polarization and coherence. Despite the discovery and early research into these sources over the past 25 years, these sources are still in their infancy. Experimental and theoretical research are still urgently needed to answer fundamental questions about the practical and ultimate limits of their brightness, mono-chromaticity etc. We present experimental results and theoretical comparisons for three exotic REPS sources. These are Laser-Compton Scattering (LCS), Channeling Radiation (CR) and Parametric X-Radiation (PXR)

  13. Quasisoft X-ray Sources: their physical natures revealed

    NASA Astrophysics Data System (ADS)

    Di Stefano, Rosanne; Primini, Francis A.; Guo, Jincheng; Liu, Jifeng

    2016-04-01

    Quasisoft X-ray sources (QSSs) have been the Mona Lisa of X-ray sources. They have remained enigmatic, even though we have known of their existence and basic properties for more than a decade. QSSs have X-ray luminosities greater than 10^{36} erg/s, but emit few or no photons above 2 keV. They were discovered in external galaxies during searches for softer sources, supersoft X-ray sources (SSSs). Every external galaxy contains QSSs, but it has been challenging to find any in the Milky Way and the Magellanic Clouds. Recent work, however, reveals that a significant fraction of QSSs may be black holes. We review what is known about QSSs to date, because this obscure class of objects may at last to be ready for "prime time'', capable of identifying BHs in a wide range of Galactic environments.

  14. Self-cleaning rotating anode x-ray source

    DOEpatents

    Paulikas, A.P.

    1987-06-02

    A self-cleaning rotating anode x-ray source comprising and evacuable housing, a rotatable cylindrical anode within the housing, a source of electrons within the housing which electrons are caused to impinge upon the anode to produce x-rays, and means for ionizing residual particles within the housing and accelerating such ions so as to impinge upon the anode to sputter impurities from the surface thereof. 2 figs.

  15. Self-cleaning rotating anode X-ray source

    DOEpatents

    Paulikas, Arvydas P.

    1989-01-01

    A self-cleaning rotating anode x-ray source comprising an evacuable housing, a rotatable cylindrical anode within the housing, a source of electrons within the housing which electrons are caused to impinge upon the anode to produce x-rays, and means for ionizing residual particles within the housing and accelerating such ions so as to impinge upon the anode to sputter impurities from the surface thereof.

  16. New Directions in X-Ray Light Sources

    ScienceCinema

    Falcone, Roger

    2010-01-08

    July 15, 2008 Berkeley Lab lecture: Molecular movies of chemical reactions and material phase transformations need a strobe of x-rays, the penetrating light that reveals how atoms and molecules assemble in chemical and biological systems and complex materials. Roger Falcone, Director of the Advanced Light Source,will discuss a new generation of x ray sources that will enable a new science of atomic dynamics on ultrafast timescales.

  17. New Directions in X-Ray Light Sources

    SciTech Connect

    Falcone, Roger

    2008-07-18

    July 15, 2008 Berkeley Lab lecture: Molecular movies of chemical reactions and material phase transformations need a strobe of x-rays, the penetrating light that reveals how atoms and molecules assemble in chemical and biological systems and complex materials. Roger Falcone, Director of the Advanced Light Source,will discuss a new generation of x ray sources that will enable a new science of atomic dynamics on ultrafast timescales.

  18. ANS hard X-ray experiment development program. [emission from X-ray sources

    NASA Technical Reports Server (NTRS)

    Parsignault, D.; Gursky, H.; Frank, R.; Kubierschky, K.; Austin, G.; Paganetti, R.; Bawdekar, V.

    1974-01-01

    The hard X-ray (HXX) experiment is one of three experiments included in the Dutch Astronomical Netherlands Satellite, which was launched into orbit on 30 August 1974. The overall objective of the HXX experiment is the detailed study of the emission from known X-ray sources over the energy range 1.5-30keV. The instrument is capable of the following measurements: (1) spectral content over the full energy range with an energy resolution of approximately 20% and time resolution down to 4 seconds; (2) source time variability down to 4 milliseconds; (3) silicon emission lines at 1.86 and 2.00keV; (4) source location to a limit of one arc minute in ecliptic latitude; and (5) spatial structure with angular resolution of the arc minutes. Scientific aspects of experiment, engineering design and implementation of the experiment, and program history are included.

  19. Miniaturized, High-Speed, Modulated X-Ray Source

    NASA Technical Reports Server (NTRS)

    Gendreau, Keith; Arzoumanian, Zaven; Kenyon, Steve; Spartana, Nick

    2013-01-01

    A low-cost, miniature x-ray source has been developed that can be modulated in intensity from completely off to full intensity on nanosecond timescales. This modulated x-ray source (MXS) has no filaments and is extremely rugged. The energy level of the MXS is adjustable from 0 to more than 100 keV. It can be used as the core of many new devices, providing the first practical, arbitrarily time-variable source of x-rays. The high-speed switching capability and miniature size make possible many new technologies including x-ray-based communication, compact time-resolved x-ray diffraction, novel x-ray fluorescence instruments, and low- and precise-dose medical x-rays. To make x-rays, the usual method is to accelerate electrons into a target material held at a high potential. When the electrons stop in the target, x-rays are produced with a spectrum that is a function of the target material and the energy to which the electrons are accelerated. Most commonly, the electrons come from a hot filament. In the MXS, the electrons start off as optically driven photoelectrons. The modulation of the x-rays is then tied to the modulation of the light that drives the photoelectron source. Much of the recent development has consisted of creating a photoelectrically-driven electron source that is robust, low in cost, and offers high intensity. For robustness, metal photocathodes were adopted, including aluminum and magnesium. Ultraviolet light from 255- to 350-nm LEDs (light emitting diodes) stimulated the photoemissions from these photocathodes with an efficiency that is maximized at the low-wavelength end (255 nm) to a value of roughly 10(exp -4). The MXS units now have much higher brightness, are much smaller, and are made using a number of commercially available components, making them extremely inexpensive. In the latest MXS design, UV efficiency is addressed by using a high-gain electron multiplier. The photocathode is vapor-deposited onto the input cone of a Burle Magnum

  20. The SWIRE/Chandra Survey: The X-ray Sources

    NASA Astrophysics Data System (ADS)

    Wilkes, Belinda J.; Kilgard, Roy; Kim, Dong-Woo; Kim, Minsun; Polletta, Mari; Lonsdale, Carol; Smith, Harding E.; Surace, Jason; Owen, Frazer N.; Franceschini, A.; Siana, Brian; Shupe, David

    2009-12-01

    We report a moderate-depth (70 ks), contiguous 0.7 deg2 Chandra survey in the Lockman Hole Field of the Spitzer/SWIRE Legacy Survey coincident with a completed, ultra-deep VLA survey with deep optical and near-infrared imaging in-hand. The primary motivation is to distinguish starburst galaxies and active galactic nuclei (AGNs), including the significant, highly obscured (log N H > 23) subset. Chandra has detected 775 X-ray sources to a limiting broadband (0.3-8 keV) flux ~4 × 10-16 erg cm-2 s-1. We present the X-ray catalog, fluxes, hardness ratios, and multi-wavelength fluxes. The log N versus log S agrees with those of previous surveys covering similar flux ranges. The Chandra and Spitzer flux limits are well matched: 771 (99%) of the X-ray sources have infrared (IR) or optical counterparts, and 333 have MIPS 24 μm detections. There are four optical-only X-ray sources and four with no visible optical/IR counterpart. The very deep (~2.7 μJy rms) VLA data yield 251 (>4σ) radio counterparts, 44% of the X-ray sources in the field. We confirm that the tendency for lower X-ray flux sources to be harder is primarily due to absorption. As expected, there is no correlation between observed IR and X-ray fluxes. Optically bright, type 1, and red AGNs lie in distinct regions of the IR versus X-ray flux plots, demonstrating the wide range of spectral energy distributions in this sample and providing the potential for classification/source selection. Many optically bright sources, which lie outside the AGN region in the optical versus X-ray plots (fr /fx >10), lie inside the region predicted for red AGNs in IR versus X-ray plots, consistent with the presence of an active nucleus. More than 40% of the X-ray sources in the VLA field are radio-loud using the classical definition, RL . The majority of these are red and relatively faint in the optical so that the use of RL to select those AGNs with the strongest radio emission becomes questionable. Using the 24 μm to radio

  1. Bright X-Ray Sources in M31 Globular Clusters

    NASA Astrophysics Data System (ADS)

    Di Stefano, R.; Kong, A. K. H.; Garcia, M. R.; Barmby, P.; Greiner, J.; Murray, S. S.; Primini, F. A.

    2002-05-01

    We have conducted Chandra observations of ~2560 arcmin2 (~131 kpc2) of M31 and find that the most luminous X-ray sources in most of our fields are in globular clusters. Of the 28 globular cluster X-ray sources in our fields, 15 are newly discovered. Approximately one-third of all the sources have LX([0.5-7] keV)>1037 ergs s-1, and approximately one-tenth of all the sources have LX([0.5-7] keV) close to or above 1038 ergs s-1. The most luminous source, in the globular cluster Bo 375, is consistently observed to have LX greater than 2×1038 ergs s-1. (1) We present data on the spectra and/or light curves of the five most luminous M31 globular cluster sources. (2) We explore possible explanations for the high X-ray luminosities of the brightest sources. These include that the X-ray sources may be composites, the radiation we receive may be beamed, metallicity effects could be at work, or the sources may be accreting black holes. We weigh each of these possibilities against the data. In addition, we introduce a neutron star model in which mass transfer proceeds on the thermal timescale of the donor star. Our model can produce luminosities of several times 1038 ergs s-1 and leads to a set of well-defined predictions. (3) We compute the X-ray luminosity function and the distribution of counts in wavebands that span the range of energies to which Chandra is sensitive. We find the peak X-ray luminosity is higher and that systems with LX>1037 ergs s-1 constitute a larger fraction of all GC sources than in our Galaxy. (4) We study the possible reasons for this difference between M31 and Galactic globular cluster X-ray sources and identify three promising explanations.

  2. Classifying the Zoo of Ultraluminous X-ray Sources

    NASA Astrophysics Data System (ADS)

    Soria, Roberto; Cropper, Mark; Motch, Christian

    2005-06-01

    Ultraluminous X-ray sources (ULXs) are likely to include different physical types of objects. We discuss some possible subclasses, reviewing the properties of a sample of ULXs recently observed by Chandra and XMM-Newton. Sources with an isotropic X-ray luminosity up to a few times 1039 erg s-1 are consistent with ``normal'' stellar-mass X-ray binaries (mostly high-mass X-ray binaries in star-forming regions). Higher black hole (BH) masses (≈ 50-100 M⊙) may be the end product of massive stellar evolution in peculiar environments: they may explain ULXs with luminosities ≈ 1-2 × 1040 erg s-1. Only a handful of ULXs require a true intermediate-mass BH (M ⪆ 500 M⊙). Finally, a small subclass of ULXs shows flaring or rapid variability in its power-law spectral component.

  3. Linear accelerator x-ray sources with high duty cycle

    SciTech Connect

    Condron, Cathie; Brown, Craig; Gozani, Tsahi; Langeveld, Willem G. J.; Hernandez, Michael

    2013-04-19

    X-ray cargo inspection systems typically use a several-MV pulsed linear accelerator (linac) to produce a bremsstrahlung spectrum of x rays by bombarding a target with electrons. The x rays traverse the cargo and are detected by a detector array. Spectroscopy of the detected x rays is very desirable: if one can determine the spectrum of the transmitted x rays, one can determine the Z of the material they traversed. Even in relatively low-dose modes of operation, thousands of x rays arrive at each detector element during each pulse, unless the x rays are heavily absorbed or scattered by the cargo. For portal or fixed-site systems, dose rates, and therefore x-ray count rates, are even higher. Because of the high x-ray count rate, spectroscopy is impractical in conventional cargo inspection systems, except in certain special cases. For a mobile system, typical pulse durations are a few microseconds, and the number of pulses is on the order of 100 per second, leading to a duty factor of about 0.04%. Clearly, a linear accelerator x-ray source with much higher duty factor would be useful, since then the same number of x rays could be spread out over time, reducing the x-ray count rate. In this paper, we explore the possibility of designing a linear accelerator system, using more or less Conventional Off the Shelf (COTS) components, capable of duty cycles of 1% or greater. A survey was conducted of available linac RF source options and, given the possibilities, calculations were performed for suitable beam centerline designs. Keeping in mind that the size and cost of the accelerator system should be practical for use in a mobile cargo inspection system, only a few options are shown to be reasonably feasible, both requiring the use of klystrons instead of the magnetrons used in conventional systems. An S-Band design appears clearly possible, and there is also a promising X-Band design.

  4. Ionization nebulae surrounding supersoft X-ray sources

    NASA Technical Reports Server (NTRS)

    Rappaport, S.; Chiang, E.; Kallman, T.; Malina, R.

    1994-01-01

    In this work we carry out a theoretical investigation of a new type of astrophysical gaseous nebula, viz., ionized regions surrounding supersoft X-ray sources. Supersoft X-ray sources, many of which have characteristic luminosities of approximately 10(exp 37)-(10(exp 38) ergs/s and effective temperatures of approximately 4 x 10(exp 5) K, were first discovered with the Einstein Observatory. These sources have now been shown to constitute a distinct class of X-ray source and are being found in substantial numbers with ROSAT. We predict that these sources should be surrounded by regions of ionized hydrogen and helium with properties that are distinct from other astrophysical gaseous nebulae. We present caluations of the ionization and temperature structure of these ionization nebulae, as well as the expected optical line fluxes. The ionization profiles for both hydrogen and helium exhibit substantially more gradual transitions from the ionized to the unionized state than is the case for conventional H II regions. The calculated optical line intensitites are presented as absolute fluxes from sources in the Large Magellanic Cloud and as fractions of the central source luminosity. We find, in particular, that (O III) lambda 5008 and He II lambda 4686 are especially prominent in these ionization nebulae as compared to other astrophysical nebulae. We propose that searches for supersoft X-rays via their characteristic optical lines may reveal sources in regions where the soft X-rays are nearly completely absorbed by the interstellar medium.

  5. Results from the Daresbury Compton backscattering X-ray source

    NASA Astrophysics Data System (ADS)

    Laundy, D.; Priebe, G.; Jamison, S. P.; Graham, D. M.; Phillips, P. J.; Smith, S. L.; Saveliev, Y.; Vassilev, S.; Seddon, E. A.

    2012-10-01

    The Daresbury Compton Backscattering X-ray Source uses a high power Ti Sapphire laser interacting in head on geometry with electron bunches in the ALICE energy recovery linear accelerator. X-ray photons with peak energy of 21 keV were generated with the accelerator operating at an energy of 29.6 MeV. The spatial profile of the X-rays emitted near the electron beam axis was measured. The characteristics of the X-ray yield measured as a function of relative timing between the laser pulse and the interacting electron bunch was found to be consistent with the modelled intensity behaviour using measured electron and laser beam parameters.

  6. Massive stellar X-ray sources in the Galactic center

    NASA Astrophysics Data System (ADS)

    Mauerhan, Jon Christian

    2008-06-01

    The purpose of this thesis is to discover unidentified members of the massive stellar population in the Galactic center, using a novel selection technique: the identification of infrared counterparts to hard X-ray sources. This method provides a means of distinguishing a subset of hot, massive stars from the more numerous cool giants that dominate the stellar population of the central Galaxy, providing potential beacons toward undiscovered regions of massive star formation, and the remains of tidally-disrupted stellar clusters. Hard-X-ray selection also highlights exotic species of massive star, including Wolf-Rayet (WR) binaries with colliding supersonic winds, and wind-accreting neutron stars and black holes in high-mass X-ray binaries (HMXBs). Massive stars were sought in the central 300 pc of the Galaxy by cross- correlating X-ray and IR point-source catalogs. Approximately 1% of the 6067 Chandra X-ray sources near the Galactic center have near-infrared matches with K s < 15.6 mag. A spectroscopic campaign was launched to investigate the most promising candidates; 17 new WR/O stars were discovered throughout the inner 300 pc. Most of the massive stars exhibit infrared excess, attributable to free-free and dust emission. In many cases, mid-IR images exhibit strong interaction of the X-ray sources with the Galactic center medium. Most of the newly found sources have no apparent association with a dense stellar cluster, although several stars lie near the Quintuplet cluster and may have escaped from it. The X-ray emission of the massive stars is consistent with thermal emission from plasma at temperatures above 2 keV, not a ubiquitous feature of single massive stars. The X-ray data are consistent with models of strong WR/O winds colliding with the surfaces of binary companions, but are also consistent with known, low-luminosity HMXBs. Future experiments are discussed, aimed at unambiguously determining the masses of the stellar components, and surveying the

  7. Monitoring variable X-ray sources in nearby galaxies

    NASA Astrophysics Data System (ADS)

    Kong, A. K. H.

    2010-12-01

    In the last decade, it has been possible to monitor variable X-ray sources in nearby galaxies. In particular, since the launch of Chandra, M31 has been regularly observed. It is perhaps the only nearby galaxy which is observed by an X-ray telescope regularly throughout operation. With 10 years of observations, the center of M31 has been observed with Chandra for nearly 1 Msec and the X-ray skies of M31 consist of many transients and variables. Furthermore, the X-ray Telescope of Swift has been monitoring several ultraluminous X-ray sources in nearby galaxies regularly. Not only can we detect long-term X-ray variability, we can also find spectral variation as well as possible orbital period. In this talk, I will review some of the important Chandra and Swift monitoring observations of nearby galaxies in the past 10 years. I will also present a "high-definition" movie of M31 and discuss the possibility of detecting luminous transients in M31 with MAXI.

  8. COMPACT OPTICAL COUNTERPARTS OF ULTRALUMINOUS X-RAY SOURCES

    SciTech Connect

    Tao Lian; Feng Hua; Grise, Fabien; Kaaret, Philip

    2011-08-20

    Using archival Hubble Space Telescope (HST) imaging data, we report the multiband photometric properties of 13 ultraluminous X-ray sources (ULXs) that have a unique compact optical counterpart. Both magnitude and color variation are detected at timescales of days to years. The optical color, variability, and X-ray to optical flux ratio indicate that the optical emission of most ULXs is dominated by X-ray reprocessing on the disk, similar to that of low-mass X-ray binaries. For most sources, the optical spectrum is a power law, F{sub {nu}}{proportional_to}{nu}{sup {alpha}} with {alpha} in the range 1.0-2.0 and the optically emitting region has a size on the order of 10{sup 12} cm. Exceptions are NGC 2403 X-1 and M83 IXO 82, which show optical spectra consistent with direct emission from a standard thin disk, M101 ULX-1 and M81 ULS1, which have X-ray to optical flux ratios more similar to high-mass X-ray binaries, and IC 342 X-1, in which the optical light may be dominated by the companion star. Inconsistent extinction between the optical counterpart of NGC 5204 X-1 and the nearby optical nebulae suggests that they may be unrelated.

  9. The X-ray spectral evolution and radio-X-ray correlation in radiatively efficient black-hole sources

    NASA Astrophysics Data System (ADS)

    Dong, Ai-Jun; Wu, Qingwen; Cao, Xiao-Feng

    2016-02-01

    We explore X-ray spectral evolution and radio-X-ray correlation simultaneously for four X-ray binaries (XRBs). We find that hard X-ray photon indices, Γ, are anti- and positively correlated to X-ray fluxes when the X-ray flux, F 3-9keV, is below and above a critical flux, F X,crit, which may be regulated by ADAF and disk-corona respectively. We find that the data points with anti-correlation of Γ-F 3-9keV follow the universal radio-X-ray correlation of F R ~ F X b (b ~ 0.5-0.7), while the data points with positive X-ray spectral evolution follow a steeper radio-X-ray correlation (b ~ 1.4, the so-called `outliers track'). The bright active galactic nuclei (AGNs) share similar X-ray spectral evolution and radio-X-ray correlation as XRBs in `outliers' track, and we present a new fundamental plane of log L R=1.59+0.28 -0.22 log L X-0.22+0.19 -0.20 log M BH-28.97+0.45 -0.45 for these radiatively efficient BH sources.

  10. Advanced X-Ray Sources Ensure Safe Environments

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Ames Research Center awarded inXitu Inc. (formerly Microwave Power Technology), of Mountain View, California, an SBIR contract to develop a new design of electron optics for forming and focusing electron beams that is applicable to a broad class of vacuum electron devices. This technology offers an inherently rugged and more efficient X-ray source for material analysis; a compact and rugged X-ray source for smaller rovers on future Mars missions; and electron beam sources to reduce undesirable emissions from small, widely distributed pollution sources; and remediation of polluted sites.

  11. X-Ray Source Populations in Galaxies Giuseppina Fabbiano

    NASA Technical Reports Server (NTRS)

    Fabbiano, Giuseppina

    1997-01-01

    The talk will review the present results on X-ray sources in external galaxies, with particular emphasis on black hole candidates and supersoft sources. These sources will be excellent AXAF targets and it is important that we summarize our knowledge and open issues in time for the AXAF NRA.

  12. X-ray Optics for BES Light Source Facilities

    SciTech Connect

    Mills, Dennis; Padmore, Howard; Lessner, Eliane

    2013-03-27

    Each new generation of synchrotron radiation sources has delivered an increase in average brightness 2 to 3 orders of magnitude over the previous generation. The next evolution toward diffraction-limited storage rings will deliver another 3 orders of magnitude increase. For ultrafast experiments, free electron lasers (FELs) deliver 10 orders of magnitude higher peak brightness than storage rings. Our ability to utilize these ultrabright sources, however, is limited by our ability to focus, monochromate, and manipulate these beams with X-ray optics. X-ray optics technology unfortunately lags behind source technology and limits our ability to maximally utilize even today’s X-ray sources. With ever more powerful X-ray sources on the horizon, a new generation of X-ray optics must be developed that will allow us to fully utilize these beams of unprecedented brightness. The increasing brightness of X-ray sources will enable a new generation of measurements that could have revolutionary impact across a broad area of science, if optical systems necessary for transporting and analyzing X-rays can be perfected. The high coherent flux will facilitate new science utilizing techniques in imaging, dynamics, and ultrahigh-resolution spectroscopy. For example, zone-plate-based hard X-ray microscopes are presently used to look deeply into materials, but today’s resolution and contrast are restricted by limitations of the current lithography used to manufacture nanodiffractive optics. The large penetration length, combined in principle with very high spatial resolution, is an ideal probe of hierarchically ordered mesoscale materials, if zone-plate focusing systems can be improved. Resonant inelastic X-ray scattering (RIXS) probes a wide range of excitations in materials, from charge-transfer processes to the very soft excitations that cause the collective phenomena in correlated electronic systems. However, although RIXS can probe high-energy excitations, the most exciting and

  13. Gravitationally Lensed X-Ray Sources at the Galactic Center

    NASA Astrophysics Data System (ADS)

    Castelaz, Michael W.; Rottler, L.

    2012-01-01

    More than two thousand x-ray sources located within 20 pc of the Galactic Center (GC) have been identified by Muno et al. (2003). If an x-ray source is located behind the Galactic Center and offset by a small angle from the GC projected on the sky, then that x-ray source could be gravitationally lensed. The consequences of finding gravitationally lensed sources at the Galactic Center include the ability to independently measure the mass of the GC as well as provide a new probe of the density distribution of the GC (e.g. Wardle & Yusef-Zadeh 1992). Inspecting x-ray images of the GC we were immediately drawn to a set of four x-ray objects. The identified objects are cataloged as CXOJ 174541.0-290014, 174540.1-290005, 174540.0-290031, and 174538.1-290022. These are the brightest and most obvious variable x-ray objects whose positions suggest patterns of images that may either be an inclined quad or two sets of dual gravitational lens patterns. Based on the image patterns, and image brightnesses and relative variations, we modeled possible lens systems using two algorithms. Both of the algorithms describing gravitational lenses are based on the Fermat potential and its time derivatives. For a lens radius of R = 0.01 pc, the total enclosed mass is 2.6 x 107 M⊙ and for R = 0.001 pc, the total enclosed mass is 2.6 x 105 M⊙. These masses are consistent with other measurements of the mass of the GC, such as 4.5 x 106 M⊙ (Ghez et al. 2008). We will present these results and our plans to further study the nature of these x-ray objects.

  14. High intensity line source for x-ray spectrometer calibration

    SciTech Connect

    Thoe, R.S.

    1986-06-01

    A high intensity electron-impact x-ray source using a one-dimensional Pierce lens has been built for the purpose of calibrating a bent crystal x-ray spectrometer. This source focuses up to 100 mA of 20-keV electrons to a line on a liquid-cooled anode. The line (which can serve as a virtual slit for the spectrometer) measures approximately 800 ..mu.. x 2 cm. The source is portable and therefore adaptable to numerous types of spectrometer applications. One particular application, the calibration of a high resolution (r = 10/sup 4/) time-resolved cyrstal spectrometer, will be discussed in detail.

  15. Discovery of a second outbursting hyperluminous X-ray source

    NASA Astrophysics Data System (ADS)

    Heida, M.; Jonker, P. G.; Torres, M. A. P.

    2015-11-01

    We report on six Chandra and one HST/WFC3 observation of CXO J122518.6+144545, discovered by Jonker et al. (2010) as a candidate hyperluminous X-ray source (HLX), X-ray bright supernova or recoiling supermassive black hole at LX = 2.2 × 1041 erg s-1 (if associated with the galaxy at 182 Mpc). We detect a new outburst of the source in a Chandra image obtained on 2014 November 20 and show that the X-ray count rate varies by a factor >60. New HST/WFC3 observations obtained in 2014 show that the optical counterpart is still visible at g'= 27.1 ± 0.1, 1 ± 0.1 mag fainter than in the discovery HST/ACS observation from 2003. This optical variability strongly suggests that the optical and X-ray source are related. Furthermore, these properties strongly favour an HLX nature of the source over the alternative scenarios. We therefore conclude that CXO J122518.6+144545 is most likely an outbursting HLX. It is only the second such object to be discovered, after HLX-1 in ESO 243-49. Its high X-ray luminosity makes it a strong candidate to host an intermediate-mass black hole.

  16. X-ray source safety shutter

    DOEpatents

    Robinet, McLouis

    1977-05-31

    An apparatus is provided for controlling the activation of a high energy radiation source having a shutter. The apparatus includes magnets and magnetically responsive switches appropriately placed and interconnected so that only with the shutter and other parts of the source in proper position can safe emission of radiation out an open shutter occur.

  17. Tentative study on x-ray enhancement by fluorescent emission of radiation by plasma x-ray source

    NASA Astrophysics Data System (ADS)

    Sato, Eiichi; Sagae, Michiaki; Ichimaru, Toshio; Hayasi, Yasuomi; Ojima, Hidenori; Takayama, Kazuyoshi; Ido, Hideaki; Sakamaki, Kimio; Tamakawa, Yoshiharu

    1999-09-01

    Tentative study on characteristic x-ray enhancement by fluorescent emission of radiation by plasma x-ray source is described. The enhancement was performed by the plasma flash x-ray generator having a cold-cathode triode. And the generator employs a high-voltage power supply, a low-impedance coaxial transmission line with a gap switch, a high-voltage condenser with a capacity of 200 nF, a turbo-molecular pump, a thyristor pulser as a trigger device, and a flash x-ray tube. The high-voltage main condenser is charged up to 60 kV by the power supply, and the electric charges in the condenser are discharged to the tube after triggering the cathode electrode. The flash x-rays are then produced. The x-ray tube is of a demountable triode that is connected to the turbo molecular pump with a pressure of approximately 1 mPa. As the electron flows from the cathode electrode are roughly converged to the target by the electric field in the tube, the plasma x-ray source, which consists of metal ions and electrons, forms by the target evaporating. Both the tube voltage and current displayed damped oscillations, and their peak values increased according to increases in the charging voltage. In the present work, the peak tube voltage was almost equivalent to the initial charging voltage of the main condenser, and the peak current was less than 30 kA. The characteristic x-ray intensity substantially increased according to the growth in the plasma x-ray source. When the linear plasma x-ray source formed, the bremsstrahlung x-rays were absorbed without using a monochromatic filter, and high- intensity characteristic x-rays were produced.

  18. Discrete X-ray sources and the X-ray background

    NASA Technical Reports Server (NTRS)

    Giacconi, Riccardo

    1987-01-01

    Since the discovery of a highly uniform X-ray background (XRB) in the 2 to 10 keV range, its nature is not yet fully explained. It appears clear from the results of Einstein medium and deep surveys that at least 50% of the XRB is due to individual extragalactic sources when their contribution is integrated to Z = 3. This includes contribution from Quasi Stellar Objects (QSOs), Active Galactic Nuclei (AGNs), galaxies, and clusters of galaxies. The average spectrum of each of the individual contributing sources is softer than that of the observed XRB. Therefore, the remaining contribution must have a rather hard spectrum of alpha nearly equal to 0.0 to 0.2. It is unlikely that this spectrum can be produced by diffuse processes. Therefore, the remainder of the XRB must be due to individual sources with the appropriate spectrum. This requires either that the spectrum of the already identified sources changes at early epochs or a new class of objects. Advanced X-ray Astrophysics Facility (AXAF) observations will extend survey sensitivity to limiting fluxes of order of 3 x 10 to the minus 16 erg/sq cm/s, some 50 times fainter than any previous survey. There will be sufficient sensitivity and angular resolution to permit identification and study of these objects.

  19. X-Ray Sources in the Dwarf Spheroidal Galaxy DRACO

    NASA Astrophysics Data System (ADS)

    Sonbas, E.; Dhuga, K.; Rangelov, B.; Kargaltsev, O.

    2016-06-01

    We present the results of a spectral analysis of X - ray sources in Draco, a nearby dwarf spheroidal galaxy recently observed by XMM-Newton. While most of the sources exhibit properties consistent with AGN, few of them possess characteristics of LMXBs and CVs. We also discuss the possibility of the existence of a central IMBH in Draco.

  20. Measuring x-ray spectra of flash radiographic sources

    SciTech Connect

    Gehring, Amanda Elizabeth; Espy, Michelle A.; Haines, Todd Joseph; Mendez, Jacob; Moir, David C.; Sedillo, Robert; Shurter, Roger P.; Volegov, Petr Lvovich; Webb, Timothy J

    2015-11-02

    The x-ray spectra of flash radiographic sources is difficult to measure. The sources measured were Radiographic Integrated Test Stand-6 (370 rad at 1 m; 50 ns pulse) and Dual Axis Radiographic Hydrodynamic Test Facility (DARHT) (550 rad at 1 m; 50 ns pulse). Features of the Compton spectrometer are described, and spectra are shown. Additional slides present data on instrumental calibration.

  1. Movable anode x-ray source with enhanced anode cooling

    DOEpatents

    Bird, Charles R.; Rockett, Paul D.

    1987-01-01

    An x-ray source having a cathode and a disc-shaped anode with a peripheral surface at constant radius from the anode axis opposed to the cathode. The anode has stub axle sections rotatably carried in heat conducting bearing plates which are mounted by thermoelectric coolers to bellows which normally bias the bearing plates to a retracted position spaced from opposing anode side faces. The bellows cooperate with the x-ray source mounting structure for forming closed passages for heat transport fluid. Flow of such fluid under pressure expands the bellows and brings the bearing plates into heat conducting contact with the anode side faces. A worm gear is mounted on a shaft and engages serrations in the anode periphery for rotating the anode when flow of coolant is terminated between x-ray emission events.

  2. Movable anode x-ray source with enhanced anode cooling

    DOEpatents

    Bird, C.R.; Rockett, P.D.

    1987-08-04

    An x-ray source is disclosed having a cathode and a disc-shaped anode with a peripheral surface at constant radius from the anode axis opposed to the cathode. The anode has stub axle sections rotatably carried in heat conducting bearing plates which are mounted by thermoelectric coolers to bellows which normally bias the bearing plates to a retracted position spaced from opposing anode side faces. The bellows cooperate with the x-ray source mounting structure for forming closed passages for heat transport fluid. Flow of such fluid under pressure expands the bellows and brings the bearing plates into heat conducting contact with the anode side faces. A worm gear is mounted on a shaft and engages serrations in the anode periphery for rotating the anode when flow of coolant is terminated between x-ray emission events. 5 figs.

  3. Compact Laser-Compton X-ray Source Development

    NASA Astrophysics Data System (ADS)

    Yeh, Po-Chun

    The state-of-the-art X-ray source based on inverse-Compton scattering between a high-brightness, relativistic electron beam produced by an X-band RF accelerator and a high-intensity laser pulse generated by chirped-pulse amplification (CPA) has been carried out by our research team at Lawrence Livermore National Laboratory. This system is called "Compact Laser-Compton X-ray Source". The applications include nuclear resonance fluorescence, medical imaging and therapy, and nuclear waste imaging and assay. One of the key factors in this system is how we know the interaction happened in the vacuum chamber, which is the spectrometer of electron beams. The other key factor is the interaction after the spectrometer, which is the outgoing X-ray. In this thesis, the work in the simulation for the result of the interaction between electrons and the laser, the calibration of spectrometer, and laser focus characterization are discussed.

  4. X-ray Counterparts of Infrared Faint Radio Sources

    NASA Astrophysics Data System (ADS)

    Schartel, Norbert

    2011-10-01

    Infrared Faint Radio Sources (IFRS) are radio sources with extremely faint or even absent infrared emission in deep Spitzer Surveys. Models of their spectral energy distributions, the ratios of radio to infrared flux densities and their steep radio spectra strongly suggest that IFRS are AGN at high redshifts (2X-ray background. The identification of X-ray counterparts of IFRS is considered to be the smoking gun for this hypothesis. We propose to observe 8 IFRS using 30ks pointed observations. X-ray detections of IFRS with different ratios of radio-to-infrared fluxes, will constrain the class-specific SED.

  5. Modelling Carbon Nanotubes-Based Mediatorless Biosensor

    PubMed Central

    Baronas, Romas; Kulys, Juozas; Petrauskas, Karolis; Razumiene, Julija

    2012-01-01

    This paper presents a mathematical model of carbon nanotubes-based mediatorless biosensor. The developed model is based on nonlinear non-stationary reaction-diffusion equations. The model involves four layers (compartments): a layer of enzyme solution entrapped on a terylene membrane, a layer of the single walled carbon nanotubes deposited on a perforated membrane, and an outer diffusion layer. The biosensor response and sensitivity are investigated by changing the model parameters with a special emphasis on the mediatorless transfer of the electrons in the layer of the enzyme-loaded carbon nanotubes. The numerical simulation at transient and steady state conditions was carried out using the finite difference technique. The mathematical model and the numerical solution were validated by experimental data. The obtained agreement between the simulation results and the experimental data was admissible at different concentrations of the substrate. PMID:23012537

  6. Modelling carbon nanotubes-based mediatorless biosensor.

    PubMed

    Baronas, Romas; Kulys, Juozas; Petrauskas, Karolis; Razumiene, Julija

    2012-01-01

    This paper presents a mathematical model of carbon nanotubes-based mediatorless biosensor. The developed model is based on nonlinear non-stationary reaction-diffusion equations. The model involves four layers (compartments): a layer of enzyme solution entrapped on a terylene membrane, a layer of the single walled carbon nanotubes deposited on a perforated membrane, and an outer diffusion layer. The biosensor response and sensitivity are investigated by changing the model parameters with a special emphasis on the mediatorless transfer of the electrons in the layer of the enzyme-loaded carbon nanotubes. The numerical simulation at transient and steady state conditions was carried out using the finite difference technique. The mathematical model and the numerical solution were validated by experimental data. The obtained agreement between the simulation results and the experimental data was admissible at different concentrations of the substrate. PMID:23012537

  7. Tentative study on high-photon-energy quasi-x-ray laser generator by forming plasma x-ray source

    NASA Astrophysics Data System (ADS)

    Sato, Eiichi; Hayasi, Yasuomi; Ichimaru, Toshio; Mori, Hidezo; Tanaka, Etsuro; Ojima, Hidenori; Takayama, Kazuyoshi; Usuki, Tatsumi; Sato, Koetsu; Sakamaki, Kimio; Tamakawa, Yoshiharu

    2001-04-01

    Tentative study on high-photon-energy quasi-x-ray-laser generator by forming plasma x-ray source is described. The generator employs a high-voltage power supply, a low-impedance coaxial transmission line, a high-voltage condenser with a capacity of about 200 nF, a turbo-molecular pump, a thyristor pulse generator as a trigger device, and a flash x-ray tube. The high-voltage main condenser is charged up to 60 kV by the power supply, and the electric charges in the condenser are discharged to the tube after triggering the cathode electrode. The flash x-rays are then produced. The x-ray tube is of a demountable triode that is connected to the turbo molecular pump with a pressure of approximately 1 mPa. As the electron flows from the cathode electrode are roughly converged to the copper target by the electric field in the tube, the plasma x- ray source, which consists of metal ions and electrons, forms by the target evaporating. Both the tube voltage and current displayed damped oscillations, and their peak values increased according to increases in the charging voltage. In the present work, the peak tube voltage was much higher than the initial charging voltage of the main condenser, and the peak current was about 25 kA with a charging voltage of 60 kV. When the charging voltage was increased, the plasma x-ray source formed, and the characteristic x-ray intensities of K-series lines increased. When the plate target was employed, we observed high-intensity characteristic x-rays from the axial direction of the linear plasma x-ray source. In the case where the rod target was employed, we detected higher-intensity characteristic x-rays.

  8. Toward a fourth-generation x-ray source.

    SciTech Connect

    Monction, D. E.

    1999-05-19

    The field of synchrotron radiation research has grown rapidly over the last 25 years due to both the push of the accelerator and magnet technology that produces the x-ray beams and the pull of the extraordinary scientific research that is possible with them. Three successive generations of synchrotrons radiation facilities have resulted in beam brilliances 11 to 12 orders of magnitude greater than the standard laboratory x-ray tube. However, greater advances can be easily imagined given the fact that x-ray beams from present-day facilities do not exhibit the coherence or time structure so familiar with the optical laser. Theoretical work over the last ten years or so has pointed to the possibility of generating hard x-ray beams with laser-like characteristics. The concept is based on self-amplified spontaneous emission (SASE) in flee-electron lasers. A major facility of this type based upon a superconducting linac could produce a cost-effective facility that spans wave-lengths from the ultraviolet to the hard x-ray regime, simultaneously servicing large numbers experimenters from a wide range of disciplines. As with each past generation of synchrotrons facilities, immense new scientific opportunities would result from fourth-generation sources.

  9. X-ray sources for radiography of warm dense matter

    NASA Astrophysics Data System (ADS)

    Benuzzi-Mounaix, Alessandra; Brambrink, Erik; Barbrel, Benjamin; Koenig, Michel; Gregory, Chris; Loupias, Bérénice; Ravasio, Alessandra; Rabec Le Gloahec, Marc; Vinci, Tommaso; Boehly, Tom; Endo, Takashi; Kimura, Tomoaki; Ozaki, Norimasa; Wei, Huigang; Aglitskiy, Yefim; Faenov, Anatoly; Pikuz, Tatiana

    2008-11-01

    The knowledge of Warm Dense Matter is important in different domains such as inertial confinement fusion, astrophysics and geophysics. The development of techniques for direct probing of this type of matter is of great interest. X-ray radiography is one of the most promising diagnostic to measure density directly. Here we present some results of low-Z material radiography and an experiment devoted to characterize a short pulse laser driven hard x-ray source for the radiography of medium and high Z matter. Experiments have been performed on LULI2000 and TW facilities at the Ecole Polytechnique.

  10. A simple physical model for X-ray burst sources

    NASA Technical Reports Server (NTRS)

    Joss, P. C.; Rappaport, S.

    1977-01-01

    In connection with information considered by Illarianov and Sunyaev (1975) and van den Heuvel (1975), a simple physical model for an X-ray burst source in the galactic disk is proposed. The model includes an unevolved OB star with a relatively weak stellar wind and a compact object in a close binary system. For some reason, the stellar wind from the OB star is unable to accrete steadily on to the compact object. When the stellar wind is sufficiently weak, the compact object accretes irregularly, leading to X-ray bursts.

  11. Thermonuclear-flash models for X-ray burst sources

    NASA Technical Reports Server (NTRS)

    Joss, P. C.

    1980-01-01

    Theoretical models for X-ray burst sources that invoke thermonuclear flashes in the surface layers of an accreting neutron star are discussed. Emphasis is placed on the studies by Joss (1978) and Joss and Li (1979) on the evolution of the helium-burning shell. Numerical calculations with regard to the mass accretion rate, core temperature of the neutron star and the sensitivity of the flash properties to the assumed mass and radius of the neutron star are considered. Attention is also given to the behavior of the surface luminosity following a thermonuclear flash, the decline from maximum X-ray luminosity, structure of the surface layers prior to and during the first helium-burning flash and the temporal evolution of the first X-ray burst.

  12. Compact X-ray Light Source Workshop Report

    SciTech Connect

    Thevuthasan, Suntharampillai; Evans, James E.; Terminello, Louis J.; Koppenaal, David W.; Manke, Kristin L.; Plata, Charity

    2012-12-01

    This report, produced jointly by EMSL and FCSD, is the result of a workshop held in September 2011 that examined the utility of a compact x-ray light source (CXLS) in addressing many scientific challenges critical to advancing energy science and technology.

  13. Characterization of X-Ray Diffraction System with a Microfocus X-Ray Source and a Polycapillary Optic

    NASA Technical Reports Server (NTRS)

    Gubarev, Mikhail; Marshall, Joy K.; Ciszak, Ewa; Ponomarev, Igor

    2000-01-01

    We present here an optimized microfocus x-ray source and polycapillary optic system designed for diffraction of small protein crystals. The x-ray beam is formed by a 5.5mm focal length capillary collimator coupled with a 40 micron x-ray source operating at 46Watts. Measurements of the x-ray flux, the divergence and the spectral characteristics of the beam are presented, This optimized system provides a seven fold greater flux than our recently reported configuration [M. Gubarev, et al., J. of Applied Crystallography (2000) 33, in press]. We now make a comparison with a 5kWatts rotating anode generator (Rigaku) coupled with confocal multilayer focusing mirrors (Osmic, CMF12- 38Cu6). The microfocus x-ray source and polycapillary collimator system delivers 60% of the x-ray flux from the rotating anode system. Additional ways to improve our microfocus x-ray system, and thus increase the x-ray flux will be discussed.

  14. 21 CFR 872.1810 - Intraoral source x-ray system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Intraoral source x-ray system. 872.1810 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.1810 Intraoral source x-ray system. (a) Identification. An intraoral source x-ray system is an electrically powered device that produces x-rays and...

  15. 21 CFR 872.1800 - Extraoral source x-ray system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Extraoral source x-ray system. 872.1800 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.1800 Extraoral source x-ray system. (a) Identification. An extraoral source x-ray system is an AC-powered device that produces x-rays and is intended...

  16. 21 CFR 872.1810 - Intraoral source x-ray system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Intraoral source x-ray system. 872.1810 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.1810 Intraoral source x-ray system. (a) Identification. An intraoral source x-ray system is an electrically powered device that produces x-rays and...

  17. 21 CFR 872.1800 - Extraoral source x-ray system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Extraoral source x-ray system. 872.1800 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.1800 Extraoral source x-ray system. (a) Identification. An extraoral source x-ray system is an AC-powered device that produces x-rays and is intended...

  18. 21 CFR 872.1810 - Intraoral source x-ray system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Intraoral source x-ray system. 872.1810 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.1810 Intraoral source x-ray system. (a) Identification. An intraoral source x-ray system is an electrically powered device that produces x-rays and...

  19. 21 CFR 872.1810 - Intraoral source x-ray system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Intraoral source x-ray system. 872.1810 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.1810 Intraoral source x-ray system. (a) Identification. An intraoral source x-ray system is an electrically powered device that produces x-rays and...

  20. 21 CFR 872.1810 - Intraoral source x-ray system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Intraoral source x-ray system. 872.1810 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.1810 Intraoral source x-ray system. (a) Identification. An intraoral source x-ray system is an electrically powered device that produces x-rays and...

  1. 21 CFR 872.1800 - Extraoral source x-ray system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Extraoral source x-ray system. 872.1800 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.1800 Extraoral source x-ray system. (a) Identification. An extraoral source x-ray system is an AC-powered device that produces x-rays and is intended...

  2. 21 CFR 872.1800 - Extraoral source x-ray system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Extraoral source x-ray system. 872.1800 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.1800 Extraoral source x-ray system. (a) Identification. An extraoral source x-ray system is an AC-powered device that produces x-rays and is intended...

  3. 21 CFR 872.1800 - Extraoral source x-ray system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Extraoral source x-ray system. 872.1800 Section... (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Diagnostic Devices § 872.1800 Extraoral source x-ray system. (a) Identification. An extraoral source x-ray system is an AC-powered device that produces x-rays and is intended...

  4. Transition radiation very soft X-ray source

    NASA Astrophysics Data System (ADS)

    Umiastowski, K.; Nguyen, A.

    1994-05-01

    There is a growing interest in the transition radiation (TR), as a soft X-ray source, in the last few years. Many papers have been published on calculations or experiments in the 1-10 keV X-ray energy range using 50-200 MeV electron accelerators. We investigate the possibility to generate very soft X-rays (λ = 12 nm) with low-energy electron accelerator (5-20 MeV). Very little information is available on TR in this range of photon wavelength and electron energy. A stack of 20 foils of beryllium placed in vacuum was used in our computer simulation. Calculation shows that for 1 mA electron beam current, radiation with few mW intensity can be produced. Emitted photons are quasi-monoenergetic (FWHM less than 5%), and well collimated. The aim of our study is to investigate the possibility of fabricate a soft X-ray source, much more compact than synchrotron source and producing an intense and quasi-coherent radiation, for industrial applications.

  5. From incoherent to coherent x-rays with ICS sources

    NASA Astrophysics Data System (ADS)

    Nanni, Emilio A.; Graves, William S.; Moncton, David E.

    2015-08-01

    We present the design and performance parameters for a compact x-ray light source (CXLS), which is presently under construction, based on inverse Compton scattering (ICS) of a high brightness electron bunch on a picosecond laser pulse. The flux and brilliance of this source are orders of magnitude beyond existing laboratory scale sources. The accelerator operates at a repetition rate of 1 kHz with 100 bunches of 100 pC charge, each separated by 5 ns, in each shot. The entire CXLS is a few meters in length and produces hard x-rays tunable over a wide range of photon energies. The scattering laser is a Yb:YAG solid-state amplifier producing 100 mJ pulses at 1030 nm. The laser pulse is frequency-doubled and coupled into a ringdown cavity to match the linac pulse structure. At a photon energy of 12.4 keV, the predicted x-ray flux is 5×1011 photons/second in a 5% bandwidth and the brilliance is 2×1012 photons/(secmm2mrad20.1%) with a RMS pulse length of 490 fs. Novel concepts for improving the performance of the CXLS with the generation of relativistic electron beams having current modulation at nanometer scale and below are also discussed. This tunable longitudinal modulation enables the production of coherent hard x-rays with ICS.

  6. A 62 Day X-Ray Periodicity and an X-Ray Flare from the Ultraluminous X-Ray Source in M82

    NASA Astrophysics Data System (ADS)

    Kaaret, Philip; Simet, Melanie G.; Lang, Cornelia C.

    2006-07-01

    In 240 days of X-ray monitoring of M82, we have discovered an X-ray periodicity at 62.0+/-2.5 days with a peak-to-peak amplitude corresponding to an isotropic luminosity of 2.4×1040 ergs s-1 in M82 and an X-ray flare reaching a peak luminosity of 9.8×1040 ergs s-1. The periodicity and flare likely originate from the ultraluminous X-ray source (ULX) in M82, which has been identified as a possible intermediate-mass black hole. We suggest that the 62 day modulation is due to orbital motion within an X-ray binary with a Roche lobe overflowing companion star, which would imply that the average density of the companion star is near 5×10-5 g cm-3 and is therefore a giant or supergiant. Chandra observations just after the flare show an energy spectrum that is consistent with a power law with no evidence of a thermal component or line emission. Radio observations made with the VLA during the flare allow us to rule out a blazar identification for the source and place strong constraints on relativistically beamed models of the X-ray emission. The Chandra observations reveal that a second X-ray source reached a flux of 4.4×10-12 ergs cm-2 s-1 in the 0.3-7 keV band, which is dramatically higher than any flux previously seen from this source and corresponds to an isotropic luminosity of 1.1×1040 ergs s-1. This source is a second ultraluminous X-ray source in M82 and may give rise to the QPOs detected from the central region of M82.

  7. Ultraluminous X-ray Sources in NGC 6946.

    NASA Astrophysics Data System (ADS)

    Sánchez Cruces, Mónica; Rosado, Margarita; Fuentes-Carrera, Isaura L.

    2016-07-01

    Ultra-luminous X-ray sources (ULXs) are the most X-ray luminous off-nucleus objects in nearby galaxies with X-ray luminosities between 10^{39} - 10^{41} erg s^{-1} in the 0.5-10 keV band. Since these luminosities cannot be explained by the standard accretion of a stellar mass black hole, these sources are often associated with intermediate-mass black holes (IMBHs, 10^{2}-10^{4} solar masses). However significantly beamed stellar binary systems could also explain these luminosities. Observational knowledge of the angular distribution of the source emission is essential to decide between these two scenarios. In this work, we present the X-ray analysis of five ULXs in the spiral galaxy NGC 6949, along with the kinematical analysis of the ionized gas surrounding each of these sources. For all sources, X-ray observations reveal a typical ULX spectral shape (with a soft excess below 2 keV and a hard curvature above 2 keV) which can be fit with a power-law + multi-color disk model. However, even if ULXs are classified as point-like objects, one of the sources in this galaxy displays an elongated shape in the Chandra images. Regarding the analysis of the emission lines of the surrounding ˜300 pc around each ULX, scanning Fabry-Perot observations show composite profiles for three of the five ULXs. The main component of these profiles follows the global rotation of the galaxy, while the faint secondary component seems to be associated with asymmetrical gas expansion. These sources have also been located in archive images of NGC 6946 in different wavelengths in order to relate them to different physical processes occurring in this galaxy. Though ULXs are usually located in star formation regions, we find that two of the sources lie a few tenths of parsecs away from different HII regions. Based on the X-ray morphology of each ULX, the velocities and distribution of the surrounding gas, as well as the location of the source in the context of the whole galaxy, we give the most

  8. Observations of galactic X-ray sources by OSO-7

    NASA Technical Reports Server (NTRS)

    Markert, T. H.; Canizares, C. R.; Clark, G. W.; Hearn, D. R.; Li, F. K.; Sprott, G. F.; Winkler, P. F.

    1977-01-01

    We present the MIT data from the OSO-7 satellite for observations of the galactic plane between 1971 and 1974. A number of sources discovered in the MIT all-sky survey are described in detail: MX 0049 + 59, MX 0836 - 42, MX 1353 - 64, MX 1406 - 61, MX 1418 - 61, MX 1709 - 40, and MX 1608 - 52 (the persistent source suggested to be associated with the X-ray burst source XB 1608 - 52). Upper limits to the X-ray emission from a number of interesting objects are also derived. General results describing all of our observations of galactic sources are presented. Specifically, we display the number-intensity diagrams, luminosity functions, and color-color diagrams for all of the sources we detected. The data are divided between disk and bulge populations, and the characteristics of the two groups are contrasted. Finally, the concept of X-ray source populations and the relationship of globular cluster sources and burst sources to the disk and bulge populations are discussed.

  9. Automatic classification of time-variable X-ray sources

    SciTech Connect

    Lo, Kitty K.; Farrell, Sean; Murphy, Tara; Gaensler, B. M.

    2014-05-01

    To maximize the discovery potential of future synoptic surveys, especially in the field of transient science, it will be necessary to use automatic classification to identify some of the astronomical sources. The data mining technique of supervised classification is suitable for this problem. Here, we present a supervised learning method to automatically classify variable X-ray sources in the Second XMM-Newton Serendipitous Source Catalog (2XMMi-DR2). Random Forest is our classifier of choice since it is one of the most accurate learning algorithms available. Our training set consists of 873 variable sources and their features are derived from time series, spectra, and other multi-wavelength contextual information. The 10 fold cross validation accuracy of the training data is ∼97% on a 7 class data set. We applied the trained classification model to 411 unknown variable 2XMM sources to produce a probabilistically classified catalog. Using the classification margin and the Random Forest derived outlier measure, we identified 12 anomalous sources, of which 2XMM J180658.7–500250 appears to be the most unusual source in the sample. Its X-ray spectra is suggestive of a ultraluminous X-ray source but its variability makes it highly unusual. Machine-learned classification and anomaly detection will facilitate scientific discoveries in the era of all-sky surveys.

  10. NuSTAR Hard X-Ray Survey of the Galactic Center Region. II. X-Ray Point Sources

    NASA Astrophysics Data System (ADS)

    Hong, JaeSub; Mori, Kaya; Hailey, Charles J.; Nynka, Melania; Zhang, Shuo; Gotthelf, Eric; Fornasini, Francesca M.; Krivonos, Roman; Bauer, Franz; Perez, Kerstin; Tomsick, John A.; Bodaghee, Arash; Chiu, Jeng-Lun; Clavel, Maïca; Stern, Daniel; Grindlay, Jonathan E.; Alexander, David M.; Aramaki, Tsuguo; Baganoff, Frederick K.; Barret, Didier; Barrière, Nicolas; Boggs, Steven E.; Canipe, Alicia M.; Christensen, Finn E.; Craig, William W.; Desai, Meera A.; Forster, Karl; Giommi, Paolo; Grefenstette, Brian W.; Harrison, Fiona A.; Hong, Dooran; Hornstrup, Allan; Kitaguchi, Takao; Koglin, Jason E.; Madsen, Kristen K.; Mao, Peter H.; Miyasaka, Hiromasa; Perri, Matteo; Pivovaroff, Michael J.; Puccetti, Simonetta; Rana, Vikram; Westergaard, Niels J.; Zhang, William W.; Zoglauer, Andreas

    2016-07-01

    We present the first survey results of hard X-ray point sources in the Galactic Center (GC) region by NuSTAR. We have discovered 70 hard (3–79 keV) X-ray point sources in a 0.6 deg{}2 region around Sgr A* with a total exposure of 1.7 Ms, and 7 sources in the Sgr B2 field with 300 ks. We identify clear Chandra counterparts for 58 NuSTAR sources and assign candidate counterparts for the remaining 19. The NuSTAR survey reaches X-ray luminosities of ˜4× and ˜8 × 10{}32 erg s{}-1 at the GC (8 kpc) in the 3–10 and 10–40 keV bands, respectively. The source list includes three persistent luminous X-ray binaries (XBs) and the likely run-away pulsar called the Cannonball. New source-detection significance maps reveal a cluster of hard (>10 keV) X-ray sources near the Sgr A diffuse complex with no clear soft X-ray counterparts. The severe extinction observed in the Chandra spectra indicates that all the NuSTAR sources are in the central bulge or are of extragalactic origin. Spectral analysis of relatively bright NuSTAR sources suggests that magnetic cataclysmic variables constitute a large fraction (>40%–60%). Both spectral analysis and logN–logS distributions of the NuSTAR sources indicate that the X-ray spectra of the NuSTAR sources should have kT > 20 keV on average for a single temperature thermal plasma model or an average photon index of Γ = 1.5–2 for a power-law model. These findings suggest that the GC X-ray source population may contain a larger fraction of XBs with high plasma temperatures than the field population.

  11. NuSTAR Hard X-Ray Survey of the Galactic Center Region. II. X-Ray Point Sources

    NASA Astrophysics Data System (ADS)

    Hong, JaeSub; Mori, Kaya; Hailey, Charles J.; Nynka, Melania; Zhang, Shuo; Gotthelf, Eric; Fornasini, Francesca M.; Krivonos, Roman; Bauer, Franz; Perez, Kerstin; Tomsick, John A.; Bodaghee, Arash; Chiu, Jeng-Lun; Clavel, Maïca; Stern, Daniel; Grindlay, Jonathan E.; Alexander, David M.; Aramaki, Tsuguo; Baganoff, Frederick K.; Barret, Didier; Barrière, Nicolas; Boggs, Steven E.; Canipe, Alicia M.; Christensen, Finn E.; Craig, William W.; Desai, Meera A.; Forster, Karl; Giommi, Paolo; Grefenstette, Brian W.; Harrison, Fiona A.; Hong, Dooran; Hornstrup, Allan; Kitaguchi, Takao; Koglin, Jason E.; Madsen, Kristen K.; Mao, Peter H.; Miyasaka, Hiromasa; Perri, Matteo; Pivovaroff, Michael J.; Puccetti, Simonetta; Rana, Vikram; Westergaard, Niels J.; Zhang, William W.; Zoglauer, Andreas

    2016-07-01

    We present the first survey results of hard X-ray point sources in the Galactic Center (GC) region by NuSTAR. We have discovered 70 hard (3–79 keV) X-ray point sources in a 0.6 deg{}2 region around Sgr A* with a total exposure of 1.7 Ms, and 7 sources in the Sgr B2 field with 300 ks. We identify clear Chandra counterparts for 58 NuSTAR sources and assign candidate counterparts for the remaining 19. The NuSTAR survey reaches X-ray luminosities of ∼4× and ∼8 × 10{}32 erg s{}-1 at the GC (8 kpc) in the 3–10 and 10–40 keV bands, respectively. The source list includes three persistent luminous X-ray binaries (XBs) and the likely run-away pulsar called the Cannonball. New source-detection significance maps reveal a cluster of hard (>10 keV) X-ray sources near the Sgr A diffuse complex with no clear soft X-ray counterparts. The severe extinction observed in the Chandra spectra indicates that all the NuSTAR sources are in the central bulge or are of extragalactic origin. Spectral analysis of relatively bright NuSTAR sources suggests that magnetic cataclysmic variables constitute a large fraction (>40%–60%). Both spectral analysis and logN–logS distributions of the NuSTAR sources indicate that the X-ray spectra of the NuSTAR sources should have kT > 20 keV on average for a single temperature thermal plasma model or an average photon index of Γ = 1.5–2 for a power-law model. These findings suggest that the GC X-ray source population may contain a larger fraction of XBs with high plasma temperatures than the field population.

  12. Image-guided microbeam irradiation to brain tumour bearing mice using a carbon nanotube X-ray source array

    PubMed Central

    Zhang, Lei; Yuan, Hong; Burk, Laurel M; Inscoe, Christy R; Hadsell, Michael J; Chtcheprov, Pavel; Lee, Yueh Z; Lu, Jianping; Chang, Sha; Zhou, Otto

    2014-01-01

    Microbeam radiation therapy (MRT) is a promising experimental and preclinical radiotherapy method for cancer treatment. Synchrotron based MRT experiments have shown that spatially fractionated microbeam radiation has the unique capability of preferentially eradicating tumour cells while sparing normal tissue in brain tumour bearing animal models. We recently demonstrated the feasibility of generating orthovoltage microbeam radiation with an adjustable microbeam width using a carbon nanotube based X-ray source array. Here we report the preliminary results from our efforts in developing an image guidance procedure for the targeted delivery of the narrow microbeams to the small tumour region in the mouse brain. Magnetic resonance imaging was used for tumour identification, and on-board X-ray radiography was used for imaging of landmarks without contrast agents. The two images were aligned using 2D rigid body image registration to determine the relative position of the tumour with respect to a landmark. The targeting accuracy and consistency were evaluated by first irradiating a group of mice inoculated with U87 human glioma brain tumours using the present protocol and then determining the locations of the microbeam radiation tracks using γ-H2AX immunofluorescence staining. The histology results showed that among 14 mice irradiated, 11 received the prescribed number of microbeams on the targeted tumour, with an average localization accuracy of 454 μm measured directly from the histology (537 μm if measured from the registered histological images). Two mice received one of the three prescribed microbeams on the tumour site. One mouse was excluded from the analysis due to tissue staining errors. PMID:24556798

  13. Image-guided microbeam irradiation to brain tumour bearing mice using a carbon nanotube x-ray source array.

    PubMed

    Zhang, Lei; Yuan, Hong; Burk, Laurel M; Inscoe, Christy R; Hadsell, Michael J; Chtcheprov, Pavel; Lee, Yueh Z; Lu, Jianping; Chang, Sha; Zhou, Otto

    2014-03-01

    Microbeam radiation therapy (MRT) is a promising experimental and preclinical radiotherapy method for cancer treatment. Synchrotron based MRT experiments have shown that spatially fractionated microbeam radiation has the unique capability of preferentially eradicating tumour cells while sparing normal tissue in brain tumour bearing animal models. We recently demonstrated the feasibility of generating orthovoltage microbeam radiation with an adjustable microbeam width using a carbon nanotube based x-ray source array. Here we report the preliminary results from our efforts in developing an image guidance procedure for the targeted delivery of the narrow microbeams to the small tumour region in the mouse brain. Magnetic resonance imaging was used for tumour identification, and on-board x-ray radiography was used for imaging of landmarks without contrast agents. The two images were aligned using 2D rigid body image registration to determine the relative position of the tumour with respect to a landmark. The targeting accuracy and consistency were evaluated by first irradiating a group of mice inoculated with U87 human glioma brain tumours using the present protocol and then determining the locations of the microbeam radiation tracks using γ-H2AX immunofluorescence staining. The histology results showed that among 14 mice irradiated, 11 received the prescribed number of microbeams on the targeted tumour, with an average localization accuracy of 454 µm measured directly from the histology (537 µm if measured from the registered histological images). Two mice received one of the three prescribed microbeams on the tumour site. One mouse was excluded from the analysis due to tissue staining errors. PMID:24556798

  14. Image-guided microbeam irradiation to brain tumour bearing mice using a carbon nanotube x-ray source array

    NASA Astrophysics Data System (ADS)

    Zhang, Lei; Yuan, Hong; Burk, Laurel M.; Inscoe, Christy R.; Hadsell, Michael J.; Chtcheprov, Pavel; Lee, Yueh Z.; Lu, Jianping; Chang, Sha; Zhou, Otto

    2014-03-01

    Microbeam radiation therapy (MRT) is a promising experimental and preclinical radiotherapy method for cancer treatment. Synchrotron based MRT experiments have shown that spatially fractionated microbeam radiation has the unique capability of preferentially eradicating tumour cells while sparing normal tissue in brain tumour bearing animal models. We recently demonstrated the feasibility of generating orthovoltage microbeam radiation with an adjustable microbeam width using a carbon nanotube based x-ray source array. Here we report the preliminary results from our efforts in developing an image guidance procedure for the targeted delivery of the narrow microbeams to the small tumour region in the mouse brain. Magnetic resonance imaging was used for tumour identification, and on-board x-ray radiography was used for imaging of landmarks without contrast agents. The two images were aligned using 2D rigid body image registration to determine the relative position of the tumour with respect to a landmark. The targeting accuracy and consistency were evaluated by first irradiating a group of mice inoculated with U87 human glioma brain tumours using the present protocol and then determining the locations of the microbeam radiation tracks using γ-H2AX immunofluorescence staining. The histology results showed that among 14 mice irradiated, 11 received the prescribed number of microbeams on the targeted tumour, with an average localization accuracy of 454 µm measured directly from the histology (537 µm if measured from the registered histological images). Two mice received one of the three prescribed microbeams on the tumour site. One mouse was excluded from the analysis due to tissue staining errors.

  15. First Search for an X-Ray-Optical Reverberation Signal in an Ultraluminous X-Ray Source

    NASA Astrophysics Data System (ADS)

    Pasham, Dheeraj R.; Strohmayer, Tod E.; Cenko, S. Bradley; Trippe, Margaret L.; Mushotzky, Richard F.; Gandhi, Poshak

    2016-02-01

    Using simultaneous optical (VLT/FORS2) and X-ray (XMM-Newton) data of NGC 5408, we present the first ever attempt to search for a reverberation signal in an ultraluminous X-ray source (NGC 5408 X-1). The idea is similar to active galactic nucleus broad line reverberation mapping where a lag measurement between the X-ray and the optical flux combined with a Keplerian velocity estimate should enable us to weigh the central compact object. We find that although NGC 5408 X-1's X-rays are variable on a timescale of a few hundred seconds (rms of 9.0 ± 0.5%), the optical emission does not show any statistically significant variations. We set a 3σ upper limit on the rms optical variability of 3.3%. The ratio of the X-ray to the optical variability is an indicator of X-ray reprocessing efficiency. In X-ray binaries, this ratio is roughly 5. Assuming a similar ratio for NGC 5408 X-1, the expected rms optical variability is ≈2%, which is still a factor of roughly two lower than what was possible with the VLT observations in this study. We find marginal evidence (3σ) for optical variability on a ˜24 hr timescale. Our results demonstrate that such measurements can be made, but photometric conditions, low sky background levels, and longer simultaneous observations will be required to reach optical variability levels similar to those of X-ray binaries.

  16. Distributed source x-ray tube technology for tomosynthesis imaging

    PubMed Central

    Sprenger, F.; Calderon-Colon, X.; Cheng, Y.; Englestad, K.; Lu, J.; Maltz, J.; Paidi, A.; Qian, X.; Spronk, D.; Sultana, S.; Yang, G.; Zhou, O.

    2011-01-01

    Tomosynthesis imaging requires projection images from different viewing angles. Conventional systems use a moving xray source to acquire the individual projections. Using a stationary distributed x-ray source with a number of sources that equals the number of required projections, this can be achieved without any mechanical motion. Advantages are a potentially faster image acquisition speed, higher spatial and temporal resolution and simple system design. We present distributed x-ray sources based on carbon nanotube (CNT) field emission cathodes. The field emission cathodes deliver the electrons required for x-ray production. CNT emitters feature a stable emission at high current density, a cold emission, excellent temporal control of the emitted electrons and good configurability. We discuss the use of stationary sources for two applications: (i) a linear tube for stationary digital breast tomosynthesis (sDBT), and (ii) a square tube for on-board tomosynthesis image-guided radiation therapy (IGRT). Results from high energy distributed sources up to 160kVp are also presented. PMID:21785671

  17. Measuring x-ray spectra of flash radiographic sources

    NASA Astrophysics Data System (ADS)

    Gehring, Amanda E.; Espy, Michelle A.; Haines, Todd J.; Mendez, Jacob; Moir, David C.; Sedillo, Robert; Shurter, Roger P.; Volegov, Petr; Webb, Timothy J.

    2015-08-01

    A Compton spectrometer has been re-commissioned for measurements of flash radiographic sources. The determination of the energy spectrum of these sources is difficult due to the high count rates and short nature of the pulses (~50 ns). The spectrometer is a 300 kg neodymium-iron magnet which measures spectra in the <1 MeV to 20 MeV energy range. Incoming x-rays are collimated into a narrow beam incident on a converter foil. The ejected Compton electrons are collimated so that the forward-directed electrons enter the magnetic field region of the spectrometer. The position of the electrons at the magnet's focal plane is a function of their momentum, allowing the x-ray spectrum to be reconstructed. Recent measurements of flash sources are presented.

  18. ELECTRON INJECTORS FOR NEXT GENERATION X-RAY SOURCES.

    SciTech Connect

    BLUEM,H.; BEN-ZVI,I.; SRINIVASAN-RAO,T.; ET AL.

    2004-08-02

    Next generation x-ray sources require very high-brightness electron beams that are typically at or beyond the present state-of-the-art, and thus place stringent and demanding requirements upon the electron injector parameters. No one electron source concept is suitable for all the diverse applications envisaged, which have operating characteristics ranging from high-average-current, quasi-CW, to high-peak-current, single-pulse electron beams. Advanced Energy Systems, in collaboration with various partners, is developing several electron injector concepts for these x-ray source applications. The performance and design characteristics of five specific RF injectors, spanning ''L'' to ''X''-band, normal-conducting to superconducting, and low repetition rate to CW, which are presently in various stages of design, construction or testing, is described. We also discuss the status and schedule of each with respect to testing.

  19. Einstein observations of extended galactic X-ray sources

    NASA Technical Reports Server (NTRS)

    Seward, F. D.

    1979-01-01

    Features of the X-ray pictures taken aboard the space observatory are presented. Imaging proportional counter pictures in three broad X-ray energy ranges were obtained. The X-ray spectrum of supernova remnants is described.

  20. X-ray Thomson Scattering using the Hybrid X-pinch X-ray Source

    NASA Astrophysics Data System (ADS)

    Hoyt, Cad; Pikuz, Sergei; Shelkovenko, Tania; Hammer, Dave

    2013-10-01

    Stringent photometric and bandwidth requirements have historically relegated X-ray Thomson scattering (XRTS) probe sources to high energy laser plasma sources or free electron lasers. Standard x-pinch configurations in which two or more fine wires cross and subtend an angle of about 30° forming an ``X'' between the anode and cathode of a pulsed power generatorcan produce extremely bright, subnanosecond bursts of continuum and line radiation from micron-scale sources. The hybrid x-pinch is a new configuration based on conical W-Cu alloy electrodes with a short 1-2 mm gap that is bridged by a fine wire resulting in an easier to load setup with improved performance characteristics. We explore the possibility of utilizing the hybid x-pinch as a novel XRTS probe source by examining certain spectral and temporal attributes of a range of materials in a hybrid x-pinch configuration on the XP (500 kA, 50 ns) and COBRA(1MA, 100ns) pulsed power generators. We find that a Ti hybrid x-pinch produces >1012 photons/sr in Ti He-alpha radiation and satisfies the noncollective scattering bandwidth requirement. Measurements of photon fluence, bandwidth and applicability to the relevant scattering regime and initial scattering results will be presented.

  1. Application of monochromatic keV X-ray source to X-ray drug delivery system

    NASA Astrophysics Data System (ADS)

    Uesaka, Mitsuru; Taguchi, Hiroki; Mori, Azusa; Yusa, Noritaka; Kato, Takamitsu; Okayasu, Ryuichi

    2009-09-01

    X-ray Drug Delivery System (DDS) enhances accumulation of anti-cancer drug or contrast agent by surrounding it with polymer and Enhanced Penetration and Retention (EPR) effect. DDS uses advanced nano-scaled polymers that contain and deliver drug or contrast agent to cancers without side effects. Several X-ray DDSs pose high-Z atoms such as gold to absorb X-rays effectively and used as contrast agent for inspection. Moreover, they have radiation enhancement effect by emission of Auger electron and successive characteristic X-rays. The enhancement factor of gold is more than five. This could be used even for therapy. This new modality must be very important for inspection and therapy of deep cancers. We are making use of our X-band Compton scattering monochromatic keV X-ray source for the inspection. Numerical simulation on monochromatic X-ray CT for possible concentration of gold-colloid DDS considering the X-ray property from the source was done. Enough visibility was confirmed. Furthermore, in vitro experiment analyzed its toxic effect to cells by the Alkaline comet assay and fluorescent immunostaining method for single and double strand breaks of DNA. Availability of clear imaging for the inspection has been confirmed by the numerical simulation and the in-vitro evaluation of the therapy effect is under way.

  2. Long-term cycles in cosmic X-ray sources

    NASA Technical Reports Server (NTRS)

    Priedhorsky, W. C.; Holt, S. S.

    1987-01-01

    Data on long-term cycles in galactic X-ray sources are reviewed, and classes of variations are identified including precessional activity, recurrent outbursts in Population II sources, and Be/neutron star flare cycles. Cycles of 30-300 days have been found in LMC X-4, Her X-1, SS433, and Cyg X-1 which represent cyclic variations in both the inner and outer parts of the accretion disk. Quasi-periodic cycles with periods ranging from 1/2 to 2 years have been noted in several low-mass X-ray binaries. It is suggested that periodic outbursts in the Be/neutron star systems may result from variable mass transfer in a wide eccentric orbit.

  3. Kinematics of Compton backscattering x-ray source for angiography

    SciTech Connect

    Blumberg, L.N.

    1992-05-01

    Calculations of X-Ray production rates, energy spread, and spectrum of Compton-backscattered photons from a Free Electron Laser on an electron beam in a low energy (136-MeV) compact (8.5-m circumference) storage ring indicate that an X-Ray intensity of 34.6 10{sup 7} X-Ray photons per 0.5-mm {times} 0.5-mm pixel for Coronary Angiography near the 33.169-keV iodine K-absorption edge can be achieved in a 4-msec pulse within a scattering cone of 1-mrad half angle. This intensity, at 10-m from the photon-electron interaction point to the patient is about a factor of 10 larger than presently achieved from a 4.5-T superconducting wiggler source in the NSLS 2.5-GeV storage ring and over an area about 5 times larger. The 2.2-keV energy spread of the Compton-backscattered beam is, however, much larger than the 70-eV spread presently attained form the wiggler source and use of a monochromator. The beam spot at the 10-m interaction point-to-patient distance is 20-mm diameter; larger spots are attainable at larger distances but with a corresponding reduction in X-Ray flux. Such a facility could be an inexpensive clinical alternative to present methods of non-invasive Digital Subtraction Angiography (DSA), small enough to be deployed in an urban medical center, and could have other medical, industrial and aerospace applications. Problems with the Compton backscattering source include laser beam heating of the mirror in the FEL oscillator optical cavity, achieving a large enough X-Ray beam spot at the patient, and obtaining radiation damping of the transverse oscillations and longitudinal emittance dilution of the storage ring electron beam resulting from photon-electron collisions without going to higher electron energy where the X-Ray energy spread becomes excessive for DSA. 38 refs.

  4. Measuring X-ray Spectra of Flash Radiographic Sources

    NASA Astrophysics Data System (ADS)

    Gehring, Amanda; Espy, Michelle; Haines, Todd; Mendez, Jacob; Moir, David; Sedillo, Robert; Volegov, Petr; Webb, Tim

    2015-10-01

    A Compton spectrometer has been re-commissioned for measurements of flash radiographic sources. The determination of the energy spectrum provides information about the x-ray production mechanisms of these sources (ie. reaction history of plasmas, electron-target interactions) and benefits the analysis of images obtained at radiographic facilities. However, the measurements of the spectra are difficult due to the high count rates and short nature of the pulses (~ 50 ns). The spectrometer is a 300 kg neodymium-iron magnet which measures spectra in the <1 MeV to 20 MeV energy range. Incoming x-rays are collimated into a narrow beam incident on a converter foil. The ejected Compton electrons are collimated so that the forward-directed electrons enter the magnetic field region of the spectrometer. The position of the electrons at the focal plane of the magnet is a function of their momentum, allowing the x-ray spectrum to be reconstructed. Recent measurements of both flash and continuous radiographic sources will be presented.

  5. Analysis of the Central X-ray Source in DG Tau

    NASA Astrophysics Data System (ADS)

    Schneider, P. Christian; Schmitt, Jürgen H. M. M.

    As a stellar X-ray source DG Tau shows two rather unusual features: A resolved X-ray jet [2] and an X-ray spectrum best described by two thermal components with different absorbing column densities, a so called "two-absorber X-ray (TAX)" morphology [1, 2]. In an effort to understand the properties of the central X-ray source in DG Tau a detailed position analysis was carried out.

  6. Optically thick X-ray transfer - The shell game. [transmission through gas surrounding cosmic x ray source

    NASA Technical Reports Server (NTRS)

    Langer, S. H.; Ross, R. R.; Mccray, R.

    1978-01-01

    This paper investigates the radiative transfer of X-rays through a shell that is optically thick to Compton scattering, surrounding a point source of continuum X-rays. The emission and absorption of X-rays due to K-shell transitions of iron are included. The calculations are done in two entirely independent ways: by Monte Carlo simulation and by solving a Fokker-Planck diffusion equation. The emergent spectra agree very well for Thomson depths of at least about 2. The validity is confirmed of the modification to the Fokker-Planck equation of Kompaneets (1957) that is required when the photon energy is large compared with the average thermal energy of the electrons. A procedure is also developed for treating models of compact X-ray sources consisting of incomplete shells.

  7. Ultraluminous X-ray sources - three exciting years

    NASA Astrophysics Data System (ADS)

    Bachetti, M.

    2015-09-01

    Ultraluminous X-ray sources are off-nuclear extragalactic sources with (apparent) luminosities exceeding the Eddington limit for a stellar-mass black hole. This naturally suggests an association with the elusive class of intermediate-mass black holes, or with super-Eddington accreting black holes. As it turns out, this peculiar class of sources is actually a variegated zoo, including both classes of accreting black holes mentioned above and, rather unexpectedly, neutron stars. In this talk I will overview the astrophysical properties of these objects, and give an update on the many breakthroughs appeared in the literature in the last three years.

  8. X-ray sources in Galactic old Open Star Clusters

    NASA Astrophysics Data System (ADS)

    van den Berg, M.

    2013-01-01

    I review the current status of studies of the X-ray sources in Galactic old open clusters. Cataclysmic variables (CVs), magnetically-active binaries (ABs), and sub-subgiants (SSGs) dominate the X-ray emission of old open clusters. Surprisingly, the number of ABs detected inside the half-mass radius with LX ≥ 1 × 1030 erg s-1 (0.3-7 keV) does not appear to scale with cluster mass. Comparison of the numbers of CVs, ABs, and SSGs per unit mass in old open and globular clusters shows that each of these classes is under-abundant in globulars. This suggests that dense environments suppress the frequency of even some of the hardest binaries.

  9. The Brookhaven Superconducting X-Ray Lithography Source (SXLS)

    SciTech Connect

    Murphy, J.B.; Blumberg, L.N.; Bozoki, E.; Desmond, E.; Galayda, J.; Halama, H.; Heese, R.; Hsieh, H.; Keane, J.; Kramer, S.; Mortazavi, P.; Schuchman, J.; Sharma, S.; Singh, O.; Solomon, L.; Thomas, M.; Wang, J.M. ); Kalsi, S.; Reusch, M.; Rose, J. ); Moser, H.O. )

    1990-01-01

    Synchrotron radiation from dipole magnets in electron storage rings has emerged as a useful source of x-rays for lithography. The goal of the SXLS Project at BNL is to design and construct a compact storage ring of circumference, C = 8.503 meters. It will use superconducting dipoles with a field of B{sub 0} = 3.87 Tesla and bending radius of {rho} = .6037 meters along with 700 MeV electrons to produce 10 angstrom x-rays for lithography. The project is proceeding in two phases: in Phase I low field iron dipoles are being used; in Phase II the low field dipoles will be replaced with superconducting dipoles. An overview of the design and status report are presented.

  10. Searches for correlated X-ray and radio emission from X-ray burst sources

    NASA Technical Reports Server (NTRS)

    Johnson, H. M.; Catura, R. C.; Lamb, P. A.; White, N. E.; Sanford, P. W.; Hoffman, J. A.; Lewin, W. H. G.; Jernigan, J. G.

    1978-01-01

    The NRAO Green Bank interferometer has been used to monitor MXB 1730-335 and MXB 1837+05 during periods when 68 X-ray bursts were detected by X-ray observations. No significant radio emission was detected from these objects, or from MXB 1820-30 and MXB 1906+00, which emitted no bursts throughout the simultaneous observations. The data place upper limits on radio emission from these objects in the 2695 and 8085 MHz bands.

  11. Note: Construction of x-ray scattering and x-ray absorption fine structure beamline at the Pohang Light Source

    SciTech Connect

    Lee, Ik-Jae; Yu, Chung-Jong; Yun, Young-Duck; Lee, Chae-Soon; Seo, In Deuk; Kim, Hyo-Yun; Lee, Woul-Woo; Chae, Keun Hwa

    2010-02-15

    A new hard x-ray beamline, 10B KIST-PAL beamline (BL10B), has been designed and constructed at the Pohang Light Source (PLS) in Korea. The beamline, operated by Pohang Accelerator Laboratory-Korean Institute of Science and Technology consortium, is dedicated to x-ray scattering (XRS) and x-ray absorption fine structure (XAFS) experiments. X rays with photon energies from 4.0 to 16.0 keV are delivered to the experimental station passing a collimating mirror, a fixed-exit double-crystal Si(111) monochromator, and a toroidal mirror. Basic experimental equipments for XAFS measurement, a high resolution diffractometry, an image plate detector system, and a hot stage have been prepared for the station. From our initial commissioning and performance testing of the beamline, it is observed that BL10B beamline can perform XRS and XAFS measurements successfully.

  12. Simultaneous X-ray and optical observations of the flaring X-ray source, Aquila A-1

    NASA Technical Reports Server (NTRS)

    Bowyer, C. S.; Charles, P. A.

    1979-01-01

    During the summer of 1978 the recurrent transient X-ray source, Aquila X-1, underwent its first major outburst in two years. The results of extensive observations at X-ray and optical wavelengths throughout this event, which lasted for approximately two months are presented. The peak X-ray luminosity was approximately 1.3 times that of the Crab and exhibited spectral dependent flickering on timescales approximately 5 minutes. The observations are interpreted in terms of a standard accretion disk model withparticular emphasis on the similarities to Sco X-1 and other dward X-ray systems, although the transient nature of the system remains unexplained. It was found that Aquila X-1 can be described adequately by the semi-detached Roche lobe model and yields a mass ratio of less than or approximate to 3.5.

  13. An extended galactic population of low-luminosity x-ray sources (CVs?) and the diffuse x-ray background

    NASA Technical Reports Server (NTRS)

    Maoz, Eyal; Grindlay, Jonathan E.

    1995-01-01

    The incompatibility of the properties of the X-ray background (XRB) with active galactic nuclei (AGNs) contributing approximately greater than 60% at energies of a few keV has often been interpreted as being due to a substantial contribution of a new population of yet unrecognized X-ray sources. The existence of such population has been recently suggested also by an analysis of very deep ROSAT observations which revealed a considerable excess of faint X-ray sources over that expected from QSO evolution models, and that the average spectrum of the resolved sources becomes harder with decreasing flux limit. These sources could be extragalactic in origin, but if they make a substantial contribution to the XRB then they must exhibit much weaker clustering than galaxies or QSOs in order to be consistent with the stringent constraints on source clustering imposed by autocorrelation analyses of the unresolved XRB. We investigate the possibility that the indicated new population of X-ray sources is Galactic in origin. Examining spherical halo and thick disk distributions, we derive the allowed properties of such populations which would resolve the discrepancy found in the number counts of faint sources and be consistent with observational constraints on the total background intensity, the XRB anisotropy, the number of unidentified bright sources, the Galaxy's total X-ray luminosity, and with the results of fluctuation analyses of the unresolved XRB. We find that a flattened Galactic halo (or a thick disk) distribution with a scale height of a few kpc is consistent with all the above requirements. The typical X-ray luminosity of the sources is approximately equal to 10(exp 30-31)ergs/s in the 0.5-2 keV band, the number density of sources in the solar vicinity is approximately 10(exp -4.5)pc(exp -3), their total number in the Galaxy is approximately 10(exp 8.5), and their total contribution to the Galaxy's X-ray luminosity is approximately 10(exp 39) ergs/s. We discuss the

  14. A 6 second periodic X-ray source in Carina

    NASA Technical Reports Server (NTRS)

    Seward, F. D.; Charles, P. A.; Smale, A. P.

    1986-01-01

    A serendipitous source, 1E 1048.1-5937, was discovered during Einstein imaging observations of the Carina nebula. On July 13, 1979, this source had an intensity of 0.14 IPC counts/s, and the signal was 65 percent pulsed with a period of 6.44 s. An earlier observation failed to detect any source with strength greater than 1/10 the above signal. The source is therefore highly variable, perhaps transient. An Exosat observation of this source on June 20, 1985 confirmed the pulse period and refined the source position to an accuracy of 10 arcsec. On the basis of the position, the source is tentatively identified with a V = 19 optical counterpart. The X-ray spectrum is best fitted by a power law with photon index = 2.26 and a column density of 1.6 x 10 to the 22nd atoms/sq cm. The X-ray characteristics are consistent with an accretion-powered Be star binary.

  15. Deterministic Chaos in the X-ray Sources

    NASA Astrophysics Data System (ADS)

    Grzedzielski, M.; Sukova, P.; Janiuk, A.

    2015-12-01

    Hardly any of the observed black hole accretion disks in X-ray binaries and active galaxies shows constant flux. When the local stochastic variations of the disk occur at specific regions where a resonant behaviour takes place, there appear the quasi-periodic oscillations (QPOs). If the global structure of the flow and its non-linear hydrodynamics affects the fluctuations, the variability is chaotic in the sense of deterministic chaos. Our aim is to solve a problem of the stochastic versus deterministic nature of the black hole binary variabilities. We use both observational and analytic methods. We use the recurrence analysis and we study the occurence of long diagonal lines in the recurrence plot of observed data series and compare it to the surrogate series. We analyze here the data of two X-ray binaries - XTE J1550-564 and GX 339-4 observed by Rossi X-ray Timing Explorer. In these sources, the non-linear variability is expected because of the global conditions (such as the mean accretion rate) leading to the possible instability of an accretion disk. The thermal-viscous instability and fluctuations around the fixed-point solution occurs at high accretion rate, when the radiation pressure gives dominant contribution to the stress tensor.

  16. Properties and Applications of Laser Generated X-Ray Sources

    SciTech Connect

    Smith, R F; Key, M H

    2002-02-25

    The rapid development of laser technology and related progress in research using lasers is shifting the boundaries where laser based sources are preferred over other light sources particularly in the XUV and x-ray spectral region. Laser based sources have exceptional capability for short pulse and high brightness and with improvements in high repetition rate pulsed operation, such sources are also becoming more interesting for their average power capability. This study presents an evaluation of the current capabilities and near term future potential of laser based light sources and summarizes, for the purpose of comparison, the characteristics and near term prospects of sources based on synchrotron radiation and free electron lasers. Conclusions are drawn on areas where the development of laser based sources is most promising and competitive in terms of applications potential.

  17. Near-infrared spectroscopy of faint discrete X-ray point sources constituting the Galactic ridge X-ray emission

    NASA Astrophysics Data System (ADS)

    Morihana, Kumiko; Tsujimoto, Masahiro; Dubath, Pierre; Yoshida, Tessei; Suzuki, Kensuke; Ebisawa, Ken

    2016-05-01

    The Galactic Ridge X-ray Emission (GRXE) is an apparently extended X-ray emission along the Galactic plane. The X-ray spectrum is characterized by a hard continuum with a strong Fe K emission feature in the 6-7 keV band. A substantial fraction (˜80%) of the GRXE in the Fe band was resolved into point sources by deep Chandra imaging observations; thus GRXE is mostly composed of dim Galactic X-ray point sources, at least in this energy band. To investigate the populations of these dim X-ray point sources, we carried out near-infrared (NIR) follow-up spectroscopic observations in two deep Chandra fields located in the Galactic plane at (l, b) = (0.1°, -1.4°) and (28.5°, 0.0°) using NTT/SofI and Subaru/MOIRCS. We obtained well-exposed NIR spectra from 65 objects and found that there are three main classes of Galactic sources based on the X-ray color and NIR spectral features: those having (A) hard X-ray spectra and NIR emission features such as H I (Brγ), He I, and He II (2 objects), (B) soft X-ray spectra and NIR absorption features such as H I, Na I, Ca I, and CO (46 objects), and (C) hard X-ray spectra and NIR absorption features such as H I, Na I, Ca I, and CO (17 objects). From these features, we argue that class A sources are cataclysmic variables (CVs), and class B sources are late-type stars with enhanced coronal activity, which is in agreement with current knowledge. Class C sources possibly belong to a new group of objects, which has been poorly studied so far. We argue that the candidate sources for class C are the binary systems hosting white dwarfs and late-type companions with very low accretion rates. It is likely that this newly recognized class of sources contribute to a non-negligible fraction of the GRXE, especially in the Fe K band.

  18. Near-infrared spectroscopy of faint discrete X-ray point sources constituting the Galactic ridge X-ray emission

    NASA Astrophysics Data System (ADS)

    Morihana, Kumiko; Tsujimoto, Masahiro; Dubath, Pierre; Yoshida, Tessei; Suzuki, Kensuke; Ebisawa, Ken

    2016-08-01

    The Galactic Ridge X-ray Emission (GRXE) is an apparently extended X-ray emission along the Galactic plane. The X-ray spectrum is characterized by a hard continuum with a strong Fe K emission feature in the 6-7 keV band. A substantial fraction (˜80%) of the GRXE in the Fe band was resolved into point sources by deep Chandra imaging observations; thus GRXE is mostly composed of dim Galactic X-ray point sources, at least in this energy band. To investigate the populations of these dim X-ray point sources, we carried out near-infrared (NIR) follow-up spectroscopic observations in two deep Chandra fields located in the Galactic plane at (l, b) = (0.1°, -1.4°) and (28.5°, 0.0°) using NTT/SofI and Subaru/MOIRCS. We obtained well-exposed NIR spectra from 65 objects and found that there are three main classes of Galactic sources based on the X-ray color and NIR spectral features: those having (A) hard X-ray spectra and NIR emission features such as H I (Brγ), He I, and He II (2 objects), (B) soft X-ray spectra and NIR absorption features such as H I, Na I, Ca I, and CO (46 objects), and (C) hard X-ray spectra and NIR absorption features such as H I, Na I, Ca I, and CO (17 objects). From these features, we argue that class A sources are cataclysmic variables (CVs), and class B sources are late-type stars with enhanced coronal activity, which is in agreement with current knowledge. Class C sources possibly belong to a new group of objects, which has been poorly studied so far. We argue that the candidate sources for class C are the binary systems hosting white dwarfs and late-type companions with very low accretion rates. It is likely that this newly recognized class of sources contribute to a non-negligible fraction of the GRXE, especially in the Fe K band.

  19. Uhuru observations of 4U 1608-52 - The 'steady' X-ray source associated with the X-ray burst source in Norma

    NASA Technical Reports Server (NTRS)

    Tananbaum, H.; Chaisson, L. J.; Forman, W.; Jones, C.; Matilsky, T. A.

    1976-01-01

    Data are presented for the X-ray source 4U 1608-52, summarizing its light curve, location, and spectral parameters. Evidence is presented showing that this source is the 'steady' X-ray counterpart of the X-ray burst source in Norma. The spectrum of the 'steady' source is compared with the spectrum observed during two bursts, and it is noted that there is substantially more low-energy absorption during the bursts. The 'steady' source spectral data are used to examine the optical data, and it is concluded that if the X-ray spectrum is thermal, then a globular-cluster counterpart probably would have been detected (whereas none has been). Further X-ray and optical observations are suggested for this source, since an optical identification may be central in determining whether all X-ray bursts have a common origin and if this origin requires a globular-cluster environment.

  20. Discovery of multiple low-luminosity X-ray sources in NGC 6397

    NASA Technical Reports Server (NTRS)

    Cool, Adrienne M.; Grindlay, Jonathan E.; Krockenberger, Martin; Bailyn, Charles D.

    1993-01-01

    New low-luminosity X-ray sources have been discovered in NGC 6397 with the ROSAT High Resolution Imager. These sources have a total number, spatial distribution, and X-ray luminosities consistent with their being CVs. The findings supports the hypothesis that the low-luminosity X-ray sources in clusters are generally dominated by CVs.

  1. Observations of X-ray Sources with the Chandra X-ray Observatory

    NASA Astrophysics Data System (ADS)

    Garmire, Gordon

    2000-04-01

    The Chandra X-ray Observatory (CXO) offers unprecedented angular resolution and sensitivity compared to previous or currently flying X-ray Missions. Results of a number of observations conducted during the previous six months of operation will be presented. Some of the observations include very long exposures toward the Hubble Deep Field North, the supernova remnants 1987A, RCW103, and N103B, the Orion Nebula, the Galactic Center, M82 and a survey of low luminosity Active Galactic Nuclei. This work is a collaboration between scientists at Penn State University, MIT and Caltech. The support for this endeavor comes from NASA through contract NAS8-38252.

  2. The Lack of Halo Ultraluminous X-Ray Sources

    NASA Technical Reports Server (NTRS)

    Swartz, Douglas A.

    2006-01-01

    The premise that Ultraluminous X-ray sources (ULXs) exist beyond the optical extent of nearby galaxies is investigated. A published catalog containing 41 ULX candidates located between 1 and approx. 3 times the standard D-{25} isophotal radius of their putative host galaxies is examined. Twenty-one of these sources have spectroscopically-confirmed distances. All 21 are background objects giving a 95\\% probability that at least 37 of the 41 candidates are background sources. Thirty-nine of the 41 sources have X-ray-to-optical flux ratios, -1.61.6.) The uniform spatial distribution of the sample is also consistent with a background population. This evidence suggests that ULXs rarely, if at all, exist beyond the distribution of luminous matter in nearby galaxies and, as a consequence, there is no correlation between the population of ULXs and halo objects such as old globular clusters or Population III remnants.

  3. X-ray micrography and imaging of Escherichia coli cell shape using laser plasma pulsed point x-ray sources.

    PubMed Central

    Rajyaguru, J M; Kado, M; Richardson, M C; Muszynski, M J

    1997-01-01

    High-resolution x-ray microscopy is a relatively new technique and is performed mostly at a few large synchrotron x-ray sources that use exposure times of seconds. We utilized a bench-top source of single-shot laser (ns) plasma to generate x-rays similar to synchrotron facilities. A 5 microlitres suspension of Escherichia coli ATCC 25922 in 0.9% phosphate buffered saline was placed on polymethylmethyacrylate coated photoresist, covered with a thin (100 nm) SiN window and positioned in a vacuum chamber close to the x-ray source. The emission spectrum was tuned for optimal absorption by carbon-rich material. Atomic force microscope scans provided a surface and topographical image of differential x-ray absorption corresponding to specimen properties. By using this technique we observed a distinct layer around whole cells, possibly representing the Gram-negative envelope, darker stained areas inside the cell corresponding to chromosomal DNA as seen by thin section electron microscopy, and dent(s) midway through one cell, and 1/3- and 2/3-lengths in another cell, possibly representing one or more division septa. This quick and high resolution with depth-of-field microscopy technique is unmatched to image live hydrated ultrastructure, and has much potential for application in the study of fragile biological specimens. Images FIGURE 2 FIGURE 3 FIGURE 4 FIGURE 5 FIGURE 6 PMID:9083658

  4. Constraints on hot star X-ray source characteristics from combinded analysis of X-ray and UV observations

    NASA Technical Reports Server (NTRS)

    Macfarlane, J. J.

    1994-01-01

    Results from wind ionization calculations are presented which show how the P-Cygni profiles of 'superionized' species such as O VI can provide information about the X-ray source characteristics of early-type stars. Using detailed radiative and atomic physics models, we find that a significant source of X-ray emission from zeta Pup comes from a region in the wind located within rougly 1 to 2 stellar radii of the photosphere. Our results suggest that X-rays sources in which emission occurs exclusively at large radii (r greater than or approximately equal to a few R(sub *)) are inconsistent with UV P-Cygni profiles for O VI. Instead, we find that X-ray emission from shocks distributed throughout the lower regions of the wind (r approximately equal to 1-2 R(sub *)) is consistent with both X-ray and UV data, as well as mass loss rates deduced from radio and H-alpha observations.

  5. The faint X-ray sources in and out of omega Centauri: X-ray observations and optical identifications

    NASA Technical Reports Server (NTRS)

    Cool, Adrienne M.; Grindlay, Jonathan E.; Bailyn, Charles D.; Callanan, Paul J.; Hertz, Paul

    1995-01-01

    We present the results of an observation of the globular cluster omega Cen (NGC 5139) with the Einstein high-resolution imager (HRI). Of the five low-luminosity X-ray sources toward omega Cen which were first identified with the Einstein imaging proportional counter (IPC) (Hertz and Grindlay 1983a, b), two are detected in the Einstein HRI observation: IPC sources A and D. These detections provide source positions accurate to 3 sec-4 sec; the positions are confirmed in a ROSAT HRI observation reported here. Using CCD photometry and spectroscopy, we have identified both sources as foreground dwarf M stars with emission lines (dMe). The chance projection of two Mde stars within approximately 13 min of the center of omega Cen is not extraordinary, given the space density of these stellar coronal X-ray sources. We discuss the possible nature of the three as yet unidentified IPC sources toward omega Cen, and consider the constraints that the Einstein observations place on the total population of X-ray sources in this cluster. The integrated luminosity from faint X-ray sources in omega Cen appears to be low relative to both the old open cluster M67 and the post-core-collapse globular, NGC 6397.

  6. Flat Field Anomalies in an X-ray CCD Camera Measured Using a Manson X-ray Source

    SciTech Connect

    M. J. Haugh and M. B. Schneider

    2008-10-31

    The Static X-ray Imager (SXI) is a diagnostic used at the National Ignition Facility (NIF) to measure the position of the X-rays produced by lasers hitting a gold foil target. The intensity distribution taken by the SXI camera during a NIF shot is used to determine how accurately NIF can aim laser beams. This is critical to proper NIF operation. Imagers are located at the top and the bottom of the NIF target chamber. The CCD chip is an X-ray sensitive silicon sensor, with a large format array (2k x 2k), 24 μm square pixels, and 15 μm thick. A multi-anode Manson X-ray source, operating up to 10kV and 10W, was used to characterize and calibrate the imagers. The output beam is heavily filtered to narrow the spectral beam width, giving a typical resolution E/ΔE≈10. The X-ray beam intensity was measured using an absolute photodiode that has accuracy better than 1% up to the Si K edge and better than 5% at higher energies. The X-ray beam provides full CCD illumination and is flat, within ±1% maximum to minimum. The spectral efficiency was measured at 10 energy bands ranging from 930 eV to 8470 eV. We observed an energy dependent pixel sensitivity variation that showed continuous change over a large portion of the CCD. The maximum sensitivity variation occurred at 8470 eV. The geometric pattern did not change at lower energies, but the maximum contrast decreased and was not observable below 4 keV. We were also able to observe debris, damage, and surface defects on the CCD chip. The Manson source is a powerful tool for characterizing the imaging errors of an X-ray CCD imager. These errors are quite different from those found in a visible CCD imager.

  7. X-ray generation using carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Parmee, Richard J.; Collins, Clare M.; Milne, William I.; Cole, Matthew T.

    2015-01-01

    Since the discovery of X-rays over a century ago the techniques applied to the engineering of X-ray sources have remained relatively unchanged. From the inception of thermionic electron sources, which, due to simplicity of fabrication, remain central to almost all X-ray applications, there have been few fundamental technological advances. However, with the emergence of ever more demanding medical and inspection techniques, including computed tomography and tomosynthesis, security inspection, high throughput manufacturing and radiotherapy, has resulted in a considerable level of interest in the development of new fabrication methods. The use of conventional thermionic sources is limited by their slow temporal response and large physical size. In response, field electron emission has emerged as a promising alternative means of deriving a highly controllable electron beam of a well-defined distribution. When coupled to the burgeoning field of nanomaterials, and in particular, carbon nanotubes, such systems present a unique technological opportunity. This review provides a summary of the current state-of-the-art in carbon nanotube-based field emission X-ray sources. We detail the various fabrication techniques and functional advantages associated with their use, including the ability to produce ever smaller electron beam assembles, shaped cathodes, enhanced temporal stability and emergent fast-switching pulsed sources. We conclude with an overview of some of the commercial progress made towards the realisation of an innovative and disruptive technology.

  8. SPECTRAL STATES AND EVOLUTION OF ULTRALUMINOUS X-RAY SOURCES

    SciTech Connect

    Feng Hua; Kaaret, Philip

    2009-05-10

    We examined spectral evolution in ultraluminous X-ray sources (ULXs) with apparent luminosities of about 10{sup 40} erg s{sup -1}. Based on new results in this paper, and those reported in the literature, two common spectral behaviors were found. Some ULXs in starburst galaxies have varying luminosity (L) but remain in the hard state with power-law spectra and a constant, hard photon index ({gamma}). Other ULXs, such as NGC 5204 X-1, show a correlation between L and {gamma}. We interpret this L-{gamma} correlated phase as an intermediate state with hybrid properties from the thermal dominant and steep power-law states. When the spectra of NGC 5204 X-1 are fitted with a multicolor disk blackbody plus power-law model, the X-ray luminosity increases with the effective temperature of the accretion disk in a manner similar to that found in stellar-mass black hole X-ray binaries, suggesting that the emission arises from an accretion disk. The luminosity, disk size, and temperature suggest that NGC 5204 X-1 harbors a compact object more massive than stellar-mass black holes. In contrast, the disk model in IC 342 X-1 is ruled out because the luminosity decreases as the temperature increases; sources with such behavior may represent a class of objects with super-Eddington accretion. Also, we report a peculiar soft spectral feature from IC 342 X-2 and variability on a timescale of 20 ks from Holmberg II X-1. More observations are needed to test these results.

  9. EFFECT OF SATELLITE LINES FROM X-RAY SOURCE ON X-RAY DIFFRACTION PEAKS

    EPA Science Inventory

    The article discusses the development of a method for relating reactivity to crystallite size and strain parameters obtained by the Warren-Averbach technique. PA has been using crystallite size and strain data obtained from x-ray diffraction (XRD) peak profile analysis to predict...

  10. The HEAO A-1 X-ray source catalog

    NASA Technical Reports Server (NTRS)

    Wood, K. S.; Meekins, J. F.; Yentis, D. J.; Smathers, H. W.; Mcnutt, D. P.; Bleach, R. D.; Friedman, H.; Byram, E. T.; Chubb, T. A.; Meidav, M.

    1984-01-01

    The catalog of X-ray sources detected during the NRL Large Area Sky Survey (LASS) with the HEAO 1 satellite is presented. The catalog is derived from the first six months of data from HEAO 1 and includes sources detected during one full scan. Positions and intensities for a total of 842 different sources are included, with a limiting flux of 250 nJy at 5 keV. The catalog is more than 90 percent complete at a flux level equivalent to 1.5 microjoules at 5 keV for a Crab-like spectrum. Cross-references with published literature are provided and coincidental identifications are proposed for some of the sources which have been never studied before. A cross-sectional line drawing of the sensor module of HEAO I is also provided.

  11. Formation and evolution of luminous supersoft X-ray sources

    NASA Technical Reports Server (NTRS)

    Rappaport, S.; Di Stefano, R.; Smith, J. D.

    1994-01-01

    Luminous supersoft X-ray sources, with characteristic luminosities of approximately 10(exp 38) ergs/s and temperatures, kT, of approximately 35 eV, have been established as a new and distinct class of X-ray source through recent Roentgen Satellite (ROSAT) observations. Several possible physical models have been proposed for these sources. One promising scenario (van den Heuvel et al. 1992) involves mass transfer, which is unstable on a thermal timescale, from a main-sequence or subgiant donor star onto the surface of a white dwarf. For a narrow range of accretion rates, steady nuclear burning of the accreted matter can take place. This process can provide the high luminosities and the correct range of temperatures observed in the supersoft sources. However, given the limited range of mass transfer rates that are consistent with this phenomenon, it is far from obvious that a sufficient population of such systems exists in galaxies such as our own, M31, and the Magellanic Clouds, in order to account for the large number of supersoft sources which can be inferred from present observations. This work addresses the population question in detail, through a Monte Carlo simulation of the formation and evolution of such systems, which starts with zero-age primordial binaries. In order to evolve into close binary systems which contain a white dwarf component and a companion transferring mass at a rate within the requisite narrow range, a binary system must undergo a specific progression of evolutionary steps. We find that a sufficient subset of our initial binaries evolve to become systems with the requisite properties, so that they can account for the population of supersoft sources that is inferred from observations. In particular, we find that there should be more than 1000 systems in the Galaxy today with properties that very closely match those of the observed supersoft sources. From our models, we find expected luminosities, white dwarf effective temperatures, and

  12. X-ray reverberations and the giant X-ray bursts. [short duration pulse in plasma cloud surrounding X-ray source

    NASA Technical Reports Server (NTRS)

    Canizares, C. R.

    1976-01-01

    It is shown that the shape and spectral evolution of the giant X-ray bursts from the source 3U 1820-30 can be explained by Compton scattering of a short, intense X-ray pulse in a cloud surrounding the source. Pulse shapes due to Thomson scattering of an X-ray burst in an electron cloud were calculated for the (1) optically thin case on the assumption of one scattering per photon, (2) intermediate case with optical depth of about unity, and (3) optically thick case where the process is regarded as diffusion of photons through a uniform sphere. For the intermediate case, the effects of the reverberation were determined explicitly by Monte Carlo calculation. For an optical depth of 3, square pulse duration of 2 sec, characteristic cloud radius of 70,000 km, characteristic cloud density of 4 times 10 to the 14th per cu cm, and temperature of 5-30 keV, the calculations give a reasonably accurate description of X-ray bursts from 3U 1820-30. The scattering model does not imply the existence of a supermassive, central black hole.

  13. Final Report: Rotating anode x-ray source, January 1, 1996 - April 30, 1998

    SciTech Connect

    Falco, Charles M.

    1998-04-30

    The 18 KW Rigaku high brilliance rotating anode X-ray source with four-circle qoniometer is used for X-ray diffraction characterization on thin films. This X-ray source can determine the crystal structures of a wide variety of thin materials of the type used in the semiconductor and magnetic data storage industries.

  14. Survey for Radio Nebulae Around Ultraluminous X-ray Sources

    NASA Astrophysics Data System (ADS)

    Miller, Neal A.; Heil, Martha Nicole; Mushotzky, Richard

    2016-01-01

    The nature of ultraluminous X-ray sources (ULX) is an ongoing debate. As such sources appear to violate the Eddington Limit for the expected masses of stellar remnants, ULX may represent a class of super-Eddington objects, "intermediate" mass black holes (IMBH) emitting at sub-Eddington levels, or a diverse population including examples of both. Most initial efforts to search for radio emission associated with ULX did so with high angular resolution in hopes of applying the "fundamental plane of black hole activity" which relates X-ray luminosity, radio luminosity, and black hole mass. The predicted radio flux densities for such compact radio emission are quite low meaning that even non-detections leave open much of the mass range associated with IMBH. However, a small number of ULX have been associated with extended radio emission and these radio nebulae have sizes and energetics that differentiate them from more common classes of extended objects such as HII regions and supernova remnants. We report here on the results of a cohesive study to identify and characterize ULX radio nebula associated with unbiased samples of ULX. This study has two prongs: one relying upon archival Very Large Array data and one using new, dedicated Jansky Very Large Array observations. Several new candidate ULX radio nebulae are identified and characterized, and along with limits from non-detections we discuss implications for the overall population of ULX.

  15. Population of post-nova supersoft X-ray sources

    NASA Astrophysics Data System (ADS)

    Soraisam, Monika D.; Gilfanov, Marat; Wolf, William M.; Bildsten, Lars

    2016-01-01

    Novae undergo a supersoft X-ray phase of varying duration after the optical outburst. Such transient post-nova supersoft X-ray sources (SSSs) are the majority of the observed SSSs in M31. In this paper, we use the post-nova evolutionary models of Wolf et al. to compute the expected population of post-nova SSSs in M31. We predict that depending on the assumptions about the white dwarf (WD) mass distribution in novae, at any instant there are about 250-600 post-nova SSSs in M31 with (unabsorbed) 0.2-1.0 keV luminosity Lx ≥ 1036 erg s-1. Their combined unabsorbed luminosity is of the order of ˜1039 erg s-1. Their luminosity distribution shows significant steepening around log (Lx) ˜ 37.7-38 and becomes zero at Lx ≈ 2 × 1038 erg s-1, the maximum Lx achieved in the post-nova evolutionary tracks. Their effective temperature distribution has a roughly power-law shape with differential slope of ≈4-6 up to the maximum temperature of Teff ≈ 1.5 × 106 K. We compare our predictions with the results of the XMM-Newton monitoring of the central field of M31 between 2006 and 2009. The predicted number of post-nova SSSs exceeds the observed number by a factor of ≈2-5, depending on the assumed WD mass distribution in novae. This is good agreement, considering the number and magnitude of uncertainties involved in calculations of the post-nova evolutionary models and their X-ray output. Furthermore, only a moderate circumstellar absorption, with hydrogen column density of the order of ˜1021 cm-2, will remove the discrepancy.

  16. 26.3 MHz radio source survey. III - Correlation with extragalactic X-ray sources

    NASA Technical Reports Server (NTRS)

    Erickson, W. C.; Matthews, T. A.; Viner, M. R.

    1978-01-01

    The correlation between extragalactic X-ray sources and radio sources in a 26.3-MHz catalog is studied. A list of reliably identified sources is developed by examining X-ray, optical, and radio data for those candidate objects that are in or near the X-ray error boxes. The source 3UR 0432+05 is identified with 3C 120, 3UR 1555+27 (identified with A2142) is shown to be a steep-spectrum radio source, and it is found that 86% of the high-galactic-latitude sources can be reliably identified when the X-ray source error areas are no more than 1 sq deg. The results also indicate that: (1) X-ray sources identified with clusters of galaxies as a whole, with individual galaxies in clusters, and with separate isolated galaxies have similar decametric properties in that their spectral indices and radio luminosities fall in the same range; (2) there is a Bautz-Morgan dependence of both the X-ray and the decametric luminosities of clusters and of individual objects in clusters; and (3) the X-ray luminosity of all except compact sources appears to be approximately proportional to the decametric luminosity.

  17. LIGHT SOURCE: Spot size diagnostics for flash radiographic X-ray sources at LAPA

    NASA Astrophysics Data System (ADS)

    Li, Cheng-Gang; Li, Qin; Shi, Jin-Shui; Deng, Jian-Jun

    2009-06-01

    Spot size is one of the parameters to characterize the performance of a radiographic X-ray source. It determines the degree of blurring due to magnification directly. In recent years, a variety of measurement methods have been used to diagnose X-ray spot size at Laboratory of Accelerator Physics and Application (LAPA). Computer simulations and experiments showed that using a rolled-edge to measure the spot size are more accurate, and the intensity distribution of X-ray source was obtained by a device with a square aperture. Experimental and simulation results on a flash X-ray source at our laboratory are presented and discussed in this paper. In addition, a new method for time resolved diagnostics of X-ray spot size is introduced too.

  18. High Brightness, Laser-Driven X-ray Source for Nanoscale Metrology and Femtosecond Dynamics

    SciTech Connect

    Siders, C W; Crane, J K; Semenov, V; Betts, S; Kozioziemski, B; Wharton, K; Wilks, S; Barbee, T; Stuart, B; Kim, D E; An, J; Barty, C

    2007-02-26

    This project developed and demonstrated a new, bright, ultrafast x-ray source based upon laser-driven K-alpha generation, which can produce an x-ray flux 10 to 100 times greater than current microfocus x-ray tubes. The short-pulse (sub-picosecond) duration of this x-ray source also makes it ideal for observing time-resolved dynamics of atomic motion in solids and thin films.

  19. Modification of the TASMIP x-ray spectral model for the simulation of microfocus x-ray sources

    SciTech Connect

    Sisniega, A.; Vaquero, J. J.; Desco, M.

    2014-01-15

    Purpose: The availability of accurate and simple models for the estimation of x-ray spectra is of great importance for system simulation, optimization, or inclusion of photon energy information into data processing. There is a variety of publicly available tools for estimation of x-ray spectra in radiology and mammography. However, most of these models cannot be used directly for modeling microfocus x-ray sources due to differences in inherent filtration, energy range and/or anode material. For this reason the authors propose in this work a new model for the simulation of microfocus spectra based on existing models for mammography and radiology, modified to compensate for the effects of inherent filtration and energy range. Methods: The authors used the radiology and mammography versions of an existing empirical model [tungsten anode spectral model interpolating polynomials (TASMIP)] as the basis of the microfocus model. First, the authors estimated the inherent filtration included in the radiology model by comparing the shape of the spectra with spectra from the mammography model. Afterwards, the authors built a unified spectra dataset by combining both models and, finally, they estimated the parameters of the new version of TASMIP for microfocus sources by calibrating against experimental exposure data from a microfocus x-ray source. The model was validated by comparing estimated and experimental exposure and attenuation data for different attenuating materials and x-ray beam peak energy values, using two different x-ray tubes. Results: Inherent filtration for the radiology spectra from TASMIP was found to be equivalent to 1.68 mm Al, as compared to spectra obtained from the mammography model. To match the experimentally measured exposure data the combined dataset required to apply a negative filtration of about 0.21 mm Al and an anode roughness of 0.003 mm W. The validation of the model against real acquired data showed errors in exposure and attenuation in

  20. Irregular X-ray variability in the transient X-ray burst source MXB 1659-29

    NASA Technical Reports Server (NTRS)

    Cominsky, L.; Ossmann, W.; Lewin, W. H. G.

    1983-01-01

    Irregular variability in the X-ray emission from MXB 1659-29 was observed with SAS 3 during the 1978 transient outburst of the source. No stable period can yet be derived from the low-intensity states, although there is evidence for a quasi-periodicity of either 1.2 or 1.4 hours. The low-intensity states observed in MXB 1659-29 during the transient outburst vary both in width and duration, similar to those in MXB 1916-05. The SAS 3 data are consistent with either the intermittent obscuration of the X-ray emitter by relatively cold gas or with scattering of the X-rays by hotter material.

  1. Novae as a Class of Transient X-ray Sources

    NASA Technical Reports Server (NTRS)

    Mukai, K.; Orio, M.; Valle, M. Della

    2007-01-01

    Motivated by the recently discovered class of faint (10(exp 34)-10(exp 35) ergs/s) X-ray transients in the Galactic Center region, we investigate the 2-10 keV properties of classical and recurrent novae. Existing data are consistent with the idea that all classical novae are transient X-ray sources with durations of months to years and peak luminosities in the 10(exp 34)-10(exp 35)ergs/s range. This makes classical novae a viable candidate class for the faint Galactic Center transients. We estimate the rate of classical novae within a 15 arcmin radius region centered on the Galactic Center (roughly the field of view of XMM-Newton observations centered on Sgr A*) to be approx.0.1 per year. Therefore, it is plausible that some of the Galactic Center transients that have been announced to date are unrecognized classical novae. The continuing monitoring of the Galactic Center region carried out by Chandra and XMM-Newton may therefore provide a new method to detect classical novae in this crowded and obscured region, an

  2. Chilled disks in ultraluminous X-ray sources

    NASA Astrophysics Data System (ADS)

    Soria, Roberto; Kuncic, Zdenka; Gonçalves, Anabela C.

    2007-04-01

    The "soft-excess" component fitted to the X-ray spectra of many ultraluminous X-ray sources (ULXs) remains a controversial finding, which may reveal fundamental information either on the black hole (BH) mass or on the state of the accretion flow. In the simplest model, it was explained as thermal emission from a cool accretion disk around an intermediate-mass BH (about 1000 solar masses). We argue that this scenario is highly implausible, and discuss and compare the two most likely alternatives. 1) The soft-excess does come from a cool disk; however, the temperature is low not because of a high BH mass but because most of the accretion power is drained from the inner disk via magnetic torques, and channelled into jets and outflows ("chilled disk" scenario). Using a phenomenological model, we infer that ULXs contain BHs of about 50 solar masses accreting gas at about 10 times their Eddington rate. 2) The soft excess is in fact a soft deficit, if the power-law continuum is properly fitted. Such broad absorption features are caused by smeared absorption lines in fast, highly ionized outflows. This scenario has already been successfully applied to the soft excess in AGN. If so, this spectral feature reveals details of disk outflows,but is unrelated to the BH mass.

  3. Soft x-ray contact imaging of biological specimens using a laser-produced plasma as an x-ray source

    SciTech Connect

    Cheng, P.C.

    1990-01-01

    The use of a laser-produced plasma as an x-ray source provides significant advantages over other types of sources for x-ray microradiography of, particularly, living biological specimens. The pulsed nature of the x-rays enables imaging of the specimen in a living state, and the small source size minimizes penumbral blurring. This makes it possible to make an exposure close to the source, thereby increasing the x-ray intensity. In this article, we will demonstrate the applications of x-ray contact microradiography in structural and developmental botany such as the localization of silica deposition and the floral morphologenesis of maize.

  4. X-ray detectors at the Linac Coherent Light Source

    PubMed Central

    Blaj, Gabriel; Caragiulo, Pietro; Carini, Gabriella; Carron, Sebastian; Dragone, Angelo; Freytag, Dietrich; Haller, Gunther; Hart, Philip; Hasi, Jasmine; Herbst, Ryan; Herrmann, Sven; Kenney, Chris; Markovic, Bojan; Nishimura, Kurtis; Osier, Shawn; Pines, Jack; Reese, Benjamin; Segal, Julie; Tomada, Astrid; Weaver, Matt

    2015-01-01

    Free-electron lasers (FELs) present new challenges for camera development compared with conventional light sources. At SLAC a variety of technologies are being used to match the demands of the Linac Coherent Light Source (LCLS) and to support a wide range of scientific applications. In this paper an overview of X-ray detector design requirements at FELs is presented and the various cameras in use at SLAC are described for the benefit of users planning experiments or analysts looking at data. Features and operation of the CSPAD camera, which is currently deployed at LCLS, are discussed, and the ePix family, a new generation of cameras under development at SLAC, is introduced. PMID:25931071

  5. X-ray detectors at the Linac Coherent Light Source

    DOE PAGESBeta

    Blaj, Gabriel; Caragiulo, Pietro; Carini, Gabriella; Carron, Sebastian; Dragone, Angelo; Freytag, Dietrich; Haller, Gunther; Hart, Philip; Hasi, Jasmine; Herbst, Ryan; et al

    2015-04-21

    Free-electron lasers (FELs) present new challenges for camera development compared with conventional light sources. At SLAC a variety of technologies are being used to match the demands of the Linac Coherent Light Source (LCLS) and to support a wide range of scientific applications. In this paper an overview of X-ray detector design requirements at FELs is presented and the various cameras in use at SLAC are described for the benefit of users planning experiments or analysts looking at data. Features and operation of the CSPAD camera, which is currently deployed at LCLS, are discussed, and the ePix family, a newmore » generation of cameras under development at SLAC, is introduced.« less

  6. X-ray detectors at the Linac Coherent Light Source

    SciTech Connect

    Blaj, Gabriel; Caragiulo, Pietro; Carini, Gabriella; Carron, Sebastian; Dragone, Angelo; Freytag, Dietrich; Haller, Gunther; Hart, Philip; Hasi, Jasmine; Herbst, Ryan; Herrmann, Sven; Kenney, Chris; Markovic, Bojan; Nishimura, Kurtis; Osier, Shawn; Pines, Jack; Reese, Benjamin; Segal, Julie; Tomada, Astrid; Weaver, Matt

    2015-04-21

    Free-electron lasers (FELs) present new challenges for camera development compared with conventional light sources. At SLAC a variety of technologies are being used to match the demands of the Linac Coherent Light Source (LCLS) and to support a wide range of scientific applications. In this paper an overview of X-ray detector design requirements at FELs is presented and the various cameras in use at SLAC are described for the benefit of users planning experiments or analysts looking at data. Features and operation of the CSPAD camera, which is currently deployed at LCLS, are discussed, and the ePix family, a new generation of cameras under development at SLAC, is introduced.

  7. Refractive lenses for coherent x-ray sources.

    PubMed

    Pantell, R H; Feinstein, J; Beguiristain, H R; Piestrup, M A; Gary, C K; Cremer, J T

    2001-10-01

    Incoherent x rays in the wavelength interval from approximately 0.5-2 A have been focused with refractive lenses. A single lens would have a long focal length because the refractive index of any material is close to unity; but with a stack of N lens elements the focal length is reduced by the factor N, and such a lens is termed a compound refractive lens (CRL). Misalignment of the parabolic lens elements does not alter the focusing properties and results in only a small reduction in transmission. Based on the principle of spontaneous emission amplification in a FEL wiggler, coherent x-ray sources are being developed with wavelengths of 1-1.5 A and source diameters of 50-80 mum; and the CRL can be used to provide a small, intense image. Chromatic aberration increases the image size by an amount comparable with the diffraction-limited size, and so chromatic correction is important. Pulse broadening through the lens that is due to material dispersion is negligible. The performance of a CRL used in conjunction with a coherent source is analyzed by means of the Kirchhoff integral. For typical parameters, intensity gain is 10(5)-10(6), where gain is defined as the intensity ratio in an image plane with and without the lens in place. (There may be some confusion concerning the usage of the word intensity. As employed in this manuscript, intensity, also called irradiance, refers to power per unit area. This is a commonly accepted usage for intensity, although there are places in the literature where the term radiant incidence is reserved for this definition and intensity refers to power per unit solid angle.) The image intensity is maximized when the CRL is placed 100-200 m from the source, and the diameter of the diffraction-limited spot is approximately 0.12 mum. PMID:18364790

  8. Flash X-Ray (FXR) Accelerator Optimization Electronic Time-Resolved Measurement of X-Ray Source Size

    SciTech Connect

    Jacob, J; Ong, M; Wargo, P

    2005-07-21

    Lawrence Livermore National Laboratory (LLNL) is currently investigating various approaches to minimize the x-ray source size on the Flash X-Ray (FXR) linear induction accelerator in order to improve x-ray flux and increase resolution for hydrodynamic radiography experiments. In order to effectively gauge improvements to final x-ray source size, a fast, robust, and accurate system for measuring the spot size is required. Timely feedback on x-ray source size allows new and improved accelerator tunes to be deployed and optimized within the limited run-time constraints of a production facility with a busy experimental schedule; in addition, time-resolved measurement capability allows the investigation of not only the time-averaged source size, but also the evolution of the source size, centroid position, and x-ray dose throughout the 70 ns beam pulse. Combined with time-resolved measurements of electron beam parameters such as emittance, energy, and current, key limiting factors can be identified, modeled, and optimized for the best possible spot size. Roll-bar techniques are a widely used method for x-ray source size measurement, and have been the method of choice at FXR for many years. A thick bar of tungsten or other dense metal with a sharp edge is inserted into the path of the x-ray beam so as to heavily attenuate the lower half of the beam, resulting in a half-light, half-dark image as seen downstream of the roll-bar; by measuring the width of the transition from light to dark across the edge of the roll-bar, the source size can be deduced. For many years, film has been the imaging medium of choice for roll-bar measurements thanks to its high resolution, linear response, and excellent contrast ratio. Film measurements, however, are fairly cumbersome and require considerable setup and analysis time; moreover, with the continuing trend towards all-electronic measurement systems, film is becoming increasingly difficult and expensive to procure. Here, we shall

  9. Synchrotron x-ray sources and new opportunities in the soil and environmental sciences

    SciTech Connect

    Schulze, D. ); Anderson, S. ); Mattigod, S. )

    1990-07-01

    This report contains the following papers: characteristics of the advanced photon source and comparison with existing synchrotron facilities; x-ray absorption spectroscopy: EXAFS and XANES -- A versatile tool to study the atomic and electronic structure of materials; applications of x-ray spectroscopy and anomalous scattering experiments in the soil and environmental sciences; X-ray fluorescence microprobe and microtomography.

  10. An active M star with X-ray double flares disguised as an ultra-luminous X-ray source

    NASA Astrophysics Data System (ADS)

    Guo, Jin-Cheng; Liu, Ji-Feng; Wang, Song; Wu, Yue; Qin, Yu-Xiang

    2016-02-01

    Here we present research on an ultra-luminous X-ray source (ULX) candidate 2XMM J140229.91+542118.8. The X-ray light curves of this ULX candidate in M101 exhibit features of a flare star. More importantly, the Chandra light curve displays unusual X-ray double flares, which is comprised of two close peaks. The X-ray (0.3-11.0 keV) flux of the first peak was derived from the two-temperature APEC model as ˜ 1.1 ± 0.1 × 10-12 erg cm-2 s-1. The observed flux at its first peak increased by about two orders of magnitude in X-ray as compared to quiescence. The slope of the second fast decay phase is steeper than the slope of the first fast decay phase, indicating that the appearance of a second flare accelerated the cooling of the first flare in a way we do not understand yet. We also observed its optical counterpart using a 2.16 m telescope administered by National Astronomical Observatories, Chinese Academy of Sciences. By optical spectral fitting, it is confirmed to be a late type dMe2.5 star. According to the spectral type and apparent magnitude of its optical counterpart, we estimate the photometric distance to be ˜ 133.4 ± 14.2 pc. According to the X-ray spectral fitting, a possible explanation is provided. However, more similar close double flares are needed to confirm whether this accelerated cooling event is a unique coincidence or a common physical process during double flaring.

  11. Observation of Organelles in Leydig Cells by Contact Soft X-Ray Microscopy with a Laser Plasma X-Ray Source

    NASA Astrophysics Data System (ADS)

    Kado, M.; Ishino, M.; Tamotsu, S.; Yasuda, K.; Kishimoto, M.; Nishikino, M.; Kinjo, Y.; Shinohara, K.

    2011-09-01

    We observed the same biological specimens for comparison of the images by contact soft x-ray microscopy with a laser plasma x-ray source with those by confocal laser microscopy. Images of wet Leydig cells were directly comparable for organelles and showed that actin filaments and mitochondria were clearly identified in the soft x-ray images.

  12. A rapid noninvasive characterization of CT x-ray sources

    SciTech Connect

    Randazzo, Matt; Tambasco, Mauro

    2015-07-15

    Purpose: The aim of this study is to generate spatially varying half value layers (HVLs) that can be used to construct virtual equivalent source models of computed tomography (CT) x-ray sources for use in Monte Carlo CT dose computations. Methods: To measure the spatially varying HVLs, the authors combined a cylindrical HVL measurement technique with the characterization of bowtie filter relative attenuation (COBRA) geometry. An apparatus given the name “HVL Jig” was fabricated to accurately position a real-time dosimeter off-isocenter while surrounded by concentric cylindrical aluminum filters (CAFs). In this geometry, each projection of the rotating x-ray tube is filtered by an identical amount of high-purity (type 1100 H-14) aluminum while the stationary radiation dose probe records an air kerma rate versus time waveform. The CAFs were progressively nested to acquire exposure data at increasing filtrations to calculate the HVL. Using this dose waveform and known setup geometry, each timestamp was related to its corresponding fan angle. Data were acquired using axial CT protocols (i.e., rotating tube and stationary patient table) at energies of 80, 100, and 120 kVp on a single CT scanner. These measurements were validated against the more laborious conventional step-and-shoot approach (stationary x-ray tube). Results: At each energy, HVL data points from the COBRA-cylinder technique were fit to a trendline and compared with the conventional approach. The average relative difference in HVL between the two techniques was 1.3%. There was a systematic overestimation in HVL due to scatter contamination. Conclusions: The described method is a novel, rapid, accurate, and noninvasive approach that allows one to acquire the spatially varying fluence and HVL data using a single experimental setup in a minimum of three scans. These measurements can be used to characterize the CT beam in terms of the angle-dependent fluence and energy spectra along the bowtie filter

  13. Soft x-ray undulator for the Siam Photon Source

    SciTech Connect

    Rugmai, S.; Dasri, T.; Prawanta, S.; Siriwattanapaitoon, S.; Kwankasem, A.; Sooksrimuang, V.; Chachai, W.; Suradet, N.; Juthong, N.; Tancharakorn, S.

    2007-01-19

    An undulator for production of intense soft x-rays has been designed for the Siam Photon Source. The construction of the undulator has been completed. It is now being characterized and prepared for installation. The device, named U60, is a pure permanent magnet planar undulator, consisting of 41 magnetic periods, with 60 mm period length. Utilization of the undulator radiation in the photon energy range of 30 - 900 eV is expected. The design studies of the magnetic structure, including investigation of perturbations arising from the magnetic field of the device, their effects on the SPS storage ring and compensation schemes are described. A magnetic measurement system has been constructed for magnetic characterization of the device. Partial results of magnetic measurements are presented.

  14. X-ray lithography source (SXLS) vacuum system

    SciTech Connect

    Schuchman, J.C.; Aloia, J.; Hsieh, H.; Kim, T.; Pjerov, S.

    1989-01-01

    In 1988 Brookhaven National Laboratory (BNL) was awarded a contract to design and construct a compact light source for x-ray lithography. This award is part of a technology transfer-to-American-industry program. The contract is for an electron storage ring designed for 690 MeV-500 ma operations. It has a racetrack configuration with a circumference to 8.5 meters. The machine is to be constructed in two phases. Phase I (200 MeV-500ma) will primarily be for low energy injection studies and will incorporate all room temperature magnets. For Phase II the two room temperature dipole magnets will be replaced with (4T) superconducting magnets and operation will be at 690 MeV. This paper describes the vacuum system for this machine. 9 refs.

  15. Soft x-ray resist characterization: Studies with a laser plasma x-ray source

    SciTech Connect

    Kubiak, G.D.; Outka, D.A. ); Zeigler, J.M. )

    1990-01-01

    Little work has been performed to characterize the exposure sensitivity, contrast, and tone of candidate resists for photon energies between 100--300 eV, the range in which projection soft x-ray lithography will be developed. We report here the characterization of near-edge x-ray absorption fine structure (NEXAFS) spectra, exposure sensitivity, contrast, and post-exposure processing of selected polysilane resists at photon energies close to the Si L{sub 2,3} absorption edge (100 eV). We find absorption resonance features in the NEXAFS spectra which we assign to excitation into Si--Si and Si--C {sigma}* orbitals. Using monochromatized XUV exposures on the Si--Si {sigma}* resonance at 105 eV, followed by solvent dissolution development, we have measured the exposure sensitivity curves of these resists. We find sensitivities in the range of 600--3000 mJ/cm{sup 2} and contrasts in the range from 0.5--1.4, depending on the polysilane side chain. We have also performed exposure sensitivity measurements at 92 eV, below the edge. Sensitivity decreases slightly compared to 105 eV exposures and the saturation depth and contrast both increase, as expected. We find also that exposing resist films to oxygen after XUV exposure, but before development increases the sensitivity markedly. 7 figs.

  16. Search for scattered X-ray halos around variable sources - The X-ray halo of Cygnus X-1

    NASA Technical Reports Server (NTRS)

    Bode, M. F.; Priedhorsky, W. C.; Norwell, G. A.; Evans, A.

    1985-01-01

    The results of a program to search for the presence of halos due to X-ray scattering by interstellar grains in the line-of-sight to variable X-ray sources are reported. As part of this program, four Einstein HRI images of Cyg X-1 were examined. The analysis technique exploits the intrinsic aperiodic variability of this source to map the point response function of the optics. Any scattered halo present will not reflect short-term central source time variability, since such variability is smoothed by differential time delays of order days. Thus, a residual, nonvariable component to the surface brightness distribution (comprising about 12 percent or more of the source flux) is interpreted as a scattered halo. The Cyg X-1 halo is consistent with those of other sources found in previous studies using different techniques. Comparison is also made with a scattering model and, despite uncertainties in source spectrum and distance, reasonable agreement with the observatons is found using a standard interstellar grain model. The potential of X-ray scattering as a probe of the properties of interstellar grains is demonstrated.

  17. OPTICAL COUNTERPARTS OF THE NEAREST ULTRALUMINOUS X-RAY SOURCES

    SciTech Connect

    Gladstone, Jeanette C.; Heinke, Craig O.; Cartwright, Taylor F.; Copperwheat, Chris; Roberts, Timothy P.; Levan, Andrew J.; Goad, Mike R.

    2013-06-01

    We present a photometric survey of the optical counterparts of ultraluminous X-ray sources (ULXs) observed with the Hubble Space Telescope (HST) in nearby ({approx}<5 Mpc) galaxies. Of the 33 ULXs with HST and Chandra data, 9 have no visible counterpart, placing limits on their M{sub V} of {approx} -4 to -9, enabling us to rule out O-type companions in 4 cases. The refined positions of two ULXs place them in the nucleus of their host galaxy. They are removed from our sample. Of the 22 remaining ULXs, 13 have one possible optical counterpart, while multiple are visible within the error regions of other ULXs. By calculating the number of chance coincidences, we estimate that 13 {+-} 5 are the true counterparts. We attempt to constrain the nature of the companions by fitting the spectral energy distribution and M{sub V} to obtain candidate spectral types. We can rule out O-type companions in 20 cases, while we find that one ULX (NGC 253 ULX2) excludes all OB-type companions. Fitting with X-ray irradiated models provides constraints on the donor star mass and radius. For seven ULXs, we are able to impose inclination-dependent upper and/or lower limits on the black holes' mass, if the extinction to the assumed companion star is not larger than the Galactic column. These are NGC 55 ULX1, NGC 253 ULX1, NGC 253 ULX2, NGC 253 XMM6, Ho IX X-1, IC342 X-1, and NGC 5204 X-1. This suggests that 10 ULXs do not have O companions, while none of the 18 fitted rule out B-type companions.

  18. Electron cyclotron resonance ion source plasma characterization by X-ray spectroscopy and X-ray imaging.

    PubMed

    Mascali, David; Castro, Giuseppe; Biri, Sándor; Rácz, Richárd; Pálinkás, József; Caliri, Claudia; Celona, Luigi; Neri, Lorenzo; Romano, Francesco Paolo; Torrisi, Giuseppe; Gammino, Santo

    2016-02-01

    An experimental campaign aiming to investigate electron cyclotron resonance (ECR) plasma X-ray emission has been recently carried out at the ECRISs-Electron Cyclotron Resonance Ion Sources laboratory of Atomki based on a collaboration between the Debrecen and Catania ECR teams. In a first series, the X-ray spectroscopy was performed through silicon drift detectors and high purity germanium detectors, characterizing the volumetric plasma emission. The on-purpose developed collimation system was suitable for direct plasma density evaluation, performed "on-line" during beam extraction and charge state distribution characterization. A campaign for correlating the plasma density and temperature with the output charge states and the beam intensity for different pumping wave frequencies, different magnetic field profiles, and single-gas/gas-mixing configurations was carried out. The results reveal a surprisingly very good agreement between warm-electron density fluctuations, output beam currents, and the calculated electromagnetic modal density of the plasma chamber. A charge-coupled device camera coupled to a small pin-hole allowing X-ray imaging was installed and numerous X-ray photos were taken in order to study the peculiarities of the ECRIS plasma structure. PMID:26931918

  19. Electron cyclotron resonance ion source plasma characterization by X-ray spectroscopy and X-ray imaging

    NASA Astrophysics Data System (ADS)

    Mascali, David; Castro, Giuseppe; Biri, Sándor; Rácz, Richárd; Pálinkás, József; Caliri, Claudia; Celona, Luigi; Neri, Lorenzo; Romano, Francesco Paolo; Torrisi, Giuseppe; Gammino, Santo

    2016-02-01

    An experimental campaign aiming to investigate electron cyclotron resonance (ECR) plasma X-ray emission has been recently carried out at the ECRISs—Electron Cyclotron Resonance Ion Sources laboratory of Atomki based on a collaboration between the Debrecen and Catania ECR teams. In a first series, the X-ray spectroscopy was performed through silicon drift detectors and high purity germanium detectors, characterizing the volumetric plasma emission. The on-purpose developed collimation system was suitable for direct plasma density evaluation, performed "on-line" during beam extraction and charge state distribution characterization. A campaign for correlating the plasma density and temperature with the output charge states and the beam intensity for different pumping wave frequencies, different magnetic field profiles, and single-gas/gas-mixing configurations was carried out. The results reveal a surprisingly very good agreement between warm-electron density fluctuations, output beam currents, and the calculated electromagnetic modal density of the plasma chamber. A charge-coupled device camera coupled to a small pin-hole allowing X-ray imaging was installed and numerous X-ray photos were taken in order to study the peculiarities of the ECRIS plasma structure.

  20. Flat Field Anomalies in an X-Ray CCD Camera Measured Using a Manson X-Ray Source

    SciTech Connect

    Michael Haugh

    2008-03-01

    The Static X-ray Imager (SXI) is a diagnostic used at the National Ignition Facility (NIF) to measure the position of the X-rays produced by lasers hitting a gold foil target. It determines how accurately NIF can point the laser beams and is critical to proper NIF operation. Imagers are located at the top and the bottom of the NIF target chamber. The CCD chip is an X-ray sensitive silicon sensor, with a large format array (2k x 2k), 24 μm square pixels, and 15 μm thick. A multi-anode Manson X-ray source, operating up to 10kV and 2mA, was used to characterize and calibrate the imagers. The output beam is heavily filtered to narrow the spectral beam width, giving a typical resolution E/ΔE≈12. The X-ray beam intensity was measured using an absolute photodiode that has accuracy better than 1% up to the Si K edge and better than 5% at higher energies. The X-ray beam provides full CCD illumination and is flat, within ±1.5% maximum to minimum. The spectral efficiency was measured at 10 energy bands ranging from 930 eV to 8470 eV. The efficiency pattern follows the properties of Si. The maximum quantum efficiency is 0.71. We observed an energy dependent pixel sensitivity variation that showed continuous change over a large portion of the CCD. The maximum sensitivity variation was >8% at 8470 eV. The geometric pattern did not change at lower energies, but the maximum contrast decreased and was less than the measurement uncertainty below 4 keV. We were also able to observe debris on the CCD chip. The debris showed maximum contrast at the lowest energy used, 930 eV, and disappeared by 4 keV. The Manson source is a powerful tool for characterizing the imaging errors of an X-ray CCD imager. These errors are quite different from those found in a visible CCD imager.

  1. The light curve of a transient X-ray source

    NASA Technical Reports Server (NTRS)

    Kaluzienski, L. J.; Holt, S. S.; Boldt, E. A.; Serlemitsos, P. J.; Eadie, G.; Pounds, K. A.; Ricketts, M. J.; Watson, M.

    1975-01-01

    The Ariel-5 satellite has monitored the X-ray light curve of A1524-62 almost continuously from 40 days prior to maximum light until its disappearance below the effective experimental sensitivity. The source exhibited maximum light on Dec. 4, 1974, at a level of 0.9 the apparent magnitude of the Crab Nebula in the energy band 3-6 keV. Although similar to previously reported transient sources with a decay time constant of about 2 months, the source exhibited an extended, variable preflare on-state of about 1 month at a level of greater than 0.1 maximum light. The four bright (greater than 0.2 of the Crab Nebula) transient sources observed during the first half-year of Ariel-5 operation are indicative of a galactic disk distribution, a luminosity at maximum in excess of 10 to the 37-th power ergs/sec, a frequency of occurrence which may be as high as 100/yr, and a median decay time which is less than 1 month.

  2. Radio search for the pulsing X-ray source in Hercules.

    NASA Technical Reports Server (NTRS)

    Doxsey, R.; Rappaport, S.; Spencer, J.; Zaumen, W.; Murthy, G. T.

    1972-01-01

    The region of the celestial sphere near the pulsing X-ray source in Hercules (2U 1705+34) has been searched for radio emission with the NRAO three-element interferometer. The search was conducted during a period when the Hercules source was in its 27-day state of low X-ray luminosity. Four weak radio sources, which may be considered as candidates for the radio counterpart of this X-ray source, were detected.

  3. Ultraluminous X-ray sources: Three exciting years

    NASA Astrophysics Data System (ADS)

    Bachetti, M.

    2016-05-01

    The extreme extragalactic sources known as Ultraluminous X-ray Sources (ULX) represent a unique testing environment for compact objects population studies and the accretion process. Their nature has long been disputed. Their luminosity, well above the Eddington luminosity for a stellar-mass black hole, can imply the presence of an intermediate-mass black hole or a stellar black hole accreting above the Eddington limit. Both these interpretations are important to understand better the accretion process and the evolution of massive black holes. The last few years have seen a dramatic improvement of our knowledge of these sources. In particular, the super-Eddington interpretation for the bulk of the ULX population has gained a strong consensus. Nonetheless, exceptions to this general trend do exist, and in particular one ULX was shown to be a neutron star, and another was shown to be a very likely IMBH candidate. In this paper, I will review the most relevant results in this field of research in the last few years.

  4. LIGHT SOURCE: A simulation study of Tsinghua Thomson scattering X-ray source

    NASA Astrophysics Data System (ADS)

    Tang, Chuan-Xiang; Li, Ren-Kai; Huang, Wen-Hui; Chen, Huai-Bi; Du, Ying-Chao; Du, Qiang; Du, Tai-Bin; He, Xiao-Zhong; Hua, Jian-Fei; Lin, Yu-Zhen; Qian, Hou-Jun; Shi, Jia-Ru; Xiang, Dao; Yan, Li-Xin; Yu, Pei-Cheng

    2009-06-01

    Thomson scattering X-ray sources are compact and affordable facilities that produce short duration, high brightness X-ray pulses enabling new experimental capacities in ultra-fast science studies, and also medical and industrial applications. Such a facility has been built at the Accelerator Laboratory of Tsinghua University, and upgrade is in progress. In this paper, we present a proposed layout of the upgrade with design parameters by simulation, aiming at high X-ray pulses flux and brightness, and also enabling advanced dynamics studies and applications of the electron beam. Design and construction status of main subsystems are also presented.

  5. Combined optic system based on polycapillary X-ray optics and single-bounce monocapillary optics for focusing X-rays from a conventional laboratory X-ray source

    NASA Astrophysics Data System (ADS)

    Sun, Xuepeng; Liu, Zhiguo; Sun, Tianxi; Yi, Longtao; Sun, Weiyuan; Li, Fangzuo; Jiang, Bowen; Ma, Yongzhong; Ding, Xunliang

    2015-12-01

    Two combined optic systems based on polycapillary X-ray optics and single-bounce monocapillary optics (SBMO) were designed for focusing the X-rays from a conventional laboratory X-ray source. One was based on a polycapillary focusing X-ray lens (PFXRL) and a single-bounce ellipsoidal capillary (SBEC), in which the output focal spot with the size of tens of micrometers of the PFXRL was used as the "virtual" X-ray source for the SBEC. The other system was based on a polycapillary parallel X-ray lens (PPXRL) and a single-bounce parabolic capillary (SBPC), in which the PPXRL transformed the divergent X-ray beam from an X-ray source into a quasi-parallel X-ray beam with the divergence of sever milliradians as the incident illumination of the SBPC. The experiment results showed that the combined optic systems based on PFXRL and SBEC with a Mo rotating anode X-ray generator with the focal spot with a diameter of 300 μm could obtain a focal spot with the total gain of 14,300 and focal spot size of 37.4 μm, and the combined optic systems based on PPXRL and SBPC with the same X-ray source mentioned above could acquire a focal spot with the total gain of 580 and focal spot size of 58.3 μm, respectively. The two combined optic systems have potential applications in micro X-ray diffraction, micro X-ray fluorescence, micro X-ray absorption near edge structure, full field X-ray microscopes and so on.

  6. Observation of soft X-rays from extended sources. [such as Perseus star cluster

    NASA Technical Reports Server (NTRS)

    Catura, R. C.; Acton, L. W.

    1974-01-01

    Efforts were directed toward surveying several supernova remnants for the emission of soft X-rays. Rather than attempt to detect such faint X-ray emission, the program was redirected to observe the spectrum and angular structure of the extended X-ray source in the Perseus cluster of galaxies and the super-nova remnant Puppis A. An attempt was made to detect X-ray line emission from Puppis A with a Bragg crystal spectrometer. Observations provide evidence for the presence of X-ray line emission in the spectrum of Puppis A near .65 keV.

  7. In-line phase-contrast imaging based on Tsinghua Thomson scattering x-ray source.

    PubMed

    Zhang, Zhen; Du, Yingchao; Yan, Lixin; Hua, Jianfei; Yang, Jin; Xiao, Yongshun; Huang, Wenhui; Chen, Huaibi; Tang, Chuanxiang

    2014-08-01

    Thomson scattering x-ray sources can produce ultrashort, energy tunable x-ray pulses characterized by high brightness, quasi-monochromatic, and high spatial coherence, which make it an ideal source for in-line phase-contrast imaging. We demonstrate the capacity of in-line phase-contrast imaging based on Tsinghua Thomson scattering X-ray source. Clear edge enhancement effect has been observed in the experiment. PMID:25173262

  8. X-ray QPOs from the Ultra-luminous X-ray Source in M82: Evidence Against Beaming

    NASA Technical Reports Server (NTRS)

    Strohmayer, Tod E.; Mushotzky, Richard F.

    2003-01-01

    We report the discovery with the European Photon Imaging Camera (EPIC) CCD cameras onboard XMM-Newton of a 54 mHz quasiperiodic oscillation (QPO) in the greater than 2 keV X-ray flux from the ultra-luminous X-ray source (ULX) X41.4+60 in the starburst galaxy M82. This is the first detection of a QPO in the X-ray flux from an extra-Galactic ULX, and confirms that the source is a compact object. The QPO is detected in the combined PN and MOS data at the approx. 6sigma level, and separately at lower significances in both the PN and MOS instruments. It had a centroid frequency of 54.3 +/- 0.9 mHz, a coherence Q is identical with nu(sub 0)/Delta nu(sub fwhm) is approx. 5, and an amplitude (rms) in the 2 - 10 keV band of 8.5%. Below about 0.2 Hz the power spectrum can be described by a power-law with index approx. 1, and integrated amplitude (rms) of 13.5%. The X-ray spectrum requires a curving continuum, with a disk-blackbody (diskbb) at T = 3.1 keV providing an acceptable, but not unique, fit. A broad Fe line centered at 6.55 keV is required in all fits, but the equivalent width (EW) of the line is sensitive to the choice of continuum model. There is no evidence of a reflection component. The implied bolometric luminosity is approx. 4 - 5 x 10(exp 40) ergs/s. Data from several archival Rossi X-ray Timing Explorer (RXTE) pointings at M82 also show evidence for QPOs in the 50 - 100 mHz frequency range. Several Galactic black hole candidates (BHCs), including GRS 1915+105, GRO J1655-40, and XTE 1550-564, show QPOs in the same frequency range as the 50 - 100 mHz QPOs in X41.4+60, which at first glance suggests a possible connection with such objects. However, strong, narrow QPOs provide solid evidence for disk emission, and thus present enormous theoretical difficulties for models which rely on either geometrically or relativistically beamed emission to account for the high X-ray luminosities. We discuss the implications of our findings for models of the ULX sources.

  9. Special issue on compact x-ray sources

    NASA Astrophysics Data System (ADS)

    Hooker, Simon; Midorikawa, Katsumi; Rosenzweig, James

    2014-04-01

    Journal of Physics B: Atomic, Molecular and Optical Physics is delighted to announce a forthcoming special issue on compact x-ray sources, to appear in the winter of 2014, and invites you to submit a paper. The potential for high-brilliance x- and gamma-ray sources driven by advanced, compact accelerators has gained increasing attention in recent years. These novel sources—sometimes dubbed 'fifth generation sources'—will build on the revolutionary advance of the x-ray free-electron laser (FEL). New radiation sources of this type have widespread applications, including in ultra-fast imaging, diagnostic and therapeutic medicine, and studies of matter under extreme conditions. Rapid advances in compact accelerators and in FEL techniques make this an opportune moment to consider the opportunities which could be realized by bringing these two fields together. Further, the successful development of compact radiation sources driven by compact accelerators will be a significant milestone on the road to the development of high-gradient colliders able to operate at the frontiers of particle physics. Thus the time is right to publish a peer-reviewed collection of contributions concerning the state-of-the-art in: advanced and novel acceleration techniques; sophisticated physics at the frontier of FELs; and the underlying and enabling techniques of high brightness electron beam physics. Interdisciplinary research connecting two or more of these fields is also increasingly represented, as exemplified by entirely new concepts such as plasma based electron beam sources, and coherent imaging with fs-class electron beams. We hope that in producing this special edition of Journal of Physics B: Atomic, Molecular and Optical Physics (iopscience.iop.org/0953-4075/) we may help further a challenging mission and ongoing intellectual adventure: the harnessing of newly emergent, compact advanced accelerators to the creation of new, agile light sources with unprecedented capabilities

  10. Spectral variability of ultraluminous X-ray sources

    SciTech Connect

    Kajava, Jari J. E.; Poutanen, Juri

    2008-09-30

    We study spectral variability of 11 ultraluminous X-ray sources (ULX) using archived XMM-Newton and Chandra observations. We use three models to describe the observed spectra; a power-law, a multi-colour disk (MCD) and a combination of these two models. We find that out of the 11 ULXs in our sample, 7 ULXs show a correlation between the luminosity and the photon index {gamma}(hereafter L--{gamma} correlation). Furthermore, out of the 7 ULXs that have the L--{gamma} correlation, 4 ULXs also show spectral pivoting in the observed energy band. We also find that two ULXs show an L--{gamma} anti-correlation. The spectra of 4 ULXs in the sample can be adequately fitted with a MCD model. We compare these sources to known black hole binaries (BHB) and find that they follow similar paths in their luminosity-temperature (hereafter L--T) diagrams. Finally we show that the 'soft excess' reported for many of these ULXs at {approx}0.2 keV seem to follow a trend L {proportional_to} T{sup -4} when modeled with a power-law plus a 'cool' MCD model. This is contrary to the expected L {proportional_to} T{sup 4} relation that is expected from theory and what is seen for many accreting BHBs.

  11. Tabletop Ultrabright Kiloelectronvolt X-Ray Sources from Xe and Kr Hollow Atom States

    NASA Astrophysics Data System (ADS)

    Sankar, Poopalasingam

    Albert Einstein, the father of relativity, once said, "Look deep into nature, and then you will understand everything better". Today available higher resolution tabletop tool to look deep into matters and living thing is an x-ray source. Although the available tabletop x-rays sources of the 20th century, such as the ones used for medical or dental x-rays are tremendously useful for medical diagnostics and industry, a major disadvantage is that they have low quality skillful brightness, which limits its resolution and accuracy. In the other hand, x-ray free-electrons laser (XFEL) and synchrotron radiation sources provided extreme bright x-rays. However, number of applications of XFEL and synchrotron such as medical and industrials, has been hampered by their size, complexity, and cost. This has set a goal of demonstrating x-ray source with enough brightness for potential applications in an often-called tabletop compact x-ray source that could be operated in university laboratory or hospitals. We have developed two tabletop ultrabright keV x-ray sources, one from a Xe hollow-atom states and the other one from Kr hollow-atom stares with a unique characteristic that makes them complementary to currently-available extreme-light sources; XFEL, and synchrotron x-ray source. Upgraded tabletop ultra-fast KrF* pump-laser interacts with target rare-gas clusters and produces hollow-atom states, which later coherently collapse to the empty inner-shell and thereby generate keV x-ray radiation. The KrF* pump-laser beam is self-focused and forms a self-channel to guide the generated x-ray radiation in the direction of the pump-laser beam to produce directed x-ray beam. Xe (M) x-ray source operates at 1.2-1.6 nm wavelength while the Kr(L) x-ray source operates in 600-800 pm wavelength. System is mounted upon 3 optical-tables (5´x12´) with two KrF amplifiers at a repetition rate of 0.1 Hz. A lower bound for brightness value for both Xe and Kr x-ray sources is 1026 photons s-1mm-2

  12. A Chandra X-Ray Study of NGC 1068 IL the Luminous X-Ray Source Population

    NASA Technical Reports Server (NTRS)

    Smith, David A.; Wilson, Andrew S.

    2003-01-01

    We present an analysis of the compact X-ray source population in the Seyfert 2 galaxy NGC 1068, imaged with a approx. 50 ks Chandra observation. We find a total of 84 compact sources on the S3 chip, of which 66 are located within the 25.0 B-mag/arcsec isophote of the galactic disk of NGC 1068. Spectra have been obtained for the 21 sources with at least 50 counts and modeled with both multicolor disk blackbody and power-law models. The power-law model provides the better description of the spectrum for 18 of these sources. For fainter sources, the spectral index has been estimated from the hardness ratio. Five sources have 0.4 - 8 keV intrinsic luminosities greater than 10(exp 39)ergs/ s, assuming that their emission is isotropic and that they are associated with NGC 1068. We refer to these sources as intermediate-luminosity X-ray objects (ISOs). If these five sources are X-ray binaries accreting with luminosities that are both sub-Eddington and isotropic, then the implied source masses are approx greater than 7 solar mass, and so they are inferred to be black holes. Most of the spectrally modeled sources have spectral shapes similar to Galactic black hole candidates. However, the brightest compact source in NGC 1068 has a spectrum that is much harder than that found in Galactic black hole candidates and other ISOs. The brightest source also shows large amplitude variability on both short-term and long-term timescales, with the count rate possibly decreasing by a factor of 2 in approx. 2 ks during our Chundra observation, and the source flux decreasing by a factor of 5 between our observation and the grating observations taken just over 9 months later. The ratio of the number of sources with luminosities greater than 2.1 x 10(exp 38) ergs/s in the 0.4 - 8 keV band to the rate of massive (greater than 5 solar mass) star formation is the same, to within a factor of 2, for NGC 1068, the Antennae, NGC 5194 (the main galaxy in M51), and the Circinus galaxy. This suggests

  13. Directional properties of hard x-ray sources generated by tightly focused ultrafast laser pulses

    SciTech Connect

    Hou Bixue; Mordovanakis, Aghapi; Easter, James; Krushelnick, Karl; Nees, John A.

    2008-11-17

    Directional properties of ultrafast laser-based hard x-ray sources are experimentally studied using tightly focused approximately millijoule laser pulses incident on a bulk Mo target. Energy distributions of K{alpha} and total x rays, as well as source-size distributions are directionally resolved in vacuum and in flowing helium, respectively. Directional distributions of x-ray emission is more isotropic for p-polarized pump than for s-polarized. Based on source-size measurements, a simple two-location model, with expanded plasma and bulk material, is employed to represent the x-ray source profile.

  14. Sub-Picosecond Tunable Hard X-Ray Undulator Source for Laser/X-Ray Pump-Probe Experiments

    SciTech Connect

    Ingold, G.; Beaud, P.; Johnson, S.; Streun, A.; Schmidt, T.; Abela, R.; Al-Adwan, A.; Abramsohn, D.; Boege, M.; Grolimund, D.; Keller, A.; Krasniqi, F.; Rivkin, L.; Rohrer, M.; Schilcher, T.; Schmidt, T.; Schlott, V.; Schulz, L.; Veen, F. van der; Zimoch, D.

    2007-01-19

    The FEMTO source under construction at the {mu}XAS beamline is designed to enable tunable time-resolved laser/x-ray absorption and diffraction experiments in photochemistry and condensed matter with ps- and sub-ps resolution. The design takes advantage of (1) the highly stable operation of the SLS storage ring, (2) the reliable high harmonic operation of small gap, short period undulators to generate hard x-rays with energy 3-18 keV at 2.4 GeV beam energy, and (3) the progress in high power, high repetition rate fs solid-state laser technology to employ laser/e-beam 'slicing' to reach a time resolution of ultimately 100 fs. The source will profit from the inherently synchronized pump (laser I: 100 fs, 2 mJ, 1 kHz) and probe (sliced X-rays, laser II: 50 fs, 5 mJ, 1 kHz) pulses, and from the excellent stability of the SLS storage ring which is operated in top-up mode and controlled by a fast orbit feedback (FOFB). Coherent radiation emitted at THz frequencies by the sliced 100 fs electron bunches will be monitored as on-line cross-correlation signal to keep the laser-electron beam interaction at optimum. The source is designed to provide at 8 keV (100 fs) a monochromized flux of 104 ph/s/0.01% bw (Si crystal monochromator) and 106 ph/s/1.5% bw (multilayer monochromator) at the sample. It is operated in parasitic mode using a hybrid bunch filling pattern. Because of the low intensity measurements are carried out repetitively over many shots using refreshing samples and gated detectors. 'Diffraction gating' experiments will be used to characterize the sub-ps X-ray pulses.

  15. X-ray imaging detectors for synchrotron and XFEL sources

    PubMed Central

    Hatsui, Takaki; Graafsma, Heinz

    2015-01-01

    Current trends for X-ray imaging detectors based on hybrid and monolithic detector technologies are reviewed. Hybrid detectors with photon-counting pixels have proven to be very powerful tools at synchrotrons. Recent developments continue to improve their performance, especially for higher spatial resolution at higher count rates with higher frame rates. Recent developments for X-ray free-electron laser (XFEL) experiments provide high-frame-rate integrating detectors with both high sensitivity and high peak signal. Similar performance improvements are sought in monolithic detectors. The monolithic approach also offers a lower noise floor, which is required for the detection of soft X-ray photons. The link between technology development and detector performance is described briefly in the context of potential future capabilities for X-ray imaging detectors. PMID:25995846

  16. Use of electron cyclotron resonance x-ray source for nondestructive testing application

    NASA Astrophysics Data System (ADS)

    Baskaran, R.; Selvakumaran, T. S.

    2006-03-01

    Electron cyclotron resonance (ECR) technique is being used for generating x rays in the low-energy region (<150keV). Recently, the source is used for the calibration of thermoluminescent dosimetry (TLD) badges. In order to qualify the ECR x-ray source for imaging application, the source should give uniform flux over the area under study. Lead collimation arrangement is made to get uniform flux. The flux profile is measured using a teletector at different distance from the port and uniform field region of 10×10cm2 has been marked at 20cm from the x-ray exit port. A digital-to-analog converter (DAC) circuit pack is used for examining the source performance. The required dose for nondestructive testing examination has been estimated using a hospital x-ray machine and it is found to be 0.05mSv. Our source experimental parameters are tuned and the DAC circuit pack was exposed for nearly 7min to get the required dose value. The ECR x-ray source operating parameters are argon pressure: 10-5Torr, microwave power: 350W, and coil current: 0A. The effective energy of the x-ray spectrum is nearly 40keV. The x-ray images obtained from ECR x-ray source and hospital medical radiography machine are compared. It is found that the image obtained from ECR x-ray source is suitable for NDT application.

  17. Use of electron cyclotron resonance x-ray source for nondestructive testing application

    SciTech Connect

    Baskaran, R.; Selvakumaran, T.S.

    2006-03-15

    Electron cyclotron resonance (ECR) technique is being used for generating x rays in the low-energy region (<150 keV). Recently, the source is used for the calibration of thermoluminescent dosimetry (TLD) badges. In order to qualify the ECR x-ray source for imaging application, the source should give uniform flux over the area under study. Lead collimation arrangement is made to get uniform flux. The flux profile is measured using a teletector at different distance from the port and uniform field region of 10x10 cm{sup 2} has been marked at 20 cm from the x-ray exit port. A digital-to-analog converter (DAC) circuit pack is used for examining the source performance. The required dose for nondestructive testing examination has been estimated using a hospital x-ray machine and it is found to be 0.05 mSv. Our source experimental parameters are tuned and the DAC circuit pack was exposed for nearly 7 min to get the required dose value. The ECR x-ray source operating parameters are argon pressure: 10{sup -5} Torr, microwave power: 350 W, and coil current: 0 A. The effective energy of the x-ray spectrum is nearly 40 keV. The x-ray images obtained from ECR x-ray source and hospital medical radiography machine are compared. It is found that the image obtained from ECR x-ray source is suitable for NDT application.

  18. Preliminary Designs for Modifications to the X-Ray Source and Beam Monitor of the Marshall Space Flight Center's X-Ray Calibration Facility

    NASA Technical Reports Server (NTRS)

    Croft, W. L.

    1983-01-01

    Preliminary designs for modifications to the X-ray source and beam monitor of the MSFC X-Ray Calibration Facility to meet requirements for the calibration of the Advanced X-Ray Astrophysics Facility are considered. A rhodium plated copper target and rhodium foil filter are proposed as a source of X-rays of approximately 2.6 keV energy. Bragg scattering of the unpolarized X-ray beam from the present source through an angle of 90 deg by a single crystal placed on the axis of the guide tube is proposed as a source of approximately monoenergetic plane polarized X-rays. A sealed xenon proportional counter with a Beryllium window is proposed as a beam monitor for use between 2.5 and 8 keV to obtain improved detection efficiency.

  19. Observation of the X-ray source Sco X-1 from Skylab. [radiant flux density

    NASA Technical Reports Server (NTRS)

    Wilson, R. M.

    1977-01-01

    An attempt to observe the discrete X-ray source Sco X-1 on 20 September 1973 between 0856 and 0920 UT is reported. Data obtained with the ATM/S-056 X-ray event analyzer, in particular the flux observed with the 1.71 to 4.96 KeV counter, is analyzed. No photographic image of the source was obtained because Sco X-1 was outside the field of view of the X-ray telescope.

  20. Synchrotron radiation sources and condensers for projection x-ray lithography

    SciTech Connect

    Murphy, J.B.; MacDowell, A.A. ); White, D.L. ); Wood, O.R. II )

    1992-01-01

    The design requirements for a compact electron storage ring that could be used as a soft x-ray source for projection lithography are discussed. The design concepts of the x-ray optics that are required to collect and condition the radiation in divergence, uniformity and direction to properly illuminate the mask and the particular x-ray projection camera used are discussed. Preliminary designs for an entire soft x-ray projection lithography system using an electron storage ring as a soft X-ray source are presented. It is shown that by combining the existing technology of storage rings with large collection angle condensers, a powerful and reliable source of 130[Angstrom] photons for production line projection x-ray lithography is possible.

  1. Synchrotron radiation sources and condensers for projection x-ray lithography

    SciTech Connect

    Murphy, J.B.; MacDowell, A.A.; White, D.L.; Wood, O.R. II

    1992-11-01

    The design requirements for a compact electron storage ring that could be used as a soft x-ray source for projection lithography are discussed. The design concepts of the x-ray optics that are required to collect and condition the radiation in divergence, uniformity and direction to properly illuminate the mask and the particular x-ray projection camera used are discussed. Preliminary designs for an entire soft x-ray projection lithography system using an electron storage ring as a soft X-ray source are presented. It is shown that by combining the existing technology of storage rings with large collection angle condensers, a powerful and reliable source of 130{Angstrom} photons for production line projection x-ray lithography is possible.

  2. A Search for Hyperluminous X-Ray Sources in the XMM-Newton Source Catalog

    NASA Astrophysics Data System (ADS)

    Zolotukhin, I.; Webb, N. A.; Godet, O.; Bachetti, M.; Barret, D.

    2016-02-01

    We present a new method to identify luminous off-nuclear X-ray sources in the outskirts of galaxies from large public redshift surveys, distinguishing them from foreground and background interlopers. Using the 3XMM-DR5 catalog of X-ray sources and the SDSS DR12 spectroscopic sample of galaxies, with the help of this off-nuclear cross-matching technique, we selected 98 sources with inferred X-ray luminosities in the range 1041 < LX < 1044 erg s-1, compatible with hyperluminous X-ray objects (HLX). To validate the method, we verify that it allowed us to recover known HLX candidates such as ESO 243-49 HLX-1 and M82 X-1. From a statistical study, we conservatively estimate that up to 71 ± 11 of these sources may be foreground- or background sources, statistically leaving at least 16 that are likely to be HLXs, thus providing support for the existence of the HLX population. We identify two good HLX candidates and using other publicly available data sets, in particular the VLA FIRST in radio, UKIRT Infrared Deep Sky Survey in the near-infrared, GALEX in the ultraviolet and Canada-France-Hawaii Telescope Megacam archive in the optical, we present evidence that these objects are unlikely to be foreground or background X-ray objects of conventional types, e.g., active galactic nuclei, BL Lac objects, Galactic X-ray binaries, or nearby stars. However, additional dedicated X-ray and optical observations are needed to confirm their association with the assumed host galaxies and thus secure their HLX classification.

  3. The X-ray eclipse geometry of the super-soft X-ray source CAL 87

    SciTech Connect

    Ribeiro, T.; Lopes de Oliveira, R.

    2014-09-01

    We explore XMM-Newton observations of the eclipsing super-soft X-ray source CAL 87 in order to map the accretion structures of the system. Indirect imaging techniques were applied in X-ray light curves to provide eclipse maps. The surface brightness distribution exhibits an extended and symmetric emission, and a feature is revealed from the hardest X-rays that is likely due to a bright spot. A rate of P-dot =(+6±2)×10{sup −10} for changes in the orbital period of the system was derived from the eclipses. There is no significant variation of the emission lines even during eclipses, arguing that the lines are formed in an extended region. The continuum emission dominates the decrease in flux that is observed during eclipses. The O VIII Lyα line reveals a broadening velocity that is estimated to be 365{sub −69}{sup +65} km s{sup –1} (at 1σ), marginal evidence for asymmetry in its profile, and sometimes shows evidence of double-peaked emission. Together, the results support that the wind-driven mass transfer scenario is running in CAL 87.

  4. On the maximum accretion luminosity of magnetized neutron stars: connecting X-ray pulsars and ultraluminous X-ray sources

    NASA Astrophysics Data System (ADS)

    Mushtukov, Alexander A.; Suleimanov, Valery F.; Tsygankov, Sergey S.; Poutanen, Juri

    2015-12-01

    We study properties of luminous X-ray pulsars using a simplified model of the accretion column. The maximal possible luminosity is calculated as a function of the neutron star (NS) magnetic field and spin period. It is shown that the luminosity can reach values of the order of 1040 erg s-1 for the magnetar-like magnetic field (B ≳ 1014 G) and long spin periods (P ≳ 1.5 s). The relative narrowness of an area of feasible NS parameters which are able to provide higher luminosities leads to the conclusion that L ≃ 1040 erg s-1 is a good estimate for the limiting accretion luminosity of an NS. Because this luminosity coincides with the cut-off observed in the high-mass X-ray binaries luminosity function which otherwise does not show any features at lower luminosities, we can conclude that a substantial part of ultraluminous X-ray sources are accreting neutron stars in binary systems.

  5. Z pinches as intense x-ray sources for inertial confinement fusion applications

    SciTech Connect

    Matzen, M.K.

    1997-05-01

    Fast z-pinch implosions can convert more than 10% of the stored electrical energy in a pulsed-power accelerator into x-rays. On the Saturn pulsed-power accelerator at Sandia National Laboratories, currents of 6 to 8 MA with a risetime of less than 50 ns have been used to drive cylindrically-symmetric arrays of wires, producing x-ray energies greater than 400 kJ with x-ray pulsewidths less than 5 ns and peak x-ray powers of 75 {+-} 10 TW. Using similar loads, PBFA Z has produced > 1.5 MJ and > 150 TW of x-rays in the first four months of operation in the z-pinch mode. These x-ray energies and powers are records for laboratory x-ray production. The x-ray output can be thermalized into a near-Planckian x-ray source by containing it within a cylindrical radiation case (a hohlraum). These energetic, intense, large volume, long-lived hohlraum x-ray sources have recently been used for ICF-relevant ablator physics experiments and offer the potential for performing many new basic physics and fusion-relevant experiments.

  6. Infrared identification of hard X-ray sources in the Galaxy

    NASA Astrophysics Data System (ADS)

    Nebot Gómez-Morán, A.; Motch, C.; Pineau, F.-X.; Carrera, F. J.; Pakull, M. W.; Riddick, F.

    2015-09-01

    The nature of the low- to intermediate-luminosity (LX ˜ 1032-34 erg s-1) source population revealed in hard band (2-10 keV) X-ray surveys of the Galactic plane is poorly understood. To overcome such problem, we cross-correlated the XMM-Newton 3XMM-DR4 survey with the infrared Two Micron All Sky Survey and Galactic Legacy Infrared Mid-Plane Survey Extraordinaire catalogues. We identified reliable X-ray-infrared associations for 690 sources. We selected 173 sources having hard X-ray spectra, typical of hard X-ray high-mass stars (kT > 5 keV), and 517 sources having soft X-ray spectra, typical of active coronae. About 18 per cent of the soft sources are classified in the literature: ˜91 per cent as stars, with a minor fraction of Wolf-Rayet (WR) stars. Roughly 15 per cent of the hard sources are classified in the literature: ˜68 per cent as high-mass X-ray stars single or in binary systems (WR, Be and high-mass X-ray binaries - HMXBs), with a small fraction of G and B stars. We carried out infrared spectroscopic pilot observations at the William Herschel Telescope for five hard X-ray sources. Three of them are high-mass stars with spectral types WN7-8h, Ofpe/WN9 and Be, and LX ˜ 1032-1033erg s-1. One source is a colliding-wind binary, while another source is a colliding-wind binary or a supergiant fast X-ray transient in quiescence. The Be star is a likely γ-Cas system. The nature of the other two X-ray sources is uncertain. The distribution of hard X-ray sources in the parameter space made of X-ray hardness ratio, infrared colours and X-ray-to-infrared flux ratio suggests that many of the unidentified sources are new γ-Cas analogues, WRs and low LX HMXBs. However, the nature of the X-ray population with Ks ≥ 11 and average X-ray-to-infrared flux ratio remains unconstrained.

  7. The Radiation Dose Determination of the Pulsed X-ray Source

    NASA Astrophysics Data System (ADS)

    Miloichikova, I.; Stuchebrov, S.; Zhaksybayeva, G.; Wagner, A.

    2014-10-01

    In this paper the radiation dose measurement technique of the pulsed X-ray source RAP-160-5 is described. The dose rate measurement results from the pulsed X-ray beams at the different distance between the pulsed X-ray source focus and the detector obtained with the help of the thermoluminescent detectors DTL-02, the universal dosimeter UNIDOS E equipped with the plane-parallel ionization chamber type 23342, the dosimeter-radiometer DKS-96 and the radiation dosimeter AT 1123 are demonstrated. The recommendations for the dosimetry measurements of the pulsed X-ray generator RAP-160-5 under different radiation conditions are proposed.

  8. LUX - A recirculating linac-based ultrafast X-ray source

    SciTech Connect

    Corlett, J.N.; Barletta, W.A.; DeSantis, S.; Doolittle, L.; Fawley, W.M.; Green, M.A.; Heimann, P.; Leone, S.R.; Lidia, S.; Li, D.; Parmigiani, F.; Ratti, A.; Robinson, K.; Schoenlein, R.; Staples, J.; Wan, W.; Wells, R.; Wilcox, R.; Wolski, A.; Zholents, A.

    2003-08-01

    We describe the design of a proposed source of ultra-fast synchrotron radiation x-ray pulses based on a recirculating superconducting linac, with an integrated array of ultrafast laser systems. The source produces x-ray pulses with duration of 10-50 fs at a 10 kHz repetition rate, with tunability from EUV to hard x-ray regimes, and optimized for the study of ultra-fast dynamics. A high-brightness rf photocathode provides electron bunches. An injector linac accelerates the beam to the 100 MeV range, and is followed by four passes through a 700 MeV recirculating linac. Ultrafast hard x-ray pulses are obtained by a combination of electron bunch manipulation, transverse temporal correlation of the electrons, and x-ray pulse compression. EUV and soft x-ray pulses as short as 10 fs are generated in a harmonic-cascade free electron laser scheme.

  9. Long-term variability in bright hard X-ray sources: 5+ years of BATSE data

    NASA Technical Reports Server (NTRS)

    Robinson, C. R.; Harmon, B. A.; McCollough, M. L.; Paciesas, W. S.; Sahi, M.; Scott, D. M.; Wilson, C. A.; Zhang, S. N.; Deal, K. J.

    1997-01-01

    The operation of the Compton Gamma Ray Observatory (CGRO)/burst and transient source experiment (BATSE) continues to provide data for inclusion into a data base for the analysis of long term variability in bright, hard X-ray sources. The all-sky capability of BATSE provides up to 30 flux measurements/day for each source. The long baseline and the various rising and setting occultation flux measurements allow searches for periodic and quasi-periodic signals with periods of between several hours to hundreds of days to be conducted. The preliminary results from an analysis of the hard X-ray variability in 24 of the brightest BATSE sources are presented. Power density spectra are computed for each source and profiles are presented of the hard X-ray orbital modulations in some X-ray binaries, together with amplitude modulations and variations in outburst durations and intensities in recurrent X-ray transients.

  10. Flash imaging of fine structures of cellular organelles by contact x-ray microscopy with a high intensity laser plasma x-ray source

    NASA Astrophysics Data System (ADS)

    Kado, Masataka; Ishino, Masahiko; Kishimoto, Maki; Tamotsu, Satoshi; Yasuda, Keiko; Kinjo, Yasuhito; Shinohara, Kunio

    2011-09-01

    X-ray flash imaging by contact microscopy with a highly intense laser-plasma x-ray source was achieved for the observation of wet biological cells. The exposure time to obtain a single x-ray image was about 600 ps as determined by the pulse duration of the driving laser pulse. The x-ray flash imaging makes it possible to capture an x-ray image of living biological cells without any artificial treatment such as staining, fixation, freezing, and so on. The biological cells were cultivated directly on the surface of the silicon nitride membranes, which are used for the x-ray microscope. Before exposing the cells to x-rays they were observed by a conventional fluorescent microscope as reference, since the fluorescent microscopes can visualize specific organelles stained with fluorescent dye. Comparing the x-ray images with the fluorescent images of the exact same cells, each cellular organelle observed in the x-ray images was identified one by one and actin filaments and mitochondria were clearly identified in the x-ray images.

  11. Transmission type flat-panel X-ray source using ZnO nanowire field emitters

    SciTech Connect

    Chen, Daokun; Song, Xiaomeng; Zhang, Zhipeng; Chen, Jun; Li, Ziping; She, Juncong; Deng, Shaozhi; Xu, Ningsheng

    2015-12-14

    A transmission type flat-panel X-ray source in diode structure was fabricated. Large-scale patterned ZnO nanowires grown on a glass substrate by thermal oxidation were utilized as field emitters, and tungsten thin film coated on silica glass was used as the transmission anode. Uniform distribution of X-ray generation was achieved, which benefited from the uniform electron emission from ZnO nanowires. Self-ballasting effect induced by the intrinsic resistance of ZnO nanowire and decreasing of screening effect caused by patterned emitters account for the uniform emission. Characteristic X-ray peaks of W-L lines and bremsstrahlung X-rays have been observed under anode voltages at a range of 18–20 kV, the latter of which were the dominant X-ray signals. High-resolution X-ray images with spatial resolution less than 25 μm were obtained by the flat-panel X-ray source. The high resolution was attributed to the small divergence angle of the emitted X-rays from the transmission X-ray source.

  12. Transmission type flat-panel X-ray source using ZnO nanowire field emitters

    NASA Astrophysics Data System (ADS)

    Chen, Daokun; Song, Xiaomeng; Zhang, Zhipeng; Li, Ziping; She, Juncong; Deng, Shaozhi; Xu, Ningsheng; Chen, Jun

    2015-12-01

    A transmission type flat-panel X-ray source in diode structure was fabricated. Large-scale patterned ZnO nanowires grown on a glass substrate by thermal oxidation were utilized as field emitters, and tungsten thin film coated on silica glass was used as the transmission anode. Uniform distribution of X-ray generation was achieved, which benefited from the uniform electron emission from ZnO nanowires. Self-ballasting effect induced by the intrinsic resistance of ZnO nanowire and decreasing of screening effect caused by patterned emitters account for the uniform emission. Characteristic X-ray peaks of W-L lines and bremsstrahlung X-rays have been observed under anode voltages at a range of 18-20 kV, the latter of which were the dominant X-ray signals. High-resolution X-ray images with spatial resolution less than 25 μm were obtained by the flat-panel X-ray source. The high resolution was attributed to the small divergence angle of the emitted X-rays from the transmission X-ray source.

  13. X-ray source brightness comparison: Rigaku rotating anode source vs. Kevex microfocus tube

    SciTech Connect

    Koch, J A; Dewald, E; Kozioziemski, B

    2010-03-17

    In 2007, we began to explore alternative x-ray sources for application to refraction-enhanced (phase contrast) x-ray radiography of cryogenic NIF ignition capsules containing frozen deuterium-tritium (D-T) ice layers. These radiographs are currently obtained using Kevex microfocus tubes as backlights, and for these sources the x-ray source size is approximately 5 {micro}m. As part of this exploration, we obtained refraction-enhanced radiographs of empty plastic capsules using the Janus laser facility at LLNL, demonstrating that even large ({approx} 100 {micro}m) sources can be utilized in refraction-enhanced radiography provided the source/sample distance is sufficiently large, and provided the final x-ray detector has sufficient spatial resolution. Essentially, in the current geometry, we rely on a small source to provide spatial resolution and on the source/sample distance to provide refraction contrast, but an equally useful alternative geometry is to use a large source and rely on fine detector spatial resolution to provide spatial resolution and on the sample/detector distance to provide refraction contrast.

  14. DEVELOPMENT OF NEW MID-INFRARED ULTRAFAST LASER SOURCES FOR COMPACT COHERENT X-RAY SOURCES

    SciTech Connect

    Sterling Backus

    2012-05-14

    In this project, we proposed to develop laser based mid-infrared lasers as a potentially robust and reliable source of ultrafast pulses in the mid-infrared region of the spectrum, and to apply this light source to generating bright, coherent, femtosecond-to-attosecond x-ray beams.

  15. Course Manual for Machine Sources of X Rays.

    ERIC Educational Resources Information Center

    Food and Drug Administration (DHEW), Rockville, MD. Bureau of Radiological Health.

    This is the first of a series of three instructor manuals in x-ray science and engineering and is produced as part of a project of Oregon State University's Bureau of Radiological Health. This manual, and the two companion manuals, have been tested in courses at Oregon State. These materials have been designed to serve as models for teaching and…

  16. X-ray interferometry development at the Advanced Photon Source.

    SciTech Connect

    Fezzaa, K.; Lee, W.-K.

    1999-11-22

    In this paper, we report initial test results of a four-bounce Bragg reflection X-ray interferometer at 7.46 keV and, for the first time to our knowledge, at the higher energy of 14.91 keV where the spectral acceptance is much smaller.

  17. Spectral unfolds of PITHON Flash X-ray source.

    SciTech Connect

    Zarick, Thomas Andrew; Sheridan, Timothy J.; Hartman, E. Frederick; Riordan, John C.

    2007-11-01

    Using a differential absorption spectrometer we obtained experimental spectral information for the PITHON Flash X-ray Machine located in San Leandro, California at L-3 Communications. Spectral information we obtained pertained to the 200 keV to 800 keV endpoint operation of PITHON. We also obtained data on the temporal behavior of high energy and low energy spectral content.

  18. X-Ray Point Sources in the Sombrero Galaxy: Very Soft Sources, the Globular Cluster/Low-Mass X-Ray Binary Connection, and an Overview

    NASA Astrophysics Data System (ADS)

    Di Stefano, R.; Kong, A. K. H.; VanDalfsen, M. L.; Harris, W. E.; Murray, S. S.; Delain, K. M.

    2003-12-01

    We report on the population of point sources discovered during an 18.5 ks Chandra ACIS-S observation of the Sombrero galaxy. We present the luminosity function and the spectra of the six brightest sources, consider correlations with globular clusters (GCs) and with planetary nebulae, and study the galaxy's population of very soft sources. We detected 122 sources. Twenty-two sources are identified as very soft; of these, five appear to be classical luminous supersoft X-ray sources (SSSs), while 17 may belong to the slightly harder class referred to as quasi-soft (QSSs). There is an overdensity of very soft sources within 2 kpc of the nucleus, which is itself the brightest X-ray source. Very soft sources are also found in the disk and halo, with one QSS in a globular cluster (GC). This source is somewhat harder than most SSSs; the energy distribution of its photons is consistent with what is expected from an accreting intermediate-mass black hole. Several sources in the Sombrero's halo are good candidates for SSS models in which the accretor is a nuclear-burning white dwarf. In total, 32 X-ray sources are associated with GCs. The majority of sources with luminosity greater than 1038 ergs s-1 are in GCs. These results for M104, an Sa galaxy, are similar to what has been found for elliptical galaxies and for the late-type spiral M31. We find that those optically bright GCs with X-ray sources house only the brightest X-ray sources. We find that, in common with other galaxies, there appears to be a positive connection between young (metal-rich) GCs and X-ray sources but that the brightest X-ray sources are equally likely to be in metal-poor GCs. The luminosity function of X-ray sources in GCs has a cut-off near the Eddington luminosity for a 1.4 Msolar object. We propose a model that can explain the trends seen in the data sets from the Sombrero and other galaxies. Thermal timescale mass transfer can occur in some of the younger clusters in which the turnoff mass is

  19. Source effects in analyzer-based X-ray phase contrast imaging with conventional sources

    SciTech Connect

    Hoennicke, M. G.; Manica, J.; Mazzaro, I.; Cusatis, C.; Huang, X.-R.

    2012-11-15

    Several recent papers have shown the implementation of analyzer based X-ray phase contrast imaging (ABI) with conventional X-ray sources. The high flux is always a requirement to make the technique useful for bio-medical applications. Here, we present and discuss three important parameters, which need to be taken into account, when searching for the high flux ABI: anisotropic magnification, double image, and source size spread due to intrinsic dispersive diffraction by asymmetrically cut crystals. These parameters, if not well optimized, may cause important features in the acquired images which can mislead the interpretation. A few ways to minimize these effects are implemented and discussed, including some experimental results.

  20. THREE NEW GALACTIC CENTER X-RAY SOURCES IDENTIFIED WITH NEAR-INFRARED SPECTROSCOPY

    SciTech Connect

    DeWitt, Curtis; Bandyopadhyay, Reba M.; Eikenberry, Stephen S.; Sarajedini, Ata; Sellgren, Kris; Blum, Robert; Olsen, Knut; Bauer, Franz E.

    2013-11-01

    We have conducted a near-infrared spectroscopic survey of 47 candidate counterparts to X-ray sources discovered by the Chandra X-Ray Observatory near the Galactic center (GC). Though a significant number of these astrometric matches are likely to be spurious, we sought out spectral characteristics of active stars and interacting binaries, such as hot, massive spectral types or emission lines, in order to corroborate the X-ray activity and certify the authenticity of the match. We present three new spectroscopic identifications, including a Be high-mass X-ray binary (HMXB) or a γ Cassiopeiae (Cas) system, a symbiotic X-ray binary, and an O-type star of unknown luminosity class. The Be HMXB/γ Cas system and the symbiotic X-ray binary are the first of their classes to be spectroscopically identified in the GC region.

  1. Spectroscopic Measurement of L X-Rays Emitted by 241Am Source by TES Microcalorimeter

    NASA Astrophysics Data System (ADS)

    Maeda, M.; Yamaguchi, K.; Maehata, K.; Iyomoto, N.; Ishibashi, K.; Takasaki, K.; Nakamura, K.; Tanaka, K.; Yamanaka, Y.

    2012-06-01

    Nondestructive plutonium monitoring during reprocessing of spent nuclear fuel and in mixed-oxide-fuel fabrication facilities is expected to require spectroscopic measurements of L X-rays ranging from 10 to 20 keV. To this end, L X-ray emission intensities of transuranium elements will be important parameters in estimating the plutonium isotopic composition from L X-ray spectra. However, owing to fine structure within the L X-ray spectra, significant discrepancies exist among theoretical values, reference and experimental data concerning these emission intensities. To obtain better spectroscopic measurements, we used a TES microcalorimeter to get the energy spectrum of L X-rays emitted by 237Np resulting from α-decay of a 241Am source. Values for the L X-ray emission intensities were estimated by analyzing the spectral data and compared with previous data. We advocate for improvements in evaluation of emission intensities given the enhanced precision afforded by TES microcalorimetry.

  2. GSFC Contributions to the NATO X-ray Astronomy Institute, Erice, July 1979. [X-ray spectra of supernova remants, galactic X-ray sources, active galactic nuclei, and clusters of galaxies

    NASA Technical Reports Server (NTRS)

    Holt, S. S.; Mushotzky, R. F.

    1979-01-01

    An overview of X-ray astronomical spectroscopy in general is presented and results obtained by HEAO 1 and 2 as well as earlier spacecraft are examined. Particular emphasis is given to the spectra of supernova remnants; galactic binary X-ray sources, cataclysmic variables, bulges, pulsars, and stars; the active nuclei of Seyfert 1 galaxy, BL Lac, and quasars; the diffuse X-ray background; and galactic clusters.

  3. Picosecond soft-x-ray pulses from a high-intensity laser-plasma source.

    PubMed

    Pelletier, J F; Chaker, M; Kieffer, J C

    1996-07-15

    We report time-resolved spectroscopic analysis of laser-produced plasma x-ray sources. Plasmas produced by a 400-fs 1-TW tabletop laser are characterized with a transmission grating spectrometer coupled to a soft-x-ray streak camera. Soft-x-ray radiation in the 1-6-nm range with durations of 2-7 ps is observed for copper and tantalum plasmas. The effect of incident laser energy on the x-ray pulse duration is also investigated. PMID:19876245

  4. CHANDRA ACIS Survey of X-Ray Point Sources: The Source Catalog

    NASA Astrophysics Data System (ADS)

    Wang, Song; Liu, Jifeng; Qiu, Yanli; Bai, Yu; Yang, Huiqin; Guo, Jincheng; Zhang, Peng

    2016-06-01

    The Chandra archival data is a valuable resource for various studies on different X-ray astronomy topics. In this paper, we utilize this wealth of information and present a uniformly processed data set, which can be used to address a wide range of scientific questions. The data analysis procedures are applied to 10,029 Advanced CCD Imaging Spectrometer observations, which produces 363,530 source detections belonging to 217,828 distinct X-ray sources. This number is twice the size of the Chandra Source Catalog (Version 1.1). The catalogs in this paper provide abundant estimates of the detected X-ray source properties, including source positions, counts, colors, fluxes, luminosities, variability statistics, etc. Cross-correlation of these objects with galaxies shows that 17,828 sources are located within the D 25 isophotes of 1110 galaxies, and 7504 sources are located between the D 25 and 2D 25 isophotes of 910 galaxies. Contamination analysis with the log N–log S relation indicates that 51.3% of objects within 2D 25 isophotes are truly relevant to galaxies, and the “net” source fraction increases to 58.9%, 67.3%, and 69.1% for sources with luminosities above 1037, 1038, and 1039 erg s‑1, respectively. Among the possible scientific uses of this catalog, we discuss the possibility of studying intra-observation variability, inter-observation variability, and supersoft sources (SSSs). About 17,092 detected sources above 10 counts are classified as variable in individual observation with the Kolmogorov–Smirnov (K–S) criterion (P K–S < 0.01). There are 99,647 sources observed more than once and 11,843 sources observed 10 times or more, offering us a wealth of data with which to explore the long-term variability. There are 1638 individual objects (∼2350 detections) classified as SSSs. As a quite interesting subclass, detailed studies on X-ray spectra and optical spectroscopic follow-up are needed to categorize these SSSs and pinpoint their properties. In

  5. Guidelines for using a 10-keV x-ray source for hardness assurance

    SciTech Connect

    Fleetwood, D.M.

    1986-01-01

    In this paper, work done at Sandia is summarized that demonstrates that it is possible to use a 10-keV x-ray source for hardness assurance. Transistor data is presented that shows that a 10-keV x-ray source can be used as a reliable process monitor, in the sense that Co-60 part response can be predicted easily and reliably from x-ray part response. Further, test structure and functional part data is presented that illustrates how an x-ray source may be employed for wafer lot acceptance for silicon-gate CMOS devices that either employ quardbands or hardened field oxides for device isolation. Finally, a few words are said about the use of high-Z gate metallizations. These results should provide guidelines for implementation of lot acceptance testing with a 10-keV x-ray source.

  6. A simulation of X-ray shielding for a superconducting electron cyclotron resonance ion source

    SciTech Connect

    Park, Jin Yong; Won, Mi-Sook; Lee, Byoung-Seob; Yoon, Jang-Hee; Choi, Seyong; Ok, Jung-Woo; Choi, Jeong-Sik; Kim, Byoung-Chul

    2014-02-15

    It is generally assumed that large amounts of x-rays are emitted from the ion source of an Electron Cyclotron Resonance (ECR) instrument. The total amount of x-rays should be strictly limited to avoid the extra heat load to the cryostat of the superconducting ECR ion source, since they are partly absorbed by the cold mass into the cryostat. A simulation of x-ray shielding was carried out to determine the effective thickness of the x-ray shield needed via the use of Geant4. X-ray spectra of the 10 GHz Nanogan ECR ion source were measured as a function of the thickness variation in the x-ray shield. The experimental results were compared with Geant4 results to verify the effectiveness of the x-ray shield. Based on the validity in the case of the 10 GHz ECR ion source, the x-ray shielding results are presented by assuming the spectral temperature of the 28 GHz ECR ion source.

  7. Studies of Supersoft X-ray Sources (SSS) and Quasisoft X-ray Sources (QSS) in the Milky Way and Magellanic Clouds

    NASA Astrophysics Data System (ADS)

    Pun, Chun-Shing J.; Li, K.; Kong, A. K. H.; DiStefano, R.

    2010-03-01

    Quasisoft X-ray sources (QSSs) are luminous (L > 1036 erg s-1, kT between 120eV and 350eV) X-ray sources emitting few or no photons at energy above 2 keV yet clearly emitting at above 1.1 keV. While their spectra are harder than luminous supersoft X-ray sources (SSSs), which have characteristic temperatures of tens of eV, QSSs are significantly softer than most canonical X-ray sources. They have been identified in elliptical galaxies, spiral galaxies (in both spiral arms and halos), and globular clusters. We report here on the progress of a comprehensive and systematic search of SSSs and QSSs in the Milky Way and in the Magellanic Clouds using archival X-ray data. Our focus is to conduct an optimized search to identify all candidates in order to differentiate between the different natures of SSSs and QSSs. The candidates collected would be checked for counterparts in other wavelengths, which could possibly help us to determine the fundamental nature of these sources, including the properties, if present, of the accretors and the accretion disks. This work is supported by a Hong Kong SAR Research Grants Council General Research Fund and by a NASA ADP grant.

  8. The scaling of X-ray variability with luminosity in ultra-luminous X-ray sources

    NASA Astrophysics Data System (ADS)

    González-Martín, O.; Papadakis, I.; Reig, P.; Zezas, A.

    2011-02-01

    Aims: We investigate the relationship between the X-ray variability amplitude and X-ray luminosity for a sample of 14 bright ultra-luminous X-ray sources (ULXs) with XMM-Newton/EPIC data, and compare it with the well-established, similar relationship for active galactic nuclei (AGN). Methods: We computed the normalised excess variance in the 2-10 keV light curves of these objects and their 2-10 keV band intrinsic luminosity L2-10 keV. We also determined model "variability-luminosity" relationships for AGN, under several assumptions regarding their power-spectral shape. We compared these model predictions at low luminosities with the ULX data. Results: The variability amplitude of the ULXs is significantly smaller than expected from a simple extrapolation of the AGN "variability-luminosity" relationship at low luminosities. We also find evidence of an anti-correlation between the variability amplitude and L2-10 keV for ULXs. The shape of this relationship is consistent with the AGN data but only if the ULXs data are shifted by four orders of magnitudes in luminosity. Conclusions: Most (but not all) of the ULXs could be "scaled-down" version of AGN if we assume that i) their black hole mass and accretion rate are between ~(2.5-30)× 103 M⊙ and ~1-80% of the Eddington limit and ii) their power spectral density has a doubly broken power-law shape. This shape and accretion rate is consistent with Galactic black hole systems operating in their so-called "low-hard" and "very-high" states.

  9. Using a 10-keV x-ray source for hardness assurance

    SciTech Connect

    Fleetwood, D.M.; Beegle, R.W.; Sexton, F.W.; Winokur, P.S.; Miller, S.L.; Schwank, J.R.; Jones, R.V.; McWhorter, P.J.

    1986-01-01

    It is shown that a 10 keV x-ray source can be used to predict the responses of microelectronic circuits to Co-60 irradiation. Guidelines for using an x-ray tester in a hardness assurance program for VLSI CMOS circuits are suggested. 5 refs., 2 figs., 1 tbl.

  10. Shielded radiography with a laser-driven MeV-energy X-ray source

    NASA Astrophysics Data System (ADS)

    Chen, Shouyuan; Golovin, Grigory; Miller, Cameron; Haden, Daniel; Banerjee, Sudeep; Zhang, Ping; Liu, Cheng; Zhang, Jun; Zhao, Baozhen; Clarke, Shaun; Pozzi, Sara; Umstadter, Donald

    2016-01-01

    We report the results of experimental and numerical-simulation studies of shielded radiography using narrowband MeV-energy X-rays from a compact all-laser-driven inverse-Compton-scattering X-ray light source. This recently developed X-ray light source is based on a laser-wakefield accelerator with ultra-high-field gradient (GeV/cm). We demonstrate experimentally high-quality radiographic imaging (image contrast of 0.4 and signal-to-noise ratio of 2:1) of a target composed of 8-mm thick depleted uranium shielded by 80-mm thick steel, using a 6-MeV X-ray beam with a spread of 45% (FWHM) and 107 photons in a single shot. The corresponding dose of the X-ray pulse measured in front of the target is ∼100 nGy/pulse. Simulations performed using the Monte-Carlo code MCNPX accurately reproduce the experimental results. These simulations also demonstrate that the narrow bandwidth of the Compton X-ray source operating at 6 and 9 MeV leads to a reduction of deposited dose as compared to broadband bremsstrahlung sources with the same end-point energy. The X-ray beam's inherently low-divergence angle (∼mrad) is advantageous and effective for interrogation at standoff distance. These results demonstrate significant benefits of all-laser driven Compton X-rays for shielded radiography.