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Sample records for compact x-ray source

  1. 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.

  2. 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.

  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. 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

  5. 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.

  6. Motionless phase stepping in X-ray phase contrast imaging with a compact source

    PubMed Central

    Miao, Houxun; Chen, Lei; Bennett, Eric E.; Adamo, Nick M.; Gomella, Andrew A.; DeLuca, Alexa M.; Patel, Ajay; Morgan, Nicole Y.; Wen, Han

    2013-01-01

    X-ray phase contrast imaging offers a way to visualize the internal structures of an object without the need to deposit significant radiation, and thereby alleviate the main concern in X-ray diagnostic imaging procedures today. Grating-based differential phase contrast imaging techniques are compatible with compact X-ray sources, which is a key requirement for the majority of clinical X-ray modalities. However, these methods are substantially limited by the need for mechanical phase stepping. We describe an electromagnetic phase-stepping method that eliminates mechanical motion, thus removing the constraints in speed, accuracy, and flexibility. The method is broadly applicable to both projection and tomography imaging modes. The transition from mechanical to electromagnetic scanning should greatly facilitate the translation of X-ray phase contrast techniques into mainstream applications. PMID:24218599

  7. Compact source of narrowband and tunable X-rays for radiography

    NASA Astrophysics Data System (ADS)

    Banerjee, Sudeep; Chen, Shouyuan; Powers, Nathan; Haden, Daniel; Liu, Cheng; Golovin, G.; Zhang, Jun; Zhao, Baozhen; Clarke, S.; Pozzi, S.; Silano, J.; Karwowski, H.; Umstadter, Donald

    2015-05-01

    We discuss the development of a compact X-ray source based on inverse-Compton scattering with a laser-driven electron beam. This source produces a beam of high-energy X-rays in a narrow cone angle (5-10 mrad), at a rate of 108 photons-s-1. Tunable operation of the source over a large energy range, with energy spread of ∼50%, has also been demonstrated. Photon energies >10 MeV have been obtained. The narrowband nature of the source is advantageous for radiography with low dose, low noise, and minimal shielding.

  8. A compact soft X-ray microscope using an electrode-less Z-pinch source

    NASA Astrophysics Data System (ADS)

    Horne, S. F.; Silterra, J.; Holber, W.

    2009-09-01

    Soft X-rays (< 1Kev) are of medical interest both for imaging and microdosimetry applications. X-ray sources at this low energy present a technological challenge. Synchrotrons, while very powerful and flexible, are enormously expensive national research facilities. Conventional X-ray sources based on electron bombardment can be compact and inexpensive, but low x-ray production efficiencies at low electron energies restrict this approach to very low power applications. Laser-based sources tend to be expensive and unreliable. Energetiq Technology, Inc. (Woburn, MA, USA) markets a 92 eV, 10W(2pi sr) electrode-less Z-pinch source developed for advanced semiconductor lithography. A modified version of this commercial product has produced 400 mW at 430 eV (2pi sr), appropriate for water window soft X-ray microscopy. The US NIH has funded Energetiq to design and construct a demonstration microscope using this source, coupled to a condenser optic, as the illumination system. The design of the condenser optic matches the unique characteristics of the source to the illumination requirements of the microscope, which is otherwise a conventional design. A separate program is underway to develop a microbeam system, in conjunction with the RARAF facility at Columbia University, NY, USA. The objective is to develop a focused, sub-micron beam capable of delivering > 1 Gy/second to the nucleus of a living cell. While most facilities of this type are coupled to a large and expensive particle accelerator, the Z-pinch X-ray source enables a compact, stand-alone design suitable to a small laboratory. The major technical issues in this system involve development of suitable focusing X-ray optics. Current status of these programs will be reported. (Supported by NIH grants 5R44RR022488-03 and 5R44RR023753-03)

  9. X-Ray Analysis of Point Sources and Diffuse Gas in Hickson Compact Groups

    NASA Astrophysics Data System (ADS)

    Broming, Emma J.; Fuse, C.

    2010-01-01

    In an effort to determine the evolutionary state of Hickson Compact Groups (HCGs), we have performed an analysis of the sixteen HCGs in the Chandra X-Ray Observatory archives. HCGs are dense galactic systems, interacting on short time scales, which are ideal for studying galaxy mergers and interactions. We have analyzed both the diffuse gas emission of the compact groups as well as their associated individual point source populations. The total X-ray gas and total point source luminosities were used to determine the group's state of evolution. It was expected that the point source activity would allow for a clear-cut separation between compact groups in different evolutionary states. The sample groups were sorted into three evolutionary categories. Type-A groups are young systems, displaying a group dominated by spiral galaxies, active star formation, and little intragroup X-ray gas. Type-B groups are characterized by an intermediate X-ray point source population, an increased activity and interaction between group members, and intermediate diffuse gas component. HCG 97 is an example of a type-B system. It contains an intragroup gas medium, and eleven associated point sources. As the system further evolves, we expect to find a greater number of point sources. Type-C systems display an advanced stage of interaction between members, an extensive luminous point source population and a large diffuse gas reservoir. HCG 92, Stephan's Quintet, is the archetypical type-C system; it contains a large intragroup gas halo and twenty-six associated point sources. The archival HCGs investigated display a positive correlation between total point source luminosity and total diffuse gas luminosity. The results suggest X-ray point sources can be used to evaluate the evolutionary state of a group. Further research will probe the connection between fully coalesced compact groups and isolated elliptical galaxies.

  10. Time-dependent spherically symmetric accretion onto compact X-ray sources

    NASA Technical Reports Server (NTRS)

    Cowie, L. L.; Ostriker, J. P.; Stark, A. A.

    1978-01-01

    Analytical arguments and a numerical hydrodynamic code are used to investigate spherically symmetric accretion onto a compact object, in an attempt to provide some insight into gas flows heated by an outgoing X-ray flux. It is shown that preheating of spherically symmetric accretion flows by energetic radiation from an X-ray source results in time-dependent behavior for a much wider range of source parameters than was determined previously and that there are two distinct types of instability. The results are compared with observations of X-ray bursters and transients as well as with theories on quasars and active galactic nuclei that involve quasi-spherically symmetric accretion onto massive black holes. Models based on spherically symmetric accretion are found to be inconsistent with observations of bursters and transients.

  11. High intensity compact Compton X-ray sources: Challenges and potential of applications

    NASA Astrophysics Data System (ADS)

    Jacquet, M.

    2014-07-01

    Thanks to the exceptional development of high power femtosecond lasers in the last 15 years, Compton based X-ray sources are in full development over the world in the recent years. Compact Compton sources are able to combine the compactness of the instrument with a beam of high intensity, high quality, tunable in energy. In various fields of applications such as biomedical science, cultural heritage preservation and material science researches, these sources should provide an easy working environment and the methods currently used at synchrotrons could be largely developed in a lab-size environment as hospitals, labs, or museums.

  12. 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.

  13. Compact galactic X-ray sources; Proceedings of the Workshop, Washington, D.C., April 20, 21, 1979

    NASA Technical Reports Server (NTRS)

    Lamb, F. (Editor); Pines, D.

    1979-01-01

    The current status and future prospects regarding the study of compact galactic X-ray sources are reviewed; key questions addressable by X-ray observations are outlined, and various proposed types of missions are evaluated in terms of their ability to address these questions. Subjects discussed include degenerate dwarfs and cataclysmic variables, bursters, neutron stars, black holes, and erratic variables, transients, and patrol programs. Specific topics include future X-ray observations of magnetic binaries, the thermonuclear-flash model for X-ray burst sources, neutron star X-ray sources, prospects for experimental research on black holes in binary systems, and compact X-ray source observations after Explorer with the LAMAR.

  14. Monochromatic computed tomography with a compact laser-driven X-ray source.

    PubMed

    Achterhold, K; Bech, M; Schleede, S; Potdevin, G; Ruth, R; Loewen, R; Pfeiffer, F

    2013-01-01

    A laser-driven electron-storage ring can produce nearly monochromatic, tunable X-rays in the keV energy regime by inverse Compton scattering. The small footprint, relative low cost and excellent beam quality provide the prospect for valuable preclinical use in radiography and tomography. The monochromaticity of the beam prevents beam hardening effects that are a serious problem in quantitative determination of absorption coefficients. These values are important e.g. for osteoporosis risk assessment. Here, we report quantitative computed tomography (CT) measurements using a laser-driven compact electron-storage ring X-ray source. The experimental results obtained for quantitative CT measurements on mass absorption coefficients in a phantom sample are compared to results from a rotating anode X-ray tube generator at various peak voltages. The findings confirm that a laser-driven electron-storage ring X-ray source can indeed yield much higher CT image quality, particularly if quantitative aspects of computed tomographic imaging are considered.

  15. Large scale X-ray and radio structures associated with compact extragalactic sources

    NASA Technical Reports Server (NTRS)

    Biermann, P.; Pauliny-Toth, I. I. K.; Witzel, A.; Fricke, K.; Johnston, K. J.; Kuehr, H.; Strittmatter, P. A.; Urbanik, M.

    1982-01-01

    Knots of X-ray emission have been detected within 20 arcmin of five compact sources initially selected from the MPIfR north polar 5 GHz survey. Two of the knots have also been detected at centimeter wavelengths and probably have nonthermal spectra. They appear to be associated with the compact sources since the probability of serendipitous discovery at the observed flux levels is low. While the apparent association may be due to colocation of the sources in a distant supercluster, it is suggested on the basis of overall alignment, and possible correlations with structures in the respective central sources, that the association may be similar to that found in extended radio sources. The observed emission may thus be due to synchrotron or inverse Compton radiation, the energy being supplied by jets from the central source.

  16. A compact Compton backscatter X-ray source for mammography and coronary angiography

    SciTech Connect

    Nguyen, D.C.; Kinross-Wright, J.M.; Weber, M.E.; Volz, S.K.; Gierman, S.M.; Hayes, K.; Vernon, W.; Goldstein, D.J.

    1998-11-01

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The project objective is to generate a large flux of tunable, monochromatic x-rays for use in mammography and coronary angiography. The approach is based on Compton backscattering of an ultraviolet solid-state laser beam against the high-brightness 20-MeV electron beams from a compact linear accelerator. The direct Compton backscatter approach failed to produce a large flux of x-rays due to the low photon flux of the scattering solid-state laser. The authors have modified the design of a compact x-ray source to the new Compton backscattering geometry with use of a regenerative amplifier free-electron laser. They have successfully demonstrated the production of a large flux of infrared photons and a high-brightness electron beam focused in both dimensions for performing Compton backscattering in a regenerative amplifier geometry.

  17. DNA strand breaks induced by soft X-ray pulses from a compact laser plasma source

    NASA Astrophysics Data System (ADS)

    Adjei, Daniel; Wiechec, Anna; Wachulak, Przemyslaw; Ayele, Mesfin Getachew; Lekki, Janusz; Kwiatek, Wojciech M.; Bartnik, Andrzej; Davídková, Marie; Vyšín, Luděk; Juha, Libor; Pina, Ladislav; Fiedorowicz, Henryk

    2016-03-01

    Application of a compact laser plasma source of soft X-rays in radiobiology studies is demonstrated. The source is based on a laser produced plasma as a result of irradiation of a double-stream gas puff target with nanosecond laser pulses from a commercially available Nd:YAG laser. The source allows irradiation of samples with soft X-ray pulses in the "water window" spectral range (wavelength: 2.3-4.4 nm; photon energy: 280-560 eV) in vacuum or a helium atmosphere at very high-dose rates and doses exceeding the kGy level. Single-strand breaks (SSB) and double-strand breaks (DBS) induced in DNA plasmids pBR322 and pUC19 have been measured. The different conformations of the plasmid DNA were separated by agarose gel electrophoresis. An exponential decrease in the supercoiled form with an increase in linear and relaxed forms of the plasmids has been observed as a function of increasing photon fluence. Significant difference between SSB and DSB in case of wet and dry samples was observed that is connected with the production of free radicals in the wet sample by soft X-ray photons and subsequent affecting the plasmid DNA. Therefore, the new source was validated to be useful for radiobiology experiments.

  18. 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.

  19. Investigating radial wire array Z pinches as a compact x-ray source on the Saturn generator

    DOE PAGES

    Ampleford, David J.; Bland, S. N.; Jennings, Christopher A.; Lebedev, S. V.; Chittenden, J. P.; Cuneo, Michael E.; McBride, Ryan D.; Jones, Brent Manley; Hall, G. N.; Suzuki-Vidal, F.; et al

    2015-08-27

    Radial wire array z pinches, where wires are positioned radially outward from a central cathode to a concentric anode, can act as a compact bright x-ray source that could potentially be used to drive a hohlraum. Experiments were performed on the 7-MA Saturn generator using radial wire arrays. These experiments studied a number of potential risks in scaling radial wire arrays up from the 1-MA level, where they have been shown to be a promising compact X-ray source. Data indicates that at 7 MA, radial wire arrays can radiate ~9 TW with 10-ns full-width at half-maximum from a compact pinch.

  20. 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.

  1. Downscattering due to Wind Outflows in Compact X-ray Sources: Theory and Interpretation

    NASA Technical Reports Server (NTRS)

    Titarchuk, Lev; Shrader, Chris

    2004-01-01

    A number of recent lines of evidence point towards the presence of hot, outflowing plasma from the central regions of compact Galactic and extragalactic X-ray sources. Additionally, it has long been noted that many of these sources exhibit an "excess" continuum component, above approx. 10 keV, usually attributed to Compton Reflection from a static medium. Motivated by these facts, as well as by recent observational constraints on the Compton reflection models - specifically apparently discrepant variability timescales for line and continuum components in some cases - we consider possible of effects of out-flowing plasma on the high-energy continuum spectra of accretion powered compact objects. We present a general formulation for photon downscattering diffusion which includes recoil and Comptonization effects due to divergence of the flow. We then develop an analytical theory for the spectral formation in such systems that allows us to derive formulae for the emergent spectrum. Finally we perform the analytical model fitting on several Galactic X-ray binaries. Objects which have been modeled with high-covering-fraction Compton reflectors, such as GS1353-64 are included in our analysis. In addition, Cyg X-3, is which is widely believed to be characterized by dense circumstellar winds with temperature of order 10(exp 6) K, provides an interesting test case. Data from INTEGRAL and RXTE covering the approx. 3 - 300 keV range are used in our analysis. We further consider the possibility that the widely noted distortion of the power-law continuum above 10 keV may in some cases be explained by these spectral softening effects.

  2. Quantitative X-ray phase-contrast microtomography from a compact laser-driven betatron source

    PubMed Central

    Wenz, J.; Schleede, S.; Khrennikov, K.; Bech, M.; Thibault, P.; Heigoldt, M.; Pfeiffer, F.; Karsch, S.

    2015-01-01

    X-ray phase-contrast imaging has recently led to a revolution in resolving power and tissue contrast in biomedical imaging, microscopy and materials science. The necessary high spatial coherence is currently provided by either large-scale synchrotron facilities with limited beamtime access or by microfocus X-ray tubes with rather limited flux. X-rays radiated by relativistic electrons driven by well-controlled high-power lasers offer a promising route to a proliferation of this powerful imaging technology. A laser-driven plasma wave accelerates and wiggles electrons, giving rise to a brilliant keV X-ray emission. This so-called betatron radiation is emitted in a collimated beam with excellent spatial coherence and remarkable spectral stability. Here we present a phase-contrast microtomogram of a biological sample using betatron X-rays. Comprehensive source characterization enables the reconstruction of absolute electron densities. Our results suggest that laser-based X-ray technology offers the potential for filling the large performance gap between synchrotron- and current X-ray tube-based sources. PMID:26189811

  3. The DARPA compact superconducting x-ray lithography source features. [Defense Advanced Research Projects Agency (DARPA)

    SciTech Connect

    Heese, R. ); Kalsi, S. ); Leung, E. . Space Systems Div.)

    1991-01-01

    Under DARPA sponsorship, a compact Superconducting X-ray Lithography Source (SXLS) is being designed and built by the Brookhaven National Laboratory (BNL) with industry participation from Grumman Corporation and General Dynamics. This source is optimized for lithography work for sub-micron high density computer chips, and is about the size of a billiard table (1.5 m {times} 4.0 m). The machine has a racetrack configuration with two 180{degree} bending magnets being designed and built by General Dynamics under a subcontract with Grumman Corporation. The machine will have 18 photon ports which would deliver light peaked at a wave length of 10 Angstroms. Grumman is commercializing the SXLS device and plans to book orders for delivery of industrialized SXLS (ISXLS) versions in 1995. This paper will describe the major features of this device. The commercial machine will be equipped with a fully automated user-friendly control systems, major features of which are already working on a compact warm dipole ring at BNL. This ring has normal dipole magnets with dimensions identical to the SXLS device, and has been successfully commissioned. 4 figs., 1 tab.

  4. Compact electrostatic levitator for diffraction measurements with a two axis diffractometer and a laboratory x-ray source

    NASA Astrophysics Data System (ADS)

    Masaki, Tadahiko; Ishikawa, Takehiko; Paradis, Paul-François; Yoda, Shinichi; Okada, Junpei T.; Watanabe, Yasuhiro; Nanao, Susumu; Ishikura, Akiko; Higuchi, Kensuke; Mizuno, Akitoshi; Watanabe, Masato; Kohara, Shinji

    2007-02-01

    A compact electrostatic levitator was developed for the structural analysis of high-temperature liquids by x-ray diffraction methods. The size of the levitator was 200mm in diameter and 200mm in height and can be set up on a two axis diffractometer with a laboratory x-ray source, which is very convenient in performing structural measurements of high-temperature liquids. In particular, since the laboratory x-ray source allows a great amount of user time, preliminary or challenging experiments can be performed with trial and error, which prepares and complements synchrotron x-ray experiments. The present small apparatus also provides the advantage of portability and facility of setting. To demonstrate the capability of this electrostatic levitator, the static structure factors of alumina and silicon samples in their liquid phases were successfully measured.

  5. A compact tunable polarized X-ray source based on laser-plasma helical undulators.

    PubMed

    Luo, J; Chen, M; Zeng, M; Vieira, J; Yu, L L; Weng, S M; Silva, L O; Jaroszynski, D A; Sheng, Z M; Zhang, J

    2016-01-01

    Laser wakefield accelerators have great potential as the basis for next generation compact radiation sources because of their extremely high accelerating gradients. However, X-ray radiation from such devices still lacks tunability, especially of the intensity and polarization distributions. Here we propose a tunable polarized radiation source based on a helical plasma undulator in a plasma channel guided wakefield accelerator. When a laser pulse is initially incident with a skew angle relative to the channel axis, the laser and accelerated electrons experience collective spiral motions, which leads to elliptically polarized synchrotron-like radiation with flexible tunability on radiation intensity, spectra and polarization. We demonstrate that a radiation source with millimeter size and peak brilliance of 2 × 10(19) photons/s/mm(2)/mrad(2)/0.1% bandwidth can be made with moderate laser and electron beam parameters. This brilliance is comparable with third generation synchrotron radiation facilities running at similar photon energies, suggesting that laser plasma based radiation sources are promising for advanced applications. PMID:27377126

  6. A compact tunable polarized X-ray source based on laser-plasma helical undulators

    PubMed Central

    Luo, J.; Chen, M.; Zeng, M.; Vieira, J.; Yu, L. L.; Weng, S. M.; Silva, L. O.; Jaroszynski, D. A.; Sheng, Z. M.; Zhang, J.

    2016-01-01

    Laser wakefield accelerators have great potential as the basis for next generation compact radiation sources because of their extremely high accelerating gradients. However, X-ray radiation from such devices still lacks tunability, especially of the intensity and polarization distributions. Here we propose a tunable polarized radiation source based on a helical plasma undulator in a plasma channel guided wakefield accelerator. When a laser pulse is initially incident with a skew angle relative to the channel axis, the laser and accelerated electrons experience collective spiral motions, which leads to elliptically polarized synchrotron-like radiation with flexible tunability on radiation intensity, spectra and polarization. We demonstrate that a radiation source with millimeter size and peak brilliance of 2 × 1019 photons/s/mm2/mrad2/0.1% bandwidth can be made with moderate laser and electron beam parameters. This brilliance is comparable with third generation synchrotron radiation facilities running at similar photon energies, suggesting that laser plasma based radiation sources are promising for advanced applications. PMID:27377126

  7. R&D Toward a Compact High-Brilliance X-Ray Source Based on Channeling Radiation

    SciTech Connect

    Piot, P.; Brau, C.A.; Choi, B.K.; Gabella, W.E.; Jarvis, J.D.; Mendenhall, M.H.; Lewellen, J.W.; Mihalcea, D.; /Northern Illinois U.

    2012-08-01

    X-rays have been valuable to a large number of fields including Science, Medicine, and Security. Yet, the availability of a compact high-spectral brilliance X-ray sources is limited. A technique to produce X-rays with spectral brilliance B {approx} 10{sup 12} photons.(mm-mrd){sup -2}.(0.1% BW){sup -1} .s{sup -1} is discussed. The method is based on the generation and acceleration of a low-emittance field-emitted electron bunches. The bunches are then focused on a diamond crystal thereby producing channeling radiation. In this paper, after presenting the overarching concept, we discuss the generation, acceleration and transport of the low-emittance bunches with parameters consistent with the production of high-brilliance X-rays through channeling radiation. We especially consider the example of the Advanced Superconducting Test Accelerator (ASTA) currently in construction at Fermilab where a proof-of-principle experiment is in preparation.

  8. Compact tunable Compton x-ray source from laser-plasma accelerator and plasma mirror

    NASA Astrophysics Data System (ADS)

    Tsai, Hai-En; Wang, Xiaoming; Shaw, Joseph M.; Li, Zhengyan; Arefiev, Alexey V.; Zhang, Xi; Zgadzaj, Rafal; Henderson, Watson; Khudik, V.; Shvets, G.; Downer, M. C.

    2015-02-01

    We present an in-depth experimental-computational study of the parameters necessary to optimize a tunable, quasi-monoenergetic, efficient, low-background Compton backscattering (CBS) x-ray source that is based on the self-aligned combination of a laser-plasma accelerator (LPA) and a plasma mirror (PM). The main findings are (1) an LPA driven in the blowout regime by 30 TW, 30 fs laser pulses produce not only a high-quality, tunable, quasi-monoenergetic electron beam, but also a high-quality, relativistically intense (a0 ˜ 1) spent drive pulse that remains stable in profile and intensity over the LPA tuning range. (2) A thin plastic film near the gas jet exit retro-reflects the spent drive pulse efficiently into oncoming electrons to produce CBS x-rays without detectable bremsstrahlung background. Meanwhile, anomalous far-field divergence of the retro-reflected light demonstrates relativistic "denting" of the PM. Exploiting these optimized LPA and PM conditions, we demonstrate quasi-monoenergetic (50% FWHM energy spread), tunable (75-200 KeV) CBS x-rays, characteristics previously achieved only on more powerful laser systems by CBS of a split-off, counter-propagating pulse. Moreover, laser-to-x-ray photon conversion efficiency (˜6 × 10-12) exceeds that of any previous LPA-based quasi-monoenergetic Compton source. Particle-in-cell simulations agree well with the measurements.

  9. Development of a compact laser-produced plasma soft X-ray source for radiobiology experiments

    NASA Astrophysics Data System (ADS)

    Adjei, Daniel; Ayele, Mesfin Getachew; Wachulak, Przemyslaw; Bartnik, Andrzej; Wegrzynski, Łukasz; Fiedorowicz, Henryk; Vyšín, Luděk; Wiechec, Anna; Lekki, Janusz; Kwiatek, Wojciech M.; Pina, Ladislav; Davídková, Marie; Juha, Libor

    2015-12-01

    A desk-top laser-produced plasma (LPP) source of soft X-rays (SXR) has been developed for radiobiology research. The source is based on a double-stream gas puff target, irradiated with the focused beam of a commercial Nd:YAG laser. The source has been optimized to get a maximum photon emission from LPP in the X-ray "water window" spectral wavelength range from 2.3 nm (i.e., an absorption edge of oxygen) to 4.4 nm (i.e., an absorption edge of carbon) (280-540 eV in photon energy units) by using argon gas-puff target and spectral filtering by free-standing thin foils. The present source delivers nanosecond pulses of soft X-rays at a fluence of about 4.2 × 103 photons/μm2/pulse on a sample placed inside the vacuum chamber. In this paper, the source design, radiation output characterization measurements and initial irradiation experiments are described. The source can be useful in addressing observations related to biomolecular, cellular and organisms' sensitivity to pulsed radiation in the "water window", where carbon atoms absorb X-rays more strongly than the oxygen, mostly present in water. The combination of the SXR source and the radiobiology irradiation layout, reported in this article, make possible a systematic investigation of relationships between direct and indirect action of ionizing radiation, an increase of a local dose in carbon-rich compartments of the cell (e.g., lipid membranes), an experimental estimation of a particular role of the Auger effect (in particular in carbon atoms) in the damage to biological systems, and the study of ionization/excitation-density (LET - Linear Energy Transfer) and dose-rate effects in radiobiology.

  10. Compact hohlraum configuration with parallel planar-wire-array x-ray sources at the 1.7-MA Zebra generator.

    PubMed

    Kantsyrev, V L; Chuvatin, A S; Rudakov, L I; Velikovich, A L; Shrestha, I K; Esaulov, A A; Safronova, A S; Shlyaptseva, V V; Osborne, G C; Astanovitsky, A L; Weller, M E; Stafford, A; Schultz, K A; Cooper, M C; Cuneo, M E; Jones, B; Vesey, R A

    2014-12-01

    A compact Z-pinch x-ray hohlraum design with parallel-driven x-ray sources is experimentally demonstrated in a configuration with a central target and tailored shine shields at a 1.7-MA Zebra generator. Driving in parallel two magnetically decoupled compact double-planar-wire Z pinches has demonstrated the generation of synchronized x-ray bursts that correlated well in time with x-ray emission from a central reemission target. Good agreement between simulated and measured hohlraum radiation temperature of the central target is shown. The advantages of compact hohlraum design applications for multi-MA facilities are discussed.

  11. Compact tunable Compton x-ray source from laser-plasma accelerator and plasma mirror

    SciTech Connect

    Tsai, Hai-En; Wang, Xiaoming; Shaw, Joseph M.; Li, Zhengyan; Zgadzaj, Rafal; Henderson, Watson; Downer, M. C.; Arefiev, Alexey V.; Zhang, Xi; Khudik, V.; Shvets, G.

    2015-02-15

    We present an in-depth experimental-computational study of the parameters necessary to optimize a tunable, quasi-monoenergetic, efficient, low-background Compton backscattering (CBS) x-ray source that is based on the self-aligned combination of a laser-plasma accelerator (LPA) and a plasma mirror (PM). The main findings are (1) an LPA driven in the blowout regime by 30 TW, 30 fs laser pulses produce not only a high-quality, tunable, quasi-monoenergetic electron beam, but also a high-quality, relativistically intense (a{sub 0} ∼ 1) spent drive pulse that remains stable in profile and intensity over the LPA tuning range. (2) A thin plastic film near the gas jet exit retro-reflects the spent drive pulse efficiently into oncoming electrons to produce CBS x-rays without detectable bremsstrahlung background. Meanwhile, anomalous far-field divergence of the retro-reflected light demonstrates relativistic “denting” of the PM. Exploiting these optimized LPA and PM conditions, we demonstrate quasi-monoenergetic (50% FWHM energy spread), tunable (75–200 KeV) CBS x-rays, characteristics previously achieved only on more powerful laser systems by CBS of a split-off, counter-propagating pulse. Moreover, laser-to-x-ray photon conversion efficiency (∼6 × 10{sup −12}) exceeds that of any previous LPA-based quasi-monoenergetic Compton source. Particle-in-cell simulations agree well with the measurements.

  12. The Helios 1 compact superconducting storage ring x-ray source

    SciTech Connect

    Wilson, M.N; Smith, A.I.C.; Kempson, V.C.; Townsend, M.C.; Schouten, J.C.; Anderson, R.J.; Jorden, A.R.; Suller, V.P.; Poole, M.W.

    1993-05-01

    The basic properties of synchrotron radiation are described, the design of storage rings to produce synchrotron radiation is outlined, and the criteria for matching storage ring design to the needs of X-ray lithography are discussed. Simple scaling laws are presented showing the benefits for a storage ring of using the higher fields which superconducting magnets are able to provide. Helios 1 is a compact superconducting storage ring built by Oxford Instruments for installation at the IBM Advanced Lithography Facility (ALF). Design choices for superconducting rings are discussed, and the design and construction of Helios are described. Test results from the initial commissioning of Helios at Oxford are presented, but the main data on its performance when installed at ALF are given in another paper in this issue.

  13. Motionless electromagnetic phase stepping versus mechanical phase stepping in x-ray phase-contrast imaging with a compact source.

    PubMed

    Harmon, Katherine J; Miao, Houxun; Gomella, Andrew A; Bennett, Eric E; Foster, Barbara A; Bhandarkar, Priya; Wen, Han

    2015-04-21

    X-ray phase contrast imaging based on grating interferometers detects the refractive index distribution of an object without relying on radiation attenuation, thereby having the potential for reduced radiation absorption. These techniques belong to the broader category of optical wavefront measurement, which requires stepping the phase of the interference pattern to obtain a pixel-wise map of the phase distortion of the wavefront. While phase stepping traditionally involves mechanical scanning of a grating or mirror, we developed electromagnetic phase stepping (EPS) for imaging with compact sources to obviate the need for mechanical movement. In EPS a solenoid coil is placed outside the x-ray tube to shift its focal spot with a magnetic field, causing a relative movement between the projection of the sample and the interference pattern in the image. Here we present two embodiments of this method. We verified experimentally that electromagnetic and mechanical phase stepping give the same results and attain the same signal-to-noise ratios under the same radiation dose. We found that the relative changes of interference fringe visibility were within 3.0% when the x-ray focal spot was shifted by up to 1.0 mm in either direction. We conclude that when using x-ray tube sources, EPS is an effective means of phase stepping without the need for mechanical movement.

  14. X-ray spectra of galactic X-ray sources

    NASA Technical Reports Server (NTRS)

    Holt, S. S.

    1980-01-01

    The spectroscopic properties of the various classes of Galactic X-ray sources are discussed, with particular emphasis on binary sources containing an accreting compact object, where post-emission scattering in an accretion disk often prevents the initially produced X-radiation from being observed directly. Theoretical interpretations and X-ray observations are considered for the cataclysmic variables, binary systems with a white dwarf as the compact object and which suffer relatively less from Thomson scattering, and the similar phenomenological spectral characteristics of the bulge sources, including soft transients, bursters and steady X-ray sources with thermal spectra, thought to represent an accreting neutron star, are pointed out. The spectral characteristics of X-ray pulsars in accreting binary systems (rather than the Crab pulsar, which is losing rotational kinetic energy with time) are then presented and interpreted in terms of accretion in the polar regions, and mechanisms for the newly discovered X-ray emission from late-type RS CVn stars are considered.

  15. 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.

  16. 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.

  17. Compact X-pinch based point x-ray source for phase contrast imaging of inertial confinement fusion capsules

    SciTech Connect

    Beg, F. N.; Stephens, R. B.; Xu, H.-W.; Haas, D.; Eddinger, S.; Tynan, G.; Shipton, E.; DeBono, B.; Wagshal, K.

    2006-09-04

    Results from experiments performed to characterize plastic capsules containing foam layers are presented. A compact X-pinch pulser with a footprint <1 m{sup 2} having a peak current of 80 kA and a rise time of 50 ns was used. Various wire materials including tungsten, molybdenum, and aluminum were employed. Results with plastic capsules (1 mm diameter, 20 {mu}m thick wall with 80 {mu}m foam inside the capsule) show phase contrast effects at the edges of the wall due to the foam, which mimics the ice inside the shell. The sharpness of the image reveals a source less than 2 {mu}m in size and x-ray diodes show a pulse length of {approx}10 ns. The small source size allows high-resolution phase contrast imaging of capsules. The x-ray pulse from an X-pinch is sufficiently short to avoid the motional blurring due to cryogenic system vibrations, which is not possible with low flux sources.

  18. 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.

  19. A compact source of intense 1-100 keV monochromatic X-rays from low energy protons

    NASA Astrophysics Data System (ADS)

    Arduini, G.; Cicardi, C.; Milazzo, M.; Sangaletti, L.; Silari, M.

    1995-05-01

    The properties and possible applications of a very intense source of monochromatic X-rays, tunable in the 1-100 keV range, obtained by coupling a low energy (2-4 MeV) high current proton accelerator with an irradiation chamber provided with a multiple target system and collimator are discussed. The properties of the source are presented in terms of intensity, monochromaticity, polarizability and time structure. Fields where such a source can be employed are discussed, namely PIXE-induced XRF, X-ray photoemission spectroscopy, generation of soft X-rays, radiographic applications in archeometry and medical radiography with monoenergetic radiation.

  20. Extreme ultraviolet and soft X-ray imaging with compact, table top laser plasma EUV and SXR sources

    NASA Astrophysics Data System (ADS)

    Wachulak, P. W.; Bartnik, A.; Kostecki, J.; Wegrzynski, L.; Fok, T.; Jarocki, R.; Szczurek, M.; Fiedorowicz, H.

    2015-12-01

    We present a few examples of imaging experiments, which were possible using a compact laser-plasma extreme ultraviolet (EUV) and soft X-ray (SXR) source, based on a double stream gas puff target. This debris-free source was used in full-field EUV imaging to obtain magnified images of test samples, ZnO nanofibers and images of the membranes coated with salt crystals. The source was also employed for SXR microscopy in the "water-window" spectral range using grazing incidence Wolter type-I objective to image test samples and to perform the initial studies of biological objects. Gas puff target EUV source, spectrally tuned for 13.5 nm wavelength with multilayer mirror and thin film filters, was also used in variety of shadowgraphy experiments to study the density of newly developed modulated density gas puff targets. Finally, the source was also employed in EUV tomography experiments of low density objects with the goal to measure and optimize the density of the targets dedicated to high harmonic generation.

  1. Final report of LDRD project : compact ultrabright multikilovolt x-ray sources for advanced materials studies, 3D nanoimaging, and attosecond x-ray technology.

    SciTech Connect

    Loubriel, Guillermo Manuel; Rhodes, Charles Kirkham; Mar, Alan

    2005-02-01

    Experimental evidence and corresponding theoretical analyses have led to the conclusion that the system composed of Xe hollow atom states, that produce a characteristic Xe(L) spontaneous emission spectrum at 1 {at} 2.9 {angstrom} and arise from the excitation of Xe clusters with an intense pulse of 248 nm radiation propagating in a self-trapped plasma channel, closely represents the ideal situation sought for amplification in the multikilovolt region. The key innovation that is central to all aspects of the proposed work is the controlled compression of power to the level ({approx} 10{sup 20} W/cm{sup 3}) corresponding to the maximum achieved by thermonuclear events. Furthermore, since the x-ray power that is produced appears in a coherent form, an entirely new domain of physical interaction is encountered that involves states of matter that are both highly excited and highly ordered. Moreover, these findings lead to the concept of 'photonstaging', an idea which offers the possibility of advancing the power compression by an additional factor of {approx} 10{sup 9} to {approx} 10{sup 29} W/cm{sup 3}. In this completely unexplored regime, g-ray production ({h_bar}{omega}{sub {gamma}} {approx} 1 MeV) is expected to be a leading process. A new technology for the production of very highly penetrating radiation would then be available. The Xe(L) source at {h_bar}{omega}{sub x} {approx} 4.5 keV can be applied immediately to the experimental study of many aspects of the coupling of intense femtosecond x-ray pulses to materials. In a joint collaboration, the UIC group and Sandia plan to explore the following areas. These are specifically, (1) anomalous electromagnetic coupling to solid state materials, (2) 3D nanoimaging of solid matter and hydrated biological materials (e.g. interchromosomal linkers and actin filaments in muscle), and (3) EMP generation with attosecond x-rays.

  2. 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.

  3. Tsinghua Thomson scattering X-ray source

    NASA Astrophysics Data System (ADS)

    Tang, Chuanxiang; Huang, Wenhui; Li, Renkai; Du, Yingchao; Yan, Lixin; Shi, Jiaru; Du, Qiang; Yu, Peicheng; Chen, Huaibi; Du, Taibin; Cheng, Cheng; Lin, Yuzheng

    2009-09-01

    We proposed the Tsinghua Thomson scattering X-ray (TTX) source as an ultra-fast, high flux source for advanced X-ray imaging studies and applications. A linac system, which consists of an S-band photocathode RF gun, a SLAC type 3 m traveling wave tube and two X-band structures, generates ultra-short, high brightness electron pulses to scatter with tera-watt femto-second laser pulses. A compact low energy electron storage ring is also designed to dramatically enhance the average X-ray flux. In this paper, we present the simulation studies and optimized parameters of the electron and X-ray pulses. The construction and commissioning status of TTX is also reported.

  4. 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.

  5. 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.

  6. 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.

  7. Ultrafast X-ray Sources

    SciTech Connect

    George Neil

    2010-04-19

    Since before the scattering of X-rays off of DNA led to the first understanding of the double helix structure, sources of X-rays have been an essential tool for scientists examining the structure and interactions of matter. The resolution of a microscope is proportional to the wavelength of light so x-rays can see much finer structures than visible light, down to single atoms. In addition, the energy of X-rays is resonant with the core atomic levels of atoms so with appropriate wavelengths the placement of specific atoms in a large molecule can be determined. Over 10,000 scientists use synchrotron sources, storage rings of high energy electrons, each year worldwide. As an example of such use, virtually every picture of a protein or drug molecule that one sees in the scientific press is a reconstruction based on X-ray scattering of synchrotron light from the crystallized form of that molecule. Unfortunately those pictures are static and proteins work through configuration (shape) changes in response to energy transfer. To understand how biological systems work requires following the energy flow to these molecules and tracking how shape changes drive their interaction with other molecules. We'd like to be able to freeze the action of these molecules at various steps along the way with an X-ray strobe light. How fast does it have to be? To actually get a picture of a molecule in a fixed configuration requires X-ray pulses as short as 30 femtoseconds (1/30 of a millionth of a millionth of a second). To capture the energy flow through changes in electronic levels requires a faster strobe, less than 1 femtosecond! And to acquire such information in smaller samples with higher accuracy demands brighter and brighter X-rays. Unfortunately modern synchrotrons (dubbed 3rd Generation Light Sources) cannot deliver such short bright pulses of X-rays. An entirely new approach is required, linear-accelerator (linac-)-based light sources termed 4th or Next Generation Light Sources

  8. X-RAY EMISSION FROM HESS J1731-347/SNR G353.6-0.7 AND CENTRAL COMPACT SOURCE XMMS J173203-344518

    SciTech Connect

    Tian, W. W.; Li, Z.; Leahy, D. A.; Yang, J.; Lu, D.; Yang, X. J.; Yamazaki, R. E-mail: wtian@ucalgary.c

    2010-04-01

    We present new results of the HESS J1731-347/SNR G353.6-0.7 system from XMM-Newton and Suzaku X-ray observations and Delinha CO observations. We discover extended hard X-rays coincident with the bright, extended TeV source HESS J1731-347 and the shell of the radio supernova remnant (SNR). We find that spatially resolved X-ray spectra can generally be characterized by an absorbed power-law model, with a photon index of {approx}2, typical of non-thermal emission. A bright X-ray compact source, XMMS J173203-344518, is also detected near the center of the SNR. We find no evidence of a radio counterpart or an extended X-ray morphology for this source, making it unlikely to be a pulsar wind nebular (PWN). The spectrum of the source can be well fitted by an absorbed blackbody with a temperature of {approx}0.5 keV plus a power-law tail with a photon index of {approx}5, reminiscent of the X-ray emission of a magnetar. CO observations toward the inner part of the High Energy Stereoscopic System (HESS) source reveal a bright cloud component at -20 +- 4 km s{sup -1}, which is likely located at the same distance of {approx}3.2 kpc as the SNR. Based on the probable association between the X-ray and gamma-ray emissions and likely association between the CO cloud and the SNR, we argue that the extended TeV emission originates from the interaction between the SNR shock and the adjacent CO clouds rather than from a PWN.

  9. X-Ray Emission from HESS J1731-347/SNR G353.6-0.7 and Central Compact Source XMMS J173203-344518

    NASA Astrophysics Data System (ADS)

    Tian, W. W.; Li, Z.; Leahy, D. A.; Yang, J.; Yang, X. J.; Yamazaki, R.; Lu, D.

    2010-04-01

    We present new results of the HESS J1731-347/SNR G353.6-0.7 system from XMM-Newton and Suzaku X-ray observations and Delinha CO observations. We discover extended hard X-rays coincident with the bright, extended TeV source HESS J1731-347 and the shell of the radio supernova remnant (SNR). We find that spatially resolved X-ray spectra can generally be characterized by an absorbed power-law model, with a photon index of ~2, typical of non-thermal emission. A bright X-ray compact source, XMMS J173203-344518, is also detected near the center of the SNR. We find no evidence of a radio counterpart or an extended X-ray morphology for this source, making it unlikely to be a pulsar wind nebular (PWN). The spectrum of the source can be well fitted by an absorbed blackbody with a temperature of ~0.5 keV plus a power-law tail with a photon index of ~5, reminiscent of the X-ray emission of a magnetar. CO observations toward the inner part of the High Energy Stereoscopic System (HESS) source reveal a bright cloud component at -20 ± 4 km s-1, which is likely located at the same distance of ~3.2 kpc as the SNR. Based on the probable association between the X-ray and γ-ray emissions and likely association between the CO cloud and the SNR, we argue that the extended TeV emission originates from the interaction between the SNR shock and the adjacent CO clouds rather than from a PWN.

  10. 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.

  11. 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.

  12. U-shape rotating anti-cathode compact X-ray generator: 20 times stronger than the commercially available X-ray source.

    PubMed

    Sakabe, N; Sakabe, K; Ohsawa, S; Sakai, T; Kobayakawa, H; Sugimura, T; Ikeda, M; Tawada, M; Watanabe, N; Sasaki, K; Wakatsuki, M

    2013-11-01

    A new type of U-shape anti-cathode X-ray generator in which the inner surface of a cylindrical target is irradiated by an electron beam has been made by modifying a conventional rotating anti-cathode X-ray generator whose brightness in the catalog is 12 kW mm(-2). The target material (Cu), target radius (50 mm) and rotating speed (6,000 r.p.m.) were not changed in this modification. A brightness of 52 kW mm(-2) was obtained by this U-shape-type X-ray generator. This means that the brightness of the new type is 4.3 times greater than that of the old unmodified one. Furthermore, the new-type X-ray generator yielded a brightness of 129 kW mm(-2) by adding a carbon coating on the Cu target. This means an overall increase of brightness of ten times. The original generator has the highest brightness in the generators of the same class (having a radius of 50 mm and rotation speed of 6,000 r.p.m.). Observations showed that Cu Kα counts at vertical incidence of the electron beam onto the surface of the new target, which is initially optically smooth, decrease as the surface is roughened by a severe thermal stress caused by strong electron beam exposure. Further observation reveals, however, that oblique incidence of the electron beam onto the roughened surface drastically increased the X-ray output and amounts to twice as much as that from a smooth surface at vertical incidence. Thus, at the present stage, an overall increase of brightness has been realised at a level 20 times stronger than that of the original commercially offered X-ray generator that we modified.

  13. ROSAT: X ray survey of compact groups

    NASA Technical Reports Server (NTRS)

    Vangorkom, Jacqueline

    1993-01-01

    This is the final technical report on grant NAG5-1954, which was awarded under the NASA ROSAT Guest Investigator Program to Columbia University. This grant was awarded for a number of projects on two rather different topics: (1) an x-ray survey of compact groups of galaxies; and (2) the fate of gas in merging galaxies. Progress made in these projects is presented.

  14. K-edge imaging with quasi-monochromatic LCS X-ray source on the basis of S-band compact electron linac

    NASA Astrophysics Data System (ADS)

    Kuroda, R.; Taira, Y.; Yasumoto, M.; Toyokawa, H.; Yamada, K.

    2014-07-01

    A quasi-monochromatic hard X-ray source via laser Compton scattering (LCS) was developed on the basis of an S-band compact electron linac at AIST. The total number of photons generated and the maximum X-ray energy were ∼107 photons/s and 41 keV, respectively, when a 42-MeV electron beam was collided with an 800-nm Ti:sapphire laser at a 15° collision angle. We successfully demonstrated K-edge imaging using these LCS X-rays for the high-contrast observation of a human phantom with barium sulfate-concentrated blood vessels. In this paper, we describe the results of the K-edge imaging and analytical estimates of the contrast enhancement effect for the energy range ∼37 keV, which corresponds to the K-edge energy of barium.

  15. In-line phase-contrast imaging of a biological specimen using a compact laser-Compton scattering-based x-ray source

    SciTech Connect

    Ikeura-Sekiguchi, H.; Kuroda, R.; Yasumoto, M.; Toyokawa, H.; Koike, M.; Yamada, K.; Sakai, F.; Mori, K.; Maruyama, K.; Oka, H.; Kimata, T.

    2008-03-31

    Laser-Compton scattering (LCS) x-ray sources have recently attracted much attention for their potential use at local medical facilities because they can produce ultrashort pulsed, high-brilliance, and quasimonochromatic hard x rays with a small source size. The feasibility of in-line phase-contrast imaging for a 'thick' biological specimens of rat lumbar vertebrae using the developed compact LCS-X in AIST was investigated for the promotion of clinical imaging. In the higher-quality images, anatomical details of the spinous processes of the vertebrae are more clearly observable than with conventional absorption radiography. The results demonstrate that phase-contrast radiography can be performed using LCS-X.

  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. A compact, sample-in-atmospheric-pressure soft x-ray microscope developed at Pohang Light Source

    NASA Astrophysics Data System (ADS)

    Lim, Jun; Shin, Hyun-Joon; Chae, Keun Hwa; Hwang, Chan-Cuk; Hwang, Han-Na; Hong, Chung Ki

    2010-06-01

    A full-field transmission soft x-ray microscope (TXM) was developed at the Pohang Light Source. With a 2 mm diameter condenser zone plate and a 40 nm outermost-zone-width objective zone plate, the TXM's achieved spatial resolution is better than 50 nm at the photon energy of 500 eV (wavelength: 2.49 nm). The TXM is portable and mounted in tandem with a 7B1 spectroscopy end station. The sample position is outside the vacuum, allowing for quick sample changes and enhanced in situ experimental capability. In addition, the TXM is pinhole-free and easy to align, having commercial mounts located outside the vacuum components.

  18. A compact, sample-in-atmospheric-pressure soft x-ray microscope developed at Pohang Light Source.

    PubMed

    Lim, Jun; Shin, Hyun-Joon; Chae, Keun Hwa; Hwang, Chan-Cuk; Hwang, Han-Na; Hong, Chung Ki

    2010-06-01

    A full-field transmission soft x-ray microscope (TXM) was developed at the Pohang Light Source. With a 2 mm diameter condenser zone plate and a 40 nm outermost-zone-width objective zone plate, the TXM's achieved spatial resolution is better than 50 nm at the photon energy of 500 eV (wavelength: 2.49 nm). The TXM is portable and mounted in tandem with a 7B1 spectroscopy end station. The sample position is outside the vacuum, allowing for quick sample changes and enhanced in situ experimental capability. In addition, the TXM is pinhole-free and easy to align, having commercial mounts located outside the vacuum components. PMID:20590241

  19. A compact, sample-in-atmospheric-pressure soft x-ray microscope developed at Pohang Light Source

    SciTech Connect

    Lim, Jun; Shin, Hyun-Joon; Chae, Keun Hwa; Hwang, Chan-Cuk; Hwang, Han-Na; Hong, Chung Ki

    2010-06-15

    A full-field transmission soft x-ray microscope (TXM) was developed at the Pohang Light Source. With a 2 mm diameter condenser zone plate and a 40 nm outermost-zone-width objective zone plate, the TXM's achieved spatial resolution is better than 50 nm at the photon energy of 500 eV (wavelength: 2.49 nm). The TXM is portable and mounted in tandem with a 7B1 spectroscopy end station. The sample position is outside the vacuum, allowing for quick sample changes and enhanced in situ experimental capability. In addition, the TXM is pinhole-free and easy to align, having commercial mounts located outside the vacuum components.

  20. X-ray reflectivity imager with 15 W power X-ray source

    NASA Astrophysics Data System (ADS)

    Jiang, Jinxing; Sakurai, Kenji

    2016-09-01

    X-ray reflectivity is usually used for the routine analysis of layered structures of uniform thin films. So far, the technique has some limitations in the application to more practical inhomogeneous/patterned samples. X-ray reflectivity imaging is recently developed technique and can give the reconstructed image from many X-ray reflection projections. The present article gives the instrumental details of the compact X-ray reflectivity imager. Though the power of X-ray source is only 15 W, it works well. The calibration of the system has been discussed, because it is particularly important for the present grazing incidence geometry. We also give a visualization example of the buried interface, physical meaning of the reconstructed image, and discussions about possibilities for improvement.

  1. Ultraluminous X-ray Sources

    NASA Astrophysics Data System (ADS)

    Gladstone, Jeanette

    2012-07-01

    The first black hole was observed almost 50 years ago, ˜ 1 year after Sco X-1 (although its nature was not confirmed for ˜ 11 years). Observations of black holes have been ongoing since then, falling in to two distinct categories; stellar-mass (sMBHs; 3 - 80 M_{⊙}) and super-massive black holes (10^6 - 10^9 M_⊙). The missing link between these two types, intermediate mass black holes, has been the target of many searches due to their cosmological implications. Ultraluminous X-ray sources (ULXs) have been proposed to harbor such objects, but recent observational evidence has strongly suggested that the majority contain sMBHs. However, a handful of the brightest ULXs are so luminous that they defy this explanation. Here we will discuss the nature of both standard ULXs and this new bright subgroup of this population.

  2. AN X-RAY COOLING-CORE CLUSTER SURROUNDING A LOW-POWER COMPACT STEEP SPECTRUM RADIO SOURCE 1321+045

    SciTech Connect

    Kunert-Bajraszewska, M.; Siemiginowska, A.; Labiano, A.

    2013-07-20

    We discovered an X-ray cluster in a Chandra observation of the compact steep spectrum (CSS) radio source 1321+045 (z = 0.263). CSS sources are thought to be young radio objects at the beginning of their evolution and can potentially test the cluster heating process. 1321+045 is a relatively low-luminosity source and its morphology consists of two radio lobes on the opposite sides of a radio core with no evidence for jets or hotspots. The optical emission line ratios are consistent with an interstellar medium dominated by active galactic nucleus photoionization with a small contribution from star formation, and no contributions from shocks. Based on these ratios, we classify 1321+045 as a low excitation galaxy (LEG) and suggest that its radioactivity is in a coasting phase. The X-ray emission associated with the radio source is detected with 36.1 {+-} 8.3 counts, but the origin of this emission is highly uncertain. The current X-ray image of the cluster does not show any signatures of a radio source impact on the cluster medium. Chandra detects the cluster emission at >3{sigma} level out to {approx}60'' (240 kpc). We obtain the best-fit beta model parameters of the surface brightness profile of {beta} = 0.58 {+-} 0.2 and a core radius of 9.4{sup +1.1}{sub -0.9} arcsec. The average temperature of the cluster is equal to kT = 4.4{sup +0.5}{sub -0.3} keV, with a temperature and cooling profile indicative of a cooling core. We measure the cluster luminosity L{sub (0.5-2{sub keV)}} = 3 Multiplication-Sign 10{sup 44} erg s{sup -1} and mass 1.5 Multiplication-Sign 10{sup 14} M{sub Sun}.

  3. A compact x-ray free electron laser

    SciTech Connect

    Barletta, W.; Attac, M.; Cline, D.B.; Kolonko, J.; Wang, X.; Bhowmik, A.; Bobbs, B.; Cover, R.A.; Dixon, F.P.; Rakowsky, G.; Gallardo, J.; Pellegrini, C.; Westenskow, G.

    1988-09-09

    We present a design concept and simulation of the performance of a compact x-ray, free electron laser driven by ultra-high gradient rf-linacs. The accelerator design is based on recent advances in high gradient technology by a LLNL/SLAC/LBL collaboration and on the development of bright, high current electron sources by BNL and LANL. The GeV electron beams generated with such accelerators can be concerted to soft x-rays in the range from 2--10 nm by passage through short period, high fields strength wigglers as are being designed at Rocketdyne. Linear light sources of this type can produce trains of picosecond (or shorter) pulses of extremely high spectral brilliance suitable for flash holography of biological specimens in vivo and for studies of fast chemical reactions. 12 refs., 8 figs., 4 tabs.

  4. Circinus X-1: a Laboratory for Studying the Accretion Phenomenon in Compact Binary X-Ray Sources. Ph.D. Thesis - Maryland Univ.

    NASA Technical Reports Server (NTRS)

    Robinson-Saba, J. L.

    1983-01-01

    Observations of the binary X-ray source Circinus X-1 provide samples of a range of spectral and temporal behavior whose variety is thought to reflect a broad continuum of accretion conditions in an eccentric binary system. The data support an identification of three or more X-ray spectral components, probably associated with distinct emission regions.

  5. 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.

  6. Globular cluster x-ray sources.

    PubMed

    Pooley, David

    2010-04-20

    Globular clusters and x-ray astronomy have a long and fruitful history. Uhuru and OSO-7 revealed highly luminous (> 10(36) ergs(-1)) x-ray sources in globular clusters, and Einstein and ROSAT revealed a larger population of low-luminosity (< 10(33) 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.

  7. 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

  8. Infrared studies of galactic center x-ray sources

    NASA Astrophysics Data System (ADS)

    DeWitt, Curtis

    -type supergiant at an distance of 3.7 kpc; and an O star at the Galactic Center distance. I also identified 3 foreground X-ray source counterparts within a distance of 1 kpc which do not show obvious emission features in their spectra. However, on the basis of the low surface density of unreddened sources along the line-of-sight to the Galactic Center and our previous statistical analysis (DeWitt et al., 2010), these can be securely identified as the true counterparts to their coincident X-ray point sources. Lastly, I used the results of my matching simulations to infer the presence of 7+/-2 true counterparts within a set of late type giants that I observed without detectable emission features. I conclude from this work that the probable excess in red giant X-ray counterparts without emission lines needs to be confirmed both with larger samples of spectroscopically surveyed counterparts and more advanced statistical simulations of the match authenticity. Also, the nature of the compact object in two of my counterpart discoveries, the Be HMXB and the symbiotic binary, can be strongly constrained with X-ray spectral fitting. Lastly, I conclude that spectroscopic surveys for new X-ray source counterparts in the GC may be able to increase their efficiency by specifically targeting photometric variables and very close astrometric matches of IR/X-ray sources.

  9. Development of a kilowatt-class, joule-level ultrafast laser for driving compact high average power coherent EUV/soft x-ray sources

    NASA Astrophysics Data System (ADS)

    Reagan, Brendan A.; Baumgarten, Cory M.; Pedicone, Michael A.; Bravo, Herman; Yin, Liang; Woolston, Mark; Wang, Hanchen; Menoni, Carmen S.; Rocca, Jorge J.

    2016-03-01

    Our recent progress in the development of high energy / high average power, chirped pulse amplification laser systems based on diode-pumped, cryogenically-cooled Yb:YAG amplifiers is discussed, including the demonstration of a laser that produces 1 Joule, sub-10 picosecond duration, λ = 1.03μm pulses at 500 Hz repetition rate. This compact, all-diodepumped laser combines a mode-locked Yb:KYW oscillator and a water-cooled Yb:YAG preamplifer with two cryogenic power amplification stages to produce 1.5 Joule pulses with high beam quality which are subsequently compressed. This laser system occupies an optical table area of less than 1.5x3m2. This laser was employed to pump plasma-based soft x-ray lasers at λ = 10-20nm at repetition rates >=100 Hz. To accomplish this, temporally-shaped pulses were focused at grazing incidence into a high aspect ratio line focus using cylindrical optics on a high shot capacity rotating metal target. This results in an elongated plasma amplifier that produces microjoule pulses at several narrow-linewidth EUV wavelengths between λ = 109Å and 189Å. The resulting fraction of a milliwatt average powers are the highest reported to date for a compact, coherent source operating at these wavelengths, to the best of our knowledge.

  10. 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)

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Generation of circularly polarized radiation from a compact plasma-based extreme ultraviolet light source for tabletop X-ray magnetic circular dichroism studies.

    PubMed

    Wilson, Daniel; Rudolf, Denis; Weier, Christian; Adam, Roman; Winkler, Gerrit; Frömter, Robert; Danylyuk, Serhiy; Bergmann, Klaus; Grützmacher, Detlev; Schneider, Claus M; Juschkin, Larissa

    2014-10-01

    Generation of circularly polarized light in the extreme ultraviolet (EUV) spectral region (about 25 eV-250 eV) is highly desirable for applications in spectroscopy and microscopy but very challenging to achieve in a small-scale laboratory. We present a compact apparatus for generation of linearly and circularly polarized EUV radiation from a gas-discharge plasma light source between 50 eV and 70 eV photon energy. In this spectral range, the 3p absorption edges of Fe (54 eV), Co (60 eV), and Ni (67 eV) offer a high magnetic contrast often employed for magneto-optical and electron spectroscopy as well as for magnetic imaging. We simulated and designed an instrument for generation of linearly and circularly polarized EUV radiation and performed polarimetric measurements of the degree of linear and circular polarization. Furthermore, we demonstrate first measurements of the X-ray magnetic circular dichroism at the Co 3p absorption edge with a plasma-based EUV light source. Our approach opens the door for laboratory-based, element-selective spectroscopy of magnetic materials and spectro-microscopy of ferromagnetic domains. PMID:25362374

  17. Generation of circularly polarized radiation from a compact plasma-based extreme ultraviolet light source for tabletop X-ray magnetic circular dichroism studies

    SciTech Connect

    Wilson, Daniel; Rudolf, Denis Juschkin, Larissa; Weier, Christian; Adam, Roman; Schneider, Claus M.; Winkler, Gerrit; Frömter, Robert; Danylyuk, Serhiy; Bergmann, Klaus; Grützmacher, Detlev

    2014-10-15

    Generation of circularly polarized light in the extreme ultraviolet (EUV) spectral region (about 25 eV–250 eV) is highly desirable for applications in spectroscopy and microscopy but very challenging to achieve in a small-scale laboratory. We present a compact apparatus for generation of linearly and circularly polarized EUV radiation from a gas-discharge plasma light source between 50 eV and 70 eV photon energy. In this spectral range, the 3p absorption edges of Fe (54 eV), Co (60 eV), and Ni (67 eV) offer a high magnetic contrast often employed for magneto-optical and electron spectroscopy as well as for magnetic imaging. We simulated and designed an instrument for generation of linearly and circularly polarized EUV radiation and performed polarimetric measurements of the degree of linear and circular polarization. Furthermore, we demonstrate first measurements of the X-ray magnetic circular dichroism at the Co 3p absorption edge with a plasma-based EUV light source. Our approach opens the door for laboratory-based, element-selective spectroscopy of magnetic materials and spectro-microscopy of ferromagnetic domains.

  18. A compact X-ray lithography lattice using superferric magnets

    NASA Astrophysics Data System (ADS)

    Swenson, C. A.; Huson, F. R.; Mackay, W. W.; Chen, L. K.; Ohnuma, S.

    A conceptual lattice design for a very compact superconducting synchrotron dedicated to X-ray lithography is presented. The synchrotron radiation produced in the high field superconducting magnets has a critical wavelength of 10 angstrom at a beam energy of about 787 MeV. The size and angular divergence of the beam in this lattice can satisfy future requirements for X-ray lithography. An optimization of the lithography parameters is presented.

  19. 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.

  20. 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

  1. 1 kHz tabletop ultrashort hard x-ray source for time-resolved x-ray protein crystallography

    NASA Astrophysics Data System (ADS)

    Bonvalet, Adeline; Darmon, Adeline; Lambry, Jean-Christophe; Martin, Jean-Louis; Audebert, Patrick

    2006-09-01

    We describe a compact, reliable, and high-average-power femtosecond x-ray source and its first application to diffraction on protein crystal. The setup relies on a homemade Ti: sapphire system delivering 12 mJ at a 1 kHz repetition rate, associated with a small vacuum chamber especially designed for laser-plasma interaction and x-ray applications. This device allows the generation of 5×109 photons/s/sr at 8 keV and optimized x-ray irradiation of the studied sample, which can be placed close to the source. We present the diffraction pattern of a protein crystal in a divergent beam geometry, which is a first step to a subpicosecond x-ray diffraction experiment.

  2. Sensitivity in X-ray grating interferometry on compact systems

    SciTech Connect

    Thuering, Thomas; Modregger, Peter; Haemmerle, Stefan; Weiss, Stephan; Nueesch, Joachim; Stampanoni, Marco

    2012-07-31

    The optimization of compact X-ray grating interferometry systems is crucial for the progress of this technique in industrial devices. Here, an analytical formulation for the sensitivity of the phase contrast image acquisition is derived using previous results from noise analyses. Furthermore, experimental measurements of the sensitivity for different configurations are compared, providing further insight into the dependence on polychromatic radiation. Finally, strategies for the geometrical optimization are given.

  3. 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.

  4. 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

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

    DOE PAGES

    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

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. Observation of living cells by x-ray microscopy with a laser-plasma x-ray source

    NASA Astrophysics Data System (ADS)

    Tomie, Toshihisa; Shimizu, Hazime; Majima, Toshikazu; Yamada, Mitsuo; Kanayama, Toshihiko; Yano, M.; Kondo, H.

    1991-12-01

    We studied laser-produced plasma as an x-ray source for x-ray microscopy. Using water- window x rays, contact x-ray images of living sea urchin sperm were taken by a 500 picosecond x-ray pulse. The resist relief was examined by atomic force microscope and informations characteristic of x-ray microscopy were obtained. The finest feature noticed in the x-ray image was 0.1 micrometers .

  12. S-band linac-based X-ray source with π/2-mode electron linac

    NASA Astrophysics Data System (ADS)

    Deshpande, Abhay; Araki, Sakae; Dixit, Tanuja; Fukuda, Masafumi; Krishnan, R.; Pethe, Sanjay; Sakaue, Kazuyuki; Terunuma, Nobuhiro; Urakawa, Junji; Washio, Masakazu

    2011-05-01

    The activities with the compact X-ray source are attracting more attention, particularly for the applications of the source in medical fields. We propose the fabrication of a compact X-ray source using the SAMEER electron linear accelerator and the KEK laser undulator X-ray source (LUCX) technologies. The linac developed at SAMEER is a standing wave side-coupled S-band linac operating in the π/2 mode. In the proposed system, a photocathode RF gun will inject bunches of electrons in the linac to accelerate and achieve a high-energy, low-emittance beam. This beam will then interact with the laser in the laser cavity to produce X-rays of a type well suited for various applications. The side-coupled structure will make the system more compact, and the π/2 mode of operation will enable a high repetition rate operation, which will help to increase the X-ray yield.

  13. Hard cosmic X-ray sources.

    NASA Technical Reports Server (NTRS)

    Peterson, L. E.

    1973-01-01

    A review of the observational status of X-ray sources detected in the 20 to 500 keV range is presented. Of the approximately 115 sources listed in the March 1972 edition of the UHURU 2-6 keV sky survey catalog, about 15 sources have been studied in hard X rays. Most of the data have been obtained from balloons, although the OSO-3, and more recently the OSO-7, have contributed. With the exception of CEN A, the SMC, and possibly M-87, all the sources detected at higher energies are galactic and heavily concentrated in the galactic plane. The Crab Nebula has been measured to about 500 keV in continuous emission and a component at the 33-msec pulsar period comprising about 20% of the total emission has been detected to 10 MeV. Objects such as SCO-1 and CYG-2 are characterized by an exponential spectrum, which varies over a 10-min time scale about a factor of two, and a flatter spectrum extending to above 40 keV which exhibits independent variability.

  14. Optical characteristics of young quasars as sources of the cosmic X-ray background

    NASA Technical Reports Server (NTRS)

    Boldt, E.; Leiter, D.

    1983-01-01

    The sources which dominate the thermal cosmic X-ray background cannot have X-ray spectra similar to the power laws measured for bright active galactic nuclei. The optical consequences of this disparity are pursued by considering a standard model for the photoexcitation and heating of the line emitting gas surrounding a central source (e.g., such as a quasar). The optical line emission to be associated with compact young quasar sources having the same X-ray spectrum as the X-ray background is found to be substantially different from that characteristic of typical quasars. Implications on quasar source counts and the identification of such new objects are discussed.

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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

  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. 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.

  4. Low-luminosity X-ray sources and the Galactic ridge X-ray emission

    NASA Astrophysics Data System (ADS)

    Warwick, R.

    2014-07-01

    We make a new determination of the hard-band (2-10 keV) X-ray luminosity function (XLF) of relative low-luminosity Galactic X-ray sources based on a source sample derived from the XMM Slew Survey (XSS). The source population is comprised of coronally-active late-type stars and binaries with hard-band X-ray luminosities in the range 10^{28-32} erg s^{-1} and cataclysmic variables (magnetic and non-magnetic) with X-ray luminosities spanning the range 10^{30-34} erg s^{-1}. We use this new estimate of the XLF, to predict the 2-10 keV X-ray source counts on the Galactic Plane at faint fluxes and show that the result is fully consistent with the available observational constraints. Similarly the predicted surface brightness, both in the full 2-10 keV band and in a restricted 6-10 keV bandpass, due to the integrated emission of faint unresolved Galactic sources, is well matched to the observed intensity of the Galactic ridge X-ray emission (GRXE). We find that the coronally-active sources make the dominant contribution to both the faint Galactic X-ray source counts and the GRXE.

  5. 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.

  6. 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.

  7. The Chandra planetary nebula survey (CHANPLANS). II. X-ray emission from compact planetary nebulae

    SciTech Connect

    Freeman, M.; Kastner, J. H.; Montez, R. Jr.; Balick, B.; Frew, D. J.; De Marco, O.; Parker, Q. A.; Jones, D.; Miszalski, B.; Sahai, R.; Blackman, E.; Frank, A.; Chu, Y.-H.; Guerrero, M. A.; Zijlstra, A.; Bujarrabal, V.; Corradi, R. L. M.; Nordhaus, J.; and others

    2014-10-20

    We present results from the most recent set of observations obtained as part of the Chandra X-ray observatory Planetary Nebula Survey (CHANPLANS), the first comprehensive X-ray survey of planetary nebulae (PNe) in the solar neighborhood (i.e., within ∼1.5 kpc of the Sun). The survey is designed to place constraints on the frequency of appearance and range of X-ray spectral characteristics of X-ray-emitting PN central stars and the evolutionary timescales of wind-shock-heated bubbles within PNe. CHANPLANS began with a combined Cycle 12 and archive Chandra survey of 35 PNe. CHANPLANS continued via a Chandra Cycle 14 Large Program which targeted all (24) remaining known compact (R {sub neb} ≲ 0.4 pc), young PNe that lie within ∼1.5 kpc. Results from these Cycle 14 observations include first-time X-ray detections of hot bubbles within NGC 1501, 3918, 6153, and 6369, and point sources in HbDs 1, NGC 6337, and Sp 1. The addition of the Cycle 14 results brings the overall CHANPLANS diffuse X-ray detection rate to ∼27% and the point source detection rate to ∼36%. It has become clearer that diffuse X-ray emission is associated with young (≲ 5 × 10{sup 3} yr), and likewise compact (R {sub neb} ≲ 0.15 pc), PNe with closed structures and high central electron densities (n{sub e} ≳ 1000 cm{sup –3}), and is rarely associated with PNe that show H{sub 2} emission and/or pronounced butterfly structures. Hb 5 is one such exception of a PN with a butterfly structure that hosts diffuse X-ray emission. Additionally, two of the five new diffuse X-ray detections (NGC 1501 and NGC 6369) host [WR]-type central stars, supporting the hypothesis that PNe with central stars of [WR]-type are likely to display diffuse X-ray emission.

  8. 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.

  9. Luminous Binary Supersoft X-Ray Sources

    NASA Technical Reports Server (NTRS)

    Oliversen, Ronald J. (Technical Monitor); DiStefano, Roseanne

    2005-01-01

    One of the key accomplishments of the two preceding years was our development of an algorithm to select SSSs in external galaxies which have been observed by Chandra or XMM-Newton. By applying this algorithm to data from a number of galaxies, we discovered an extension of the class of SSSs to sources that are somewhat harder (100 - 300 eV, instead of tens of eV), but which are nevertheless much softer than canonical X-ray sources. We call these new sources quasisoft sources (QSSs). During this past year, we have built on and extended this work. We have (1) continued to identify SSSs and QSSs in external galaxies, (2) worked on models for the sources and find that black hole models seem promising for a subset of them, and (3) have studied individual systems, especially M101-ULX1. This special system has been observed as an SSS in its high &ate, with a luminosity in excess of 10(exp 41) erg/s. It has also been observed as a QSS when it is less luminous, and as a hard source in its low state. It is one of the best candidates to be an accreting intermediate-mass black hole. We have several papers in preparation. Below we list papers which are complete, including only new work and papers whose status has changed (e.g., been accepted for publication) since our last report. In addition, our work on QSSs has received some publicity. It was the subject of a Chandra press release and was picked up by several media outlets.

  10. 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

  11. X-ray spectral and optical properties of an ultraluminous X-ray source in NGC 4258 (M106)

    NASA Astrophysics Data System (ADS)

    Avdan, Hasan; Balman, Solen; Akyuz, Aysun; Avdan, Senay; Aksaker, Nazim; Akkaya Oralhan, İnci

    2016-07-01

    We report the X-ray and optical properties of an ultraluminous X-ray source (ULX) in the nearby galaxy NGC 4258 (M106). The XMM-Newton and Chandra archival observations were used to examine the X-ray spectral properties of the source. Throughout the X-ray observations, we discuss that the source appears to exhibit possible spectral changes by considering the hardness ratios and the spectral model parameters. The luminosity of the source varies a factor of two during the observations and has a peak value of ˜2x10^{39} erg s^{-1}. In the optical band, the source seems to belong to a star cluster. The archival HST images were used to search the optical counterpart of the ULX and three possible candidates were found within the 1σ error radius of 0.3". Also the mass for the compact object is estimated in the range of 10-15 M _{sun} which indicates a stellar-mass black hole.

  12. Nonlinear X-Ray and Auger Spectroscopy at X-Ray Free-Electron Laser Sources

    NASA Astrophysics Data System (ADS)

    Rohringer, Nina

    2015-05-01

    X-ray free-electron lasers (XFELs) open the pathway to transfer non-linear spectroscopic techniques to the x-ray domain. A promising all x-ray pump probe technique is based on coherent stimulated electronic x-ray Raman scattering, which was recently demonstrated in atomic neon. By tuning the XFEL pulse to core-excited resonances, a few seed photons in the spectral tail of the XFEL pulse drive an avalanche of resonant inelastic x-ray scattering events, resulting in exponential amplification of the scattering signal by of 6-7 orders of magnitude. Analysis of the line profile of the emitted radiation permits to demonstrate the cross over from amplified spontaneous emission to coherent stimulated resonance scattering. In combination with statistical covariance mapping, a high-resolution spectrum of the resonant inelastic scattering process can be obtained, opening the path to coherent stimulated x-ray Raman spectroscopy. An extension of these ideas to molecules and a realistic feasibility study of stimulated electronic x-ray Raman scattering in CO will be presented. Challenges to realizing stimulated electronic x-ray Raman scattering at present-day XFEL sources will be discussed, corroborated by results of a recent experiment at the LCLS XFEL. Due to the small gain cross section in molecular targets, other nonlinear spectroscopic techniques such as nonlinear Auger spectroscopy could become a powerful alternative. Theory predictions of a novel pump probe technique based on resonant nonlinear Auger spectroscopic will be discussed and the method will be compared to stimulated x-ray Raman spectroscopy.

  13. Determination of the mass of globular cluster X-ray sources

    NASA Technical Reports Server (NTRS)

    Grindlay, J. E.; Hertz, P.; Steiner, J. E.; Murray, S. S.; Lightman, A. P.

    1984-01-01

    The precise positions of the luminous X-ray sources in eight globular clusters have been measured with the Einstein X-Ray Observatory. When combined with similarly precise measurements of the dynamical centers and core radii of the globular clusters, the distribution of the X-ray source mass is determined to be in the range 0.9-1.9 solar mass. The X-ray source positions and the detailed optical studies indicate that (1) the sources are probably all of similar mass, (2) the gravitational potentials in these high-central density clusters are relatively smooth and isothermal, and (3) the X-ray sources are compact binaries and are probably formed by tidal capture.

  14. Compact integrated X-ray intensity and beam position monitor based on rare gas scintillation

    SciTech Connect

    Revesz, Peter; Ruff, Jacob; Dale, Darren; Krawczyk, Thomas

    2013-05-15

    We have created and tested a compact integrated X-ray beam intensity and position monitor using Ar-gas scintillation. The light generated inside the device's cavity is detected by diametrically opposed PIN diodes located above and below the beam. The intensity is derived from the sum of the top and bottom signals, while the beam position is calculated from the difference-over-sum of the two signals. The device was tested at Cornell High Energy Synchrotron Source with both 17 keV and 59 keV x-rays. For intensity monitoring, the Ar-scintillation monitor performance is comparable to standard ion chambers in terms of precision. As an X-ray beam position monitor the new device response is linear with vertical beam position over a 2 mm span with a precision of 2 {mu}m.

  15. 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.

  16. Infrared observations of galactic bulge X-ray sources

    NASA Technical Reports Server (NTRS)

    Hertz, P.; Grindlay, J. E.

    1984-01-01

    Nine unidentified galactic bulge X-ray sources, the recently identified X-ray burster MXB 1728-34, and two optically identified sources (Sco X-1 and MXB 1735-44) were observed with the NASA 3 m Infrared Telescope Facility. The data constrain both the presence of diffuse infrared sources near the X-ray positions and the flux of possible infrared counterparts. None of the nine unidentified sources lies within obscured globular clusters, although there is marginal evidence for diffuse infrared emission near 4U 1822-00 and 4U 1916-05. This implies that at most two additional luminous galactic bulge X-ray sources lie within undiscovered, obscured globular clusters. No infrared counterparts were detected for unidentified sources; the limits derived are consistent with all of the sources observed being similar to the low mass X-ray binary Sco X-1.

  17. 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.

  18. X-ray time and spectral variability as probes of ultraluminous x-ray sources

    NASA Astrophysics Data System (ADS)

    Pasham, Dheeraj Ranga Reddy

    A long-standing debate in the field of ultraluminous X-ray sources (ULXs: luminosities > 3x1039 ergs s-1) is whether these objects are powered by stellar-mass black holes (mass range of 3-25 solar masses) undergoing hyper-accretion/emission or if they host the long-sought after class of intermediate-mass black holes (mass range of a few 100-1000 solar masses) accreting material at sub-Eddington rates. We present X-ray time and energy spectral variability studies of ULXs in order to understand their physical environments and accurately weigh their compact objects. A sample of ULXs exhibit quasi-periodic oscillations (QPOs) with centroid frequencies in the range of 10-200 mHz. The nature of the power density spectra (PDS) of these sources is qualitatively similar to stellar-mass black holes when they exhibit the so-called type-C low-frequency QPOs (frequency range of 0.2-15 Hz). However, the crucial difference is that the characteristic frequencies within the PDS of ULXs, viz., the break frequencies and the centroid frequencies of the QPOs, are scaled down by a factor of approximately 10-100 compared to stellar-mass black holes. It has thus been argued that the ULX mHz QPOs are the type-C low-frequency QPO analogs of stellar-mass black holes and that the observed difference in the frequencies (a fewx0.01 Hz compared with a few Hz) is due to the presence of intermediate-mass black holes ( MULX = (QPOstellar-mass black hole }/QPOULX)xM stellar-mass black hole, where M and QPO are the mass and the QPO frequency, respectively) within these ULXs. We analyzed all the archival XMM-Newton X-ray data of ULXs NGC 5408 X-1 and M82 X-1 in order to test the hypothesis that the ULX mHz QPOs are the type-C analogs by searching for a correlation between the mHz QPO frequency and the energy spectral power-law index as type-C QPOs show such a dependence. From our multi-epoch timing and spectral analysis of ULXs NGC 5408 X-1 and M82 X-1, we found that the mHz QPOs of these sources vary

  19. Polarimeter for Low Energy X-ray Astrophysical Sources (PLEXAS)

    NASA Technical Reports Server (NTRS)

    Murray, Stephen S.; Pierce, David L. (Technical Monitor)

    2002-01-01

    The Polarimeter for Low Energy X-ray Astrophysical Sources (PLEXAS) is an astrophysics mission concept for measuring the polarization of X-ray sources at low energies below the C-K band (less than 277 eV). PLEXAS uses the concept of variations in the reflectivity of a multilayered X-ray telescope as a function of the orientation of an X-rays polarization vector with respect to the reflecting surface of the optic. By selecting an appropriate multilayer, and rotating the X-ray telescope while pointing to a source, there will be a modulation in the source intensity, as measured at the focus of the telescope, which is proportional to the degree of polarization in the source.

  20. Micropinch x-ray source and its applications

    NASA Astrophysics Data System (ADS)

    Gurey, Anatoliy E.; Semyonov, Oleg G.; Tikhomirov, Adolf A.

    2000-11-01

    An experimental model of an industrial micropinch x-ray source is described on the basis of a low inductance vacuum spark. It was designed and tested for applications in x-ray lithography, x-ray microscopy, surface processing (micro-relief leveling) and structural modification of thin dielectric layers. The error analysis of proximity method and test results confirmed the adequacy of its application to produce microchips for the microelectronic industry with spatial resolution of < 0.1 (mu) . The x-ray microscopy of human and rabbit blood and tissue cells was performed using the proximity shadow printing method with the sensitive polymer detectors or resists.

  1. Deep Chandra Observations of the Compact Starburst Galaxy Henize 2–10: X-Rays from the Massive Black Hole

    NASA Astrophysics Data System (ADS)

    Reines, Amy E.; Reynolds, Mark T.; Miller, Jon M.; Sivakoff, Gregory R.; Greene, Jenny E.; Hickox, Ryan C.; Johnson, Kelsey E.

    2016-10-01

    We present follow-up X-ray observations of the candidate massive black hole (BH) in the nucleus of the low-mass, compact starburst galaxy Henize 2–10. Using new high-resolution observations from the Chandra X-ray Observatory totaling 200 ks in duration, as well as archival Chandra observations from 2001, we demonstrate the presence of a previously unidentified X-ray point source that is spatially coincident with the known nuclear radio source in Henize 2–10 (i.e., the massive BH). We show that the hard X-ray emission previously identified in the 2001 observation is dominated by a source that is distinct from the nucleus, with the properties expected for a high-mass X-ray binary. The X-ray luminosity of the nuclear source suggests the massive BH is radiating significantly below its Eddington limit (∼10{}-6 {L}{Edd}), and the soft spectrum resembles other weakly accreting massive BHs including Sagittarius A*. Analysis of the X-ray light curve of the nucleus reveals the tentative detection of a ∼9 hr periodicity, although additional observations are required to confirm this result. Our study highlights the need for sensitive high-resolution X-ray observations to probe low-level accretion, which is the dominant mode of BH activity throughout the universe.

  2. 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.

  3. 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

  4. Attenuation of supersoft X-ray sources by circumstellar material

    NASA Astrophysics Data System (ADS)

    Nielsen, M. T. B.; Gilfanov, M.

    2015-11-01

    Recent studies have suggested the possibility of significantly obscuring supersoft X-ray sources in relatively modest amounts of local matter lost from the binaries themselves. If correct, then this would have explained the paucity of observed supersoft X-ray sources and would have significance for the search for single-degenerate Type Ia supernova progenitors. We point out that earlier studies of circumbinary obscuration ignored photoionizations of the gas by the emission from the supersoft X-ray source. We revisit the problem using a full, self-consistent calculation of the ionization state of the circumbinary material photoionized by the radiation of the central source. Our results show that the circumstellar mass-loss rates required for obscuration of supersoft X-ray sources is about an order of magnitude larger than those reported in earlier studies, for comparable model parameters. While this does not entirely rule out the possibility of circumstellar material obscuring supersoft X-ray sources, it makes it unlikely that this effect alone can account for the majority of the missing supersoft X-ray sources. We discuss the observational appearance of hypothetical obscured nuclear-burning white dwarfs and show that they have signatures making them distinct from photoionized nebulae around supersoft X-ray sources imbedded in the low-density interstellar medium.

  5. 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.

  6. Femtosecond x-ray pulse generation with a compact electron storage ring

    SciTech Connect

    Yamada, H. |

    1996-04-01

    A novel method for generating brilliant x-ray beams is proposed, in which inelastic collisions of circulating relativistic electrons and a thin wire target are used. The high brilliance of this new photon source is based on narrow angular divergence due to the kinematics of relativistic electrons, and repeated use of electron beams. The estimated brilliance of this source in a 50-MeV electron storage ring is comparable to that of a compact synchrotron light source. {copyright} {ital 1996 American Institute of Physics.}

  7. The Chandra Planetary Nebula Survey (ChanPlaNS). II. X-Ray Emission from Compact Planetary Nebulae

    NASA Astrophysics Data System (ADS)

    Freeman, M.; Montez, R., Jr.; Kastner, J. H.; Balick, B.; Frew, D. J.; Jones, D.; Miszalski, B.; Sahai, R.; Blackman, E.; Chu, Y.-H.; De Marco, O.; Frank, A.; Guerrero, M. A.; Lopez, J. A.; Zijlstra, A.; Bujarrabal, V.; Corradi, R. L. M.; Nordhaus, J.; Parker, Q. A.; Sandin, C.; Schönberner, D.; Soker, N.; Sokoloski, J. L.; Steffen, M.; Toalá, J. A.; Ueta, T.; Villaver, E.

    2014-10-01

    We present results from the most recent set of observations obtained as part of the Chandra X-ray observatory Planetary Nebula Survey (ChanPlaNS), the first comprehensive X-ray survey of planetary nebulae (PNe) in the solar neighborhood (i.e., within ~1.5 kpc of the Sun). The survey is designed to place constraints on the frequency of appearance and range of X-ray spectral characteristics of X-ray-emitting PN central stars and the evolutionary timescales of wind-shock-heated bubbles within PNe. ChanPlaNS began with a combined Cycle 12 and archive Chandra survey of 35 PNe. ChanPlaNS continued via a Chandra Cycle 14 Large Program which targeted all (24) remaining known compact (R neb <~ 0.4 pc), young PNe that lie within ~1.5 kpc. Results from these Cycle 14 observations include first-time X-ray detections of hot bubbles within NGC 1501, 3918, 6153, and 6369, and point sources in HbDs 1, NGC 6337, and Sp 1. The addition of the Cycle 14 results brings the overall ChanPlaNS diffuse X-ray detection rate to ~27% and the point source detection rate to ~36%. It has become clearer that diffuse X-ray emission is associated with young (lsim 5 × 103 yr), and likewise compact (R neb <~ 0.15 pc), PNe with closed structures and high central electron densities (ne >~ 1000 cm-3), and is rarely associated with PNe that show H2 emission and/or pronounced butterfly structures. Hb 5 is one such exception of a PN with a butterfly structure that hosts diffuse X-ray emission. Additionally, two of the five new diffuse X-ray detections (NGC 1501 and NGC 6369) host [WR]-type central stars, supporting the hypothesis that PNe with central stars of [WR]-type are likely to display diffuse X-ray emission.

  8. Modifications of the X-ray source and monitor at the X-ray Calibration Facility

    NASA Technical Reports Server (NTRS)

    Newbolt, W. Barlow

    1986-01-01

    In order to test the instruments aboard the Advanced X-ray Astrophysics Facility (AXAF) some modifications will need to be made in the X-ray Calibration Facility at Marshall. Several of these modifications involve the X-ray source and the monitor. The source was redesigned to increase the spectral purity of the beam and decrease its polarization by minimizing the number of bremsstrahlung photons in the beam. This was accomplished by utilizing an annular electron gun which allowed the beam to take off antiparallel to the direction at which electrons are incident on the anode. Two other features of the source are the conical anode which decreases the effective spot size and a rotatable anode and filter wheel which allow the operator to change targets without breaking vacuum. The monitor is an important part of the facility because it is used to determine the X-ray flux at the target. A commercially available solid-state detector, Si(Li), should be used along with appropriate proportional counters for monitoring. This detector will be particularly useful when energy or wavelength dispersive instruments are tested because of its good resolution.

  9. An extended superhot solar flare X-ray source

    NASA Technical Reports Server (NTRS)

    Hudson, H. S.; Ohki, K. I.; Tsuneta, S.

    1985-01-01

    A superhot hard X-ray source in a solar flare occulted by the solar limb was identified. Its hard X-ray image was found to show great horizontal extent but little vertical extent. An H alpha brightening at the same limb position about an hour later suggests a multi-component loop prominence system, so that it appears that a superhot source can evolve in the same manner as a normal solar soft X-ray source. The assignment of plausiable values to physical parameters in the source suggests (from the simplest form of classical thermal-conduction theory) that either new physics will be required to suppress conduction, or else that gradual energy release well after the impulsive phase of the flare must occur. In this respect too, the superhot source appears to resemble ordinary soft X-ray sources, except of course that its temperature is higher.

  10. An extended superhot solar flare X-ray source

    NASA Astrophysics Data System (ADS)

    Hudson, H. S.; Ohki, K. I.; Tsuneta, S.

    1985-08-01

    A superhot hard X-ray source in a solar flare occulted by the solar limb was identified. Its hard X-ray image was found to show great horizontal extent but little vertical extent. An H alpha brightening at the same limb position about an hour later suggests a multi-component loop prominence system, so that it appears that a superhot source can evolve in the same manner as a normal solar soft X-ray source. The assignment of plausiable values to physical parameters in the source suggests (from the simplest form of classical thermal-conduction theory) that either new physics will be required to suppress conduction, or else that gradual energy release well after the impulsive phase of the flare must occur. In this respect too, the superhot source appears to resemble ordinary soft X-ray sources, except of course that its temperature is higher.

  11. 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.

  12. Theory of magnetic cataclysmic binary X-ray sources

    NASA Technical Reports Server (NTRS)

    Lamb, Don Q.

    1988-01-01

    The theory of magnetic cataclysmic binary X-ray sources is reviewed. The physics of the accretion torque for disk and for stream accretion is described, and the magnetic field strengths of DQ Her stars inferred from their spin behavior and of AM Her stars from direct measurement are discussed. The implications of disk and stream accretion for the geometry of the emission region and for the X-ray pulse profiles are considered. The physicl properties of the X-ray emission region and the expected infrared, optical, soft X-ray, and hard X-ray spectra are described. The orientations of the magnetic moment in AM Her stars inferred from the circular and linear polarization of the optical light and the optical light curve are commented on.

  13. 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.

  14. Automated classification of Chandra X-ray sources

    NASA Astrophysics Data System (ADS)

    Brehm, Derek; Kargaltsev, O.; Rangelov, B.; Volkov, I.; Pavlov, G. G.

    2014-01-01

    With the advent of the latest generation X-ray telescopes there has been a major influx of data associated with the detection of hundreds of thousands X-ray sources. As one can rarely tell a source type from its X-ray properties alone, the full potential of the X-ray catalogs can only be unlocked by correlating multiwavelength (MW) properties via cross-identification with other surveys. However, one would spend an enormous amount of time classifying these objects by their physical nature if the classification was to be done on a source-by-source basis by humans. Therefore, we are using a supervised learning algorithm to classify sources detected by the Chandra X-ray Observatory. The classifications are based on a training dataset which currently includes about 7,000 X-ray sources of known nature (main sequence stars, Wolf-Rayet stars, young stars, active galactic nuclei, low mass X-ray binaries, high mass x-ray binaries, and neutron stars). For each source, the training dataset includes up to 24 multiwavelength properties. The efficiency and accuracy of the classification is verified by dividing the training dataset in two and performing cross-validation. The results are also inspected by plotting source properties in 2D slices of the parameter space. As an application of our automated procedure we classified unidentified sources in the supernova remnant (SNR) G352.7-0.1, in the field of HESS J1809-193, and in part of the Chandra Source Catalog 1.0. We present the results of the verification tests and the classification results. This research was partially supported by NASA/SAO grant AR3-14017X.

  15. 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.

  16. 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.

  17. 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.

  18. New Directions in X-Ray Light Sources

    ScienceCinema

    Falcone, Roger

    2016-07-12

    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.

  19. 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.

  20. NEAR-INFRARED COUNTERPARTS OF CHANDRA X-RAY SOURCES TOWARD THE GALACTIC CENTER

    SciTech Connect

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

    2010-10-01

    The Chandra X-ray Observatory has now discovered nearly 10,000 X-ray point sources in the 2{sup 0} x 0.{sup 0}8 region around the Galactic Center. The sources are likely to be a population of accreting binaries in the Galactic Center, but little else is known of their nature. We obtained JHK{sub s} imaging of the 17' x 17' region around Sgr A*, an area containing 4339 of these X-ray sources, with the ISPI camera on the Cerro Tololo Inter-American Observatory (CTIO) 4 m telescope. We cross-correlate the Chandra and ISPI catalogs to find potential IR counterparts to the X-ray sources. The extreme IR source crowding in the field means that it is not possible to establish the authenticity of the matches with astrometry and photometry alone. We find 2137 IR/X-ray astrometrically matched sources: statistically, we estimate that our catalog contains 289 {+-} 13 true matches to soft X-ray sources and 154 {+-} 39 matches to hard X-ray sources. However, the fraction of true counterparts to candidate counterparts for hard sources is just 11%, compared to 60% for soft sources, making hard source NIR matches particularly challenging for spectroscopic follow-up. We calculate a color-magnitude diagram (CMD) for the matches to hard X-ray sources, and find regions where significant numbers of the IR matches are real. We use their CMD positions to place limits on the absolute K{sub s} -band magnitudes of the potential NIR counterparts to hard X-ray sources. We find regions of the counterpart CMD with 9 {+-} 3 likely Wolf-Rayet/supergiant binaries (with four spectroscopically confirmed in the literature) as well as 44 {+-} 13 candidates that could consist of either main-sequence high mass X-ray binaries or red giants with an accreting compact companion. In order to aid spectroscopic follow-up, we sort the candidate counterpart catalog on the basis of IR and X-ray properties to determine which source characteristics increase the probability of a true match. We find a set of 98 IR

  1. Complete multiwavelength evolution of galactic black hole transients during outburst decay. II. Compact jets and X-ray variability properties

    SciTech Connect

    Dinçer, T.; Kalemci, E.; Tomsick, J. A.; Buxton, M. M.; Bailyn, C. D.

    2014-11-01

    We investigated the relation between compact jet emission and X-ray variability properties of all black hole transients with multiwavelength coverage during their outburst decays. We studied the evolution of all power spectral components (including low-frequency quasi-periodic oscillations; QPOs), and related this evolution to changes in jet properties tracked by radio and infrared observations. We grouped sources according to their tracks in the radio/X-ray luminosity relation and show that the standards show stronger broadband X-ray variability than outliers at a given X-ray luminosity when the compact jet turns on. This trend is consistent with the internal shock model and can be important for the understanding of the presence of tracks in the radio/X-ray luminosity relation. We also observed that the total and the QPO rms amplitudes increase together during the earlier part of the outburst decay, but after the compact jet turns, either the QPO disappears or its rms amplitude decreases significantly while the total rms amplitudes remain high. We discuss these results with a scenario including a variable corona and a non-variable disk with a mechanism for the QPO separate from the mechanism that creates broad components. Finally, we evaluated the timing predictions of the magnetically dominated accretion flow model that can explain the presence of tracks in the radio/X-ray luminosity relation.

  2. ULTRALUMINOUS X-RAY SOURCES IN ARP 147

    SciTech Connect

    Rappaport, S.; Steinhorn, B.; Levine, A.; Pooley, D. E-mail: aml@space.mit.ed

    2010-10-01

    The Chandra X-Ray Observatory was used to image the collisional ring galaxy Arp 147 for 42 ks. We detect nine X-ray sources with luminosities in the range of (1.4-7) x 10{sup 39} erg s{sup -1} (assuming that the sources emit isotropically) in or near the blue knots of star formation associated with the ring. A source with an X-ray luminosity of 1.4 x 10{sup 40} erg s{sup -1} is detected in the nuclear region of the intruder galaxy. X-ray sources associated with a foreground star and a background quasar are used to improve the registration of the X-ray image with respect to Hubble Space Telescope (HST) high-resolution optical images. The intruder galaxy, which apparently contained little gas before the collision, shows no X-ray sources other than the one in the nuclear bulge which may be a poorly fed supermassive black hole. These observations confirm the conventional wisdom that collisions of gas-rich galaxies trigger large rates of star formation which, in turn, generate substantial numbers of X-ray sources, some of which have luminosities above the Eddington limit for accreting stellar-mass black holes (i.e., ultraluminous X-ray sources, 'ULXs'). We also utilize archival Spitzer and Galex data to help constrain the current star formation rate in Arp 147 to {approx}7 M{sub sun} yr{sup -1}. All of these results, coupled with binary evolution models for ULXs, allow us to tentatively conclude that the most intense star formation may have ended some 15 Myr in the past.

  3. Phase-contrast x-ray imaging with a liquid-metal-jet-anode microfocus source

    SciTech Connect

    Tuohimaa, T.; Otendal, M.; Hertz, H. M.

    2007-08-13

    Phase-contrast methods increase contrast, detail, and selectivity in x-ray imaging. Present compact x-ray sources do not provide the necessary spatial coherence with sufficient power to allow the laboratory-scale high-resolution phase-contrast imaging with adequate exposure times. In this letter, the authors demonstrate phase-contrast imaging with few-micron detail employing a compact {approx}6.5 {mu}m spot liquid-metal-jet-anode high-brightness microfocus source. The 40 W source is operated at more than ten times higher electron-beam power density than present microfocus sources and is shown to provide sufficient spatial coherence as well as scalability to high power, thereby enabling the application of phase-contrast x-ray imaging with short exposure times in clinics and laboratories.

  4. 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

  5. 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.

  6. Simulations of a Johann/Johansson diffraction spectrometer for x-ray experiments at an electron beam ion source

    NASA Astrophysics Data System (ADS)

    Jabłoński, Ł.; Jagodziński, P.; Banaś, D.; Pajek, M.

    2013-09-01

    The ray tracing simulations of x-ray spectra for a compact six-crystal Johann/Johansson diffraction spectrometer covering a wide photon energy range (70 eV-15 keV), i.e. from the extended ultraviolet to the hard x-ray region, are discussed in the context of x-ray experiments at an electron beam ion source facility. In particular, the x-ray line profiles and energy resolution for different diffraction crystals and multilayers were studied, and the effects of extension of x-ray source size and misalignment were investigated. The simulations were also performed for x-ray emission from solid targets bombarded by electrons, which will be used for calibration of the x-ray spectrometer.

  7. High resolution, large field of view x-ray differential phase contrast imaging on a compact setup

    SciTech Connect

    Thuering, T.; Stampanoni, M.; Modregger, P.; Grund, T.; Kenntner, J.; David, C.

    2011-07-25

    X-ray grating interferometry is a well established technique to perform differential phase contrast imaging on conventional x-ray tubes. So far, the application of this technique in commercial micro computed tomography scanners has remained a major challenge due to the compact setup geometry. In this letter, we report on the design of a compact imaging setup using a microfocus source. Due to the extreme wave front curvature, the gratings are fabricated on a flexible substrate, enabling precise cylindrical shaping. A laboratory setup and a modified SCANCO {mu}CT100 scanner have been built, allowing high resolution and large field of view imaging.

  8. The BL LAC phenomenon: X-ray observations of transition objects and determination of the x-ray spectrum of a complete sample of flat-spectrum radio sources

    NASA Technical Reports Server (NTRS)

    Worrall, Diana M.

    1994-01-01

    This report summarizes the activities related to two ROSAT investigations: (1) x-ray properties of radio galaxies thought to contain BL Lac type nuclei; and (2) x-ray spectra of a complete sample of flat-spectrum radio sources. The following papers describing the research are provided as attachments: Multiple X-ray Emission Components in Low Power Radio Galaxies; New X-ray Results on Radio Galaxies; Analysis Techniques for a Multiwavelength Study of Radio Galaxies; Separation of X-ray Emission Components in Radio Galaxies; X-ray Emission in Powerful Radio Galaxies and Quasars; Extended and Compact X-ray Emission in Powerful Radio Galaxies; and X-ray Spectra of a Complete Sample of Extragalactic Core-dominated Radio Sources.

  9. A 9 keV electron-impact liquid-gallium-jet x-ray source

    SciTech Connect

    Otendal, M.; Tuohimaa, T.; Vogt, U.; Hertz, H. M.

    2008-01-15

    We demonstrate a high-brightness compact 9 keV electron-impact microfocus x-ray source based on a liquid-gallium-jet anode. A {approx}30 W, 50 kV electron gun is focused onto the {approx}20 m/s, 30 {mu}m diameter liquid-gallium-jet anode to produce an {approx}10 {mu}m full width at half maximum x-ray spot. The peak spectral brightness is >2x10{sup 10} photons/(s mm{sup 2} mrad{sup 2}x0.1% BW). Calculation and experiments show potential for increasing this brightness by approximately three orders of magnitude, making the source suitable for laboratory-scale x-ray crystallography and hard x-ray microscopy.

  10. A Compact X-Ray System for Macromolecular Crystallography

    NASA Technical Reports Server (NTRS)

    Gubarev, Mikhail; Ciszak, Ewa; Ponomarev, Igor; Gibson, Walter; Joy, Marshall

    2000-01-01

    We describe the design and performance of a high flux x-ray system for a macromolecular crystallography that combines a microfocus x-ray generator (40 micrometer full width at half maximum spot size at a power level of 46.5 W) and a collimating polycapillary optic. The Cu Ka lpha x-ray flux produced by this optimized system through a 500,um diam orifice is 7.0 times greater than the x-ray flux previously reported by Gubarev et al. [M. Gubarev et al., J. Appl. Crystallogr. 33, 882 (2000)]. The x-ray flux from the microfocus system is also 2.6 times higher than that produced by a rotating anode generator equipped with a graded multilayer monochromator (green optic, Osmic Inc. CMF24-48-Cu6) and 40% less than that produced by a rotating anode generator with the newest design of graded multilayer monochromator (blue optic, Osmic, Inc. CMF12-38-Cu6). Both rotating anode generators operate at a power level of 5000 W, dissipating more than 100 times the power of our microfocus x-ray system. Diffraction data collected from small test crystals are of high quality. For example, 42 540 reflections collected at ambient temperature from a lysozyme crystal yielded R(sub sym)=5.0% for data extending to 1.70 A, and 4.8% for the complete set of data to 1.85 A. The amplitudes of the observed reflections were used to calculate difference electron density maps that revealed positions of structurally important ions and water molecules in the crystal of lysozyme using the phases calculated from the protein model.

  11. A Compact X-Ray System for Macromolecular Crystallography. 5

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

    We describe the design and performance of a high flux x-ray system for macromolecular crystallography that combines a microfocus x-ray generator (40 gm FWHM spot size at a power level of 46.5Watts) and a 5.5 mm focal distance polycapillary optic. The Cu K(sub alpha) X-ray flux produced by this optimized system is 7.0 times above the X-ray flux previously reported. The X-ray flux from the microfocus system is also 3.2 times higher than that produced by the rotating anode generator equipped with a long focal distance graded multilayer monochromator (Green optic; CMF24-48-Cu6) and 30% less than that produced by the rotating anode generator with the newest design of graded multilayer monochromator (Blue optic; CMF12-38-Cu6). Both rotating anode generators operate at a power level of 5000 Watts, dissipating more than 100 times the power of our microfocus x-ray system. Diffraction data collected from small test crystals are of high quality. For example, 42,540 reflections collected at ambient temperature from a lysozyme crystal yielded R(sub sym) 5.0% for the data extending to 1.7A, and 4.8% for the complete set of data to 1.85A. The amplitudes of the reflections were used to calculate difference electron density maps that revealed positions of structurally important ions and water molecules in the crystal of lysozyme using the phases calculated from the protein model.

  12. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2013-04-01

    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.

  14. Assembling x-ray sources by carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Sessa, V.; Lucci, M.; Toschi, F.; Orlanducci, S.; Tamburri, E.; Terranova, M. L.; Ciorba, A.; Rossi, M.; Hampai, D.; Cappuccio, G.

    2007-05-01

    By the use of a chemical vapour deposition technique a series of metal wires (W, Ta, Steel ) with differently shaped tips have been coated by arrays of single wall carbon nanotubes (SWNT). The field emission properties of the SWNT deposits have been measured by a home made apparatus working in medium vacuum (10 -6- 10 -7 mbar) and the SWNT-coated wires have been used to fabricate tiny electron sources for X-ray tubes. To check the efficiency of the nanotube coated wires for X-ray generation has, a prototype X-ray tube has been designed and fabricated. The X-ray tube works at pressures about 10 -6 mbar. The target ( Al film) is disposed on a hole in the stainless steel sheath: this configuration makes unnecessary the usual Be window and moreover allows us to use low accelerating potentials (< 6 kV).

  15. Development of a Novel Tunable X-Ray Source for the RPI-LINAC

    SciTech Connect

    Y. Danon; R.C. Block

    2004-11-30

    This document summarizes the results of a three year effort to develop a parametric x-ray (PXR) source. The emphasis of this research was to demonstrate production of high yield monoenergetic x-rays. Production of PXR is accomplished by placing a crystal in a relativistic electron beam. The process was first demonstrated in 1985 in Russia. Numerous papers were written about the characteristics of PXR from both experimental and theoretical perspectives. The advantage of PXR over other monoenergetic x-ray sources is that it is produced at large angle relative to the electron beam and at high intensity. None of the previous work described in the literature capitalized on this effect to study what is required in order to generate an effective monoenergetic x-ray source that can be used for practical applications. The work summarized here describes the process done in order to optimize the PXR production process by selecting an appropriate crystal and the optimal conditions. The research focused on production of 18 keV x-rays which are suitable for mammography however the results are not limited to this application or energy range. We are the first group to demonstrate x-ray imaging using PXR. Such sources can improve current medical imaging modalities. More research is required in order to design a prototype of a compact source.

  16. High-resolution x-ray imaging of a globular cluster core: compact binaries in 47Tuc.

    PubMed

    Grindlay, J E; Heinke, C; Edmonds, P D; Murray, S S

    2001-06-22

    We have obtained high-resolution (approximately 1") deep x-ray images of the globular cluster 47Tucanae (NGC 104) with the Chandra X-ray Observatory to study the population of compact binaries in the high stellar density core. A 70-kilosecond exposure of the cluster reveals a centrally concentrated population of faint (Lx approximately 10(30-33) ergs per second) x-ray sources, with at least 108 located within the central 2' x 2.5' and greater, similar half with Lx approximately 10(30.5) ergs per second. All 15 millisecond pulsars (MSPs) recently located precisely by radio observations are identified, though 2 are unresolved by Chandra. The x-ray spectral and temporal characteristics, as well as initial optical identifications with the Hubble Space Telescope, suggest that greater, similar50 percent are MSPs, about 30 percent are accreting white dwarfs, about 15 percent are main-sequence binaries in flare outbursts, and only two to three are quiescent low-mass x-ray binaries containing neutron stars, the conventional progenitors of MSPs. An upper limit of about 470 times the mass of the sun is derived for the mass of an accreting central black hole in the cluster. These observations provide the first x-ray "color-magnitude" diagram for a globular cluster and census of its compact object and binary population. PMID:11358997

  17. A long-period, violently variable X-ray source in a young supernova remnant.

    PubMed

    De Luca, A; Caraveo, P A; Mereghetti, S; Tiengo, A; Bignami, G F

    2006-08-11

    Observations with the Newton X-ray Multimirror Mission satellite show a strong periodic modulation at 6.67 +/- 0.03 hours of the x-ray source at the center of the 2000-year-old supernova remnant RCW 103. No fast pulsations are visible. If genetically tied to the supernova remnant, the source could either be an x-ray binary, composed of a compact object and a low-mass star in an eccentric orbit, or an isolated neutron star. In the latter case, the combination of its age and period would indicate that it is a peculiar magnetar, dramatically slowed down, possibly by a supernova debris disc. Both scenarios require nonstandard assumptions about the formation and evolution of compact objects in supernova explosions.

  18. XMM-Newton reveals extreme winds in ultraluminous X-ray sources

    NASA Astrophysics Data System (ADS)

    Pinto, C.; Middleton, M.; Fabian, A.

    2016-06-01

    Ultraluminous X-ray sources are extragalactic, off-nucleus, point sources with X-ray luminosities above 10^{39} erg/s, thought to be powered by accretion onto compact objects. Viable solutions include accretion onto neutron stars with strong magnetic fields, stellar-mass black holes at or in excess of the Eddington limit or intermediate-mass black holes. The lack of sufficient energy resolution in previous analyses has prevented an unambiguous identification of any emission or absorption lines in the X-ray band, thereby precluding a detailed analysis of the accretion flow. In this talk, I will show the discovery of rest-frame emission and blueshifted (˜0.2c) absorption lines arising from highly ionized gas in the deep high-resolution XMM-Newton spectra of two ultraluminous X-ray sources. The blueshifted absorption lines occurs in a fast outflowing gas, whereas the emission lines originate in slow-moving gas around the source. The compact object is therefore surrounded by powerful winds with an outflow velocity of about 0.2c as predicted by models of hyper-accreting black holes. Further, deep, XMM-Newton observations will reveal powerful winds in many other ultraluminous X-ray sources and provide important hints to estimate the energetics of the wind, the geometry of the system, and the black hole masses.

  19. Optimized Volumetric Scanning for X-Ray Array Sources

    SciTech Connect

    Lehman, S K; Foudray, A M; Wang, A; Kallman, J S; Martz, H

    2009-09-29

    Non-destructive evaluation (NDE) is the science and technology of determining non-invasively the internal structure of manufactured parts, objects, and materials. NDE application areas include medicine, industrial manufacturing, military, homeland security, and airport luggage screening. X-ray measurement systems are most widely used because of their ability to image through a wide range of material densities (from human tissue in medical applications to the dense materials of weapon components). Traditional x-ray systems involve a single source and detector system that rotate and/or translate about the object under evaluation. At each angular location, the source projects x-rays through the object. The rays undergo attenuation proportional to the density of the object's constitutive material. The detector records a measure of the attenuation. Mathematical algorithms are used to invert the forward attenuated ray projection process to form images of the object. This is known as computed tomography (CT). In recent years, the single-source x-ray NDE systems have been generalized to arrays of x-ray sources. Array sources permit multiple views of the object with fewer rotations and translations of the source/detector system. The spatially diverse nature of x-ray array sources has the potential of reducing data collection time, reducing imaging artifacts, and increasing the resolution of the resultant images. Most of the existing CT algorithms were not derived from array source models with a spatially diverse set of viewing perspectives. Single-source x-ray CT data collection, processing, and imaging methods and algorithms are not applicable when the source location is expanded from one dimension (a rotating and/or translating point source) to two (a rotating and/or translating array). They must be reformulated. The goal of this project is to determine the applicability of x-ray array sources to problems of interest to LLNL and its customers. It is believed array source

  20. Compact scanning transmission x-ray microscope at the photon factory

    NASA Astrophysics Data System (ADS)

    Takeichi, Yasuo; Inami, Nobuhito; Suga, Hiroki; Takahashi, Yoshio; Ono, Kanta

    2016-01-01

    We report the design and performance of a compact scanning transmission X-ray microscope developed at the Photon Factory. Piezo-driven linear stages are used as coarse stages of the microscope to realize excellent compactness, mobility, and vibrational and thermal stability. An X-ray beam with an intensity of ˜107 photons/s was focused to a diameter of ˜40 nm at the sample. At the soft X-ray undulator beamline used with the microscope, a wide range of photon energies (250-1600 eV) is available. The microscope has been used to research energy materials and in environmental sciences.

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. On the optical identifications of five X-ray sources

    NASA Technical Reports Server (NTRS)

    Bradt, H. V.; Clark, G. W.; Dower, R.; Doxsey, R.; Hearn, D. R.; Jernigan, J. G.; Mayer, W.; Mcclintock, J.; Apparao, K. M. V.; Joss, P. C.

    1977-01-01

    The data from a recently completed survey of the galactic plane with the SAS-3 modulation collimators provide precise (20 to 60 arcsec) celestial positions of galactic X-ray sources. Preliminary positions of 60-arcsec precision are reported for five sources. One of these led to the identification of the star, Gamma Cas, as an X-ray source, and the others lend substantial confidence to previously proposed optical identifications: 3U 0352+30 = X Per, 3U 1145-61 = HEN 715, GX301-2 = WRA977, and GX304-1 = MMV star. These identifications seem to establish the existence of a previously suggested class of Be-star X-ray emitters.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

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

    SciTech Connect

    Puehlhofer, Gerd

    2009-05-11

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

  12. 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.

  13. 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...

  14. 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...

  15. 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...

  16. 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...

  17. 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...

  18. 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...

  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, 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...

  1. 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...

  2. 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...

  3. Resolved atomic lines reveal outflows in two ultraluminous X-ray sources.

    PubMed

    Pinto, Ciro; Middleton, Matthew J; Fabian, Andrew C

    2016-05-01

    Ultraluminous X-ray sources are extragalactic, off-nucleus, point sources in galaxies, and have X-ray luminosities in excess of 3 × 10(39) ergs per second. They are thought to be powered by accretion onto a compact object. Possible explanations include accretion onto neutron stars with strong magnetic fields, onto stellar-mass black holes (of up to 20 solar masses) at or in excess of the classical Eddington limit, or onto intermediate-mass black holes (10(3)-10(5) solar masses). The lack of sufficient energy resolution in previous analyses has prevented an unambiguous identification of any emission or absorption lines in the X-ray band, thereby precluding a detailed analysis of the accretion flow. Here we report the presence of X-ray emission lines arising from highly ionized iron, oxygen and neon with a cumulative significance in excess of five standard deviations, together with blueshifted (about 0.2 times light velocity) absorption lines of similar significance, in the high-resolution X-ray spectra of the ultraluminous X-ray sources NGC 1313 X-1 and NGC 5408 X-1. The blueshifted absorption lines must occur in a fast-outflowing gas, whereas the emission lines originate in slow-moving gas around the source. We conclude that the compact object in each source is surrounded by powerful winds with an outflow velocity of about 0.2 times that of light, as predicted by models of accreting supermassive black holes and hyper-accreting stellar-mass black holes. PMID:27120159

  4. Resolved atomic lines reveal outflows in two ultraluminous X-ray sources.

    PubMed

    Pinto, Ciro; Middleton, Matthew J; Fabian, Andrew C

    2016-05-01

    Ultraluminous X-ray sources are extragalactic, off-nucleus, point sources in galaxies, and have X-ray luminosities in excess of 3 × 10(39) ergs per second. They are thought to be powered by accretion onto a compact object. Possible explanations include accretion onto neutron stars with strong magnetic fields, onto stellar-mass black holes (of up to 20 solar masses) at or in excess of the classical Eddington limit, or onto intermediate-mass black holes (10(3)-10(5) solar masses). The lack of sufficient energy resolution in previous analyses has prevented an unambiguous identification of any emission or absorption lines in the X-ray band, thereby precluding a detailed analysis of the accretion flow. Here we report the presence of X-ray emission lines arising from highly ionized iron, oxygen and neon with a cumulative significance in excess of five standard deviations, together with blueshifted (about 0.2 times light velocity) absorption lines of similar significance, in the high-resolution X-ray spectra of the ultraluminous X-ray sources NGC 1313 X-1 and NGC 5408 X-1. The blueshifted absorption lines must occur in a fast-outflowing gas, whereas the emission lines originate in slow-moving gas around the source. We conclude that the compact object in each source is surrounded by powerful winds with an outflow velocity of about 0.2 times that of light, as predicted by models of accreting supermassive black holes and hyper-accreting stellar-mass black holes.

  5. Resolved atomic lines reveal outflows in two ultraluminous X-ray sources

    NASA Astrophysics Data System (ADS)

    Pinto, Ciro; Middleton, Matthew J.; Fabian, Andrew C.

    2016-05-01

    Ultraluminous X-ray sources are extragalactic, off-nucleus, point sources in galaxies, and have X-ray luminosities in excess of 3 × 1039 ergs per second. They are thought to be powered by accretion onto a compact object. Possible explanations include accretion onto neutron stars with strong magnetic fields, onto stellar-mass black holes (of up to 20 solar masses) at or in excess of the classical Eddington limit, or onto intermediate-mass black holes (103-105 solar masses). The lack of sufficient energy resolution in previous analyses has prevented an unambiguous identification of any emission or absorption lines in the X-ray band, thereby precluding a detailed analysis of the accretion flow. Here we report the presence of X-ray emission lines arising from highly ionized iron, oxygen and neon with a cumulative significance in excess of five standard deviations, together with blueshifted (about 0.2 times light velocity) absorption lines of similar significance, in the high-resolution X-ray spectra of the ultraluminous X-ray sources NGC 1313 X-1 and NGC 5408 X-1. The blueshifted absorption lines must occur in a fast-outflowing gas, whereas the emission lines originate in slow-moving gas around the source. We conclude that the compact object in each source is surrounded by powerful winds with an outflow velocity of about 0.2 times that of light, as predicted by models of accreting supermassive black holes and hyper-accreting stellar-mass black holes.

  6. Analysis of Off-Nuclear X-Ray Sources in Galaxy NGC 4945

    SciTech Connect

    Harrison, Sarah M.; /MIT /SLAC

    2006-09-11

    Recently, X-ray astronomy has been used to investigate objects such as galaxies, clusters of galaxies, Active Galactic Nuclei (AGN), quasars, starburst superbubbles of hot gas, X-ray binary systems, stars, supernova remnants, and interstellar and intergalactic material. By studying the x-ray emission patterns of these objects, we can gain a greater understanding of their structure and evolution. We analyze X-ray emission from the galaxy NGC 4945 using data taken by the Chandra X-ray Observatory. The Chandra Interactive Analysis of Observations (CIAO) software package was used to extract and fit energy spectra and to extract light curves for the brightest off-nuclear sources in two different observations of NGC 4945 (January, 2000 and May, 2004). A majority of sources were closely fit by both absorbed power law and absorbed bremsstrahlung models, with a significantly poorer {chi}{sup 2}/dof for the absorbed blackbody model, and most sources had little variability. This indicates that the sources are accreting binary systems with either a neutron star or black hole as the compact object. The calculated luminosities were about 10{sup 38} erg/s, which implies that the mass of the accreting object is close to 10 solar masses and must be a black hole.

  7. Chandra ACIS Survey of X-Ray Point Sources in Nearby Galaxies. II. X-Ray Luminosity Functions and Ultraluminous X-Ray Sources

    NASA Astrophysics Data System (ADS)

    Wang, Song; Qiu, Yanli; Liu, Jifeng; Bregman, Joel N.

    2016-09-01

    Based on the recently completed Chandra/ACIS survey of X-ray point sources in nearby galaxies, we study the X-ray luminosity functions (XLFs) for X-ray point sources in different types of galaxies and the statistical properties of ultraluminous X-ray sources (ULXs). Uniform procedures are developed to compute the detection threshold, to estimate the foreground/background contamination, and to calculate the XLFs for individual galaxies and groups of galaxies, resulting in an XLF library of 343 galaxies of different types. With the large number of surveyed galaxies, we have studied the XLFs and ULX properties across different host galaxy types, and confirm with good statistics that the XLF slope flattens from lenticular (α ˜ 1.50 ± 0.07) to elliptical (˜1.21 ± 0.02), to spirals (˜0.80 ± 0.02), to peculiars (˜0.55 ± 0.30), and to irregulars (˜0.26 ± 0.10). The XLF break dividing the neutron star and black hole binaries is also confirmed, albeit at quite different break luminosities for different types of galaxies. A radial dependency is found for ellipticals, with a flatter XLF slope for sources located between D 25 and 2D 25, suggesting the XLF slopes in the outer region of early-type galaxies are dominated by low-mass X-ray binaries in globular clusters. This study shows that the ULX rate in early-type galaxies is 0.24 ± 0.05 ULXs per surveyed galaxy, on a 5σ confidence level. The XLF for ULXs in late-type galaxies extends smoothly until it drops abruptly around 4 × 1040 erg s-1, and this break may suggest a mild boundary between the stellar black hole population possibly including 30 M ⊙ black holes with super-Eddington radiation and intermediate mass black holes.

  8. Galactic X-rays: Variable Sources in Hydromagnetic Waves.

    PubMed

    Lelevier, R E; Libby, L M

    1968-06-28

    Galactic sources of x-rays fluctuating in intensity are explained as being small regions, of enhanced gas density and temperature, emitting thermal Coulomb bremsstrahlung of kiloelectron-volt energies. Hydromagnetic wave motions, of the magnetic fields in the galactic spiral arms, produce the enhanced regions by compressing the clouds of ionized gas to which they are tied by their high electrical conductivity. From the observed periods of fluctuation of a few months, together with the hydromagnetic velocity, it is estimated that the average size of sources does not exceed 10(16) centimeters. By using the formula for Coulomb bremsstrahlung and requiring that the sources shall produce the observed x-ray fluxes, one finds a second estimate of size of sources in agreement at about 1016 centimeters. Such regions are too small to be observable radio sources with current radio telescopes.

  9. High-energy X-ray spectra of five sources.

    NASA Technical Reports Server (NTRS)

    Ricker, G. R.; Mcclintock, J. E.; Gerassimenko, M.; Lewin , W. H. G.

    1973-01-01

    On October 15-16, 1970, we carried out balloon X-ray observations from Australia at energies above 15 keV. We present the high-energy X-ray spectra of three sources discovered by us, GX 301-2, GX 304-1, and GX 1 + 4. The data suggest that these high-energy sources correspond to the sources 2U 1223-62, 2U 1258-61, and 2U 1728-24 respectively. We also present the spectra for two additional sources, GX 5-1 (2U 1757-25) and GX 3 + 1 (2U 1744-26). The average intensity of the highly variable source GX 301-2 was observed to be as great as Tau X-1 in the energy range 15-50 keV.

  10. 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

  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. 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.

  13. AGN content of X-ray, IR and radio sources

    NASA Astrophysics Data System (ADS)

    Mickaelian, A. M.; Paronyan, G. M.; Abrahamyan, H. V.; Gyulzadyan, M. V.; Mikayelyan, G. A.

    2016-09-01

    We have carried out a number of surveys and identification works related to X-ray, IR and radio sources and searched for extragalactic ones. Among them, most interesting are Active Galactic Nuclei (AGN) and Starburst (SB) Galaxies. Some 4500 AGN have been revealed from ROSAT BSC and FSC sources, and many more are hidden ones; those showing evidence of activity but with no emission lines in optical wavelengths. We estimated AGN content of X-ray sources as 52.9%. IR sources contain thousands of SBs, and most important are those having signs of interaction and/or merging. We have carried out optical identifications of IRAS point sources, and 1278 IR galaxies have been revealed, including LIRGs and ULIRGs. We have also combined IRAS PSC and FSC catalogs and compiled its extragalactic sample, which allowed to estimate AGN content among IR sources as 23.7%. Extragalactic radio sources contain bright galaxies, AGN and SBs. We have studied the border between AGN and normal galaxies by radio/optical flux ratios to establish which objects may be attributed to AGN based on radio properties. Interestingly, absolute majority of objects associated with both X-ray and radio sources are AGN.

  14. Automatic Classification of Time-variable X-Ray Sources

    NASA Astrophysics Data System (ADS)

    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.

  15. High power bremsstrahlung X-ray source for radiation processing

    NASA Astrophysics Data System (ADS)

    Yotsumoto, K.; Sunaga, H.; Tanaka, S.; Kanazawa, T.; Agematsu, T.; Tanaka, R.; Yoshida, K.; Taniguchi, S.; Sakamoto, I.; Tamura, N.

    The high power X-ray irradiation facility designed for the sterilization of medical appliances is described. The X-ray source consists of the 5 MeV, 300 kW Cockcroft Walton type of electron accelerator and the water cooled tantalum target. Conditions necessary for designing the X-ray target are conversion efficiency from electron beam to X-ray, thermal conductivity, readiness for machining and cost of the material. The conversion efficiency was determined through the Monte Carlo type calculation and obtained as 10.8 % for 3.667 g/cm 2 thickness (1 csda range) of tantalum target. In order to obtain the data on the source design, experiments have been carried out at the JAERI TAKASAKI 2 MeV, 60 kW Cockcroft-Walton type of electron accelerator equipped with a tantalum target. The size of package and the speed of conveyor was determined through the calculation of the absorbed dose distribution in the irradiated medium and the utilization efficiency.

  16. Compton-backscattering x-ray source for coronary angiography

    SciTech Connect

    Blumberg, L.N.

    1992-01-01

    An X-ray source utilizing Compton-backscattered (CB) photons in a 75-MeV electron storage ring containing an infrared FEL is proposed for producing 33.17-keV X-rays (Iodine K-edge) for coronary angiography. The X-ray intensity into a 4-mrad cone is computed as 7.21 [times] 10[sup 14]/sec for a 500-mA electron beam colliding with 0.2-J/bunch, 3.22-[mu]m photons from an in-ring IR-FEL at the 353.21-MHz rate of a SLAC-PEP 500-kW RF system. The resultant average flux at the patient is 6.4 [times] 10[sup 7] photons/pixel/4-msec aver a 12-cm diameter circle at 3-m from the interaction point for the 0.5 [times]0.5-mm[sup 2] pixel size of the present Si(Li) array of the BNL-SMERF Angiography Facility. This flux is 2.1 times larger than obtains at SMERF at a comparable source-to-patient distance and over an area sufficient to encompass the entire coronary region. However, the X-Ray energy spread due to kinematics alone is 2.63-keV, a factor of 35 larger then SMERF, and presents the major difficulty for the digital subtraction angiography method (DSA) envisioned.

  17. Compton-backscattering x-ray source for coronary angiography

    SciTech Connect

    Blumberg, L.N.

    1992-12-01

    An X-ray source utilizing Compton-backscattered (CB) photons in a 75-MeV electron storage ring containing an infrared FEL is proposed for producing 33.17-keV X-rays (Iodine K-edge) for coronary angiography. The X-ray intensity into a 4-mrad cone is computed as 7.21 {times} 10{sup 14}/sec for a 500-mA electron beam colliding with 0.2-J/bunch, 3.22-{mu}m photons from an in-ring IR-FEL at the 353.21-MHz rate of a SLAC-PEP 500-kW RF system. The resultant average flux at the patient is 6.4 {times} 10{sup 7} photons/pixel/4-msec aver a 12-cm diameter circle at 3-m from the interaction point for the 0.5 {times}0.5-mm{sup 2} pixel size of the present Si(Li) array of the BNL-SMERF Angiography Facility. This flux is 2.1 times larger than obtains at SMERF at a comparable source-to-patient distance and over an area sufficient to encompass the entire coronary region. However, the X-Ray energy spread due to kinematics alone is 2.63-keV, a factor of 35 larger then SMERF, and presents the major difficulty for the digital subtraction angiography method (DSA) envisioned.

  18. Laboratory soft x-ray source with foil target

    NASA Astrophysics Data System (ADS)

    Stephan, Karl-Heinz; Braeuninger, Heinrich W.

    1993-02-01

    We have developed a comparatively small soft x-ray source for application in our test facilities, which are used at present to support the developments of the astrophysical space projects XMM and AXAF. The instrument comprises a commercially available color television tube for generation of the electron beam, which is focused on exchangeable metal films serving as targets. The x rays are taken off after having transversed the foil target and have a sufficient spectral purity with regard to the experimental requirements. The maximum electric operating parameters correspond to an emission current of 100 (mu) A generated by a filament heating power of 6.6 watt at an accelerating voltage of 25 kV. The technical advantages of the instrument are lightweight construction, no water cooling, small size electric supply, cost efficient manufacturing, small sized focus, and quick access to the desired characteristic spectral line by exchange of a complete tube. We describe the measurements on the local x-ray intensity profile of the focus, the spectral features of the beam, and present the resulting performance data. A special development could be used as calibration sources in x-ray telescopes.

  19. Compact high current generator for x-ray radiography

    NASA Astrophysics Data System (ADS)

    Kharlov, A. V.; Kovalchuk, B. M.; Zorin, V. B.

    2006-12-01

    We report here a design of the portable high current generator, which can be used for a row of experiments and applications, including, but not limited to, X pinch, plasma focus, vacuum spark, etc. The X generator consists of the capacitor bank, multigap spark switch, load chamber, and built-in high voltage triggering generator. The capacitor bank consists of 12 General Atomics 35404 type capacitors (20nF, 25nH, 0.2Ω, 100kV). It stores ˜0.8kJ at 80kV charging voltage. Each three capacitors are commuted to a load by the multigap spark switch, which is able to commute by eight parallel channels. Switches operate in ambient air at atmospheric pressure. At 76kV charging voltage the generator provides ˜260kA with 120ns rise time and 5nH inductive load and ˜220kA with 145ns rise time and 10nH. Delay of output pulse relative to high voltage triggering pulse is ˜65ns with 5ns jitter. The dimensions of the generator are 1240×1240×225mm3 and the weight is ˜250kg, and only one high voltage power supply is required as additional equipment for the generator. The generator with a pumping system is placed on area about 0.5m2. Operation and handling are very simple, because no oil nor purified gases are required for the generator. The X generator has been successfully employed for experiments on the Ni X pinch load. X-ray pulse duration (full width at half maximum above 1keV) was about 5ns. Radiation yield Wr⩾500mJ was observed in the 1.2-1.5KeV range and Wr⩾20mJ in the 3-5keV energy range, which is comparable to results, obtained on the nanosecond accelerators. Clearly resolved images of 6μm wire indicate micron level size of hot spot. These results demonstrate possibility of this generator for application for x-ray backlighting.

  20. Compact high current generator for x-ray radiography

    SciTech Connect

    Kharlov, A. V.; Kovalchuk, B. M.; Zorin, V. B.

    2006-12-15

    We report here a design of the portable high current generator, which can be used for a row of experiments and applications, including, but not limited to, X pinch, plasma focus, vacuum spark, etc. The X generator consists of the capacitor bank, multigap spark switch, load chamber, and built-in high voltage triggering generator. The capacitor bank consists of 12 General Atomics 35404 type capacitors (20 nF, 25 nH, 0.2 {omega}, 100 kV). It stores {approx}0.8 kJ at 80 kV charging voltage. Each three capacitors are commuted to a load by the multigap spark switch, which is able to commute by eight parallel channels. Switches operate in ambient air at atmospheric pressure. At 76 kV charging voltage the generator provides {approx}260 kA with 120 ns rise time and 5 nH inductive load and {approx}220 kA with 145 ns rise time and 10 nH. Delay of output pulse relative to high voltage triggering pulse is {approx}65 ns with 5 ns jitter. The dimensions of the generator are 1240x1240x225 mm{sup 3} and the weight is {approx}250 kg, and only one high voltage power supply is required as additional equipment for the generator. The generator with a pumping system is placed on area about 0.5 m{sup 2}. Operation and handling are very simple, because no oil nor purified gases are required for the generator. The X generator has been successfully employed for experiments on the Ni X pinch load. X-ray pulse duration (full width at half maximum above 1 keV) was about 5 ns. Radiation yield W{sub r}{>=}500 mJ was observed in the 1.2-1.5 KeV range and W{sub r}{>=}20 mJ in the 3-5 keV energy range, which is comparable to results, obtained on the nanosecond accelerators. Clearly resolved images of 6 {mu}m wire indicate micron level size of hot spot. These results demonstrate possibility of this generator for application for x-ray backlighting.

  1. Planar Wire-Array Z-Pinch Implosion Dynamics and X-Ray Scaling at Multiple-MA Drive Currents for a Compact Multisource Hohlraum Configuration

    SciTech Connect

    Jones, B.; Ampleford, D. J.; Vesey, R. A.; Cuneo, M. E.; Coverdale, C. A.; Waisman, E. M.; Jones, M. C.; Fowler, W. E.; Stygar, W. A.; Serrano, J. D.; Vigil, M. P.; Esaulov, A. A.; Kantsyrev, V. L.; Safronova, A. S.; Williamson, K. M.; Chuvatin, A. S.; Rudakov, L. I.

    2010-03-26

    An indirect drive configuration is proposed wherein multiple compact Z-pinch x-ray sources surround a secondary hohlraum. Planar compact wire arrays allow reduced primary hohlraum surface area compared to cylindrical loads. Implosions of planar arrays are studied at up to 15 TW x-ray power on Saturn with radiated yields exceeding the calculated kinetic energy, suggesting other heating paths. X-ray power and yield scaling studied from 1-6 MA motivates viewfactor modeling of four 6-MA planar arrays producing 90 eV radiation temperature in a secondary hohlraum.

  2. Design and performance of a compact scanning transmission X-ray microscope at the Photon Factory.

    PubMed

    Takeichi, Y; Inami, N; Suga, H; Miyamoto, C; Ueno, T; Mase, K; Takahashi, Y; Ono, K

    2016-01-01

    We present a new compact instrument designed for scanning transmission X-ray microscopy. It has piezo-driven linear stages, making it small and light. Optical components from the virtual source point to the detector are located on a single optical table, resulting in a portable instrument that can be operated at a general-purpose spectroscopy beamline without requiring any major reconstruction. Careful consideration has been given to solving the vibration problem common to high-resolution microscopy, so as not to affect the spatial resolution determined by the Fresnel zone plate. Results on bacteriogenic iron oxides, single particle aerosols, and rare-earth permanent magnets are presented as examples of its performance under diverse applications. PMID:26827325

  3. Design and performance of a compact scanning transmission X-ray microscope at the Photon Factory.

    PubMed

    Takeichi, Y; Inami, N; Suga, H; Miyamoto, C; Ueno, T; Mase, K; Takahashi, Y; Ono, K

    2016-01-01

    We present a new compact instrument designed for scanning transmission X-ray microscopy. It has piezo-driven linear stages, making it small and light. Optical components from the virtual source point to the detector are located on a single optical table, resulting in a portable instrument that can be operated at a general-purpose spectroscopy beamline without requiring any major reconstruction. Careful consideration has been given to solving the vibration problem common to high-resolution microscopy, so as not to affect the spatial resolution determined by the Fresnel zone plate. Results on bacteriogenic iron oxides, single particle aerosols, and rare-earth permanent magnets are presented as examples of its performance under diverse applications.

  4. X-Ray Properties of the Youngest Radio Sources and Their Environments

    NASA Astrophysics Data System (ADS)

    Siemiginowska, Aneta; Sobolewska, Małgosia; Migliori, Giulia; Guainazzi, Matteo; Hardcastle, Martin; Ostorero, Luisa; Stawarz, Łukasz

    2016-05-01

    We present the first results from our X-ray study of young radio sources classified as compact symmetric objects (CSOs). Using the Chandra X-ray Observatory we observed six CSOs for the first time in X-rays, and re-observed four CSOs already observed with XMM-Newton or BeppoSAX. We also included six other CSOs with archival data to built a pilot study of a sample of the 16 CSO sources observed in X-rays to date. All the sources are nearby, z\\lt 1, and the age of their radio structures (\\lt 3000 yr) has been derived from the expansion velocity of their hot spots. Our results show the heterogeneous nature of the CSOs’ X-ray emission, indicating a complex environment associated with young radio sources. The sample covers a range in X-ray luminosity, {L}2{--10{keV}}˜ {10}41–1045 erg s‑1, and intrinsic absorbing column density of {N}{{H}}≃ {10}21–1022 cm‑2. In particular, we detected extended X-ray emission in 1718‑649 a hard photon index of {{Γ }}≃ 1 in 2021+614 and 1511+0518 consistent with either a Compton-thick absorber or non-thermal emission from compact radio lobes, and in 0710+439 an ionized iron emission line at {E}{rest}=(6.62+/- 0.04) keV and EW ˜ 0.15–1.4 keV, and a decrease by an order of magnitude in the 2–10 keV flux since the 2008 XMM-Newton observation in 1607+26. We conclude that our pilot study of CSOs provides a variety of exceptional diagnostics and highlights the importance of deep X-ray observations of large samples of young sources. This is necessary in order to constrain theoretical models for the earliest stage of radio source evolution and to study the interactions of young radio sources with the interstellar environment of their host galaxies.

  5. 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.

  6. Quasi-monochromatic hard X-ray source via laser Compton scattering and its application

    NASA Astrophysics Data System (ADS)

    Kuroda, R.; Toyokawa, H.; Yasumoto, M.; Ikeura-Sekiguchi, H.; Koike, M.; Yamada, K.; Yanagida, T.; Nakajyo, T.; Sakai, F.; Mori, K.

    2011-05-01

    We have developed a quasi-monochromatic hard X-ray source via laser Compton scattering (LCS) based on an S-band compact electron linac at AIST. The number of total photons and the maximum X-ray energy was 107 photons/sec and about 40 keV, respectively, in 15-degree crossing angle between a 42 MeV electron beam and a 800 nm Ti:Sa laser. The biological observation of the human bone with fractures has been successfully demonstrated using the LCS X-ray of 26.4 keV with the in-line phase contrast scheme. Good contrast enhancement is clearly observed between the absorption and the phase contrast images.

  7. Broadband X-ray Spectroscopy of the ADC Source 4U 1822-37 with Suzaku

    NASA Technical Reports Server (NTRS)

    Cottam, J.; White, N.

    2006-01-01

    We will present the broadband spectra of the low mass x-ray binary 4U 1822-37, recently observed with Suzaku. 4U 1822-37 is the canonical accretion disk corona (ADC) source where the compact object is obscured by an extended corona that intercepts and scatters the central continuum emission, some of which is then reprocessed in the outer regions of the accretion disk. 4U 1822-37 therefore serves as an important link between x-ray binaries and AGN. The broadband x-ray spectra from the Suzaku XIS and HXD provide a unique opportunity to probe the physical conditions in the corona and the accretion disk for this important accretion geometry.

  8. 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.

  9. 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.

  10. A Compact X-Band Linac for an X-Ray FEL

    SciTech Connect

    Adolphsen, Chris; Huang, Zhirong; Bane, Karl L.F.; Li, Zenghai; Zhou, Feng; Wang, Faya; Nantista, Christopher D.; /SLAC

    2011-09-12

    With the growing demand for FEL light sources, cost issues are being reevaluated. To make the machines more compact, higher frequency room temperature linacs are being considered, specifically ones using C-band (5.7 GHz) rf technology, for which 40 MV/m gradients are achievable. In this paper, we show that an X-band (11.4 GHz) linac using the technology developed for NLC/GLC can provide an even lower cost solution. In particular, stable operation is possible at gradients of 100 MV/m for single bunch operation and 70 MV/m for multibunch operation. The concern, of course, is whether the stronger wakefields will lead to unacceptable emittance dilution. However, we show that the small emittances produced in a 250 MeV, low bunch charge, LCLS-like S-band injector and bunch compressor can be preserved in a multi-GeV X-band linac with reasonable alignment tolerances. The successful lasing and operation of the LCLS [1] has generated world-wide interest in X-ray FELs. The demand for access to such a light source by researchers eager to harness the capabilities of this new tool far exceeds the numbers that can be accommodated, spurring plans for additional facilities. Along with cost, spatial considerations become increasingly important for a hard X-ray machine driven by a multi-GeV linac. The consequent need for high acceleration gradient focuses attention on higher frequency normal conducting accelerator technology, rather than the superconducting technology of a soft X-ray facility like FLASH. C-band technology, such as used by Spring-8, is a popular option, capable of providing 40 MV/m. However, more than a decade of R&D toward an X-band linear collider, centered at SLAC and KEK, has demonstrated that this frequency option can extend the gradient reach to the 70-100 MV/m range. The following design and beam dynamics calculations show an X-band linac to be an attractive choice on which to base an X-ray FEL.

  11. kHz femtosecond laser-plasma hard X-ray and fast ion source

    NASA Astrophysics Data System (ADS)

    Thoss, A.; Korn, G.; Richardson, M. C.; Faubel, M.; Stiel, H.; Voigt, U.; Siders, C. W.; Elsaesser, T.

    2002-04-01

    We describe the first demonstration of a new stable, kHz femtosecond laser-plasma source of hard x-ray continuum and Kα emission using a thin liquid metallic jet target. kHz femtosecond x-ray sources will find many applications in time-resolved x-ray diffraction and microscopy studies. As high intensity lasers become more compact and operate at increasingly high repetition-rates, they require a target configuration that is both repeatable from shot-to-shot and is debris-free. We have solved this requirement with the use of a fine (10-30 μm diameter) liquid metal jet target that provides a pristine, unperturbed filament surface at rates >100 kHz. A number of liquid metal targets are considered. We will show hard x-ray spectra recorded from liquid Ga targets that show the generation of the 9.3 keV and 10.3 keV, Kα and Kβ lines superimposed on a multi-keV Bremsstrahlung continuum. This source was generated by a 50fs duration, 1 kHz, 2W, high intensity Ti:Sapphire laser. We will discuss the extension of this source to higher powers and higher repetition rates, providing harder x-ray emission, with the incorporation of pulse-shaping and other techniques to enhance the x-ray conversion efficiency. Using the same liquid target technology, we have also demonstrated the generation of forward-going sub-MeV protons from a 10 μm liquid water target at 1 kHz repetition rates. kHz sources of high energy ions will find many applications in time-resolved particle interaction studies, as well as lead to the efficient generation of short-lived isotopes for use in nuclear medicine and other applications. The protons were detected with CR-39 track detectors both in the forward and backward directions up to energies of ~500 keV. As the intensity of compact high repetition-rate lasers sources increase, we can expect improvements in the energy, conversion efficiency and directionality to occur. The impact of these developments on a number of fields will be discussed. As compact

  12. 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.

  13. A Compact X-Ray System for Support of High Throughput Crystallography

    NASA Technical Reports Server (NTRS)

    Ciszak, Ewa; Gubarev, Mikhail; Gibson, Walter M.; Joy, Marshall K.; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    Standard x-ray systems for crystallography rely on massive generators coupled with optics that guide X-ray beams onto the crystal sample. Optics for single-crystal diffractometry include total reflection mirrors, polycapillary optics or graded multilayer monochromators. The benefit of using polycapillary optic is that it can collect x-rays over tile greatest solid angle, and thus most efficiently, utilize the greatest portion of X-rays emitted from the Source, The x-ray generator has to have a small anode spot, and thus its size and power requirements can be substantially reduced We present the design and results from the first high flux x-ray system for crystallography that combine's a microfocus X-ray generator (40microns FWHM Spot size at a power of 45 W) and a collimating, polycapillary optic. Diffraction data collected from small test crystals with cell dimensions up to 160A (lysozyme and thaumatin) are of high quality. For example, diffraction data collected from a lysozyme crystal at RT yielded R=5.0% for data extending to 1.70A. We compare these results with measurements taken from standard crystallographic systems. Our current microfocus X-ray diffraction system is attractive for supporting crystal growth research in the standard crystallography laboratory as well as in remote, automated crystal growth laboratory. Its small volume, light-weight, and low power requirements are sufficient to have it installed in unique environments, i.e.. on-board International Space Station.

  14. Development of a stationary chest tomosynthesis system using carbon nanotube x-ray source array

    NASA Astrophysics Data System (ADS)

    Shan, Jing

    X-ray imaging system has shown its usefulness for providing quick and easy access of imaging in both clinic settings and emergency situations. It greatly improves the workflow in hospitals. However, the conventional radiography systems, lacks 3D information in the images. The tissue overlapping issue in the 2D projection image result in low sensitivity and specificity. Both computed tomography and digital tomosynthesis, the two conventional 3D imaging modalities, requires a complex gantry to mechanically translate the x-ray source to various positions. Over the past decade, our research group has developed a carbon nanotube (CNT) based x-ray source technology. The CNT x-ray sources allows compacting multiple x-ray sources into a single x-ray tube. Each individual x-ray source in the source array can be electronically switched. This technology allows development of stationary tomographic imaging modalities without any complex mechanical gantries. The goal of this work is to develop a stationary digital chest tomosynthesis (s-DCT) system, and implement it for a clinical trial. The feasibility of s-DCT was investigated. It is found that the CNT source array can provide sufficient x-ray output for chest imaging. Phantom images have shown comparable image qualities as conventional DCT. The s-DBT system was then used to study the effects of source array configurations and tomosynthesis image quality, and the feasibility of a physiological gated s-DCT. Using physical measures for spatial resolution, the 2D source configuration was shown to have improved depth resolution and comparable in-plane resolution. The prospective gated tomosynthesis images have shown substantially reduction of image blur associated with lung motions. The system was also used to investigate the feasibility of using s-DCT as a diagnosis and monitoring tools for cystic fibrosis patients. A new scatter reduction methods for s-DCT was also studied. Finally, a s-DCT system was constructed by

  15. A compact high-resolution X-ray powder diffractometer

    PubMed Central

    Fewster, Paul F.; Trout, David R. D.

    2013-01-01

    A new powder diffractometer operating in transmission mode is described. It can work as a rapid very compact instrument or as a high-resolution instrument, and the sample preparation is simplified. The incident beam optics create pure Cu Kα1 radiation, giving rise to peak widths of ∼0.1° in 2θ in compact form with a sample-to-detector minimum radius of 55 mm, reducing to peak widths of <0.05° in high-resolution mode by increasing the detector radius to 240 mm. The resolution of the diffractometer is shown to be governed by a complex mixture of angular divergence, sample size, diffraction effects and the dimensions of the detector pixels. The data can be collected instantaneously, which combined with trivial sample preparation and no sample alignment, makes it a suitable method for very rapid phase identification. As the detector is moved further from the sample, the angular step from the pixel dimension is reduced and the resolution improves significantly for very detailed studies, including structure determination and analysis of the microstructure. The advantage of this geometry is that the resolution of the diffractometer can be calculated precisely and the instrumental artefacts can be analysed easily without a sample present. The performance is demonstrated with LaB6 and paracetamol, and a critical appraisal of the uncertainties in the measurements is presented. The instantaneous data collection offers possibilities in dynamic experiments. PMID:24282331

  16. Compact high-resolution differential interference contrast soft x-ray microscopy

    SciTech Connect

    Bertilson, Michael C.; Hofsten, Olov von; Lindblom, Magnus; Hertz, Hans M.; Vogt, Ulrich

    2008-02-11

    We demonstrate high-resolution x-ray differential interference contrast (DIC) in a compact soft x-ray microscope. Phase contrast imaging is enabled by the use of a diffractive optical element objective which is matched to the coherence conditions in the microscope setup. The performance of the diffractive optical element objective is evaluated in comparison with a normal zone plate by imaging of a nickel siemens star pattern and linear grating test objects. Images obtained with the DIC optic exhibit typical DIC enhancement in addition to the normal absorption contrast. Contrast transfer functions based on modulation measurements in the obtained images show that the DIC optic gives a significant increase in contrast without reducing the spatial resolution. The phase contrast operation mode now available for our compact soft x-ray microscope will be a useful tool for future studies of samples with low absorption contrast.

  17. 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.

  18. 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.

  19. Continuum and line spectra of degenerate dwarf X-ray sources

    NASA Technical Reports Server (NTRS)

    Lamb, D. Q.

    1981-01-01

    Recent observations of X-ray sources are summarized. Unresolved issues concerning these sources are discussed and an outline of the kinds of X-ray observations that would best advance the understanding of these sources is presented.

  20. Galactic bulge X-ray burst sources from disrupted globular clusters?

    NASA Technical Reports Server (NTRS)

    Grindlay, J. E.; Hertz, P.

    1985-01-01

    The origin of the bright galactic bulge X-ray sources, or GX sources, is unclear despite intensive study for the past 15 years. It is suggested that the fact that many (or most) of the GX sources are X-ray burst sources (GXRBS) and are otherwise apparently identical to the luminous X-ray sources found in globular cluster cores implies that they too may have a globular cluster origin. The possibility that the compact X-ray binaries found in globulars are ejected is constrained by observations of CVs in and out of clusters. The GXRBS are instead hypothesized to have been formed by capture processes in globular clusters which have now largely been disrupted by repeated tidal stripping and shocking in the galactic plane. A statistical analysis of the 12 GXRBS which have precise positions from Einstein and/or optical (or radio) observations indicate that it is probably significant that a bright, of less than about 19, G or K star is found within the error circle (3 arcmin radius) in four cases. These may be surviving giants in a disrupted globular cluster core. Implications for globular cluster evolution and the GXRBS themselves are discussed.

  1. 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.

  2. Characterization by X-ray tomography of granulated alumina powder during in situ die compaction

    SciTech Connect

    Cottrino, Sandrine; Jorand, Yves Maire, Eric; Adrien, Jérôme

    2013-07-15

    Compaction process, the aim of which being to obtain green bodies with low porosity and small size, is often used before sintering treatment. Prior to die filling, the ceramic powder is generally granulated to improve flowability. However during compaction, density heterogeneity and critical size defects may appear due to intergranule and granule-die wall frictions. In this work, the influence of granule formulation on the compact morphology has been studied. To do so, a compaction setup was installed inside an X-ray tomography equipment so that the evolution of the compact morphology could be analysed during the whole compaction process. We have demonstrated that high humidity rate and the addition of binder in the granule formulation increase density heterogeneity and generate larger defects. - Highlights: • An original compaction set up was installed inside an X-Ray tomography equipment. • The compaction process of granulated ceramic powder is imaged. • The compact green microstructure is quantified and related to the compaction stages. • The most detrimental defects of dry-pressed parts are caused by hollow granules. • Formulations without binder allow a reduction of the number of large defects.

  3. 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.

  4. 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.

  5. On the evolutionary status of bright, low-mass X-ray sources

    NASA Technical Reports Server (NTRS)

    Webbink, R. F.; Rappaport, S.; Savonije, G. J.

    1983-01-01

    A model of bright, low-mass X-ray binaries is proposed which features a lower giant-branch star losing mass on a nuclear time scale to an accreting compact companion. Simple numerical models show that mass transfer rates equal to or greater than 10 to the -9th solar masses per yr are sustained at very nearly a constant rate until the envelope of the donor star is exhausted. The model predicts orbital periods in the range 1-200 days and X-ray to optical luminosity ratios Lx/Lopt = 200-1000 for these sources. It accounts in a natural way for the large fraction of the total galactic bulge luminosity emitted by a few bright (10 to the 37th erg/s or greater) sources. It also accords very well with the observed X-ray and optical properties of the halo source Cyg X-2 and also with those of 2S 0921-63, provided this latter system contains a massive accreting white dwarf rather than a neutron star. Problems of the prior evolution of low-mass X-ray sources are also briefly delineated.

  6. 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.

  7. Supersoft X-ray sources: the role of V Sge

    NASA Astrophysics Data System (ADS)

    Simon, Vojtech; Mattei, Janet A.

    2007-07-01

    V Sge is one of a few known super-soft X-ray sources (SSXSs) located in our Galaxy and is the representative of the V Sge class. Here we concentrate on its long-term optical activity (mostly transitions between high and low states, clustering in so-called active segments). We show that cycles are often apparent in such transitions but their length undergoes large, often gradual variations. We give the implications for the accretion wind evolution, modeled by Hachisu & Kato (2003). We also analyze the color indices and absolute magnitudes of V Sge and compare them with those of ´classicaĺ SSXSs with the orbital period shorter than 4 d. This approach helps compare the properties and configuration of the medium, on which soft X-rays are reprocessed in these systems. The specific properties of SSXSs, as regards their optical activity, absolute magnitudes and colors, can be the promising tools for the search for such systems in the optical and near UV passbands. SSXSs yet undetected in the X-ray passband because of absorption thus can be revealed by the photometric method.

  8. 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.

  9. Development of a hard x-ray focal plane compton polarimeter: a compact polarimetric configuration with scintillators and Si photomultipliers

    NASA Astrophysics Data System (ADS)

    Chattopadhyay, T.; Vadawale, S. V.; Goyal, S. K.; Mithun, N. P. S.; Patel, A. R.; Shukla, R.; Ladiya, T.; Shanmugam, M.; Patel, V. R.; Ubale, G. P.

    2016-02-01

    X-ray polarization measurement of cosmic sources provides two unique parameters namely degree and angle of polarization which can probe the emission mechanism and geometry at close vicinity of the compact objects. Specifically, the hard X-ray polarimetry is more rewarding because the sources are expected to be intrinsically highly polarized at higher energies. With the successful implementation of Hard X-ray optics in NuSTAR, it is now feasible to conceive Compton polarimeters as focal plane detectors. Such a configuration is likely to provide sensitive polarization measurements in hard X-rays with a broad energy band. We are developing a focal plane hard X-ray Compton polarimeter consisting of a plastic scintillator as active scatterer surrounded by a cylindrical array of CsI(Tl) scintillators. The scatterer is 5 mm diameter and 100 mm long plastic scintillator (BC404) viewed by normal PMT. The photons scattered by the plastic scatterer are collected by a cylindrical array of 16 CsI(Tl) scintillators (5 mm × 5 mm × 150 mm) which are read by Si Photomultiplier (SiPM). Use of the new generation SiPMs ensures the compactness of the instrument which is essential for the design of focal plane detectors. The expected sensitivity of such polarimetric configuration and complete characterization of the plastic scatterer, specially at lower energies have been discussed in [11, 13]. In this paper, we characterize the CsI(Tl) absorbers coupled to SiPM. We also present the experimental results from the fully assembled configuration of the Compton polarimeter.

  10. 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.

  11. The nuclear X-ray source in NGC 3628: A strange active galactic nucleus or the most luminous high-mass X-ray binary known?

    NASA Technical Reports Server (NTRS)

    Dahlem, Michael; Heckman, Timothy M.; Fabbiano, Giuseppina

    1995-01-01

    After 12 years, during which its unabsorbed soft X-ray flux in the 0.1-2.0 keV band was almost constant at about f(sub x) approximately 10(exp -12) ergs/s/sq cm, the compact nuclear source in NGC 3628 was not detected in one of our ROSAT observations, with a limiting sensitivity of f(sub x) approximately 5 x 10(exp -14) ergs/s/sq cm. Our data can be explained in two ways. The source is either the most massive X-ray binary known so far, with a greater than and approximately equal to 75 solar mass black hole, or an unusual low-luminosity Active Galactic Nuclei (AGN). The X-ray spectrum is typical of a high-mass X-ray binary, while the luminosity of the source of L(sub x) is approximately equal to 10(exp 40) ergs/s is more similar to those of low-luminosity AGNs. If it is an AGN, variable obscuration might explain the observed light curve.

  12. X-Ray Counterparts of Puzzling Gev-Tev Sources

    NASA Astrophysics Data System (ADS)

    Kargaltsev, Oleg

    2014-09-01

    We propose to look for X-ray counterparts of the extended TeV source HESS J1616-508 that may also have been detected with Fermi at GeV energies. The nature of the source and the connection between the TeV source and the nearby GeV sources are unknown. It has been suggested that it may be a relic plerion powered by the offset PSR J1617-5055, but a deep Chandra observation of this pulsar and its wind nebula has not confirmed this hypothesis. To understand the nature of this long-standing "dark accelerator", we propose to observe the GeV sources (which could be young pulsars) and another nearby young pulsar (J1614-5048) to check whether or not they could supply relativistic particles and power the TeV source. We will also explore the nature of the GeV sources.

  13. 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.

  14. An ultraluminous X-ray source powered by an accreting neutron star.

    PubMed

    Bachetti, M; Harrison, F A; Walton, D J; Grefenstette, B W; Chakrabarty, D; Fürst, F; Barret, D; Beloborodov, A; Boggs, S E; Christensen, F E; Craig, W W; Fabian, A C; Hailey, C J; Hornschemeier, A; Kaspi, V; Kulkarni, S R; Maccarone, T; Miller, J M; Rana, V; Stern, D; Tendulkar, S P; Tomsick, J; Webb, N A; Zhang, W W

    2014-10-01

    The majority of ultraluminous X-ray sources are point sources that are spatially offset from the nuclei of nearby galaxies and whose X-ray luminosities exceed the theoretical maximum for spherical infall (the Eddington limit) onto stellar-mass black holes. Their X-ray luminosities in the 0.5-10 kiloelectronvolt energy band range from 10(39) to 10(41) ergs per second. Because higher masses imply less extreme ratios of the luminosity to the isotropic Eddington limit, theoretical models have focused on black hole rather than neutron star systems. The most challenging sources to explain are those at the luminous end of the range (more than 10(40) ergs per second), which require black hole masses of 50-100 times the solar value or significant departures from the standard thin disk accretion that powers bright Galactic X-ray binaries, or both. Here we report broadband X-ray observations of the nuclear region of the galaxy M82 that reveal pulsations with an average period of 1.37 seconds and a 2.5-day sinusoidal modulation. The pulsations result from the rotation of a magnetized neutron star, and the modulation arises from its binary orbit. The pulsed flux alone corresponds to an X-ray luminosity in the 3-30 kiloelectronvolt range of 4.9 × 10(39) ergs per second. The pulsating source is spatially coincident with a variable source that can reach an X-ray luminosity in the 0.3-10 kiloelectronvolt range of 1.8 × 10(40) ergs per second. This association implies a luminosity of about 100 times the Eddington limit for a 1.4-solar-mass object, or more than ten times brighter than any known accreting pulsar. This implies that neutron stars may not be rare in the ultraluminous X-ray population, and it challenges physical models for the accretion of matter onto magnetized compact objects. PMID:25297433

  15. An ultraluminous X-ray source powered by an accreting neutron star.

    PubMed

    Bachetti, M; Harrison, F A; Walton, D J; Grefenstette, B W; Chakrabarty, D; Fürst, F; Barret, D; Beloborodov, A; Boggs, S E; Christensen, F E; Craig, W W; Fabian, A C; Hailey, C J; Hornschemeier, A; Kaspi, V; Kulkarni, S R; Maccarone, T; Miller, J M; Rana, V; Stern, D; Tendulkar, S P; Tomsick, J; Webb, N A; Zhang, W W

    2014-10-01

    The majority of ultraluminous X-ray sources are point sources that are spatially offset from the nuclei of nearby galaxies and whose X-ray luminosities exceed the theoretical maximum for spherical infall (the Eddington limit) onto stellar-mass black holes. Their X-ray luminosities in the 0.5-10 kiloelectronvolt energy band range from 10(39) to 10(41) ergs per second. Because higher masses imply less extreme ratios of the luminosity to the isotropic Eddington limit, theoretical models have focused on black hole rather than neutron star systems. The most challenging sources to explain are those at the luminous end of the range (more than 10(40) ergs per second), which require black hole masses of 50-100 times the solar value or significant departures from the standard thin disk accretion that powers bright Galactic X-ray binaries, or both. Here we report broadband X-ray observations of the nuclear region of the galaxy M82 that reveal pulsations with an average period of 1.37 seconds and a 2.5-day sinusoidal modulation. The pulsations result from the rotation of a magnetized neutron star, and the modulation arises from its binary orbit. The pulsed flux alone corresponds to an X-ray luminosity in the 3-30 kiloelectronvolt range of 4.9 × 10(39) ergs per second. The pulsating source is spatially coincident with a variable source that can reach an X-ray luminosity in the 0.3-10 kiloelectronvolt range of 1.8 × 10(40) ergs per second. This association implies a luminosity of about 100 times the Eddington limit for a 1.4-solar-mass object, or more than ten times brighter than any known accreting pulsar. This implies that neutron stars may not be rare in the ultraluminous X-ray population, and it challenges physical models for the accretion of matter onto magnetized compact objects.

  16. Recent results of X-ray observations from OSO-7 and SAS-3

    NASA Technical Reports Server (NTRS)

    Clark, G. W.

    1978-01-01

    Recent observations bearing on the nature of compact X-ray sources obtained from the MIT instruments aboard OSO-7 and SAS-3 are discussed. Results on the X-ray sky survey, new ultralow-energy X-ray sources, X-ray sources in globular clusters, slow X-ray pulsars, and variability and position of compact X-ray sources in Cen A are discussed. Descriptions of the satellite-borne X-ray instruments are provided.

  17. Exotic sources of x-rays for iodine K-edge angiography

    SciTech Connect

    Carr, R.

    1993-08-01

    Digital Subtractive Angiography (DSA) has been performed to image human coronary arteries using wiggler radiation from electron storage rings. The significant medical promise of this procedure motivates the development of smaller and less costly x-ray sources. Several exotic sources are candidates for consideration, using effects such as Cherenkov, channeling, coherent bremsstrahlung, laser backscattering, microundulator, parametric, Smith-Purcell, and transition radiation. In this work we present an analysis of these effects as possible sources of intense x-rays at the iodine K-edge at 33.169 key. The criteria we use are energy, efficiency, flux, optical properties, and technical realizability. For each of the techniques, we find that they suffer either from low flux, a low energy cutoff, target materials heating, too high electron beam energy requirement, optical mismatch to angiography, or a combination of these. We conclude that the foreseeable state-of-the-art favors a compact storage ring design.

  18. Compact 'diode-based' multi-energy soft x-ray diagnostic for NSTX

    SciTech Connect

    Tritz, K.; Clayton, D. J.; Stutman, D.; Finkenthal, M.

    2012-10-15

    A novel and compact, diode-based, multi-energy soft x-ray (ME-SXR) diagnostic has been developed for the National Spherical Tokamak Experiment. The new edge ME-SXR system tested on NSTX consists of a set of vertically stacked diode arrays, each viewing the plasma tangentially through independent pinholes and filters providing an overlapping view of the plasma midplane which allows simultaneous SXR measurements with coarse sub-sampling of the x-ray spectrum. Using computed x-ray spectral emission data, combinations of filters can provide fast (>10 kHz) measurements of changes in the electron temperature and density profiles providing a method to 'fill-in' the gaps of the multi-point Thomson scattering system.

  19. X-Ray Spectral and Temporal Studies of the Ultra-Compact System X1916-05

    NASA Technical Reports Server (NTRS)

    Grindlay, Jonathan E.

    1998-01-01

    Rossi x-ray timing Explorer (RXTE) Cycle 1 data on the ultra-compact low mass x- ray binary (LMXB) X1916-05 is analyzed. In this current report, the scientific objectives of this investigation of hard x-ray studies of bursters and the results achieved are summarized. The scientific objectives are: (1) Period of the x-ray dips in X1916-05; (2) Phase stability of the x-ray dip period; (3) Spectral break energy and its dependence on mass transfer rate; and (4) Qpos detected from this LMXB. A list of published papers resulted from this project is also included.

  20. X-band RF gun and linac for medical Compton scattering X-ray source

    NASA Astrophysics Data System (ADS)

    Dobashi, Katsuhito; Uesaka, Mitsuru; Fukasawa, Atsushi; Sakamoto, Fumito; Ebina, Futaro; Ogino, Haruyuki; Urakawa, Junji; Higo, Toshiyasu; Akemoto, Mitsuo; Hayano, Hitoshi; Nakagawa, Keiichi

    2004-12-01

    Compton scattering hard X-ray source for 10-80 keV are under construction using the X-band (11.424 GHz) electron linear accelerator and YAG laser at Nuclear Engineering Research laboratory, University of Tokyo. This work is a part of the national project on the development of advanced compact medical accelerators in Japan. National Institute for Radiological Science is the host institute and U.Tokyo and KEK are working for the X-ray source. Main advantage is to produce tunable monochromatic hard (10-80 keV) X-rays with the intensities of 108-1010 photons/s (at several stages) and the table-top size. Second important aspect is to reduce noise radiation at a beam dump by adopting the deceleration of electrons after the Compton scattering. This realizes one beamline of a 3rd generation SR source at small facilities without heavy shielding. The final goal is that the linac and laser are installed on the moving gantry. We have designed the X-band (11.424 GHz) traveling-wave-type linac for the purpose. Numerical consideration by CAIN code and luminosity calculation are performed to estimate the X-ray yield. X-band thermionic-cathode RF-gun and RDS(Round Detuned Structure)-type X-band accelerating structure are applied to generate 50 MeV electron beam with 20 pC microbunches (104) for 1 microsecond RF macro-pulse. The X-ray yield by the electron beam and Q-switch Nd:YAG laser of 2 J/10 ns is 107 photons/RF-pulse (108 photons/sec at 10 pps). We design to adopt a technique of laser circulation to increase the X-ray yield up to 109 photons/pulse (1010 photons/s). 50 MW X-band klystron and compact modulator have been constructed and now under tuning. The construction of the whole system has started. X-ray generation and medical application will be performed in the early next year.

  1. 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.

  2. Total-reflection X-ray fluorescence analysis using special X-ray sources

    NASA Astrophysics Data System (ADS)

    Wobrauschek, P.; Kregsamer, P.; Ladisich, W.; Rieder, R.; Streli, C.

    1993-02-01

    The parameter variations of exciting radiation, like spectral distribution, intensity, brilliance, polarization and the phenomenon of X-ray total reflection, leads to improved lower limits of detection (LLD) in XRF. Observations and results from experiments performed with different X-ray tubes such as fine focus Cu and Mo anodes, a specially designed Au anode operated with 100 kV and high power rotating anodes are reported. Results from measurements with monochromatic X-rays tuned with a multilayer structure as well as the use of polarized X-rays from the synchrotron will be shown. All developed measuring devices will be described in terms of their recent design features showing the possible geometric arrangements denned by the beam-reflector-detector position. The extrapolated detection limits for the K-shell excitation of rare earth elements are in the region of 0.3 ng, for medium Z elements in the pg range and for optimized conditions, with a rotating Cu anode, 170 fg for Mn are achieved corresponding to the pg g -1 (ppt) concentration level.

  3. 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.

  4. Two Eclipsing Ultraluminous X-Ray Sources in M51

    NASA Astrophysics Data System (ADS)

    Urquhart, R.; Soria, R.

    2016-11-01

    We present the discovery, from archival Chandra and XMM-Newton data, of X-ray eclipses in two ultraluminous X-ray sources (ULXs), located in the same region of the galaxy M51: CXOM51 J132940.0+471237 (ULX-1, for simplicity) and CXOM51 J132939.5+471244 (ULX-2). Three eclipses were detected for ULX-1 and two for ULX-2. The presence of eclipses puts strong constraints on the viewing angle, suggesting that both ULXs are seen almost edge-on and are certainly not beamed toward us. Despite the similar viewing angles and luminosities ({L}{{X}}≈ 2× {10}39 erg s‑1 in the 0.3–8 keV band for both sources), their X-ray properties are different. ULX-1 has a soft spectrum, well fitted by Comptonization emission from a medium with electron temperature {{kT}}e≈ 1 {keV}. ULX-2 is harder, well fitted by a slim disk with {{kT}}{in}≈ 1.5–1.8 keV and normalization consistent with a ∼10 M ⊙ black hole. ULX-1 has a significant contribution from multi-temperature thermal-plasma emission ({L}{{X},{mekal}}≈ 2× {10}38 erg s‑1). About 10% of this emission remains visible during the eclipses, proving that the emitting gas comes from a region slightly more extended than the size of the donor star. From the sequence and duration of the Chandra observations in and out of eclipse, we constrain the binary period of ULX-1 to be either ≈ 6.3 days, or ≈12.5–13 days. If the donor star fills its Roche lobe (a plausible assumption for ULXs), both cases require an evolved donor, most likely a blue supergiant, given the young age of the stellar population in that Galactic environment.

  5. Classification of compact binaries: an X-ray analog to the HR diagram

    NASA Astrophysics Data System (ADS)

    Dil Vrtilek, Saeqa; Raymond, John C.; Gopalan, Giri; Boroson, Bram Seth; Bornn, Luke

    2016-06-01

    X-ray binary systems (XRBs), when examined in an appropriate coordinate system derived from X-ray spectral and intensity information, appear to cluster based on their compact object type. We introduce such a coordinate system, in which two coordinates are hardness ratios and the third is a broadband X-ray intensity. In Gopalan, Vrtilek, & Bornn (2015) we developed a Bayesian statistical model that estimates the probability that an XRB contains a black hole, non-pulsing neutron star, or pulsing neutron star, depending on its location in our coordinate space. In particular, we utilized a latent variable model in which the latent variables follow a Gaussian process prior distribution. Here we expand our work to incorporate systems where the compact object is a white dwarf: cataclysmic variables (CVs). The fact that the CVs also fall into a location spatially distinct from the other XRB types supports the use of X-ray color-color-intensity diagrams as 3-dimensional analogs to the Hertzsprung-Russell diagram for normal stars.

  6. The Galactic plane at faint X-ray fluxes - I. Properties and characteristics of the X-ray source population

    NASA Astrophysics Data System (ADS)

    Warwick, R. S.; Pérez-Ramírez, D.; Byckling, K.

    2011-05-01

    We investigate the serendipitous X-ray source population revealed in XMM-Newton observations targeted in the Galactic plane within the region 315° < l < 45° and |b| < 2?. Our study focuses on a sample of 2204 X-ray sources at intermediate to faint fluxes, which were detected in a total of 116 XMM-Newton fields and are listed in the Second XMM-Newton Serendipitous Source Catalog. We characterize each source as spectrally soft or hard on the basis of whether the bulk of the recorded counts have energies below or above 2 keV and find that the sample divides roughly equally (56 per cent:44 per cent) into these soft and hard categories. The X-ray spectral form underlying the soft sources may be represented as either a power-law continuum with Γ˜ 2.5 or a thermal spectrum with kT˜ 0.5 keV, with NH ranging from 1020 to 1022 cm-2. For the hard sources, a significantly harder continuum form is likely, that is, Γ˜ 1, with NH= 1022-1024 cm-2. For ˜50 per cent of the hard sources, the inferred column density is commensurate with the total Galactic line-of-sight value; many of these sources will be located at significant distances across the Galaxy, implying a hard-band luminosity LX > 1032 erg s-1, whereas some will be extragalactic interlopers. A high fraction (≳90 per cent) of the soft sources have potential near-infrared (NIR) (Two-Micron All-Sky Survey and/or United Kingdom Infrared Deep Sky Survey) counterparts inside their error circles, consistent with the dominant soft-X-ray-source population being relatively nearby coronally-active stars. These stellar counterparts are generally brighter than J= 16, a brightness cut-off which corresponds to the saturation of the X-ray coronal emission at LX= 10-3 Lbol. In contrast, the success rate in finding likely IR counterparts to the hard X-ray sample is no more than ≈15 per cent down to J= 16 and ≈25 per cent down to J= 20, set against a rapidly rising chance coincidence rate. The make-up of the hard-X-ray-source

  7. Relativistic baryonic jets from an ultraluminous supersoft X-ray source.

    PubMed

    Liu, Ji-Feng; Bai, Yu; Wang, Song; Justham, Stephen; Lu, You-Jun; Gu, Wei-Min; Liu, Qing-Zhong; Di Stefano, Rosanne; Guo, Jin-Cheng; Cabrera-Lavers, Antonio; Álvarez, Pedro; Cao, Yi; Kulkarni, Shri

    2015-12-01

    The formation of relativistic jets by an accreting compact object is one of the fundamental mysteries of astrophysics. Although the theory is poorly understood, observations of relativistic jets from systems known as microquasars (compact binary stars) have led to a well established phenomenology. Relativistic jets are not expected to be produced by sources with soft or supersoft X-ray spectra, although two such systems are known to produce relatively low-velocity bipolar outflows. Here we report the optical spectra of an ultraluminous supersoft X-ray source (ULS) in the nearby galaxy M81 (M81 ULS-1; refs 9, 10). Unexpectedly, the spectra show blueshifted, broad Hα emission lines, characteristic of baryonic jets with relativistic speeds. These time-variable emission lines have projected velocities of about 17 per cent of the speed of light, and seem to be similar to those from the prototype microquasar SS 433 (refs 11, 12). Such relativistic jets are not expected to be launched from white dwarfs, and an origin from a black hole or a neutron star is hard to reconcile with the persistence of M81 ULS-1's soft X-rays. Thus the unexpected presence of relativistic jets in a ULS challenges canonical theories of jet formation, but might be explained by a long-speculated, supercritically accreting black hole with optically thick outflows. PMID:26605521

  8. Relativistic baryonic jets from an ultraluminous supersoft X-ray source.

    PubMed

    Liu, Ji-Feng; Bai, Yu; Wang, Song; Justham, Stephen; Lu, You-Jun; Gu, Wei-Min; Liu, Qing-Zhong; Di Stefano, Rosanne; Guo, Jin-Cheng; Cabrera-Lavers, Antonio; Álvarez, Pedro; Cao, Yi; Kulkarni, Shri

    2015-12-01

    The formation of relativistic jets by an accreting compact object is one of the fundamental mysteries of astrophysics. Although the theory is poorly understood, observations of relativistic jets from systems known as microquasars (compact binary stars) have led to a well established phenomenology. Relativistic jets are not expected to be produced by sources with soft or supersoft X-ray spectra, although two such systems are known to produce relatively low-velocity bipolar outflows. Here we report the optical spectra of an ultraluminous supersoft X-ray source (ULS) in the nearby galaxy M81 (M81 ULS-1; refs 9, 10). Unexpectedly, the spectra show blueshifted, broad Hα emission lines, characteristic of baryonic jets with relativistic speeds. These time-variable emission lines have projected velocities of about 17 per cent of the speed of light, and seem to be similar to those from the prototype microquasar SS 433 (refs 11, 12). Such relativistic jets are not expected to be launched from white dwarfs, and an origin from a black hole or a neutron star is hard to reconcile with the persistence of M81 ULS-1's soft X-rays. Thus the unexpected presence of relativistic jets in a ULS challenges canonical theories of jet formation, but might be explained by a long-speculated, supercritically accreting black hole with optically thick outflows.

  9. Lensless imaging using broadband X-ray sources

    NASA Astrophysics Data System (ADS)

    Abbey, Brian; Whitehead, Lachlan W.; Quiney, Harry M.; Vine, David J.; Cadenazzi, Guido A.; Henderson, Clare A.; Nugent, Keith A.; Balaur, Eugeniu; Putkunz, Corey T.; Peele, Andrew G.; Williams, G. J.; McNulty, I.

    2011-07-01

    High-resolution X-ray imaging techniques using optical elements such as zone plates are widely used for viewing the internal structure of samples in exquisite detail. The resolution attainable is ultimately limited by the manufacturing tolerances for the optics. Combining ideas from crystallography and holography, this limit may be surpassed by the method of coherent diffractive imaging (CDI). Although CDI shows particular promise in applications involving X-ray free-electron lasers, it is also emerging as an important new technique for imaging at third-generation synchrotrons. The limited coherent output of these sources, however, is a significant barrier to obtaining shorter exposure times. A fundamental assumption of coherent diffractive imaging is that the incident light is well-approximated by a single optical frequency. In this Letter, we demonstrate the first experimental realization of `polyCDI', using a broadband source to achieve a factor of 60 reduction in the exposure time over quasi-monochromatic coherent diffractive imaging.

  10. 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.

  11. High-reflectivity Cr/Sc multilayer condenser for compact soft x-ray microscopy

    SciTech Connect

    Stollberg, H.; Yulin, S.; Takman, P. A. C.; Hertz, H. M.

    2006-12-15

    The condenser is a critical component in compact water-window x-ray microscopes as it influences the exposure time via its efficiency and the resolution via its numerical aperture. Normal-incidence multilayer mirrors can reach large geometrical collection efficiencies and match the numerical aperture of the zone plate but require advanced processing for high total reflectivity. In the present article we demonstrate large-diameter normal-incidence spherical Cr/Sc multilayer condensers with high and uniform reflectivity. Dc-magnetron sputtering was used to deposit 300 bilayers of Cr/Sc with a predetermined d-spacing matching the {lambda}=3.374 nm operating wavelength on spherical substrates. The mirrors show a uniform reflectivity of {approx}3% over the full 58 mm diameter condenser area. With these mirrors an improvement in exposure time by a factor of 10 was achieved, thereby improving the performance of the compact x-ray microscope significantly.

  12. Kilohertz sources of hard x rays and fast ions with femtosecond laser plasmas

    NASA Astrophysics Data System (ADS)

    Thoss, A.; Richardson, M.; Korn, G.; Faubel, M.; Stiel, H.; Vogt, U.; Elsaesser, T.

    2003-01-01

    We demonstrate a new, stable, kilohertz femtosecond laser plasma source of hard-x-ray continuum and Kα emission that uses a microscopic liquid jet target that is continuous and debris free. Plasmas produced by ultrashort (50-fs) intense laser pulses from a fine (10-30-μm diameter) liquid Ga jet emit bright 9.3- and 10.3-keV Kα and Kβ lines superimposed on a multikilovolt bremmstrahlung continuum. Kilohertz femtosecond x-ray sources will find many applications in time-resolved x-ray diffraction and microscopy studies. As high-intensity lasers become more compact and operate at increasingly high repetition-rates, they require a target configuration that is both repeatable from shot to shot and debris free. Our target provides a pristine, unperturbed filament surface at rates >100 kHz. A number of liquid metal targets are considered. We show the hard-x-ray spectrum described above. The source was generated by a 50-fs-duration, 1-kHz, 2-W, high-intensity Ti:sapphire laser. Using the same technology, we also generate forward-going sub-mega-electron-volt (sub-MeV) protons from a 10-μm liquid water target at 1-kHz repetition rates. Kilohertz sources of high-energy ions will find many applications in time-resolved particle interaction studies and will lead to efficient generation of short-lived isotopes for use in nuclear medicine and other applications. The protons were detected with CR-39 track detectors in both the forward and the backward directions up to energies of ~500 keV. As the intensity of compact high-repetition-rate lasers sources increases, we can expect improvements in the energy, conversion efficiency, and directionality to occur. The effect of these developments is discussed. As compact, high-repetition-rate femtosecond laser technology reaches focused intensities of ~1019 W/cm2, many new applications of high-repetition-rate hard-x-ray and MeV ion sources will become practical.

  13. 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.

  14. 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

  15. Observations of soft X-ray emission and plasma dynamics of a compact capillary discharge operated in xenon

    SciTech Connect

    Valenzuela, J. C.; Wyndham, E. S.; Favre, M.; Chuaqui, H.

    2013-09-15

    We report observations of a low stored energy, low inductance compact capillary discharge operated in xenon. Even though the stored electrical energy is less than 1 J, significant output in the optical windows at 110 and 135 Å is measured. The soft X-ray emission is time-resolved and the conversion energy of the source is obtained. A lower bound to the conversion efficiency at 110 Å ± 2% and 135 Å ± 1% of 3.6% and 1.6% is obtained, respectively. The use of moiré-schlieren optical diagnostic allows the evolution of the line electron density. In particular, we observe a significant degree of compression in a tight on axis pinch as well as radial compression waves. The temporal evolution of the X-ray emission, which occurs during the current reversal and later, is discussed in relation to work in argon discharges and in relation to model calculations.

  16. An X-ray View of the Zoo of Compact Objects and Associated Supernova Remnants

    NASA Astrophysics Data System (ADS)

    Safi-Harb, Samar

    2015-08-01

    Core-collapse explosions of massive stars leave behind some of the most exotic compact objects in the Universe. These include: rotation-powered pulsars like the Crab, powering pulsar wind nebulae (PWNe) observed across the electromagnetic spectrum; highly magnetized neutron stars ("magnetars") shining or bursting at high-energies; and X-ray emitting “Central Compact Objects” (CCOs) with intrinsic properties and emission mechanism that remain largely unknown. I will highlight this observed diversity of compact stellar remnants from an X-ray perspective, and address the connection between their properties and those of their hosting supernova remnants (SNRs). In particular I will highlight topics related to their formation and evolution, including: 1) which supernovae make magnetars and the shell-less PWNe?, 2) what can we learn from the apparent age discrepancy between SNRs and their associated pulsars? I will conclude with prospects for observations of SNRs with the upcoming ASTRO-H X-ray mission. The unprecedented spectral resolution on board of ASTRO-H’s micro-calorimeter will particularly open a new discovery window for supernova progenitors' science.

  17. 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.

  18. INTRAGROUP AND GALAXY-LINKED DIFFUSE X-RAY EMISSION IN HICKSON COMPACT GROUPS

    SciTech Connect

    Desjardins, Tyler D.; Gallagher, Sarah C.; Tzanavaris, Panayiotis; Hornschemeier, Ann E.; Brandt, William N.; Charlton, Jane C.; Garmire, Gordon P.; Gronwall, Caryl; Konstantopoulos, Iraklis S.; Johnson, Kelsey E.; Zabludoff, Ann I.

    2013-02-15

    Isolated compact groups (CGs) of galaxies present a range of dynamical states, group velocity dispersions, and galaxy morphologies with which to study galaxy evolution, particularly the properties of gas both within the galaxies and in the intragroup medium. As part of a large, multiwavelength examination of CGs, we present an archival study of diffuse X-ray emission in a subset of nine Hickson compact groups (HCGs) observed with the Chandra X-Ray Observatory. We find that seven of the groups in our sample exhibit detectable diffuse emission. However, unlike large-scale emission in galaxy clusters, the diffuse features in the majority of the detected groups are linked to the individual galaxies, in the form of both plumes and halos likely as a result of vigourous star formation or activity in the galaxy nucleus, as well as in emission from tidal features. Unlike previous studies from earlier X-ray missions, HCGs 31, 42, 59, and 92 are found to be consistent with the L{sub X} -T relationship from clusters within the errors, while HCGs 16 and 31 are consistent with the cluster L{sub X} -{sigma} relation, though this is likely coincidental given that the hot gas in these two systems is largely due to star formation. We find that L{sub X} increases with decreasing group H I to dynamical-mass ratio with tentative evidence for a dependence in X-ray luminosity on H I morphology whereby systems with intragroup H I indicative of strong interactions are considerably more X-ray luminous than passively evolving groups. We also find a gap in the L{sub X} of groups as a function of the total group specific star formation rate. Our findings suggest that the hot gas in these groups is not in hydrostatic equilibrium and these systems are not low-mass analogs of rich groups or clusters, with the possible exception of HCG 62.

  19. Intragroup and Galaxy-linked Diffuse X-ray Emission In Hickson Compact Groups

    NASA Technical Reports Server (NTRS)

    Desjardins, Tyler D.; Gallagher, Sarah C.; Tzanavaris, Panayiotis; Mulchaey, John S.; Brandt, William N.; Charlton, Jane C.; Garmire, Gordon P.; Gronwall, Caryl; Cardiff, Ann; Johnson, Kelsey E.; Konstantopoulos, Iraklis, S.; Zabludoff, Ann I.

    2013-01-01

    Isolated compact groups (CGs) of galaxies present a range of dynamical states, group velocity dispersions, and galaxy morphologies with which to study galaxy evolution, particularly the properties of gas both within the galaxies and in the intragroup medium. As part of a large, multiwavelength examination of CGs, we present an archival study of diffuse X-ray emission in a subset of nine Hickson compact groups (HCGs) observed with the Chandra X-Ray Observatory. We find that seven of the groups in our sample exhibit detectable diffuse emission. However, unlike large-scale emission in galaxy clusters, the diffuse features in the majority of the detected groups are linked to the individual galaxies, in the form of both plumes and halos likely as a result of vigourous star formation or activity in the galaxy nucleus, as well as in emission from tidal features. Unlike previous studies from earlier X-ray missions, HCGs 31, 42, 59, and 92 are found to be consistent with the L(sub X-Tau) relationship from clusters within the errors, while HCGs 16 and 31 are consistent with the cluster L(sub X-sigma) relation, though this is likely coincidental given that the hot gas in these two systems is largely due to star formation. We find that L(sub X) increases with decreasing group Hi to dynamical-mass ratio with tentative evidence for a dependence in X-ray luminosity on Hi morphology whereby systems with intragroup Hi indicative of strong interactions are considerably more X-ray luminous than passively evolving groups. We also find a gap in the L(sub X) of groups as a function of the total group specific star formation rate. Our findings suggest that the hot gas in these groups is not in hydrostatic equilibrium and these systems are not low-mass analogs of rich groups or clusters, with the possible exception of HCG 62.

  20. 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

  1. 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.

  2. High-brightness table-top hard X-ray source driven by sub-100-femtosecond mid-infrared pulses

    NASA Astrophysics Data System (ADS)

    Weisshaupt, Jannick; Juvé, Vincent; Holtz, Marcel; Ku, Shinan; Woerner, Michael; Elsaesser, Thomas; Ališauskas, Skirmantas; Pugžlys, Audrius; Baltuška, Andrius

    2014-12-01

    Ultrafast structural dynamics in the condensed phase represents a key topic of current physics, chemistry and materials science. Femtosecond hard X-ray pulses are important structure probes that have been applied in time-resolved X-ray absorption and diffraction. Optical pump/X-ray probe schemes with compact laser-driven table-top sources have allowed for tiny changes of diffracted intensity to be measured with X-ray photon statistics, which has set the ultimate sensitivity limit. To address the strong quest for a higher X-ray flux, here we present the first hard X-ray plasma source driven by intense mid-infrared sub-100-fs pulses at 3.9 μm. The comparably long optical period allows for accelerating electrons from the Cu target to very high kinetic energies and for generating a characteristic Kα flux of 109 photons per pulse, 25 times more than with our 800 nm driver. Theoretical simulations account for the experimental results in a wide range of driving fields and predict a further enhancement of X-ray flux.

  3. Chandra Discovers X-ray Source at the Center of Our Galaxy

    NASA Astrophysics Data System (ADS)

    2000-01-01

    converted into the X-ray light that we see," Baganoff said. "This new result provides fresh insight that will no doubt stir heated debates on these issues "Chandra's sensitivity is 20 times better than achieved with the best previous X-ray telescopes," said Gordon Garmire, the Evan Pugh Professor of Astronomy and Astrophysics at Penn State University and head of the team that conceived and built Chandra's Advanced CCD Imaging Spectrometer (ACIS) X-ray camera, which Chandra's mirrors, make Chandra the perfect tool for studying this faint X-ray source in its crowded field." "The luminosity of the X-ray source we have discovered already is a factor of five satelllite," Baganoff said. "This poses a problem for theorists. The galactic center is a crowded place. If we were to find that most or all of the X-ray emission is not from all up." Astronomers believe that most galaxies harbor massive black holes at their centers. Many of these black holes are thought to produce powerful and brilliant point-like sources of light that astronomers call quasars and active galactic nuclei. Why the center of our galaxy is so dim is a long-standing puzzle. One Source Standing Out in a Crowd Sagittarius A*, which stands out on a radio map as a bright dot, was detected at the dynamical center of the Milky Way galaxy by radio telescopes in 1974. More recently, infrared observations of the movements of stars around Sagittarius A* has convinced most astronomers that there is a supermassive black hole at the center of our galaxy and that it is probably associated with Sagittarius A*. A black hole is an object so compact that light itself cannot escape its gravitational pull. A black hole sucks up material thrown out by normal stars around it. Because there are a million times more stars in a given volume in the galactic center than elsewhere in the galaxy, researchers cannot yet say definitively that Sagittarius A* is the newly detected source of the X-rays. "We need more data to clarify our

  4. X-ray sources in dwarf galaxies in the Virgo cluster and the nearby field

    NASA Astrophysics Data System (ADS)

    Papadopoulou, Marina; Phillipps, S.; Young, A. J.

    2016-08-01

    The extent to which dwarf galaxies represent essentially scaled down versions of giant galaxies is an important question with regards the formation and evolution of the galaxy population as a whole. Here, we address the specific question of whether dwarf galaxies behave like smaller versions of giants in terms of their X-ray properties. We discuss two samples of around 100 objects each, dwarfs in the Virgo cluster and dwarfs in a large Northern hemisphere area. We find nine dwarfs in each sample with Chandra detections. For the Virgo sample, these are in dwarf elliptical (or dwarf lenticular) galaxies and we assume that these are (mostly) low-mass X-ray binaries (LMXB) [some may be nuclear sources]. We find a detection rate entirely consistent with scaling down from massive ellipticals, viz. about one bright (i.e. LX > 1038 erg s-1) LMXB per 5 × 109 M⊙ of stars. For the field sample, we find one (known) Seyfert nucleus, in a galaxy which appears to be the lowest mass dwarf with a confirmed X-ray emitting nucleus. The other detections are in star-forming dwarf irregular or blue compact dwarf galaxies and are presumably high-mass X-ray binaries (HMXB). This time, we find a very similar detection rate to that in large late-type galaxies if we scale down by star formation rate, roughly one HMXB for a rate of 0.3 M⊙ per year. Nevertheless, there does seem to be one clear difference, in that the dwarf late-type galaxies with X-ray sources appear strongly biased to very low metallicity systems.

  5. 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.

  6. X-ray lasers - the ultimate radiation source?

    SciTech Connect

    Matthews, D.L.

    1995-12-31

    I will review the development of the x-ray laser from its first demonstration in 1984 to today`s systems which operate from 45 to 3.5 nm with output power levels up to GW and linewidths less than 10{sup -4}. At first, these sources required large pump laser facility in order to be produced, but just now new systems are appearing which are much more efficient and are near table-top in size. I will also discuss the future development of this source which should lead to wavelengths as short as 1 nm with a near-diffraction-limited output characteristics and considerable average output power, up to 10{sup 15} ph/sec. Finally, I will discuss some of the interesting applications such as in vitro biological imaging, microsurgery on microorganisms, construction of nanomachines, probing of semiconductors and plasmas, lithographic printing of semiconductor circuits and numerous other potential uses.

  7. 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

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

    DOE PAGES

    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

  9. Geometry of X-ray sources in accreting black-hole binaries

    NASA Astrophysics Data System (ADS)

    Zdziarski, Andrzej

    2016-07-01

    The structure of the X-ray sources in the hard spectral state of accreting black-hole binaries has been a subject of intense debate. The paradigm dominant for many years postulated that the accretion disc in the hard state is truncated at some radius >> the innermost stable orbit (ISCO) whereas the disc reaches the ISCO in the soft state. This paradigm explains a large body of observed phenomena, including the spectral and variability differences between the states and outbursts of transient sources, proceeding from quiescence (where no disc is present) through the hard state to the peak flux in the soft state. On the other hand, there have been numerous claims in recent years that the disc extends to the ISCO in the hard state. Also, the primary X-ray source has been postulated to consist of a compact source on-axis of the rotating black hole (a lamppost). Those claims are based on observations of broad Fe K lines and of soft X-ray components interpreted as blackbody-emitting accretion discs. I will discuss arguments for and against the disc truncation and the lamppost geometry based on current spectral and timing results.

  10. Inductive Voltage Adder Driven X-Ray Sources for Hydrodynamic Radiography

    SciTech Connect

    Bailey, V.; Cordova, S.; Droemer, D.; Gustwiller, J.; Hunt, E.; Johnson, D.L.; MacLeod, G.; Maenchen, John; Menge, P.; Molina, I.; Oliver, B; Olson, C.; Rosenthal, S; Rovang, D.; Smith, I.; Welch, D.; Woo, L.

    1999-06-17

    Inductive Voltage Adder (IVA) accelerators were developed to provide high-current (100s of kA) power pulses at high voltage (up to 20 MV) using robust modular components. This architecture simultaneously resolves problems found in conventional pulsed and linear induction accelerators. A variety of high-brightness pulsed x-ray radiographic sources are needed from sub-megavolt to 16-MeV endpoints with greater source brightness (dose/spot) than presently available. We are applying IVA systems to produce very intense (up to 75 TW/cm{sup 2}) electron beams for these flash radiographic applications. The accelerator electromagnetic pulse is converted to a directed electron beam at the end of a self-magnetically insulated vacuum transmission line. The cantilevered cathode threading the accelerator cavities terminates in a small (1-mm diameter) needle, producing the electron beam which is transported to a grounded bremsstrahlung converter within a strong ({approximately}50-T) axial magnetic field. These systems produce mm-sized stable electron beams, yielding very intense x-ray sources. Detailed simulations of the electron beam generation, transport, and target interaction are presented along with scaling laws for the radiation production and x-ray spot size. Experimental studies confirm these simulations and show this reliable, compact, and inexpensive technology scales to 1000-R doses a meter from a mm-diameter source in 50 ns.

  11. 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.

  12. 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.

  13. The X-ray Correlation Spectroscopy instrument at the Linac Coherent Light Source

    NASA Astrophysics Data System (ADS)

    Robert, A.; Curtis, R.; Flath, D.; Gray, A.; Sikorski, M.; Song, S.; Srinivasan, V.; Stefanescu, D.

    2013-03-01

    The X-ray Correlation Spectroscopy instrument (XCS) at the Linac Coherent Light Source (LCLS) is a dedicated instrument using coherent x-ray scattering techniques to investigate dynamics in condensed matter systems. XCS can probe both slow and ultrafast dynamics on lengthscales of interest. It employs an extensive suite of X-ray instrumentation to tailor the LCLS X-ray beam properties to experimental requirements. Results demonstrating the full transverse coherence of the LCLS beam are presented.

  14. 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

  15. Constraining compactness and magnetic field geometry of X-ray pulsars using pulse profile statistics

    SciTech Connect

    Annala, Marja; Poutanen, Juri

    2010-07-15

    We use the statistics of 131 X-ray pulsar light curves in order to constrain the neutron star compactness and the inclination of the magnetic dipole. The X-ray pulse profiles are classified according to the number of pulses seen during one period, dividing them into two classes, single- and double-peaked. The relative fraction of pulsars in these classes is compared with the probabilities predicted by a theoretical model for different types of pencil-beam patterns. Our results show that a statistic of pulse profiles does not constrain compactness of the neutron stars. In contrast to the previous claim, the data do not require the magnetic inclination to be confined in a narrow interval but instead the magnetic dipole can have arbitrary inclinations to the rotational axis. The observed fractions of different types of light curves can be explained by taking into account the X-ray detector sensitivity (i.e. detection threshold for weak pulses), which decreases the fraction of the observed double-peaked light curves.

  16. 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.

  17. Accretion states of ultraluminous X-ray sources

    NASA Astrophysics Data System (ADS)

    Soria, Roberto; Swartz, Doug

    2009-09-01

    Ultraluminous X-ray sources (ULXs) have extended our knowledge of accretion onto black holes, and in particular of their different ``states'' as a function of accretion rate. At moderate luminosities (˜ 1E39-1E40 erg/s), the X-ray spectra of most ULXs are either fitted by non-standard accretion disks (eg, slim disks) or by a power-law, consistent with inverse-Compton emission (probably an extension of the ``steep-power-law'' state of Galactic black holes). At the highest luminosities (>˜ 1E40 erg/s), most ULXs have a power-law dominated spectrum; in particular, about half of them have hard photon indices (high/hard state, Gamma <˜ 1.7). In addition, two more elements are often found: a thermal ``soft excess'' is the signature of the standard thin disk at large radii, which constrains the radial size of the inner Comptonizing/outflow region; and a break or downturn of the power-law at ˜ 5 keV provides a characteristic temperature of the electrons in the inner region. Thus, the physics of super-Eddington accretion states correlates with that of the low states, with different systems dominated either by energy advection, or mechanical output, or Comptonizing coronae. Another intriguing issue we will discuss is whether there is a cutoff in the luminosity distribution at ˜ a few E40 erg/s, which would still be consistent with stellar black holes formed from direct collapse in metal-poor environments (maximum mass ˜ 70 Msun). If the power-law distribution extends to higher luminosities, it requires more massive black holes, perhaps formed from mergers in dense stellar/protostellar cluster environments

  18. 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.

  19. Compact Objects In Binary Systems: Formation and Evolution of X-ray Binaries and Tides in Double White Dwarfs

    NASA Astrophysics Data System (ADS)

    Valsecchi, Francesca

    Binary star systems hosting black holes, neutron stars, and white dwarfs are unique laboratories for investigating both extreme physical conditions, and stellar and binary evolution. Black holes and neutron stars are observed in X-ray binaries, where mass accretion from a stellar companion renders them X-ray bright. Although instruments like Chandra have revolutionized the field of X-ray binaries, our theoretical understanding of their origin and formation lags behind. Progress can be made by unravelling the evolutionary history of observed systems. As part of my thesis work, I have developed an analysis method that uses detailed stellar models and all the observational constraints of a system to reconstruct its evolutionary path. This analysis models the orbital evolution from compact-object formation to the present time, the binary orbital dynamics due to explosive mass loss and a possible kick at core collapse, and the evolution from the progenitor's Zero Age Main Sequence to compact-object formation. This method led to a theoretical model for M33 X-7, one of the most massive X-ray binaries known and originally marked as an evolutionary challenge. Compact objects are also expected gravitational wave (GW) sources. In particular, double white dwarfs are both guaranteed GW sources and observed electromagnetically. Although known systems show evidence of tidal deformation and a successful GW astronomy requires realistic models of the sources, detached double white dwarfs are generally approximated to point masses. For the first time, I used realistic models to study tidally-driven periastron precession in eccentric binaries. I demonstrated that its imprint on the GW signal yields constrains on the components' masses and that the source would be misclassified if tides are neglected. Beyond this adiabatic precession, tidal dissipation creates a sink of orbital angular momentum. Its efficiency is strongest when tides are dynamic and excite the components' free

  20. 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.

  1. 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.

  2. A setup for resonant inelastic soft x-ray scattering on liquids at free electron laser light sources

    SciTech Connect

    Kunnus, Kristjan; Schreck, Simon; Foehlisch, Alexander; Eckert, Sebastian; Beye, Martin; Suljoti, Edlira; Weniger, Christian; Wernet, Philippe; Kalus, Christian; Nordlund, Dennis; Zhang, Wenkai; Hartsock, Robert W.; Gaffney, Kelly J.; Schlotter, William F.; Turner, Joshua J.; Kennedy, Brian; and others

    2012-12-15

    We present a flexible and compact experimental setup that combines an in vacuum liquid jet with an x-ray emission spectrometer to enable static and femtosecond time-resolved resonant inelastic soft x-ray scattering (RIXS) measurements from liquids at free electron laser (FEL) light sources. We demonstrate the feasibility of this type of experiments with the measurements performed at the Linac Coherent Light Source FEL facility. At the FEL we observed changes in the RIXS spectra at high peak fluences which currently sets a limit to maximum attainable count rate at FELs. The setup presented here opens up new possibilities to study the structure and dynamics in liquids.

  3. 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.

  4. King's College laser plasma x-ray source design

    NASA Astrophysics Data System (ADS)

    Alnaimi, Radhwan; Adjei, Daniel; Alatabi, Saleh; Appuhamilage, Indika Arachchi; Michette, Alan

    2013-05-01

    The aim of this work is to design and build a source for a range of applications, with optimized multilayer structures in order to use the source output as efficiently as possible. The source is built around a Nd:YAG laser with fundamental wavelength 1064 nm, frequency doubled 532 nm (green) and tripled 355 nm, with a pulse length of about 800 ps and a repetition rate up to 50 Hz. The target material is Mylar (C10H8O4) tape, which is cheap, readily available and has many benefits as explained in this article. A versatile cubic target chamber and a set of computer controlled stage motors are used to allow positioning of the X-ray emission point. A range of measures is used to protect delicate components and optics, including a glass slide between the focusing lens and the target to prevent the lens being coated with debris. A low pressure gas (typically 3-6 mbar) is used inside the chamber as collision of atomic size debris particles with gas molecules reduces their kinetic energy and consequently their adhesion to the surrounding surfaces. The gas used is typically helium or nitrogen, the latter also acting as a spectral filter. Finally, the chamber is continually pumped to ensure that more than 70% of the debris particles are pumped out of the chamber.

  5. Theoretical considerations for X-ray phase contrast mammography by Thomson source

    NASA Astrophysics Data System (ADS)

    Cedola, A.; Bukreeva, I.; Lagomarsino, S.; Petrillo, V.; Maroli, C.

    2009-09-01

    The advent, in the near future, of compact X-ray sources like Thomson Back-Scattering (TBS) will allow the clinical application of advanced X-ray imaging techniques, such as phase contrast, with higher sensitivity and lower impact in terms of dose delivery. In this work, we theoretically investigated the possibility of using such sources for phase contrast imaging of micro-calcifications included in a breast tissue. In our study we analyzed the phase and amplitude distribution of the TBS source and we showed that this source can be used for phase contrast imaging since the source coherence at the sample position is sufficiently high for achieving good contrast and micrometer spatial resolution. Indeed the spatial coherence of a TBS source is closer to that of a synchrotron radiation source, and much better than that of a laboratory source. Moreover, we showed the advantages of phase imaging with respect to standard absorption imaging, in the specific case of micro-calcifications detection.

  6. A proposal for a collecting mirror assembly for large divergence x-ray sources.

    PubMed

    Ichimaru, Satoshi; Hatayama, Masatoshi; Ohchi, Tadayuki; Oku, Satoshi

    2014-11-01

    We propose a new type of collecting mirror assembly (CMA) for x rays, which will enable us to build a powerful optical system for collecting x rays from large divergence sources. The CMA consists of several mirror sections connected in series. The angle of each section is designed so that the x rays reflected from it are parallel to the x rays directly incident on the following sections. A simplified CMA structure is designed and applied to the Al-Kα emission line. It is estimated that by using the CMA the number of x rays detected could be increased by a factor of about 2.5.

  7. 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.

  8. A compact high-resolution X-ray ion mobility spectrometer.

    PubMed

    Reinecke, T; Kirk, A T; Heptner, A; Niebuhr, D; Böttger, S; Zimmermann, S

    2016-05-01

    For the ionization of gaseous samples, most ion mobility spectrometers employ radioactive ionization sources, e.g., containing (63)Ni or (3)H. Besides legal restrictions, radioactive materials have the disadvantage of a constant radiation with predetermined intensity. In this work, we replaced the (3)H source of our previously described high-resolution ion mobility spectrometer with 75 mm drift tube length with a commercially available X-ray source. It is shown that the current configuration maintains the resolving power of R = 100 which was reported for the original setup containing a (3)H source. The main advantage of an X-ray source is that the intensity of the radiation can be adjusted by varying its operating parameters, i.e., filament current and acceleration voltage. At the expense of reduced resolving power, the sensitivity of the setup can be increased by increasing the activity of the source. Therefore, the performance of the setup can be adjusted to the specific requirements of any application. To investigate the relation between operating parameters of the X-Ray source and the performance of the ion mobility spectrometer, parametric studies of filament current and acceleration voltage are performed and the influence on resolving power, peak height, and noise is analyzed.

  9. Conceptual Design of Dielectric Accelerating Structures for Intense Neutron and Monochromatic X-ray Sources

    SciTech Connect

    Blanovsky, Anatoly

    2004-12-07

    Bright compact photon sources, which utilize electron beam interaction with periodic structures, may benefit a broad range of medical, industrial and scientific applications. A class of dielectric-loaded periodic structures for hard and soft X-ray production has been proposed that would provide a high accelerating gradient when excited by an external RF and/or primary electron beam. Target-distributed accelerators (TDA), in which an additional electric field compensates for lost beam energy in internal targets, have been shown to provide the necessary means to drive a high flux subcritical reactor (HFSR) for nuclear waste transmutation. The TDA may also be suitable for positron and nuclear isomer production, X-ray lithography and monochromatic computer tomography. One of the early assumptions of the theory of dielectric wake-field acceleration was that, in electrodynamics, the vector potential was proportional to the scalar potential. The analysis takes into consideration a wide range of TDA design aspects including the wave model of observed phenomena, a layered compound separated by a Van der Waals gap and a compact energy source based on fission electric cells (FEC) with a multistage collector. The FEC is a high-voltage power source that directly converts the kinetic energy of the fission fragments into electrical potential of about 2MV.

  10. On the x-ray emission from the radio source SGR A*

    SciTech Connect

    Coker, R. F.; Pittard, J. M.

    2004-01-01

    Recent infrared observations of the Galactic Center have permitted the estimation of orbital parameters for the 8 O stars closest to the compact, nonthermal radio source, Sgr A*. The emission of Sgr A* is thought to be due to the accretion of gas down the potential well of a {approx} 3 x 10{sup 6} solar mass black hole at the dynamical heart of the Milky Way. The O stars are located within 0.03 pc of Sgr A* and are likely to have significant stellar winds. Since they are deep within the potential well of a black hole, much of their winds are gravitationally bound. These hot winds may be piling up and emitting significantly in the X-rays. Thus it is possible that the emission from the recently detected compact CHANDRA source may at least in part be due to the winds of these O stars rather than the hot gas close to the event horizon of the black hole. This has serious implications for applicable black hole accretion models. From preliminary 3D numerical simulations which treat the 8 O stars as mass sources moving on individual orbits, we have constructed simulated X-ray images. We present these images and discuss their impact on accretion models for Sgr A*.

  11. Revealing the Nature of the Ultraluminous X-ray sources in NGC 4861

    NASA Astrophysics Data System (ADS)

    Yang, Yi-Jung

    2012-09-01

    ULXs are defined as off-nuclear X-ray sources with isotropic luminosities much higher than the Eddington limit for a solar mass black hole (Lx~1.3e38 erg/s). Typical X-ray luminosities of ULXs are in between 10^39 and 10^41 erg/s. The physical nature of ULXs has been an enigma because of their high energy output. Some ULXs show strong variability suggesting that they are accreting compact objects. Assuming the emission is isotropic, some of the very bright ULXs may harbor intermediate-mass black holes. Some ULXs may just be stellar mass black holes with radiation pressure-dominated or slim accretion disks that cause super-Eddington luminosities. Alternatively, some ULXs may be young X-ray luminous supernova remnants in a high density medium, or hypernova remnants. Optical counterparts of some ULXs are found to be consistent with high mass stars with sometimes evidence for variability and blue spectra possibly indicative of an accretion disc. In addition, a large fraction of ULXs appear to be associated with extended nebulae; supershells hundreds of parsecs in diameter. These large supershells are found to be powered by photoionization and/ or shock-excitation from the ULXs. In this talk, I will present our new results of ULXs in the metal-deficit blue compact dwarf galaxy NGC 4861. Previous studies reveal two ULXs (both ~10^40 erg/s) in this galaxy. From our INT H-alpha and [SII] images, we find that both sources are in the proximity of regions of diffuse nebulosity, which may be powered by the ULXs. Moreover, ULX-1 is found to be associated with a bright H-alpha point source with a [SII] counterpart. Our new Chandra observation together with several archival HST images confirm the association, which will shed light on understanding the nature of these objects.

  12. 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.

  13. 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

  14. Acceleration of binary X-ray sources by their radiation

    NASA Astrophysics Data System (ADS)

    Pal'Shin, V. D.; Tsygan, A. I.

    1998-03-01

    We consider a case where the magnetic field of a neutron star in an X-ray binary system differs from a dipole field. This difference gives rise to an asymmetry in the X-ray radiation from the system and, consequently, to an accelerating force. After averaging over the rotation period of the neutron star, the component of the force along its spin axis remains. Its magnitude, F = Xi L_X/c (where L_X is the total X-ray luminosity of the neutron star, and Xi is the radiation asymmetry coefficient), can exceed the force of gravitational attraction of the binary system to the Galaxy. This effect is most important for low-mass X-ray binary systems at the stage of intense accretion of matter onto the neutron stars. Such systems form the Galactic halo, while some of them go away into intergalactic space.

  15. Spectroscopic follow-up of NIR candidate counterparts to Galactic Center X-ray sources

    NASA Astrophysics Data System (ADS)

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

    2010-08-01

    The Chandra X-ray Observatory has discovered 4339 X-ray point sources within the 17 arcmin^2 field centered on Sgr A^*. Nearly a dozen of the brighter near-IR (NIR) counterparts in this region have been spectroscopically identified as Wolf-Rayet/O supergiants, possibly in colliding wind binaries or high mass X-ray binaries. However, the nature of the X-ray sources whose candidate counterparts have IR magnitudes of K_s > 12 mag is almost completely unknown. We utilized our JHK ISPI imaging of this 17 arcmin^2 region to create a catalog of NIR/X-ray astrometric matches with 2205 X-ray/IR sources. Using Monte-Carlo simulations, we identified 88 IR sources that have a high probability of being true counterparts to Galactic Center (GC) X-ray sources. We propose to obtain JHK spectra of 28 potential IR counterparts with K_s=12-14 mag. Our analysis suggests that half of these objects will be true physical counterparts. Definitive identification of the X-ray source counterparts will help probe a previously unknown segment of the GC X-ray source population, and will have important implications for our understanding of XRBs in the Galaxy, including their formation, evolutionary history, and physical characteristics.

  16. 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.

  17. The associated X-ray spectra of Amersham caesium-137 afterloading sources.

    PubMed

    Bradley, D A; Chong, C S

    1987-02-01

    Low-energy X rays are clearly observed in the energy spectra of Amersham 137Cs afterloading sources. Examination is made of the effects of encapsulation and source train attenuation on the source spectra. Estimates of the resulting X-ray intensities are also made.

  18. 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.

  19. 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.

  20. 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.

  1. Optical identification of X-ray source 1RXS J180431.1-273932 as a magnetic cataclysmic variable

    NASA Astrophysics Data System (ADS)

    Masetti, N.; Nucita, A. A.; Parisi, P.

    2012-08-01

    The X-ray source 1RXS J180431.1-273932 has been proposed as a new member of the symbiotic X-ray binary (SyXB) class of systems, which are composed of a late-type giant that loses matter to an extremely compact object, most likely a neutron star. In this paper, we present an optical campaign of imaging plus spectroscopy on selected candidate counterparts of this object. We also reanalyzed the available archival X-ray data collected with XMM-Newton. We find that the brightest optical source inside the 90% X-ray positional error circle is spectroscopically identified as a magnetic cataclysmic variable (CV), most likely of intermediate polar type, through the detection of prominent Balmer, He i, He ii, and Bowen blend emissions. On either spectroscopic or statistical grounds, we discard as counterparts of the X-ray source the other optical objects in the XMM-Newton error circle. A red giant star of spectral type M5 III is found lying just outside the X-ray position: we consider this latter object as a fore-/background one and likewise rule it out as a counterpart of 1RXS J180431.1-273932. The description of the X-ray spectrum of the source using a bremsstrahlung plus black-body model gives temperatures of kTbr ~ 40 keV and kTbb ~ 0.1 keV for these two components. We estimate a distance of d ~ 450 pc and a 0.2-10 keV X-ray luminosity of LX ~ 1.7 × 1032 erg s-1 for this system and, using the information obtained from the X-ray spectral analysis, a mass MWD ~ 0.8 M⊙ for the accreting white dwarf (WD). We also confirm an X-ray periodicity of 494 s for this source, which we interpret as the spin period of the WD. In summary, 1RXS J180431.1-273932 is identified as a magnetic CV and its SyXB nature is excluded. Partly based on observations collected at the Italian Telescopio Nazionale Galileo, located at the Observatorio del Roque de los Muchachos (Canary Islands, Spain).Reduced data used for imaging and spectra is only available at the CDS via anonymous ftp to cdsarc

  2. 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.

  3. 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.

  4. Phase-contrast imaging with a novel X-ray source

    SciTech Connect

    Takahashi, Yumiko; Kuwada, Takao; Sakai, Takeshi; Hayakawa, Yasushi; Nakao, Keisuke; Nogami, Kyoko; Imagaki, Manabu; Tanaka, Toshinari; Hayakawa, Ken; Sato, Isamu

    2010-04-06

    A novel X-ray source based on Parametric X-ray radiation (PXR) has been employed for phase-contrast imaging at the Laboratory for Electron Beam Research and Application (LEBRA), Nihon University, Japan. The PXR X-rays were generated by the 100 MeV electron beam passing through a Si single crystal. The X-rays in the 16approx34 keV range were chosen for imaging of biological samples. The quasi-monochromatic, tunable, and coherent X-ray source is appropriate for this application. In addition, the large X-ray beam irradiation field of approximately 100 mm in diameter, which was achieved without special optics, suggests that the PXR is applicable to imaging for medical diagnostics.

  5. A soft X-ray spectrometer for diffuse cosmic sources

    NASA Technical Reports Server (NTRS)

    Borken, R. J.; Kraushaar, W. L.

    1976-01-01

    The design of a Bragg crystal spectrometer for the diffuse soft X-ray background is described. The instrument has no moving parts; a 6 degree x 20 degree FWHM field of view; resolution in the range 20-100; and spans wavelength ranges 44-80 A or 13-23 A when lead stearate or KAP crystals are used. If placed on a small spacecraft, integration times of approximately 1000 s will be required to detect the existence of the stronger lines expected in the X-ray background.

  6. Relativistic klystron driven compact high gradient accelerator as an injector to an X-ray synchrotron radiation ring

    DOEpatents

    Yu, David U. L.

    1990-01-01

    A compact high gradient accelerator driven by a relativistic klystron is utilized to inject high energy electrons into an X-ray synchrotron radiation ring. The high gradients provided by the relativistic klystron enables accelerator structure to be much shorter (typically 3 meters) than conventional injectors. This in turn enables manufacturers which utilize high energy, high intensity X-rays to produce various devices, such as computer chips, to do so on a cost effective basis.

  7. 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.

  8. OPTICAL STUDY OF THE HYPER-LUMINOUS X-RAY SOURCE 2XMM J011942.7+032421

    SciTech Connect

    Gutiérrez, Carlos M.; Moon, Dae-Sik

    2014-12-10

    We present the identification and characterization of the optical counterpart to 2XMM J011942.7+032421, one of the most luminous and distant ultra-luminous X-ray sources (ULXs). The counterpart is located near a star-forming region in a spiral arm of the galaxy NGC 470 with u, g, and r magnitudes of 21.53, 21.69, and 21.71 mag, respectively. The luminosity of the counterpart is much larger than that of a single O-type star, indicating that it may be a stellar cluster. Our optical spectroscopic observations confirm the association of the X-ray source and the optical counterpart with its host galaxy NGC 470, which validates the high, ≳10{sup 41} erg s{sup -1}, X-ray luminosity of the source. Its optical spectrum is embedded with numerous emission lines, including H recombination lines, metallic forbidden lines, and more notably the high-ionization He II (λ4686) line. That line shows a large velocity dispersion of ≅410 km s{sup -1}, consistent with the existence of a compact (<5 AU) highly ionized accretion disk rotating around the central X-ray source. The ∼1.4 × 10{sup 37} erg s{sup -1} luminosity of the He II line emission makes the source one of the most luminous ULXs in that emission. This, together with the high X-ray luminosity and the large velocity dispersion of the He II emission, suggests that the source is an ideal candidate for more extensive follow-up observations for understanding the nature of hyper-luminous X-ray sources, a more luminous subgroup of ULXs, and more likely candidates for intermediate-mass black holes.

  9. 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.

  10. 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.

  11. 1RXS J180408.9-342058: An ultra compact X-ray binary candidate with a transient jet

    NASA Astrophysics Data System (ADS)

    Baglio, M. C.; D'Avanzo, P.; Campana, S.; Goldoni, P.; Masetti, N.; Muñoz-Darias, T.; Patiño-Álvarez, V.; Chavushyan, V.

    2016-03-01

    Aims: We present a detailed near-infrared/optical/UV study of the transient low-mass X-ray binary 1RXS J180408.9-342058 performed during its 2015 outburst, which is aimed at determining the nature of its companion star. Methods: We obtained three optical spectra (R ~ 1000) at the 2.1 m San Pedro Mártir Observatory telescope (México). We performed optical and NIR photometric observations with both the REM telescope and the New Technology Telescope (NTT) in La Silla. We obtained optical and UV observations from the Swift archive. Finally, we performed optical polarimetry of the source using the EFOSC2 instrument mounted on the NTT. Results: The optical spectrum of the source is almost featureless since the hydrogen and He I emissions lines, typically observed in LMXBs, are not detected. Similarly, carbon and oxygen lines are not observed either. We marginally detect the He II 4686 Å emission line, suggesting the presence of helium in the accretion disc. No significant optical polarisation level was observed. Conclusions: The lack of hydrogen and He I emission lines in the spectrum implies that the companion is likely not a main-sequence star. Driven by the tentative detection of the He II 4686 Å emission line, we suggest that the system could harbour a helium white dwarf. If this is the case, 1RXS J180408.9-342058 would be an ultra-compact X-ray binary. By combining an estimate of the mass accretion rate together with evolutionary tracks for a He white dwarf, we obtain a tentative orbital period of ~40 min. We also built the NIR-optical-UV spectral energy distribution (SED) of the source at two different epochs. One SED was gathered when the source was in the soft X-ray state and this SED is consistent with the presence of a single thermal component. The second SED, obtained when the source was in the hard X-ray state, shows a thermal component along with a tail in the NIR, which likely indicates the presence of a (transient) jet. Based on observations made with

  12. 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.

  13. 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…

  14. Compact monochromatic flash x-ray generator utilizing a disk-cathode molybdenum tube.

    PubMed

    Sato, Eiichi; Tanaka, Etsuro; Mori, Hidezo; Kawai, Toshiaki; Ichimaru, Toshio; Sato, Shigehiro; Takayama, Kazuyoshi; Ido, Hideaki

    2005-01-01

    The high-voltage condensers in a polarity-inversion two-stage Marx surge generator are charged from -50 to -70 kV by a power supply, and the electric charges in the condensers are discharged to an x-ray tube after closing gap switches in the surge generator with a trigger device. The x-ray tube is a demountable diode, and the turbo molecular pump evacuates air from the tube with a pressure of approximately 1 mPa. Clean molybdenum Kalpha lines are produced using a 20 microm-thick zirconium filter, since the tube utilizes a disk cathode and a rod target, and bremsstrahlung rays are not emitted in the opposite direction to that of electron acceleration. At a charging voltage of -70 kV, the instantaneous tube voltage and current were 120 kV and 1.0 kA, respectively. The x-ray pulse widths were approximately 70 ns, and the generator produced instantaneous number of Kalpha photons was approximately 3 x 10(7) photons/cm2 per pulse at 0.5 m from the source of 3.0 mm in diameter.

  15. Compact monochromatic flash x-ray generator utilizing a disk-cathode molybdenum tube

    SciTech Connect

    Sato, Eiichi; Tanaka, Etsuro; Mori, Hidezo; Kawai, Toshiaki; Ichimaru, Toshio; Sato, Shigehiro; Takayama, Kazuyoshi; Ido, Hideaki

    2005-01-01

    The high-voltage condensers in a polarity-inversion two-stage Marx surge generator are charged from -50 to -70 kV by a power supply, and the electric charges in the condensers are discharged to an x-ray tube after closing gap switches in the surge generator with a trigger device. The x-ray tube is a demountable diode, and the turbo molecular pump evacuates air from the tube with a pressure of approximately 1 mPa. Clean molybdenum K{alpha} lines are produced using a 20 {mu}m-thick zirconium filter, since the tube utilizes a disk cathode and a rod target, and bremsstrahlung rays are not emitted in the opposite direction to that of electron acceleration. At a charging voltage of -70 kV, the instantaneous tube voltage and current were 120 kV and 1.0 kA, respectively. The x-ray pulse widths were approximately 70 ns, and the generator produced instantaneous number of K{alpha} photons was approximately 3x10{sup 7} photons/cm{sup 2} per pulse at 0.5 m from the source of 3.0 mm in diameter.

  16. 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.

  17. 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.

  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. 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.

  20. Development of a multilayer mirror for high-intensity monochromatic x-ray using lab-based x-ray source.

    PubMed

    Nguyen, Thanh-hai; Song, Seonggeun; Jung, Jin-Ho; Jeon, Insu

    2012-09-15

    A parabolic, multilayer x-ray mirror, which can be used with a general lab-based x-ray source, was designed and fabricated. A glass substrate for the mirror was fabricated. Its surface was determined by following the rotation of a parabolic curve and was polished precisely. On the substrate surface, six W/Al bilayers were deposited to form the multilayer mirror. The effects of the mirror on x-ray images were investigated based on the calculated modulation transfer function (MTF) and image intensity values. Higher MTF and intensity values of an x-ray image were obtained using the mirror.

  1. Bending magnet source: A radiation source for X-ray phase contrast tomography

    NASA Astrophysics Data System (ADS)

    Dhal, B. B.; Peele, A. G.; McMahon, P. J.; De Carlo, F.; Nugent, K. A.

    2006-11-01

    The rapid development of electronic data processing and phase retrieval technique for image reconstruction leads to new opportunities in X-ray phase tomography. A range of radiographic and tomographic demonstrations have now been made, typically utilizing the coherent flux from an insertion device at a synchrotron or a micro-focus laboratory source. In this paper we demonstrate that useful results may be obtained using a bending magnet source at a synchrotron. In particular we show that the same beamline can be used to make and characterize a sample made by X-ray lithographic methods.

  2. ComIXS on BACH: a compact soft x-ray spectrometer operating at Elettra

    SciTech Connect

    Cocco, Daniele; Matteucci, Maurizio; Zangrando, Marco; Bondino, Federica; Zacchigna, Michele; Plate, Mauro; Parmigiani, Fulvio; Nelles, Bruno; Prince, Kevin C.

    2004-05-12

    To accommodate increasing interest in soft x-ray inelastic scattering, a new spectrometer has been designed, constructed and commissioned at Elettra. This instrument uses as the dispersive element one of two interchangeable Variable Line Spacing (VLS) spherical gratings. The energy scan is performed by a 7 cm linear translation of a back illuminated CCD which also collects the zero order light, facilitating alignment and calibration. The two gratings have the same radius of curvature while the groove densities and the groove density variations differ by a factor four. Thus the energies focused by the gratings at a particular position differ by a factor of four. The total length of the instrument is 60 cm, the energy range covered is roughly 25-1000 eV and the expected resolving power ranges from 1000 to 5000. The spectrometer is now operating on the beamline Bach. It takes advantage of the small size of the photon spot in the experimental chamber and of the possibility to control the polarization of the incoming radiation. The small spot constitutes the virtual entrance slit, and the spectrometer collects the photons emitted in a solid angle of about 30x10 mrad2. The instrument, named ComIXS (Compact Inelastic X-ray Spectrometer), has been routinely operating since October 2002. Several experiments have already been carried out, and some results illustrating the characteristics of the instrument are described. The manufacture and testing of the blaze gratings are also discussed.

  3. ComIXS on BACH: a compact soft x-ray spectrometer operating at Elettra

    NASA Astrophysics Data System (ADS)

    Cocco, Daniele; Zangrando, Marco; Matteucci, Maurizio; Bondino, Federica; Platè, Mauro; Zacchigna, Michele; Parmigiani, Fulvio; Nelles, Bruno; Prince, Kevin C.

    2004-05-01

    To accommodate increasing interest in soft x-ray inelastic scattering, a new spectrometer has been designed, constructed and commissioned at Elettra. This instrument uses as the dispersive element one of two interchangeable Variable Line Spacing (VLS) spherical gratings. The energy scan is performed by a 7 cm linear translation of a back illuminated CCD which also collects the zero order light, facilitating alignment and calibration. The two gratings have the same radius of curvature while the groove densities and the groove density variations differ by a factor four. Thus the energies focused by the gratings at a particular position differ by a factor of four. The total length of the instrument is 60 cm, the energy range covered is roughly 25-1000 eV and the expected resolving power ranges from 1000 to 5000. The spectrometer is now operating on the beamline Bach. It takes advantage of the small size of the photon spot in the experimental chamber and of the possibility to control the polarization of the incoming radiation. The small spot constitutes the virtual entrance slit, and the spectrometer collects the photons emitted in a solid angle of about 30×10 mrad2. The instrument, named ComIXS (Compact Inelastic X-ray Spectrometer), has been routinely operating since October 2002. Several experiments have already been carried out, and some results illustrating the characteristics of the instrument are described. The manufacture and testing of the blaze gratings are also discussed.

  4. Six dimensional X-ray Tensor Tomography with a compact laboratory setup

    NASA Astrophysics Data System (ADS)

    Sharma, Y.; Wieczorek, M.; Schaff, F.; Seyyedi, S.; Prade, F.; Pfeiffer, F.; Lasser, T.

    2016-09-01

    Attenuation based X-ray micro computed tomography (XCT) provides three-dimensional images with micrometer resolution. However, there is a trade-off between the smallest size of the structures that can be resolved and the measurable sample size. In this letter, we present an imaging method using a compact laboratory setup that reveals information about micrometer-sized structures within samples that are several orders of magnitudes larger. We combine the anisotropic dark-field signal obtained in a grating interferometer and advanced tomographic reconstruction methods to reconstruct a six dimensional scattering tensor at every spatial location in three dimensions. The scattering tensor, thus obtained, encodes information about the orientation of micron-sized structures such as fibres in composite materials or dentinal tubules in human teeth. The sparse acquisition schemes presented in this letter enable the measurement of the full scattering tensor at every spatial location and can be easily incorporated in a practical, commercially feasible laboratory setup using conventional X-ray tubes, thus allowing for widespread industrial applications.

  5. On the Nature of the Compact Object in SS 433. Observational Evidence of X-Ray Photon Index Saturation

    NASA Technical Reports Server (NTRS)

    Seifina, Elena; Titarchuk, Lev

    2010-01-01

    We present an analysis of the X-ray spectral properties observed from black hole , candidate (BHC) binary SS 433. We have analyzed Rossi X-ray Time Explorer (RXTE) data from this source, coordinated with Green Bank Interferometer/RATAN-600. We show that SS 433 undergoes a X-ray spectral transition from the low hard state (LHS) to the intermediate state (IS). We show that the X-ray broad-band energy spectra during all spectral states are well fit by a sum of so called "Bulk Motion Comptonization (BMC) component" and by two (broad and narrow) Gaussians for the continuum and line emissions respectively. In addition to these spectral model components we also find a strong feature that we identify as a" blackbody-like (BB)" component which color temperature is in the range of 4-5 keV in 24 IS spectra during the radio outburst decay in SS 433. Our observational results on the "high temperature BB" bump leads us to suggest the presence of gravitationally redshifted annihilation line emission in this source. In fact this spectral feature has been recently reproduced in Monte Carlo simulations by Laurent and Titarchuk. We have also established the photon index saturation at about 2.3 in index vs mass accretion correlation. This index-mass accretion correlation allows us to evaluate the low limit of black hole (BH) mass of compact object in SS 433, M(sub bh) approximately > 2 solar masses, using the scaling method using BHC GX 339-4 as a reference source. Our estimate of the BH mass in SS 433 is consistent with recent BH mass measurement using the radial-velocity measurements of the binary system by Hillwig & Gies who find that M(sub x)( = (4.3 +/- 0.8) solar masses. This is the smallest BH mass found up to now among all BH sources. Moreover, the index saturation effect versus mass accretion rate revealed in SS 433, like in a number of other BH candidates, is the strong observational evidence for the presence of a BH in SS 433.

  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. 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 addition

  8. 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

  9. High Power Experiment of X-Band Thermionic Cathode RF Gun for Compton Scattering X-ray Source

    SciTech Connect

    Sakamoto, Fumito; Uesaka, Mitsuru; Dobashi, Katsuhiro; Yamamoto, Tomohiko; Meng, De; Urakawa, Junji; Higo, Toshiyasu; Akemoto, Mitsuo; Matsuo, Kenichi; Sakae, Hisaharu; Yamamoto, Masashi

    2006-11-27

    We are currently developing a compact monochromatic X-ray source based on laser-electron collision. To realize remarkably compact-, high-intensity- and highly-stable-system, we adopt an X-band multi-bunch liner accelerator (linac) and reliable Q-switch laser. The X-ray yields by the multi-bunch electron beam and Q-switch Nd: YAG laser of 1.4 J/10 ns (FWHM) (532 nm, second harmonic) is 107 photons/RF-pulse (108 photons/sec for 10 Hz operation). The injector of the system consists of a 3.5-cell X-band thermionic cathode RF gun and an alpha magnet. So far we have achieved beam generation from the X-band thermionic cathode RF gun. The peak beam energy is 2 MeV. This experimental high energy ({approx}2 MeV) beam generation from the X-band thermionic cathode RF gun is the first in the world. In this paper, we describe the system of the Compton scattering X-ray source based on the X-band linac, experimental results of X-band thermionic cathode RF gun and the details of the experimental setup for Compton scattering X-ray generation that are under construction.

  10. Study of the X-ray Source Population and the Dark Matter Halo in Dwarf Spheroidal Galaxiess

    NASA Astrophysics Data System (ADS)

    Sasaki, Manami; Saeedi, Sara; Ducci, Lorenzo

    2015-09-01

    The Local Group of galaxies consists of the large spiral galaxies Milky Way, M31, and M33, and a large number of dwarf galaxies. Most of the galaxies are dwarf spheroidal (dSph) galaxies, which are the least luminous galaxies with the largest mass-to-light ratios. In general, dSphs show no recent star formation, which means that they are ideal laboratories to study the old, pristine stellar populations formed in the earliest epochs of chemical enrichment of the Universe. Observations with today's X-ray telescopes have revealed X-ray sources in the fields of the dSphs that are satellites of our Milky Way. The study of X-ray source population in these galaxies and their X-ray luminosity function will help us to understand the source population in galaxies at the early stages of galaxy evolution. Moreover, the existence of X-ray binaries in these galaxies, if confirmed, would indicate that these galaxies are able to retain their compact objects, which are believed to obtain high kick-velocities at their birth in asymmetric supernova explosions. Therefore, the search for and the study of X-ray sources in dSph galaxies in the Local Group will enable us to constrain the mass of dark matter in these galaxies and test different models of the formation and growth of galaxies out of primordial dark-matter halos.I will discuss, how, owing to the large effective area, large field of view and high spatial and time resolution, Athena and its WFI will make it possible to obtain unprecedented observational data of the stellar populations in primordial galaxies and dark-matter halo distribution in our Local Group through the study of high-energy sources.

  11. On the Nature of the Eclipsing Bright X-ray Source in the Circinus Galaxy Field

    NASA Technical Reports Server (NTRS)

    Weisskopf, M. C.; Wu, K.; Tennant, A. F.; Swartz, D. A.

    2003-01-01

    The X-ray spectrum and light curve of the bright source CG X-1 in the field of the Circinus galaxy are re-examined. Previous analyses have concluded that the source is an accreting black hole of about 50 solar masses although it was noted that the light curve resembles that of an AM Her-type system. Here we show that the light curve and orbital dynamics constrain the mass of the compact object to less than 30 solar masses and the mass of the companion to less than 1 solar mass. Combining the mass constraints with the observed X-ray flux, we show that an accreting object must either radiate anisotropically or strongly violate the Eddington limit. If the emission is beamed, then the companion star, which intercepts this flux during eclipse, will be driven out of thermal equilibrium and evaporate within approx. 103 yr. We find, therefore, that the observations are most consistent with the interpretation of CG X-1 as a bright, long-period, AM Her system in the Milky Way.

  12. X-ray solution scattering of squid heavy meromyosin: strengthening the evidence for an ancient compact off state.

    PubMed

    Gillilan, Richard E; Kumar, V S Senthil; O'Neall-Hennessey, Elizabeth; Cohen, Carolyn; Brown, Jerry H

    2013-01-01

    The overall conformations of regulated myosins or heavy meromyosins from chicken/turkey, scallop, tarantula, limulus, and scorpion sources have been studied by a number of techniques, including electron microscopy, sedimentation, and pulsed electron paramagnetic resonance. These studies have indicated that the binding of regulatory ions changes the conformation of the molecule from a compact shape found in the "off" state of the muscle to extended relationships between the tail and independently mobile heads that predominate in the "on" state. Here we strengthen the argument for the generality of this conformational change by using small angle X-ray scattering on heavy meromyosin from squid. Small angle X-ray scattering allows the protein to be visualized in solution under mild and relatively physiological conditions, and squid differs from the other species studied by at least 500 million years of evolution. Analysis of the data indicates that upon addition of Ca(2+) the radius of gyration increases. Differences in the squid "on" and "off" states are clearly distinguishable as bimodal and unimodal pair distance distribution functions respectively. These observations are consistent with a Ca(2+)-free squid heavy meromyosin that is compact, but which becomes extended when Ca(2+) is bound. Further, the scattering profile derived from the current model of tarantula heavy meromyosin in the "off" state is in excellent agreement with the measured "off" state scattering profile for squid heavy meromyosin. The previous and current studies together provide significant evidence that regulated myosin's compact off-state conformation is an ancient trait, inherited from a common ancestor during divergent evolution.

  13. X-ray solution scattering of squid heavy meromyosin: strengthening the evidence for an ancient compact off state.

    PubMed

    Gillilan, Richard E; Kumar, V S Senthil; O'Neall-Hennessey, Elizabeth; Cohen, Carolyn; Brown, Jerry H

    2013-01-01

    The overall conformations of regulated myosins or heavy meromyosins from chicken/turkey, scallop, tarantula, limulus, and scorpion sources have been studied by a number of techniques, including electron microscopy, sedimentation, and pulsed electron paramagnetic resonance. These studies have indicated that the binding of regulatory ions changes the conformation of the molecule from a compact shape found in the "off" state of the muscle to extended relationships between the tail and independently mobile heads that predominate in the "on" state. Here we strengthen the argument for the generality of this conformational change by using small angle X-ray scattering on heavy meromyosin from squid. Small angle X-ray scattering allows the protein to be visualized in solution under mild and relatively physiological conditions, and squid differs from the other species studied by at least 500 million years of evolution. Analysis of the data indicates that upon addition of Ca(2+) the radius of gyration increases. Differences in the squid "on" and "off" states are clearly distinguishable as bimodal and unimodal pair distance distribution functions respectively. These observations are consistent with a Ca(2+)-free squid heavy meromyosin that is compact, but which becomes extended when Ca(2+) is bound. Further, the scattering profile derived from the current model of tarantula heavy meromyosin in the "off" state is in excellent agreement with the measured "off" state scattering profile for squid heavy meromyosin. The previous and current studies together provide significant evidence that regulated myosin's compact off-state conformation is an ancient trait, inherited from a common ancestor during divergent evolution. PMID:24358137

  14. Compact soft x-ray multichord camera: Design and initial operation

    NASA Astrophysics Data System (ADS)

    Franz, P.; Gadani, G.; Pasqualotto, R.; Marrelli, L.; Martin, P.; Spizzo, G.; Brunsell, P.; Chapman, B. E.; Paganucci, F.; Rossetti, P.; Xiao, C.

    2003-03-01

    A compact and low cost diagnostic for spatially resolved measurements of soft x-ray or total radiation emission has been designed and realized to be flexibly applied to different plasma physics experiments. Its reduced size (outer diameter=35 mm) makes it suited to a variety of devices. The line integrated emissivity (brightness) has been measured along up to 20 lines of sight, using an array of miniaturized silicon photodiodes. Preliminary prototypes of the diagnostic have been installed in the Madison Symmetric Torus reversed field pinch (RFP) device at University of Wisconsin and in the EXTRAP T2 RFP device at the Royal Institute of Technology in Stockholm. Application of the diagnostic to a gas-fed (argon, helium) magnetoplasma dynamic thruster (MPDT) with an external magnetic field will also be discussed.

  15. Carbon nanotube based microfocus field emission x-ray source for microcomputed tomography

    SciTech Connect

    Liu Zejian; Yang Guang; Lee, Yueh Z.; Bordelon, David; Lu Jianping; Zhou, Otto

    2006-09-04

    Microcomputed tomography is now widely used for in vivo small animal imaging for cancer studies. Achieving high imaging quality of live objects requires the x-ray source to have both high spatial and temporal resolutions. Preliminary studies have shown that carbon nanotube (CNT) based field emission x-ray source has significant intrinsic advantages over the conventional thermionic x-ray tube including better temporal resolution and programmability. Here we report the design and characterization of a CNT based field emission x-ray source that also affords a high spatial resolution. The device uses modified asymmetric Einzel lenses for electron focusing and an elliptical shaped CNT cathode patterned by photolithography. Stable and small isotropic x-ray focal spot sizes were obtained.

  16. Optimal focusing for a linac-based hard x-ray source

    SciTech Connect

    Liu, C.; Krafft, G.; Talman, R.

    2011-03-28

    In spite of having a small average beam current limit, a linac can have features that make it attractive as an x-ray source: high energy, ultralow emittance and energy spread, and flexible beamline optics. Unlike a storage ring, in which an (undulator) radiation source is necessarily short and positioned at an electron beam waist, in a linac the undulator can be long and the electron beam can be adjusted to have a (virtual) waist far downstream toward the x-ray target. Using a planned CEBAF beamline as an example, this paper shows that a factor of 2000 in beam current can be overcome to produce a monochromatic hard x-ray source comparable with, or even exceeding, the performance of an x-ray line at a third generation storage ring. Optimal electron beam focusing conditions for x-ray flux density and brilliance are derived, and are verified by simulations using the SRW code.

  17. A fine-focusing x-ray source using carbon-nanofiber field emitter

    NASA Astrophysics Data System (ADS)

    Sugimoto, W.; Sugita, S.; Sakai, Y.; Goto, H.; Watanabe, Y.; Ohga, Y.; Kita, S.; Ohara, T.

    2010-08-01

    A fine-focusing x-ray source has been constructed employing a field electron emitter prepared by growing carbon-nanofibers (CNFs) on a metal tip. The x-ray source is composed of a CNF field electron emitter, an electrostatic lens, two magnetic lenses, and a W-target for generating x-rays by electron impact. The CNFs provided field electrons with a current density of J ˜5×109 A/m2, which was evaluated with the aid of Fowler-Nordheim theory. The electron beam extracted from the CNF emitter was accelerated to the energies of E =10-25 keV, and then focused by the lenses. By recording the x-ray images of test charts, the optimum resolution of the x-ray source was estimated to be approximately Dx=0.5 μm.

  18. Hard X-Ray Flare Source Sizes Measured with the Ramaty High Energy Solar Spectroscopic Imager

    NASA Technical Reports Server (NTRS)

    Dennis, Brian R.; Pernak, Rick L.

    2009-01-01

    Ramaty High Energy Solar Spectroscopic Imager (RHESSI) observations of 18 double hard X-ray sources seen at energies above 25 keV are analyzed to determine the spatial extent of the most compact structures evident in each case. The following four image reconstruction algorithms were used: Clean, Pixon, and two routines using visibilities maximum entropy and forward fit (VFF). All have been adapted for this study to optimize their ability to provide reliable estimates of the sizes of the more compact sources. The source fluxes, sizes, and morphologies obtained with each method are cross-correlated and the similarities and disagreements are discussed. The full width at half-maximum (FWHM) of the major axes of the sources with assumed elliptical Gaussian shapes are generally well correlated between the four image reconstruction routines and vary between the RHESSI resolution limit of approximately 2" up to approximately 20" with most below 10". The FWHM of the minor axes are generally at or just above the RHESSI limit and hence should be considered as unresolved in most cases. The orientation angles of the elliptical sources are also well correlated. These results suggest that the elongated sources are generally aligned along a flare ribbon with the minor axis perpendicular to the ribbon. This is verified for the one flare in our list with coincident Transition Region and Coronal Explorer (TRACE) images. There is evidence for significant extra flux in many of the flares in addition to the two identified compact sources, thus rendering the VFF assumption of just two Gaussians inadequate. A more realistic approximation in many cases would be of two line sources with unresolved widths. Recommendations are given for optimizing the RHESSI imaging reconstruction process to ensure that the finest possible details of the source morphology become evident and that reliable estimates can be made of the source dimensions.

  19. A vacuum-sealed compact x-ray tube based on focused carbon nanotube field-emission electrons

    NASA Astrophysics Data System (ADS)

    Jeong, Jin-Woo; Kim, Jae-Woo; Kang, Jun-Tae; Choi, Sungyoul; Ahn, Seungjoon; Song, Yoon-Ho

    2013-03-01

    We report on a fully vacuum-sealed compact x-ray tube based on focused carbon nanotube (CNT) field-emission electrons for various radiography applications. The specially designed two-step brazing process enabled us to accomplish a good vacuum level for the stable and reliable operation of the x-ray tube without any active vacuum pump. Also, the integrated focusing electrodes in the field-emission electron gun focused electron beams from the CNT emitters onto the anode target effectively, giving a small focal spot of around 0.3 mm with a large current of above 50 mA. The active-current control through the cathode electrode of the x-ray tube led a fast digital modulation of x-ray dose with a low voltage of below 5 V. The fabricated compact x-ray tube showed a stable and reliable operation, indicating good maintenance of a vacuum level of below 5 × 10-6 Torr and the possibility of field-emission x-ray tubes in a stand-alone device without an active pumping system.

  20. A vacuum-sealed compact x-ray tube based on focused carbon nanotube field-emission electrons.

    PubMed

    Jeong, Jin-Woo; Kim, Jae-Woo; Kang, Jun-Tae; Choi, Sungyoul; Ahn, Seungjoon; Song, Yoon-Ho

    2013-03-01

    We report on a fully vacuum-sealed compact x-ray tube based on focused carbon nanotube (CNT) field-emission electrons for various radiography applications. The specially designed two-step brazing process enabled us to accomplish a good vacuum level for the stable and reliable operation of the x-ray tube without any active vacuum pump. Also, the integrated focusing electrodes in the field-emission electron gun focused electron beams from the CNT emitters onto the anode target effectively, giving a small focal spot of around 0.3 mm with a large current of above 50 mA. The active-current control through the cathode electrode of the x-ray tube led a fast digital modulation of x-ray dose with a low voltage of below 5 V. The fabricated compact x-ray tube showed a stable and reliable operation, indicating good maintenance of a vacuum level of below 5 × 10(-6) Torr and the possibility of field-emission x-ray tubes in a stand-alone device without an active pumping system.

  1. In-situ X-ray diffraction system using sources and detectors at fixed angular positions

    DOEpatents

    Gibson, David M.; Gibson, Walter M.; Huang, Huapeng

    2007-06-26

    An x-ray diffraction technique for measuring a known characteristic of a sample of a material in an in-situ state. The technique includes using an x-ray source for emitting substantially divergent x-ray radiation--with a collimating optic disposed with respect to the fixed source for producing a substantially parallel beam of x-ray radiation by receiving and redirecting the divergent paths of the divergent x-ray radiation. A first x-ray detector collects radiation diffracted from the sample; wherein the source and detector are fixed, during operation thereof, in position relative to each other and in at least one dimension relative to the sample according to a-priori knowledge about the known characteristic of the sample. A second x-ray detector may be fixed relative to the first x-ray detector according to the a-priori knowledge about the known characteristic of the sample, especially in a phase monitoring embodiment of the present invention.

  2. THE CHANDRA LOCAL VOLUME SURVEY: THE X-RAY POINT-SOURCE CATALOG OF NGC 300

    SciTech Connect

    Binder, B.; Williams, B. F.; Dalcanton, J. J.; Anderson, S. F.; Weisz, D. R.; Eracleous, M.; Gaetz, T. J.; Plucinsky, P. P.; Skillman, E. D.; Kong, A. K. H.

    2012-10-10

    We present the source catalog of a new Chandra ACIS-I observation of NGC 300 obtained as part of the Chandra Local Volume Survey. Our 63 ks exposure covers {approx}88% of the D{sub 25} isophote (R Almost-Equal-To 6.3 kpc) and yields a catalog of 95 X-ray point sources detected at high significance to a limiting unabsorbed 0.35-8 keV luminosity of {approx}10{sup 36} erg s{sup -1}. Sources were cross-correlated with a previous XMM-Newton catalog, and we find 75 'X-ray transient candidate' sources that were detected by one observatory, but not the other. We derive an X-ray scale length of 1.7 {+-} 0.2 kpc and a recent star formation rate of 0.12 M{sub Sun} yr{sup -1} in excellent agreement with optical observations. Deep, multi-color imaging from the Hubble Space Telescope, covering {approx}32% of our Chandra field, was used to search for optical counterparts to the X-ray sources, and we have developed a new source classification scheme to determine which sources are likely X-ray binaries, supernova remnants, and background active galactic nucleus candidates. Finally, we present the X-ray luminosity functions (XLFs) at different X-ray energies, and we find the total NGC 300 X-ray point-source population to be consistent with other late-type galaxies hosting young stellar populations ({approx}< 50 Myr). We find that XLF of sources associated with older stellar populations has a steeper slope than the XLF of X-ray sources coinciding with young stellar populations, consistent with theoretical predictions.

  3. X-ray microscopy and imaging of Caenorhabditis elegans nematode using a laser-plasma-pulsed x-ray source

    NASA Astrophysics Data System (ADS)

    Poletti, Giulio; Orsini, Franceasco; Ullschmied, Jiri; Skala, Jiri; Kralikova, Bozena; Pfeifer, Miroslav; Kadlec, Christelle; Mocek, Tomas; Prag, A. R.; Cotelli, F.; Lora Lamia, C.; Batani, Dimitri; Bernardinello, A.; Desai, Tara; Zullini, A.

    2004-01-01

    An experiment on Soft X-ray Contact Microscopy (SXCM) performed on Caenorhabditis elegans nematodes is discussed. This sample has been selected since it is a well studied case used as model in many biological contexts. The experiment has been performed using the iodine PALS laser source to generate pulsed soft X-rays from laser-plasma interaction, using molybdenum and gold as targets. Typical intensities on the targets exceeded 1014 W/cm2. The SXCM imprints have been recorded on Polymethilmetacrylate (PMMA) photo resists which have been chemically developed and analyzed with an Atomic Force Microscope (AFM) operating in constant force mode. The use of error signal AFM images together with topography AFM images, did allow an easier recognition of biological patterns, and the identification of observed structures with internal organs. Several organs were identified in the SXCM images, including cuticle annuli, alae, pharynx, and three different types of cell nuclei. These are the first SXCM images of multi-cellular complex organisms.

  4. Novel multi-beam X-ray source for vacuum electronics enabled medical imaging applications

    NASA Astrophysics Data System (ADS)

    Neculaes, V. Bogdan

    2013-10-01

    For almost 100 of years, commercial medical X-ray applications have relied heavily on X-ray tube architectures based on the vacuum electronics design developed by William Coolidge at the beginning of the twentieth century. Typically, the Coolidge design employs one hot tungsten filament as the electron source; the output of the tube is one X-ray beam. This X-ray source architecture is the state of the art in today's commercial medical imaging applications, such as Computed Tomography. Recently, GE Global Research has demonstrated the most dramatic extension of the Coolidge vacuum tube design for Computed Tomography (CT) in almost a century: a multi-beam X-ray source containing thirty two cathodes emitting up to 1000 mA, in a cathode grounded - anode at potential architecture (anode up to 140 kV). This talk will present the challenges of the X-ray multi-beam vacuum source design - space charge electron gun design, beam focusing to compression ratios needed in CT medical imaging applications (image resolution is critically dependent on how well the electron beam is focused in vacuum X-ray tubes), electron emitter choice to fit the aggressive beam current requirements, novel electronics for beam control and focusing, high voltage and vacuum solutions, as well as vacuum chamber design to sustain the considerable G forces typically encountered on a CT gantry (an X-ray vacuum tube typically rotates on the CT gantry at less than 0.5 s per revolution). Consideration will be given to various electron emitter technologies available for this application - tungsten emitters, dispenser cathodes and carbon nano tubes (CNT) - and their tradeoffs. The medical benefits potentially enabled by this unique vacuum multi-beam X-ray source are: X-ray dose reduction, reduction of image artifacts and improved image resolution. This work was funded in part by NIH grant R01EB006837.

  5. VLA observations of a complete sample of extragalactic X-ray sources. II

    NASA Technical Reports Server (NTRS)

    Schild, R.; Zamorani, G.; Gioia, I. M.; Feigelson, E. D.; Maccacaro, T.

    1983-01-01

    A complete sample of 35 X-ray selected sources found with the Einstein Observatory has been observed with the Very Large Array at 6 cm to investigate the relationship between radio and X-ray emission in extragalactic objects. Detections include three active galactic nuclei (AGNs), two clusters or groups of galaxies, two individual galaxies, and two BL Lac objects. The frequency of radio emission in X-ray selected AGNs is compared with that of optically selected quasars using the integral radio-optical luminosity function. The result suggests that the probability for X-ray selected quasars to be radio sources is higher than for those optically selected. No obvious correlation is found in the sample between the richness of X-ray luminosity of the cluster and the presence of a galaxy with radio luminosity at 5 GHz larger than 10 to the 30th ergs/s/Hz.

  6. Numerical simulation for all-optical Thomson scattering X-ray source

    NASA Astrophysics Data System (ADS)

    Tan, Fang; Zhu, Bin; Han, Dan; Xin, Jian-Ting; Zhao, Zong-Qing; Cao, Lei-Feng; Gu, Yu-Qiu; Zhang, Bao-Han

    2014-03-01

    Energy spectra, angular distributions, and temporal profiles of the photons produced by an all-optical Thomson scattering X-ray source are explored through numerical simulations based on the parameters of the SILEX-I laser system (800 nm, 30 fs, 300 TW) and the previous wakefield acceleration experimental results. The simulation results show that X-ray pulses with a duration of 30 fs and an emission angle of 50 mrad can be produced from such a source. Using the optimized electron parameters, X-ray pulses with better directivity and narrower energy spectra can be obtained. Besides the electron parameters, the laser parameters such as the wavelength, pulse duration, and spot size also affect the X-ray yield, the angular distribution, and the maximum photon energy, except the X-ray pulse duration which is slightly changed for the case of ultrafast laser—electron interaction.

  7. The Munich Compact Light Source: initial performance measures.

    PubMed

    Eggl, Elena; Dierolf, Martin; Achterhold, Klaus; Jud, Christoph; Günther, Benedikt; Braig, Eva; Gleich, Bernhard; Pfeiffer, Franz

    2016-09-01

    While large-scale synchrotron sources provide a highly brilliant monochromatic X-ray beam, these X-ray sources are expensive in terms of installation and maintenance, and require large amounts of space due to the size of storage rings for GeV electrons. On the other hand, laboratory X-ray tube sources can easily be implemented in laboratories or hospitals with comparatively little cost, but their performance features a lower brilliance and a polychromatic spectrum creates problems with beam hardening artifacts for imaging experiments. Over the last decade, compact synchrotron sources based on inverse Compton scattering have evolved as one of the most promising types of laboratory-scale X-ray sources: they provide a performance and brilliance that lie in between those of large-scale synchrotron sources and X-ray tube sources, with significantly reduced financial and spatial requirements. These sources produce X-rays through the collision of relativistic electrons with infrared laser photons. In this study, an analysis of the performance, such as X-ray flux, source size and spectra, of the first commercially sold compact light source, the Munich Compact Light Source, is presented. PMID:27577768

  8. The Munich Compact Light Source: initial performance measures.

    PubMed

    Eggl, Elena; Dierolf, Martin; Achterhold, Klaus; Jud, Christoph; Günther, Benedikt; Braig, Eva; Gleich, Bernhard; Pfeiffer, Franz

    2016-09-01

    While large-scale synchrotron sources provide a highly brilliant monochromatic X-ray beam, these X-ray sources are expensive in terms of installation and maintenance, and require large amounts of space due to the size of storage rings for GeV electrons. On the other hand, laboratory X-ray tube sources can easily be implemented in laboratories or hospitals with comparatively little cost, but their performance features a lower brilliance and a polychromatic spectrum creates problems with beam hardening artifacts for imaging experiments. Over the last decade, compact synchrotron sources based on inverse Compton scattering have evolved as one of the most promising types of laboratory-scale X-ray sources: they provide a performance and brilliance that lie in between those of large-scale synchrotron sources and X-ray tube sources, with significantly reduced financial and spatial requirements. These sources produce X-rays through the collision of relativistic electrons with infrared laser photons. In this study, an analysis of the performance, such as X-ray flux, source size and spectra, of the first commercially sold compact light source, the Munich Compact Light Source, is presented.

  9. A new compact soft x-ray spectrometer for resonant inelastic x-ray scattering studies at PETRA III

    SciTech Connect

    Yin, Z. E-mail: simone.techert@desy.de; Peters, H. B.; Hahn, U.; Viefhaus, J.; Agåker, M.; Nordgren, J.; Hage, A.; Reininger, R.; Siewert, F.; Techert, S. E-mail: simone.techert@desy.de

    2015-09-15

    We present a newly designed compact grating spectrometer for the energy range from 210 eV to 1250 eV, which would include the Kα{sub 1,2} emission lines of vital elements like C, N, and O. The spectrometer is based on a grazing incidence spherical varied line spacing grating with 2400 l/mm at its center and a radius of curvature of 58 542 mm. First, results show a resolving power of around 1000 at an energy of 550 eV and a working spectrometer for high vacuum (10{sup −4} mbar) environment without losing photon intensity.

  10. Tomography of human trabecular bone with a laser-wakefield driven x-ray source

    NASA Astrophysics Data System (ADS)

    Cole, J. M.; Wood, J. C.; Lopes, N. C.; Poder, K.; Abel, R. L.; Alatabi, S.; Bryant, J. S. J.; Jin, A.; Kneip, S.; Mecseki, K.; Parker, S.; Symes, D. R.; Sandholzer, M. A.; Mangles, S. P. D.; Najmudin, Z.

    2016-01-01

    A laser-wakefield driven x-ray source is used for the radiography of human bone. The betatron motion of accelerated electrons generates x-rays which are hard (critical energy {{E}\\text{crit}}>30 keV), have small source size (<3 μm) and high average brightness. The x-rays are generated from a helium gas cell which is near-instantly replenishable, and thus the average photon flux is limited by the repetition rate of the driving laser rather than the breakdown of the x-ray source. A tomograph of a human bone sample was recorded with a resolution down to 50 μm. The photon flux was sufficiently high that a radiograph could be taken with each laser shot, and the fact that x-ray beams were produced on 97% of shots minimised failed shots and facilitated full micro-computed tomography in a reasonable time scale of several hours, limited only by the laser repetition rate. The x-ray imaging beamline length (not including the laser) is shorter than that of a synchrotron source due to the high accelerating fields and small source size. Hence this interesting laboratory-based source may one day bridge the gap between small microfocus x-ray tubes and large synchrotron facilities.

  11. X-ray Spectral Measurements of the JMAR High-Power Laser-plasma Source

    NASA Astrophysics Data System (ADS)

    Whitlock, Robert R.; Dozier, Charles M.; Newman, Daniel A.; Turcu, I. C. Edmond; Gaeta, Celestino J.; Cassidy, Kelly L.; Powers, Michael F.; Kleindolph, Thomas; Morris, James H.; Forber, Richard A.

    2002-10-01

    X-ray spectra of Cu plasmas at the focus of a four-beam, solid-state diode-pumped laser have been recorded. This laser-plasma X-ray source is being developed for JMAR's lithography systems aimed at high- performance semiconductor integrated circuits. The unique simultaneous overlay of the four sub-nanosecond laser beams at 300 Hertz produces a bright, point-plasma X-ray source. PIN diode measurements of the X-ray output indicate that the conversion efficiency (ratio of X-ray emission energy into 2π steradians to incident laser energy) was approximately 9 percent with average X-ray power yields of greater than 10 Watts. Spectra were recorded on calibrated Kodak DEF film in a curved-crystal spectrograph. A KAP crystal (2d = 26.6 Angstroms) was used to disperse the 900 eV to 3000 eV spectral energies onto the film. Preliminary examination of the films indicated the existence of Cu and Cu XX ionization states. Additional spectra as a function of laser input power were also recorded to investigate potential changes in X-ray yields. These films are currently being analyzed. The analysis of the spectra provide absolute line and continuum intensities, and total X-ray output in the measured spectral range.

  12. Diagnosing the accretion flow in ultraluminous X-ray sources using soft X-ray atomic features

    NASA Astrophysics Data System (ADS)

    Middleton, Matthew J.; Walton, Dominic J.; Fabian, Andrew; Roberts, Timothy P.; Heil, Lucy; Pinto, Ciro; Anderson, Gemma; Sutton, Andrew

    2015-12-01

    The lack of unambiguous detections of atomic features in the X-ray spectra of ultraluminous X-ray sources (ULXs) has proven a hindrance in diagnosing the nature of the accretion flow. The possible association of spectral residuals at soft energies with atomic features seen in absorption and/or emission and potentially broadened by velocity dispersion could therefore hold the key to understanding much about these enigmatic sources. Here we show for the first time that such residuals are seen in several sources and appear extremely similar in shape, implying a common origin. Via simple arguments we assert that emission from extreme colliding winds, absorption in a shell of material associated with the ULX nebula and thermal plasma emission associated with star formation are all highly unlikely to provide an origin. Whilst CCD spectra lack the energy resolution necessary to directly determine the nature of the features (i.e. formed of a complex of narrow lines or intrinsically broad lines), studying the evolution of the residuals with underlying spectral shape allows for an important, indirect test for their origin. The ULX NGC 1313 X-1 provides the best opportunity to perform such a test due to the dynamic range in spectral hardness provided by archival observations. We show through highly simplified spectral modelling that the strength of the features (in either absorption or emission) appears to anticorrelate with spectral hardness, which would rule out an origin via reflection of a primary continuum and instead supports a picture of atomic transitions in a wind or nearby material associated with such an outflow.

  13. Infrared Counterparts to Chandra X-Ray Sources in the Antennae

    NASA Astrophysics Data System (ADS)

    Clark, D. M.; Eikenberry, S. S.; Brandl, B. R.; Wilson, J. C.; Carson, J. C.; Henderson, C. P.; Hayward, T. L.; Barry, D. J.; Ptak, A. F.; Colbert, E. J. M.

    2007-03-01

    We use deep J (1.25 μm) and Ks (2.15 μm) images of the Antennae (NGC 4038/4039) obtained with the Wide-field InfraRed Camera on the Palomar 200 inch (5 m) telescope, together with the Chandra X-ray source list of Zezas and coworkers to search for infrared counterparts to X-ray point sources. We establish an X-ray/IR astrometric frame tie with ~0.5" rms residuals over a ~4.3' field. We find 13 ``strong'' IR counterparts brighter than Ks=17.8 mag and <1.0" from X-ray sources, and an additional 6 ``possible'' IR counterparts between 1.0'' and 1.5'' from X-ray sources. Based on a detailed study of the surface density of IR sources near the X-ray sources, we expect only ~2 of the ``strong'' counterparts and ~3 of the ``possible'' counterparts to be chance superpositions of unrelated objects. Comparing both strong and possible IR counterparts to our photometric study of ~220 IR clusters in the Antennae, we find with a >99.9% confidence level that IR counterparts to X-ray sources are ΔMKs~1.2 mag more luminous than average non-X-ray clusters. We also note that the X-ray/IR matches are concentrated in the spiral arms and ``overlap'' regions of the Antennae. This implies that these X-ray sources lie in the most ``super'' of the Antennae's super star clusters, and thus trace the recent massive star formation history here. Based on the NH inferred from the X-ray sources without IR counterparts, we determine that the absence of most of the ``missing'' IR counterparts is not due to extinction, but that these sources are intrinsically less luminous in the IR, implying that they trace a different (possibly older) stellar population. We find no clear correlation between X-ray luminosity classes and IR properties of the sources, although small-number statistics hamper this analysis.

  14. Evidence For Quasi-Periodic X-ray Dips From An Ultraluminous X-ray Source: Implications for the Binary Motion

    NASA Technical Reports Server (NTRS)

    Pasham, Dheeraj R.; Strohmayer, Tod E.

    2013-01-01

    We report results from long-term (approx.1240 days) X-ray (0.3-8.0 keV) monitoring of the ultraluminous X-ray source NGC 5408 X-1 with the Swift/X-Ray Telescope. Here we expand on earlier work by Strohmayer (2009) who used only a part of the present data set. Our primary results are: (1) the discovery of sharp, quasi-periodic, energy-independent dips in the X-ray intensity that recur on average every 243 days, (2) the detection of an energy dependent (variability amplitude decreases with increasing energy), quasi-sinusoidal X-ray modulation with a period of 112.6 +/- 4 days, the amplitude of which weakens during the second half of the light curve, and (3) spectral evidence for an increase in photoelectric absorption during the last continuous segment of the data. We interpret the X-ray modulations within the context of binary motion in analogy to that seen in high-inclination accreting X-ray binaries. If correct, this implies that NGC 5408 X-1 is in a binary with an orbital period of 243 +/- 23 days, in contrast to the 115.5 day quasi-sinusoidal period previously reported by Strohmayer (2009). We discuss the overall X-ray modulation within the framework of accretion via Roche-lobe overflow of the donor star. In addition, if the X-ray modulation is caused by vertically structured obscuring material in the accretion disk, this would imply a high value for the inclination of the orbit. A comparison with estimates from accreting X-ray binaries suggests an inclination > or approx.70deg. We note that, in principle, a precessing accretion disk could also produce the observed X-ray modulations.

  15. Probing cluster potentials through gravitational lensing of background X-ray sources

    NASA Technical Reports Server (NTRS)

    Refregier, A.; Loeb, A.

    1996-01-01

    The gravitational lensing effect of a foreground galaxy cluster, on the number count statistics of background X-ray sources, was examined. The lensing produces a deficit in the number of resolved sources in a ring close to the critical radius of the cluster. The cluster lens can be used as a natural telescope to study the faint end of the (log N)-(log S) relation for the sources which account for the X-ray background.

  16. Using X-rays to determine which compact groups are illusory

    NASA Technical Reports Server (NTRS)

    Ostriker, Jeremiah P.; Lubin, Lori M.; Hernquist, Lars

    1995-01-01

    If the large-scale galaxy distribution is filamentary, as suggested by some observations and recent hydrodynamical simulations, then lengthwise views of filaments will apparently produce compact groups (CGs) that are in reality stretched out along the line of sight. This possibility has been advocated recently by Hernquist, Katz, & Weinberg (1995). Here we propose a test for this hypothesis using X-ray emission from CGs. The observable quantity Q identical with L(sub x)a(sup 3)(sup p)/(L(sup 2)(sup g))T(sup 1/2)(sub x) should be proportional to the axis ratio of the group, a/c, where a and c are the short and long axes of a prolate distribution, a(sub p) is the radius of the group projected onto the sky, L(sub x) is the bolometric X-ray luminosity, L(sub g) is the group blue luminosity, and T(sub x) is the gas temperature. We find that the distribution of Q is consistent with the notion that many CGs with unusually small values of a/c are frauds, i.e., that the values of Q are anomalously small. Absent other information, it is equally possible that CGs are very gas-poor relative to rich clusters; however, this can be tested using the Sunyaev-Zeldovich effect. If the groups have a close to normal ratio of gas to total mass, but are simply stretched out along the line of sight, a Sunyaev-Zeldovich signal should be detectable.

  17. Tailoring a plasma focus as hard x-ray source for imaging

    SciTech Connect

    Hussain, S.; Shafiq, M.; Zakaullah, M.

    2010-01-18

    An investigation on temporal and spatial properties of hard x-rays (15-88 keV) emitted in a 5.3 kJ plasma focus using Si pin diodes and a pinhole camera is reported. The maximum yield of hard x-rays of 15-88 keV range is estimated about 4.7 J and corresponding efficiency for x-ray generation is 0.09%. The x-rays with energy >15 keV have 15-20 ns pulse duration and approx1 mm source size. This radiation is used for contact x-ray imaging of biological and compound objects and spatial resolution of approx50 mum is demonstrated.

  18. Tailoring a plasma focus as hard x-ray source for imaging

    NASA Astrophysics Data System (ADS)

    Hussain, S.; Shafiq, M.; Zakaullah, M.

    2010-01-01

    An investigation on temporal and spatial properties of hard x-rays (15-88 keV) emitted in a 5.3 kJ plasma focus using Si pin diodes and a pinhole camera is reported. The maximum yield of hard x-rays of 15-88 keV range is estimated about 4.7 J and corresponding efficiency for x-ray generation is 0.09%. The x-rays with energy >15 keV have 15-20 ns pulse duration and ˜1 mm source size. This radiation is used for contact x-ray imaging of biological and compound objects and spatial resolution of ˜50 μm is demonstrated.

  19. The X-ray spectral evolution of the ultraluminous X-ray source Holmberg IX X-1

    NASA Astrophysics Data System (ADS)

    Luangtip, Wasutep; Roberts, Timothy P.; Done, Chris

    2016-08-01

    We present a new analysis of X-ray spectra of the archetypal ultraluminous X-ray source (ULX) Holmberg IX X-1 obtained by the Swift, XMM-Newton and NuSTAR observatories. This ULX is a persistent source, with a typical luminosity of ˜1040 erg s-1, that varied by a factor of 4-5 over eight years. We find that its spectra tend to evolve from relatively flat or two-component spectra in the medium energy band (1-6 keV), at lower luminosities, to a spectrum that is distinctly curved and disc-like at the highest luminosities, with the peak energy in the curved spectrum tending to decrease with increased luminosity. We argue that the spectral evolution of the ULX can be explained by super-Eddington accretion models, where in this case we view the ULX down the evacuated funnel along its rotation axis, bounded by its massive radiatively driven wind. The spectral changes then originate in enhanced geometric beaming as the accretion rate increases and wind funnel narrows, causing the scattered flux from the central regions of the supercritical flow to brighten faster than the isotropic thermal emission from the wind, and so the curved hard spectral component to dominate at the highest luminosities. The wind also Compton down-scatters photons at the edge of the funnel, resulting in the peak energy of the spectrum decreasing. We also confirm that Holmberg IX X-1 displays spectral degeneracy with luminosity, and suggest that the observed differences are naturally explained by precession of the black hole rotation axis for the suggested wind geometry.

  20. Catalytic action of β source on x-ray emission from plasma focus

    NASA Astrophysics Data System (ADS)

    Ahmad, S.; Sadiq, Mehboob; Hussain, S.; Shafiq, M.; Zakaullah, M.; Waheed, A.

    2006-01-01

    The influence of preionization around the insulator sleeve by a mesh-type β source (Ni6328) for the x-ray emission from a (2.3-3.9 kJ) plasma focus device is investigated. Quantrad Si p-i-n diodes along with suitable filters are employed as time-resolved x-ray detectors and a multipinhole camera with absorption filters is used for time-integrated analysis. X-ray emission in 4π geometry is measured as a function of argon and hydrogen gas filling pressures with and without β source at different charging voltages. It is found that the pressure range for the x-ray emission is broadened, x-ray emission is enhanced, and shot to shot reproducibility is improved with the β source. With argon, the CuKα emission is estimated to be 27.14 J with an efficiency of 0.7% for β source and 21.5 J with an efficiency of 0.55% without β source. The maximum x-ray yield in 4π geometry is found to be about 68.90 J with an efficiency of 1.8% for β source and 54.58 J with an efficiency of 1.4% without β source. With hydrogen, CuKα emission is 11.82 J with an efficiency of 0.32% for β source and 10.07 J with an efficiency of 0.27% without β source. The maximum x-ray yield in 4π geometry is found to be 30.20 J with an efficiency of 0.77% for β source and 25.58 J with an efficiency of 0.6% without β source. The x-ray emission with Pb insert at the anode tip without β source is also investigated and found to be reproducible and significantly high. The maximum x-ray yield is estimated to be 46.6 J in 4π geometry with an efficiency of 1.4% at 23 kV charging voltage. However, degradation of x-ray yield is observed when charging voltage exceeds 23 kV for Pb insert. From pinhole images it is observed that the x-ray emission due to the bombardment of electrons at the anode tip is dominant in both with and without β source.

  1. On the large scale structure of X-ray background sources

    NASA Technical Reports Server (NTRS)

    Bi, H. G.; Meszaros, A.; Meszaros, P.

    1991-01-01

    The large scale clustering of the sources responsible for the X-ray background is discussed, under the assumption of a discrete origin. The formalism necessary for calculating the X-ray spatial fluctuations in the most general case where the source density contrast in structures varies with redshift is developed. A comparison of this with observational limits is useful for obtaining information concerning various galaxy formation scenarios. The calculations presented show that a varying density contrast has a small impact on the expected X-ray fluctuations. This strengthens and extends previous conclusions concerning the size and comoving density of large scale structures at redshifts 0.5 between 4.0.

  2. Omega Dante soft x-ray power diagnostic component calibration at the National Synchrotron Light Source

    NASA Astrophysics Data System (ADS)

    Campbell, K. M.; Weber, F. A.; Dewald, E. L.; Glenzer, S. H.; Landen, O. L.; Turner, R. E.; Waide, P. A.

    2004-10-01

    The Dante soft x-ray spectrometer, installed on the Omega laser facility at the Laboratory for Laser Energetics, University of Rochester, is a 12-channel filter-edge defined soft x-ray power diagnostic. It is used to measure the spectrally resolved, absolute flux from direct drive, indirect drive (hohlraums) and other plasma sources. Dante component calibration efforts using two beam lines, U3C (50 eV-1 keV) and X8A (1-6 keV) at the National Synchrotron Light Source have been implemented to improve the accuracy of these measurements. We have calibrated metallic vacuum x-ray diodes, mirrors and filters.

  3. Highly charged ion X-rays from Electron Cyclotron Resonance Ion Sources

    NASA Astrophysics Data System (ADS)

    Indelicato, P.; Boucard, S.; Covita, D. S.; Gotta, D.; Gruber, A.; Hirtl, A.; Fuhrmann, H.; Le Bigot, E.-O.; Schlesser, S.; dos Santos, J. M. F.; Simons, L. M.; Stingelin, L.; Trassinelli, M.; Veloso, J.; Wasser, A.; Zmeskal, J.

    2007-09-01

    Radiation from the highly charged ions contained in the plasma of Electron-Cyclotron Resonance Ion Sources (ECRISs) constitutes a very bright source of X-rays. Because the ions have a relatively low kinetic energy (≈1 eV) transitions can be very narrow, containing only a small Doppler broadening. We describe preliminary accurate measurements of two and three-electron ions with Z=16-18. We show how these measurement can test sensitively many-body relativistic calculations or can be used as X-ray standards for precise measurements of X-ray transitions in exotic atoms.

  4. Fresnel zone plates for Achromatic Imaging Survey of X-ray sources

    SciTech Connect

    Palit, Sourav; Chakrabarti, S. K.; Debnath, D.; Yadav, Vipin; Nandi, Anuj

    2008-10-08

    A telescope with Fresnel Zone Plates has been contemplated to be an excellent imaging mask in X-rays and gamma-rays for quite some time. With a proper choice of zone plate material, spacing and an appropriate readout system it is possible to achieve any theoretical angular resolution. We provide the results of numerical simulations of how a large number of X-ray sources could be imaged at a high resolution. We believe that such an imager would be an excellent tool for a future survey mission for X-ray and gamma-ray sources which we propose.

  5. Is the DA white dwarf 1910 + 047 a soft X-ray source?

    NASA Technical Reports Server (NTRS)

    Vennes, Stephane

    1990-01-01

    The possibility that the recently discovered DA white dwarf WD 1910 + 047 might be an Einstein soft X-ray source is studied, applying a complete model atmosphere analyis to both the optical and the soft X-ray data. It is found that the X-ray source in question is at least one order of magnitude too strong to be compatible with the estimated atmospheric parameters of the possible optical counterpart. The spatial coincidence between the two, however, remains extremely intriguing and has left us with the dilemma of accepting the relatively improbable coincidence of two unrelated objects or rejoicing over the discovery of a highly unusual one.

  6. Omega Dante Soft X-Ray Power Diagnostic Component Calibration at the National Synchrotron Light Source

    SciTech Connect

    Campbell, K; Weber, F; Dewald, E; Glenzer, S; Landen, O; Turner, R; Waide, P

    2004-04-15

    The Dante soft x-ray spectrometer installed on the Omega laser facility at the Laboratory for Laser Energetics, University of Rochester is a twelve-channel filter-edge defined x-ray power diagnostic. It is used to measure the absolute flux from direct drive, indirect drive (hohlraums) and other plasma sources. Calibration efforts using two beam lines, U3C (50eV-1keV) and X8A (1keV-6keV) at the National Synchrotron Light Source (NSLS) have been implemented to insure the accuracy of these measurements. We have calibrated vacuum x-ray diodes, mirrors and filters.

  7. Design and characterization of a pulsed x-ray source for fluorescent lifetime measurements

    SciTech Connect

    Blankespoor, S.C. |

    1993-12-01

    To search for new, fast, inorganic scintillators, the author and his colleagues have developed a bench-top pulsed x-ray source for determining fluorescent lifetimes and wavelengths of compounds in crystal or powdered form. This source uses a light-excited x-ray tube which produces x-rays when light from a laser diode strikes its photocathode. The x-ray tube has a tungsten anode, a beryllium exit window, a 30 kV maximum tube bias, and a 50 HA maximum average cathode current. The laser produces 3 {times} 10{sup 7} photons at 650 nm per {approximately}100 ps pulse, with up to 10{sup 7} pulses/sec. The time spread for the laser diode, x-ray tube, and a microchannel plate photomultiplier tube is less than 120 ps fwhm. The mean x-ray photon energy, at tube biases of 20, 25, and 30 kV, is 9.4, 10.3, and 11.1 keV, respectively. They measured 140, 230, and 330 x-ray photons per laser diode pulse per steradian at tube biases of 20, 25, and 30 kV, respectively. Background x-rays due to dark current occur at a rate of 1 {times} 10{sup 6} and 3 {times} 10{sup 6} photons/sec/steradian at tube biases of 25 and 30 kV, respectively. Data characterizing the x-ray output with an aluminum filter in the x-ray beam are also presented.

  8. RF photoinjector development for a short-pulse, hard x-ray Thomson scattering source

    NASA Astrophysics Data System (ADS)

    Le Sage, G. P.; Anderson, S. G.; Cowan, T. E.; Crane, J. K.; Ditmire, T.; Rosenzweig, J. B.

    2001-05-01

    An important motivation in the development of the next generation x-ray light sources is to achieve picosecond and sub-ps pulses of hard x-rays for dynamic studies of a variety of physical, chemical, and biological processes. Present hard x-ray sources are either pulse-width or intensity limited, which allows ps-scale temporal resolution only for signal averaging of highly repetitive processes. A much faster and brighter hard x-ray source is being developed at LLNL, based on Thomson scattering of fs-laser pulses by a relativistic electron beam, which will enable x-ray characterization of the transient structure of a sample in a single shot. Experimental and diagnostic techniques relevant to the development of next generation sources including the Linac Coherent Light Source can be tested with the Thomson scattering hard x-ray source. This source will combine an RF photoinjector with a 100 MeV S-band linac. The photoinjector and linac also provide an ideal test-bed for examining space-charge induced emittance growth effects. A program of beam dynamics and diagnostic experiments are planned in parallel with Thomson source development. Our experimental progress and future plans will be discussed.

  9. Prospects for using high power x-rays as a volumetric heat source

    SciTech Connect

    Rosenberg, R.A.; Farrell, W.; Ma, Q.

    1997-09-01

    Third-generation, high-intensity, x-ray synchrotron radiation sources are capable of producing high heat-flux x-ray beams. In many applications finding ways to handle these powers is viewed as a burden. However, there are some technological applications where the deep penetration length of the x-rays may find beneficial uses as a volumetric heat source. In this paper the authors discuss the prospects for using high power x-rays for volumetric heating and report some recent experimental results. The particular applications they focus on are welding and surface heat treatment. The radiation source is an undulator at the Advanced Photon Source (APS). Results of preliminary tests on aluminum, aluminum metal matrix composites, and steel will be presented.

  10. X-rays beware: the deepest Chandra catalogue of point sources in M31

    NASA Astrophysics Data System (ADS)

    Vulic, N.; Gallagher, S. C.; Barmby, P.

    2016-10-01

    This study represents the most sensitive Chandra X-ray point source catalogue of M31. Using 133 publicly available Chandra ACIS-I/S observations totalling ˜1 Ms, we detected 795 X-ray sources in the bulge, north-east, and south-west fields of M31, covering an area of ≈0.6 deg2, to a limiting unabsorbed 0.5-8.0 keV luminosity of ˜1034 erg s-1. In the inner bulge, where exposure is approximately constant, X-ray fluxes represent average values because they were determined from many observations over a long period of time. Similarly, our catalogue is more complete in the bulge fields since monitoring allowed more transient sources to be detected. The catalogue was cross-correlated with a previous XMM-Newton catalogue of M31's D25 isophote consisting of 1948 X-ray sources, with only 979 within the field of view of our survey. We found 387 (49 per cent) of our Chandra sources (352 or 44 per cent unique sources) matched to within 5 arcsec of 352 XMM-Newton sources. Combining this result with matching done to previous Chandra X-ray sources we detected 259. new sources in our catalogue. We created X-ray luminosity functions (XLFs) in the soft (0.5-2.0 keV) and hard (2.0-8.0 keV) bands that are the most sensitive for any large galaxy based on our detection limits. Completeness-corrected XLFs show a break around ≈1.3 × 1037 erg s-1, consistent with previous work. As in past surveys, we find that the bulge XLFs are flatter than the disc, indicating a lack of bright high-mass X-ray binaries in the disc and an aging population of low-mass X-ray binaries in the bulge.

  11. AN EVOLVING COMPACT JET IN THE BLACK HOLE X-RAY BINARY MAXI J1836-194

    SciTech Connect

    Russell, D. M.; Russell, T. D.; Miller-Jones, J. C. A.; Soria, R.; Slaven-Blair, T.; Curran, P. A.; O'Brien, K.; Sivakoff, G. R.; Lewis, F.; Markoff, S.; Altamirano, D.; Homan, J.; Rupen, M. P.; Dhawan, V.; Belloni, T. M.; Cadolle Bel, M.; Casella, P.; Corbel, S.; Gallo, E.; and others

    2013-05-10

    We report striking changes in the broadband spectrum of the compact jet of the black hole transient MAXI J1836-194 over state transitions during its discovery outburst in 2011. A fading of the optical-infrared (IR) flux occurred as the source entered the hard-intermediate state, followed by a brightening as it returned to the hard state. The optical-IR spectrum was consistent with a power law from optically thin synchrotron emission, except when the X-ray spectrum was softest. By fitting the radio to optical spectra with a broken power law, we constrain the frequency and flux of the optically thick/thin break in the jet synchrotron spectrum. The break gradually shifted to higher frequencies as the source hardened at X-ray energies, from {approx}10{sup 11} to {approx}4 Multiplication-Sign 10{sup 13} Hz. The radiative jet luminosity integrated over the spectrum appeared to be greatest when the source entered the hard state during the outburst decay (although this is dependent on the high-energy cooling break, which is not seen directly), even though the radio flux was fading at the time. The physical process responsible for suppressing and reactivating the jet (neither of which are instantaneous but occur on timescales of weeks) is uncertain, but could arise from the varying inner accretion disk radius regulating the fraction of accreting matter that is channeled into the jet. This provides an unprecedented insight into the connection between inflow and outflow, and has implications for the conditions required for jets to be produced, and hence their launching process.

  12. An Evolving Compact Jet in the Black Hole X-Ray Binary Maxi J1836-194

    NASA Technical Reports Server (NTRS)

    Russell, D. M.; Russell, T. D.; Miller-Jones, J. C. A.; O'Brien, K.; Soria, R.; Sivakoff, G. R.; Slaven-Blair, T.; Lewis, F.; Markoff, S.; Homan, J.; Altanirano, D.; Curran, P. A.; Rupen, M. P.; Belloni, T. M.; Cadolle Bel, M.; Casella, P.; Corbel, S.; Dhawan, V.; Fender, R. P.; Gallo, E.; Gandhi, P.; Heinz, S.; Koerding, E. G.; Krimm, H. A.; Maitra, D.

    2013-01-01

    We report striking changes in the broadband spectrum of the compact jet of the black hole transient MAXI J1836-194 over state transitions during its discovery outburst in 2011. A fading of the optical-infrared (IR) flux occurred as the source entered the hard-intermediate state, followed by a brightening as it returned to the hard state. The optical-IR spectrum was consistent with a power law from optically thin synchrotron emission, except when the X-ray spectrum was softest. By fitting the radio to optical spectra with a broken power law, we constrain the frequency and flux of the optically thick/thin break in the jet synchrotron spectrum. The break gradually shifted to higher frequencies as the source hardened at X-ray energies, from approx 10(exp 11) to approx 4 × 10(exp 13) Hz. The radiative jet luminosity integrated over the spectrum appeared to be greatest when the source entered the hard state during the outburst decay (although this is dependent on the high-energy cooling break, which is not seen directly), even though the radio flux was fading at the time. The physical process responsible for suppressing and reactivating the jet (neither of which are instantaneous but occur on timescales of weeks) is uncertain, but could arise from the varying inner accretion disk radius regulating the fraction of accreting matter that is channeled into the jet. This provides an unprecedented insight into the connection between inflow and outflow, and has implications for the conditions required for jets to be produced, and hence their launching process.

  13. 77 FR 12226 - Sadex Corp.; Filing of Food Additive Petition (Animal Use); Electron Beam and X-Ray Sources for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-29

    ... Petition (Animal Use); Electron Beam and X-Ray Sources for Irradiation of Poultry Feed and Poultry Feed... regulations be amended to provide for the safe use of electron beam and x-ray sources for irradiation of... use of electron beam and x- ray sources for irradiation of poultry feed and poultry feed...

  14. Long Duration Multi-hohlraum X-ray Sources for Eagle Nebula Laboratory Experiments

    NASA Astrophysics Data System (ADS)

    Kane, Jave; Heeter, Robert; Martinez, David; Casner, Alexis; Villette, Bruno; Mancini, Roberto; Pound, Marc

    2013-10-01

    A novel foam-filled multi-hohlraum long-duration x-ray source has been demonstrated at the Omega EP laser and used to obtain L-band spectra of photoionized Ti. A larger scale version of the source will be used in the Science on NIF Eagle Nebula experiments studying dynamic evolution of distinctive pillar and cometary structures in star-forming clouds, where the long duration and directionality of photoionizing radiation from nearby stars generates new classes of flows and instabilities. At NIF, a target representing an astrophysical molecular cloud will be placed several mm from an x-ray source lasting 40-100 ns. At EP, three hohlraums were illuminated in sequence with 3.3 kJ pulses lasting 6 ns, or 4.3 kJ pulses lasting 10 ns, generating 18 or 30 ns of x-ray output at 90-100 eV color temperature. Performance of the source was validated using the μ DMX and VSG spectrometers, ASBO VISAR, and x-ray pinhole imagery. The HYDRA code suggests the EP-scale source can also be shot at NIF with at least 10 kJ per hohlraum. The multi-hohlraum source concept has potential further application to hard x-ray sources, soft x-ray backlighters, and nonlinear ablative hydrodynamics. Prepared by LLNL under Contract DE-AC52-07NA27344. J. Kane supported by DOE OFES grant HEDLP LAB 11-583.

  15. Integration of a broad beam ion source with a high-temperature x-ray diffraction vacuum chamber

    NASA Astrophysics Data System (ADS)

    Manova, D.; Bergmann, A.; Mändl, S.; Neumann, H.; Rauschenbach, B.

    2012-11-01

    Here, the integration of a low energy, linearly variable ion beam current density, mechanically in situ adjustable broad beam ion source with a high-temperature x-ray diffraction (XRD) vacuum chamber is reported. This allows in situ XRD investigation of phase formation and evolution processes induced by low energy ion implantation. Special care has been taken to an independent adjustment of the ion beam for geometrical directing towards the substrate, a 15 mm small ion source exit aperture to avoid a secondary sputter process of the chamber walls, linearly variable ion current density by using a pulse length modulation (PLM) for the accelerating voltages without changing the ion beam density profile, nearly homogeneous ion beam distribution over the x-ray footprint, together with easily replaceable Kapton® windows for x-rays entry and exit. By combining a position sensitive x-ray detector with this PLM-modulated ion beam, a fast and efficient time resolved investigation of low energy implantation processes is obtained in a compact experimental setup.

  16. Integration of a broad beam ion source with a high-temperature x-ray diffraction vacuum chamber

    SciTech Connect

    Manova, D.; Bergmann, A.; Maendl, S.; Neumann, H.; Rauschenbach, B.

    2012-11-15

    Here, the integration of a low energy, linearly variable ion beam current density, mechanically in situ adjustable broad beam ion source with a high-temperature x-ray diffraction (XRD) vacuum chamber is reported. This allows in situ XRD investigation of phase formation and evolution processes induced by low energy ion implantation. Special care has been taken to an independent adjustment of the ion beam for geometrical directing towards the substrate, a 15 mm small ion source exit aperture to avoid a secondary sputter process of the chamber walls, linearly variable ion current density by using a pulse length modulation (PLM) for the accelerating voltages without changing the ion beam density profile, nearly homogeneous ion beam distribution over the x-ray footprint, together with easily replaceable Kapton{sup Registered-Sign} windows for x-rays entry and exit. By combining a position sensitive x-ray detector with this PLM-modulated ion beam, a fast and efficient time resolved investigation of low energy implantation processes is obtained in a compact experimental setup.

  17. New Directions in X-Ray Light Sources or Fiat Lux: what's under the dome and watching atoms with x-rays (LBNL Summer Lecture Series)

    SciTech Connect

    Falcone, Roger

    2008-07-15

    Summer Lecture Series 2008: 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. New Directions in X-Ray Light Sources or Fiat Lux: what's under the dome and watching atoms with x-rays (LBNL Summer Lecture Series)

    ScienceCinema

    Falcone, Roger

    2016-07-12

    Summer Lecture Series 2008: 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.

  19. Convertible source system of thermal neutron and X-ray at Hokkaido University electron linac facility

    NASA Astrophysics Data System (ADS)

    Kamiyama, T.; Hara, K. Y.; Taira, H.; Sato, H.

    2016-11-01

    The convertible source system for the neutron and the X-ray imagings was installed in the 45MeV electron linear accelerator facility at Hokkaido University. The source system is very useful for a complementary imaging. The imaging measurements for a sample were performed with both beams by using a vacuum tube type image intensifier. The enhanced contrast was obtained from the dataset of the radiograms measured with the neutron and X-ray beams.

  20. Quasiperiodic oscillations in bright galactic-bulge X-ray sources

    NASA Technical Reports Server (NTRS)

    Lamb, F. K.; Shibazaki, N.; Alpar, M. A.; Shaham, J.

    1985-01-01

    Quasiperiodic oscillations with frequencies in the range 5-50 Hz have recently been discovered in X-rays from two bright galactic-bulge sources and Sco X-1. These sources are weakly magnetic neutron stars accreting from disks which the plasma is clumped. The interaction of the magnetosphere with clumps in the inner disk causes oscillations in the X-ray flux with many of the properties observed.

  1. Transient X-Ray Source Population in the Magellanic-type Galaxy NGC 55

    NASA Astrophysics Data System (ADS)

    Jithesh, V.; Wang, Zhongxiang

    2016-04-01

    We present the spectral and temporal properties of 15 candidate transient X-ray sources detected in archival XMM-Newton and Chandra observations of the nearby Magellanic-type, SB(s)m galaxy NGC 55. Based on an X-ray color classification scheme, the majority of the sources may be identified as X-ray binaries (XRBs), and six sources are soft, including a likely supernova remnant. We perform a detailed spectral and variability analysis of the data for two bright candidate XRBs. Both sources displayed strong short-term X-ray variability, and their X-ray spectra and hardness ratios are consistent with those of XRBs. These results, combined with their high X-ray luminosities (˜1038 erg s-1), strongly suggest that they are black hole (BH) binaries. Seven less luminous sources have spectral properties consistent with those of neutron star or BH XRBs in both normal and high-rate accretion modes, but one of them is the likely counterpart to a background galaxy (because of positional coincidence). From our spectral analysis, we find that the six soft sources are candidate super soft sources (SSSs) with dominant emission in the soft (0.3-2 keV) X-ray band. Archival Hubble Space Telescope optical images for seven sources are available, and the data suggest that most of them are likely to be high-mass XRBs. Our analysis has revealed the heterogeneous nature of the transient population in NGC 55 (six high-mass XRBs, one low-mass XRBs, six SSSs, one active galactic nucleus), helping establish the similarity of the X-ray properties of this galaxy to those of other Magellanic-type galaxies.

  2. Optical synchronization system for femtosecond X-ray sources

    DOEpatents

    Wilcox, Russell B.; Holzwarth, Ronald

    2011-12-13

    Femtosecond pump/probe experiments using short X-Ray and optical pulses require precise synchronization between 100 meter-10 km separated lasers in a various experiments. For stabilization in the hundred femtosecond range a CW laser is amplitude modulated at 1-10 GHz, the signal retroreflected from the far end, and the relative phase used to correct the transit time with various implementations. For the sub-10 fsec range the laser frequency itself is upshifted 55 MHz with an acousto-optical modulator, retroreflected, upshifted again and phase compared at the sending end to a 110 MHz reference. Initial experiments indicate less than 1 fsec timing jitter. To lock lasers in the sub-10 fs range two single-frequency lasers separated by several teraHertz will be lock to a master modelocked fiber laser, transmit the two frequencies over fiber, and lock two comb lines of a slave laser to these frequencies, thus synchronizing the two modelocked laser envelopes.

  3. [Experimental investigation of laser plasma soft X-ray source with gas target].

    PubMed

    Ni, Qi-liang; Gong, Yan; Lin, Jing-quan; Chen, Bo; Cao, Jian-lin

    2003-02-01

    This paper describes a debris-free laser plasma soft X-ray source with a gas target, which has high operating frequency and can produce strong soft X-ray radiation. The valve of this light source is drived by a piezoelectrical ceramic whose operating frequency is up to 400 Hz. In comparison with laser plasma soft X-ray sources using metal target, the light source is debris-free. And it has higher operating frequency than gas target soft X-ray sources whose nozzle is controlled by a solenoid valve. A channel electron multiplier (CEM) operating in analog mode is used to detect the soft X-ray generated by the laser plasma source, and the CEM's output is fed to to a charge-sensitive preamplifier for further amplification purpose. Output charges from the CEM are proportional to the amplitude of the preamplifier's output voltage. Spectra of CO2, Xe and Kr at 8-14 nm wavelength which can be used for soft X-ray projection lithography are measured. The spectrum for CO2 consists of separate spectral lines originate mainly from the transitions in Li-like and Be-like ions. The Xe spectrum originating mainly from 4d-5f, 4d-4f, 4d-6p and 4d-5p transitions in multiply charged xenon ions. The spectrum for Kr consists of separate spectral lines and continuous broad spectra originating mainly from the transitions in Cu-, Ni-, Co- and Fe-like ions.

  4. The luminosity function of galactic X-ray sources - A cutoff and a 'standard candle'

    NASA Technical Reports Server (NTRS)

    Margon, B.; Ostriker, J. P.

    1973-01-01

    Analysis of the 2- to 10-kev luminosity distribution of 36 X-ray sources in the Local Group having known or estimated distances, showing that there exists a luminosity cutoff of approximately 10 to the 37.7th ergs/sec in agreement with the theoretical (Eddington) limit for the luminosity of an approximately 1 solar mass star. Furthermore, among the complete sample of high-luminosity sources, there appears to be a statistically significant group of X-ray 'standard candles' at (within less than 0.8 mag) the critical luminosity. This finding (which is in agreement with the self-consistent mass flow accretion models) presents the possibility that X-ray sources may be used as extragalactic distance indicators in the next generation of X-ray astronomy experiments.

  5. A carbon nanotube field emission multipixel x-ray array source for microradiotherapy application

    PubMed Central

    Wang, Sigen; Calderon, Xiomara; Peng, Rui; Schreiber, Eric C.; Zhou, Otto; Chang, Sha

    2011-01-01

    The authors report a carbon nanotube (CNT) field emission multipixel x-ray array source for microradiotherapy for cancer research. The developed multipixel x-ray array source has 50 individually controllable pixels and it has several distinct advantages over other irradiation source including high-temporal resolution (millisecond level), the ability to electronically shape the form, and intensity distribution of the radiation fields. The x-ray array was generated by a CNT cathode array (5×10) chip with electron field emission. A dose rate on the order of >1.2 Gy∕min per x-ray pixel beam is achieved at the center of the irradiated volume. The measured dose rate is in good agreement with the Monte Carlo simulation result. PMID:21691440

  6. A carbon nanotube field emission multipixel x-ray array source for microradiotherapy application

    SciTech Connect

    Wang Sigen; Calderon, Xiomara; Peng Rui; Schreiber, Eric C.; Zhou, Otto; Chang, Sha

    2011-05-23

    The authors report a carbon nanotube (CNT) field emission multipixel x-ray array source for microradiotherapy for cancer research. The developed multipixel x-ray array source has 50 individually controllable pixels and it has several distinct advantages over other irradiation source including high-temporal resolution (millisecond level), the ability to electronically shape the form, and intensity distribution of the radiation fields. The x-ray array was generated by a CNT cathode array (5x10) chip with electron field emission. A dose rate on the order of >1.2 Gy/min per x-ray pixel beam is achieved at the center of the irradiated volume. The measured dose rate is in good agreement with the Monte Carlo simulation result.

  7. Miniature, low-power X-ray tube using a microchannel electron generator electron source

    NASA Technical Reports Server (NTRS)

    Elam, Wm. Timothy (Inventor); Kelliher, Warren C. (Inventor); Hershyn, William (Inventor); DeLong, David P. (Inventor)

    2011-01-01

    Embodiments of the invention provide a novel, low-power X-ray tube and X-ray generating system. Embodiments of the invention use a multichannel electron generator as the electron source, thereby increasing reliability and decreasing power consumption of the X-ray tube. Unlike tubes using a conventional filament that must be heated by a current power source, embodiments of the invention require only a voltage power source, use very little current, and have no cooling requirements. The microchannel electron generator comprises one or more microchannel plates (MCPs), Each MCP comprises a honeycomb assembly of a plurality of annular components, which may be stacked to increase electron intensity. The multichannel electron generator used enables directional control of electron flow. In addition, the multichannel electron generator used is more robust than conventional filaments, making the resulting X-ray tube very shock and vibration resistant.

  8. X-Ray Absorption Toward the Einstein Ring Source PKS 1830-211

    NASA Technical Reports Server (NTRS)

    Mathur, Smita; Nair, Sunita

    1997-01-01

    PKS 1830-211 is an unusually radio-loud gravitationally lensed quasar. In the radio spectrum, the system appears as two compact, dominant features surrounded by relatively extended radio emission that forms an Einstein ring. As the line of sight to it passes close to our Galactic center, PKS 1830-211 has not been detected in wave bands other than the radio and X-ray so far. Here we present X-ray data of PKS 1830-211 observed with ROSAT Position Sensitive Proportional Counter. The X-ray spectrum shows that absorption in excess of the Galactic contribution is highly likely, which at the redshift of the lensing galaxy (z(sub t)=0.886) corresponds to N(sub H)=3.5((sup 0.6)(sub -0.5))x10(exp 22) atoms sq cm. The effective optical extinction is large, A(sub V)(observed) is greater than or approximately 5.8. When corrected for this additional extinction, the two-point optical to X-ray slope alpha(sub ox) of PKS 1830-211 lies just within the observed range of quasars. It is argued here that both compact images must be covered by the X-ray absorber(s) that we infer to be the lensing galaxy (galaxies). The dust-to-gas ratio along the line of sight within the lensing galaxy is likely to be somewhat larger than for our Galaxy.

  9. Exploring the overabundance of ultraluminous X-ray sources in metal- and dust-poor local Lyman break analogs

    NASA Astrophysics Data System (ADS)

    Basu-Zych, Antara; Lehmer, Bret; Fragos, Tassos; Hornschemeier, Ann E.; Zezas, Andreas; Yukita, Mihoko; Ptak, Andrew

    2016-01-01

    We have studied high mass X-ray binary (HMXB) populations within two low-metallicity, starburst galaxies, Haro 11 and VV 114. These galaxies serve as analogs to high-redshift (z > 2) Lyman break galaxies, and within the larger sample of Lyman break analogs (LBAs) are sufficiently nearby (< 87 Mpc) to be spatially-resolved by Chandra. Previous studies of the X-ray emission in LBAs have found that the 2-10 keV luminosity per star formation rate (SFR) in these galaxies is elevated, potentially because of their low metallicities (12+log[O/H]=8.3-8.4). Theoretically, the progenitors of XRBs forming in lower metallicity environments lose less mass from stellar winds over their lifetimes, producing more massive compact objects (i.e., neutron stars and black holes), and thus resulting in more numerous and luminous HMXBs per SFR. In this talk, I present our in-depth study of the only two LBAs that have spatially-resolved 2-10 keV emission with Chandra to present the bright end of the X-ray luminosity distribution of HMXBs (LX>1039 erg s-1 ultraluminous X-ray sources, ULXs) in these low-metallicity galaxies, based on 8 detected ULXs. Comparing with the star-forming galaxy X-ray luminosity function (XLF), Haro 11 and VV 114 host ~4 times more LX>1040 erg s-1 sources than expected given their SFRs. We simulate the effects of source blending from crowded lower luminosity HMXBs using the star-forming galaxy XLF and then vary the XLF normalizations and bright-end slopes until we reproduce the observed point source luminosity distributions. Based on this analysis, we find that these LBAs have a shallower bright end slope than the standard XLF.

  10. A Multi-Wavelength Study of the X-Ray Sources in the NGC 5018

    NASA Technical Reports Server (NTRS)

    Ghosh, Kajal K.; Swartz, Douglas A.; Tennant, Allyn F.; Wu, Kinwah; Saripalli, Lakshmi

    2004-01-01

    The E3 giant elliptical galaxy NGC-5018 was observed with the cxo X-ray Observatory's Advanced CCD Imaging Spectrometer for 30-h on 14 April 2001. Results of analysis of these X-ray data as well as of complementary optical, infrared, and radio data are reported. Seven X-ray point sources, including the nucleus, were detected. If they are intrinsic to NGC-5018, then all six non-nuclear sources have luminosities exceeding 10(exp 39)-ergl in the 0.5-8.0-keV energy band; placing them in the class of Ultra- luminous X-ray sources. Comparison of X-ray source positions to archival Hubble Space Telescope/Wide Field Planetary Camera 2 (hst/WFPC2) images reveal four of the six non-nuclear sources are spatially--coincident with bright, M$(sub V)LA -8.6 mag, objects. These four objects have optical magnitudes and (V-I) colors consistent with globular clusters in NGC-5018. However, one of these objects was observed to vary by siml mag in both V and I between observations taken 28 July 1997 and 04 Feb 1999 indicating this source is a background active galactic nucleus (AGN). The nature of the other three optically-bright objects cannot be determined from the available optical data but all have X-ray-to-optical flux ratios consistent with background AGNs. Strong, unpolarized, radio emission has been detected from another of the optically-bright counterparts. It displays an inverted radio spectrum and is the most absorbed of the seven sources in the X-ray band. It, too, is most readily explained as a background AGN, though alternative explanations cannot be ruled out. Extended X-ray emission is detected within a siml5 arcsec radius of the galaxy center at a luminosity of sim lO(exp 40)-ergl in the X-ray band. Its thermal X-ray spectrum (kT sim0.4-keV) and its spatial coincidence with strong H(alpha) emission are consistent with a hot gas origin. The nucleus itself is a weak X-ray source, LA-5 times 10(exp 39)-ergl, but displays a radio spectrum typical of AGN.

  11. Evidence for the binary nature of A0535+26. [SAS-3 observation of transient X ray source

    NASA Technical Reports Server (NTRS)

    Rappaport, S.; Bradt, H.; Clark, G. W.; Jernigan, J. G.; Joss, P. C.

    1976-01-01

    The transient X-ray source A0535+26 was observed extensively with the SAS-3 satellite on two occasions. Sufficient timing data on the 104-s periodicity were obtained to indicate that the pulse period was changing during both of the observations. The possibility that these period changes are intrinsic to the compact star (e.g., due to accretion torques) cannot be completely excluded. However, it is demonstrated that all of the SAS-3 timing data can be explained by orbital motion of the X-ray star about a companion. Constraints are then placed on the orbital elements of the system. The results indicate a model for this source that consists of a neutron star in a long-period orbit (period of at least 17 days) about an OB star with a variable stellar wind.

  12. The soft x-ray instrument for materials studies at the linac coherent light source x-ray free-electron laser

    SciTech Connect

    Schlotter, W. F.; Turner, J. J.; Rowen, M.; Holmes, M.; Messerschmidt, M.; Moeller, S.; Krzywinski, J.; Lee, S.; Coffee, R.; Hays, G.; Heimann, P.; Krupin, O.; Soufli, R.; Fernandez-Perea, M.; Hau-Riege, S.; Kelez, N.; Beye, M.; Gerken, N.; Sorgenfrei, F.; Wurth, W.; and others

    2012-04-15

    The soft x-ray materials science instrument is the second operational beamline at the linac coherent light source x-ray free electron laser. The instrument operates with a photon energy range of 480-2000 eV and features a grating monochromator as well as bendable refocusing mirrors. A broad range of experimental stations may be installed to study diverse scientific topics such as: ultrafast chemistry, surface science, highly correlated electron systems, matter under extreme conditions, and laboratory astrophysics. Preliminary commissioning results are presented including the first soft x-ray single-shot energy spectrum from a free electron laser.

  13. X-ray sources and high-throughput data collection methods.

    PubMed

    Snell, Gyorgy

    2012-01-01

    X-ray diffraction experiments on protein crystals are at the core of the structure determination process. An overview of X-ray sources and data collection methods to support structure-based drug design (SBDD) efforts is presented in this chapter. First, methods of generating and manipulating X-rays for the purpose of protein crystallography, as well as the components of the diffraction experiment setup are discussed. SBDD requires the determination of numerous protein-ligand complex structures in a timely manner, and the second part of this chapter describes how to perform diffraction experiments efficiently on a large number of crystals, including crystal screening and data collection.

  14. Symbiotic Stars in X-rays. II. Faint Sources Detected with XMM-Newton and Chandra

    NASA Technical Reports Server (NTRS)

    Nunez, N. E.; Luna, G. J. M.; Pillitteri, I.; Mukai, K.

    2014-01-01

    We report the detection from four symbiotic stars that were not known to be X-ray sources. These four object show a ß-type X-ray spectrum, that is, their spectra can be modeled with an absorbed optically thin thermal emission with temperatures of a few million degrees. Photometric series obtained with the Optical Monitor on board XMM-Newton from V2416 Sgr and NSV 25735 support the proposed scenario where the X-ray emission is produced in a shock-heated region inside the symbiotic nebulae.

  15. Calibration of a time-resolved hard-x-ray detector using radioactive sources

    NASA Astrophysics Data System (ADS)

    Stoeckl, C.; Theobald, W.; Regan, S. P.; Romanofsky, M. H.

    2016-11-01

    A four-channel, time-resolved, hard x-ray detector (HXRD) has been operating at the Laboratory for Laser Energetics for more than a decade. The slope temperature of the hot-electron population in direct-drive inertial confinement fusion experiments is inferred by recording the hard x-ray radiation generated in the interaction of the electrons with the target. Measuring the energy deposited by hot electrons requires an absolute calibration of the hard x-ray detector. A novel method to obtain an absolute calibration of the HXRD using single photons from radioactive sources was developed, which uses a thermoelectrically cooled, low-noise, charge-sensitive amplifier.

  16. X-Ray Sources and High-Throughput Data Collection Methods

    SciTech Connect

    Snell, Gyorgy

    2012-03-15

    X-ray diffraction experiments on protein crystals are at the core of the structure determination process. An overview of X-ray sources and data collection methods to support structure-based drug design (SBDD) efforts is presented in this chapter. First, methods of generating and manipulating X-rays for the purpose of protein crystallography, as well as the components of the diffraction experiment setup are discussed. SBDD requires the determination of numerous protein-ligand complex structures in a timely manner, and the second part of this chapter describes how to perform diffraction experiments efficiently on a large number of crystals, including crystal screening and data collection.

  17. X-ray microtomography study of the compaction process of rods under tapping

    NASA Astrophysics Data System (ADS)

    Fu, Yang; Xi, Yan; Cao, Yixin; Wang, Yujie

    2012-05-01

    We present an x-ray microtomography study of the compaction process of cylindrical rods under tapping. The process is monitored by measuring the evolution of the orientational order parameter, local, and overall packing densities as a function of the tapping number for different tapping intensities. The slow relaxation dynamics of the orientational order parameter can be well fitted with a stretched-exponential law with stretching exponents ranging from 0.9 to 1.6. The corresponding relaxation time versus tapping intensity follows an Arrhenius behavior which is reminiscent of the slow dynamics in thermal glassy systems. We also investigated the boundary effect on the ordering process and found that boundary rods order faster than interior ones. In searching for the underlying mechanism of the slow dynamics, we estimated the initial random velocities of the rods under tapping and found that the ordering process is compatible with a diffusion mechanism. The average coordination number as a function of the tapping number at different tapping intensities has also been measured, which spans a range from 6 to 8.

  18. Chandra Resolves Cosmic X-ray Glow and Finds Mysterious New Sources

    NASA Astrophysics Data System (ADS)

    2000-01-01

    While taking a giant leap towards solving one of the greatest mysteries of X-ray astronomy, NASA's Chandra X-ray Observatory also may have revealed the most distant objects ever seen in the universe and discovered two puzzling new types of cosmic objects. Not bad for being on the job only five months. Chandra has resolved most of the X-ray background, a pervasive glow of X-rays throughout the universe, first discovered in the early days of space exploration. Before now, scientists have not been able to discern the background's origin, because no X-ray telescope until Chandra has had both the angular resolution and sensitivity to resolve it. "This is a major discovery," said Dr. Alan Bunner, Director of NASA's Structure andEvolution of the universe science theme. "Since it was first observed thirty-seven years ago, understanding the source of the X-ray background has been aHoly Grail of X-ray astronomy. Now, it is within reach." The results of the observation will be discussed today at the 195th national meeting of the American Astronomical Society in Atlanta, Georgia. An article describing this work has been submitted to the journal Nature by Dr. Richard Mushotzky, of NASA Goddard Space Flight Center, Greenbelt, Md., Drs. Lennox Cowie and Amy Barger at the University of Hawaii, Honolulu, and Dr. Keith Arnaud of the University of Maryland, College Park. "We are all very excited by this finding," said Mushotzky. "The resolution of most of the hard X-ray background during the first few months of the Chandra mission is a tribute to the power of this observatory and bodes extremely well for its scientific future," Scientists have known about the X-ray glow, called the X-ray background, since the dawn of X-ray astronomy in the early 1960s. They have been unable to discern its origin, however, for no X-ray telescope until Chandra has had both the angular resolution and sensitivity to resolve it. The German-led ROSAT mission, now completed, resolved much of the lower

  19. Derivation of total filtration thickness for diagnostic x-ray source assembly

    NASA Astrophysics Data System (ADS)

    Sekimoto, Michiharu; Katoh, Yoh

    2016-08-01

    The method defined by the IEC 60522 for determining the inherent filtration of an x-ray source device is applicable only for a limited range of tube voltage. Because the users cannot legally remove the x-ray movable diaphragm of the x-ray source device, total filtration, which is the sum of the additional filtration diaphragm movable for specific filtration and x-ray, cannot be measured. We develop a method for simply obtaining the total filtration for different tube voltage values. Total filtration can be estimated from a ratio R‧ of the air kerma Kx+T\\prime , which is measured with an Al plate with thickness T, and Kx\\prime measured without an Al plate. The conditions of the target material of the x-ray source device are then entered into the Report 78 Spectrum Processor to calculate the air kerma K x and K x+T for Al thicknesses x and (x  +  T), respectively, to obtain R. The minimum value of x, which is the difference between the R and R‧, is the total filtration of the x-ray source device. The total filtration calculated using the industrial x-ray source device was within  ±1% in the 40–120 kV range. This method can calculate the total filtration using air kerma measurements with and without the Al plate. Therefore, the load on the x-ray tube can be reduced, and preparation of multiple Al plates is not necessary. Furthermore, for the 40–120 kV tube voltage range, the user can easily measure the total filtration.

  20. Derivation of total filtration thickness for diagnostic x-ray source assembly.

    PubMed

    Sekimoto, Michiharu; Katoh, Yoh

    2016-08-21

    The method defined by the IEC 60522 for determining the inherent filtration of an x-ray source device is applicable only for a limited range of tube voltage. Because the users cannot legally remove the x-ray movable diaphragm of the x-ray source device, total filtration, which is the sum of the additional filtration diaphragm movable for specific filtration and x-ray, cannot be measured. We develop a method for simply obtaining the total filtration for different tube voltage values. Total filtration can be estimated from a ratio R' of the air kerma [Formula: see text], which is measured with an Al plate with thickness T, and [Formula: see text] measured without an Al plate. The conditions of the target material of the x-ray source device are then entered into the Report 78 Spectrum Processor to calculate the air kerma K x and K x+T for Al thicknesses x and (x  +  T), respectively, to obtain R. The minimum value of x, which is the difference between the R and R', is the total filtration of the x-ray source device. The total filtration calculated using the industrial x-ray source device was within  ±1% in the 40-120 kV range. This method can calculate the total filtration using air kerma measurements with and without the Al plate. Therefore, the load on the x-ray tube can be reduced, and preparation of multiple Al plates is not necessary. Furthermore, for the 40-120 kV tube voltage range, the user can easily measure the total filtration.

  1. Impulsive and gradual hard X-ray sources in a solar flare

    NASA Technical Reports Server (NTRS)

    Vilmer, N.; Trotter, G.; Kane, S. R.

    1982-01-01

    The paper reports recent observations of a relatively large hard X-ray burst with well developed impulsive and gradual components, that was associated with a relatively modest optical flare on Aug. 14, 1979. The impulsive X-ray source has a much higher ion density and the electron injection in the phase is shorter in duration consisting of fewer energetic electrons than in the gradual phase. The gradual X-ray source seems to consist of a lower density region, probably bounded by a magnetic arch in which the energetic electrons are perfectly trapped. The different temporal development of the impulsive and gradual hard X-ray components suggest large differences in the physical parameters of the ambient plasma.

  2. X-ray sources in regions of star formation. I - The naked T Tauri stars

    NASA Technical Reports Server (NTRS)

    Walter, F. M.

    1986-01-01

    Einstein X-ray observations of regions of active star formation in Taurus, Ophiuchus, and Corona Australis show a greatly enhanced surface density of stellar X-ray sources over that seen in other parts of the sky. Many of the X-ray sources are identified with low-mass, pre-main-sequence stars which are not classical T Tauri stars. The X-ray, photometric, and spectroscopic data for these stars are discussed. Seven early K stars in Oph and CrA are likely to be 1-solar-mass post-T Tauri stars with ages of 10-million yr. The late K stars in Taurus are not post-T Tauri, but 'naked' T Tauri stars, which are coeval with the T Tauri stars, differing mainly in the lack of a circumstellar envelope.

  3. Beyond crystallography: Diffractive imaging using coherent x-ray light sources

    NASA Astrophysics Data System (ADS)

    Miao, Jianwei; Ishikawa, Tetsuya; Robinson, Ian K.; Murnane, Margaret M.

    2015-05-01

    X-ray crystallography has been central to the development of many fields of science over the past century. It has now matured to a point that as long as good-quality crystals are available, their atomic structure can be routinely determined in three dimensions. However, many samples in physics, chemistry, materials science, nanoscience, geology, and biology are noncrystalline, and thus their three-dimensional structures are not accessible by traditional x-ray crystallography. Overcoming this hurdle has required the development of new coherent imaging methods to harness new coherent x-ray light sources. Here we review the revolutionary advances that are transforming x-ray sources and imaging in the 21st century.

  4. Laboratory source based full-field x-ray microscopy at 9 keV

    NASA Astrophysics Data System (ADS)

    Fella, C.; Balles, A.; Wiest, W.; Zabler, S.; Hanke, R.

    2016-01-01

    In the past decade, hard x-ray transmission microscopy experienced tremendous developments. With the avail-ability of efficient Fresnel zone plates, even set-ups utilizing laboratory sources were developed [1]. In order to improve the performance of these x-ray microscopes, novel approaches to fabricate optical elements [2] and brighter x-ray tubes [3] are promising candidates. We are currently building a laboratory transmission x-ray microscope for 9.25 keV, using an electron impact liquid-metal-jet anode source. Up to now, the further elements of our setup are: a polycapillary condenser, a tungsten zone plate, and a scintillator which is optically coupled to a CMOS camera. However, further variations in terms of optical elements are intended. Here we present the current status of our work, as well as first experimental results.

  5. Persistent X-ray emission from a gamma-ray burst source

    NASA Technical Reports Server (NTRS)

    Grindlay, J. E.; Cline, T.; Desai, U. D.; Teegarden, B. J.; Pizzichini, G.; Evans, W. D.; Laros, J. G.; Hurley, K. C.; Niel, M.; Klebesadel, R. W.

    1982-01-01

    A quiescent X-ray source detected with the Einstein X-ray Observatory in a location consistent with that of an intense gamma ray burst is shown to be also consistent with the location of the 1928 optical transient, the likely optical counterpart of the gamma ray burst source GBS0117-29. The system appears to be underluminous in X-rays by a factor of 10; possible reasons for this are discussed. The observed X-ray flux would require an accretion rate of about 10 to the -14th (d/1 kpc/)-squared solar masses per year, which is probably too low to be consistent with published nuclear flash models for gamma bursts, unless the distance is substantially greater than about 1 kpc or the burst recurrence time is greater than about 50 yrs, or the accretion rate is highly variable. Such a long recurrence time appears to be inconsistent with the detection of the optical burst.

  6. Fourth-generation X-ray sources: some possible applications to biology.

    PubMed

    Doniach, S

    2000-05-01

    The term 'fourth generation X-ray sources' has come to mean X-ray free-electron lasers which use multi-GeV electron beams from linear accelerators to generate X-rays by self-amplified stimulated emission when fired into long undulators. Properties of the radiation expected from such sources are reviewed briefly and two possible applications of the resulting pulsed highly collimated X-radiation to problems in biology are discussed: use of X-ray photon correlation spectroscopy to measure time correlations of atoms in protein crystals, and use of Mössbauer radiation extracted from the photon beams by resonant Bragg diffraction from (57)Fe-containing crystals, for MAD phasing of very large unit-cell biomolecular crystals and possibly for photon echo measurements.

  7. X-ray phase contrast tomography with a bending magnet source

    NASA Astrophysics Data System (ADS)

    Peele, A. G.; De Carlo, F.; McMahon, P. J.; Dhal, B. B.; Nugent, K. A.

    2005-08-01

    X-ray radiography and x-ray tomography are important tools for noninvasive characterization of materials. Historically, the contrast mechanism used with these techniques has been absorption. However, for any given sample there are x-ray energies for which absorption contrast is poor. Alternatively, when good contrast can be obtained, radiation damage from an excessive dose may become an issue. Consequently, phase-contrast methods have in recent years been implemented at both synchrotron and laboratory facilities. A range of radiographic and tomographic demonstrations have now been made, typically utilizing the coherent flux from an insertion device at a synchrotron or a microfocus laboratory source. In this paper we demonstrate that useful results may be obtained using a bending magnet source at a synchrotron. In particular we show that the same beamline can be used to make and characterize a sample made by x-ray lithographic methods.

  8. Ultrafast Materials Probing with the LLNL Thomson X-Ray Source

    SciTech Connect

    Springer, P; Anderson, S; Brown, W; Barty, C; Cauble, R; Crane, J; Cynn, H; Ebbers, C; Fittinghoff, D; Gibson, D; Hartemann, F; Javanovich, I; Kuba, J; LeSage, G; McMahan, A; Minich, R; Moriarty, J; Remington, B; Slaughter, D; Steitz, F H; Tremaine, A; Yoo, C-s; Rosenzweig, J; Ditmire, T

    2002-09-03

    The use of short laser pulses to generate very high brightness, ultra short (fs to ps) x-ray pulses is a topic of great interest. In principle, fantosecond-scale pump-probe experiments can be used to temporally resolve structural dynamics of materials on the time scale of atomic motion. The development of sub-ps x-ray pulses will make possible a wide range of materials and plasma physics studies with unprecedented time resolution. The Thomson scattering project at LLNL will provide such a novel x-ray source of high power using short laser pulses and a high brightness, relativistic electron bunch. The system is based on a 5mm-mrad normalized emittance photoinjector, 100 MeV electron RF linac, and a 300 mJ, 35 fs solid-state laser system. The Thomson source will produce ultra fast pulses with x-ray energies (60 kev) capable of probing into high-Z metals.

  9. Beyond crystallography: diffractive imaging using coherent x-ray light sources.

    PubMed

    Miao, Jianwei; Ishikawa, Tetsuya; Robinson, Ian K; Murnane, Margaret M

    2015-05-01

    X-ray crystallography has been central to the development of many fields of science over the past century. It has now matured to a point that as long as good-quality crystals are available, their atomic structure can be routinely determined in three dimensions. However, many samples in physics, chemistry, materials science, nanoscience, geology, and biology are noncrystalline, and thus their three-dimensional structures are not accessible by traditional x-ray crystallography. Overcoming this hurdle has required the development of new coherent imaging methods to harness new coherent x-ray light sources. Here we review the revolutionary advances that are transforming x-ray sources and imaging in the 21st century.

  10. Beyond crystallography: Diffractive imaging using coherent x-ray light sources

    SciTech Connect

    Miao, J.; Ishikawa, T.; Robinson, I. K.; Murnane, M. M.

    2015-04-30

    X-ray crystallography has been central to the development of many fields of science over the past century. It has now matured to a point that as long as good-quality crystals are available, their atomic structure can be routinely determined in three dimensions. However, many samples in physics, chemistry, materials science, nanoscience, geology, and biology are noncrystalline, and thus their three-dimensional structures are not accessible by traditional x-ray crystallography. Overcoming this hurdle has required the development of new coherent imaging methods to harness new coherent x-ray light sources. Here we review the revolutionary advances that are transforming x-ray sources and imaging in the 21st century.

  11. Time-resolved materials science opportunities using synchrotron x-ray sources

    SciTech Connect

    Larson, B.C.; Tischler, J.Z.

    1995-06-01

    The high brightness, high intensity, and pulsed time-structure of synchrotron sources provide new opportunities for time-resolved x-ray diffraction investigations. With third generation synchrotron sources coming on line, high brilliance and high brightness are now available in x-ray beams with the highest flux. In addition to the high average flux, the instantaneous flux available in synchrotron beams is greatly enhanced by the pulsed time structure, which consists of short bursts of x-rays that are separated by {approximately}tens to hundreds of nanoseconds. Time-resolved one- and two-dimensional position sensitive detection techniques that take advantage of synchrotron radiation for materials science x-ray diffraction investigations are presented, and time resolved materials science applications are discussed in terms of recent diffraction and spectroscopy results and materials research opportunities.

  12. Quantitative phase retrieval with picosecond X-ray pulses from the ATF Inverse Compton Scattering source

    SciTech Connect

    Endrizzi, M.; Pogorelsky, I.; Gureyev, T.E.; Delogu, P.; Oliva, P.; Golosio, B.; Carpinelli, M.; Yakimenko, Y.; Bottigli, U.

    2011-01-28

    Quantitative phase retrieval is experimentally demonstrated using the Inverse Compton Scattering X-ray source available at the Accelerator Test Facility (ATF) in the Brookhaven National Laboratory. Phase-contrast images are collected using in-line geometry, with a single X-ray pulse of approximate duration of one picosecond. The projected thickness of homogeneous samples of various polymers is recovered quantitatively from the time-averaged intensity of transmitted X-rays. The data are in good agreement with the expectations showing that ATF Inverse Compton Scattering source is suitable for performing phase-sensitive quantitative X-ray imaging on the picosecond scale. The method shows promise for quantitative imaging of fast dynamic phenomena.

  13. THE NATURE OF THE UV/OPTICAL EMISSION OF THE ULTRALUMINOUS X-RAY SOURCE IN HOLMBERG II

    SciTech Connect

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

    2012-05-10

    We report on UV and X-ray spectroscopy and broadband optical observations of the ultraluminous X-ray source in Holmberg II. Fitting various stellar spectral models to the combined, non-simultaneous data set, we find that normal metallicity stellar spectra are ruled out by the data, while low-metallicity, Z = 0.1 Z{sub Sun }, late O-star spectra provide marginally acceptable fits, if we allow for the fact that X-ray ionization from the compact object may reduce or eliminate UV absorption/emission lines from the stellar wind. By contrast, an irradiated disk model fits both UV and optical data with {chi}{sup 2}/dof = 175.9/178, and matches the nebular extinction with a reddening of E(B - V) = 0.05{sup +0.05}{sub -0.04}. These results suggest that the UV/optical flux of Holmberg II X-1 may be dominated by X-ray irradiated disk emission.

  14. The deep census of the X-ray source populations in the Small Magellanic Cloud

    NASA Astrophysics Data System (ADS)

    Zezas, A.; Antoniou, V.; SMC XVP Collaboration

    2014-07-01

    We present the first results from the Chandra Deep Survey of the Small Magellanic Cloud (SMC). The goal of this project is to characterize the X-ray sources detected in the 1.1 Ms Chandra survey of the SMC, which provides a census of their populations down to a luminosity of 10^32 erg/s in 11 fields sampling young (10-100 Myr) stellar populations of different ages. We detect between 50-90 X-ray sources in each field, for which we measure their photometric and spectroscopic parameters. Analysis of their light-curves is used to identify accreting pulsars and flaring objects. The initial X-ray source lists have been cross-correlated with optical and IR photometric and spectroscopic catalogs (such as the OGLE and SAGE). We have determined the most likely optical counterpart for those sources, and based on the combination of their X-ray and multiwavelength properties, we identify candidate Be-XRBs and interlopers (foreground stars and AGN). The X-ray luminosity function of the Be-XRBs shows clear evidence for a break at low luminosities that is consistent with the onset of the propeller effect. Finally we present the first results from an analysis of the clustering of the X-ray binaries in the SMC with stellar populations of different ages.

  15. VizieR Online Data Catalog: Ultraluminous X-ray sources in nearby galaxies (Liu+, 2005)

    NASA Astrophysics Data System (ADS)

    Liu, J.-F.; Bregman, J. N.

    2005-08-01

    X-ray observations have revealed in other galaxies a class of extranuclear X-ray point sources with X-ray luminosities of 1039-1041ergs/s, exceeding the Eddington luminosity for stellar mass X-ray binaries. These ultraluminous X-ray sources (ULXs) may be powered by intermediate-mass black holes of a few thousand MSun or stellar mass black holes with special radiation processes. In this paper, we present a survey of ULXs in 313 nearby galaxies with D25>1 within 40Mpc with 467 ROSAT High Resolution Imager (HRI) archival observations. The HRI observations are reduced with uniform procedures, refined by simulations that help define the point source detection algorithm employed in this survey. A sample of 562 extragalactic X-ray point sources with LX=1038-1043ergs/s is extracted from 173 survey galaxies, including 106 ULX candidates within the D25 isophotes of 63 galaxies and 110 ULX candidates between 1D25 and 2D25 of 64 galaxies, from which a clean sample of 109 ULXs is constructed to minimize the contamination from foreground or background objects. (3 data files).

  16. A theoretical study on phase-contrast mammography with Thomson-scattering x-ray sources

    SciTech Connect

    De Caro, Liberato; Giannini, Cinzia; Bellotti, Roberto; Tangaro, Sabina

    2009-10-15

    Purpose: The x-ray transmitted beam from any material/tissue depends on the complex refractive index (n=1-{delta}+i{beta}), where {delta} is responsible for the phase shift and {beta} is for the beam attenuation. Although for human tissues, the {delta} cross section is about 1000 times greater than the {beta} ones in the x-ray energy range from 10 to 150 keV, the gain in breast tumor visualization of phase-contrast mammography (PCM) with respect to absorption contact imaging (AI) is limited by the maximum dose that can be delivered to the patient. Moreover, in-line PC imaging (PCI) is the simplest experimental mode among all available x-ray PCI techniques since no optics are needed. The latter is a fundamental requirement in order to transfer the results of laboratory research into hospitals. Alternative to synchrotron radiation sources, the implementation of relativistic Thomson-scattering (TS) x-ray sources is particularly suitable for hospital use because of their high peak brightness within a relatively compact and affordable system. In this work, the possibility to realize PCM using a TS source in a hospital environment is studied, accounting for the effect of a finite deliverable dose on the PC visibility enhancement with respect to AI. Methods: The contrast-to-noise ratio of tumor-tissue lesions in PCM has been studied on the bases of a recent theoretical model, describing image contrast formation by means of both wave-optical theory and the mutual coherence formalism. The latter is used to describe the evolution, during wave propagation, of the coherence of the wave field emitted by a TS source. The contrast-to-noise ratio for both PCI and AI has been analyzed in terms of tumor size, beam energy, detector, and source distances, studying optimal conditions for performing PCM. Regarding other relevant factors which could influence ''tumor'' visibility, the authors have assumed simplified conditions such as a spherical shape description of the tumor inclusion

  17. Optical Synchronization Systems for Femtosecond X-raySources

    SciTech Connect

    Wilcox, Russell; Staples, John W.; Holzwarth, Ronald

    2004-05-09

    In femtosecond pump/probe experiments using short X-Ray and optical pulses, precise synchronization must be maintained between widely separated lasers in a synchrotron or FEL facility. We are developing synchronization systems using optical signals for applications requiring different ranges of timing error over 100 meter of glass fiber. For stabilization in the hundred femtosecond range a CW laser is amplitude modulated at 1 10 GHz, the signal retroreflected from the far end, and the relative phase used to correct the transit time with a piezoelectric phase modulator. For the sub-10 fsec range the laser frequency itself is upshifted 55 MHz with an acousto-optical modulator, retroreflected, upshifted again and phase compared at the sending end to a 110 MHz reference. Initial experiments indicate less than 1 fsec timing jitter. To lock lasers in the sub-10 fs range we will lock two single-frequency lasers separated by several tera Hertz to a master modelocked fiber laser, transmit the two frequencies over fiber, and lock two comb lines of a slave laser to these frequencies, thus synchronizing the two modelocked laser envelopes.

  18. Studies of a prototype linear stationary x-ray source for tomosynthesis imaging

    NASA Astrophysics Data System (ADS)

    Schwoebel, P. R.; Boone, John M.; Shao, Joe

    2014-05-01

    A prototype linear x-ray source to implement stationary source-stationary detector tomosynthesis (TS) imaging has been studied. Potential applications include human breast and small animal imaging. The source is comprised of ten x-ray source elements each consisting of a field emission cathode, electrostatic lens, and target. The electrostatic lens and target are common to all elements. The source elements form x-ray focal spots with minimum diameters of 0.3-0.4 mm at electron beam currents of up to 40 mA with a beam voltage of 40 kV. The x-ray flux versus time was quantified from each source. X-ray bremsstrahlung spectra from tungsten targets were produced using electron beam energies from 35 to 50 keV. The half-value layer was measured to be 0.8, 0.9, and 1.0 mm, respectively, for the 35, 40, and 45 kV tube potentials using the tungsten target. The suppression of voltage breakdown events, particularly during source operation, and the use of a modified form of the standard cold-cathode geometry, enhanced source reliability. The prototype linear source was used to collect tomographic data sets of a mouse phantom using digital TS reconstruction methods and demonstrated a slice-sensitivity profile with a full-width-half-maximum of 1.3 mm. Lastly, preliminary studies of tomographic imaging of flow through the mouse phantom were performed.

  19. Development of grating-based x-ray Talbot interferometry at the advanced photon source

    SciTech Connect

    Marathe, Shashidhara; Xiao Xianghui; Wojcik, Michael J.; Divan, Ralu; Butler, Leslie G.; Ham, Kyungmin; Fezzaa, Kamel; Erdmann, Mark; Wen, Han H.; Lee, Wah-Keat; Macrander, Albert T.; De Carlo, Francesco; Mancini, Derrick C.; Assoufid, Lahsen

    2012-07-31

    We report on the ongoing effort to develop hard x-ray Talbot interferometry at the Advanced Photon Source (APS), Argonne National Laboratory, USA. We describe the design of the interferometer and preliminary results obtained at 25 keV using a feather and a phantom sample lithographically fabricated of gold. We mention the future developmental goals and applications of this technique as a metrology tool for x-ray optics and beam wavefront characterization.

  20. X-ray phase imaging with a laboratory source using selective reflection from a mirror.

    PubMed

    Pelliccia, Daniele; Paganin, David M

    2013-04-22

    A novel approach for hard x-ray phase contrast imaging with a laboratory source is reported. The technique is based on total external reflection from the edge of a mirror, aligned to intercept only half of the incident beam. The mirror edge thus produces two beams. The refraction x-rays undergo when interacting with a sample placed before the mirror, causes relative intensity variations between direct and reflected beams. Quantitative phase contrast and pure absorption imaging are demonstrated using this method.

  1. The SPARX Project: R & D Activity Towards X-Rays FEL Sources

    SciTech Connect

    Alesini, D.; Bellaveglia, M.; Bertolucci, S.; Biagini, M.E.; Boni, R.; Boscolo, M.; Castellano, M.; Clozza, A.; Di Pirro, G.; Drago, A.; Esposito, A.; Ferrario, M.; Filippetto, D.; Fusco, V.; Gallo, A.; Ghigo, A.; Guiducci, S.; Incurvati, M.; Ligi, C.; Marcellini, F.; Migliorati, M.; /Frascati /ENEA, Frascati /INFN, Milan /INFN, Rome /INFN, Rome2 /Milan Polytechnic /UCLA /SLAC

    2005-08-05

    SPARX is an evolutionary project proposed by a collaboration among ENEA-INFN-CNR-Universita di Roma Tor Vergata aiming at the construction of a FELSASE X-ray source in the Tor Vergata Campus. The first phase of the SPARX project, funded by Government Agencies, will be focused on R&D activity on critical components and techniques for future X-ray facilities as described in this paper.

  2. THE LUMINOSITY FUNCTION OF X-RAY SOURCES IN SPIRAL GALAXIES

    SciTech Connect

    Prestwich, A. H.; Primini, F.; McDowell, J. C.; Zezas, A.; Kilgard, R. E.

    2009-11-10

    X-ray sources in spiral galaxies can be approximately classified into bulge and disk populations. The bulge (or hard) sources have X-ray colors which are consistent with low-mass X-ray binaries (LMXBs) but the disk sources have softer colors suggesting a different type of source. In this paper, we further study the properties of hard and soft sources by constructing color-segregated X-ray luminosity functions (XLFs) for these two populations. Since the number of sources in any given galaxy is small, we co-added sources from a sample of nearby, face-on spiral galaxies observed by Chandra as a Large Project in Cycle 2. We use simulations to carefully correct the XLF for completeness. The composite hard source XLF is not consistent with a single-power-law fit. At luminosities L{sub x} > 3 x 10{sup 38} erg s{sup -1}, it is well fitted by a power law with a slope that is consistent with that found for sources in elliptical galaxies by Kim and Fabbiano. This supports the suggestion that the hard sources are dominated by LMXBs. In contrast, the high-luminosity XLF of soft sources has a slope similar to the 'universal' high-mass X-ray binary XLF. Some of these sources are stellar-mass black hole binaries accreting at high rates in a thermal/steep power-law state. The softest sources have inferred disk temperatures that are considerably lower than found in galactic black holes binaries. These sources are not well understood, but some may be super-soft ultra-luminous X-ray sources in a quiescent state as suggested by Soria and Ghosh.

  3. An all-optical Compton source for single-exposure x-ray imaging

    NASA Astrophysics Data System (ADS)

    Döpp, A.; Guillaume, E.; Thaury, C.; Gautier, J.; Andriyash, I.; Lifschitz, A.; Malka, V.; Rousse, A.; Phuoc, K. Ta

    2016-03-01

    All-optical Compton sources are innovative, compact devices to produce high energy femtosecond x-rays. Here we present results on a single-pulse scheme that uses a plasma mirror to reflect the drive beam of a laser plasma accelerator and to make it collide with the highly-relativistic electrons in its wake. The accelerator is operated in the self-injection regime, producing quasi-monoenergetic electron beams of around 150 MeV peak energy. Scattering with the intense femtosecond laser pulse leads to the emission of a collimated high energy photon beam. Using continuum-attenuation filters we measure significant signal content beyond 100 keV and with simulations we estimate a peak photon energy of around 500 keV. The source divergence is about 13 mrad and the pointing stability is 7 mrad. We demonstrate that the photon yield from the source is sufficiently high to illuminate a centimeter-size sample placed 90 centimeters behind the source, thus obtaining radiographs in a single shot.

  4. Bright x-ray stainless steel K-shell source development at the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    May, M. J.; Fournier, K. B.; Colvin, J. D.; Barrios, M. A.; Dewald, E. L.; Hohenberger, M.; Moody, J.; Patterson, J. R.; Schneider, M.; Widmann, K.; Regan, S. P.

    2015-06-01

    High x-ray conversion efficiency (XRCE) K-shell sources are being developed for high energy density experiments for use as backlighters and for the testing of materials exposed to high x-ray fluxes and fluences. Recently, sources with high XRCE in the K-shell x-ray energy range of iron and nickel were investigated at the National Ignition Facility (NIF). The x-ray conversion efficiency in the 5-9 keV spectral range was determined to be 6.8% ± 0.3%. These targets were 4.1 mm diameter, 4 mm tall hollow epoxy tubes having a 50 μm thick wall supporting a tube of 3 to 3.5 μm thick stainless steel. The NIF laser deposited ˜460 kJ of 3ω light into the target in a 140 TW, 3.3 ns square pulse. The absolute x-ray emission of the source was measured by two calibrated Dante x-ray spectrometers. Time resolved images filtered for the Fe K-shell were recorded to follow the heating of the target. Time integrated high-resolution spectra were recorded in the K-shell range.

  5. Bright x-ray stainless steel K-shell source development at the National Ignition Facility

    SciTech Connect

    May, M. J.; Fournier, K. B.; Colvin, J. D.; Barrios, M. A.; Dewald, E. L.; Moody, J.; Patterson, J. R.; Schneider, M.; Widmann, K.; Hohenberger, M.; Regan, S. P.

    2015-06-15

    High x-ray conversion efficiency (XRCE) K-shell sources are being developed for high energy density experiments for use as backlighters and for the testing of materials exposed to high x-ray fluxes and fluences. Recently, sources with high XRCE in the K-shell x-ray energy range of iron and nickel were investigated at the National Ignition Facility (NIF). The x-ray conversion efficiency in the 5–9 keV spectral range was determined to be 6.8% ± 0.3%. These targets were 4.1 mm diameter, 4 mm tall hollow epoxy tubes having a 50 μm thick wall supporting a tube of 3 to 3.5 μm thick stainless steel. The NIF laser deposited ∼460 kJ of 3ω light into the target in a 140 TW, 3.3 ns square pulse. The absolute x-ray emission of the source was measured by two calibrated Dante x-ray spectrometers. Time resolved images filtered for the Fe K-shell were recorded to follow the heating of the target. Time integrated high-resolution spectra were recorded in the K-shell range.

  6. Phase Contrast Imaging with Coded Apertures Using Laboratory-Based X-ray Sources

    SciTech Connect

    Ignatyev, K.; Munro, P. R. T.; Speller, R. D.; Olivo, A.

    2011-09-09

    X-ray phase contrast imaging is a powerful technique that allows detection of changes in the phase of x-ray wavefronts as they pass through a sample. As a result, details not visible in conventional x-ray absorption imaging can be detected. Until recently the majority of applications of phase contrast imaging were at synchrotron facilities due to the availability of their high flux and coherence; however, a number of techniques have appeared recently that allow phase contrast imaging to be performed using laboratory sources. Here we describe a phase contrast imaging technique, developed at University College London, that uses two coded apertures. The x-ray beam is shaped by the pre-sample aperture, and small deviations in the x-ray propagation direction are detected with the help of the detector aperture. In contrast with other methods, it has a much more relaxed requirement for the source size (it works with source sizes up to 100 {mu}m). A working prototype coded-aperture system has been built. An x-ray detector with directly deposited columnar CsI has been used to minimize signal spill-over into neighboring pixels. Phase contrast images obtained with the system have demonstrated its effectiveness for imaging low-absorption materials.

  7. 600 eV falcon-linac thomson x-ray source

    SciTech Connect

    Crane, J K; LeSage, G P; Ditmire, T; Cross, R; Wharton, K; Moffitt, K; Cowan, T E; Hays, G; Tsai, V; Anderson, G; Shuttlesworth, R; Springer, P

    2000-12-15

    The advent of 3rd generation light sources such as the Advanced Light Source (ALS) at LBL, and the Advanced Photon Source at Argonne, have produced a revolution in x-ray probing of dense matter during the past decade. These machines use electron-synchrotrons in conjunction with undulator stages to produce 100 psec x-ray pulses with photon energies of several kiloelectronvolts (keV). The applications for x-ray probing of matter are numerous and diverse with experiments in medicine and biology, semiconductors and materials science, and plasma and solid state physics. In spite of the success of the 3rd generation light sources there is strong motivation to push the capabilities of x-ray probing into new realms, requiring shorter pulses, higher brightness and harder x-rays. A 4th generation light source, the Linac Coherent Light Source (LCLS), is being considered at the Stanford Linear Accelerator [1]. The LCLS will produce multi-kilovolt x-rays of subpicosecond duration that are 10 orders of magnitude brighter than today's 3rd generation light sources.[1] Although the LCLS will provide unprecedented capability for performing time-resolved x-ray probing of ultrafast phenomena at solid densities, this machine will not be completed for many years. In the meantime there is a serious need for an ultrashort-pulse, high-brightness, hard x-ray source that is capable of probing deep into high-Z solid materials to measure dynamic effects that occur on picosecond time scales. Such an instrument would be ideal for probing the effects of shock propagation in solids using Bragg and Laue diffraction. These techniques can be used to look at phase transitions, melting and recrystallization, and the propagation of defects and dislocations well below the surface in solid materials. [2] These types of dynamic phenomena undermine the mechanical properties of metals and are of general interest in solid state physics, materials science, metallurgy, and have specific relevance to stockpile

  8. ROSAT X-ray sources embedded in the rho Ophiuchi cloud core

    NASA Astrophysics Data System (ADS)

    Casanova, Sophie; Montmerle, Thierry; Feigelson, Eric D.; Andre, Philippe

    1995-02-01

    We present a deep ROSAT Position Sensitive Proportional Counter (PSPC) image of the central region of the rho Oph star-forming region. The selected area, about 35 x 35 arcmins in size, is rich with dense molecular cores and young stellar objects (YSOs). Fifty-five reliable X-ray sources are detected (and up to 50 more candidates may be present) above approximately 1 keV,, doubling the number of Einstein sources in this area. These sources are cross-identified with an updated list of 88 YSOs associated with the rho Oph cloud core. A third of the reliable X-ray sources do not have optical counterparts on photographic plates. Most can be cross-identified wth Class II and Class III infrared (IR) sources, which are embedded T Tauri stars, but three reliable X-ray sources and up to seven candidate sources are tentatively identified with Class I protostars. Eighteen reliable, and up to 20 candidate, X-ray sources are probably new cloud members. The overall detection rate of the bona fide cloud population is very high (73% for the Class II and Class III objects). The spatial distribution of the X-ray sources closely follows that of the moleclar gas. The visual extinctions Av estimated from near-IR data) of the ROSAT sources can be as high as 50 or more, confirming that most are embedded in the cloud core and are presumably very young. Using bolometric luminosities Lbol estimated from J-magnitudes a tight correlation between Lx and Lbol is found, similar to that seen for older T Tauri stars in the Cha I cloud: Lx approximately 10-4 Lbol. A general relation Lxproportional to LbolLj seems to apply to all T Tauri-like YSOs. The near equality of the extintion in the IR J band and in the keV X-ray rage implies that this relation is valid for the detected fluxes as well as for the dereddened fluxes. The X-ray luminosity function of the embedded sourced in rho Oph spans a range of Lx approximately 1028.5 to approximately equal to or greater than 1031.5 ergs/s and is statistically

  9. X-ray source assembly having enhanced output stability, and fluid stream analysis applications thereof

    DOEpatents

    Radley, Ian; Bievenue, Thomas J.; Burdett Jr., John H.; Gallagher, Brian W.; Shakshober, Stuart M.; Chen, Zewu; Moore, Michael D.

    2007-04-24

    An x-ray source assembly (2700) and method of operation are provided having enhanced output stability. The assembly includes an anode (2125) having a source spot upon which electrons (2120) impinge and a control system (2715/2720) for controlling position of the anode source spot relative to an output structure. The control system can maintain the anode source spot location relative to the output structure (2710) notwithstanding a change in one or more operating conditions of the x-ray source assembly. One aspect of the disclosed invention is most amenable to the analysis of sulfur in petroleum-based fuels.

  10. X-ray source assembly having enhanced output stability, and fluid stream analysis applications thereof

    DOEpatents

    Radley, Ian; Bievenue, Thomas J.; Burdett, John H.; Gallagher, Brian W.; Shakshober, Stuart M.; Chen, Zewu; Moore, Michael D.

    2008-06-08

    An x-ray source assembly and method of operation are provided having enhanced output stability. The assembly includes an anode having a source spot upon which electrons impinge and a control system for controlling position of the anode source spot relative to an output structure. The control system can maintain the anode source spot location relative to the output structure notwithstanding a change in one or more operating conditions of the x-ray source assembly. One aspect of the disclosed invention is most amenable to the analysis of sulfur in petroleum-based fuels.

  11. Characteristics of a molybdenum X-pinch X-ray source as a probe source for X-ray diffraction studies

    SciTech Connect

    Zucchini, F.; Chauvin, C.; Combes, P.; Sol, D.; Loyen, A.; Roques, B.; Grunenwald, J.; Bland, S. N.

    2015-03-15

    X-ray emission from a molybdenum X-pinch has been investigated as a potential probe for the high pressure states made in dynamic compression experiments. Studies were performed on a novel 300 kA, 400 ns generator which coupled the load directly to a low inductance capacitor and switch combination. The X-pinch load consisted of 4 crossed molybdenum wires of 13 μm diameter, crossed at an angle of 62°. The load height was 10 mm. An initial x-ray burst generated at the wire crossing point, radiated in the soft x-ray range (hυ < 10 keV). This was followed, 2–5 ns later, by at least one harder x-ray burst (hυ > 10 keV) whose power ranged from 1 to 7 MW. Time integrated spectral measurements showed that the harder bursts were dominated by K-alpha emission; though, a lower level, wide band continuum up to at least 30 keV was also present. Initial tests demonstrated that the source was capable of driving Laue diffraction experiments, probing uncompressed samples of LiF and aluminium.

  12. Characteristics of a molybdenum X-pinch X-ray source as a probe source for X-ray diffraction studies.

    PubMed

    Zucchini, F; Bland, S N; Chauvin, C; Combes, P; Sol, D; Loyen, A; Roques, B; Grunenwald, J

    2015-03-01

    X-ray emission from a molybdenum X-pinch has been investigated as a potential probe for the high pressure states made in dynamic compression experiments. Studies were performed on a novel 300 kA, 400 ns generator which coupled the load directly to a low inductance capacitor and switch combination. The X-pinch load consisted of 4 crossed molybdenum wires of 13 μm diameter, crossed at an angle of 62°. The load height was 10 mm. An initial x-ray burst generated at the wire crossing point, radiated in the soft x-ray range (hυ < 10 keV). This was followed, 2-5 ns later, by at least one harder x-ray burst (hυ > 10 keV) whose power ranged from 1 to 7 MW. Time integrated spectral measurements showed that the harder bursts were dominated by K-alpha emission; though, a lower level, wide band continuum up to at least 30 keV was also present. Initial tests demonstrated that the source was capable of driving Laue diffraction experiments, probing uncompressed samples of LiF and aluminium. PMID:25832229

  13. Characteristics of a molybdenum X-pinch X-ray source as a probe source for X-ray diffraction studies

    NASA Astrophysics Data System (ADS)

    Zucchini, F.; Bland, S. N.; Chauvin, C.; Combes, P.; Sol, D.; Loyen, A.; Roques, B.; Grunenwald, J.

    2015-03-01

    X-ray emission from a molybdenum X-pinch has been investigated as a potential probe for the high pressure states made in dynamic compression experiments. Studies were performed on a novel 300 kA, 400 ns generator which coupled the load directly to a low inductance capacitor and switch combination. The X-pinch load consisted of 4 crossed molybdenum wires of 13 μm diameter, crossed at an angle of 62°. The load height was 10 mm. An initial x-ray burst generated at the wire crossing point, radiated in the soft x-ray range (hυ < 10 keV). This was followed, 2-5 ns later, by at least one harder x-ray burst (hυ > 10 keV) whose power ranged from 1 to 7 MW. Time integrated spectral measurements showed that the harder bursts were dominated by K-alpha emission; though, a lower level, wide band continuum up to at least 30 keV was also present. Initial tests demonstrated that the source was capable of driving Laue diffraction experiments, probing uncompressed samples of LiF and aluminium.

  14. Characteristics of a molybdenum X-pinch X-ray source as a probe source for X-ray diffraction studies.

    PubMed

    Zucchini, F; Bland, S N; Chauvin, C; Combes, P; Sol, D; Loyen, A; Roques, B; Grunenwald, J

    2015-03-01

    X-ray emission from a molybdenum X-pinch has been investigated as a potential probe for the high pressure states made in dynamic compression experiments. Studies were performed on a novel 300 kA, 400 ns generator which coupled the load directly to a low inductance capacitor and switch combination. The X-pinch load consisted of 4 crossed molybdenum wires of 13 μm diameter, crossed at an angle of 62°. The load height was 10 mm. An initial x-ray burst generated at the wire crossing point, radiated in the soft x-ray range (hυ < 10 keV). This was followed, 2-5 ns later, by at least one harder x-ray burst (hυ > 10 keV) whose power ranged from 1 to 7 MW. Time integrated spectral measurements showed that the harder bursts were dominated by K-alpha emission; though, a lower level, wide band continuum up to at least 30 keV was also present. Initial tests demonstrated that the source was capable of driving Laue diffraction experiments, probing uncompressed samples of LiF and aluminium.

  15. Intensity-Modulated Advanced X-ray Source (IMAXS) for Homeland Security Applications

    NASA Astrophysics Data System (ADS)

    Langeveld, Willem G. J.; Johnson, William A.; Owen, Roger D.; Schonberg, Russell G.

    2009-03-01

    X-ray cargo inspection systems for the detection and verification of threats and contraband require high x-ray energy and high x-ray intensity to penetrate dense cargo. On the other hand, low intensity is desirable to minimize the radiation footprint. A collaboration between HESCO/PTSE Inc., Schonberg Research Corporation and Rapiscan Laboratories, Inc. has been formed in order to design and build an Intensity-Modulated Advanced X-ray Source (IMAXS). Such a source would allow cargo inspection systems to achieve up to two inches greater imaging penetration capability, while retaining the same average radiation footprint as present fixed-intensity sources. Alternatively, the same penetration capability can be obtained as with conventional sources with a reduction of the average radiation footprint by about a factor of three. The key idea is to change the intensity of the source for each x-ray pulse based on the signal strengths in the inspection system detector array during the previous pulse. In this paper we describe methods to accomplish pulse-to-pulse intensity modulation in both S-band (2998 MHz) and X-band (9303 MHz) linac sources, with diode or triode (gridded) electron guns. The feasibility of these methods has been demonstrated. Additionally, we describe a study of a shielding design that would allow a 6 MV X-band source to be used in mobile applications.

  16. Laboratory-size three-dimensional x-ray microscope with Wolter type I mirror optics and an electron-impact water window x-ray source

    SciTech Connect

    Ohsuka, Shinji; Ohba, Akira; Onoda, Shinobu; Nakamoto, Katsuhiro; Nakano, Tomoyasu; Miyoshi, Motosuke; Soda, Keita; Hamakubo, Takao

    2014-09-15

    We constructed a laboratory-size three-dimensional water window x-ray microscope that combines wide-field transmission x-ray microscopy with tomographic reconstruction techniques, and observed bio-medical samples to evaluate its applicability to life science research fields. It consists of a condenser and an objective grazing incidence Wolter type I mirror, an electron-impact type oxygen Kα x-ray source, and a back-illuminated CCD for x-ray imaging. A spatial resolution limit of around 1.0 line pairs per micrometer was obtained for two-dimensional transmission images, and 1-μm scale three-dimensional fine structures were resolved.

  17. Laboratory-size three-dimensional x-ray microscope with Wolter type I mirror optics and an electron-impact water window x-ray source.

    PubMed

    Ohsuka, Shinji; Ohba, Akira; Onoda, Shinobu; Nakamoto, Katsuhiro; Nakano, Tomoyasu; Miyoshi, Motosuke; Soda, Keita; Hamakubo, Takao

    2014-09-01

    We constructed a laboratory-size three-dimensional water window x-ray microscope that combines wide-field transmission x-ray microscopy with tomographic reconstruction techniques, and observed bio-medical samples to evaluate its applicability to life science research fields. It consists of a condenser and an objective grazing incidence Wolter type I mirror, an electron-impact type oxygen Kα x-ray source, and a back-illuminated CCD for x-ray imaging. A spatial resolution limit of around 1.0 line pairs per micrometer was obtained for two-dimensional transmission images, and 1-μm scale three-dimensional fine structures were resolved.

  18. A microfocus x-ray source based on a nonmetal liquid-jet anode

    SciTech Connect

    Tuohimaa, T.; Ewald, J.; Schlie, M.; Hertz, H. M.; Vogt, U.

    2008-06-09

    We demonstrate stable operation of a nonmetallic anode in an electron-impact x-ray source. A high-brightness electron beam is focused on a {approx}70 m/s speed, {approx}10 {mu}m diameter methanol jet producing stable x-ray emission with peak spectral brightness at {approx}5.4x10{sup 5} photons/(sx{mu}m{sup 2}xsrx0.1%BW). The jet is fully evaporated in the interaction point. The shape of a simulated spectrum using Monte Carlo methods shows good agreement with experimental data, and the theoretical brightness values give an upper limit for the achievable x-ray emission from jets with very high velocities. Using this anode concept, all compounds and elements found in liquid form are potentially usable for x-ray generation.

  19. Initial feasibility study of a dedicated synchrotron radiation light source for ultrafast X-ray science

    SciTech Connect

    Corlett, John N.; DeSantis, S.; Hartman, N.; Heimann, P.; LaFever, R.; Li, D.; Padmore, H.; Rimmer, R.; Robinson, K.; Schoenlein, R.; Tanabe, J.; Wang, S.; Zholents, A.; Kairan, D.

    2001-10-26

    We present an initial feasibility summary of a femtosecond synchrotron radiation x-ray source based on a flat-beam rf gun and a recirculating superconducting linac that provides beam to an array of undulators and bend magnets. Optical pulse durations of < 100 fs are obtained by a combination of electron pulse compression, transverse temporal correlation of the electrons, and x-ray pulse compression. After an introduction and initial scientific motivation, we cover the following aspects of the design: layout and lattice, ultra-fast x-ray pulse production, flat electron-beam production, the rf gun, rf systems, cryogenic systems, collective effects, photon production, and synchronization of x-ray and laser pulses. We conclude with a summary of issues and areas of development that remain to be addressed.

  20. Multilayer-Based Optics for High-Brightness X-ray Sources

    SciTech Connect

    Bajt, S.; Barthelmess, M.; Chapman, H. N.; Aquila, A.; Krzywinski, J.; Nelson, A. J.

    2011-09-09

    High-brightness x-ray sources, such as next-generation synchrotrons and free-electron lasers (FELs), pose unique challenges for the development of x-ray optics. The peak intensities of FEL pulses can be high enough to convert any material placed in a focused beam into plasma. X-ray optics, which are used close to the focal spot, are likely to be partially or completely damaged in a single shot. Such optics would need to be replenished after each shot. Optics that are used in the unfocused or indirect beam may survive much longer, perhaps indefinitely, if care is used to limit the energy absorbed in the optics. Here we present different types of multilayer-based optics, which were used successfully in FEL experiments for reflecting, focusing, and filtering high-intensity, pulsed x-rays in a variety of novel science applications.

  1. Calibration Of A KrF Laser-Plasma Source For X-Ray Microscopy Applications

    NASA Astrophysics Data System (ADS)

    Turcu, I. C. E.; O'Neill, F.; Zammit, U.; Al-Hadithi, Y.; Eason, R. W.; Rogayski, A. M.; Hills, C. P. B.; Michette, A. G.

    1988-02-01

    Plasma X-ray sources for biological microscopy in the water-window have been produced by focusing tige 200 3, 50 ns Sprit q KrF laser onto carbon targets at irradiance between 2.2 x 10" W/cm4 and 3.7 x 10i3W/cm. Absolute measurements of X-ray production have been made using a calibrated, vacuum X-ray diode detector. A peak conversion efficiency . 10% is measured from KrF laseri)Tight tcto wate-window X-rays at 280 eV < hv < 530 eV for a target irradiance . 1 x x 10 W/cm'. Some measurements with gold and tungsten targets give conversion efficiencies 2$25% at a similar laser irradiance.

  2. Chandra Studies of Unidentified X-ray Sources in the Galactic Bulge

    NASA Astrophysics Data System (ADS)

    Mori, Hideyuki

    2013-09-01

    We propose to study a complete X-ray sample in the luminosity range of > 10^34 erg s^-1 in the Galactic bulge, including 5 unidentified sources detected in the ROSAT All Sky Survey. Our goal is to obtain a clear picture about X-ray populations in the bulge, by utilizing the excellent Chandra position accuracy leading to unique optical identification together with the X-ray spectral properties. This is a new step toward understanding the formation history of the bulge. Furthermore, because the luminosity range we observe corresponds to a ``missing link'' region ever studied for a neutron star or blackhole X-ray binary, our results are also unique to test accretion disk theories at intermediate mass accretion rates.

  3. Chandra Studies of Unidentified X-ray Sources in the Galactic Bulge

    NASA Astrophysics Data System (ADS)

    Mori, Hideyuki

    2010-09-01

    We propose to study a complete X-ray sample in the luminosity range of > 10^34 erg s^-1 in the Galactic bulge, consisting of 11 unidentified sources detected in the ROSAT All Sky Survey. Our goal is to obtain a clear picture about X-ray populations in the bulge, by utilizing the excellent Chandra position accuracy leading to unique optical identification together with the X-ray spectral properties. This is a new step toward understanding the formation history of the bulge. Furthermore, because the luminosity range we observe corresponds to a ``missing link'' region ever studied for a neutron star or blackhole X-ray binary, our results are also unique to test accretion disk theories at intermediate mass accretion rates.

  4. A Compton X-ray source based on a SC linac at KAERI

    NASA Astrophysics Data System (ADS)

    Bondarenko, A. V.; Han, Y. H.; Jeong, Y. U.; Lee, B. C.; Miginsky, S. V.; Park, S. H.

    2007-05-01

    A quasi-monochromatic X-ray source based on a KAERI SC linac system has been designed and is being manufactured now. 10 MeV 10 mA electron beam together with 20 W 1.06 μm laser beam will be used for 1.8 keV Compton X-ray generation with a few percentage of energy spread and 10 7 photons /s flux. A simple straight beamline was designed to deliver the electron beam with no degradation of its emittance and energy spread and to focus it to a proper size to produce the desired X-rays. We expect the first demonstration of 1.8 keV Compton X-ray generation in autumn 2006.

  5. Discovery of a highly variable dipping ultraluminous X-ray source in M94

    SciTech Connect

    Lin, Dacheng; Irwin, Jimmy A.; Webb, Natalie A.; Barret, Didier; Remillard, Ronald A.

    2013-12-20

    We report the discovery of a new ultraluminous X-ray source (ULX) 2XMM J125048.6+410743 within the spiral galaxy M94. The source has been observed by ROSAT, Chandra, and XMM-Newton on several occasions, exhibiting as a highly variable persistent source or a recurrent transient with a flux variation factor of ≳100, a high duty cycle (at least ∼70%), and a peak luminosity of L {sub X} ∼ 2 × 10{sup 39} erg s{sup –1} (0.2-10 keV, absorbed). In the brightest observation, the source is similar to typical low-luminosity ULXs, with the spectrum showing a high-energy cutoff but harder than that from a standard accretion disk. There are also sporadical short dips, accompanied by spectral softening. In a fainter observation with L {sub X} ∼ 3.6 × 10{sup 38} erg s{sup –1}, the source appears softer and is probably in the thermal state seen in Galactic black hole X-ray binaries (BHBs). In an even fainter observation (L {sub X} ∼ 9 × 10{sup 37} erg s{sup –1}), the spectrum is harder again, and the source might be in the steep-power-law state or the hard state of BHBs. In this observation, the light curve might exhibit ∼7 hr (quasi-)periodic large modulations over two cycles. The source also has a possible point-like optical counterpart from Hubble Space Telescope images. In terms of the colors and the luminosity, the counterpart is probably a G8 supergiant or a compact red globular cluster containing ∼2 × 10{sup 5} K dwarfs, with some possible weak UV excess that might be ascribed to accretion activity. Thus, our source is a candidate stellar-mass BHB with a supergiant companion or with a dwarf companion residing in a globular cluster. Our study supports that some low-luminosity ULXs are supercritically accreting stellar-mass BHBs.

  6. Chandra Observations of Diffuse Gas and Luminous X-Ray Sources around the X-Ray-bright Elliptical Galaxy NGC 1600

    NASA Astrophysics Data System (ADS)

    Sivakoff, Gregory R.; Sarazin, Craig L.; Carlin, Jeffrey L.

    2004-12-01

    We observed the X-ray-bright E3 galaxy NGC 1600 and nearby members of the NGC 1600 group with the Chandra X-Ray Observatory ACIS-S3 to study their X-ray properties. Unresolved emission dominates the observation; however, we resolved some of the emission into 71 sources, most of which are low-mass X-ray binaries associated with NGC 1600. Twenty-one of the sources have LX>2×1039 ergs s-1 (0.3-10.0 keV; assuming they are at the distance of NGC 1600), marking them as ultraluminous X-ray point source (ULX) candidates; we expect that only 11+/-2 are unrelated foreground/background sources. NGC 1600 may have the largest number of ULX candidates in an early-type galaxy to date; however, cosmic variance in the number of background active galactic nuclei cannot be ruled out. The spectrum and luminosity function (LF) of the resolved sources are more consistent with sources found in other early-type galaxies than with sources found in star-forming regions of galaxies. The source LF and the spectrum of the unresolved emission both indicate that there are a large number of unresolved point sources. We propose that these sources are associated with globular clusters (GCs) and that NGC 1600 has a large GC specific frequency. Observations of the GC population in NGC 1600 would be very useful for testing this prediction. Approximately 50%-75% of the unresolved flux comes from diffuse gaseous emission. The spectral fits, hardness ratios, and X-ray surface brightness profile all point to two gas components. We interpret the soft inner component (a<~25'', kT~0.85 keV) as the interstellar medium of NGC 1600 and the hotter outer component (a>~25'', kT~1.5 keV) as the intragroup medium of the NGC 1600 group. The X-ray image shows several interesting structures. First, there is a central region of excess emission that is roughly cospatial with Hα and dust filaments immediately west of the center of NGC 1600. There appear to be holes in the X-ray emission to the north and south of the

  7. Development of a Sub-Picosecond Tunable X-Ray Source at the LLNL Electron Linac

    SciTech Connect

    Slaughter, D; Springer, P; Le Sage, G; Crane, J; Ditmire, T; Cowan, T; Anderson, S G; Rosenzweig, J B

    2001-08-31

    The use of ultrafast laser pulses to generate very high brightness, ultra short (fs to ps) pulses of x-rays is a topic of great interest to the x-ray user community. In principle, femtosecond-scale pump-probe experiments can be used to temporally resolve structural dynamics of materials on the time scale of atomic motion. The development of sub-ps x-ray pulses will make possible a wide range of materials and plasma physics studies with unprecedented time resolution. A current project at LLNL will provide such a novel x-ray source based on Thomson scattering of high power, short laser pulses with a high peak brightness, relativistic electron bunch. The system is based on a 5 mm-mrad normalized emittance photoinjector, a 100 MeV electron RF linac, and a 300 mJ, 35 fs solid-state laser system. The Thomson x-ray source produces ultra fast pulses with x-ray energies capable of probing into high-Z metals, and a high flux per pulse enabling single shot experiments. The system will also operate at a high repetition rate ({approx} 10 Hz).

  8. Observation of X-ray sources with XRS onboard HAYABUSA spacecraft

    NASA Astrophysics Data System (ADS)

    Arai, T.; Yamamoto, Y.; Okada, T.; Shirai, K.; Kato, M.

    The HAYABUSA (MUSES-C) spacecraft was launched in Japan by the fifth M-V launch vehicle on May 9, 2003 will carry out rendezvous with near-Earth asteroid Itokawa (1998SF36), and return the samples to the Earth. An X-ray fluorescence spectrometer (XRS) onboard HAYABUSA has high-energy resolution (FWHM: 160eV@5.9keV) by using X-ray CCD, will allow for quantitative measurement of the surface elementals of asteroid, such as Mg, Al, Si, S, Ca, Ti, and Fe. Addition, the XRS has large effective area (25cm2) and suitable field of view for asteroid observation (3.5x3.5degrees). During the transfer and return phase, the HAYABUSA spacecraft will turn off the Ion propulsion thruster and point a high-gain antenna to the Earth station every week. Then, the XRS will observe X-ray sources such as super nova remnant, X-ray binaries and cosmic X-ray back ground for in-flight calibration and scientific observation. In this study, we report results of resent observations. The XRS observed Scorpius X-1 (May 28-30, 2003), Kepler's SNR (Jun. 16-18, 2003), Crab Nebula (Jan. 11-12, 2004), IC443 (Jan. 26, 2004). The XRS separated line X-ray spectra from Kepler's SNR and IC443 such as Si and S, clearly. These X-ray sources have been observed the X-ray astronomy satellite ASCA. We fitted power-law model or non-equilibrium ionization model (Borkowski, 2000) to the XRS observed spectra. However, the intensities were inconsistent with the best-fit models to ASCA observed spectra. Charge traps due to the space radiation may cause characteristic changes of the XRS. We will monitor the performance of the XRS and update the response function by in-flight calibration.

  9. Chandra Observation of the X-ray Source Population of NGC 6946

    NASA Technical Reports Server (NTRS)

    Holt, S. S.; Schlegel, E. M.; Hwang, U.; Petre, R.

    2003-01-01

    We present the results of a study of discrete X-ray sources in NGC 6946 using a deep Chandra ACIS observation. Based on the slope of the log N-log S distribution and the general correlation of sources with the spiral arms, we infer that the overall discrete source sample in NGC 6946 is dominated by high mass X-ray binaries, in contrast to the source distributions in M31 and the Milky Way. This is consistent with the higher star formation rate in NGC 6946 than in those galaxies. We find that the strong X-ray sources in the region of the galactic center do not correlate in detail with images of the region in the near-IR, although one of them may be coincident with the galactic center. The non-central ultra-luminous X-ray source in NGC 6946, previously identified with a supernova remnant, has an X-ray spectrum and luminosity that is inconsistent with either a traditional pulsar wind nebula or a blast wave remnant.

  10. ASCA Observation of Bright X-Ray Sources in the Nearby Spiral Galaxy IC 342

    NASA Astrophysics Data System (ADS)

    Okada, Kyoko; Dotani, Tadayasu; Makishima, Kazuo; Mitsuda, Kazuhisa; Mihara, Tatehiro

    1998-02-01

    X-ray observations of the nearby starburst galaxy IC 342 with ASCA led to the detection of three bright X-ray sources, whose positions are consistent with those from the Einstein and ROSAT observations. The X-ray luminosities of the two sources exceed the Eddington limit of a 1.4MO object by two orders of magnitude for an assumed distance of 4.5 Mpc. The brightest one (source 1) among the three exhibited significant time variations on a time scale of a few hours during the ASCA observation. Thus, the size of the emission region must be smaller than about 10(14) cm. The energy spectrum of the source can be represented either by a power-law with an exponential roll-over, or by an optically thick accretion disk model with a maximum color temperature of 1.77 keV. Although the large luminosity of source 1 may be explained by a ~ 100MO black hole at 4.5 Mpc, the observed energy spectrum is too hard to be accounted for by an optically thick accretion disk around the black hole. Ifsource1 is a relativistic jet source with strong X-ray beaming, both the large luminosity and the hard X-ray spectrum can be explained.

  11. Simultaneous observations of hard X-ray and microwave burst sources in a limb flare

    NASA Technical Reports Server (NTRS)

    Takakura, T.; Kundu, M. R.; Mcconnell, D.; Ohki, K.

    1985-01-01

    Observations of a flare which occurred just behind the west solar limb on 1981 August 3 are reported. A hard X-ray source (20-30 keV) and a microwave source at 5 GHz were observed simultaneously using the Very Large Array and the hard X-ray telescope aboard the Hinotori spacecraft. Both sources were located in the corona, apparently near the tops of two independent coronal arcades or loops. The source may be composed of many thin filaments unresolved by the VLA observations.

  12. Ultraviolet spectroscopy of the supersoft X-ray source RX J0439.8-6809

    NASA Astrophysics Data System (ADS)

    Van Teeseling, Andre

    1997-07-01

    Observationally, supersoft X-ray sources are classified as near-Eddington stellar objects with almost all emission at energies < 0.5 keV. Only 13 supersoft X-ray sources have been optically identified, and of these 11 turn out to be binaries, probably with a shell-burning accreting white dwarf. We have recently identified RX J0439.8-6809 with a V=21.63, very blue star in the LMC. A 3sigma upper limit to the peak-to-peak optical variability is 0.07 mag. Of all optically identified supersoft X-ray sources, RX J0439.8-6809 has the lowest optical-to-X-ray flux ratio. The nature of RX J0439.8-6809 is still unknown. It might be the hottest known pre-white dwarf, suffering a late helium shell flash. Alternatively, RX J0439.8-6809 could be an accreting binary, in which case it might be the first known double-degenerate supersoft X-ray source with a predicted orbital period of only a few minutes. An ultraviolet spectrum is essential to distinguish between these two spectacular possibilities, and to bridge the gap between the X-ray and optical observations. Such a spectrum can only be obtained with the HST STIS. Therefore, we propose to obtain two ultraviolet spectra, which will test the assumption that the optical spectrum is the Rayleigh-Jeans tail of the soft X-ray component, which will determine the spectral energy distribution, and which may provide the first direct evidence for accretion in this source by detecting an excess in the ultraviolet or ultraviolet emission lines like N V Lambda 1240.

  13. Line x-ray source for diffraction enhanced imaging in clinical and industrial applications

    NASA Astrophysics Data System (ADS)

    Wang, Xiaoqin

    Mammography is one type of imaging modalities that uses a low-dose x-ray or other radiation sources for examination of breasts. It plays a central role in early detection of breast cancers. The material similarity of tumor-cell and health cell, breast implants surgery and other factors, make the breast cancers hard to visualize and detect. Diffraction enhanced imaging (DEI), first proposed and investigated by D. Chapman is a new x-ray radiographic imaging modality using monochromatic x-rays from a synchrotron source, which produced images of thick absorbing objects that are almost completely free of scatter. It shows dramatically improved contrast over standard imaging when applied to the same phantom. The contrast is based not only on attenuation but also on the refraction and diffraction properties of the sample. This imaging method may improve image quality of mammography, other medical applications, industrial radiography for non-destructive testing and x-ray computed tomography. However, the size, and cost, of a synchrotron source limits the application of the new modality to be applicable at clinical levels. This research investigates the feasibility of a designed line x-ray source to produce intensity compatible to synchrotron sources. It is composed of a 2-cm in length tungsten filament, installed on a carbon steel filament cup (backing plate), as the cathode and a stationary oxygen-free copper anode with molybdenum coating on the front surface serves as the target. Characteristic properties of the line x-ray source were computationally studied and the prototype was experimentally investigated. SIMIION code was used to computationally study the electron trajectories emanating from the filament towards the molybdenum target. A Faraday cup on the prototype device, proof-of-principle, was used to measure the distribution of electrons on the target, which compares favorably to computational results. The intensities of characteristic x-ray for molybdenum

  14. Nonthermal X-Rays from Supernova Remnant G330.2+1.0 and the Characteristics of its Central Compact Object

    NASA Astrophysics Data System (ADS)

    Park, Sangwook; Kargaltsev, O.; Pavlov, G.; Mori, K.; Slane, P. O.; Hughes, J. P.; Burrows, D. N.; Garmire, G. P.

    2009-01-01

    We present results from our X-ray data analysis of the supernova remnant (SNR) G330.2+1.0 and its central compact object (CCO), CXOU J160103.1-513353 (J1601 hereafter). Using our XMM-Newton and Chandra observations, the X-ray spectrum of J1601 is described by neutron star (NS) atmosphere models, indicating a small hot region(s) (R 1-2 km, Th 2.5-3.7 MK) and the cool NS surface (R = 10 km, Ts < 1.5 MK). X-ray pulsations are not detected. However, our timing analysis of the XMM-Newton data is limited by poor photon statistics, and thus pulsations with a relatively low amplitude (i.e., an intrinsic pulsed-fraction < 40%) cannot be ruled out. Our results indicate that J1601 is a CCO similar to that in the Cassiopeia A SNR. X-ray emission from SNR G330.2+1.0 is dominated by power law continuum (photon index 2.1-2.5) which primarily originates from thin filaments along the boundary shell. This X-ray spectrum implies synchrotron radiation from shock-accelerated electrons with an exponential roll-off frequency 2-3 x 1017 Hz. For the measured widths of the X-ray filaments (D 0.3 pc) and the estimated shock velocity (vs a few x 103 km/s), a downstream magnetic field B 10-50 uG is derived. The estimated maximum electron energy Emax 27-38 TeV suggests that G330.2+1.0 is a candidate TeV source. We detect faint thermal X-ray emission in G330.2+1.0. We estimate a low preshock density n0 0.1 cm-3, which suggests a dominant contribution from an inverse Compton mechanism (than the proton-proton collision) to the prospective gamma-ray emission. Follow-up deep radio, X-ray, and gamma-ray observations will be essential to reveal the details of the shock parameters and the nature of particle accelerations in this SNR.

  15. A DEEP CHANDRA OBSERVATION OF THE GIANT H II REGION N11. I. X-RAY SOURCES IN THE FIELD

    SciTech Connect

    Nazé, Yaël; Wang, Q. Daniel; Chu, You-Hua; Gruendl, Robert; Oskinova, Lida

    2014-08-01

    A very sensitive X-ray investigation of the giant H II region N11 in the Large Megallanic Cloud was performed using the Chandra X-ray Observatory. The 300 ks observation reveals X-ray sources with luminosities down to 10{sup 32} erg s{sup –1}, increasing the number of known point sources in the field by more than a factor of five. Among these detections are 13 massive stars (3 compact groups of massive stars, 9 O stars, and one early B star) with log (L {sub X}/L {sub BOL}) ∼–6.5 to –7, which may suggest that they are highly magnetic or colliding-wind systems. On the other hand, the stacked signal for regions corresponding to undetected O stars yields log (L {sub X}/L {sub BOL}) ∼–7.3, i.e., an emission level comparable to similar Galactic stars despite the lower metallicity. Other point sources coincide with 11 foreground stars, 6 late-B/A stars in N11, and many background objects. This observation also uncovers the extent and detailed spatial properties of the soft, diffuse emission regions, but the presence of some hotter plasma in their spectra suggests contamination by the unresolved stellar population.

  16. MULTIBAND DIAGNOSTICS OF UNIDENTIFIED 1FGL SOURCES WITH SUZAKU AND SWIFT X-RAY OBSERVATIONS

    SciTech Connect

    Takeuchi, Y.; Kataoka, J.; Maeda, K.; Takahashi, Y.; Tahara, M.; Nakamori, T.

    2013-10-01

    We have analyzed all the archival X-ray data of 134 unidentified (unID) gamma-ray sources listed in the first Fermi/LAT (1FGL) catalog and subsequently followed up by the Swift/XRT. We constructed the spectral energy distributions (SEDs) from radio to gamma-rays for each X-ray source detected, and tried to pick up unique objects that display anomalous spectral signatures. In these analyses, we target all the 1FGL unID sources, using updated data from the second Fermi/LAT (2FGL) catalog on the Large Area Telescope (LAT) position and spectra. We found several potentially interesting objects, particularly three sources, 1FGL J0022.2–1850, 1FGL J0038.0+1236, and 1FGL J0157.0–5259, which were then more deeply observed with Suzaku as a part of an AO-7 program in 2012. We successfully detected an X-ray counterpart for each source whose X-ray spectra were well fitted by a single power-law function. The positional coincidence with a bright radio counterpart (currently identified as an active galactic nucleus, AGN) in the 2FGL error circles suggests these sources are definitely the X-ray emission from the same AGN, but their SEDs show a wide variety of behavior. In particular, the SED of 1FGL J0038.0+1236 is not easily explained by conventional emission models of blazars. The source 1FGL J0022.2–1850 may be in a transition state between a low-frequency peaked and a high-frequency peaked BL Lac object, and 1FGL J0157.0–5259 could be a rare kind of extreme blazar. We discuss the possible nature of these three sources observed with Suzaku, together with the X-ray identification results and SEDs of all 134 sources observed with the Swift/XRT.

  17. A POPULATION OF ULTRALUMINOUS X-RAY SOURCES WITH AN ACCRETING NEUTRON STAR

    SciTech Connect

    Shao, Yong; Li, Xiang-Dong

    2015-04-01

    Most ultraluminous X-ray sources (ULXs) are believed to be X-ray binary systems, but previous observational and theoretical studies tend to prefer a black hole rather than a neutron star (NS) accretor. The recent discovery of 1.37 s pulsations from the ULX M82 X-2 has established its nature as a magnetized NS. In this work we model the formation history of NS ULXs in an M82- or Milky Way (MW)-like Galaxy, by use of both binary population synthesis and detailed binary evolution calculations. We find that the birth rate is around 10{sup −4} yr{sup −1} for the incipient X-ray binaries in both cases. We demonstrate the distribution of the ULX population in the donor mass–orbital period plane. Our results suggest that, compared with black hole X-ray binaries, NS X-ray binaries may significantly contribute to the ULX population, and high-mass and intermediate-mass X-ray binaries dominate the NS ULX population in M82- and MW-like Galaxies, respectively.

  18. Absolute measurements of x-ray backlighter sources at energies above 10 keV

    SciTech Connect

    Maddox, B. R.; Park, H. S.; Remington, B. A.; Chen, C.; Chen, S.; Prisbrey, S. T.; Comley, A.; Back, C. A.; Szabo, C.; Seely, J. F.; Feldman, U.; Hudson, L. T.; Seltzer, S.; Haugh, M. J.; Ali, Z.

    2011-05-15

    Line emission and broadband x-ray sources with x-ray energies above 10 keV have been investigated using a range of calibrated x-ray detectors for use as x-ray backlighters in high energy density (HED) experiments. The conversion efficiency of short- and long-pulse driven Mo and Ag line-emission backlighters at 17 and 22 keV was measured to investigate the crossover region between short- and long-pulse conversion efficiency. It was found that significant 17 and 22 keV line emissions were observed using a 3 {omega}, 1 ns long-pulse drive for Mo and Ag targets and a comparison between the measured Mo x-ray spectrum and calculations using an atomic physics code suggests that the line emission is due to thermal emission from N-like Mo atoms. Electron temperatures derived from fits to the continuum region of the x-ray spectra agree well with the T{sub hot} scaling as 100x(I{lambda}{sup 2}){sup 1/3}. The continuum emissions from empty and 1 atm Kr-filled imploded CH shell targets were also measured for the use as broadband backlighters.

  19. Suzaku X-Ray Study of an Anomalous Source XSS J12270-4859

    NASA Astrophysics Data System (ADS)

    Saitou, Kei; Tsujimoto, Masahiro; Ebisawa, Ken; Ishida, Manabu

    2009-08-01

    We report on the results of a Suzaku X-ray observation of XSSJ12270-4859, one of the hard X-ray sources in the INTEGRAL catalogue. This object has been classified as an intermediate polar (IP) by its optical spectra, and a putative X-ray period of ˜860s. With a 30ks exposure by Suzaku, we obtained a well-exposed spectrum in the 0.2--70keV band. We conclude against a previous IP classification based on a lack of Fe Kα emission features in the spectrum and a failure to confirm the previously reported X-ray period. Instead, the X-ray light curve is filled with exotic phenomena, including repetitive flares lasting for ˜100s, occasional dips with no apparent periodicities, spectral hardening after some flares, and bimodal changes pivoting between quiet and active phases. The rapid flux changes, the dips, and the power-law spectrum point toward an interpretation that this is a low-mass X-ray binary. Some temporal characteristics are similar to those in the Rapid Burster and GRO J1744-28, making XSS J12270-4859 a very rare object.

  20. Development of a microfocus x-ray tube with multiple excitation sources

    SciTech Connect

    Maeo, Shuji; Kraemer, Markus; Taniguchi, Kazuo

    2009-03-15

    A microfocus x-ray tube with multiple targets and an electron gun with a focal spot size of 10 {mu}m in diameter has been developed. The electron gun contains a LaB{sub 6} cathode and an Einzel lens. The x-ray tube can be operated at 50 W (50 kV, 1 mA) and has three targets, namely, Cr, W, and Rh on the anode that can be selected completely by moving the anode position. A focal spot size of 10 {mu}m in diameter can be achieved at 0.5 mA current. As demonstration of the usability of a multiexcitation x-ray tube, the fluorescence x-rays have been measured using a powder specimen mixed of TiO{sub 2}, Co, and Zr of the same quantity. The differences of excitation efficiency have clearly appeared according to the change in excitation source. From the results discussed here, it can be expected that the presented x-ray tube will be a powerful tool in microx-ray fluorescence spectrometers and various x-ray instruments.

  1. Development of a microfocus x-ray tube with multiple excitation sources

    NASA Astrophysics Data System (ADS)

    Maeo, Shuji; Krämer, Markus; Taniguchi, Kazuo

    2009-03-01

    A microfocus x-ray tube with multiple targets and an electron gun with a focal spot size of 10 μm in diameter has been developed. The electron gun contains a LaB6 cathode and an Einzel lens. The x-ray tube can be operated at 50 W (50 kV, 1 mA) and has three targets, namely, Cr, W, and Rh on the anode that can be selected completely by moving the anode position. A focal spot size of 10 μm in diameter can be achieved at 0.5 mA current. As demonstration of the usability of a multiexcitation x-ray tube, the fluorescence x-rays have been measured using a powder specimen mixed of TiO2, Co, and Zr of the same quantity. The differences of excitation efficiency have clearly appeared according to the change in excitation source. From the results discussed here, it can be expected that the presented x-ray tube will be a powerful tool in microx-ray fluorescence spectrometers and various x-ray instruments.

  2. On the Thermal Line Emission from the Outflows in Ultraluminous X-Ray Sources

    NASA Astrophysics Data System (ADS)

    Xu, Ya-Di; Cao, Xinwu

    2016-08-01

    The atomic features in the X-ray spectra of ultraluminous X-ray sources (ULXs) may be associated with the outflow, which may provide a way to explore the physics of the ULXs. We construct a conical outflow model and calculate the thermal X-ray Fe emission lines from the outflows. Our results show that thermal line luminosity decreases with increasing outflow velocity and/or opening angle of the outflow for a fixed kinetic power of the outflows. Assuming the kinetic power of the outflows to be comparable with the accretion power in the ULXs, we find that the equivalent width can be several eV for the thermal X-ray Fe emission line from the outflows in the ULXs with stellar-mass black holes. The thermal line luminosity is proportional to 1/M bh (M bh is the black hole mass of the ULX). The equivalent width decreases with the black hole mass, which implies that the Fe line emission from the outflows can hardly be detected if the ULXs contain intermediate-mass black holes. Our results suggest that the thermal X-ray Fe line emission should be preferentially be detected in the ULXs with high kinetic power slowly moving outflows from the accretion disks surrounding stellar-mass black holes/neutron stars. The recently observed X-ray atomic features of the outflows in a ULX may imply that it contains a stellar-mass black hole.

  3. Chandra Observations of the X-Ray Point Source Population in NGC 4636

    NASA Astrophysics Data System (ADS)

    Posson-Brown, Jennifer; Raychaudhury, Somak; Forman, William; Donnelly, R. Hank; Jones, Christine

    2009-04-01

    We present the X-ray point-source population in the nearby Virgo elliptical galaxy NGC 4636 from three Chandra X-ray observations. These observations, totaling ~193 ks after time filtering, were taken with the Advanced CCD Imaging Camera (ACIS) over a three-year period. Using a wavelet decomposition detection algorithm, we detect 318 individual point sources. For our analysis, we use a subset of 277 detections with >= net 10 counts (a limiting luminosity of approximately 1.2 × 1037 erg s-1 in the 0.5-2 keV band, outside the central 1farcm5 bright galaxy core). We present a radial distribution of the point sources. Between 1farcm5 and 6' from the center, 25% of our sources are likely to be background sources (active galactic nuclei (AGNs)) and 75% are low-mass X-ray binaries (LMXBs) within the galaxy, while at radial distances greater than 6', background sources (AGN) will dominate the point sources. We explore short and long-term variability (over timescales of 1 day to three years) for X-ray point sources in this elliptical galaxy. 54 sources (24%) in the common ACIS fields of view show significant variability between observations. Of these, 37 are detected with at least 10 net counts in only one observation and thus may be "transient." In addition, ~10% of the sources in each observation show significant short-term variability; we present an example light curve for a variable bright source. The cumulative luminosity function (LF) for the point sources in NGC 4636 can be represented as a power law of slope α = 1.14 ± 0.03. We do not detect, but estimate an upper limit of ~4.5 × 1037 erg s-1 to the current X-ray luminosity of the historical supernova SN1939A. We find 77 matches between X-ray point sources and globular cluster (GC) candidates found in deep optical images of NGC 4636. In the annulus from 1farcm5 to 6' of the galaxy center, 48 of the 129 X-ray point sources (37%) with >=10 net counts are matched with GC candidates. Since we expect 25% of these

  4. Developing small vacuum spark as an x-ray source for calibration of an x-ray focusing crystal spectrometer

    SciTech Connect

    Ghomeishi, Mostafa; Adikan, Faisal Rafiq Mahamd; Karami, Mohammad

    2012-10-15

    A new technique of x-ray focusing crystal spectrometers' calibration is the desired result. For this purpose the spectrometer is designed to register radiated copper K{alpha} and K{beta} lines by using a flat {alpha}-quartz crystal. This experiment uses pre-breakdown x-ray emissions in low vacuum of about 2.5-3 mbar. At this pressure the pinch will not form so the plasma will not radiate. The anode material is copper and the capacity of the capacitor bank is 22.6 nF. This experiment designed and mounted a repetitive triggering system to save the operator time making hundreds of shots. This emission amount is good for calibration and geometrical adjustment of an optical crystal x-ray focusing spectrometer.

  5. Developing small vacuum spark as an x-ray source for calibration of an x-ray focusing crystal spectrometer.

    PubMed

    Ghomeishi, Mostafa; Karami, Mohammad; Adikan, Faisal Rafiq Mahamd

    2012-10-01

    A new technique of x-ray focusing crystal spectrometers' calibration is the desired result. For this purpose the spectrometer is designed to register radiated copper Kα and Kβ lines by using a flat α-quartz crystal. This experiment uses pre-breakdown x-ray emissions in low vacuum of about 2.5-3 mbar. At this pressure the pinch will not form so the plasma will not radiate. The anode material is copper and the capacity of the capacitor bank is 22.6 nF. This experiment designed and mounted a repetitive triggering system to save the operator time making hundreds of shots. This emission amount is good for calibration and geometrical adjustment of an optical crystal x-ray focusing spectrometer. PMID:23126754

  6. NuSTAR results on Ultra-Luminous X-ray sources: black holes or neutron stars?

    NASA Astrophysics Data System (ADS)

    Fuerst, Felix

    2015-04-01

    Ultraluminous X-ray sources (ULXs) are extremely bright, off-nuclear point sources in nearby galaxies. The only process known to power them is a very high accretion rate onto a compact object. If the compact object is similar to those observed in our own galaxy, i.e., a standard stellar remnant, the accretion rate has to exceed the Eddington rate by a factor of 10-100 in a so-called super-Eddington accretion regime. If on the other hand the compact were more massive, ULXs would be the only known evidence for intermediate mass black holes with masses of 100's or 1000's solar masses. Broadband spectral studies of a sample of ULXs, making full use of the hard X-ray sensitivity of the Nuclear Spectroscopic Telescope Array (NuSTAR), are suggestive of super-Eddington accretion. A definitive answer has, however, not yet been reached owing to continued difficulty constraining ULX masses. I will report on recent, multi-epoch NuSTAR observations, which allow us to examine the evolution of these enigmatic sources and their accretion process by studying their time variability and hard X-ray spectrum above 10keV. In a surprising discovery we have recently shown that the ULX M82 X-2 harbors a neutron star, the first evidence for a neutron star in a ULX. I will discuss possible modes of super-Eddington accretion on neutron stars and compare M82 X-2 to known accreting neutron stars in our galaxy. On behalf of the NuSTAR ULX science team led by Fiona Harrison.

  7. Exploring a New Population of Compact Objects: X-ray and IR Observations of the Galactic Centre

    NASA Astrophysics Data System (ADS)

    Bandyopadhyay, Reba M.; Gosling, Andrew J.; Eikenberry, Stephen E.; Muno, Michael P.; Blundell, Katherine M.; Podsiadlowski, Philipp; Mikles, Valerie J.; Dewitt, Curtis

    2008-10-01

    I describe the IR and X-ray observational campaign we have undertaken for the purpose of determining the nature of the faint discrete X-ray source population discovered by Chandra in the Galactic Center (GC). Data obtained for this project includes a deep Chandra survey of the Galactic Bulge; deep, high resolution IR imaging from VLT/ISAAC, CTIO/ISPI, and the UKIDSS Galactic Plane Survey (GPS) and IR spectroscopy from VLT/ISAAC and IRTF/SpeX. By cross-correlating the GC X-ray imaging from Chandra with our IR surveys, we identify candidate counterparts to the X-ray sources via astrometry. Using a detailed IR extinction map, we are deriving magnitudes and colors for all the candidates. Having thus established a target list, we will use the multi-object IR spectrograph FLAMINGOS-2 on Gemini-South to carry out a spectroscopic survey of the candidate counterparts, to search for emission line signatures which are a hallmark of accreting binaries. By determining the nature of these X-ray sources, this FLAMINGOS-2 Galactic Center Survey will have a dramatic impact on our knowledge of the Galactic accreting binary population.

  8. X-ray source considerations in operation of digital detector arrays

    SciTech Connect

    Jensen, Terrence; Wendt, Scott

    2014-02-18

    Digital Detector Arrays (DDA) are increasingly replacing film in radiography applications. Standards exist for characterizing the performance of these detectors, and for using them in specific inspections. We have observed that the selection of the x-ray source to use with these detectors can also have a significant influence on the performance. We look at differences between standard, and micro-focus x-ray tubes, and end-window vs. side-window micro-focus tubes. We find that for best results, one must calibrate the DDA for the source settings used during an inspection. This is particularly true for variable-focus sources.

  9. X-ray grating interferometry with a liquid-metal-jet source

    SciTech Connect

    Thüring, T.; Rutishauser, S.; Stampanoni, M.; Zhou, T.; Lundström, U.; Burvall, A.; Hertz, H. M.; David, C.

    2013-08-26

    A liquid-metal-jet X-ray tube is used in an X-ray phase-contrast microscope based on a Talbot type grating interferometer. With a focal spot size in the range of a few microns and a photon flux of ∼10{sup 12} photons/s×sr, the brightness of such a source is approximately one order of magnitude higher than for a conventional microfocus source. For comparison, a standard microfocus source was used with the same grating interferometer, showing significantly increased visibility for the liquid-metal-jet arrangement. Together with the increased flux, this results in improved signal-to-noise ratio.

  10. Towards graphene plasmon-based free-electron infrared to X-ray sources

    NASA Astrophysics Data System (ADS)

    Wong, Liang Jie; Kaminer, Ido; Ilic, Ognjen; Joannopoulos, John D.; Soljačić, Marin

    2016-01-01

    Rapid progress in nanofabrication methods has fuelled a quest for ultra-compact photonic integrated systems and nanoscale light sources. The prospect of small-footprint, high-quality emitters of short-wavelength radiation is especially exciting due to the importance of extreme-ultraviolet and X-ray radiation as research and diagnostic tools in medicine, engineering and the natural sciences. Here, we propose a highly directional, tunable and monochromatic radiation source based on electrons interacting with graphene plasmons. Our complementary analytical theory and ab initio simulations demonstrate that the high momentum of the strongly confined graphene plasmons enables the generation of high-frequency radiation from relatively low-energy electrons, bypassing the need for lengthy electron acceleration stages or extreme laser intensities. For instance, highly directional 20 keV photons could be generated in a table-top design using electrons from conventional radiofrequency electron guns. The conductive nature and high damage threshold of graphene make it especially suitable for this application. Our electron-plasmon scattering theory is readily extended to other systems in which free electrons interact with surface waves.

  11. Microfocus x-ray imaging of traceable pointlike {sup 22}Na sources for quality control

    SciTech Connect

    Hasegawa, T.; Oda, K.; Sato, Y.; Ito, H.; Masuda, S.; Yamada, T.; Matsumoto, M.; Murayama, H.; Takei, H.

    2012-07-15

    Purpose: The purpose of this study is to propose a microfocus x-ray imaging technique for observing the internal structure of small radioactive sources and evaluating geometrical errors quantitatively, and to apply this technique to traceable pointlike {sup 22}Na sources, which were designed for positron emission tomography calibration, for the purpose of quality control of the pointlike sources. Methods: A microfocus x-ray imaging system with a focus size of 0.001 mm was used to obtain projection x-ray images and x-ray CT images of five pointlike source samples, which were manufactured during 2009-2012. The obtained projection and tomographic images were used to observe the internal structure and evaluate geometrical errors quantitatively. Monte Carlo simulation was used to evaluate the effect of possible geometrical errors on the intensity and uniformity of 0.511 MeV annihilation photon pairs emitted from the sources. Results: Geometrical errors were evaluated with sufficient precision using projection x-ray images. CT images were used for observing the internal structure intuitively. As a result, four of the five examined samples were within the tolerance to maintain the total uncertainty below {+-}0.5%, given the source radioactivity; however, one sample was found to be defective. Conclusions: This quality control procedure is crucial and offers an important basis for using the pointlike {sup 22}Na source as a basic calibration tool. The microfocus x-ray imaging approach is a promising technique for visual and quantitative evaluation of the internal geometry of small radioactive sources.

  12. Seeing Red and Shooting Blanks: Study of Red Quasars and Blank X-Ray Sources

    NASA Technical Reports Server (NTRS)

    Oliversen, Ronald (Technical Monitor); Elvis, Martin

    2005-01-01

    A major paper describing the technique and providing a list of 'blanks' was published in the Astrophysical Journal (abstract below). The results revealed a fascinating trove of novel X-ray sources: high redshift clusters of galaxies found efficiently; X-ray absorbed, optically clean AGN, which may be the bright prototypes of Chandra Deep Survey sources; and several with a still unknown nature. Recent XMM-Newton results confirm the existence of this class of X-ray source with much refined positions. During the first year of this project we have made a major discovery. The second 'blanks' X-ray source observed with Chandra was found to be extended. Using Chandra data and ground-based R and K band imaging we estimated this to be a high redshift cluster of galaxies with z approx. 0.85. Spectroscopy agrees with this estimate (z=0.89). This success shows that our method of hunting down 'blank' field X-ray sources is a highly efficient method of finding the otherwise elusive high redshift clusters. With extensive follow-up we should be able to use 'blanks' to make cosmological tests. The paper is now in press in the Astrophysical Journal (abstract below.) The other Chandra source is point-like, showing that there are a variety of 'blank' source types. Other follow-up observations with XMM-Newton, and (newly approved in cycle 2) with Chandra are eagerly awaited. A follow-up paper uses a large amount of supporting data for the remaining blanks. A combination of ROSAT, Chandra and ground based data convincingly identified one of the blanks as a Ultra-luminous X-ray source (ULX) in a spiral galaxy (abstract below). This program resulted in 3 refereed papers in major journals, 4 conference proceedings and a significant fraction of the PhD thesis of Dr. Ilaria Cagnoni. Details of the publications are given.

  13. High speed x-ray beam chopper

    DOEpatents

    McPherson, Armon; Mills, Dennis M.

    2002-01-01

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

  14. Milliarcsec-scale radio emission of ultraluminous X-ray sources: steady jet emission from an intermediate-mass black hole?

    NASA Astrophysics Data System (ADS)

    Mezcua, M.; Farrell, S. A.; Gladstone, J. C.; Lobanov, A. P.

    2013-12-01

    The origin of the high X-ray luminosities of most ultraluminous X-ray sources (ULXs) still remains poorly understood. Most of the scenarios proposed to explain their nature assume that ULXs are powered by accretion on to a black hole (BH). In this case, the detection of compact radio emission and the location of the ULXs in the Fundamental Plane (X-ray versus radio-luminosity plane) can provide an estimate of the ULX BH mass and help address the question of their physical nature. We present the results of a high-resolution (very long baseline interferometry) radio observational campaign aimed at detecting and studying compact radio emission in four ULXs with known radio counterparts. We find that one of the targets (N4559-X4) was previously misclassified: its low X-ray luminosity indicates that the source is not a ULX. No milliarcsec-scale radio emission is detected for N4559-X4 nor for the ULXs N4490-X1 and N5194-X2, for which upper limits on the radio luminosities are estimated. These limits argue strongly against the presence of supermassive BHs in these three systems. For N4559-X4, the low X-ray luminosity and the ratio of the radio and X-ray luminosities suggest the presence of an X-ray binary. Compact radio emission is detected for the ULX N5457-X9 within its Chandra positional error, making N5457-X9 a potential intermediate-mass BH with steady jet emission.

  15. Predicting the coherent X-ray wavefront focal properties at the Linac Coherent Light Source (LCLS) X-ray free electron laser.

    PubMed

    Barty, Anton; Soufli, Regina; McCarville, Tom; Baker, Sherry L; Pivovaroff, Michael J; Stefan, Peter; Bionta, Richard

    2009-08-31

    The first X-ray free electron laser (XFEL) at keV energies will be the Linac Coherent Light Source (LCLS), located at the SLAC National Accelerator Laboratory. Scheduled to begin operation in 2009, this first-of-a-kind X-ray source will produce ultra-short X-ray pulses of unprecedented brightness in the 0.8 to 8 keV first harmonic photon energy regime. Much effort has been invested in predicting and modeling the XFEL photon source properties at the undulator exit; however, as most LCLS experiments are ultimately dependent on the beam focal spot properties it is equally as important to understand the XFEL beam at the endstations where the experiments are performed. Here, we use newly available precision surface metrology data from actual LCLS mirrors combined with a scalar diffraction model to predict the LCLS beam properties in the experiment chambers.

  16. Predicting the coherent X-ray wavefront focal properties at the Linac Coherent Light Source (LCLS) X-ray free electron laser.

    PubMed

    Barty, Anton; Soufli, Regina; McCarville, Tom; Baker, Sherry L; Pivovaroff, Michael J; Stefan, Peter; Bionta, Richard

    2009-08-31

    The first X-ray free electron laser (XFEL) at keV energies will be the Linac Coherent Light Source (LCLS), located at the SLAC National Accelerator Laboratory. Scheduled to begin operation in 2009, this first-of-a-kind X-ray source will produce ultra-short X-ray pulses of unprecedented brightness in the 0.8 to 8 keV first harmonic photon energy regime. Much effort has been invested in predicting and modeling the XFEL photon source properties at the undulator exit; however, as most LCLS experiments are ultimately dependent on the beam focal spot properties it is equally as important to understand the XFEL beam at the endstations where the experiments are performed. Here, we use newly available precision surface metrology data from actual LCLS mirrors combined with a scalar diffraction model to predict the LCLS beam properties in the experiment chambers. PMID:19724548

  17. Multiwavelength Study of the Bright X-ray Source Population in the Interacting Galaxies NGC 5774/NGC 5775

    NASA Technical Reports Server (NTRS)

    Ghosh, Kajal K.; Swartz, Douglas A.; Tennant, Allyn F.; Saripalli, Lakshmi; Gandhi, Poshak; Foellmi, Cedric; Gutierrez, Carlos M.; Lopez-Corredoira, Martin

    2006-01-01

    The X-ray source population in the field of the interacting pair of galaxies NGC 5774/5775 is reported. A total of 49 discrete sources are detected, including 12 ultraluminous X-ray source candidates with lum inosities above 10(exp 39)erg/s in the 0.5 - 8.0 keV X-ray band. Several of these latter are transient X-ray sources that fall below detect ion levels in one of two X-ray observations spaced 15 months apart. X-ray source positions are mapped onto optical and radio images to sear ch for potential counterparts. Eleven sources have optically-bright c ounterparts. Optical colors are used to differentiate these sources, which are mostly located outside the optical extent of the interacting galaxies, as potential globular clusters (3 sources) and quasars (5) . Follow-up optical spectroscopy confirms two of the latter are background quasars.

  18. Observations of the X-ray burst source MXB 1636-53

    NASA Technical Reports Server (NTRS)

    Hoffman, J. A.; Lewin, W. H. G.; Doty, J.

    1977-01-01

    X-ray bursts have been observed from MXB 1636-53, almost certainly associated with the strong steady X-ray source 2S 1636-536 (Norma X-1, 3U 1636-53). The steady source was observed in January 1977 at roughly half the intensity reported in the 3U catalog and showed about 15% variability on a time scale of hours. The spectra of the X-ray bursts are well fitted by blackbody radiation whose temperature rises rapidly to a maximum of approximately 28 million K and then cools slowly. If the source is at a distance of 10 kpc, the radius of the projected burst emission region is about 10 km, similar to the size of a neutron star.

  19. X-ray Sources in the RCrA Dark Cloud Complex

    NASA Astrophysics Data System (ADS)

    Garmire, Gordon; Garmire, Audrey

    2002-04-01

    The RCrA Dark Cloud Complex was observed by the Chandra X-ray Observatory on 7 October 2000 for 19706 s using the ACIS-I array in faint mode. The image covers 286 sq. arc min centered on the Coronet Cluster, the thckest part of the Dark Cloud. A total of 102 X-ray point sources were detected above a threshold of 7x10**(-16) ergs/cm^2/s in the 0.4 - 8.0 keV band assuming a Raymond and Smith plasma with a temperature of 6.7 M deg and Solar abundance. About one third are identified with cataloged optical and infrared sources with 14% detected only in the infrared. X-ray Spectra of the brightest 10 sources will be presented. A comparison with other young stellar complexes will be made.

  20. Influence of Bernstein modes on the efficiency of electron cyclotron resonance x-ray source

    SciTech Connect

    Andreev, V. V.; Nikitin, G.V.; Savanovich, V.Yu.; Umnov, A.M.; Elizarov, L.I.; Serebrennikov, K.S.; Vostrikova, E.A.

    2006-03-15

    The article considers the factors influencing the temperature of hot electron component in an electron cyclotron resonance (ECR) x-ray source. In such sources the electron heating occurs often due to extraordinary electromagnetic wave propagating perpendicularly to the magnetic field. In this case the possibility of the absorption of Bernstein modes is regarded as an additional mechanism of electron heating. The Bernstein modes in an ECR x-ray source can arise due to either linear transformation or parametric instability of external transversal wave. The article briefly reviews also the further experiments which will be carried out to study the influence of Bernstein modes on the increase of hot electron temperature and consequently of x-ray emission.

  1. Positions of galactic X-ray sources - Galactic longitude between 20 and 55 deg

    NASA Technical Reports Server (NTRS)

    Doxsey, R. E.; Bradt, H. V.; Dower, R. G.; Jernigan, J. G.; Apparao, K. M. V.

    1977-01-01

    Precise positions, determined with data from the SAS-3 X-ray observatory, are presented for eight galactic plane X-ray sources (Aql X-1, Ser X-1, 3U 1956+11, 3U 1822-00, 3U 1915-05, A 1845-02, A 1850-08, A 1905+00). Error radii for the positions range from 20 to 50 arc s. Previously proposed optical identifications of three of the sources (Ser X-1, 3U 1956+11, A 1850-08) are supported by these results. Three (Ser X-1, A 1905+00, 3U 1915-05) have been identified as X-ray burst sources.

  2. A compact Laboratory Transmission X-ray Microscope for the water window

    NASA Astrophysics Data System (ADS)

    Legall, H.; Stiel, H.; Blobel, G.; Seim, C.; Baumann, J.; Yulin, S.; Esser, D.; Hoefer, M.; Wiesemann, U.; Wirtz, M.; Schneider, G.; Rehbein, S.; Hertz, H. M.

    2013-10-01

    In the water window (2.2 - 4.4 nm) the attenuation of radiation in water is significantly smaller than in organic material. Therefore, intact biological specimen (e.g. cells) can be investigated in their natural environment. In order to make this technique accessible to users in a laboratory environment a Full-Field Laboratory Transmission X-ray Microscope (L-TXM) has been developed. The L-TXM is operated with a nitrogen laser plasma source employing an InnoSlab high power laser system for plasma generation. For microscopy the Lyα emission of highly ionized nitrogen at 2.48 nm is used. A laser plasma brightness of 5 × 1011 photons/(s × sr × μm2 in line at 2.48 nm) at a laser power of 70 W is demonstrated. In combination with a state-of-the-art Cr/V multilayer condenser mirror the sample is illuminated with 106 photons/(μm2 × s). Using objective zone plates 35 - 40 nm lines can be resolved with exposure times < 60 s. The exposure time can be further reduced to 20 s by the use of new multilayer condenser optics and operating the laser at its full power of 130 W. These exposure times enable cryo tomography in a laboratory environment.

  3. Calibration of a compact XUV soft X-ray monochromator with a digital autocollimator in situ.

    PubMed

    Yuh, Jih Young; Lin, Shang Wei; Huang, Liang Jen; Lee, Long Life

    2016-09-01

    A digital autocollimator of resolution 0.1 µrad (0.02 arcsec) serves as a handy correction tool for calibrating the angular uncertainty during angular and lateral movements of gratings inside a monochromator chamber under ultra-high vacuum. The photon energy dispersed from the extreme ultraviolet (XUV) to the soft X-ray region of the synchrotron beamline at the Taiwan Light Source was monitored using molecular ionization spectra at high resolution as energy references that correlate with the fine angular steps during grating rotation. The angular resolution of the scanning mechanism was <0.3 µrad, which results in an energy shift of 80 meV at 867 eV. The angular uncertainties caused by the lateral movement during a grating exchange were decreased from 2.2 µrad to 0.1 µrad after correction. The proposed method provides a simple solution for on-site beamline diagnostics of highly precise multi-axis optical manipulating instruments at synchrotron facilities and in-house laboratories. PMID:27577780

  4. Calibration of a compact XUV soft X-ray monochromator with a digital autocollimator in situ.

    PubMed

    Yuh, Jih Young; Lin, Shang Wei; Huang, Liang Jen; Lee, Long Life

    2016-09-01

    A digital autocollimator of resolution 0.1 µrad (0.02 arcsec) serves as a handy correction tool for calibrating the angular uncertainty during angular and lateral movements of gratings inside a monochromator chamber under ultra-high vacuum. The photon energy dispersed from the extreme ultraviolet (XUV) to the soft X-ray region of the synchrotron beamline at the Taiwan Light Source was monitored using molecular ionization spectra at high resolution as energy references that correlate with the fine angular steps during grating rotation. The angular resolution of the scanning mechanism was <0.3 µrad, which results in an energy shift of 80 meV at 867 eV. The angular uncertainties caused by the lateral movement during a grating exchange were decreased from 2.2 µrad to 0.1 µrad after correction. The proposed method provides a simple solution for on-site beamline diagnostics of highly precise multi-axis optical manipulating instruments at synchrotron facilities and in-house laboratories.

  5. On the origin of two unidentified radio/X-ray sources discovered with XMM-Newton

    NASA Astrophysics Data System (ADS)

    García, Federico; Combi, Jorge A.; Medina, María C.; Romero, Gustavo E.

    2015-12-01

    Aims: We aim at clarifying the nature of the emission of two spatially related unidentified X-ray sources detected with XMM-Newton telescope at intermediate-low Galactic latitude Methods: We use the imaging and spectral capabilities of XMM-Newton to study the X-ray properties of these two sources. In addition, we complement our study with radio data obtained at different frequencies to analyze a possible physical association between the sources. Results: Observations reveal a point-like source aligned with elongated diffuse emission. The X-ray spectra of these sources is best-fitted by an absorbed power law with photon index Γ ~ 1.7 for the point-like source and ~2.0 for the extended source. Both sources show nonthermal radio-continuum counterparts that might indicate a physical association. In addition, from the available data, we did not detect variability on the point-like source in several timescales. Two possible scenarios are analyzed: one Galactic and one extra-Galactic. First, based on HI line absorption, assuming a Galactic origin, we infer a distance upper bound of ≲2 kpc, which poses a constraint on the height over the Galactic plane of ≲200 pc and on the linear size of the system of ≲2.3 pc. In this case, the X-ray luminosities are ≳1032 erg s-1 and ≳7.5 × 1032 erg s-1, for the point-like and extended sources, respectively. Second, an extra-Galactic nature is discussed, where the point-like source might be the core of a radio galaxy and the extended source its lobe. In this case, we compare derived fluxes, spectral indices, and spatial correlation with those typical from the radio galaxy population, showing the feasibility of this alternative astrophysical scenario. Conclusions: From the available observational evidence, we suggest that the most promising scenario to explain the nature of these sources is a system consisting of a one-sided radio galaxy, where the point-like source is an active galactic nucleus and the extended source

  6. Observations of transient and anomalous x-ray pulsars with the burst and transient source experiment and the Rossi x-ray timing explorer

    NASA Astrophysics Data System (ADS)

    Wilson-Hodge, Colleen Anne

    1999-11-01

    The Burst and Transient Source Experiment (BATSE) on the Compton Gamma-Ray Observatory and the Rossi X-ray Timing Explorer (RXTE) allow unprecedented studies of X- ray pulsars. The first part of this dissertation describes the capabilities for X-ray observations with BATSE and RXTE and X-ray timing and source detection techniques, which are applied to five transient X-ray pulsars in the second part of this dissertation. Observations of the 12.3-s pulsar GS 0834- 430 discovered that it is in a 105.8 +/- 0.4-day orbit with a small, but non-zero, eccentricity. GS 0834- 430 underwent nine normal (LX ~ 3 × 1037 erg s-1) periodic X-ray outbursts, spaced at the orbital period; however, the last two outbursts were unevenly spaced. No other known systems exhibit these shifted outbursts. The 198-s pulsar GRO J2058+42, which was discovered with BATSE during a giant ( LX ~ 3 × 1038 erg s-1 ) outburst in 1995, underwent a series of nine outbursts alternating in 20-50 keV pulsed intensity every ~55 days, suggesting a ~110-day outburst cycle, however, the 2-10 keV intensities did not show this alternating behavior. If the outburst cycle corresponds to the orbital period, two outbursts are occurring each orbit, near periastron and apastron. Cep X-4, a 66.3-s Be/X-ray pulsar, was detected in two normal outbursts in 1993 and 1997. If all outbursts of Cep X-4 are assumed to occur at the same orbital phase, the orbital period is 23 days <~ Porb <~ 147.3 days. A 1118-616, a 405-s Be/X- ray pulsar, underwent a 65-day giant outburst comprising three peaks, spaced by ~22 days. The 293-s Be/X-ray pulsar, 4U 1145-619, underwent 12 outbursts occurring every 186.68 +/- 0.05 days, which varied widely in intensity and duration, with no clear distinction between giant and normal outbursts. The third part of this dissertation presents results on an 8.7-s anomalous X-ray pulsar (AXP), 4U 0142+61. An orbital period search yielded an upper limit on the semi-major axis a x sin i <~ 0.26 lt-s for

  7. A Possible X-Ray and Radio Counterpart of the High-Energy Gamma-Ray Source 3EG J2227+6122

    NASA Technical Reports Server (NTRS)

    Halpern, Jules P.; Gotthelf, E. V.; Helfand, D. J.; Leighly, K. M.; Oliversen, Ronald (Technical Monitor)

    2001-01-01

    The identity of the persistent EGRET sources in the Galactic plane is largely a mystery. For one of these, 3EG J2227+6122, our complete census of X-ray and radio sources in its error circle reveals a remarkable superposition of an incomplete radio shell with a flat radio spectrum, and a compact, power-law X-ray source with photon index Gamma = 1.5 and with no obvious optical counterpart. The radio shell is polarized at a level of approx. = 25%. The anomalous properties of the radio source prevent us from deriving a completely satisfactory theory as to its nature. Nevertheless, using data from ROSAT, ASCA, the VLA, and optical imaging and spectroscopy, we argue that the X-ray source may be a young pulsar with an associated wind-blown bubble or bow shock nebula, and an example of the class of radio-quiet pulsars which are hypothesized to comprise the majority of EGRET sources in the Galaxy. The distance to this source can be estimated from its X-ray absorption as 3 kpc. At this distance, the X-ray and gamma-ray luminosities would be approx. = 1.7 x 10(exp 33) and approx. = 3.7 x 10(exp 35) erg/s, respectively, which would require an energetic pulsar to power them. If, on the contrary, this X-ray source is not the counterpart of 3EG J2227+6122, then by process of elimination the X-ray luminosity of the latter must be less than 10(exp -4) of its gamma-ray luminosity, a condition not satisfied by any established class of gamma-ray source counterpart. This would require the existence of at least a quantitatively new type of EGRET source, as has been suggested in studies of other EGRET fields.

  8. Time Resolved X-ray Magnetic Circular Dichroism at the Linac Coherent Light Source

    NASA Astrophysics Data System (ADS)

    Schlotter, W.; Higley, D.; Jal, E.; Dakovski, G.; Yuan, E.; MacArthur, J.; Lutman, A.; Hirsch, K.; Granitzka, P.; Chen, Z.; Coslovich, G.; Hoffman, M.; Mitra, A.; Reid, A.; Hart, P.; Nuhn, H.-D.; Duerr, H.; Arenholz, E.; Shafer, P.; Dennes, P.; Joseph, J.; Guyader, L.; Tsukamoto, A.

    We demonstrate ultrafast time resolved X-ray Magnetic Circular Dichroism on optically switchable GdFeCo thin film samples. This method extends the element specificity of time resolved x-ray absorption spectroscopy to characterize the evolution of electron spin and orbital angular momenta. These measurements were enabled by a recent upgrade at the Linac Coherent Light Source (LCLS) to generate circularly polarized x-rays. Additionally these measurements were enhanced by new detection systems that benefit all x-ray absorption spectroscopy experiments performed in transmission. Consequently static XMCD data are in excellent agreement with similar measurements at synchrotron light sources. The LCLS is an x-ray free electron laser user facility accessible via a peer-reviewed proposal process. Acknowledgement: The Linac Coherent Light Source (LCLS), SLAC National Accelerator Laboratory, is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Contract No. DE-AC02-76SF00515.

  9. ON THE NATURE OF HARD X-RAY EXTRAGALACTIC SOURCES OBSERVED WITH XMM-NEWTON

    SciTech Connect

    Jimenez-Bailon, E.; Huerta, E. M.; Krongold, Y.; Chavushyan, V.; Schartel, N.; Santos-Lleo, M.

    2012-03-15

    Over the last decade, X-ray surveys have provided outstanding new results due to the lack of the common selection effects present at other wavelengths. Here, we have selected a sample of unidentified sources from the XMM-Newton Slew Survey Catalog, likely to be extragalactic. Five of them were observed with the XMM-Newton observatory. In this work, we present the results of the spectral analysis of these objects in the X-ray and optical bands. Only three of them had useful spectroscopic X-ray data, and follow up observations were carried out in the optical range to determine their coordinates, classification, and redshift. The sources are different types of active galactic nuclei (AGNs) with redshifts ranging from 0.059 to 0.386. The properties at both spectral ranges (X-rays and optical) are compatible with the common properties of their types of AGNs. Although the sources were selected by their hard X-ray properties, none of the three detected objects turned out to be an obscured AGN.

  10. Ultrabright multikilovolt coherent tunable x-ray source at lambda ~ 2.71 2.93 Å

    NASA Astrophysics Data System (ADS)

    Borisov, Alex B.; Song, Xiangyang; Frigeni, Fabrizio; Koshman, Yevgeniya; Dai, Yang; Boyer, Keith; Rhodes, Charles K.

    2003-08-01

    Detailed molecular structural information of the living state is of enormous significance to the medical and biological communities. Since hydrated biologically active structures are small delicate complex three-dimensional (3D) entities, it is essential to have molecular scale spatial resolution, high contrast, distortionless, direct 3D modalities of visualization of naturally functioning specimens in order to faithfully reveal their full molecular architectures. An x-ray holographic microscope equipped with an x-ray laser as the illuminator would be uniquely capable of providing these images. A quantitative interlocking concordance of physical evidence, that includes (a) the observation of strong enhancement of selected spectral components of several Xeq+ hollow-atom transition arrays (q = 31, 32, 34, 35, 36, 37) radiated axially from confined plasma channels, (b) the measurement of line narrowing that is spectrally correlated with the amplified transitions, (c) evidence for spectral hole-burning in the spontaneous emission, a manifestation of saturated amplification, that corresponds spectrally with the amplified lines, and (d) the detection of an intense narrow (deltathetax ~ 0.2 mrad) directed beam of radiation, (1) experimentally demonstrates in the lambda ~ = 2.71-2.93 Å range (hbaromegax ~ = 4230-4570 eV) the operation of a new concept capable of producing the ideal conditions for amplification of multikilovolt x-rays and (2) proves the feasibility of a compact x-ray illuminator that can cost-effectively achieve the mission of biological x-ray microholography. The measurements also (alpha) establish the property of tunability in the quantum energy over a substantial fraction of the spectral region exhibiting amplification (Deltahbaromegax ~ 345 eV) and (beta) demonstrate the coherence of the x-ray output through the observation of a canonical spatial mode pattern. An analysis of the physical scaling revealed by these results indicates that the capability

  11. QUANTITATIVE HOMOGENEITY AND IN-CONTACT PARTICLES OF HIGH TEMPERATURE REACTORS (HTR) COMPACTS DETERMINATION VIA X-RAY TOMOGRAPHY

    SciTech Connect

    Lecomte, G.; Letang, J. M.; Tisseur, D.; Banchet, J.; Vitali, M. P.

    2008-02-28

    In AREVA Nuclear Power's High Temperature Reactor (HTR) design called ANTARES, fuel consists of compacts composed of few thousands millimetric quasi-spherical particles dispersed in a graphite matrix. Compact homogeneity, defined as the homogeneous particles spatial distribution in the matrix, as well as the possibility of obtaining particles in contact, need to be assessed since they condition the thermo-mechanical behavior of the nuclear fuel under irradiation. In this paper, image and data processing algorithms are developed to do so, based on X-Ray tomographic images.

  12. The Galactic plane at faint X-ray fluxes - II. Stacked X-ray spectra of a sample of serendipitous XMM-Newton sources

    NASA Astrophysics Data System (ADS)

    Warwick, R. S.; Byckling, K.; Pérez-Ramírez, D.

    2014-03-01

    We have investigated the X-ray spectral properties of a sample of 138 X-ray sources detected serendipitously in XMM-Newton observations of the Galactic plane, at an intermediate to faint flux level. We divide our sample into five subgroups according to the spectral hardness of the sources, and stack (i.e. co-add) the individual source spectra within each subgroup. As expected these stacked spectra show a softening trend from the hardest to the softest subgroups, which is reflected in the inferred line-of-sight column density. The spectra of the three hardest subgroups are characterized by a hard continuum plus superimposed Fe-line emission in the 6-7 keV bandpass. The average equivalent width (EW) of the 6.7-keV He-like Fe Kα line is 170^{+35}_{-32} eV, whereas the 6.4-keV Fe K fluorescence line from neutral iron and the 6.9-keV H-like Fe Lyα line have EWs of 89^{+26}_{-25} and 81^{+30}_{-29} eV, respectively, i.e. roughly half that of the 6.7-keV line. The remaining subgroups exhibit soft thermal spectra. Virtually all of the spectrally soft X-ray sources can be associated with relatively nearby coronally active late-type stars, which are evident as bright near-infrared (NIR) objects within the X-ray error circles. On a similar basis only a minority of the spectrally hard X-ray sources have likely NIR identifications. The average continuum and Fe-line properties of the spectrally hard sources are consistent with those of magnetic cataclysmic variables but the direct identification of large numbers of such systems in Galactic X-ray surveys, probing intermediate to faint flux levels, remains challenging.

  13. Flat Field Anomalies in an X-ray CCD Camera Measured Using a Manson X-ray Source (HTPD 08 paper)

    SciTech Connect

    Haugh, M; Schneider, M B

    2008-04-28

    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 {micro}m square pixels, and 15 {micro}m 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/{Delta}E {approx} 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.

  14. THE EFFECT OF SATELLITE LINES FROM THE 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. EPA has been using crystallite size and strain data obtained from x-ray diffraction (XRD) peak profile analysis to predic...

  15. X-ray micro-Tomography at the Advanced Light Source

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The X-ray micro-Tomography Facility at the Advanced Light Source has been in operation since 2004. The source is a superconducting bend magnet of critical energy 10.5KeV; photon energy coverage is 8-45 KeV in monochromatic mode, and a filtered white light option yields useful photons up to 50 KeV. A...

  16. X-ray spectra from the Cornell Electron-Beam Ion Source (CEBIS I)

    SciTech Connect

    Johnson, B.M.; Jones, K.W.; Kostroun, V.O.; Ghanbari, E.; Janson, S.W.

    1985-01-01

    Radiation emitted from the Cornell electron beam ion source (CEBIS I) has been surveyed with a Si(Li) x-ray detector. These spectra can be used to estimate backgrounds from electron bremsstrahlung and to evaluate the feasibility of atomic physics experiments using the CEBIS I source in this configuration. 1 ref., 2 figs.

  17. Integral field spectroscopy of the ultraluminous X-ray source Holmberg II X-1

    NASA Astrophysics Data System (ADS)

    Lehmann, I.; Becker, T.; Fabrika, S.; Roth, M.; Miyaji, T.; Afanasiev, V.; Sholukhova, O.; Sánchez, S. F.; Greiner, J.; Hasinger, G.; Costantini, E.; Surkov, A.; Burenkov, A.

    2005-03-01

    We present optical integral field observations of the H II region containing the ultraluminous X-ray source Holmberg II X-1. We confirm the existence of an X-ray ionized nebula as the counterpart of the source owing to the detection of an extended He II λ4686 region (21× 47 pc) at the Chandra ACIS-S position. An extended blue object with a size of 11× 14 pc is coincident with the X-ray/He II λ4686 region, which could indicate that it is either a young stellar complex or a cluster. We have derived an X-ray to optical luminosity ratio of L_X/LB≥170, and presumable it is L_X/LB˜300{-}400 using the recent HST ACS data. We find a complex velocity dispersion at the position of the ULX. In addition, there is a radial velocity variation in the X-ray ionized region found in the He II emission of ±50 km s-1 on spatial scales of 2 3primeprime. We believe that the putative black hole not only ionizes the surrounding HII gas, but also perturbs it dynamically (via jets or the accretion disk wind). The spatial analysis of the public Chandra ACIS-S data reveals a point-like X-ray source and gives marginal indication of an extended component (ll15% of the total flux). The XMM-Newton EPIC-PN spectrum of HoII X-1 is best fitted with an absorbed power law in addition to either a thermal thick plasma or a thermal thin plasma or a multi-colour disk black body (MCD). In all cases, the thermal component shows a relatively low temperature (kT˜0.14{-}0.22 keV). Finally we discuss the optical/X-ray properties of HoII X-1 with regards to the possible nature of the source. The existence of an X-ray ionized nebula coincident with the ULX and the soft X-ray component with a cool accretion disk favours the interpretation as an intermediate-mass black hole (IMBH). However, the complex velocity behaviour at the position of the ULX indicates a dynamical influence of the black hole on the local HII gas.

  18. Copernicus observations of a number of galactic X-ray sources

    NASA Technical Reports Server (NTRS)

    Culhane, J. L.; Mason, K. O.; Sanford, P. W.; White, N. E.

    1976-01-01

    The Copernicus satellite was launched on 21 August 1972. The main experiment on board is the University of Princeton UV telescope. In addition a cosmic X-ray package of somewhat modest aperture was provided by the Mullard Space Science Laboratory (MSSL) of University College London. Following a brief description of the instrument, a list of galactic sources observed during the year is presented. Although the X-ray detection aperture is small, the ability to point the satellite for long periods of time with high accuracy makes Copernicus an ideal vehicle for the study of variable sources.

  19. A STATE TRANSITION OF THE LUMINOUS X-RAY BINARY IN THE LOW-METALLICITY BLUE COMPACT DWARF GALAXY I Zw 18

    SciTech Connect

    Kaaret, Philip; Feng Hua

    2013-06-10

    We present a measurement of the X-ray spectrum of the luminous X-ray binary in I Zw 18, the blue compact dwarf galaxy with the lowest known metallicity. We find the highest flux yet observed, corresponding to an intrinsic luminosity near 1 Multiplication-Sign 10{sup 40} erg s{sup -1} establishing it as an ultraluminous X-ray source (ULX). The energy spectrum is dominated by disk emission with a weak or absent Compton component and there is no significant timing noise; both are indicative of the thermal state of stellar-mass black hole X-ray binaries and inconsistent with the Compton-dominated state typical of most ULX spectra. A previous measurement of the X-ray spectrum shows a harder spectrum that is well described by a power law. Thus, the binary appears to exhibit spectral states similar to those observed from stellar-mass black hole binaries. If the hard state occurs in the range of luminosities found for the hard state in stellar-mass black hole binaries, then the black hole mass must be at least 85 M{sub Sun }. Spectral fitting of the thermal state shows that disk luminosities for which thin disk models are expected to be valid are produced only for relatively high disk inclinations, {approx}> 60 Degree-Sign , and rapid black hole spins. We find a{sub *} > 0.98 and M > 154 M{sub Sun} for a disk inclination of 60 Degree-Sign . Higher inclinations produce higher masses and somewhat lower spins.

  20. Conceptual study of moderately coupled plasmas and experimental comparison of laboratory x-ray sources

    SciTech Connect

    Li, C.

    1993-12-01

    In this thesis the fundamental concepts of moderately coupled plasmas, for which 2{approx_lt}ln{Lambda}{sub b}{approx_lt}10, are, for the first time, presented. This investigation is motivated because neither the conventional Fokker-Planck approximation [for weakly coupled plasmas (ln{Lambda}{sub b}{approx_lt}10)] nor the theory of dielectric response with correlations for strongly coupled plasmas (ln{Lambda}{sub b}{approx_lt}1) has satisfactorily addressed this regime. Specifically, herein the standard Fokker-Planck operator for Coulomb collisions has been modified to include hitherto neglected terms that are directly associated with large-angle scattering. In addition a reduced electron-ion collision operator has been calculated that, for the first time, manifests 1/ln{Lambda}{sub b} corrections. Precise calculations of some relaxation rates and crude calculations of electron transport coefficients have been made. As one of major applications of the modified Fokker-Planck equation, the stopping powers and {rho}R have been calculated for charged fusion products ({alpha}`s, {sup 3}H, {sup 3}He) and hot electrons interacting with plasmas relevant to inertial confinement fusion. In the second major topic of this thesis, advances made in the area of laboratory x-ray sources are presented. First, and most importantly, through the use a Cockcroft-Walton linear accelerator, a charged particle induced x-ray emission (PIXE) source has been developed. Intense line x radiation (including K-, L-, M-, and N-lines) with wavelengths from 0.5 {angstrom} to 111 {angstrom} have been successfully produced. Second, a new high intensity electron-beam x-ray generator has also been developed, and it has been used with advantage in the soft x-ray region ( < 3 keV). Finally, a direct comparisons of both sources (PIXE and electron-beam x-ray sources) to a commercially available radioactive {alpha} fluorescent x-ray source has been made.