WorldWideScience

Sample records for fast x-ray emission

  1. Ultra fast atomic process in X-ray emission by inner-shell ionization

    Energy Technology Data Exchange (ETDEWEB)

    Moribayashi, Kengo; Sasaki, Akira [Japan Atomic Energy Research Inst., Neyagawa, Osaka (Japan). Kansai Research Establishment; Tajima, T

    1998-03-01

    An ultra-fast atomic process together with X-ray emission by inner-shell ionization using high intensity (10{sup 18} W/cm{sup 2}) short pulse (20fs) X-ray is studied. A new class of experiment is proposed and a useful pumping source is suggested. In this method, it is found that the gain value of X-ray laser amounts to larger than 1000(1/cm) with use of the density of 10{sup 22}/cm{sup 3} of carbon atom. Electron impact ionization effect and initial density effect as well as intensity of pumping source effect are also discussed. (author)

  2. Measurements of fast electron beams and soft X-ray emission from plasma-focus experiments

    Directory of Open Access Journals (Sweden)

    Surała Władysław

    2016-06-01

    Full Text Available The paper reports results of the recent experimental studies of pulsed electron beams and soft X-rays in plasma-focus (PF experiments carried out within a modified PF-360U facility at the NCBJ, Poland. Particular attention was focused on time-resolved measurements of the fast electron beams by means of two different magnetic analyzers, which could record electrons of energy ranging from about 41 keV to about 715 keV in several (6 or 8 measuring channels. For discharges performed with the pure deuterium filling, many strong electron signals were recorded in all the measuring channels. Those signals were well correlated with the first hard X-ray pulse detected by an external scintillation neutron-counter. In some of the analyzer channels, electron spikes (lasting about dozens of nanoseconds and appearing in different instants after the current peculiarity (so-called current dip were also recorded. For several discharges, fast ion beams, which were emitted along the z-axis and recorded with nuclear track detectors, were also investigated. Those measurements confirmed a multibeam character of the ion emission. The time-integrated soft X-ray images, which were taken side-on by means of a pinhole camera and sensitive X-ray films, showed the appearance of some filamentary structures and so-called hot spots. The application of small amounts of admixtures of different heavy noble gases, i.e. of argon (4.8% volumetric, krypton (1.6% volumetric, or xenon (0.8% volumetric, decreased intensity of the recorded electron beams, but increased intensity of the soft X-ray emission and showed more distinct and numerous hot spots. The recorded electron spikes have been explained as signals produced by quasi-mono-energetic microbeams emitted from tiny sources (probably plasma diodes, which can be formed near the observed hot spots.

  3. Fast simulation of Proton Induced X-Ray Emission Tomography using CUDA

    Energy Technology Data Exchange (ETDEWEB)

    Beasley, D.G., E-mail: dgbeasley@itn.pt; Marques, A.C.; Alves, L.C.; Silva, R.C. da

    2013-07-01

    A new 3D Proton Induced X-Ray Emission Tomography (PIXE-T) and Scanning Transmission Ion Microscopy Tomography (STIM-T) simulation software has been developed in Java and uses NVIDIA™ Common Unified Device Architecture (CUDA) to calculate the X-ray attenuation for large detector areas. A challenge with PIXE-T is to get sufficient counts while retaining a small beam spot size. Therefore a high geometric efficiency is required. However, as the detector solid angle increases the calculations required for accurate reconstruction of the data increase substantially. To overcome this limitation, the CUDA parallel computing platform was used which enables general purpose programming of NVIDIA graphics processing units (GPUs) to perform computations traditionally handled by the central processing unit (CPU). For simulation performance evaluation, the results of a CPU- and a CUDA-based simulation of a phantom are presented. Furthermore, a comparison with the simulation code in the PIXE-Tomography reconstruction software DISRA (A. Sakellariou, D.N. Jamieson, G.J.F. Legge, 2001) is also shown. Compared to a CPU implementation, the CUDA based simulation is approximately 30× faster.

  4. Fast simulation of Proton Induced X-Ray Emission Tomography using CUDA

    International Nuclear Information System (INIS)

    Beasley, D.G.; Marques, A.C.; Alves, L.C.; Silva, R.C. da

    2013-01-01

    A new 3D Proton Induced X-Ray Emission Tomography (PIXE-T) and Scanning Transmission Ion Microscopy Tomography (STIM-T) simulation software has been developed in Java and uses NVIDIA™ Common Unified Device Architecture (CUDA) to calculate the X-ray attenuation for large detector areas. A challenge with PIXE-T is to get sufficient counts while retaining a small beam spot size. Therefore a high geometric efficiency is required. However, as the detector solid angle increases the calculations required for accurate reconstruction of the data increase substantially. To overcome this limitation, the CUDA parallel computing platform was used which enables general purpose programming of NVIDIA graphics processing units (GPUs) to perform computations traditionally handled by the central processing unit (CPU). For simulation performance evaluation, the results of a CPU- and a CUDA-based simulation of a phantom are presented. Furthermore, a comparison with the simulation code in the PIXE-Tomography reconstruction software DISRA (A. Sakellariou, D.N. Jamieson, G.J.F. Legge, 2001) is also shown. Compared to a CPU implementation, the CUDA based simulation is approximately 30× faster

  5. X-ray emission spectroscopy. X-ray fluorescence

    International Nuclear Information System (INIS)

    Despujols, J.

    1992-01-01

    Principles of X-ray emission spectrometry are first recalled, then wave-length dispersive and energy dispersive X-ray fluorescence spectrometer are described. They are essentially designed for qualitative and quantitative analysis of elements (Z>10). Sample preparation, calibration, corrections, interferences, accuracy are reviewed. Examples of use in different industries are given. (71 refs.)

  6. X-ray Emission from Solar Flares

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... Solar flares; X-ray detectors; X-ray line emission and continuum; break energy; microflares. Abstract. Solar X-ray Spectrometer (SOXS), the first space-borne solar astronomy experiment of India was designed to improve our current understanding of X-ray emission from the Sun in general and solar flares in ...

  7. Fast plasma discharge capillary design as a high power throughput soft x-ray emission source.

    Science.gov (United States)

    Wyndham, E S; Favre, M; Valdivia, M P; Valenzuela, J C; Chuaqui, H; Bhuyan, H

    2010-09-01

    We present the experimental details and results from a low energy but high repetition rate compact plasma capillary source for extreme ultraviolet and soft x-ray research and applications. Two lengths of capillary are mounted in two versions of a closely related design. The discharge operates in 1.6 and 3.2 mm inner diameter alumina capillaries of lengths 21 and 36 mm. The use of water both as dielectric and as coolant simplifies the compact low inductance design with nanosecond discharge periods. The stored electrical energy of the discharge is approximately 0.5 J and is provided by directly charging the capacitor plates from an inexpensive insulated-gate bipolar transistor in 1 μs or less. We present characteristic argon spectra from plasma between 30 and 300 Å as well as temporally resolved x-ray energy fluence in discrete bands on axis. The spectra also allow the level of ablated wall material to be gauged and associated with useful capillary lifetime according to the chosen configuration and energy storage. The connection between the electron beams associated with the transient hollow cathode mechanism, soft x-ray output, capillary geometry, and capillary lifetime is reported. The role of these e-beams and the plasma as measured on-axis is discussed. The relation of the electron temperature and the ionization stages observed is discussed in the context of some model results of ionization in a non-Maxwellian plasma.

  8. Soft X-ray emission of a fast-capillary-discharge device

    Czech Academy of Sciences Publication Activity Database

    Schmidt, Jiří; Koláček, Karel; Štraus, Jaroslav; Prukner, Václav; Frolov, Oleksandr; Boháček, Vladislav

    2005-01-01

    Roč. 13, č. 2 (2005), s. 105-109 ISSN 1051-9998. [International Conference on High- Power Particle Beams, BEAMS /15th./. St. Petersburg, 18.7.2004-23.7.2004] R&D Projects: GA AV ČR(CZ) KSK2043105; GA ČR(CZ) GA202/03/0711 Institutional research plan: CEZ:AV0Z20430508 Keywords : pre-pulse plasma * capillary discharge * soft X-ray laser Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.271, year: 2005

  9. Ultra fast x-ray streak camera

    International Nuclear Information System (INIS)

    Coleman, L.W.; McConaghy, C.F.

    1975-01-01

    A unique ultrafast x-ray sensitive streak camera, with a time resolution of 50psec, has been built and operated. A 100A thick gold photocathode on a beryllium vacuum window is used in a modified commerical image converter tube. The X-ray streak camera has been used in experiments to observe time resolved emission from laser-produced plasmas. (author)

  10. High-Resolution X-ray Emission and X-ray Absorption Spectroscopy

    NARCIS (Netherlands)

    Groot, F.M.F. de

    2000-01-01

    In this review, high-resolution X-ray emission and X-ray absorption spectroscopy will be discussed. The focus is on the 3d transition-metal systems. To understand high-resolution X-ray emission and reso-nant X-ray emission, it is first necessary to spend some time discussing the X-ray absorption

  11. Proton induced X-ray emission analysis

    International Nuclear Information System (INIS)

    Khan, Rashiduzzman

    1976-09-01

    The developments in proton induced X-ray emission analysis are reviewed. Techniques for analyzing thick and thin samples of different origin are described. Discussions on the application of proton induced X-ray emission analysis in different fields, comparison of the sensitivity of this method with other analytical techniques, its limitations and possible improvements are presented

  12. Fast and Furious: Shock heated gas as the origin of spatially resolved hard X-ray emission in the central 5 kpc of the galaxy merger NGC 6240

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Junfeng; Nardini, Emanuele; Fabbiano, Giuseppina; Karovska, Margarita; Elvis, Martin; Risaliti, Guido; Zezas, Andreas [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Pellegrini, Silvia [Dipartimento di Astronomia, Universitá di Bologna, Via Ranzani 1, I-40127 Bologna (Italy); Max, Claire [Center for Adaptive Optics, University of California, 1156 High Street, Santa Cruz, CA 95064 (United States); U, Vivian, E-mail: jfwang@northwestern.edu [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)

    2014-01-20

    We have obtained a deep, subarcsecond resolution X-ray image of the nuclear region of the luminous galaxy merger NGC 6240 with Chandra, which resolves the X-ray emission from the pair of active nuclei and the diffuse hot gas in great detail. We detect extended hard X-ray emission from kT ∼ 6 keV (∼70 MK) hot gas over a spatial scale of 5 kpc, indicating the presence of fast shocks with a velocity of ∼2200 km s{sup –1}. For the first time, we obtain the spatial distribution of this highly ionized gas emitting Fe XXV, which shows a remarkable correspondence to the large-scale morphology of H{sub 2}(1-0) S(1) line emission and Hα filaments. Propagation of fast shocks originating in the starburst-driven wind into the ambient dense gas can account for this morphological correspondence. With an observed L {sub 0.5-8} {sub keV} = 5.3 × 10{sup 41} erg s{sup –1}, the diffuse hard X-ray emission is ∼100 times more luminous than that observed in the classic starburst galaxy M82. Assuming a filling factor of 1% for the 70 MK temperature gas, we estimate its total mass (M {sub hot} = 1.8 × 10{sup 8} M {sub ☉}) and thermal energy (E {sub th} = 6.5 × 10{sup 57} erg). The total iron mass in the highly ionized plasma is M {sub Fe} = 4.6 × 10{sup 5} M {sub ☉}. Both the energetics and the iron mass in the hot gas are consistent with the expected injection from the supernovae explosion during the starburst that is commensurate with its high star formation rate. No evidence for fluorescent Fe I emission is found in the CO filament connecting the two nuclei.

  13. Fast and Furious: Shock Heated Gas as the Origin of Spatially Resolved Hard X-Ray Emission in the Central 5 kpc of the Galaxy Merger NGC 6240

    Science.gov (United States)

    Wang, Junfeng; Nardini, Emanuele; Fabbiano, Giuseppina; Karovska, Margarita; Elvis, Martin; Pellegrini, Silvia; Max, Claire; Risaliti, Guido; U, Vivian; Zezas, Andreas

    2014-01-01

    We have obtained a deep, subarcsecond resolution X-ray image of the nuclear region of the luminous galaxy merger NGC 6240 with Chandra, which resolves the X-ray emission from the pair of active nuclei and the diffuse hot gas in great detail. We detect extended hard X-ray emission from kT ~ 6 keV (~70 MK) hot gas over a spatial scale of 5 kpc, indicating the presence of fast shocks with a velocity of ~2200 km s-1. For the first time, we obtain the spatial distribution of this highly ionized gas emitting Fe XXV, which shows a remarkable correspondence to the large-scale morphology of H2(1-0) S(1) line emission and Hα filaments. Propagation of fast shocks originating in the starburst-driven wind into the ambient dense gas can account for this morphological correspondence. With an observed L 0.5-8 keV = 5.3 × 1041 erg s-1, the diffuse hard X-ray emission is ~100 times more luminous than that observed in the classic starburst galaxy M82. Assuming a filling factor of 1% for the 70 MK temperature gas, we estimate its total mass (M hot = 1.8 × 108 M ⊙) and thermal energy (E th = 6.5 × 1057 erg). The total iron mass in the highly ionized plasma is M Fe = 4.6 × 105 M ⊙. Both the energetics and the iron mass in the hot gas are consistent with the expected injection from the supernovae explosion during the starburst that is commensurate with its high star formation rate. No evidence for fluorescent Fe I emission is found in the CO filament connecting the two nuclei.

  14. Fast and Furious: Shock heated gas as the origin of spatially resolved hard X-ray emission in the central 5 kpc of the galaxy merger NGC 6240

    International Nuclear Information System (INIS)

    Wang, Junfeng; Nardini, Emanuele; Fabbiano, Giuseppina; Karovska, Margarita; Elvis, Martin; Risaliti, Guido; Zezas, Andreas; Pellegrini, Silvia; Max, Claire; U, Vivian

    2014-01-01

    We have obtained a deep, subarcsecond resolution X-ray image of the nuclear region of the luminous galaxy merger NGC 6240 with Chandra, which resolves the X-ray emission from the pair of active nuclei and the diffuse hot gas in great detail. We detect extended hard X-ray emission from kT ∼ 6 keV (∼70 MK) hot gas over a spatial scale of 5 kpc, indicating the presence of fast shocks with a velocity of ∼2200 km s –1 . For the first time, we obtain the spatial distribution of this highly ionized gas emitting Fe XXV, which shows a remarkable correspondence to the large-scale morphology of H 2 (1-0) S(1) line emission and Hα filaments. Propagation of fast shocks originating in the starburst-driven wind into the ambient dense gas can account for this morphological correspondence. With an observed L 0.5-8 keV = 5.3 × 10 41 erg s –1 , the diffuse hard X-ray emission is ∼100 times more luminous than that observed in the classic starburst galaxy M82. Assuming a filling factor of 1% for the 70 MK temperature gas, we estimate its total mass (M hot = 1.8 × 10 8 M ☉ ) and thermal energy (E th = 6.5 × 10 57 erg). The total iron mass in the highly ionized plasma is M Fe = 4.6 × 10 5 M ☉ . Both the energetics and the iron mass in the hot gas are consistent with the expected injection from the supernovae explosion during the starburst that is commensurate with its high star formation rate. No evidence for fluorescent Fe I emission is found in the CO filament connecting the two nuclei.

  15. Metrology and X-rays emissions

    International Nuclear Information System (INIS)

    Chancel, C.; Schirmann, D.

    1993-01-01

    This scientific journal explains different technologies used to study X-rays emissions hot dense plasmas created by laser at the Dam center of Limeil-Valenton (CEL-V) or created by nuclear fire in the Pacific

  16. X-ray emission from comets

    International Nuclear Information System (INIS)

    Dennerl, Konrad

    1999-01-01

    When comet Hyakutake (C/1996 B2) encountered Earth in March 1996 at a minimum distance of only 15 million kilometers (40 times the distance of the moon), x-ray and extreme ultraviolet emission was discovered for the first time from a comet. The observations were performed with the astronomy satellites ROSAT and EUVE. A systematic search for x-rays from comets in archival data, obtained during the ROSAT all-sky survey in 1990/91, resulted in the discovery of x-ray emission from four additional comets. They were detected at seven occasions in total, when they were optically 300 to 30 000 times fainter than Hyakutake. These findings indicated that comets represent a new class of celestial x-ray sources. Subsequent detections of x-ray emission from additional comets with the satellites ROSAT, EUVE, and BeppoSAX confirmed this conclusion. The x-ray observations have obviously revealed the presence of a process in comets which had escaped attention until recently. This process is most likely charge exchange between highly charged heavy ions in the solar wind and cometary neutrals. The solar wind, a stream of particles continuously emitted from the sun with ≅ 400 km s -1 , consists predominantly of protons, electrons, and alpha particles, but contains also a small fraction (≅0.1%) of highly charged heavier ions, such as C 6+ ,O 6+ ,Ne 8+ ,Si 9+ ,Fe 11+ . When these ions capture electrons from the cometary gas, they attain highly excited states and radiate a large fraction of their excitation energy in the extreme ultraviolet and x-ray part of the spectrum. Charge exchange reproduces the intensity, the morphology and the spectrum of the observed x-ray emission from comets very well

  17. Ultrafast secondary emission x-ray imaging detectors

    International Nuclear Information System (INIS)

    Akkerman, A.; Gibrekhterman, A.; Majewski, S.

    1991-07-01

    Fast high accuracy, x-ray imaging at high photon flux can be achieved when coupling thin solid convertors to gaseous electron multipliers, operating at low gas pressures. Secondary electron emitted from the convertor foil are multiplied in several successive amplification elements. The obvious advantage of solid x-ray detectors, as compared to gaseous conversion, are the production of parallax-free images and the fast (subnanoseconds) response. These x-ray detectors have many potential applications in basic and applied research. Of particular interest is the possibility of an efficient and ultrafast high resolution imaging of transition radiation,with a reduced dE/dx background. We present experimental results on the operation of the secondary emission x-ray (SEX) detectors, their detection efficiency, localization and time resolution. The experimental work is accompanied by mathematical modelling and computer simulation of transition radiation detectors based on CsI transition radiation convertors. (author)

  18. The Swift Supergiant Fast X-ray Transient Project

    Science.gov (United States)

    Romano, P.; Barthelmy, S.; Bozzo, E.; Burrows, D.; Ducci, L.; Esposito, P.; Evans, P.; Kennea, J.; Krimm, H.; Vercellone, S.

    2017-10-01

    We present the Swift Supergiant Fast X-ray Transients project, a systematic study of SFXTs and classical supergiant X-ray binaries (SGXBs) through efficient long-term monitoring of 17 sources including SFXTs and classical SGXBs across more than 4 orders of magnitude in X-ray luminosity on timescales from hundred seconds to years. We derived dynamic ranges, duty cycles, and luminosity distributions to highlight systematic differences that help discriminate between different theoretical models proposed to explain the differences between the wind accretion processes in SFXTs and classical SGXBs. Our follow-ups of the SFXT outbursts provide a steady advancement in the comprehension of the mechanisms triggering the high X-ray level emission of these sources. In particular, the observations of the outburst of the SFXT prototype IGR J17544-2619, when the source reached a peak X-ray luminosity of 3×10^{38} erg s^{-1}, challenged for the first time the maximum theoretical luminosity achievable by a wind-fed neutron star high mass X-ray binary. We propose that this giant outburst was due to the formation of a transient accretion disc around the compact object. We also created a catalogue of over 1000 BAT flares which we use to predict the observability and perspectives with future missions.

  19. Characterization of X-ray emission from laser generated plasma

    Science.gov (United States)

    Cannavò, Antonino; Torrisi, Lorenzo; Ceccio, Giovanni; Cutroneo, Mariapompea; Calcagno, Lucia; Sciuto, Antonella; Mazzillo, Massimo

    2018-01-01

    X-ray emission from laser generated plasma was studied at low (1010 W/cm2) and high (1018 W/cm2) intensity using ns and fs laser, respectively. Plasma characteristics were controlled trough the laser parameters, the irradiation conditions and the target properties. The X-ray spectra were acquired using fast detection technique based on SiC diodes with different active regions. The X-ray yield increases with the atomic number of the target, both at low and high intensity, and a similar empirical law has been obtained. The X-ray emission mechanisms from plasma are correlated to the plasma temperature and density and to the Coulomb charge particle acceleration, due to the charge separation effects produced in the non-equilibrium plasma. Functional dependences, theoretical approaches and interpretation of possible mechanism will be presented and discussed.

  20. Characterization of X-ray emission from laser generated plasma

    Directory of Open Access Journals (Sweden)

    Cannavò Antonino

    2018-01-01

    Full Text Available X-ray emission from laser generated plasma was studied at low (1010 W/cm2 and high (1018 W/cm2 intensity using ns and fs laser, respectively. Plasma characteristics were controlled trough the laser parameters, the irradiation conditions and the target properties. The X-ray spectra were acquired using fast detection technique based on SiC diodes with different active regions. The X-ray yield increases with the atomic number of the target, both at low and high intensity, and a similar empirical law has been obtained. The X-ray emission mechanisms from plasma are correlated to the plasma temperature and density and to the Coulomb charge particle acceleration, due to the charge separation effects produced in the non-equilibrium plasma. Functional dependences, theoretical approaches and interpretation of possible mechanism will be presented and discussed.

  1. Ion induced x-ray emission

    International Nuclear Information System (INIS)

    Cohen, D.D.; Clayton, E.

    1989-01-01

    This paper discusses particle induced x-ray emission (PIXE). Its use as a tool for multi-element non-destructive trace element analysis of small samples is addressed. Concepts and details needed for the construction of a PIXE system are offered

  2. Fast calculator for X-ray emission due to Radiative Recombination and Radiative Electron Capture in relativistic heavy-ion atom collisions

    Science.gov (United States)

    Herdrich, M. O.; Weber, G.; Gumberidze, A.; Wu, Z. W.; Stöhlker, Th.

    2017-10-01

    In experiments with highly charged, fast heavy ions the Radiative Recombination (RR) and Radiative Electron Capture (REC) processes have significant cross sections in an energy range of up to a few GeV / u . They are some of the most important charge changing processes in collisions of heavy ions with atoms and electrons, leading to the emission of a photon along with the formation of the ground and excited atomic states. Hence, for the understanding and planning of experiments, in particular for X-ray spectroscopy studies, at accelerator ring facilities, such as FAIR, it is crucial to have a good knowledge of these cross sections and the associated radiation characteristics. In the frame of this work a fast calculator, named RECAL, for the RR and REC process is presented and its capabilities are demonstrated with the analysis of a recently conducted experiment at the Experimental Storage Ring (ESR) at the GSI Helmholtz Center for Heavy Ion Research in Darmstadt, Germany. A method is presented to determine unknown X-ray emission cross sections via normalization of the recorded spectra to REC cross sections calculated by RECAL.

  3. X-ray emission from hot plasma

    International Nuclear Information System (INIS)

    Hayakawa, Satio; Kato, Takako.

    1979-01-01

    X-ray emission from hot plasmas is discussed with a critical review of different theories. The results given in the present paper are complementary to those given by Kato in the sense that the present paper is introductory to the paper by Kato. The contents of the present paper are; 1. Introduction 2. Ionization and Recombination Rate Coefficients 3. Relative Abundances of Ions 4. Intensity and Spectra of Radiation 5. Comparison with Earlier Results 6. Emission and Absorption Lines (author)

  4. Particle induced X-ray emission

    International Nuclear Information System (INIS)

    Cohen, D.D.

    1991-08-01

    The accelerator based ion beam technique of Particle Induced X-ray Emission (PIXE) is discussed in some detail. This report pulls together all major reviews and references over the last ten years and reports on PIXE in vacuum and using external beams. The advantages, limitations, costs and types of studies that may be undertaken using an accelerator based ion beam technique such as PIXE, are also discussed. 25 refs., 7 tabs., 40 figs

  5. X-Ray Emission Properties of Supernova Remnants

    NARCIS (Netherlands)

    Vink, J.; Alsabti, A.W.; Murdin, P.

    2016-01-01

    X-ray emission from supernova remnants can be broadly divided into thermal X-ray emission from the shock-heated plasmas and in nonthermal (synchrotron) emission caused by very high-energy (10–100 TeV) electrons moving in the magnetic fields of the hot plasmas. The thermal X-ray emission of young

  6. X-Ray-Driven Gamma Emission

    International Nuclear Information System (INIS)

    Carroll, J. J.; Karamian, S. A.; Rivlin, L. A.; Zadernovsky, A. A.

    2001-01-01

    X-ray-driven gamma emission describes processes that may release nuclear energy in a 'clean' way, as bursts of incoherent or coherent gamma rays without the production of radioactive by-products. Over the past decade, studies in this area, as a part of the larger field of quantum nucleonics, have gained tremendous momentum. Since 1987 it has been established that photons could trigger gamma emission from a long-lived metastable nuclear excited state of one nuclide and it appears likely that triggering in other isotopes will be demonstrated conclusively in the near future. With these experimental results have come new proposals for the creation of collective and avalanche-like incoherent gamma-ray bursts and even for the ultimate light source, a gamma-ray laser. Obviously, many applications would benefit from controlled bursts of gamma radiation, whether coherent or not. This paper reviews the experimental results and concepts for the production of gamma rays, driven by externally produced X-rays

  7. Observing Solvation Dynamics with Simultaneous Femtosecond X-ray Emission Spectroscopy and X-ray Scattering

    DEFF Research Database (Denmark)

    Haldrup, Kristoffer; Gawelda, Wojciech; Abela, Rafael

    2016-01-01

    and structural changes, and local solvent structural changes are desired. We have studied the intra- and intermolecular dynamics of a model chromophore, aqueous [Fe(bpy)3]2+, with complementary X-ray tools in a single experiment exploiting intense XFEL radiation as a probe. We monitored the ultrafast structural...... rearrangement of the solute with X-ray emission spectroscopy, thus establishing time zero for the ensuing X-ray diffuse scattering analysis. The simultaneously recorded X-ray diffuse scattering atterns reveal slower subpicosecond dynamics triggered by the intramolecular structural dynamics of the photoexcited...

  8. Theory of X-ray absorption and emission spectra

    International Nuclear Information System (INIS)

    Mukoyama, Takeshi

    2004-01-01

    Theoretical studies on X-ray absorption and emission spectroscopy are discussed. Simple expressions for X-ray emission rate and X-ray absorption cross section are presented in the dipole approximation. Various atomic models to obtain realistic wave functions and theoretical calculations for X-ray absorption cross sections and X-ray emission rates are described. In the case of molecules and solids, molecular orbital methods for electronic structures and molecular wave functions are discussed. The emphasis is on the procedures to obtain the excited-state and continuum wave functions for molecules and to calculate the multi-center dipole matrix elements. The examples of the calculated X-ray absorption and emission spectra are shown and compared with the experimental results

  9. Repeated pulsed x-ray emission equipment

    International Nuclear Information System (INIS)

    Terauchi, Hikaru; Iida, Satoshi

    1982-01-01

    X-ray diffraction technique has been applied to determine the spatial positions of atoms which compose a material, and it is needless to say that the technique is a fundamental means regardless of the fields of research. However, the application of X-ray diffraction to the research on physical properties has been so far limited to know the spatial positions of atoms or molecules under thermal equilibrium condition. The addition of time element to the conventional technique, that is, the analysis of material structure including the time-varying processes under non-equilibrium conditions, is considered to approach the elucidation of the essence of materials. The authors call this dynamic structural analysis. The authors have planned to analyze X-ray diffraction intensity which has the resolution of about 10 -8 s in the real time which is conjugate with energy. However, present pulsed X-ray sources are not suitable for diffraction experiment because the pulse width is too long or X-ray wavelength is too short. Accordingly, the authors have made for trial a pulsed X-ray source for diffraction experiment. Its specifications are: diode voltage (X-ray tube voltage) from 200 to 300 kV, diode current from 2 to 5 kA, pulse width of about 30ns, maximum repetition frequency 10 pps, and X-ray focus size of 2 mm diameter. One of the features of this source is the repeated generation of pulsed X-ray. This is the first trial in the world, and is indispensable to the dynamic structural analysis described above. The quality of the emitted X-ray is also written. (Wakatsuki, Y.)

  10. Characterization of nuclear physics targets using Rutherford backscattering and particle induced X-ray emission

    International Nuclear Information System (INIS)

    Rubehn, T.; Wozniak, G.J.; Phair, L.; Moretto, L.G.; Yu, K.M.

    1997-01-01

    Rutherford backscattering and particle induced X-ray emission have been utilized to precisely characterize targets used in nuclear fission experiments. The method allows for a fast and non-destructive determination of target thickness, homogeneity and element composition. (orig.)

  11. Chemical effects in x-ray emission spectra

    International Nuclear Information System (INIS)

    Fernandes, N.G.

    1982-01-01

    The chemical bond influence in X-ray emission spectra of hafnium, iodine, iron, sulphur, aluminium and magnesium is detected. The position of one X-ray emission line is determined by three methods: parabolic profile; Gaussian distribution and extra-heavy maximum. (author)

  12. X-Ray Emission from Compact Sources

    Energy Technology Data Exchange (ETDEWEB)

    Cominsky, L

    2004-03-23

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

  13. Characterizing X-Ray and Radio Emission in the Black Hole X-Ray Binary V404 Cygni During Quiescence

    Science.gov (United States)

    Rana, Vikram; Loh, Alan; Corbel, Stephane; Tomsick, John A.; Chakrabarty, Deepto; Walton, Dominic J.; Barret, Didier; Boggs, Steven E.; Christensen, Finn E.; Craig, William; hide

    2016-01-01

    We present results from multi-wavelength simultaneous X-ray and radio observations of the black hole X-ray binary V404 Cyg in quiescence. Our coverage with NuSTAR provides the very first opportunity to study the X-ray spectrum of V404 Cyg at energies above 10 keV. The unabsorbed broadband (0.3-30 keV) quiescent luminosity of the source is 8.9 x 10(exp 32) erg per sec for a distance of 2.4 kpc. The source shows clear variability on short timescales (an hour to a couple of hours) in the radio, soft X-ray, and hard X-ray bands in the form of multiple flares. The broadband X-ray spectra obtained from XMM-Newton and NuSTAR can be characterized with a power-law model having a photon index of gamma = 2.12 +/- 0.07 (90% confidence errors); however, residuals at high energies indicate spectral curvature significant at a 3 sigma confidence level with the e-folding energy of the cutoff as 20(sub -7)(sup +20) keV. Such curvature can be explained using synchrotron emission from the base of a jet outflow. Radio observations using the VLA reveal that the spectral index evolves on very fast timescales (as short as 10 minutes), switching between optically thick and thin synchrotron emission, possibly due to instabilities in the compact jet or stochastic instabilities in the accretion rate. We explore different scenarios to explain this very fast variability.

  14. Radio and X-ray emission from supernova remnants

    International Nuclear Information System (INIS)

    Asvarova, A.I.; Novruzova, H.I.; Ahmedova, S.I.

    2010-01-01

    In this paper it was studied the statistical correlation between radio and X-ray emissions from shell-type supernova remnants (SNR). The primary aim of this study is to test the model of radio emission of shell-type SNRs presented by one of the authors. Based on this model of radio emission, by using the Monte Carlo techniques we have simulated statistical relations radio - X-ray luminosities (not surface brightnesses) which then were compared with the observations. X-ray emission is assumed to be thermal. To have a uniform statistical material it was used observational data on the SNRs in Magellanic Clouds

  15. X-ray and extreme ultraviolet emission from comets

    Science.gov (United States)

    Lisse, C. M.; Cravens, T. E.; Dennerl, K.

    The discovery of high energy X-ray emission in 1996 from C/1996 B2 (Hyakutake) has created a surprising new class of X-ray emitting objects. The original discovery (Lisse et al., 1996) and subsequent detection of X-rays from 17 other comets (Table 1) have shown that the very soft (E < 1 keV) emission is due to an interaction between the solar wind and the comet's atmosphere, and that X-ray emission is a fundamental property of comets. Theoretical and observational work has demonstrated that charge exchange collisions of highly charged solar wind ions with cometary neutral species is the best explanation for the emission. Now a rapidly changing and expanding field, the study of cometary X-ray emission appears to be able to lead us to a better understanding of a number of physical phenomena: the nature of the cometary coma, other sources of X-ray emission in the solar system, the structure of the solar wind in the heliosphere, and the source of the local soft X-ray background.

  16. X-ray emission from Centaurus A

    International Nuclear Information System (INIS)

    Terrell, J.

    1984-01-01

    The X-ray strength of Cen A (NGC 5128) was monitored for 10 years by Vela 5B, beginning in 1979. The 1973 to 1975 period of exceptional activity and strength was especially well covered, and was characterized by numerous rapid changes in intensity, in agreement with other data, indicating that the nucleus of Cen A is small but massive. 16 references, 3 figures

  17. X-ray Emission from the Guitar Nebula

    OpenAIRE

    Romani, Roger W.; Cordes, James M.; Yadigaroglu, I. -A.

    1997-01-01

    We have detected weak soft X-ray emission from the Pulsar Wind Nebula trailing the high velocity star PSR 2224+65 (the `Guitar Nebula'). This X-ray flux gives evidence of \\gamma~10^7 eV particles in the pulsar wind and constrains the properties of the post-shock flow. The X-ray emission is most easily understood if the shocked pulsar wind is partly confined in the nebula and if magnetic fields in this zone can grow to near equipartition values.

  18. X-Ray Emission from the Guitar Nebula

    Science.gov (United States)

    Romani, Roger W.; Cordes, James M.; Yadigaroglu, I.-A.

    1997-01-01

    We have detected weak soft X-ray emission from the pulsar wind nebula trailing the high-velocity star PSR 2224+65 (the "Guitar Nebula"). This X-ray flux gives evidence of gamma approximately 10(exp 7) eV particles in the pulsar wind and constrains the properties of the postshock flow. The X-ray emission is most easily understood if the shocked pulsar wind is partly confined in the nebula and if magnetic fields in this zone can grow to near-equipartition values.

  19. Stimulated X-Ray Emission Spectroscopy in Transition Metal Complexes

    Science.gov (United States)

    Kroll, Thomas; Weninger, Clemens; Alonso-Mori, Roberto; Sokaras, Dimosthenis; Zhu, Diling; Mercadier, Laurent; Majety, Vinay P.; Marinelli, Agostino; Lutman, Alberto; Guetg, Marc W.; Decker, Franz-Josef; Boutet, Sébastien; Aquila, Andy; Koglin, Jason; Koralek, Jake; DePonte, Daniel P.; Kern, Jan; Fuller, Franklin D.; Pastor, Ernest; Fransson, Thomas; Zhang, Yu; Yano, Junko; Yachandra, Vittal K.; Rohringer, Nina; Bergmann, Uwe

    2018-03-01

    We report the observation and analysis of the gain curve of amplified K α x-ray emission from solutions of Mn(II) and Mn(VII) complexes using an x-ray free electron laser to create the 1 s core-hole population inversion. We find spectra at amplification levels extending over 4 orders of magnitude until saturation. We observe bandwidths below the Mn 1 s core-hole lifetime broadening in the onset of the stimulated emission. In the exponential amplification regime the resolution corrected spectral width of ˜1.7 eV FWHM is constant over 3 orders of magnitude, pointing to the buildup of transform limited pulses of ˜1 fs duration. Driving the amplification into saturation leads to broadening and a shift of the line. Importantly, the chemical sensitivity of the stimulated x-ray emission to the Mn oxidation state is preserved at power densities of ˜1020 W /cm2 for the incoming x-ray pulses. Differences in signal sensitivity and spectral information compared to conventional (spontaneous) x-ray emission spectroscopy are discussed. Our findings build a baseline for nonlinear x-ray spectroscopy for a wide range of transition metal complexes in inorganic chemistry, catalysis, and materials science.

  20. Circumstellar X-ray Emission from SN1978K

    Science.gov (United States)

    Schlegel, Eric M.; Colbert, E.; Petre, R.

    1995-02-01

    We present the X-ray light curve in the 0.2 2.4 keV band based on fiveROSAT observations of SN1978K in NGC 1313. The X-ray emission is believed to arise from the interaction of the reverse shock and the expanding debris from the supernova. The reverse shock becomes established after the outgoing shock runs into circumstellar matter.

  1. Is X-ray emissivity constant on magnetic flux surfaces?

    International Nuclear Information System (INIS)

    Granetz, R.S.; Borras, M.C.

    1997-01-01

    Knowledge of the elongations and shifts of internal magnetic flux surfaces can be used to determine the q profile in elongated tokamak plasmas. X-ray tomography is thought to be a reasonable technique for independently measuring internal flux surface shapes, because it is widely believed that X-ray emissivity should be constant on a magnetic flux surface. In the Alcator C-Mod tokamak, the X-ray tomography diagnostic system consists of four arrays of 38 chords each. A comparison of reconstructed X-ray contours with magnetic flux surfaces shows a small but consistent discrepancy in the radial profile of elongation. Numerous computational tests have been performed to verify these findings, including tests of the sensitivity to calibration and viewing geometry errors, the accuracy of the tomography reconstruction algorithms, and other subtler effects. We conclude that the discrepancy between the X-ray contours and the magnetic flux surfaces is real, leading to the conclusion that X-ray emissivity is not exactly constant on a flux surface. (orig.)

  2. Synchrotron-Radiation Induced X-Ray Emission (SRIXE)

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Keith W.

    1999-09-01

    Elemental analysis using emission of characteristic x rays is a well-established scientific method. The success of this analytical method is highly dependent on the properties of the source used to produce the x rays. X-ray tubes have long existed as a principal excitation source, but electron and proton beams have also been employed extensively. The development of the synchrotron radiation x-ray source that has taken place during the past 40 years has had a major impact on the general field of x-ray analysis. Even tier 40 years, science of x-ray analysis with synchrotron x-ray beams is by no means mature. Improvements being made to existing synchrotron facilities and the design and construction of new facilities promise to accelerate the development of the general scientific use of synchrotron x-ray sources for at least the next ten years. The effective use of the synchrotron source technology depends heavily on the use of high-performance computers for analysis and theoretical interpretation of the experimental data. Fortunately, computer technology has advanced at least as rapidly as the x-ray technology during the past 40 years and should continue to do so during the next decade. The combination of these technologies should bring about dramatic advances in many fields where synchrotron x-ray science is applied. It is interesting also to compare the growth and rate of acceptance of this particular research endeavor to the rates for other technological endeavors. Griibler [1997] cataloged the time required for introduction, diffusion,and acceptance of technological, economic, and social change and found mean values of 40 to 50 years. The introduction of the synchrotron source depends on both technical and non-technical factors, and the time scale at which this seems to be occurring is quite compatible with what is seen for other major innovations such as the railroad or the telegraph. It will be interesting to see how long the present rate of technological change

  3. Synchrotron-Radiation Induced X-Ray Emission (SRIXE)

    International Nuclear Information System (INIS)

    Jones, Keith W.

    1999-01-01

    Elemental analysis using emission of characteristic x rays is a well-established scientific method. The success of this analytical method is highly dependent on the properties of the source used to produce the x rays. X-ray tubes have long existed as a principal excitation source, but electron and proton beams have also been employed extensively. The development of the synchrotron radiation x-ray source that has taken place during the past 40 years has had a major impact on the general field of x-ray analysis. Even tier 40 years, science of x-ray analysis with synchrotron x-ray beams is by no means mature. Improvements being made to existing synchrotron facilities and the design and construction of new facilities promise to accelerate the development of the general scientific use of synchrotron x-ray sources for at least the next ten years. The effective use of the synchrotron source technology depends heavily on the use of high-performance computers for analysis and theoretical interpretation of the experimental data. Fortunately, computer technology has advanced at least as rapidly as the x-ray technology during the past 40 years and should continue to do so during the next decade. The combination of these technologies should bring about dramatic advances in many fields where synchrotron x-ray science is applied. It is interesting also to compare the growth and rate of acceptance of this particular research endeavor to the rates for other technological endeavors. Griibler [1997] cataloged the time required for introduction, diffusion,and acceptance of technological, economic, and social change and found mean values of 40 to 50 years. The introduction of the synchrotron source depends on both technical and non-technical factors, and the time scale at which this seems to be occurring is quite compatible with what is seen for other major innovations such as the railroad or the telegraph. It will be interesting to see how long the present rate of technological change

  4. Observations of EUV and X-ray Emission from Comets

    Science.gov (United States)

    Lisse, C.

    The unexpected discovery of x-ray emission from Comet Hyakutake in March 1996 (Lisse et al. 1996) produced a number of questions about the physical mechanism producing the radiation. The original detection and subsequent observations have shown that the very soft (best fit thermal bremsstrahlung model kT0.2 keV) emission is due to an interaction between the solar wind and the comet's atmosphere. Using the results from the more than 15 comets detected to date in x-rays, I report here on the latest results on cometary x-ray emission, including new results from Chandra, and show that charge exchange between highly ionized minor ions in the solar wind and neutral gases in the cometary coma is the most likely operative mechanism. I then use this result to study a number of problems of astrophysical interest: the nature of the cometary coma, other possible sources of x-ray emission in the solar system, the structure of the solar wind in the heliosphere, and the source of the local x-ray background.

  5. X-ray Emission Line Spectroscopy of Nearby Galaxies

    Science.gov (United States)

    Wang, Daniel

    What are the origins of the diffuse soft X-ray emission from non-AGN galaxies? Preliminary analysis of XMM-Newton RGS spectra shows that a substantial fraction of the emission cannot arise from optically-thin thermal plasma, as commonly assumed, and may originate in charge exchange at the interface with neutral gas. We request the support for a comprehensive observing, data analysis, and modeling program to spectroscopically determine the origins of the emission. First, we will use our scheduled XMM-Newton AO-10 368 ks observations of the nearest compact elliptical galaxy M32 to obtain the first spectroscopic calibration of the cumulative soft X-ray emission from the old stellar population and will develop a spectral model for the charge exchange, as well as analysis tools to measure the spatial and kinematic properties of the X-ray line- emitting plasma. Second, we will characterize the truly diffuse emission from the hot plasma and/or its interplay with the neutral gas in a sample of galactic spheroids and active star forming/starburst regions in nearby galaxies observed by XMM-Newton. In particular, we will map out the spatial distributions of key emission lines and measure (or tightly constrain) the kinematics of hot plasma outflows for a few X-ray-emitting regions with high-quality RGS data. For galaxies with insufficient counting statistics in individual emission lines, we will conduct a spectral stacking analysis to constrain the average properties of the X-ray-emitting plasma. We will use the results of these X-ray spectroscopic analyses, together with complementary X-ray CCD imaging/spectral data and observations in other wavelength bands, to test the models of the emission. In addition to the charge exchange, alternative scenarios such as resonance scattering and relic AGN photo-ionization will also be examined for suitable regions. These studies are important to the understanding of the relationship between the diffuse soft X-ray emission and various

  6. L X-ray emission induced by heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Pajek, M. [Institute of Physics, Jan Kochanowski University, 25-406 Kielce (Poland); Banaś, D., E-mail: d.banas@ujk.edu.pl [Institute of Physics, Jan Kochanowski University, 25-406 Kielce (Poland); Braziewicz, J.; Majewska, U.; Semaniak, J. [Institute of Physics, Jan Kochanowski University, 25-406 Kielce (Poland); Fijał-Kirejczyk, I. [The Institute of Atomic Energy, 05-400 Otwock-Świerk (Poland); Jaskóła, M.; Czarnacki, W.; Korman, A. [The National Centre for Nuclear Research, 05-400 Otwock-Świerk (Poland); Kretschmer, W. [Physikalisches Institut, Universität Erlangen-Nürnberg, D-91058 Erlangen (Germany); Mukoyama, T. [Institute for Nuclear Research, Hungarian Academy of Sciences (ATOMKI), H-4026 Debrecen (Hungary); Trautmann, D. [Institut für Physik, Universität Basel, Basel (Switzerland)

    2015-11-15

    Particle-induced X-ray emission (PIXE) technique is usually applied using typically 1 MeV to 3 MeV protons or helium ions, for which the ion-atom interaction is dominated by the single ionization process. For heavier ions the multiple ionization plays an increasingly important role and this process can influence substantially both the X-ray spectra and atomic decay rates. Additionally, the subshell coupling effects are important for the L- and M-shells ionized by heavy ions. Here we discuss the main features of the X-ray emission induced by heavy ions which are important for PIXE applications, namely, the effects of X-ray line shifts and broadening, vacancy rearrangement and change of the fluorescence and Coster–Kronig yields in multiple ionized atoms. These effects are illustrated here by the results of the measurements of L X-ray emission from heavy atoms bombarded by 6 MeV to 36 MeV Si ions, which were reported earlier. The strong L-subshell coupling effects are observed, in particular L{sub 2}-subshell, which can be accounted for within the coupling subshell model (CSM) developed within the semiclassical approximation. Finally, the prospects to use heavy ions in PIXE analysis are discussed.

  7. X-Ray and Near-Infrared Spectroscopy of Dim X-Ray Point Sources Constituting the Galactic Ridge X-Ray Emission

    Directory of Open Access Journals (Sweden)

    Kumiko Morihana

    2014-12-01

    Full Text Available We present the results of X-ray and Near-Infrared observations of the Galactic Ridge X-ray Emission (GRXE. We extracted 2,002 X-ray point sources in the Chandra Bulge Field (l =0°.113, b = 1°.424 down to ~10-14.8 ergscm-2s-1 in 2-8 keV band with the longest observation (900 ks of the GRXE. Based on X-ray brightness and hardness, we classied the X-ray point sources into three groups: A (hard, B (soft and broad spectrum, and C (soft and peaked spectrum. In order to know populations of the X-ray point sources, we carried out NIR imaging and spectroscopy observation. We identied 11% of X-ray point sources with NIR and extracted NIR spectra for some of them. Based on X-ray and NIR properties, we concluded that non-thermal sources in the group A are mostly active galactic nuclei and the thermal sources are mostly white dwarf binaries such as cataclysmic variables (CVs and Pre-CVs. We concluded that the group B and C sources are X-ray active stars in flare and quiescence, respectively.

  8. Resonant X-ray emission spectroscopy in Dy compounds

    International Nuclear Information System (INIS)

    Tanaka, Satoshi; Okada, Kozo; Kotani, Akio.

    1994-01-01

    The excitation spectrum of the L 3 -M 5 X-ray emission of Dy compounds in the pre-edge region of Dy L 3 X-ray absorption near edge structure (L 3 -XANES) is theoretically investigated based upon the coherent second order optical formula with multiplet coupling effects. The spectral broadening of the excitation spectrum is determined by the M 5 core hole lifetime, being free from the L 3 core hole lifetime. The fine pre-edge structure of the L 3 edge due to the 2p→4f quadrupole transition can be seen in the excitation spectrum, while this structure is invisible in the conventional XANES, in agreement with the recent experimental results. We clarify the conditions for the excitation spectrum to be regarded as the absorption spectrum with a smaller width. The resonant X-ray emission spectra for various incident photon energies around the L 3 edge are also calculated. (author)

  9. Fast X-ray imaging of cavitating flows

    Energy Technology Data Exchange (ETDEWEB)

    Khlifa, Ilyass; Fuzier, Sylvie; Roussette, Olivier [Arts et Metiers ParisTech, Lille (France); Vabre, Alexandre [CEA Saclay, Gif-sur-Yvette (France); Hocevar, Marko [Faculty of Mechanical Engineering, University of Ljubljana, Ljubljana (Slovenia); Fezzaa, Kamel [Argonne National Laboratory, Advanced Photon Source, Lemont, IL (United States); Coutier-Delgosha, Olivier [Virginia Tech, Kevin T. Crofton Department of Aerospace and Ocean Engineering, Blacksburg, VA (United States)

    2017-11-15

    A new method based on ultra-fast X-ray imaging was developed in this work for the investigation of the dynamics and the structures of complex two-phase flows. In this paper, cavitation was created inside a millimetric 2D Venturi-type test section, while seeding particles were injected into the flow. Thanks to the phase-contrast enhancement technique provided by the APS (Advanced Photon Source) synchrotron beam, high definition X-ray images of the complex cavitating flows were obtained. These images contain valuable information about both the liquid and the gaseous phases. By means of image processing, the two phases were separated, and velocity fields of each phase were, therefore, calculated using image cross-correlations. The local vapour volume fractions were also obtained, thanks to the local intensity levels within the recorded images. These simultaneous measurements, provided by this new technique, afford more insight into the structure and the dynamic of two-phase flows as well as the interactions between them, and hence enable to improve our understanding of their behaviour. In the case of cavitating flows inside a Venturi-type test section, the X-ray measurements demonstrate, for the first time, the presence of significant slip velocities between the phases within sheet cavities for both steady and unsteady flow configurations. (orig.)

  10. Observational Trends of Cometary X-ray Emission

    Science.gov (United States)

    Lisse, C. M.

    2001-05-01

    The unexpected discovery of x-ray emission from Comet Hyakutake in March 1996 (Lisse et al. 1996) has produced a number of questions about the physical mechanism producing the radiation. The original detection and subsequent observations (Dennerl et al. 1997, Mumma et al. 1997, Krasnopolsky et al. 1998, Owens et al. 1998, Lisse et al. 1999, Lisse et a. 2001, Dennerl et al. 2001) have shown that the very soft (best fit thermal bremsstrahlung model kT = 0.23 keV) emission is due to an interaction between the solar wind and the comet's atmosphere. Using the results from the more than 15 comets detected to date in x-rays, we report on the latest results on cometary x-ray emission. Our emphasis will be on understanding the physical mechanism producing the emission, and using this to determine the nature of the cometary coma and solar wind flux. As-observed morphologies, spectra, and light curves will be discussed. We also report on the status of current cometary observations using the new powerful x-ray observatories Chandra and XMM. This work has been graciously supported by grants from the NASA Planetary Astronomy and Astrophysical Data Programs.

  11. Radio search for pulsed emission from X-ray pulsars

    Energy Technology Data Exchange (ETDEWEB)

    delli Santi, F S; Delpino, F [Bologna Univ. (Italy). Ist. di Astronomia; Inzani, P; Sironi, G [Consiglio Nazionale delle Ricerche, Milan (Italy). Lab. di Fisica Cosmica e Tecnologie Relative; Mandolesi, N; Morigi, G [Consiglio Nazionale delle Ricerche, Bologna (Italy). Lab. TESRE

    1981-05-01

    An experiment has been performed at 325 MHz, with a 10 m tracking dish, for the search of pulsed radio emission associated with X-ray pulsars. No evidence of radio pulses has been found in the four sources investigated, although the radio pulsar PSR 0329 + 54, used a testing object, has been detected successfully.

  12. X-ray emission from hot subdwarfs with compact companions

    Directory of Open Access Journals (Sweden)

    Esposito P.

    2013-03-01

    Full Text Available We review the X-ray observations of hot subdwarf stars. While no X-ray emission has been detected yet from binaries containing B-type subdwarfs, interesting results have been obtained in the case of the two luminous O-type subdwarfs HD 49798 and BD + 37° 442. Both of them are members of binary systems in which the X-ray luminosity is powered by accretion onto a compact object: a rapidly spinning (13.2 s and massive (1.28  M⊙ white dwarf in the case of HD 49798 and most likely a neutron star, spinning at 19.2 s, in the case of BD + 37° 442. Their study can shed light on the poorly known processes taking place during common envelope evolutionary phases and on the properties of wind mass loss from hot subdwarfs.

  13. Applications of particle induced X-ray emission

    International Nuclear Information System (INIS)

    Akselsson, K. R.

    1978-01-01

    In Particle Induced X-ray Emission (PIXE) analysis samples are bombarded by protons or α-particles of a few MeV/u. The induced characteristic x-rays are detected with a x-ray detector e.g. a Si(Li)-detector. The energies of the x-ray peaks are characteristic for the elements in the samples and the intensities of the x-ray transitions are proportional to the abundances of the elements. The research area which first attracted those of us working with PIXE was the study of sources, transport and deposition of airborne particulates. Sources, transport, wet deposition, other applications where PIXE is already known to be competitive are trace elemental analysis of water below the ppb-level and analyses requiring a space resolution of 1-10μ. However, there is still much to do for physicists in developing the full potential of low-energy accelerators as analytical tools in multidisciplinary teams. (JIW)

  14. X-ray emission from the Pleiades cluster

    Science.gov (United States)

    Agrawal, P. C.; Singh, K. P.; Riegler, G. R.

    1983-01-01

    The detection and identification of H0344+24, a new X-ray source located in the Pleiades cluster, is reported, based on observations made with HEAO A-2 low-energy detector 1 in the 0.15-3.0-keV energy band in August, 1977. The 90-percent-confidence error box for the new source is centered at 03 h 44.1 min right ascension (1950), near the center star of the 500-star Pleiades cluster, 25-eta-Tau. Since no likely galactic or extragalactic source of X-rays was found in a catalog search of the error-box region, identification of the source with the Pleiades cluster is considered secure. X-ray luminosity of the source is calculated to be about 10 to the 32nd ergs/sec, based on a distance of 125 pc. The X-ray characteristics of the Pleiades stars are discussed, and it is concluded that H0344+24 can best be explained as the integrated X-ray emission of all the B and F stars in the cluster.

  15. A laboratory-based hard x-ray monochromator for high-resolution x-ray emission spectroscopy and x-ray absorption near edge structure measurements

    Energy Technology Data Exchange (ETDEWEB)

    Seidler, G. T., E-mail: seidler@uw.edu; Mortensen, D. R.; Remesnik, A. J.; Pacold, J. I.; Ball, N. A.; Barry, N.; Styczinski, M.; Hoidn, O. R. [Physics Department, University of Washington, Seattle, Washington 98195-1560 (United States)

    2014-11-15

    We report the development of a laboratory-based Rowland-circle monochromator that incorporates a low power x-ray (bremsstrahlung) tube source, a spherically bent crystal analyzer, and an energy-resolving solid-state detector. This relatively inexpensive, introductory level instrument achieves 1-eV energy resolution for photon energies of ∼5 keV to ∼10 keV while also demonstrating a net efficiency previously seen only in laboratory monochromators having much coarser energy resolution. Despite the use of only a compact, air-cooled 10 W x-ray tube, we find count rates for nonresonant x-ray emission spectroscopy comparable to those achieved at monochromatized spectroscopy beamlines at synchrotron light sources. For x-ray absorption near edge structure, the monochromatized flux is small (due to the use of a low-powered x-ray generator) but still useful for routine transmission-mode studies of concentrated samples. These results indicate that upgrading to a standard commercial high-power line-focused x-ray tube or rotating anode x-ray generator would result in monochromatized fluxes of order 10{sup 6}–10{sup 7} photons/s with no loss in energy resolution. This work establishes core technical capabilities for a rejuvenation of laboratory-based hard x-ray spectroscopies that could have special relevance for contemporary research on catalytic or electrical energy storage systems using transition-metal, lanthanide, or noble-metal active species.

  16. X-ray emission lines from photoionized plasmas

    International Nuclear Information System (INIS)

    Liedahl, D.A.

    1992-11-01

    Plasma emission codes have become a standard tool for the analysis of spectroscopic data from cosmic X-ray sources. However, the assumption of collisional equilibrium, typically invoked in these codes, renders them inapplicable to many important astrophysical situations, particularly those involving X-ray photoionized nebulae, which are likely to exist in the circumsource environments of compact X-ray sources. X-ray line production in a photoionized plasma is primarily the result of radiative cascades following recombination. Through the development of atomic models of several highly-charged ions, this work extends the range of applicability of discrete spectral models to plasmas dominated by recombination. Assuming that ambient plasma conditions lie in the temperature range 10 5 --10 6 K and the density range 10 11 --10 16 cm -3 , X-ray line spectra are calculated over the wavelength range 5--45 angstrom using the HULLAC atomic physics package. Most of the work focuses on the Fe L-shell ions. Line ratios of the form (3s-2p)/(3d-2p) are shown to characterize the principal mode of line excitation, thereby providing a simple signature of photoionization. At electron densities exceeding 10 12 cm -3 , metastable state populations in the ground configurations approach their LTE value, resulting in the enrichment of the Fe L-shell recombination spectrum and a set of density-sensitive X-ray line ratios. Radiative recombination continua and emission lines produced selectively by Δn = 0 dielectronic recombination are shown to provide two classes of temperature diagnostics. Because of the extreme overionization, the recombination continua are expected to be narrow (ΔE/E much-lt 1), with ΔE = kT. Dielectronic recombination selectively drives radiative transitions that originate on states with vacancies in the 2s subshell, states that are inaccessible under pure RR population kinetics

  17. The X-ray emission spectrum of gaseous acetylene

    International Nuclear Information System (INIS)

    Brammer, R.; Rubensson, J.E.; Wassdahl, N.; Nordgren, J.

    1987-01-01

    The X-ray emission spectrum of acetylene in the gas phase has been recorded using a 10 m grazing incidence spectrometer. Analysis of the spectrum is made based on calculations of total energies, potential curves and Franck-Condon vibrational intensities. Four emission bands are seen with the 1 π u band exhibiting vibrational structure. Analysis of the vibrations gives the CIs ionization energy. High energy satellite structure is observed and interpreted. (orig.)

  18. Fast Fiber-Coupled Imaging of X-rays Events, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — HyperV Technologies Corp. proposes to construct a long-record-length, fiber-coupled, fast imaging diagnostic for recording X-ray back-lit material flows and X-ray...

  19. X-ray emission and the winds of cataclysmic variables

    International Nuclear Information System (INIS)

    Cordova, F.A.

    1985-01-01

    X-ray and ultraviolet observations of cataclysmic variable stars reveal a variety of exotic behavior - pulsations, winds, and episodic outbursts - are these related, what do they tell us about the nature of the outburst, about the environment of the accreting white dwarf. The author summarizes the observed changes in the x-ray and uv continuum and spectral features through the outbursts of the dwarf novae. The author then discusses how the modeling of these data have refined our ideas about the location and nature of the emissions, and the source of the outbursts. The author shows how comparisons of the x-ray and uv properties of cataclysmic variables with similar phenomena in other astronomical systems - the solar corona, OB stars, and Be stars - suggest ways in which the x-ray and uv emissions in CVs may be related, and point to further, specific observations that would elucidate our understanding of the behavior and role of the white dwarf in the outburst. 26 references

  20. X-ray emission characteristics of foam target plasmas

    International Nuclear Information System (INIS)

    Fronya, A.A.; Borisenko, N.G.; Chernodub, M.L.; Merkuliev, Yu.A.; Osipov, M.V.; Puzyrev, V.N.; Sahakyan, A.T.; Starodub, A.N.; Vasin, B.L.; Yakushev, O.F.

    2010-01-01

    Complete text of publication follows. Experimental results of laser radiation interaction with a foam targets are presented. The spatial, temporal and energy characteristics of x-ray plasma radiation have been investigated. The pinhole-camera and Schwarzschild objective have been used for the plasma image formation in different spectral ranges. The plasma image is registered by the Schwarzschild objective in a narrow spectral range 180 - 200 A. Spectral characteristics of x-ray radiation registered by pinhole-camera have been defined by means outer filters. The use of the filters with different transmission curves allowed one the determine the localization of x-ray radiation with fixed wavelength. Spatial resolution accounts 16 μm in the pinhole-camera diagnostic channel and 2.5 μm in the Schwarzschild objective diagnostic channel. The plasma images in the intrinsic x-ray radiation show that the emission area in the transverse direction with respect to the direction of the propagating heating radiation exceeds the focal spot size. This fact indicates that the target heating in the transverse direction is due to internal energy of the created plasma. The average value of plasma electron temperature is ∼ 0.4 - 1.4 keV. Acknowledgements. The work is partly supported by the Russian Foundation for Basic Researches, grant no. 10-02-00113 and by Federal Target Program 'Research and scientific-pedagogical cadres of Innovative Russia' (grant 2009-1.1-122-052-025).

  1. Electron emission regulator for an x-ray tube filament

    International Nuclear Information System (INIS)

    Daniels, H.E.; Randall, H.G.

    1982-01-01

    An x-ray tube ma regulator has an scr phase shift voltage regulator supplying the primary winding of a transformer whose secondary is coupled to the x-ray tube filament. Prior to initiation of an x-ray exposure, the filament is preheated to a temperature corresponding substantially to the electron emissivity needed for obtaining the desired tube ma during an exposure. During the preexposure interval, the phase shift regulator is controlled by a signal corresponding to the sum of signals representative of the voltage applied to the filament transformer, the desired filament voltage and the space charge compensation needed for the selected x-ray tube anode to cathode voltage. When an exposure is initiated, control of the voltage regulator is switched to a circuit that responds to the tube current by controlling the amount of phase shift and, hence, the voltage supplied to the transformer. Transformer leakage current compensation is provided during the exposure interval with a circuit that includes an element whose impedance is varied in accordance with the anode-to-cathode voltage setting so the element drains off tube current as required to cancel the effect of leakage current variations

  2. Hard X-ray emission spectroscopy with pink beam

    Energy Technology Data Exchange (ETDEWEB)

    Kvashnina, Kristina O.; Rossberg, Andre; Exner, Joerg; Scheinost, Andreas C. [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Molecular Structures

    2017-06-01

    Valence-band X-ray emission spectroscopy (XES) with a ''pink beam'', i.e. a beam with large energy bandwidth produced by a double-multilayer monochromator, is introduced here to overcome the weak count rate of monochromatic beams produced by conventional double-crystal monochromators. Our results demonstrate that - in spite of the large bandwidth in the order of 100 eV - the high spectral resolution of the Johann-type spectrometer is maintained, while the two orders of magnitude higher flux greatly reduces the required counting time. The short working distance Johann-type X-ray emission spectrometer and multilayer monochromator is available at ROBL.

  3. Quantifying the Exospheric Component of Soft X-ray Emission

    Science.gov (United States)

    Kuntz, Kip; Collier, Michael R.; Snowden, Steven L.; Robertson, Ina; Hansen, Kenneth; Cravens, Thomas

    2007-01-01

    High charge state heavy ions in the solar wind exchange charge with ambient neutral gas. This process creates a product ion in an excited state. During the radiative cascade process, EUV and X-ray photons are emitted with energies in the range of about 100 eV to 1 keV. Because the terrestrial exospheric density at the nominal magnetopause location is relatively high, approx. 10 cu cm, solar wind charge exchange, or SWCX, can be observed by Earth-orbiting soft X-ray instruments such as the ROSAT Position Sensitive Proportional Counters (PSPC). In this presentation, we will compare simulated and observed soft Xray emission during an event on August 18-19, 1991 and discuss the role of exospheric SWCX emission for this and other events.

  4. Scaling of x-ray emission and ion velocity in laser produced Cu ...

    Indian Academy of Sciences (India)

    Laser plasma; x-ray emission; conversion efficiency; ion velocities. ... fits from this kind of optimization studies are in the fields of x-ray lithography, x-ray lasers etc. .... formula between the x-ray conversion rate versus different parameters of the ...

  5. Relative probabilities of the uranium isotopes for thorium x-ray emission and fluorescence of uranium x-rays

    International Nuclear Information System (INIS)

    Parker, J.L.

    1991-01-01

    Both thorium x-rays from decaying uranium isotopes and self-fluoresced uranium x-rays are prominent in high-resolution gamma-ray spectra of uranium-bearing materials. Useful application of the information carried by those x-rays has been curtailed because the probabilities of the uranium isotopes for thorium x-ray emission and for uranium x-ray fluorescence have not been known. By analyzing enrichment-meter geometry spectra from uranium oxide standards whose enrichments ranged from 0.7% to 91%, relative values, primarily, have been obtained for the probabilities of both processes. Thorium x-ray emission is very heavily dominated by 235 U. In all ordinarily occurring uranium isotopic distributions, thorium x-rays may be used as a valid 235 U signature. The probability for a thorium K α1 x-ray to be emitted in the decay of a 235 U atom is 0.048 ±0.002. In infinitely thick uranium oxide materials, the relative ratios of effectiveness for self-fluorescence, on a per unit mass basis, are approximately 234 U : 235 U : 236 U : 238 U = 1.13 : 1.00 : 0.52 : 0.028. on a per decay basis, the approximate ratios are 0.00039 : 1.00 : 0.017 : 0.18. These results imply that, contrary to what has often been stated, gamma rays are far more important than alpha particles in the self-fluorescence of uranium. Because of the importance of gamma-ray self-fluorescence, the uranium x-ray yield will be somewhat influenced by the size, shape, and composition of the materials. 4 refs., 1 fig

  6. Simultaneous emissions of X-rays and microwaves from long laboratory sparks and downward lightning leaders

    Science.gov (United States)

    Montanya, J.; Oscar, V. D. V.; Tapia, F. F.

    2017-12-01

    Since the discovery of the Terrestrial Gamma-ray Flashes more than 20 years ago, investigations on high energy emissions from natural lightning and high voltage laboratory sparks gained significant interest. X-ray emissions from lightning as well from high voltage laboratory sparks have in common the role played by negative leaders/streamers. On the other hand, negative leaders are well known to produce much more VHF and microwave radiation than positive leaders. Moreover, in previous works, microwave emissions from lightning leaders have been attributed to Bremsstrahlung process. The object of this work is to investigate if X-rays and RF microwave emissions share the same origin. We present simultaneous measurements of X-rays and microwaves in high voltage sparks and natural lightning. The instrumentation consists on a NaI(Tl) and LaBr3 scintillation detectors and two different receivers. One is fix tuned at 2.4 GHz with a bandwidth of 5.5 MHz. The second can be tuned at any frequency up to 18 GHz with different selectable bandwidths of 10 MHz, 40 MHz and 100 MHz. In the laboratory, results have shown that all the sparks presented microwave radiation before the breakdown of the gap, either X-rays were detected or not. In the cases where X-rays were identified, microwave emissions peaked at the same time (in the microsecond scale). We found that the power amplitudes of the microwave emissions are related to the applied voltage to the gap. In the same configuration, those cases where X-rays were detected microwave emissions presented higher power levels. The results suggest that in some part of the discharge electrons are very fast accelerated allowing, in some cases, to reach enought energy to produce X-rays. In the field, we have found similar results. On 13th of June of 2015 a bipolar cloud-to-ground flash struck 200 m close to the Eagle Nest instrumented tower (Spanish Pyrenees, 2536 m ASL). The flash presented four strokes and, in all of them, microwave

  7. Colliding Stellar Winds Structure and X-ray Emission

    Science.gov (United States)

    Pittard, J. M.; Dawson, B.

    2018-04-01

    We investigate the structure and X-ray emission from the colliding stellar winds in massive star binaries. We find that the opening angle of the contact discontinuity (CD) is overestimated by several formulae in the literature at very small values of the wind momentum ratio, η. We find also that the shocks in the primary (dominant) and secondary winds flare by ≈20° compared to the CD, and that the entire secondary wind is shocked when η ≲ 0.02. Analytical expressions for the opening angles of the shocks, and the fraction of each wind that is shocked, are provided. We find that the X-ray luminosity Lx∝η, and that the spectrum softens slightly as η decreases.

  8. X-ray/UV variability and the origin of soft X-ray excess emission from II Zw 177

    Science.gov (United States)

    Pal, Main

    We study a detailed broad-band X-ray/UV emission from the narrow line Seyfert 1 galaxy II Zw 177 based on two XMM-Newton and single Swift/XRT observations. Both XMM-Newton observations show the soft X-ray excess emission below 2 keV when the best-fit 2 - 10 keV power law is extrapolated down to 0.3 keV. We find the blurred reflection from an ionized accretion disc and Comptonized disc emission both describe the observed soft excess well. We find a remarkable trend of decreasing UV flux with increasing soft X-ray excess and power law emission. We suggest that this could be due to that the external edge of corona hide a fraction of accretion disk. Co-Author: Prof. Gulab C. Dewangan (IUCAA), Prof. Ranjeev Misra (IUCAA), Pramod Kumar (Nanded university)

  9. Fast x-ray fluorescence microtomography of hydrated biological samples.

    Directory of Open Access Journals (Sweden)

    Enzo Lombi

    Full Text Available Metals and metalloids play a key role in plant and other biological systems as some of them are essential to living organisms and all can be toxic at high concentrations. It is therefore important to understand how they are accumulated, complexed and transported within plants. In situ imaging of metal distribution at physiological relevant concentrations in highly hydrated biological systems is technically challenging. In the case of roots, this is mainly due to the possibility of artifacts arising during sample preparation such as cross sectioning. Synchrotron x-ray fluorescence microtomography has been used to obtain virtual cross sections of elemental distributions. However, traditionally this technique requires long data acquisition times. This has prohibited its application to highly hydrated biological samples which suffer both radiation damage and dehydration during extended analysis. However, recent advances in fast detectors coupled with powerful data acquisition approaches and suitable sample preparation methods can circumvent this problem. We demonstrate the heightened potential of this technique by imaging the distribution of nickel and zinc in hydrated plant roots. Although 3D tomography was still impeded by radiation damage, we successfully collected 2D tomograms of hydrated plant roots exposed to environmentally relevant metal concentrations for short periods of time. To our knowledge, this is the first published example of the possibilities offered by a new generation of fast fluorescence detectors to investigate metal and metalloid distribution in radiation-sensitive, biological samples.

  10. Quality assurance challenges in x-ray emission based analyses

    International Nuclear Information System (INIS)

    Papp, T.

    2005-01-01

    Complete text of publication follows. There is a large scatter in the results of X-ray analysis with solid-state detectors suggesting methodological origin. Although the PIXE (proton induced X-ray emission) analytical technique can work without relation to any physics, as was commented at the recent PIXE conference, one could argue that if the same technique is used for measuring physical quantities reveals problems, then perhaps potential methodological issues can not apriory be excluded. We present a simple example which could be interpreted as indications for methodological considerations. Recently an inter-comparison was made of analysis of the spectra measured at the laboratory of the International Atomic Energy Agency (IAEA). Four participating analytical software packages were used to evaluate the X-ray spectra. There are several thin metal samples spectra, for which common energy scale could not be established. The quality of the spectrum can be judged from the line shape. The line shape is parametrized by the full widths at half maximum (FWHM) of a peak and the so-called low energy tailing. Fitting the spectra individually we obtained FWHM squared values at different energies and determined the linear regression parameters. The parameters suggest a rather poor detector performance. It is generally assumed that the (FWHM) 2 values have a first order polynomial form as a function of X-ray energy. Having done a linear regression analysis, we can plot the standard residual, presented in Fig. 1, which clearly shows a three-sigma deviation. The probability to having a three-sigma deviation is 1%. In other words, the probability that these spectra are in accordance with the expected FWHM functional form is less than 1%. The main problem is that, although the composite spectra were analyzed using four different programs, the difficulty in interpreting the spectra was not commented upon by any of the participants in the inter-comparison. (author)

  11. Utilization of synchrotron radiation in analytical chemistry. Soft X-ray emission and absorption spectroscopy

    International Nuclear Information System (INIS)

    Muramatsu, Yasuji

    2015-01-01

    Synchrotron soft X-ray spectroscopy includes three major types of spectroscopy such as X-ray absorption spectroscopy (XAS), X-ray emission spectroscopy (XES), and X-ray photoelectron spectroscopy (XPS). This paper takes up XAS and XES of soft X-rays, and briefly describes the principle. XAS is roughly classified into XANES (X-ray absorption near-edge structure) and EXAFS (extended X-ray absorption fine structure), and XANES is mainly used in the analysis based on XAS of soft X-rays. As the examples of the latest soft X-ray analyses, the following are introduced: (1) bandgap of boron implantation diamond and the local structure of boron, (2) catalytic sites in solid fuel cell carbon electrode, and (3) soft X-ray analysis under atmospheric pressure. (A.O.)

  12. Analysis of sludge using Proton induced X-ray emission

    International Nuclear Information System (INIS)

    Aspiazu, J.; Moreno, E.; Andrade, E.; Miranda, J.; Citalan, S.; Moeller, G.; Soler, F.

    1996-01-01

    Regulations to control the huge amounts of sludge produced by wastewater are needed. Sludge generated in conventional sedimentators or anaerobic digesters were characterized by Proton Induced X-ray Emission (PIXE). It was possible to determine the presence of macro nutrient elements, such as P and K, and secondary nutrients like Ca, S, and Mg. Moreover, heavy elements like Cu, Zn, and Pb were also found. The sludge treatment in anaerobic digesters increased the amount of certain elements Al, Si, S, Cl, and K; decrease in Ca, Ti, and Cu, and no change in V, Cr, and Zn. Possible uses of this sludge are also suggested

  13. Analyais of solar X-ray emission line profiles

    International Nuclear Information System (INIS)

    Burek, A.J.; Marrus, D.M.; Blake, R.L.; Fenimore, E.E.

    1981-01-01

    We report results of the analysis of the X-ray emission line profiles for the Ne X La and Fe XVII 4d 1 P 1 lines produced in an active region that was undergoing a radio and X-ray gradual rise and fall (GRF) in intensity. The spectra were obtained with collimated Bragg spectrometers launched on a rocket from White Sands Missile Range on 1976 March 26. Using a crystal of ammonium acid phthalate, we have fully resolved the Ne X La and Fe XVII 4d 1 P 1 lines, permitting an accurate determinination of the Ne X La intensity and allowing Doppler broadened profiles for lines formed from ions having greatly different atomic mass and charge to be measured. An isothermal model derived from the Ne IX/Ne X resonance line intensity ratio gives an electron temperature of 3.4 x 10 6 K. An isothermal model, however, fails to account for the intensities of all lines and continuum observed. All multitemperature models that do reproduce the observed relative line intensities require the presence of a hot plasma component with an electron temperature in excess of 5 x 10 6 K. The presence of a high temperature component is also suggested by the measured line to continuum ratio of 3.6 in the 12--15 A wavelength interval. Interpretation of the line profiles in terms of a multitemperature model requires an rms turbulence velocity of 48 +- 15 km s -1 for Fe XVII 1 P 1 and 74 +- 54 km s - 2exclamation for Ne X La at the 95% confidence level. Collimated scans across the active region show the presence of a compact source of intense X-ray emission close to the magnetic neutral line, which is very probably the GRF plasma

  14. Studies of soft x-ray emission during solar flares

    International Nuclear Information System (INIS)

    Anandaram, M.N.

    1973-01-01

    Solar flare soft x-ray emission from 0.5 A to 8.5 A was observed during 1967-68 by Bragg crystal (LiF and EDDT) spectrometers aboard the OSO-4 satellite and also by NRL broad-band ionization detectors aboard the OGO-4 satellite. In this work, instrumental parameters for the LiF crystal spectrometer based on experimental values have been determined and used in the data analysis. The total continuum emission in the 0.5 to 3 A and the 1 to 8 A broad band segments has been determined from OGO-4 data for 21 flares. In doing this, a simple and approximate method of converting the total emission based on the gray body approximation (in which the OGO-4 data are reported) to one based on the thermal continuum spectrum has been developed. (author)

  15. Weak hard X-ray emission from broad absorption line quasars: evidence for intrinsic X-ray weakness

    International Nuclear Information System (INIS)

    Luo, B.; Brandt, W. N.; Scott, A. E.; Alexander, D. M.; Gandhi, P.; Stern, D.; Teng, S. H.; Arévalo, P.; Bauer, F. E.; Boggs, S. E.; Craig, W. W.; Christensen, F. E.; Comastri, A.; Farrah, D.; Hailey, C. J.; Harrison, F. A.; Koss, M.; Ogle, P.; Puccetti, S.; Saez, C.

    2014-01-01

    We report NuSTAR observations of a sample of six X-ray weak broad absorption line (BAL) quasars. These targets, at z = 0.148-1.223, are among the optically brightest and most luminous BAL quasars known at z < 1.3. However, their rest-frame ≈2 keV luminosities are 14 to >330 times weaker than expected for typical quasars. Our results from a pilot NuSTAR study of two low-redshift BAL quasars, a Chandra stacking analysis of a sample of high-redshift BAL quasars, and a NuSTAR spectral analysis of the local BAL quasar Mrk 231 have already suggested the existence of intrinsically X-ray weak BAL quasars, i.e., quasars not emitting X-rays at the level expected from their optical/UV emission. The aim of the current program is to extend the search for such extraordinary objects. Three of the six new targets are weakly detected by NuSTAR with ≲ 45 counts in the 3-24 keV band, and the other three are not detected. The hard X-ray (8-24 keV) weakness observed by NuSTAR requires Compton-thick absorption if these objects have nominal underlying X-ray emission. However, a soft stacked effective photon index (Γ eff ≈ 1.8) for this sample disfavors Compton-thick absorption in general. The uniform hard X-ray weakness observed by NuSTAR for this and the pilot samples selected with <10 keV weakness also suggests that the X-ray weakness is intrinsic in at least some of the targets. We conclude that the NuSTAR observations have likely discovered a significant population (≳ 33%) of intrinsically X-ray weak objects among the BAL quasars with significantly weak <10 keV emission. We suggest that intrinsically X-ray weak quasars might be preferentially observed as BAL quasars.

  16. Fast Soft X-ray Images of MHD Phenomena in NSTX

    International Nuclear Information System (INIS)

    Bush, C.E.; Stratton, B.C.; Robinson, J.; Zakharov, L.E.; Fredrickson, E.D.; Stutman, D.; Tritz, K.

    2008-01-01

    A variety of magnetohydrodynamic (MHD) phenomena have been observed on the National Spherical Torus Experiment (NSTX). Many of these affect fast particle losses, which are of major concern for future burning plasma experiments. Usual diagnostics for studying these phenomena are arrays of Mirnov coils for magnetic oscillations and PIN diode arrays for soft x-ray emission from the plasma core. Data reported here are from an unique fast soft x-ray imaging camera (FSXIC) with a wide-angle (pinhole) tangential view of the entire plasma minor cross section. The camera provides a 64x64 pixel image, on a CCD chip, of light resulting from conversion of soft x-rays incident on a phosphor to the visible. We have acquired plasma images at frame rates of 1-500 kHz (300 frames/shot), and have observed a variety of MHD phenomena: disruptions, sawteeth, fishbones, tearing modes, and ELMs. New data including modes with frequency > 90 kHz are also presented. Data analysis and modeling techniques used to interpret the FSXIC data are described and compared, and FSXIC results are compared to Mirnov and PIN diode array results.

  17. Nuclear X-ray emission after fusion of heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Berner, Christian; Muecher, Dennis; Gernhaeuser, Roman; Faestermann, Thomas [Technische Universitaet Muenchen, Lehrstuhl E12 (Germany); Henning, Walter [Technische Universitaet Muenchen, Lehrstuhl E12 (Germany); Argonne National Laboratory (United States); Morita, Kosuke; Morimoto, Kouji; Kaji, Daija [RIKEN, Research Group for Superheavy Elements (Japan)

    2015-07-01

    The goal is to establish in-beam K-X-ray spectroscopy as a sensitive tool to identify super heavy elements (SHEs) produced in fusion reactions via their proton number. SHEs, formed after cold or hot fusion, are usually identified via the alpha-decay products, which have to be connected to well-known elements. In case of hot fusion, the daughter nuclei quickly undergo spontaneous fission, so that the identification of the produced SHEs is difficult. Using the hot fusion approach in our first test experiments, the resultant products will be analysed by the gas-filled GARIS separator at the RILAC facility at RIKEN. As the X-ray detector is required to have superior energy and timing resolution to best identify the rare events at highest masses and to supress random coincidences as sufficient as possible, we chose a thin and planar geometry, which also reduces the damage caused by fast neutrons. We show first measurements using the MINIBALL Ge array at Munich. Additionally we report on our feasibility studies and on first tests using the new detector at high count rates together with a powerful DAQ system and transistor reset preamplifiers.

  18. Doppler-shift assisted fast ion spectroscopy: a case study for X-ray emission from 277 MeV/u Pb[81+] ions

    International Nuclear Information System (INIS)

    Mokler, P.H.; Stoehlker, T.; Kozhuharov, C.; Moshammer, R.; Rymuza, P.; Stachura, Z.; Warczak, A.

    1994-09-01

    Utilizing the different information from spatially separated segments of high-granular photon detectors the measured (LAB) energy of photons emitted by fast moving ions can be corrected individually for the Doppler effect according to the particular observation angles of each detector segment. By a redundant fitting procedure the center of mass photon energy can be determined with high precision. This new Doppler-shift assisted spectroscopy is explained for the case study of 277.4 MeV/u Pb 82+ ions colliding with a N 2 -gas target at the heavy ion storage ring ESR. Spectroscopic information for hydrogenic Pb 81+ ions is given for the ground-state transitions, for the Balmer transitions, as well as for the total K-binding energy. (orig.)

  19. Application of X-ray emission techniques for monitoring environmental pollution

    International Nuclear Information System (INIS)

    Bernasconi, G.; Danesi, P.R.; Dargie, M.; Haselberger, N.; Markowicz, A.; Tajani, A.

    1997-01-01

    X-ray emission techniques are versatile and powerful methods used for multielement non-destructive analysis. They include X-ray fluorescence (XRF), particle induced X-ray emission (PIXE), scanning electron microscopy combined with X-ray spectrometry and electron probe microanalysis (EPMA). Since many years the IAEA has utilised and promoted these techniques for the analysis of environmental, biological and geological samples. In this paper recent progress at our laboratory in selected aspects related to the application of X-ray emission techniques is briefly overviewed. (authors)

  20. X-ray emission as a diagnostic from pseudospark-sourced electron beams

    Energy Technology Data Exchange (ETDEWEB)

    Bowes, D., E-mail: david.bowes@strath.ac.uk [Department of Physics, SUPA, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Yin, H.; He, W.; Zhang, L.; Cross, A.W.; Ronald, K.; Phelps, A.D.R. [Department of Physics, SUPA, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Chen, D.; Zhang, P. [Computed Tomography Lab, School of Mathematical Sciences, Capital Normal University, Beijing 100048 (China); Chen, X.; Li, D. [Department of Electronic Engineering, Queen Mary University of London, London E1 4NS (United Kingdom)

    2014-09-15

    X-ray emission has been achieved using an electron beam generated by a pseudospark low-pressure discharge and utilised as a diagnostic for beam detection. A 300 A, 34 kV PS-sourced electron beam pulse of 3 mm diameter impacting on a 0.1 mm-thick molybdenum target generated X-rays which were detected via the use of a small, portable X-ray detector. Clear X-ray images of a micro-sized object were captured using an X-ray photodetector. This demonstrates the inducement of proton induced X-ray emission (PIXE) not only as an indicator of beam presence but also as a future X-ray source for small-spot X-ray imaging of materials.

  1. Neutron and X-ray emission studies in a low energy plasma focus

    Energy Technology Data Exchange (ETDEWEB)

    Zakaullah, M. [Quaid-i-Azam Univ., Islamabad (Pakistan). Dept. of Physics; Murtaza, G. [Quaid-i-Azam Univ., Islamabad (Pakistan). Dept. of Physics; Qamar, S. [Quaid-i-Azam Univ., Islamabad (Pakistan). Dept. of Physics; Ahmad, I. [Quaid-i-Azam Univ., Islamabad (Pakistan). Dept. of Physics; Beg, M.M. [Quaid-i-Azam Univ., Islamabad (Pakistan). Dept. of Physics

    1996-03-01

    In a low energy Mather-type plasma focus energized by a single 32 {mu}F capacitor, the X-ray and neutron emission is investigated using time-integrated and time-resolved detectors. The X-ray emission profile has a width (FWHM) of 40-50 ns. The neutron emission profile is broader compared to the X-ray emission profile and also delayed by 30-40 ns. To identify different regimes of X-ray emission, an X-ray pin-hole camera along with different absorption filters is employed. While the X-ray emission is high within a narrow pressure range of 2.0-2.5 mbar, the neutron emission is intense for a wider range of 1.0-4.5 mbar. The intense X-ray emission seems to originate from the axially moving shock wave. These results also indicate rather different production mechanisms for X-ray and neutron emission. Also on comparing the X-ray images with Al(2 {mu}m), Al(5 {mu}m), Al(9 {mu}m) filters, we find that the bulk of X-rays from the focus filament have energies less than 2 keV. (orig.).

  2. NuSTAR Hard X-ray Survey of the Galactic Center Region. I. Hard X-ray Morphology and Spectroscopy of the Diffuse Emission

    DEFF Research Database (Denmark)

    Mori, Kaya; Hailey, Charles J.; Krivonos, Roman

    2015-01-01

    We present the first sub-arcminute images of the Galactic Center above 10 keV, obtained with NuSTAR. NuSTAR resolves the hard X-ray source IGR J17456-2901 into non-thermal X-ray filaments, molecular clouds, point sources, and a previously unknown central component of hard X-ray emission (CHXE). Nu...

  3. Potpourri of proton induced x-ray emission analyses

    International Nuclear Information System (INIS)

    Mangelson, N.F.; Nielson, K.K.; Eatough, D.J.; Hansen, L.D.

    1974-01-01

    A proton-induced x-ray emission analysis (PIXE) system using 2-MeV protons was developed. Measurements are being made in connection with several research projects. A study is being conducted to provide ecological baseline information in the region of the Navajo and the proposed Kaiparowits coal-fired electric generating stations. Trace-element measurements in this study are reported on air-particulate samples, small rodent tissues, soils, and plants. In another study air particulates collected near a source of SO 2 are extracted from the collection filter with an HCl solution and sulfate and sulfite ions are determined by calorimetric methods. The extraction solution is also analyzed by PIXE to determine the elemental composition. The latter information is necessary for an understanding of possible interferences with the calorimetric method and also indicates the heavy metals emitted by the source. Studies on human autopsy tissues, archeological artifacts, and in regular graduate and undergraduate laboratory classes are mentioned briefly

  4. Soft X-ray emission studies of biomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Kurmaev, E.Z. E-mail: kurmaev@ifmlrs.uran.ru; Werner, J.P.; Moewes, A.; Chiuzbaian, S.; Bach, M.; Ching, W.-Y.; Motozaki, W.; Otsuka, T.; Matsuya, S.; Endo, K.; Neumann, M

    2004-07-01

    Soft X-ray fluorescence measurements are used to characterize three groups of biomaterials: Vitamin B{sub 12} and derivatives, antioxidants (aspirin and paracetamol), and human teeth. We show that the chemical bonding in Vitamin B{sub 12} is characterized by the strong Co-C bond and the relatively weak Co-N bond. The Co-C bond in cyanocobalamin is found to be stronger than that of methylcobalamin leading to their different biological activity. The chemical bonding of paracetamol and aspirin is characterized by the formation of oxygen lone-pair {pi}-orbitals, which can neutralize free radicals and therefore be related to antioxidant activity of these compounds. Carbon K{alpha} emission spectra of a caries lesion suggest that the CaCO{sub 3} like phase exists in sound enamel and that a selective loss of carbonate occurs during the early stages of a caries attack.

  5. Sawtooth-like X-ray emission observed in EBIT

    International Nuclear Information System (INIS)

    Radtke, R.; Biedermann, C.; Bachmann, P.

    2003-01-01

    The evolution of a mixture of highly charged Ar and Ba ions was measured in an electron beam ion trap (EBIT) by recording the characteristic X-ray emission from trapped ions. A special feature in the spectra are sawtooth-like intensity variations caused by a periodic collapse of the ion inventory in the trap. The effect requires favorable conditions to become present and is very sensitive to the trapping conditions. Analysis of the measurements is based on a time-dependent calculation of the trapping process. Simulations show that sawtooth activity results from the feedback between the low-Z Ar and high-Z Ba ions (Hopf bifurcation). Sawtooth spectra open up a spectroscopic method to test theoretical EBIT models and probe the dynamics in ion traps and sources

  6. Soft X-ray emission studies of biomaterials

    International Nuclear Information System (INIS)

    Kurmaev, E.Z.; Werner, J.P.; Moewes, A.; Chiuzbaian, S.; Bach, M.; Ching, W.-Y.; Motozaki, W.; Otsuka, T.; Matsuya, S.; Endo, K.; Neumann, M.

    2004-01-01

    Soft X-ray fluorescence measurements are used to characterize three groups of biomaterials: Vitamin B 12 and derivatives, antioxidants (aspirin and paracetamol), and human teeth. We show that the chemical bonding in Vitamin B 12 is characterized by the strong Co-C bond and the relatively weak Co-N bond. The Co-C bond in cyanocobalamin is found to be stronger than that of methylcobalamin leading to their different biological activity. The chemical bonding of paracetamol and aspirin is characterized by the formation of oxygen lone-pair π-orbitals, which can neutralize free radicals and therefore be related to antioxidant activity of these compounds. Carbon Kα emission spectra of a caries lesion suggest that the CaCO 3 like phase exists in sound enamel and that a selective loss of carbonate occurs during the early stages of a caries attack

  7. X-ray emission in heavy ion collisions. Final report

    International Nuclear Information System (INIS)

    Watson, R.L.

    1984-01-01

    A detailed accounting of the yearly activities of the research program entitled X-ray Emission in Heavy Ion Collisions may be found in the annual progress reports submitted in accordance with the terms of the contract. The principal goals of the program to be summarized herein were (a) to delineate the mechanisms whereby highly ionized atoms in the condensed phase deexcite and return to charge neutrality, (b) to investigate the charge quenching processes acting to reduce the charge states of highly ionized projectiles, and (c) to attain a better understanding of the interactions occurring between highly charged ions and solid surfaces. These projects all relate to problems associated with the ultimate application of controlled thermonuclear reactions as a practical energy source

  8. Discovery of Hard Nonthermal Pulsed X-Ray Emission from the Anomalous X-Ray Pulsar 1E 1841-045

    NARCIS (Netherlands)

    Kuiper, L.; Hermsen, W.; Méndez, R.M.

    2004-01-01

    We report the discovery of nonthermal pulsed X-ray/soft gamma-ray emission up to ~150 keV from the anomalous 11.8 s X-ray pulsar AXP 1E 1841-045 located near the center of supernova remnant Kes 73 using Rossi X-Ray Timing Explorer (RXTE) Proportional Counter Array and High Energy X-Ray Timing

  9. Signatures of Synchrotron: Low-cutoff X-ray emission and the hard X-ray spectrum of Cas A

    Science.gov (United States)

    Stage, Michael D.; Fedor, Emily Elizabeth; Martina-Hood, Hyourin

    2018-06-01

    In soft X-rays, bright, young Galactic remnants (Cas A, Kepler, Tycho, etc.) present thermal line emission and bremsstrahlung from ejecta, and synchrotron radiation from the shocks. Their hard X-ray spectra tend to be dominated by power-law sources. However, it can be non-trivial to discriminate between contributions from processes such as synchrotron and bremsstrahlung from nonthermally accelerated electrons, even though the energies of the electrons producing this radiation may be very different. Spatially-resolved spectroscopic analysis of 0.5-10 keV observations with, e.g., Chandracan provide leverage in identifying the processes and their locations. Previously, Stage & Allen (2006), Allen & Stage (2007) and Stage & Allen (2011) identified regions characterized by high-cutoff synchrotron radiation. Extrapolating synchrotron model fits to the emission in the Chandra band, they estimated the synchrotron contribution to the hard X-ray spectrum at about one-third the observed flux, fitting the balance with nonthermal bremsstrahlung emission produced by nonthermal electrons in the ejecta. Although it is unlikely this analysis missed regions of the highest-cutoff synchrotron emission, which supplies the bulk of the synchrotron above 15 keV, it may have missed regions of lower-cutoff emission, especially if they are near bright ejecta and the reverse shock. These regions cannot explain the emission at the highest energies (~50 keV), but may make significant contributions to the hard spectrum at lower energies (~10 keV). Using the technique described in Fedor, Martina-Hood & Stage (this meeting), we revisit the analysis to include regions that may be dominated by low-cutoff synchrotron, located in the interior of the remnant, and/or correlated with the reverse shock. Identifying X-ray emission from accelerated electrons associated with the reverse-shock would have important implications for synchrotron and non-thermal bremsstrahlung radiation above the 10 keV.

  10. Optimization of neon soft X-ray emission from 200 J plasma focus device for application in soft X-ray lithography

    International Nuclear Information System (INIS)

    Kalaiselvi, S.M. P.; Tan, T.L.; Talebitaher, A.; Lee, Paul; Rawat, R.S.

    2014-01-01

    The Fast Miniature Plasma Focus (FMPF) device is basically made up of coaxial electrodes with centrally placed anode and six cathode rods surrounding them concentrically. They are enclosed in a vacuum chamber, filled with low pressure operating gas. However, in our experiments, these cathode rods were removed to investigate the influence of them on neon soft X-ray (SXR) and hard X-ray (HXR) emission from the device. On removal of cathode rods, the cathode base plate serves as cathode and the plasma sheath is formed between the anode and the base plate of cathode. Neon was used as the operating gas for our experiments and the FMPF device used is of 235 J energy capacities. The experimental results showed that the FMPF device was able to focus better and the SXR emission efficiency was five times higher without cathode rods than with cathode rods. On the contrary, HXR emission did not vary with and without cathode rods. This observed phenomenon was further cross-checked through imaging of plasma dynamics, with and without cathode rods. FMPF device consists of 4 Pseudo Spark Gap (PSG) switches, which need to operate synchronously to deliver high voltage from capacitors to the anode. It was also seen that, the presence or absence of cathode rods also influence the synchronous operation of PSG switches. It also implies that this is one definite way to optimize the SXR emission from the FMPF device. This study reveals an important finding that, cathode rods play a vital role in the formation of plasma sheath with consequential influence on the radiation emission from plasma focus devices. Enhancement of the X-ray emission from this device is definitely a stepping stone in the realization of this device for industrial applications such as X-ray lithography for semiconductor industries. (author)

  11. Fast synchrotron X-ray tomography study of the rod packing structures

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Xiaodan; Xia Chengjie; Sun Haohua; Wang Yujie [Department of Physics, Shanghai Jiao Tong University, 800 Dong Chuan Road, Shanghai 200240 (China)

    2013-06-18

    We present a fast synchrotron X-ray tomography study of the packing structures of rods under tapping. Utilizing the high flux of the X-rays generated from the third-generation synchrotron source, we can complete a tomography scan within several seconds, after which the three-dimensional (3D) packing structure can be obtained for the subsequent structural analysis. Due to the high-energy nature of the X-ray beam, special image processing steps including image phase-retrieval has been implemented. Overall, this study suggests the possibility of acquiring statistically significant static packing structures within a reasonable time scale using high-intensity X-ray sources.

  12. Study of X-ray emission in aluminium z-pinches

    International Nuclear Information System (INIS)

    Rosch, R.

    1999-01-01

    Previous experiments, at 0.1. TX level, have shown that stability and x-ray emission of fast Z-pinches, could be strongly increased by imploding an aluminium vapor jet onto a very thin coaxial wire. We present here first results of an aluminium Z-pinch, using a similar liner, but at mega-ampere level. The pinch is driven by AMBIORIX high-power facility, a 2 TW, 0.5 Ω, 2 MA, 50 ns pulse-line generator. We study the effect of an aluminium wire and its diameter (20-50 μm) on the implosion dynamics, on x-ray yield on MHD stability of the column at stagnation. Analysis of A1 jet on A1 wire shots demonstrates that x-ray yield due to emission processes in the H- and He- like ionization stages (i.e. the K-shell) is significantly enhanced, relative to that of A1 jet only ones. The wire also leads to better symmetry of the implosion, and to better reproducibility of shots. X-ray signals exhibit two similar pulses, 10 ns in width, 15 ns spaced. To discern spectral origin of both pulses, experiments are realized with stainless steel wire (25 μm in diameter). Results show that liner and wire radial simultaneously and contribute to both pulses. Analysis of a typical A1 jet on A1 wire shot, using detailed collisional-radiative equilibrium (CRE) model is also given in this thesis. View o the pinch at stagnation as a cola-dense core surrounded by a hot-low density corona reproduces all features of the X-ray data. (author)

  13. X-ray absorption and emission studies of diamond nanoparticles

    International Nuclear Information System (INIS)

    Van Buuren, T.; Willey, T.; Raty, J.Y.; Galli, G.; Terminello, L.J.; Bostedt, C.

    2004-01-01

    Full text: A new family of carbon nanopaticles produced in detonations, are found to have a core of diamond with a coating fullerene- like carbon. X-ray diffraction and TEM show that the nanodiamond powder is crystalline and approximately 4 nm in diameter. These nano-sized diamonds do not display the characteristic property of other group IV nanoparticles: a strong widening of the energy gap between the conduction and valence bands owing to quantum-confinement effects. For nano-sized diamond with a size distribution of 4 nm, there is no shift of the band energies relative to bulk diamond. Although the C1s core exciton feature clearly observed in the K-edge absorption edge of bulk diamond is shifted and broadening due to increased overlap of the excited electron with the core holein the small particle. Also the depth of the second gap in the nanodiamond spectra is shallower than that of bulk diamond. A feature at lower energy in the X-ray absorption spectra that is not present in the bulk samples is consistent with a fullerene like surface reconstruction. By exposing the diamond nanoparticles to an Argon /Oxygen plasma then annealing in a UHV environment we have obtained a hydrogen free surface. The nanodiamonds processed in this manner show an increase fullerene type contribution in the carbon x-ray absorption pre-edge. High spatial resolution EELS measurements of the empty states of a single nanodiamond particle acquired with a ld emission TEM also show the core of the particle is bulk diamond like where as the surface has a fullerene like structure. Standard density-functional calculations on clusters in which the diamond surface bonds are terminated with hydrogen atoms, show that the bandgap begins to increase above the bulk value only for clusters smaller than 1 nm. Surface hydrogen atoms are found to be about as close as they do in molecular hydrogen and can escape as H 2 , forcing the respective carbon atoms to rearrange. A series of such rearrangements can

  14. Plasma Emission Profile Recreation using Soft X-Ray Tomography

    Science.gov (United States)

    Page, J. W.; Mauel, M. E.; Levesque, J. P.

    2015-11-01

    With sufficient views from multiple diode arrays, soft X-ray tomography is an invaluable plasma diagnostic because it is a non-perturbing method to reconstruct the emission within the interior of the plasma. In preparation for the installation of new SXR arrays in HBT-EP, we compute high-resolution tomographic reconstructions of discharges having kink-like structures that rotate nearly rigidly. By assuming a uniform angular mapping from the kink mode rotation, Δϕ ~ ωΔ t, a temporal sequence from a single 16-diode fan array represents as many as 16 x 100 independent views. We follow the procedure described by Wang and Granetz and use Bessel basis functions to take the inverse Radon transform. This transform is fit to our data using a least-squares method to estimate the internal SXR emissivity as a sum of polar functions. By varying different parameters of the transformation, we optimize the quality of our recreation of the emission profile and quantify how the reconstruction changes with the azimuthal order of the transform. Supported by U.S. DOE Grant DE-FG02-86ER53222.

  15. Working gas effects on the X-ray emission of a plasma focus device

    Energy Technology Data Exchange (ETDEWEB)

    Cengher, M; Presura, R; Zoita, V [Inst. of Physics and Technology of Radiation Devices, Bucharest (Romania)

    1997-12-31

    Experiments on the plasma focus device IPF-2/20 operating with argon, neon and mixtures of argon with deuterium were performed and some X-ray emission parameters measured. The time evolution of the X-ray emission and dependence of the X-ray yield on the working gas composition was analyzed. The softer X radiation was measured with time resolution in the energy bands from 4 to 40 keV, and the hard X-rays for energies above 200 keV. In deuterium-argon mixtures the soft X-ray yield increases both with pressure (for the same ratio of argon) and with the quantity of argon added to deuterium at the same total pressure. For argon or neon the hard X-ray yield is lower than for deuterium-heavy gas mixtures. The softer X-ray yield decreases with pressure both for neon and for argon. (author). 4 figs., 5 refs.

  16. Variability of X-ray emission from OB stars

    International Nuclear Information System (INIS)

    Collura, A.; Sciortino, S.; Serio, S.; Vaiana, G. S.; Harnden, F.R. JR.; Osservatorio Astronomico, Palermo, Italy; Harvard-Smithsonian Center for Astrophysics, Cambridge, MA)

    1989-01-01

    The variability in soft X-ray emission of 12 OB stars is studied. Two different methods of analysis, one more suitable for detecting short-term variations, the other aimed at detecting long time-scale variations, are applied to all stars in the sample. The long-term variability analysis shows that Cyg-OB2 8A Zeta Pup and Delta Ori exhibit significant count rate variations between different data sections. Similar variations are marginally detected in 15 Mon; the count rate variations for the other eight stars are consistent with statistical fluctuations. The light curve of Cyg-OB2 8A suggests the existence of two different emission levels. The short-term variability analysis detects marginal variability in Tau Sco with an effective amplitude of about 30 percent and a time scale of about 50 s. The upper limits to the effective short-term variability amplitude for all other sample stars are in the 10-30 percent range. 30 refs

  17. SphinX MEASUREMENTS OF THE 2009 SOLAR MINIMUM X-RAY EMISSION

    OpenAIRE

    Sylwester, J.; Kowalinski, M.; Gburek, S.; Siarkowski, M.; Kuzin, S.; Farnik, F.; Reale, F.; Phillips, K. J. H.; Bakala, J.; Gryciuk, M.; Podgorski, P.; Sylwester, B.

    2012-01-01

    The SphinX X-ray spectrophotometer on the CORONAS-PHOTON spacecraft measured soft X-ray emission in the 1-15 keV energy range during the deep solar minimum of 2009 with a sensitivity much greater than GOES. Several intervals are identified when the X-ray flux was exceptionally low, and the flux and solar X-ray luminosity are estimated. Spectral fits to the emission at these times give temperatures of 1.7-1.9 MK and emission measures between 4 x 10^47 cm^-3 and 1.1 x 10^48 cm^-3. Comparing Sph...

  18. X-ray emission from National Ignition Facility indirect drive targets

    International Nuclear Information System (INIS)

    Anderson, A.T.; Managan, R.A.; Tobin, M.T.; Peterson, P.F.

    1996-01-01

    We have performed a series of 1-D numerical simulations of the x-ray emission from National Ignition Facility (NIF) targets. Results are presented in terms of total x-ray energy, pulse length, and spectrum. Scaling of x-ray emissions is presented for variations in both target yield and hohlraum thickness. Experiments conducted on the Nova facility provide some validation of the computational tools and methods

  19. Luminosity dependence in the ratio of X-ray to infrared emission of QSOs

    International Nuclear Information System (INIS)

    Worrall, D.M.

    1987-01-01

    The correlation of X-ray and near-infrared luminosity is studied for a sample of radio-quiet QSOs. The X-ray to infrared ratio is found to decrease as the infrared luminosity increases. No preference is found between the correlations of X-ray luminosity with optical or infrared luminosity. This implies that optical and infrared emission are equally good predictors of X-ray emission. Source models which directly link infrared and X-ray emission are discussed, and a preference is found for a specific synchrotron self-Compton model. This model predicts the correct luminosity dependence of the X-ray to infrared ratio if certain conditions apply. 55 references

  20. Charge Exchange of Ne^9+ for X-ray Emission

    Science.gov (United States)

    Lyons, David

    2016-01-01

    Using the molecular-orbital close-coupling (MOCC) method, single electron capture (SEC) cross sections were computed for Ne^9+ colliding with H.Potential energies and nonadiabatic couplings were calculated and used to obtain the MOCC cross sections which are final-quantum-state-resolved including a separation of singlet and triplet states. Atomic-orbital close-coupling, classical trajectory Monte Carlo, and multichannel Landau-Zener (MCLZ) calculations are also performed. Cross sections for more complicated targets including He, H2, N2, H2O, CO, and CO2, were obtained with the MCLZ method. The SEC results are compared with experimental and other theoretical data, where available. The SEC cross sections are being used in cascade models to predict X-ray emission spectra relevant to solar systemand astrophysical environments.D. Lyons, R. S. Cumbee, P. D. Mullen, P. C. Stancil (UGA), D. R. Schultz (UNT), P. Liebermann (Wuppertal Univ.),R. Buenker (NCSU).This work was partially supported by NASA grant NNX09AC46G.

  1. Soft x-ray emission studies of several aluminum alloys

    International Nuclear Information System (INIS)

    Tsang, K.L.; Zhang, C.H.; Callcott, T.A.; Arakawa, E.T.; Ederer, D.L.; Biancaniello, F.; Curelaru, I.

    1986-01-01

    During the first few months of operation of our soft x-ray spectrometer at the NSLS, we have measured the L emission spectrum for three classes of aluminum alloys: dilute aluminum-magnesium alloys to extend the Al-Mg system to the impurity limit; a 50-50 alloy of aluminum-lithium to characterize the band structure of bulk samples of this potential battery electrolite; and the icosahedral and normal Al-Mn alloys to see if the two phases had measurably different density of states which have been predicted. All spectra shown are produced when core holes generated by energetic electrons or photons are filled by radiative transitions from conduction band states. Dipole selection rules govern the transitions. Thus, K spectra provide a measure of the p-symmetic partial density of states (DOS) near the atom. Similarly, L spectra produced by transitions to p-core holes map the s and d symmetric DOS in the vicinity of the atom with the core hole

  2. Soft x-ray emission studies of several aluminum alloys

    Energy Technology Data Exchange (ETDEWEB)

    Tsang, K.L.; Zhang, C.H.; Callcott, T.A.; Arakawa, E.T.; Ederer, D.L.; Biancaniello, F.; Curelaru, I.

    1986-09-23

    During the first few months of operation of our soft x-ray spectrometer at the NSLS, we have measured the L emission spectrum for three classes of aluminum alloys: dilute aluminum-magnesium alloys to extend the Al-Mg system to the impurity limit; a 50-50 alloy of aluminum-lithium to characterize the band structure of bulk samples of this potential battery electrolite; and the icosahedral and normal Al-Mn alloys to see if the two phases had measurably different density of states which have been predicted. All spectra shown are produced when core holes generated by energetic electrons or photons are filled by radiative transitions from conduction band states. Dipole selection rules govern the transitions. Thus, K spectra provide a measure of the p-symmetic partial density of states (DOS) near the atom. Similarly, L spectra produced by transitions to p-core holes map the s and d symmetric DOS in the vicinity of the atom with the core hole.

  3. PIXE (proton induced X-ray emission) analysis of caatinger

    International Nuclear Information System (INIS)

    Nakanishi, T.M.; Futatsugawa, Shoji; Sera, Kouichiro.

    1995-01-01

    Caatinger (Mimosa acutistipula Benth), which has been a popular wood among the people in north east part of Brazil, was analyzed using PIXE (proton induced X-ray emission). The wood sample was divided into three parts, center, inner and outer side of the wood. Using the wood slice of each part, Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, Mn, Fe, Cu, Zn, As, Se, Br, Rb, Sr, Y, Ru and Pb were detected. When the wood slices were decomposed with nitric acid, Co and Ni were able to be determined. Two samples, non-destructive and chemically treated sample, of heartwood and sapwood showed the similar concentration of the elements. There was a discrete change of the accumulated elements between heartwood and sapwood. Most of the elements detected tended to be concentrated at sapwood, whereas Ca, Cu and Sr were concentrated at heartwood. At center part, especially, Na, Mg, Fe and Sr were accumulated. Since most of the heartwood and sapwood is dead, discrete change of the element concentration suggests some element movement across the annual ring at heartwood formation. (author)

  4. Soft X-ray Emission from Large-Scale Galactic Outflows in Seyfert Galaxies

    Science.gov (United States)

    Colbert, E. J. M.; Baum, S.; O'Dea, C.; Veilleux, S.

    1998-01-01

    Kiloparsec-scale soft X-ray nebulae extend along the galaxy minor axes in several Seyfert galaxies, including NGC 2992, NGC 4388 and NGC 5506. In these three galaxies, the extended X-ray emission observed in ROSAT HRI images has 0.2-2.4 keV X-ray luminosities of 0.4-3.5 x 10(40) erg s(-1) . The X-ray nebulae are roughly co-spatial with the large-scale radio emission, suggesting that both are produced by large-scale galactic outflows. Assuming pressure balance between the radio and X-ray plasmas, the X-ray filling factor is >~ 10(4) times as large as the radio plasma filling factor, suggesting that large-scale outflows in Seyfert galaxies are predominantly winds of thermal X-ray emitting gas. We favor an interpretation in which large-scale outflows originate as AGN-driven jets that entrain and heat gas on kpc scales as they make their way out of the galaxy. AGN- and starburst-driven winds are also possible explanations if the winds are oriented along the rotation axis of the galaxy disk. Since large-scale outflows are present in at least 50 percent of Seyfert galaxies, the soft X-ray emission from the outflowing gas may, in many cases, explain the ``soft excess" X-ray feature observed below 2 keV in X-ray spectra of many Seyfert 2 galaxies.

  5. Spectral analysis of K-shell X-ray emission of magnesium plasma

    Indian Academy of Sciences (India)

    2014-02-06

    Feb 6, 2014 ... Spectral analysis of K-shell X-ray emission of magnesium plasma, produced by laser pulses of 45 fs duration, focussed up to an intensity of ∼1018 W cm-2, is carried out. The plasma conditions prevalent during the emission of X-ray spectrum were identified by comparing the experimental spectra with the ...

  6. Trends in grazing emission x-ray analysis techniques

    International Nuclear Information System (INIS)

    Grieken, R. van; Tsuji, K.; Injuk, J.

    2000-01-01

    In grazing-emission x-ray fluorescence (GEXRF) spectrometry, XRF is made surface-sensitive, not by grazing incidence of the exciting radiation as in total reflection XRF (TXRF), but by detecting only that part of fluorescence radiation that is emitted at grazing angles above a polished sample carrier or above a flat wafer. In case of GEXRF, and contrary to TXRF, wavelength-dispersive (WD) detection can be used. Applications are, in principle, similar to those of (variable angle) TXRF. At the laboratory scale, only prototype instruments are available, and the GEXRF unit can be an accessory to a commercial WD-XRF instrument. The detection limits of GEXRF are in the higher pg range, corresponding to a concentration of between 0.4-3 μg/l, if a sample volume of 100 μl is examined. Because of the WD detection, GEXRF also lends itself for the analysis of low-Z elements, from Z > 5; this is an advantage over conventional TXRF (but similar to TXRF using a thin-window energy-dispersive detector). Since the GEXRF prototype is a sequential rather than a simultaneous instrument, the analysis time is long when many elements have to be determined. Moreover, because the soft characteristic radiation is more strongly absorbed in its longer path through the matrix than in TXRF, the linear response for trace analysis using GEXRF is limited; this was proven by calculating the fluorescence intensities as a function of layer thickness and composition. The specimens are very limited in thickness. The sample preparation procedure for liquid or other samples to be analyzed with the GEXRF unit is thus very problematic. Results for water samples, bio-materials and pigment and aerosol samples have indeed shown that the quantitative nature of GEXRF for trace analysis is poor. The most promising features of GEXRF are in the field of surface and thin-layer analysis. Trace contaminations on silicon wafers can be determined and depth profiling can characterize stratified near-surface layers. But

  7. A ROTSE-I/ROSAT Survey of X-ray Emission from Contact Binary Stars

    Science.gov (United States)

    Geske, M.; McKay, T.

    2005-05-01

    Using public data from the ROSAT All Sky Survey (RASS) and the ROTSE-I Sky Patrols, the incidence of strong x-ray emissions from contact binary systems was examined. The RASS data was matched to an expanded catalog of contact binary systems from the ROTSE-I data, using a 35 arc second radius. X-ray luminosities for matching objects were then determined. This information was then used to evaluate the total x-ray emissions from all such objects, in order to determine their contribution to the galactic x-ray background.

  8. Space- and time-resolved diagnostics of soft x-ray emission from laser plasmas

    International Nuclear Information System (INIS)

    Richardson, M.C.; Jaanimagi, P.A.; Chen, H.

    1988-01-01

    The analysis of soft x-ray emission from plasmas created by intense short-wavelength laser radiation can provide much useful information on the density, temperature and ionization distribution of the plasma. Until recently, limitations of sensitivity and the availability of suitable x-ray optical elements have restricted studies of soft x-ray emission from laser plasmas. In this paper, the authors describe novel instrumentation which provides high sensitivity in the soft x-ray spectrum with spatial and temporal resolution in the micron and picosecond ranges respectively. These systems exploit advances made in soft x-ray optic and electro-optic technology. Their application in current studies of laser fusion, x-ray lasers, and high density atomic physics are discussed

  9. Weak Hard X-Ray Emission from Broad Absorption Line Quasars: Evidence for Intrinsic X-Ray Weakness

    DEFF Research Database (Denmark)

    Luo, B.; Brandt, W. N.; Alexander, D. M.

    2014-01-01

    We report NuSTAR observations of a sample of six X-ray weak broad absorption line (BAL) quasars. These targets, at z = 0.148-1.223, are among the optically brightest and most luminous BAL quasars known at z 330 times weaker than...... expected for typical quasars. Our results from a pilot NuSTAR study of two low-redshift BAL quasars, a Chandra stacking analysis of a sample of high-redshift BAL quasars, and a NuSTAR spectral analysis of the local BAL quasar Mrk 231 have already suggested the existence of intrinsically X-ray weak BAL...... quasars, i.e., quasars not emitting X-rays at the level expected from their optical/UV emission. The aim of the current program is to extend the search for such extraordinary objects. Three of the six new targets are weakly detected by NuSTAR with ≲ 45 counts in the 3-24 keV band, and the other three...

  10. INTEGRAL hard X-ray spectra of the cosmic X-ray background and Galactic ridge emission

    Science.gov (United States)

    Türler, M.; Chernyakova, M.; Courvoisier, T. J.-L.; Lubiński, P.; Neronov, A.; Produit, N.; Walter, R.

    2010-03-01

    Aims: We derive the spectra of the cosmic X-ray background (CXB) and of the Galactic ridge X-ray emission (GRXE) in the ~20-200 keV range from the data of the IBIS instrument aboard the INTEGRAL satellite obtained during the four dedicated Earth-occultation observations in early 2006. Methods: We analyze the modulation of the IBIS/ISGRI detector counts induced by the passage of the Earth through the field of view of the instrument. Unlike previous studies, we do not fix the spectral shape of the various contributions, but model instead their spatial distribution and derive for each of them the expected modulation of the detector counts. The spectra of the diffuse emission components are obtained by fitting the normalizations of the model lightcurves to the observed modulation in different energy bins. Because of degeneracy, we guide the fits with a realistic choice of the input parameters and a constraint for spectral smoothness. Results: The obtained CXB spectrum is consistent with the historic HEAO-1 results and falls slightly below the spectrum derived with Swift/BAT. A 10% higher normalization of the CXB cannot be completely excluded, but it would imply an unrealistically high albedo of the Earth. The derived spectrum of the GRXE confirms the presence of a minimum around 80 keV with improved statistics and yields an estimate of ~0.6 M⊙ for the average mass of white dwarfs in the Galaxy. The analysis also provides updated normalizations for the spectra of the Earth's albedo and the cosmic-ray induced atmospheric emission. Conclusions: This study demonstrates the potential of INTEGRAL Earth-occultation observations to derive the hard X-ray spectra of three fundamental components: the CXB, the GRXE and the Earth emission. Further observations would be extremely valuable to confirm our results with improved statistics.

  11. X-RAY EMISSION FROM MAGNETIC MASSIVE STARS

    International Nuclear Information System (INIS)

    Nazé, Yaël; Petit, Véronique; Rinbrand, Melanie; Owocki, Stan; Cohen, David; Ud-Doula, Asif; Wade, Gregg A.

    2014-01-01

    Magnetically confined winds of early-type stars are expected to be sources of bright and hard X-rays. To clarify the systematics of the observed X-ray properties, we have analyzed a large series of Chandra and XMM-Newton observations, corresponding to all available exposures of known massive magnetic stars (over 100 exposures covering ∼60% of stars compiled in the catalog of Petit et al.). We show that the X-ray luminosity is strongly correlated with the stellar wind mass-loss rate, with a power-law form that is slightly steeper than linear for the majority of the less luminous, lower- M-dot B stars and flattens for the more luminous, higher- M-dot O stars. As the winds are radiatively driven, these scalings can be equivalently written as relations with the bolometric luminosity. The observed X-ray luminosities, and their trend with mass-loss rates, are well reproduced by new MHD models, although a few overluminous stars (mostly rapidly rotating objects) exist. No relation is found between other X-ray properties (plasma temperature, absorption) and stellar or magnetic parameters, contrary to expectations (e.g., higher temperature for stronger mass-loss rate). This suggests that the main driver for the plasma properties is different from the main determinant of the X-ray luminosity. Finally, variations of the X-ray hardnesses and luminosities, in phase with the stellar rotation period, are detected for some objects and they suggest that some temperature stratification exists in massive stars' magnetospheres

  12. Elemental investigation of talcum baby powder by X-Ray florescence and fast neutron activation Techniques

    International Nuclear Information System (INIS)

    Hassan, M. F.; Abd El Wahab, M.; Nada, A.

    2008-01-01

    Different samples of Egyptian and Hungarian talcum powders were studied, using X-ray florescence (XRF) and Fast Neutron Activation Analysis (FNAA) techniques to ensure the safety of its use. The K (X-rays) and the gamma-rays were measured, using Si(Li) and high-purity germanium (HPGe) spectrometers to detect and determine qualitatively and quantitatively the constituents of the studied samples. The concentrations of the elements (Mg, Si, Al, Fe, Zn, and Ba) were measured and their presence was confirmed by X-ray, lifetime and/or XRF measurements. One of these samples was also studied, using the Environmental Scanning Electron Microscope (ESEM)

  13. A Fast Detection Algorithm for the X-Ray Pulsar Signal

    Directory of Open Access Journals (Sweden)

    Hao Liang

    2017-01-01

    Full Text Available The detection of the X-ray pulsar signal is important for the autonomous navigation system using X-ray pulsars. In the condition of short observation time and limited number of photons for detection, the noise does not obey the Gaussian distribution. This fact has been little considered extant. In this paper, the model of the X-ray pulsar signal is rebuilt as the nonhomogeneous Poisson distribution and, in the condition of a fixed false alarm rate, a fast detection algorithm based on maximizing the detection probability is proposed. Simulation results show the effectiveness of the proposed detection algorithm.

  14. Chandra X-ray Observations of Jovian Low-latitude Emissions: Morphological, Temporal, and Spectral Characteristics

    Science.gov (United States)

    Bhardwaj, Anil; Elsner, Ronald F.; Gladstone, G. Randall; Cravens, Thomas E.; Waiate J. Hunter, Jr.; Branduardi-Raymont, Graziella; Ford, Peter

    2004-01-01

    Chandra observed X-rays from Jupiter during 24-26 February 2003 for about 40 hours with the ACIS-S and HRC-I instruments. The analysis of Jovian low-latitude "disk" Xray emissions are presented and compared with the high-latitude "auroral" emissions. We report the first Chandra ACIS-S measured X-ray spectrum (0.3-2 keV) of Jupiter's low-latitude disk The disk X-ray emission is harder and extends to higher energies than the auroral spectrum. The temporal variation in the Jovian disk X-rays is on an average consistent with those in the solar X-rays observed by GOES, and TIMED/SSE. Contrary to the auroral X-rays, the disk emissions are uniformly distributed over Jupiter; no indication of longitudinal dependence or correlation with surface magneh field strength is visible. Also, unlike the approx. 40 +/- 20 min periodic oscillations seen in the auroral X-ray emissions, the disk emissions do not show any periodic oscillations. The disk spectrum seems to be consistent with resonant and fluorescent scattering of solar X-rays by the Jovian upper atmosphere. Jupiter's disk is found to be about 50% dimmer in soft X-rays in February 2003 compared that in December 2000, which is consistent with the decrease in solar activity. No evidence of lightning-induced X-rays is seen in the Chandra X-ray data. The Jovian disk spectra observed with Chandra-ACIS is stronger than that observed with XMM-Newton two months later during April 28-29, 2003. The XMM-Newton Xray image of Jupiter shows evidence of limb darkening on the anti-sunward side as seen from Earth, as well as an asymmetry with respect to the subsolar point: suggesting a solar driven process.

  15. X-ray emission from stainless steel foils irradiated by femtosecond petawatt laser pulses

    Science.gov (United States)

    Alkhimova, M. A.; Faenov, A. Ya; Pikuz, T. A.; Skobelev, I. Yu; Pikuz, S. A.; Nishiuchi, M.; Sakaki, H.; Pirozhkov, A. S.; Sagisaka, S.; Dover, N. P.; Kondo, Ko; Ogura, K.; Fukuda, Y.; Kiriyama, H.; Esirkepov, T.; Bulanov, S. V.; Andreev, A.; Kando, M.; Zhidkov, A.; Nishitani, K.; Miyahara, T.; Watanabe, Y.; Kodama, R.; Kondo, K.

    2018-01-01

    We report about nonlinear growth of x-ray emission intensity emitted from plasma generated by femtosecond petawatt laser pulses irradiating stainless steel foils. X-ray emission intensity increases as ˜ I 4.5 with laser intensity I on a target. High spectrally resolved x-ray emission from front and rear surfaces of 5 μm thickness stainless steel targets were obtained at the wavelength range 1.7-2.1 Å, for the first time in experiments at femtosecond petawatt laser facility J-KAREN-P. Total intensity of front x-ray spectra three times dominates to rear side spectra for maximum laser intensity I ≈ 3.2×1021 W/cm2. Growth of x-ray emission is mostly determined by contribution of bremsstrahlung radiation that allowed estimating bulk electron plasma temperature for various magnitude of laser intensity on target.

  16. Supergiant Fast X-ray Transients with Swift: spectroscopic and temporal properties

    OpenAIRE

    Romano, P.; Mangano, V.; Ducci, L.; Esposito, P.; Farinelli, R.; Ceccobello, C.; Vercellone, S.; Burrows, D. N.; Kennea, J. A.; Krimm, H. A.; Gehrels, N.

    2012-01-01

    Supergiant fast X-ray transients (SFXTs) are a class of high-mass X-ray binaries with possible counterparts in the high energy gamma rays. The Swift SFXT Project has conducted a systematic investigation of the properties of SFTXs on timescales ranging from minutes to years and in several intensity states (from bright flares, to intermediate intensity states, and down to almost quiescence). We also performed broad-band spectroscopy of outbursts, and intensity-selected spectroscopy outside of o...

  17. Development of fast parallel multi-technique scanning X-ray imaging at Synchrotron Soleil

    Science.gov (United States)

    Medjoubi, K.; Leclercq, N.; Langlois, F.; Buteau, A.; Lé, S.; Poirier, S.; Mercère, P.; Kewish, C. M.; Somogyi, A.

    2013-10-01

    A fast multimodal scanning X-ray imaging scheme is prototyped at Soleil Synchrotron. It permits the simultaneous acquisition of complementary information on the sample structure, composition and chemistry by measuring transmission, differential phase contrast, small-angle scattering, and X-ray fluorescence by dedicated detectors with ms dwell time per pixel. The results of the proof of principle experiments are presented in this paper.

  18. Supergiant fast X-ray transients with Swift: Spectroscopic and temporal properties

    Science.gov (United States)

    Romano, P.; Mangano, V.; Ducci, L.; Esposito, P.; Farinelli, R.; Ceccobello, C.; Vercellone, S.; Burrows, D. N.; Kennea, J. A.; Krimm, H. A.; Gehrels, N.

    2012-12-01

    Supergiant fast X-ray transients (SFXTs) are a class of high-mass X-ray binaries with possible counterparts in the high energy gamma rays. The Swift SFXT Project1 has conducted a systematic investigation of the properties of SFTXs on timescales ranging from minutes to years and in several intensity states (from bright flares, to intermediate intensity states, and down to almost quiescence). We also performed broad-band spectroscopy of outbursts, and intensity-selected spectroscopy outside of outbursts. We demonstrated that while the brightest phase of the outburst only lasts a few hours, further activity is observed at lower fluxes for a remarkably longer time, up to weeks. Furthermore, we assessed the fraction of the time these sources spend in each phase, and their duty cycle of inactivity. We present the most recent results from our investigation. The spectroscopic and, most importantly, timing properties of SFXTs we have uncovered with Swift will serve as a guide in search for the high energy emission from these enigmatic objects.

  19. DISCOVERY OF X-RAY EMISSION FROM THE GALACTIC SUPERNOVA REMNANT G32.8-0.1 WITH SUZAKU

    Energy Technology Data Exchange (ETDEWEB)

    Bamba, Aya; Sawada, Makoto [Department of Physics and Mathematics, Aoyama Gakuin University 5-10-1 Fuchinobe Chuo-ku, Sagamihara, Kanagawa 252-5258 (Japan); Terada, Yukikatsu [Department of Physics, Science, Saitama University, Sakura, Saitama 338-8570 (Japan); Hewitt, John; Petre, Robert; Angelini, Lorella [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Safi-Harb, Samar [Department of Physics and Astronomy, University of Manitoba, Winnipeg MB R3T 2N2 (Canada); Zhou, Ping [Department of Astronomy, Nanjing University, Nanjing 210093 (China); Bocchino, Fabrizio [INAF—Osservatorio Astronomico di Palermo, Piazza del Parlamento 1, I-90134, Palermo (Italy)

    2016-02-10

    We present the first dedicated X-ray study of the supernova remnant (SNR) G32.8−0.1 (Kes 78) with Suzaku. X-ray emission from the whole SNR shell has been detected for the first time. The X-ray morphology is well correlated with the emission from the radio shell, while anti-correlated with the molecular cloud found in the SNR field. The X-ray spectrum shows not only conventional low-temperature (kT ∼ 0.6 keV) thermal emission in a non-equilibrium ionization state, but also a very high-temperature (kT ∼ 3.4 keV) component with a very low ionization timescale (∼2.7 × 10{sup 9} cm{sup −3} s), or a hard nonthermal component with a photon index Γ ∼ 2.3. The average density of the low-temperature plasma is rather low, of the order of 10{sup −3}–10{sup −2} cm{sup −3}, implying that this SNR is expanding into a low-density cavity. We discuss the X-ray emission of the SNR, also detected in TeV with H.E.S.S., together with multi-wavelength studies of the remnant and other gamma-ray emitting SNRs, such as W28 and RCW 86. Analysis of a time-variable source, 2XMM J185114.3−000004, found in the northern part of the SNR, is also reported for the first time. Rapid time variability and a heavily absorbed hard-X-ray spectrum suggest that this source could be a new supergiant fast X-ray transient.

  20. Discovery of X-Ray Emission from the Galactic Supernova Remnant G32.8-0.1 with Suzaku

    Science.gov (United States)

    Bamba, Aya; Terada, Yukikatsu; Hewitt, John; Petre, Robert; Angelini, Lorella; Safi-Harb, Samar; Zhou, Ping; Bocchino, Fabrizio; Sawada, Makoto

    2016-01-01

    We present the first dedicated X-ray study of the supernova remnant (SNR) G32.8-0.1 (Kes 78) with Suzaku. X-ray emission from the whole SNR shell has been detected for the first time. The X-ray morphology is well correlated with the emission from the radio shell, while anti-correlated with the molecular cloud found in the SNR field. The X-ray spectrum shows not only conventional low-temperature (kT approximately 0.6 kiloelectronvolts) thermal emission in a nonequilibrium ionization state, but also a very high-temperature (approximately 3.4 kiloelectronvolts) component with a very low ionization timescale (approximately 2.7 times 10 (sup 9) per cubic centimeter per second), or a hard nonthermal component with a photon index Gamma approximately equal to 2.3. The average density of the low-temperature plasma is rather low, of the order of 10 (sup -3) - 10 (sup -2) per cubic centimeter, implying that this SNR is expanding into a low-density cavity. We discuss the X-ray emission of the SNR, also detected in teraelectronvolts with H.E.S.S. (High Energy Stereoscopic System), together with multi-wavelength studies of the remnant and other gamma-ray emitting SNRs, such as W28 and RCW 86. Analysis of a time-variable source, 2XMM J185114.3-000004, found in the northern part of the SNR, is also reported for the first time. Rapid time variability and a heavily absorbed hard-X-ray spectrum suggest that this source could be a new supergiant fast X-ray transient.

  1. Resonant soft X-ray emission spectroscopy of liquids

    International Nuclear Information System (INIS)

    Guo, J.-H.; Augustsson, A.; Englund, C.-J.; Nordgren, J.

    2004-01-01

    We present now a possible way to carry out soft-x-ray fluorescence spectroscopy of liquids. The liquid cell has a window to attain compatibility with UHV conditions of the spectrometer and beamline. The synchrotron radiation enters the liquid cell through a 100nm-thick silicon nitride window and the emitted x-rays exit through the same window. This allows in particular liquid solid interfaces to be studied. Such a liquid cell has been used to study the electronic structure of a variety of systems ranging from water solutions of inorganic salts and inertial drugs to nano materials and actinide compounds in their wet conditions

  2. The Soft X-ray real time fast trigger system

    International Nuclear Information System (INIS)

    Blackler, K.; Edwards, A.; Holm, J.

    1992-05-01

    Most current diagnostics are limited to recording data either at fixed times and data rates, or in response to certain predefined events - such as the injection of a pellet. The previous Soft X-Ray trigger system at Joint European Torus Joint Undertaking (JET)(A.W. Edwards et al., Rev Sci Instrum. 57(8), p2142, 1986) improved upon this by using Analogue Signal Processors to monitor the analogue data in real time and to provide 'triggers' to the data acquisition system in response to an event such as a sawtooth collapse. This system was however limited in the type of events that could be detected. It was also incapable of being rapidly re-configured. Advances in digital electronics caused a study to be undertaken to see if this situation could be improved. The system described below is the result of this study and has successfully run at JET since the summer of 1990, providing a greatly increased quality of data as well as recording some new phenomena such as the spontaneous snake. This note has been produced to describe the function and operation of the trigger system. (author)

  3. X-ray emission from open star clusters with Spectrum-Rontgen-Gamma

    DEFF Research Database (Denmark)

    Singh, K.P.; Ojha, D.K.; Schnopper, H.W.

    1998-01-01

    The study of X-ray emission from co-evolving populations of stars in open dusters is extremely important for understanding the dynamo activity among the stars. With this objective, we propose to observe a number of open clusters in the X-ray and UV bands using SPECTRUM-Rontgen-Gamma. The high...... throughput of SPECTRUM-Rontgen-Gamma will help detect main sequence stars like Sun in middle-aged and old clusters. We will study the relationships between various parameters - age, rotation, abundance, UBV colors, X-ray luminosity, coronal temperature etc. X-ray spectra of younger and brighter populations...

  4. Exploring the Hard and Soft X-ray Emission of Magnetic Cataclysmic Variables

    Science.gov (United States)

    de Martino, D.; Anzolin, G.; Bonnet-Bidaud, J.-M.; Falanga, M.; Matt, G.; Mouchet, M.; Mukai, K.; Masetti, N.

    2009-05-01

    A non-negligible fraction of galactic hard (>20 keV) X-ray sources were identified as CVs of the magnetic Intermediate Polar type in INTEGRAL, SWIFT and RXTE surveys, that suggests a still hidden but potentially important population of faint hard X-ray sources. Simbol-X has the unique potential to simultaneously characterize their variable and complex soft and hard X-ray emission thus allowing to understand their putative role in galactic populations of X-ray sources.

  5. DISCOVERY OF X-RAY EMISSION FROM YOUNG SUNS IN THE SMALL MAGELLANIC CLOUD

    International Nuclear Information System (INIS)

    Oskinova, L. M.; Hainich, R.; Sun, W.; Chen, Y.; Evans, C. J.; Hénault-Brunet, V.; Chu, Y.-H.; Gruendl, R. A.; Gallagher, J. S. III; Guerrero, M. A.; Güdel, M.; Silich, S.; Nazé, Y.; Reyes-Iturbide, J.

    2013-01-01

    We report the discovery of extended X-ray emission within the young star cluster NGC 602a in the Wing of the Small Magellanic Cloud (SMC) based on observations obtained with the Chandra X-Ray Observatory. X-ray emission is detected from the cluster core area with the highest stellar density and from a dusty ridge surrounding the H II region. We use a census of massive stars in the cluster to demonstrate that a cluster wind or wind-blown bubble is unlikely to provide a significant contribution to the X-ray emission detected from the central area of the cluster. We therefore suggest that X-ray emission at the cluster core originates from an ensemble of low- and solar-mass pre-main-sequence (PMS) stars, each of which would be too weak in X-rays to be detected individually. We attribute the X-ray emission from the dusty ridge to the embedded tight cluster of the newborn stars known in this area from infrared studies. Assuming that the levels of X-ray activity in young stars in the low-metallicity environment of NGC 602a are comparable to their Galactic counterparts, then the detected spatial distribution, spectral properties, and level of X-ray emission are largely consistent with those expected from low- and solar-mass PMS stars and young stellar objects (YSOs). This is the first discovery of X-ray emission attributable to PMS stars and YSOs in the SMC, which suggests that the accretion and dynamo processes in young, low-mass objects in the SMC resemble those in the Galaxy.

  6. A PILOT DEEP SURVEY FOR X-RAY EMISSION FROM fuvAGB STARS

    Energy Technology Data Exchange (ETDEWEB)

    Sahai, R. [Jet Propulsion Laboratory, MS 183-900, California Institute of Technology, Pasadena, CA 91109 (United States); Sanz-Forcada, J.; Sánchez Contreras, C. [Astrobiology Center (CSIC-INTA), ESAC campus, E-28691 Villanueva de la Canada, Madrid (Spain); Stute, M. [Institute for Astronomy and Astrophysics, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 10, D-72076, Tübingen (Germany)

    2015-09-01

    We report the results of a pilot survey for X-ray emission from a newly discovered class of AGB stars with far-ultraviolet excesses (fuvAGB stars) using XMM-Newton and Chandra. We detected X-ray emission in three of six fuvAGB stars observed—the X-ray fluxes are found to vary in a stochastic or quasi-periodic manner on roughly hour-long timescales, and simultaneous UV observations using the Optical Monitor on XMM for these sources show similar variations in the UV flux. These data, together with previous studies, show that X-ray emission is found only in fuvAGB stars. From modeling the spectra, we find that the observed X-ray luminosities are ∼(0.002–0.2) L{sub ⊙} and the X-ray-emitting plasma temperatures are ∼(35–160) × 10{sup 6} K. The high X-ray temperatures argue against the emission arising in stellar coronae, or directly in an accretion shock, unless it occurs on a WD companion. However, none of the detected objects is a known WD-symbiotic star, suggesting that if WD companions are present, they are relatively cool (<20,000 K). In addition, the high X-ray luminosities specifically argue against emission originating in the coronae of main-sequence companions. We discuss several models for the X-ray emission and its variability and find that the most likely scenario for the origin of the X-ray (and FUV) emission involves accretion activity around a companion star, with confinement by strong magnetic fields associated with the companion and/or an accretion disk around it.

  7. X-ray emission from supernova remnants with particular reference to the Cygnus Loop

    International Nuclear Information System (INIS)

    Gronenschild, E.H.B.M.

    1979-01-01

    Observational or theoretical results related to the study of supernova remnants (SNRs) are described. Some background information is given by reviewing the present status of our knowledge of supernovae and supernova remnants, both from theory and observations. Also the distribution of all known radio, optical, and X-ray SNRs in the Galaxy is shown and a comparison is made. The X-ray observations of the well-known X-ray SNR the Cygnus Loop are discussed in detail and the discovery of a new X-ray emitting SNR W44 is described. Other radio sources are investigated, and the observed X-ray emission of SNRs are analysed using thermal spectra like exponential or bremsstrahlung spectra. The X-ray line spectrum that emerges from SNRs is described in detail. (Auth.)

  8. X-ray absorption and X-ray emission spectroscopy theory and applications

    CERN Document Server

    Lamberti, Carlo

    2016-01-01

    During the last two decades, remarkable and often spectacular progress has been made in the methodological and instrumental aspects of x–ray absorption and emission spectroscopy. This progress includes considerable technological improvements in the design and production of detectors especially with the development and expansion of large-scale synchrotron reactors All this has resulted in improved analytical performance and new applications, as well as in the perspective of a dramatic enhancement in the potential of x–ray based analysis techniques for the near future. This comprehensive two-volume treatise features articles that explain the phenomena and describe examples of X–ray absorption and emission applications in several fields, including chemistry, biochemistry, catalysis, amorphous and liquid systems, synchrotron radiation, and surface phenomena. Contributors explain the underlying theory, how to set up X–ray absorption experiments, and how to analyze the details of the resulting spectra. X-R...

  9. X-Ray Emission of Cataclysmic Variables Observed by Integral

    Czech Academy of Sciences Publication Activity Database

    Gális, R.; Eckert, D.; Paltani, S.; Münz, F.; Kocka, Matúš

    2009-01-01

    Roč. 18, 3-4 (2009), s. 321-326 ISSN 1392-0049 Grant - others:ESA(XE) ESA- PECS project No. 98023; VEGA(SK) 2/0078/10 Institutional research plan: CEZ:AV0Z10030501 Keywords : binaries starss * cataclysmic * X-rays Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 1.032, year: 2009

  10. X-ray Emission Characteristics of Flares Associated with CMEs ...

    Indian Academy of Sciences (India)

    tics of solar flares and their relationship with the dynamics of CMEs have ... lation between X-ray peak intensity of the flares with linear speed as well ... shear angle (θ1, measured at the flare onset), the final shear angle (θ2, measured at the.

  11. Modeling Flare Hard X-ray Emission from Electrons in Contracting Magnetic Islands

    Science.gov (United States)

    Guidoni, Silvina E.; Allred, Joel C.; Alaoui, Meriem; Holman, Gordon D.; DeVore, C. Richard; Karpen, Judith T.

    2016-05-01

    The mechanism that accelerates particles to the energies required to produce the observed impulsive hard X-ray emission in solar flares is not well understood. It is generally accepted that this emission is produced by a non-thermal beam of electrons that collides with the ambient ions as the beam propagates from the top of a flare loop to its footpoints. Most current models that investigate this transport assume an injected beam with an initial energy spectrum inferred from observed hard X-ray spectra, usually a power law with a low-energy cutoff. In our previous work (Guidoni et al. 2016), we proposed an analytical method to estimate particle energy gain in contracting, large-scale, 2.5-dimensional magnetic islands, based on a kinetic model by Drake et al. (2010). We applied this method to sunward-moving islands formed high in the corona during fast reconnection in a simulated eruptive flare. The overarching purpose of the present work is to test this proposed acceleration model by estimating the hard X-ray flux resulting from its predicted accelerated-particle distribution functions. To do so, we have coupled our model to a unified computational framework that simulates the propagation of an injected beam as it deposits energy and momentum along its way (Allred et al. 2015). This framework includes the effects of radiative transfer and return currents, necessary to estimate flare emission that can be compared directly to observations. We will present preliminary results of the coupling between these models.

  12. Seven years with the Swift Supergiant Fast X-ray Transients project

    Science.gov (United States)

    Romano, P.

    2015-09-01

    Supergiant Fast X-ray Transients (SFXTs) are HMXBs with OB supergiant companions. I review the results of the Swift SFXT project, which since 2007 has been exploiting Swift's capabilities in a systematic study of SFXTs and supergiant X-ray binaries (SGXBs) by combining follow-ups of outbursts, when detailed broad-band spectroscopy is possible, with long-term monitoring campaigns, when the out-of-outburst fainter states can be observed. This strategy has led us to measure their duty cycles as a function of luminosity, to extract their differential luminosity distributions in the soft X-ray domain, and to compare, with unprecedented detail, the X-ray variability in these different classes of sources. I also discuss the ;seventh year crisis;, the challenges that the recent Swift observations are making to the prevailing models attempting to explain the SFXT behavior.

  13. X-ray emission reduction and photon dose lowering by energy loss of fast electrons induced by return current during the interaction of a short-pulse high-intensity laser on a metal solid target

    Science.gov (United States)

    Compant La Fontaine, A.

    2018-04-01

    During the interaction of a short-pulse high-intensity laser with the preplasma produced by the pulse's pedestal in front of a high-Z metal solid target, high-energy electrons are produced, which in turn create an X-ray source by interacting with the atoms of the converter target. The current brought by the hot electrons is almost completely neutralized by a return current j → driven by the background electrons of the conductive target, and the force exerted on the hot electrons by the electric field E → which induces Ohmic heating j → .E → , produced by the background electrons, reduces the energy of the hot electrons and thus lowers the X-ray emission and photon dose. This effect is analyzed here by means of a simple 1-D temperature model which contains the most significant terms of the relativistic Fokker-Planck equation with electron multiple scattering, and the energy equations of ions, hot, and cold electrons are then solved numerically. This Ohmic heating energy loss fraction τOh is introduced as a corrective term in an improved photon dose model. For instance, for a ps laser pulse with 10 μm spot size, the dose obtained with a tantalum target is reduced by less than about 10% to 40% by the Ohmic heating, depending upon the plasma scale length, target thickness, laser parameters, and in particular its spot size. The laser and plasma parameters may be optimized to limit the effect of Ohmic heating, for instance at a small plasma scale length or small laser spot size. Conversely, others regimes not suitable for dose production are identified. For instance, the resistive heating is enhanced in a foam target or at a long plasma scale length and high laser spot size and intensity, as the mean emission angle θ0 of the incident hot electron bunch given by the ponderomotive force is small; thus, the dose produced by a laser interacting in a gas jet may be inhibited under these circumstances. The resistive heating may also be maximized in order to reduce

  14. Hard X-ray Emission and Efficient Particle Acceleration by Supernova Remnants

    International Nuclear Information System (INIS)

    Vink, Jacco

    2009-01-01

    I discuss the non-thermal X-ray emission from young supernova remnants. Over the last decade it has become clear from both X-ray and γ-ray observations that young supernovae accelerate particles up to 100 TeV. In soft X-rays the accelerated >10 TeV electrons produce synchrotron radiation, coming from narrow filaments located at the shock fronts. The width of these filaments shows that the magnetic fields are relatively high, thus providing evidence for magnetic field amplification.The synchrotron radiation of several remnants is known to extend into the hard X-ray regime. In particular Cas A, has a spectrum that appears as a power law up to almost 100 TeV. This is very surprising, as a steepening is expected going from the soft to the hard X-ray band. The spectrum is likely a result of many superimposed individual spectra, each steepening at different energies. This implies considerable spatial variation in hard X-rays, an obvious target for Simbol-X. The variations will be important to infer local shock acceleration properties, but also magnetic field fluctuations may cause spatial and temporal variations.Finally, I draw the attention to super bubbles and supernovae as sources of cosmic rays. As such they may be sources of hard X-ray emission. In particular, supernovae exploding inside the dense red supergiants winds of their progenitors ares promising candidates for hard X-ray emission.

  15. Hard X-ray Emission and Efficient Particle Acceleration by Supernova Remnants

    Science.gov (United States)

    Vink, Jacco

    2009-05-01

    I discuss the non-thermal X-ray emission from young supernova remnants. Over the last decade it has become clear from both X-ray and γ-ray observations that young supernovae accelerate particles up to 100 TeV. In soft X-rays the accelerated >10 TeV electrons produce synchrotron radiation, coming from narrow filaments located at the shock fronts. The width of these filaments shows that the magnetic fields are relatively high, thus providing evidence for magnetic field amplification. The synchrotron radiation of several remnants is known to extend into the hard X-ray regime. In particular Cas A, has a spectrum that appears as a power law up to almost 100 TeV. This is very surprising, as a steepening is expected going from the soft to the hard X-ray band. The spectrum is likely a result of many superimposed individual spectra, each steepening at different energies. This implies considerable spatial variation in hard X-rays, an obvious target for Simbol-X. The variations will be important to infer local shock acceleration properties, but also magnetic field fluctuations may cause spatial and temporal variations. Finally, I draw the attention to super bubbles and supernovae as sources of cosmic rays. As such they may be sources of hard X-ray emission. In particular, supernovae exploding inside the dense red supergiants winds of their progenitors ares promising candidates for hard X-ray emission.

  16. News on the X-ray emission from hot subdwarf stars

    Directory of Open Access Journals (Sweden)

    Palombara Nicola La

    2017-12-01

    Full Text Available In latest years, the high sensitivity of the instruments on-board the XMM-Newton and Chandra satellites allowed us to explore the properties of the X-ray emission from hot subdwarf stars. The small but growing sample of X-ray detected hot subdwarfs includes binary systems, in which the X-ray emission is due to wind accretion onto a compact companion (white dwarf or neutron star, as well as isolated sdO stars, in which X-rays are probably due to shock instabilities in the wind. X-ray observations of these low-mass stars provide information which can be useful for our understanding of the weak winds of this type of stars and can lead to the discovery of particularly interesting binary systems. Here we report the most recent results we have recently obtained in this research area.

  17. Characterizing X-Ray and Radio Emission in the Black Hole X-Ray Binary V404 Cygni During Quiescence

    DEFF Research Database (Denmark)

    Rana, Vikram; Loh, Alan; Corbel, Stephane

    2016-01-01

    We present results from multi-wavelength simultaneous X-ray and radio observations of the black hole X-ray binary V404 Cyg in quiescence. Our coverage with NuSTAR provides the very first opportunity to study the X-ray spectrum of V404 Cyg at energies above 10 keV. The unabsorbed broadband (0...

  18. Soft x-ray emission from classical novae in outburst

    International Nuclear Information System (INIS)

    Starrfield, S.; Krautter, J.; MacDonald, J.

    1989-01-01

    Theoretical modeling of novae in outburst predicts that they should be active emitters of radiation at soft x-ray wavelengths twice during their outburst. The first time occurs very early in the outburst when only a very sensitive all sky survey will be able to detect them. This period lasts only a few hours for the very fastest novae. They again become bright in x-rays late in the outburst when the remnant object becomes very hot and is still luminous. Both simulations and observations show that novae can remain very hot for months to years. It is important to observe them at these late times because a measurement both of the flux and temperature can provide information about the mass of the white dwarf, the turn-off time scale, and the energy budget of the outburst. 8 refs., 2 figs

  19. Coaxial gun parameters and X-ray emission

    International Nuclear Information System (INIS)

    Soliman, H.M.; El-Aragi, G.M.; Saudy, A.H.; Masoud, M.M.

    1994-01-01

    The paper presents the results of investigation with 3 kJ coaxial plasma gun, which operated with argon gas at pressure 0.8 torr. The coaxial plasma gun parameters are investigated by pick up coils, double electric probe, and x-ray probe. The mean electron temperature and density of the ejected plasma are 25 eV and 10 15 cm -3 respectively. The maximum kinetic pressure of the ejected plasma in the expansion chamber appears after 10 μs from the start of the discharge current. The energetic electrons is detected by an x-ray probe which showed a single pulse of electrons with energy ≅ 3 Kev. (orig.)

  20. Nonlinear QED effects in X-ray emission of pulsars

    Energy Technology Data Exchange (ETDEWEB)

    Shakeri, Soroush [Department of Physics, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Haghighat, Mansour [Department of Physics, Shiraz University, Shiraz 71946-84795 (Iran, Islamic Republic of); Xue, She-Sheng, E-mail: Soroush.Shakeri@ph.iut.ac.ir, E-mail: m.haghighat@shirazu.ac.ir, E-mail: xue@icra.it [ICRANet, Piazzale della Repubblica 10, 65122, Pescara (Italy)

    2017-10-01

    In the presence of strong magnetic fields near pulsars, the QED vacuum becomes a birefringent medium due to nonlinear QED interactions. Here, we explore the impact of the effective photon-photon interaction on the polarization evolution of photons propagating through the magnetized QED vacuum of a pulsar. We solve the quantum Boltzmann equation within the framework of the Euler-Heisenberg Lagrangian to find the evolution of the Stokes parameters. We find that linearly polarized X-ray photons propagating outward in the magnetosphere of a rotating neutron star can acquire high values for the circular polarization parameter. Meanwhile, it is shown that the polarization characteristics of photons besides photon energy depend strongly on parameters of the pulsars such as magnetic field strength, inclination angle and rotational period. Our results are clear predictions of QED vacuum polarization effects in the near vicinity of magnetic stars which can be tested with the upcoming X-ray polarimetric observations.

  1. AGN X-Ray emission and black holes (Kelly+, 2008)

    DEFF Research Database (Denmark)

    Kelly, B. C.; Bechtold, J.; Trump, J. R.

    2009-01-01

    In this analysis we combine 169 RQQs from Kelly et al. (2007ApJ...665.1489K) with 149 RQQs from the main SDSS sample of Strateva et al. (2005, Cat. J/AJ/130/387) to create a sample of 318 RQQs. Out of these 318 sources, 276 (86.8%) are detected in the X-ray. (1 data file)....

  2. X-ray emission from clusters and groups of galaxies

    Science.gov (United States)

    Mushotzky, R.

    1998-01-01

    Recent major advances in x-ray imaging and spectroscopy of clusters have allowed the determination of their mass and mass profile out to approximately 1/2 the virial radius. In rich clusters, most of the baryonic mass is in the gas phase, and the ratio of mass in gas/stars varies by a factor of 2-4. The baryonic fractions vary by a factor of approximately 3 from cluster to cluster and almost always exceed 0.09 h50-[3/2] and thus are in fundamental conflict with the assumption of Omega = 1 and the results of big bang nucleosynthesis. The derived Fe abundances are 0.2-0.45 solar, and the abundances of O and Si for low redshift systems are 0.6-1.0 solar. This distribution is consistent with an origin in pure type II supernova. The amount of light and energy produced by these supernovae is very large, indicating their importance in influencing the formation of clusters and galaxies. The lack of evolution of Fe to a redshift of z approximately 0.4 argues for very early enrichment of the cluster gas. Groups show a wide range of abundances, 0.1-0.5 solar. The results of an x-ray survey indicate that the contribution of groups to the mass density of the universe is likely to be larger than 0.1 h50-2. Many of the very poor groups have large x-ray halos and are filled with small galaxies whose velocity dispersion is a good match to the x-ray temperatures.

  3. Alpha Particle Induced X-ray Emission in the Classroom

    International Nuclear Information System (INIS)

    Lopez, Jorge A.; Borunda, Mario F.; Morales, Jaime

    2003-01-01

    We report on an experimental demonstration in an introductory modern physics course to elucidate the X-ray line spectra, and how they arise from transitions of electrons to inner shells. We seek to determine the effect of limited use of an interactive component as a supplement to a traditional lecture, and how it would improve the student achievement. In this preliminary study the students were exposed to traditional lectures on X-ray production and Bohr's model, they then were given a homework on the abc of X-ray spectra, after which they were given a pre-test on the materials, followed by an in-class demonstration, and a final post-exam. The gain, as measured from pre- to post-exams appears to remark the differences in how students approached the subject before and after the use of the demonstration. This initial study shows the validity of in-class demonstrations as teaching tools and opens a wide new area of research in modern physics teaching

  4. A SEARCH FOR X-RAY EMISSION FROM COLLIDING MAGNETOSPHERES IN YOUNG ECCENTRIC STELLAR BINARIES

    Energy Technology Data Exchange (ETDEWEB)

    Getman, Konstantin V.; Broos, Patrick S. [Department of Astronomy and Astrophysics, 525 Davey Laboratory, Pennsylvania State University, University Park, PA 16802 (United States); Kóspál, Ágnes [Konkoly Observatory, Research Center for Astronomy and Earth Sciences, Hungarian Academy of Sciences, P.O. Box 67, 1525 Budapest (Hungary); Salter, Demerese M. [Department of Astronomy and Laboratory for Millimeter-Wave Astronomy, University of Maryland, College Park, MD 20742 (United States); Garmire, Gordon P. [Huntingdon Institute for X-ray Astronomy, LLC, 10677 Franks Road, Huntingdon, PA 16652 (United States)

    2016-12-01

    Among young binary stars whose magnetospheres are expected to collide, only two systems have been observed near periastron in the X-ray band: the low-mass DQ Tau and the older and more massive HD 152404. Both exhibit elevated levels of X-ray emission at periastron. Our goal is to determine whether colliding magnetospheres in young high-eccentricity binaries commonly produce elevated average levels of X-ray activity. This work is based on Chandra snapshots of multiple periastron and non-periastron passages in four nearby young eccentric binaries (Parenago 523, RX J1622.7-2325 Nw, UZ Tau E, and HD 152404). We find that for the merged sample of all four binaries the current X-ray data show an increasing average X-ray flux near periastron (at a ∼2.5-sigma level). Further comparison of these data with the X-ray properties of hundreds of young stars in the Orion Nebula Cluster, produced by the Chandra Orion Ultradeep Project (COUP), indicates that the X-ray emission from the merged sample of our binaries cannot be explained within the framework of the COUP-like X-ray activity. However, due to the inhomogeneities of the merged binary sample and the relatively low statistical significance of the detected flux increase, these findings are regarded as tentative only. More data are needed to prove that the flux increase is real and is related to the processes of colliding magnetospheres.

  5. Spectral analysis of K-shell X-ray emission of magnesium plasma ...

    Indian Academy of Sciences (India)

    2014-02-06

    Feb 6, 2014 ... the experimental spectra with the synthetic spectra generated using .... user to specify the time duration over which the ionic populations ... ied the dependence of X-ray emission spectrum as a function of laser intensity in the.

  6. The determination of light elements in heavy matrix using proton induced X-ray emission

    International Nuclear Information System (INIS)

    Levenets, V.V.; Omel'nik, A.P.; Shchur, A.A.; Chernov, A.E.; Usikov, N.P.; Zats, A.V.

    2007-01-01

    In this report the possibility of determination of light impurities in heavy matrixes is studied using proton induced X-Ray emission. The wide-band X-ray emission filter made from pyrolytic graphite was used in spectrometric scheme of experiment. The results of studying of filter features in energy range of X-ray emission from 4 to 12 keV were presented. The possibilities were examined of application of pyrolytic graphite filter to modify the X-rays spectrum for determination of iron, using characteristic emission of K-series, and hafnium, using L-series, in substances on base of zirconium (glasses, alloys etc.). It was shown, that the using of similar filter allows to reach the significant improving of metrological characteristics of analysis of mentioned impurities: the limits of detection of iron and hafnium were lowered single-order of magnitude. (authors)

  7. The Elusive Soft Emission from Hard X-ray Symbiotic System RT Cru

    Science.gov (United States)

    Karovska, Margarita

    2014-09-01

    RT Cru is a fascinating member of a new class of hard X-ray emitting symbiotic binaries showing X-ray emission extending to over 50keV. While its hard X-ray emission has been studied in detail, the soft component of the spectrum, including flares, remains elusive, since previous observations have focused on the high-energy regime. We propose Chandra HRC-S/LETG observations to determine the spatial, spectral, and temporal characteristics of the source of the soft X-ray emission with a goal to establish the origin of the soft component, and determine whether and how it is tied to the hard component. Determining the origin of the soft emission is a crucial piece of the puzzle to understanding the geometry, energetics, and the environment of WD accretion in this class of symbiotic systems.

  8. Laboratory simulation of charge exchange-produced X-ray emission from comets.

    Science.gov (United States)

    Beiersdorfer, P; Boyce, K R; Brown, G V; Chen, H; Kahn, S M; Kelley, R L; May, M; Olson, R E; Porter, F S; Stahle, C K; Tillotson, W A

    2003-06-06

    In laboratory experiments using the engineering spare microcalorimeter detector from the ASTRO-E satellite mission, we recorded the x-ray emission of highly charged ions of carbon, nitrogen, and oxygen, which simulates charge exchange reactions between heavy ions in the solar wind and neutral gases in cometary comae. The spectra are complex and do not readily match predictions. We developed a charge exchange emission model that successfully reproduces the soft x-ray spectrum of comet Linear C/1999 S4, observed with the Chandra X-ray Observatory.

  9. CHANDRA DETECTION OF X-RAY EMISSION FROM ULTRACOMPACT DWARF GALAXIES AND EXTENDED STAR CLUSTERS

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Meicun; Li, Zhiyuan, E-mail: lizy@nju.edu.cn [School of Astronomy and Space Science, Nanjing University, Nanjing 210046 (China)

    2016-03-10

    We have conducted a systematic study of X-ray emission from ultracompact dwarf (UCD) galaxies and extended star clusters (ESCs), based on archival Chandra observations. Among a sample of 511 UCDs and ESCs complied from the literature, 17 X-ray counterparts with 0.5–8 keV luminosities above ∼5 × 10{sup 36} erg s{sup −1} are identified, which are distributed in eight early-type host galaxies. To facilitate comparison, we also identify X-ray counterparts of 360 globular clusters (GCs) distributed in four of the eight galaxies. The X-ray properties of the UCDs and ESCs are found to be broadly similar to those of the GCs. The incidence rate of X-ray-detected UCDs and ESCs, 3.3% ± 0.8%, while lower than that of the X-ray-detected GCs (7.0% ± 0.4%), is substantially higher than expected from the field populations of external galaxies. A stacking analysis of the individually undetected UCDs/ESCs further reveals significant X-ray signals, which corresponds to an equivalent 0.5–8 keV luminosity of ∼4 × 10{sup 35} erg s{sup −1} per source. Taken together, these provide strong evidence that the X-ray emission from UCDs and ESCs is dominated by low-mass X-ray binaries having formed from stellar dynamical interactions, consistent with the stellar populations in these dense systems being predominantly old. For the most massive UCDs, there remains the possibility that a putative central massive black hole gives rise to the observed X-ray emission.

  10. CHANDRA DETECTION OF X-RAY EMISSION FROM ULTRACOMPACT DWARF GALAXIES AND EXTENDED STAR CLUSTERS

    International Nuclear Information System (INIS)

    Hou, Meicun; Li, Zhiyuan

    2016-01-01

    We have conducted a systematic study of X-ray emission from ultracompact dwarf (UCD) galaxies and extended star clusters (ESCs), based on archival Chandra observations. Among a sample of 511 UCDs and ESCs complied from the literature, 17 X-ray counterparts with 0.5–8 keV luminosities above ∼5 × 10 36 erg s −1 are identified, which are distributed in eight early-type host galaxies. To facilitate comparison, we also identify X-ray counterparts of 360 globular clusters (GCs) distributed in four of the eight galaxies. The X-ray properties of the UCDs and ESCs are found to be broadly similar to those of the GCs. The incidence rate of X-ray-detected UCDs and ESCs, 3.3% ± 0.8%, while lower than that of the X-ray-detected GCs (7.0% ± 0.4%), is substantially higher than expected from the field populations of external galaxies. A stacking analysis of the individually undetected UCDs/ESCs further reveals significant X-ray signals, which corresponds to an equivalent 0.5–8 keV luminosity of ∼4 × 10 35 erg s −1 per source. Taken together, these provide strong evidence that the X-ray emission from UCDs and ESCs is dominated by low-mass X-ray binaries having formed from stellar dynamical interactions, consistent with the stellar populations in these dense systems being predominantly old. For the most massive UCDs, there remains the possibility that a putative central massive black hole gives rise to the observed X-ray emission

  11. X-ray Imaging and preliminary studies of the X-ray self-emission from an innovative plasma-trap based on the Bernstein waves heating mechanism

    Science.gov (United States)

    Caliri, C.; Romano, F. P.; Mascali, D.; Gammino, S.; Musumarra, A.; Castro, G.; Celona, L.; Neri, L.; Altana, C.

    2013-10-01

    Electron Cyclotron Resonance Ion Sources (ECRIS) are based on ECR heated plasmas emitting high fluxes of X-rays. Here we illustrate a pilot study of the X-ray emission from a compact plasma-trap in which an off-resonance microwave-plasma interaction has been attempted, highlighting a possible Bernstein-Waves based heating mechanism. EBWs-heating is obtained via the inner plasma EM-to-ES wave conversion and enables to reach densities much larger than the cut-off ones. At LNS-INFN, an innovative diagnostic technique based on the design of a Pinhole Camera (PHC) coupled to a CCD device for X-ray Imaging of the plasma (XRI) has been developed, in order to integrate X-ray traditional diagnostics (XRS). The complementary use of electrostatic probes measurements and X-ray diagnostics enabled us to gain knowledge about the high energy electrons density and temperature and about the spatial structure of the source. The combination of the experimental data with appropriate modeling of the plasma-source allowed to estimate the X-ray emission intensity in different energy domains (ranging from EUV up to Hard X-rays). The use of ECRIS as X-ray source for multidisciplinary applications, is now a concrete perspective due to the intense fluxes produced by the new plasma heating mechanism.

  12. Modeling of X-ray emissions produced by stepping lightning leaders

    OpenAIRE

    Xu , Wei; Celestin , Sebastien; Pasko , Victor P.

    2014-01-01

    International audience; Intense and brief bursts of X-ray emissions have been measured during the stepping processof both natural cloud-to-ground (CG) and rocket-triggered lightning flashes. In this paper, we investigatetheoretically the energy spectra of X-rays produced by the bremsstrahlung emission of thermal runawayelectrons accelerated in the inhomogeneous electric field produced around lightning leader tips. The X-rayenergy spectrum depends on the physical properties of the associated l...

  13. X-ray emission as a potential hazard during ultrashort pulse laser material processing

    Science.gov (United States)

    Legall, Herbert; Schwanke, Christoph; Pentzien, Simone; Dittmar, Günter; Bonse, Jörn; Krüger, Jörg

    2018-06-01

    In laser machining with ultrashort laser pulses unwanted X-ray radiation in the keV range can be generated when a critical laser intensity is exceeded. Even if the emitted X-ray dose per pulse is low, high laser repetition rates can lead to an accumulation of X-ray doses beyond exposure safety limits. For 925 fs pulse duration at a center wavelength of 1030 nm, the X-ray emission was investigated up to an intensity of 2.6 × 1014 W/cm2. The experiments were performed in air with a thin disk laser at a repetition rate of 400 kHz. X-ray spectra and doses were measured for various planar target materials covering a wide range of the periodic table from aluminum to tungsten. Without radiation shielding, the measured radiation doses at this high repetition rate clearly exceed the regulatory limits. Estimations for an adequate radiation shielding are provided.

  14. On the Absence of Non-thermal X-Ray Emission around Runaway O Stars

    Energy Technology Data Exchange (ETDEWEB)

    Toalá, J. A. [Institute of Astronomy and Astrophysics, Academia Sinica (ASIAA), Taipei 10617, Taiwan (China); Oskinova, L. M. [Institute for Physics and Astronomy, University of Potsdam, D-14476 Potsdam (Germany); Ignace, R. [Department of Physics and Astronomy, East Tennessee State University, Johnson City, TN 37614 (United States)

    2017-04-01

    Theoretical models predict that the compressed interstellar medium around runaway O stars can produce high-energy non-thermal diffuse emission, in particular, non-thermal X-ray and γ -ray emission. So far, detection of non-thermal X-ray emission was claimed for only one runaway star, AE Aur. We present a search for non-thermal diffuse X-ray emission from bow shocks using archived XMM-Newton observations for a clean sample of six well-determined runaway O stars. We find that none of these objects present diffuse X-ray emission associated with their bow shocks, similarly to previous X-ray studies toward ζ Oph and BD+43°3654. We carefully investigated multi-wavelength observations of AE Aur and could not confirm previous findings of non-thermal X-rays. We conclude that so far there is no clear evidence of non-thermal extended emission in bow shocks around runaway O stars.

  15. Exotic x-ray emission from dense plasmas

    Czech Academy of Sciences Publication Activity Database

    Rosmej, F.B.; Dachicourt, R.; Deschaud, B.; Khaghani, D.; Dozières, M.; Šmíd, Michal; Renner, Oldřich

    2015-01-01

    Roč. 48, č. 22 (2015), s. 224005 ISSN 0953-4075 R&D Projects: GA MŠk ED1.1.00/02.0061 EU Projects: European Commission(XE) 284464 - LASERLAB-EUROPE Grant - others:ELI Beamlines(XE) CZ.1.05/1.1.00/02.0061; AVČR(CZ) M100101208 Institutional support: RVO:68378271 Keywords : hollow ions * x-ray spectroscopy * atomic physics Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 1.833, year: 2015

  16. Radio and X-ray emission from newly born remnants

    International Nuclear Information System (INIS)

    Salvati, M.

    1983-01-01

    Radio and X-ray observations of SN 1979c and SN 1980k offer a unique opportunity of monitoring the transition from supernovae to remnants. By means of the two-frequency radio light curves, the hypothesis that these objects are surrounded by circumstellar matter, originated in a presupernova wind, is tested, and the relevant parameters are derived. Then the absorption-corrected light curves are used to test the various proposed models. SN 1980k appears to be powered by a canonical shock, while SN 1979c is a good plerion candidate. An optical pulsar could still be detected at its location. (Auth.)

  17. Non-thermal Hard X-Ray Emission from Coma and Several Abell Clusters

    International Nuclear Information System (INIS)

    Correa, C

    2004-01-01

    We report results of hard X-Ray observations of the clusters Coma, Abell 496, Abell754, Abell 1060, Abell 1367, Abell2256 and Abell3558 using RXTE data from the NASA HEASARC public archive. Specifically we searched for clusters with hard x-ray emission that can be fitted by a power law because this would indicate that the cluster is a source of non-thermal emission. We are assuming the emission mechanism proposed by Vahk Petrosian where the inter cluster space contains clouds of relativistic electrons that by themselves create a magnetic field and emit radio synchrotron radiation. These relativistic electrons Inverse-Compton scatter Microwave Background photons up to hard x-ray energies. The clusters that were found to be sources of non-thermal hard x-rays are Coma, Abell496, Abell754 and Abell 1060

  18. Ultra-fast x-ray tomography for multi-phase flow interface dynamic studies

    International Nuclear Information System (INIS)

    Misawa, M.; Ichikawa, N.; Akai, M.; Tiseanu, I.; Prasser, H.-M.

    2003-01-01

    The present paper describes the concept of a fast scanning X-ray tomograph, the hardware development, and measurement results of gas-liquid two-phase flow in a vertical pipe. The device uses 18 pulsed X-ray sources activated in a successive order. In this way, a complete set of 18 independent projections of the object is obtained within 38 ms, i.e. the measuring rate is about 250 frames per second. Finally, to evaluate the measurement capability of the fast X-ray CT, a wire-mesh sensor was installed in the flow loop and both systems were operated for the same two-phase flow simultaneously. Comparison of the time series of the cross section averaged void fraction from both systems showed sufficient agreement for slug flow at large void fractions, while the fast CT underestimated the void fraction of bubbly flow especially in low void fraction range. For the wire-mesh sensor, coerced deformation of slug bubble interface was found. Further hardware improvement is in progress to achieve better resolution with the fast X-ray CT scanner. (orig.)

  19. SphinX MEASUREMENTS OF THE 2009 SOLAR MINIMUM X-RAY EMISSION

    International Nuclear Information System (INIS)

    Sylwester, J.; Kowalinski, M.; Gburek, S.; Siarkowski, M.; Bakała, J.; Gryciuk, M.; Podgorski, P.; Sylwester, B.; Kuzin, S.; Farnik, F.; Reale, F.; Phillips, K. J. H.

    2012-01-01

    The SphinX X-ray spectrophotometer on the CORONAS-PHOTON spacecraft measured soft X-ray emission in the 1-15 keV energy range during the deep solar minimum of 2009 with a sensitivity much greater than GOES. Several intervals are identified when the X-ray flux was exceptionally low, and the flux and solar X-ray luminosity are estimated. Spectral fits to the emission at these times give temperatures of 1.7-1.9 MK and emission measures between 4 × 10 47 cm –3 and 1.1 × 10 48 cm –3 . Comparing SphinX emission with that from the Hinode X-ray Telescope, we deduce that most of the emission is from general coronal structures rather than confined features like bright points. For one of 27 intervals of exceptionally low activity identified in the SphinX data, the Sun's X-ray luminosity in an energy range roughly extrapolated to that of ROSAT (0.1-2.4 keV) was less than most nearby K and M dwarfs.

  20. SphinX Measurements of the 2009 Solar Minimum X-Ray Emission

    Science.gov (United States)

    Sylwester, J.; Kowalinski, M.; Gburek, S.; Siarkowski, M.; Kuzin, S.; Farnik, F.; Reale, F.; Phillips, K. J. H.; Bakała, J.; Gryciuk, M.; Podgorski, P.; Sylwester, B.

    2012-06-01

    The SphinX X-ray spectrophotometer on the CORONAS-PHOTON spacecraft measured soft X-ray emission in the 1-15 keV energy range during the deep solar minimum of 2009 with a sensitivity much greater than GOES. Several intervals are identified when the X-ray flux was exceptionally low, and the flux and solar X-ray luminosity are estimated. Spectral fits to the emission at these times give temperatures of 1.7-1.9 MK and emission measures between 4 × 1047 cm-3 and 1.1 × 1048 cm-3. Comparing SphinX emission with that from the Hinode X-ray Telescope, we deduce that most of the emission is from general coronal structures rather than confined features like bright points. For one of 27 intervals of exceptionally low activity identified in the SphinX data, the Sun's X-ray luminosity in an energy range roughly extrapolated to that of ROSAT (0.1-2.4 keV) was less than most nearby K and M dwarfs.

  1. SphinX MEASUREMENTS OF THE 2009 SOLAR MINIMUM X-RAY EMISSION

    Energy Technology Data Exchange (ETDEWEB)

    Sylwester, J.; Kowalinski, M.; Gburek, S.; Siarkowski, M.; Bakala, J.; Gryciuk, M.; Podgorski, P.; Sylwester, B. [Space Research Centre, Polish Academy of Sciences, 51-622, Kopernika 11, Wroclaw (Poland); Kuzin, S. [P. N. Lebedev Physical Institute (FIAN), Russian Academy of Sciences, Leninsky Prospect 53, Moscow 119991 (Russian Federation); Farnik, F. [Astronomical Institute, Ondrejov Observatory (Czech Republic); Reale, F. [Dipartimento di Fisica, Universita di Palermo, Palermo, Italy, and INAF, Osservatorio Astronomico di Palermo, Palermo (Italy); Phillips, K. J. H., E-mail: js@cbk.pan.wroc.pl [Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Dorking, Surrey RH5 6NT (United Kingdom)

    2012-06-01

    The SphinX X-ray spectrophotometer on the CORONAS-PHOTON spacecraft measured soft X-ray emission in the 1-15 keV energy range during the deep solar minimum of 2009 with a sensitivity much greater than GOES. Several intervals are identified when the X-ray flux was exceptionally low, and the flux and solar X-ray luminosity are estimated. Spectral fits to the emission at these times give temperatures of 1.7-1.9 MK and emission measures between 4 Multiplication-Sign 10{sup 47} cm{sup -3} and 1.1 Multiplication-Sign 10{sup 48} cm{sup -3}. Comparing SphinX emission with that from the Hinode X-ray Telescope, we deduce that most of the emission is from general coronal structures rather than confined features like bright points. For one of 27 intervals of exceptionally low activity identified in the SphinX data, the Sun's X-ray luminosity in an energy range roughly extrapolated to that of ROSAT (0.1-2.4 keV) was less than most nearby K and M dwarfs.

  2. Fast parallel algorithms for the x-ray transform and its adjoint.

    Science.gov (United States)

    Gao, Hao

    2012-11-01

    Iterative reconstruction methods often offer better imaging quality and allow for reconstructions with lower imaging dose than classical methods in computed tomography. However, the computational speed is a major concern for these iterative methods, for which the x-ray transform and its adjoint are two most time-consuming components. The speed issue becomes even notable for the 3D imaging such as cone beam scans or helical scans, since the x-ray transform and its adjoint are frequently computed as there is usually not enough computer memory to save the corresponding system matrix. The purpose of this paper is to optimize the algorithm for computing the x-ray transform and its adjoint, and their parallel computation. The fast and highly parallelizable algorithms for the x-ray transform and its adjoint are proposed for the infinitely narrow beam in both 2D and 3D. The extension of these fast algorithms to the finite-size beam is proposed in 2D and discussed in 3D. The CPU and GPU codes are available at https://sites.google.com/site/fastxraytransform. The proposed algorithm is faster than Siddon's algorithm for computing the x-ray transform. In particular, the improvement for the parallel computation can be an order of magnitude. The authors have proposed fast and highly parallelizable algorithms for the x-ray transform and its adjoint, which are extendable for the finite-size beam. The proposed algorithms are suitable for parallel computing in the sense that the computational cost per parallel thread is O(1).

  3. Investigation of Lecturer's Chalk by x-ray Florescence and Fast Neutron Activation Techniques

    International Nuclear Information System (INIS)

    Hassan, M.F.

    2011-01-01

    Different samples of lecturer's chalk were studied, using X-ray florescence (XRF) and Fast Neutron Activation Analysis (FNAA) techniques to ensure the safety of its use. The K (X-rays) and the gamma-rays were measured, using Si(Li) and high-purity germanium (HPGe) spectrometers to detect and determine qualitatively and quantitatively the constituents of the studied samples. The concentrations of the elements (Ca and small traces of Al, Fe, Mg and Si) were measured and their presence was confirmed by gamma-ray, lifetime and/or XRF measurements.

  4. Soft x-ray emission from the direction of the Coma cluster

    International Nuclear Information System (INIS)

    Hayakawa, Satio; Tanaka, Yasuo; Yamashita, Koujun; Bleeker, J.A.M.; Deerenberg, A.J.M.

    1975-01-01

    A soft X-ray source was observed in the direction of the Coma cluster. The flux in the energy range 0.2--0.4 keV was found to change within a time scale shorter than 80 s. The fast transient and the energy spectrum prohibit identification of this source with the Coma cluster. It is suggested that this source belongs to a class of nearby transient soft X-ray sources. (auth.)

  5. AN XMM-NEWTON SURVEY OF THE SOFT X-RAY BACKGROUND. III. THE GALACTIC HALO X-RAY EMISSION

    International Nuclear Information System (INIS)

    Henley, David B.; Shelton, Robin L.

    2013-01-01

    We present measurements of the Galactic halo's X-ray emission for 110 XMM-Newton sight lines selected to minimize contamination from solar wind charge exchange emission. We detect emission from few million degree gas on ∼4/5 of our sight lines. The temperature is fairly uniform (median = 2.22 × 10 6 K, interquartile range = 0.63 × 10 6 K), while the emission measure and intrinsic 0.5-2.0 keV surface brightness vary by over an order of magnitude (∼(0.4-7) × 10 –3 cm –6 pc and ∼(0.5-7) × 10 –12 erg cm –2 s –1 deg –2 , respectively, with median detections of 1.9 × 10 –3 cm –6 pc and 1.5 × 10 –12 erg cm –2 s –1 deg –2 , respectively). The high-latitude sky contains a patchy distribution of few million degree gas. This gas exhibits a general increase in emission measure toward the inner Galaxy in the southern Galactic hemisphere. However, there is no tendency for our observed emission measures to decrease with increasing Galactic latitude, contrary to what is expected for a disk-like halo morphology. The measured temperatures, brightnesses, and spatial distributions of the gas can be used to place constraints on models for the dominant heating sources of the halo. We provide some discussion of such heating sources, but defer comparisons between the observations and detailed models to a later paper

  6. Globular clusters as a source of X-ray emission from the neighbourhood of M87

    International Nuclear Information System (INIS)

    Fabian, A.C.; Pringle, J.E.; Rees, M.J.

    1976-01-01

    It is stated that the X-ray emission from globular clusters may be attributable to accretion on to compact objects, the accreting material being supplied from binary companions, or gas trapped in the potential well of the cluster. Counts of objects in the vicinity of the M87 have revealed that it has an extensive halo of globular clusters, the number of which may exceed 10,000 within a radius of 23 arc min. Most of these clusters may be explicable as a population effect, and the similarity of their optical properties to those of cluster in our own Galaxy suggests that they may also contain X-ray sources. The brighter globular clusters in M87 may, however, be substantially more X-ray luminous, and there may be proportionally more gas available in globular clusters in M87 compared with our Galaxy. The average X-ray luminosity of individual globular clusters may be of the order of 10 38 erg/sec., which raises the possibility that the integrated globular cluster emission may account for a substantial fraction of the X-ray emission observed from the region of M87. In support of this it is noted that the extended X-ray emission from the Virgo cluster is centered on M87, which lies approximately 45 arc min from the cluster centroid, and it is expected that the general X-ray emission from the globular cluster will appear to be smoothly and symmetrically distributed about M87 at moderate spatial resolution. A similar situation may apply to the elliptical galaxy NGC 3311 in Abell 1060 which, as a cluster, has been suggested as the identification for the X-ray source 3 U 1044-40, and it seems possible that that galaxy is surrounded by a similar globular cluster population to that of M87. (U.K.)

  7. Particle Induced X-ray Emission (PIXE) Approach for the Quantification of Thin Al Films

    International Nuclear Information System (INIS)

    Younes, G; Zahraman, K; Nsouli, B; Soueidan, M; Ferro, G

    2008-01-01

    Particle Induced X-ray Emission (PIXE) has been used as a fast and non-destructive technique for sensitive characterization of ultra thin Al films deposited by evaporation onto Si substrate. In this work the PIXE technique was optimized, using proton beam at different energies and different angles of incidence, for the characterization of ultra thin Al films (few nanometers) deposited onto Si substrate. The PIXE results showed that a proton beam of 300 keV under tilting angle of 80 degree permits an accurate determination of Al with high sensitivity within few minutes of acquisition time and a LOD of less than 0.2 nm. The LOD versus energy and tilting angle will be presented and discussed. (author)

  8. Proton induced X-ray emission (PIXE) analysis at Lucas Heights

    International Nuclear Information System (INIS)

    Cohen, D.; Duerden, P.

    1979-02-01

    The state of the proton induced X-ray emission (PIXE) work at Lucas Heights is reported together with a full description of the experimental arrangement and its use for analysis of trace elements (Z >or= 14). The fundamentals of PIXE are examined in detail with a view to understanding not only the background continuum but also the X-ray production mechanisms. Quantitative predictions for the number of X-rays detected after proton bombardment of the target have been made and these compare well with experiments

  9. Time correlation between plasma behaviour and soft x-ray emission in a plasma focus

    International Nuclear Information System (INIS)

    Hirano, Katsumi; Tagaya, Yutaka; Shimoda, Katsuji; Okabe, Yushiro; Yamamoto, Toshikazu

    1986-01-01

    Soft X-rays emitted from a plasma focus are investigated experimentally. In contrast to single-pulsive burst of neutron, hard X-rays, ion- and electron beams, the soft X-rays are observed from the collapse phase to the decay phase of the plasma column, and have typically three successive peaks in its signal. Each peak corresponds to the maximum compression, the disruption and the decay phase of plasma column. It is revealed that the first and the second peaks are radiated by plasma itself, whereas the third peak is caused by emission from the inner electrode face. (author)

  10. X-ray emission in collisions of highly charged I, Pr, Ho, and Bi ions with a W surface

    International Nuclear Information System (INIS)

    Watanabe, H.; Tona, M.; Ohtani, S.; Sun, J.; Nakamura, N.; Yamada, C.; Yoshiyasu, N.; Sakurai, M.

    2007-01-01

    X-ray emission yields, which are defined as the total number of emitted x-ray photons per incident ion, and dissipated fractions of potential energies through x-ray emission have been measured for slow highly charged ions of I, Pr, Ho, and Bi colliding with a W surface. A larger amount of potential energy was consumed for the x-ray emission with increasing the atomic number and the charge state. The present measurements show that x-ray emission is one of the main decay channels of hollow atoms produced in collisions of very highly charged ions of heavy elements

  11. CVD diamond based soft X-ray detector with fast response

    International Nuclear Information System (INIS)

    Li Fang; Hou Lifei; Su Chunxiao; Yang Guohong; Liu Shenye

    2010-01-01

    A soft X-ray detector has been made with high quality chemical vapor deposited (CVD) diamond and the electrical structure of micro-strip. Through the measurement of response time on a laser with the pulse width of 10 ps, the full width at half maximum of the data got in the oscilloscope was 115 ps. The rise time of the CVD diamond detector was calculated to be 49 ps. In the experiment on the laser prototype facility, the signal got by the CVD diamond detector was compared with that got by a soft X-ray spectrometer. Both signals coincided well. The detector is proved to be a kind of reliable soft X-ray detector with fast response and high signal-to-noise ratio. (authors)

  12. Extended hard-X-ray emission in the inner few parsecs of the Galaxy

    DEFF Research Database (Denmark)

    Perez, Kerstin; Hailey, Charles J.; Bauer, Franz E.

    2015-01-01

    of objects emitting soft X-rays (less than 10 kiloelectronvolts) within the surrounding hundreds of parsecs, as well as the population responsible for unresolved X-ray emission extending along the Galactic plane, is dominated by accreting white dwarf systems. Observations of diffuse hard-X-ray (more than 10...... kiloelectronvolts) emission in the inner 10 parsecs, however, have been hampered by the limited spatial resolution of previous instruments. Here we report the presence of a distinct hard-X-ray component within the central 4 × 8 parsecs, as revealed by subarcminute-resolution images in the 20-40 kiloelectronvolt...... outflows interacting with the surrounding radiation field, dense molecular material or magnetic fields. However, all these interpretations pose significant challenges to our understanding of stellar evolution, binary formation, and cosmic-ray production in the Galactic Centre....

  13. Probing Photoinduced Structural Phase Transitions by Fast or Ultra-Fast Time-Resolved X-Ray Diffraction

    Science.gov (United States)

    Cailleau, Hervé Collet, Eric; Buron-Le Cointe, Marylise; Lemée-Cailleau, Marie-Hélène Koshihara, Shin-Ya

    A new frontier in the field of structural science is the emergence of the fast and ultra-fast X-ray science. Recent developments in time-resolved X-ray diffraction promise direct access to the dynamics of electronic, atomic and molecular motions in condensed matter triggered by a pulsed laser irradiation, i.e. to record "molecular movies" during the transformation of matter initiated by light pulse. These laser pump and X-ray probe techniques now provide an outstanding opportunity for the direct observation of a photoinduced structural phase transition as it takes place. The use of X-ray short-pulse of about 100ps around third-generation synchrotron sources allows structural investigations of fast photoinduced processes. Other new X-ray sources, such as laser-produced plasma ones, generate ultra-short pulses down to 100 fs. This opens the way to femtosecond X-ray crystallography, but with rather low X-ray intensities and more limited experimental possibilities at present. However this new ultra-fast science rapidly progresses around these sources and new large-scale projects exist. It is the aim of this contribution to overview the state of art and the perspectives of fast and ultra-fast X-ray scattering techniques to study photoinduced phase transitions (here, the word ultra-fast is used for sub-picosecond time resolution). In particular we would like to largely present the contribution of crystallographic methods in comparison with optical methods, such as pump-probe reflectivity measurements, the reader being not necessary familiar with X-ray scattering. Thus we want to present which type of physical information can be obtained from the positions of the Bragg peaks, their intensity and their shape, as well as from the diffuse scattering beyond Bragg peaks. An important physical feature is to take into consideration the difference in nature between a photoinduced phase transition and conventional homogeneous photoinduced chemical or biochemical processes where

  14. Electron and photon emissions from gold nanoparticles irradiated by X-ray photons

    Energy Technology Data Exchange (ETDEWEB)

    Casta, R., E-mail: castaromain@gmail.com, E-mail: romain.casta@irsamc.ups-tlse.fr; Champeaux, J.-P.; Moretto-Capelle, P.; Sence, M.; Cafarelli, P. [Université de Toulouse, UPS, Laboratoire Collisions Agrégats Réactivité, IRSAMC, CNRS, UMR 5589 (France)

    2015-01-15

    In this paper, we develop a totally new probabilistic model for the electron and photon emission of gold nanoparticles irradiated by X-ray photons. This model allows direct applications to recent researches about the radiotherapy enhancement by gold nanoparticles in the context of cancer treatment. Our model uses, in a complete original way, simulated Auger cascade and stopping power to compute electron emission spectra, photon emission spectra and released energy inside the material of gold nanoparticles. It allows us to present new results about the electron and photon emission of gold nanoparticle irradiated by hard X-rays.

  15. THERMAL X-RAY EMISSION FROM THE SHOCKED STELLAR WIND OF PULSAR GAMMA-RAY BINARIES

    Energy Technology Data Exchange (ETDEWEB)

    Zabalza, V.; Paredes, J. M. [Departament d' Astronomia i Meteorologia, Institut de Ciencies del Cosmos (ICC), Universitat de Barcelona (IEEC-UB), Marti i Franques 1, E08028 Barcelona (Spain); Bosch-Ramon, V., E-mail: vzabalza@am.ub.es [Dublin Institute for Advanced Studies, 31 Fitzwilliam Place, Dublin 2 (Ireland)

    2011-12-10

    Gamma-ray-loud X-ray binaries are binary systems that show non-thermal broadband emission from radio to gamma rays. If the system comprises a massive star and a young non-accreting pulsar, their winds will collide producing broadband non-thermal emission, most likely originated in the shocked pulsar wind. Thermal X-ray emission is expected from the shocked stellar wind, but until now it has neither been detected nor studied in the context of gamma-ray binaries. We present a semi-analytic model of the thermal X-ray emission from the shocked stellar wind in pulsar gamma-ray binaries, and find that the thermal X-ray emission increases monotonically with the pulsar spin-down luminosity, reaching luminosities of the order of 10{sup 33} erg s{sup -1}. The lack of thermal features in the X-ray spectrum of gamma-ray binaries can then be used to constrain the properties of the pulsar and stellar winds. By fitting the observed X-ray spectra of gamma-ray binaries with a source model composed of an absorbed non-thermal power law and the computed thermal X-ray emission, we are able to derive upper limits on the spin-down luminosity of the putative pulsar. We applied this method to LS 5039, the only gamma-ray binary with a radial, powerful wind, and obtain an upper limit on the pulsar spin-down luminosity of {approx}6 Multiplication-Sign 10{sup 36} erg s{sup -1}. Given the energetic constraints from its high-energy gamma-ray emission, a non-thermal to spin-down luminosity ratio very close to unity may be required.

  16. Some implications of excess soft X-ray emission from Seyfert 1 galaxies

    International Nuclear Information System (INIS)

    Fabian, A.C.; Guilbert, P.W.; Arnaud, K.A.; Shafer, R.A.; Tennant, A.F.; Ward, M.J.

    1986-01-01

    The X-ray spectrum of Seyfert 1 galaxies is characterized by a hard power-law spectrum. It is often postulated that this maintains a Compton-heated two-phase Broad-Line Region (BLR) around the central source. It is shown here that the strong excess soft X-ray emission observed in MKN 841 and other Seyfert galaxies invalidates this model if the BLR is spherically symmetric. Alternatives are proposed. (author)

  17. X-Ray Emission from Active Galactic Nuclei with Intermediate-Mass Black Holes

    Science.gov (United States)

    Dewangan, G. C.; Mathur, S.; Griffiths, R. E.; Rao, A. R.

    2008-12-01

    We present a systematic X-ray study of eight active galactic nuclei (AGNs) with intermediate-mass black holes (MBH ~ 8-95 × 104 M⊙) based on 12 XMM-Newton observations. The sample includes the two prototype AGNs in this class—NGC 4395 and POX 52 and six other AGNs discovered with the Sloan Digitized Sky Survey. These AGNs show some of the strongest X-ray variability, with the normalized excess variances being the largest and the power density break timescales being the shortest observed among radio-quiet AGNs. The excess-variance-luminosity correlation appears to depend on both the BH mass and the Eddington luminosity ratio. The break timescale-black hole mass relations for AGN with IMBHs are consistent with that observed for massive AGNs. We find that the FWHM of the Hβ/Hα line is uncorrelated with the BH mass, but shows strong anticorrelation with the Eddington luminosity ratio. Four AGNs show clear evidence for soft X-ray excess emission (kTin ~ 150-200 eV). X-ray spectra of three other AGNs are consistent with the presence of the soft excess emission. NGC 4395 with lowest L/LEdd lacks the soft excess emission. Evidently small black mass is not the primary driver of strong soft X-ray excess emission from AGNs. The X-ray spectral properties and optical-to-X-ray spectral energy distributions of these AGNs are similar to those of Seyfert 1 galaxies. The observed X-ray/UV properties of AGNs with IMBHs are consistent with these AGNs being low-mass extensions of more massive AGNs, those with high Eddington luminosity ratio looking more like narrow-line Seyfert 1 s and those with low L/LEdd looking more like broad-line Seyfert 1 galaxies.

  18. Elemental analysis of coal by proton-induced x-ray emission analysis

    International Nuclear Information System (INIS)

    Cronch, S.M.; Ehmann, W.D.; Laumer, H.W.; Gabbard, F.

    1976-01-01

    Proton-induced x-ray emission was used to determine elemental concentrations in solid coal samples. The coal samples were irradiated with 2.5 to 5.5 MeV protons. Concentrations were determined from characteristic x-ray yields taking into account matrix absorption. The precision is shown by replicate analysis and the accuracy by comparison with results obtained by other laboratories using different techniques

  19. X-Ray Emission from a Merger Remnant, NGC 7252 (the ``Atoms-for-Peace'' Galaxy)

    Science.gov (United States)

    Awaki, Hisamitsu; Matsumoto, Hironori; Tomida, Hiroshi

    2002-03-01

    We observed a nearby merger remnant NGC 7252 with the X-ray satellite ASCA and detected X-ray emission with the X-ray flux of (1.8+/-0.3)×10-13 ergs s-1 cm-2 in the 0.5-10 keV band. This corresponds to the X-ray luminosity of 8.1×1040 ergs s-1. The X-ray emission is well described with a two-component model: a soft component with kT=0.72+/-0.13 keV and a hard component with kT>5.1 keV. Although NGC 7252 is referred to as a dynamically young protoelliptical, the 0.5-4 keV luminosity of the soft component is about 2×1040 ergs s-1, which is low for an early-type galaxy. The ratio of LX/LFIR suggests that the soft component originated from the hot gas due to star formation. Its low luminosity can be explained by the gas ejection from the galaxy as galaxy winds. Our observation reveals the existence of hard X-ray emission with the 2-10 keV luminosity of 5.6×1040 ergs s-1. This may indicate the existence of nuclear activity or an intermediate-mass black hole in NGC 7252.

  20. NuSTAR HARD X-RAY SURVEY OF THE GALACTIC CENTER REGION. I. HARD X-RAY MORPHOLOGY AND SPECTROSCOPY OF THE DIFFUSE EMISSION

    Energy Technology Data Exchange (ETDEWEB)

    Mori, Kaya; Hailey, Charles J.; Perez, Kerstin; Nynka, Melania; Zhang, Shuo; Canipe, Alicia M. [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Krivonos, Roman; Tomsick, John A.; Barrière, Nicolas; Boggs, Steven E.; Craig, William W. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Hong, Jaesub [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Ponti, Gabriele [Max-Planck-Institut f. extraterrestrische Physik, HEG, Garching (Germany); Bauer, Franz [Instituto de Astrofísica, Facultad de Física, Pontificia Universidad Católica de Chile, 306, Santiago 22 (Chile); Alexander, David M. [Department of Physics, Durham University, Durham DH1 3LE (United Kingdom); Baganoff, Frederick K. [Kavli Institute for Astrophysics and Space Research, Massachusets Institute of Technology, Cambridge, MA 02139 (United States); Barret, Didier [Université de Toulouse, UPS-OMP, IRAP, Toulouse (France); Christensen, Finn E. [DTU Space—National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby (Denmark); Forster, Karl [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Giommi, Paolo, E-mail: kaya@astro.columbia.edu [ASI Science Data Center, Via del Politecnico snc I-00133, Roma (Italy); and others

    2015-12-01

    We present the first sub-arcminute images of the Galactic Center above 10 keV, obtained with NuSTAR. NuSTAR resolves the hard X-ray source IGR J17456–2901 into non-thermal X-ray filaments, molecular clouds, point sources, and a previously unknown central component of hard X-ray emission (CHXE). NuSTAR detects four non-thermal X-ray filaments, extending the detection of their power-law spectra with Γ ∼ 1.3–2.3 up to ∼50 keV. A morphological and spectral study of the filaments suggests that their origin may be heterogeneous, where previous studies suggested a common origin in young pulsar wind nebulae (PWNe). NuSTAR detects non-thermal X-ray continuum emission spatially correlated with the 6.4 keV Fe Kα fluorescence line emission associated with two Sgr A molecular clouds: MC1 and the Bridge. Broadband X-ray spectral analysis with a Monte-Carlo based X-ray reflection model self-consistently determined their intrinsic column density (∼10{sup 23} cm{sup −2}), primary X-ray spectra (power-laws with Γ ∼ 2) and set a lower limit of the X-ray luminosity of Sgr A* flare illuminating the Sgr A clouds to L{sub X} ≳ 10{sup 38} erg s{sup −1}. Above ∼20 keV, hard X-ray emission in the central 10 pc region around Sgr A* consists of the candidate PWN G359.95–0.04 and the CHXE, possibly resulting from an unresolved population of massive CVs with white dwarf masses M{sub WD} ∼ 0.9 M{sub ⊙}. Spectral energy distribution analysis suggests that G359.95–0.04 is likely the hard X-ray counterpart of the ultra-high gamma-ray source HESS J1745–290, strongly favoring a leptonic origin of the GC TeV emission.

  1. X-Rays from NGC 3256: High-Energy Emission in Starburst Galaxies and Their Contribution to the Cosmic X-Ray Background

    International Nuclear Information System (INIS)

    Moran, Edward C.; Lehnert, Matthew D.; Helfand, David J.

    1999-01-01

    The infrared-luminous galaxy NGC 3256 is a classic example of a merger-induced nuclear starburst system. We find here that it is the most X-ray-luminous star-forming galaxy yet detected (L 0.5-10keV =1.6x10 42 ergs s-1). Long-slit optical spectroscopy and a deep, high-resolution ROSAT X-ray image show that the starburst is driving a ''superwind'' which accounts for ∼20% of the observed soft X-ray emission. Analysis of X-ray spectral data from ASCA indicates this gas has a characteristic temperature of kT≅0.3 keV. Our model for the broadband X-ray emission of NGC 3256 contains two additional components: a warm thermal plasma (kT≅0.8 keV) associated with the central starburst, and a hard power-law component with an energy index of α X ≅0.7. We discuss the energy budget for the two thermal plasmas and find that the input of mechanical energy from the starburst is more than sufficient to sustain the observed level of emission. We also examine possible origins for the power-law component, concluding that neither a buried AGN nor the expected population of high-mass X-ray binaries can account for this emission. Inverse Compton scattering, involving the galaxy's copious flux of infrared photons and the relativistic electrons produced by supernovae, is likely to make a substantial contribution to the hard X-ray flux. Such a model is consistent with the observed radio and IR fluxes and the radio and X-ray spectral indices. We explore the role of X-ray-luminous starbursts in the production of the cosmic X-ray background radiation. The number counts and spectral index distribution of the faint radio source population, thought to be dominated by star-forming galaxies, suggest that a significant fraction of the hard X-ray background could arise from starbursts at moderate redshift. (c) (c) 1999. The American Astronomical Society

  2. Microwave and X-Ray emission during a isentropic expansion and its application to solar bursts

    International Nuclear Information System (INIS)

    Piazza, L.R.

    1983-01-01

    The gyro-synchrotron emission in microwaves and the free-free emission in X-rays of a plasma enclosed in a cylinder coincident with a magnetic force tube were calculated for an isentropic self-similar expansion, with plane and cylindrical symmetries. This expansion model was applied to a region of the low solar corona, and the results were compared to the emission observed in some simple solar events of low intensity. The calculations show satisfactory coincidence with the events in X-rays for energies around 10 29 ergs. The solar events analyzed in microwaves, which are not the same that were studied in X-rays, in general do not fit the theoretical results. The origin of the discrepancy is probably the formulation of the processes of emission applied to the expansion. (Author) [pt

  3. Hard x ray imaging and the relative contribution of thermal and nonthermal emission in flares

    International Nuclear Information System (INIS)

    Holman, G.D.

    1986-01-01

    The question of whether the impulsive 25 to 100 keV x ray emission from solar flares is thermal or nonthermal has been a long-standing controversy. Both thermal and nonthermal (beam) models have been developed and applied to the hard x ray data. It now seems likely that both thermal and nonthermal emission have been observed at hard x ray energies. The Hinotori classification scheme, for example, is an attempt to associate the thermal-nonthermal characteristics of flare hard x ray emission with other flare properties. From a theoretical point of view, it is difficult to generate energetic, nonthermal electrons without dumping an equal or greater amount of energy into plasma heating. On the other hand, any impulsive heating process will invariably generate at least some nonthermal particles. Hence, strictly speaking, although thermal or nonthermal emission may dominate the hard x ray emission in a given energy range for a given flare, there is no such thing as a purely thermal or nonthermal flare mechanism

  4. Lifetime-vibrational interference effects in resonantly excited x-ray emission spectra of CO

    Energy Technology Data Exchange (ETDEWEB)

    Skytt, P.; Glans, P.; Gunnelin, K. [Uppsala Univ. (Sweden)] [and others

    1997-04-01

    The parity selection rule for resonant X-ray emission as demonstrated for O{sub 2} and N{sub 2} can be seen as an effect of interference between coherently excited degenerate localized core states. One system where the core state degeneracy is not exact but somewhat lifted was previously studied at ALS, namely the resonant X-ray emission of amino-substituted benzene (aniline). It was shown that the X-ray fluorescence spectrum resulting from excitation of the C1s at the site of the {open_quotes}aminocarbon{close_quotes} could be described in a picture separating the excitation and the emission processes, whereas the spectrum corresponding to the quasi-degenerate carbons could not. Thus, in this case it was necessary to take interference effects between the quasi-degenerate intermediate core excited states into account in order to obtain agreement between calculations and experiment. The different vibrational levels of core excited states in molecules have energy splittings which are of the same order of magnitude as the natural lifetime broadening of core excitations in the soft X-ray range. Therefore, lifetime-vibrational interference effects are likely to appear and influence the band shapes in resonant X-ray emission spectra. Lifetime-vibrational interference has been studied in non-resonant X-ray emission, and in Auger spectra. In this report the authors discuss results of selectively excited soft X-ray fluorescence spectra of molecules, where they focus on lifetime-interference effects appearing in the band shapes.

  5. X-ray-based attenuation correction for positron emission tomography/computed tomography scanners.

    Science.gov (United States)

    Kinahan, Paul E; Hasegawa, Bruce H; Beyer, Thomas

    2003-07-01

    A synergy of positron emission tomography (PET)/computed tomography (CT) scanners is the use of the CT data for x-ray-based attenuation correction of the PET emission data. Current methods of measuring transmission use positron sources, gamma-ray sources, or x-ray sources. Each of the types of transmission scans involves different trade-offs of noise versus bias, with positron transmission scans having the highest noise but lowest bias, whereas x-ray scans have negligible noise but the potential for increased quantitative errors. The use of x-ray-based attenuation correction, however, has other advantages, including a lack of bias introduced from post-injection transmission scanning, which is an important practical consideration for clinical scanners, as well as reduced scan times. The sensitivity of x-ray-based attenuation correction to artifacts and quantitative errors depends on the method of translating the CT image from the effective x-ray energy of approximately 70 keV to attenuation coefficients at the PET energy of 511 keV. These translation methods are usually based on segmentation and/or scaling techniques. Errors in the PET emission image arise from positional mismatches caused by patient motion or respiration differences between the PET and CT scans; incorrect calculation of attenuation coefficients for CT contrast agents or metallic implants; or keeping the patient's arms in the field of view, which leads to truncation and/or beam-hardening (or x-ray scatter) artifacts. Proper interpretation of PET emission images corrected for attenuation by using the CT image relies on an understanding of the potential artifacts. In cases where an artifact or bias is suspected, careful inspection of all three available images (CT and PET emission with and without attenuation correction) is recommended. Copyright 2003 Elsevier Inc. All rights reserved.

  6. X ray emission: a tool and a probe for laser - clusters interaction

    International Nuclear Information System (INIS)

    Prigent, Ch.

    2004-12-01

    In intense laser-cluster interaction, the experimental results show a strong energetic coupling between radiation and matter. We have measured absolute X-ray yields and charge state distributions under well control conditions as a function of physical parameters governing the interaction; namely laser intensity, pulse duration, wavelength or polarization state of the laser light, the size and the species of the clusters (Ar, Kr, Xe). We have highlighted, for the first time, an intensity threshold in the X-ray production very low (∼ 2.10 14 W/cm 2 for a pulse duration of 300 fs) which can results from an effect of the dynamical polarisation of clusters in an intense electric field. A weak dependence with the wavelength (400 nm / 800 nm) on the absolute X-ray yields has been found. Moreover, we have observed a saturation of the X-ray emission probability below a critical cluster size. (author)

  7. Magnetar-like X-Ray Bursts Suppress Pulsar Radio Emission

    Energy Technology Data Exchange (ETDEWEB)

    Archibald, R. F.; Lyutikov, M.; Kaspi, V. M.; Tendulkar, S. P. [Department of Physics and McGill Space Institute, McGill University, 3600 University Street, Montreal, QC H3A 2T8 (Canada); Burgay, M.; Possenti, A. [INAF–Osservatorio Astronomico di Cagliari, Via della Scienza 5, I-09047 Selargius (Italy); Esposito, P.; Rea, N. [Anton Pannekoek Institute for Astronomy, University of Amsterdam, Postbus 94249, 1090 GE Amsterdam (Netherlands); Israel, G. [INAF–Osservatorio Astronomico di Roma, via Frascati 33, I-00040 Monteporzio Catone, Roma (Italy); Kerr, M. [Space Science Division, Naval Research Laboratory, Washington, DC 20375-5352 (United States); Sarkissian, J. [CSIRO Astronomy and Space Science, Parkes Observatory, P.O. Box 276, Parkes, NSW 2870 (Australia); Scholz, P., E-mail: archibald@astro.utoronto.ca [National Research Council of Canada, Herzberg Astronomy and Astrophysics, Dominion Radio Astrophysical Observatory, P.O. Box 248, Penticton, BC V2A 6J9 (Canada)

    2017-11-10

    Rotation-powered pulsars and magnetars are two different observational manifestations of neutron stars: rotation-powered pulsars are rapidly spinning objects that are mostly observed as pulsating radio sources, while magnetars, neutron stars with the highest known magnetic fields, often emit short-duration X-ray bursts. Here, we report simultaneous observations of the high-magnetic-field radio pulsar PSR J1119−6127 at X-ray, with XMM-Newton and NuSTAR , and at radio energies with the Parkes radio telescope, during a period of magnetar-like bursts. The rotationally powered radio emission shuts off coincident with the occurrence of multiple X-ray bursts and recovers on a timescale of ∼70 s. These observations of related radio and X-ray phenomena further solidify the connection between radio pulsars and magnetars and suggest that the pair plasma produced in bursts can disrupt the acceleration mechanism of radio-emitting particles.

  8. Specific features of thermocouple calorimeter application for measurements of pulsed X-ray emission from plasma

    International Nuclear Information System (INIS)

    Gavrilov, V. V.; Fasakhov, I. K.

    2012-01-01

    It is shown that the accuracy of time-integrated measurements of pulsed X-ray emission from hot plasma with calibrated thermocouple calorimeters is mainly determined by two factors. The first and the most important factor is heating of the filter by the absorbed X-rays; as a result, the calorimeter measures the thermal radiation of the filter, which causes appreciable distortion of the temporal profile and amplitude of the recorded signal. The second factor is the dependence of the effective depth of X-ray absorption in the dielectric that covers the entrance window of the calorimeter on the energy of X-ray photons, i.e., on the recorded radiation spectrum. The results of model calculations of the calorimeter signal are compared with the experimental data.

  9. A Non-thermal Pulsed X-Ray Emission of AR Scorpii

    Science.gov (United States)

    Takata, J.; Hu, C.-P.; Lin, L. C. C.; Tam, P. H. T.; Pal, P. S.; Hui, C. Y.; Kong, A. K. H.; Cheng, K. S.

    2018-02-01

    We report the analysis result of UV/X-ray emission from AR Scorpii, which is an intermediate polar (IP) composed of a magnetic white dwarf and an M-type star, with the XMM-Newton data. The X-ray/UV emission clearly shows a large variation over the orbit, and their intensity maximum (or minimum) is located at the superior conjunction (or inferior conjunction) of the M star orbit. The hardness ratio of the X-ray emission shows a small variation over the orbital phase and shows no indication of the absorption by an accretion column. These properties are naturally explained by the emission from the M star surface rather than that from the accretion column on the white dwarf’s (WD) star, which is similar to usual IPs. Additionally, the observed X-ray emission also modulates with the WD’s spin with a pulse fraction of ∼14%. The peak position is aligned in the optical/UV/X-ray band. This supports the hypothesis that the electrons in AR Scorpii are accelerated to a relativistic speed and emit non-thermal photons via the synchrotron radiation. In the X-ray bands, evidence of the power-law spectrum is found in the pulsed component, although the observed emission is dominated by the optically thin thermal plasma emissions with several different temperatures. It is considered that the magnetic dissipation/reconnection process on the M star surface heats up the plasma to a temperature of several keV and also accelerates the electrons to the relativistic speed. The relativistic electrons are trapped in the WD’s closed magnetic field lines by the magnetic mirror effect. In this model, the observed pulsed component is explained by the emissions from the first magnetic mirror point.

  10. Spatially Resolved Hard X-ray Emission in the Central 5 kpc of the Galaxy Merger NGC 6240

    Science.gov (United States)

    Wang, Junfeng; Nardini, E.; Fabbiano, G.; Karovska, M.; Elvis, M.; Pellegrini, S.; Max, C. E.; Risaliti, G.; U, V.; Zezas, A.

    2013-04-01

    We have obtained a deep, sub-arcsecond resolution X-ray image of the nuclear region of the luminous galaxy merger NGC 6240 with Chandra, which resolves the X-ray emission from the pair of active nuclei and the diffuse hot gas in great detail. We detect extended hard X-ray emission from 70 million K hot gas over a spatial scale of 5 kpc, indicating the presence of fast shocks with velocity of 2200 km/s. For the first time we obtain spatial distribution of this highly ionized gas emitting FeXXV and find that it shows a remarkable correspondence to the large scale morphology of H_2(1-0) S(1) line emission and Hα filaments. Propagation of fast shocks originated in the starburst driven wind into the ambient dense gas can account for this morphological correspondence. Both the energetics and the iron mass in the hot gas are consistent with the expected injection from the supernovae explosion during the starburst that is commensurate with its high star formation rate.

  11. Time Variabilities of Solar Wind Ion Fluxes and of X-ray and EUV Emissions from Comet Hyakutake

    Science.gov (United States)

    Neugebauer, M.; Cravens, T.; Lisse, C.; Ipavich, F.; von Steiger, R.; Shah, P.; Armstrong, T.

    1999-01-01

    Observations of X-ray and extreme ultraviolet (EUV) emissions from comet C/Hyakutake 1996 B2 made by the Rontgen X-ray satellite (ROSAT) and the Extreme Ultraviolet Explorer (EUVE) revealed a total X-ray luminosity of about 500 MW.

  12. Statistical analysis of fast hard X-ray bursts by SMM observations and microwave bursts by ground-based observations

    Science.gov (United States)

    Li, Chun-Sheng; Jiang, Shu-Ying

    1986-01-01

    In order to understand the relationship between fast hard X-ray bursts (HXRB) and microwave bursts (MWB), data were used from the following publications: NASA Technical Memorandum 84998; Solar Geological Data (1980 to 1983); monthly report of Solar Radio Emission; and NASA and NSF: Solar Geophysical Data (1980 to 1983). For analyzing individual events, the criterion of the same event for HXRB and MWB is determined by peak time difference. There is a good linear correlation between the physical parameter of HXRB and MWB.

  13. Discovery of Diffuse Hard X-ray Emission associated with Jupiter

    Science.gov (United States)

    Ezoe, Y.; Miyoshi, Y.; Ishikawa, K.; Ohashi, T.; Terada, N.; Uchiyama, Y.; Negoro, H.

    2009-12-01

    Our discovery of diffuse hard (1-5 keV) X-ray emission around Jupiter is reported. Recent Chandra and XMM-Newton observations revealed several types of X-rays in the vicinity of Jupiter such as auroral and disk emission from Jupiter and faint diffuse X-rays from the Io Plasma Torus (see Bhardwaj et al. 2007 for review). To investigate possible diffuse hard X-ray emission around Jupiter with the highest sensitivity, we conducted data analysis of Suzaku XIS observations of Jupiter on Feb 2006. After removing satellite and planetary orbital motions, we detected a significant diffuse X-ray emission extending to ~6 x 3 arcmin with the 1-5 keV X-ray luminosity of ~3e15 erg/s. The emitting region very well coincided with the Jupiter's radiation belts. The 1-5 keV X-ray spectrum was represented by a simple power law model with a photon index of 1.4. Such a flat continuum strongly suggests non-thermal origin. Although such an emission can be originated from multiple background point sources, its possibility is quite low. We hence examined three mechanisms, assuming that the emission is truly diffuse: bremsstrahlung by keV electrons, synchrotron emission by TeV electrons, and inverse Compton scattering of solar photons by MeV electrons. The former two can be rejected because of the X-ray spectral shape and implausible existence of TeV electrons around Jupiter, respectively. The last possibility was found to be possible because tens MeV electrons, which have been confirmed in inner radiation belts (Bolton et al. 2002), can kick solar photons to the keV energy range and provide a simple power-law continuum. We estimated an average electron density from the X-ray luminosity assuming the oblate spheroid shaped emitting region with 8 x 8 x 4 Jovian radii. The necessary density was 0.02 1/cm3 for 50 MeV electrons. Hence, our results may suggest a new particle acceleration phenomenon around Jupiter.

  14. Electron and X-ray emission in collisions of multiply charged ions and atoms

    International Nuclear Information System (INIS)

    Woerlee, P.H.

    1979-01-01

    The author presents experimental results of electron and X-ray emission following slow collisions of multiply charged ions and atoms. The aim of the investigation was to study the mechanisms which are responsible for the emission. (G.T.H.)

  15. X-RAY EMISSION FROM SN 2004dj: A TALE OF TWO SHOCKS

    Energy Technology Data Exchange (ETDEWEB)

    Chakraborti, Sayan; Yadav, Naveen; Ray, Alak [Tata Institute of Fundamental Research, 1 Homi Bhabha Road, Colaba, Mumbai 400 005 (India); Smith, Randall [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Chandra, Poonam [Department of Physics, Royal Military College of Canada, Kingston, ON K7K 7B4 (Canada); Pooley, David, E-mail: schakraborti@fas.harvard.edu [Department of Physics, Sam Houston State University, Huntsville, TX (United States)

    2012-12-20

    Type IIP (Plateau) supernovae are the most commonly observed variety of core-collapse events. They have been detected in a wide range of wavelengths from radio, through optical to X-rays. The standard picture of a Type IIP supernova has the blastwave interacting with the progenitor's circumstellar matter to produce a hot region bounded by a forward and a reverse shock. This region is thought to be responsible for most of the X-ray and radio emission from these objects. Yet the origin of X-rays from these supernovae is not well understood quantitatively. The relative contributions of particle acceleration and magnetic field amplification in generating the X-ray and radio emission need to be determined. In this work, we analyze archival Chandra observations of SN 2004dj, one of the nearest supernovae since SN 1987A, along with published radio and optical information. We determine the pre-explosion mass-loss rate, blastwave velocity, electron acceleration, and magnetic field amplification efficiencies. We find that a greater fraction of the thermal energy goes into accelerating electrons than into amplifying magnetic fields. We conclude that the X-ray emission arises out of a combination of inverse Compton scattering by non-thermal electrons accelerated in the forward shock and thermal emission from supernova ejecta heated by the reverse shock.

  16. Ultrafast emission from colloidal nanocrystals under pulsed X-ray excitation

    CERN Document Server

    Turtos, R.M.; Polovitsyn, A.; Christodoulou, S.; Salomoni, M.; Auffray, E.; Moreels, I.; Lecoq, P.; Grim, J.Q.

    2016-01-01

    Fast timing has emerged as a critical requirement for radiation detection in medical and high energy physics, motivating the search for scintillator materials with high light yield and fast time response. However, light emission rates from conventional scintillation mechanisms fundamentally limit the achievable time resolution, which is presently at least one order of magnitude slower than required for next-generation detectors. One solution to this challenge is to generate an intense prompt signal in response to ionizing radiation. In this paper, we present colloidal semiconductor nanocrystals (NCs) as promising prompt photon sources. We investigate two classes of NCs: two-dimensional CdSe nanoplatelets (NPLs) and spherical CdSe/CdS core/giant shell quantum dots (GS QDs). We demonstrate that the emission rates of these NCs under pulsed X-ray excitation are much faster than traditional mechanisms in bulk scintillators, i.e. 5d-4f transitions. CdSe NPLs have a sub-100 ps effective decay time of 77 ps and CdSe/...

  17. Modelling of X-ray emission supernova remnants observed by the European satellite XMM-Newton

    International Nuclear Information System (INIS)

    Cassam-Chenai, G.

    2004-01-01

    This thesis deals with the X-ray emission of supernova remnants (SNRs) observed by the European satellite XMM-Newton. In SNRs, the matter heated to millions of degrees shines brightly in X-rays. This emission depends on the hydrodynamical evolution of the SNR, on the chemical composition of the ejected matter and on the ambient medium. Moreover, the blast-wave is considered to be the prime site of the production and the acceleration of cosmic-rays in our Galaxy. XMM-Newton is one of the first to allow the investigation of these different aspects thanks to its spatially-resolved spectroscopy and its very good sensitivity. l first studied Kepler's SNR (SN 1604) whose X-ray emission is dominated by the ejecta. Its observation has allowed to obtain information on the nucleosynthesis products, on their spatial distribution and on the temperature structure in the shocked ejecta. This gives strong constraints on the physics of the explosion and on the progenitor's type. l have shown also that the X-ray emission at the shock is likely to be non-thermal. Then, l studied the SNR G347.3-0.5 whose X-ray emission is entirely due to the synchrotron radiation of relativistic (TeV) electrons accelerated at the shock. From five pointing, l made a full mapping of the X-ray emission characteristics (brightness, absorption and spectral index) at small scale. Combined to radio observations, these results have indicated a clear interaction between the SNR and molecular clouds located at 1 kpc and not at 6 kpc as previously estimated. Lastly, in the framework of a self-similar hydrodynamical model coupled with non-linear particle acceleration, l have obtained the synchrotron emission profile in SNRs, including the adiabatic and radiative losses of the accelerated electrons. (author) [fr

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

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, M.; Kastner, J. H. [Center for Imaging Science and Laboratory for Multiwavelength Astrophysics, Rochester Institute of Technology, 54 Lomb Memorial Drive, Rochester, NY 14623 (United States); Montez, R. Jr. [Department of Physics and Astronomy, Vanderbilt University, Nashville, TN (United States); Balick, B. [Department of Astronomy, University of Washington, Seattle, WA (United States); Frew, D. J.; De Marco, O.; Parker, Q. A. [Department of Physics and Astronomy and Macquarie Research Centre for Astronomy, Astrophysics and Astrophotonics, Macquarie University, Sydney, NSW 2109 (Australia); Jones, D. [Departamento de Física, Universidad de Atacama, Copayapu 485, Copiapó (Chile); Miszalski, B. [South African Astronomical Observatory, P.O. Box 9, Observatory, 7935 (South Africa); Sahai, R. [Jet Propulsion Laboratory, MS 183-900, California Institute of Technology, Pasadena, CA 91109 (United States); Blackman, E.; Frank, A. [Department of Physics and Astronomy, University of Rochester, Rochester, NY (United States); Chu, Y.-H. [Department of Astronomy, University of Illinois at Urbana-Champaign, Urbana, IL (United States); Guerrero, M. A. [Instituto de Astrofísica de Andalucía, IAA-CSIC, Glorieta de la Astronomía s/n, Granada, E-18008 (Spain); Lopez, J. A. [Instituto de Astronomía, Universidad Nacional Autonoma de Mexico, Campus Ensenada, Apdo. Postal 22860, Ensenada, B. C. (Mexico); Zijlstra, A. [School of Physics and Astronomy, University of Manchester, Manchester M13 9PL (United Kingdom); Bujarrabal, V. [Instituto de Astrofísica de Canarias, E-38200 La Laguna, Tenerife (Spain); Corradi, R. L. M. [Departamento de Astrofísica, Universidad de La Laguna, E-38206 La Laguna, Tenerife (Spain); Nordhaus, J. [NSF Astronomy and Astrophysics Fellow, Center for Computational Relativity and Gravitation, Rochester Institute of Technology, Rochester, NY 14623 (United States); 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.

  19. A study of x-ray emission from the anode region in a plasma focus device

    International Nuclear Information System (INIS)

    Jia Wang; Tsinchi Yang

    1988-01-01

    The physical process of x-ray emission from the anode region in a plasma focus device due to the interaction of a powerful electron beam with the metal anode and with ionised metallic vapour from the anode is investigated. The influence of the magnetic field of the beam is taken into consideration. A MC-PIC model (Monte Carlo-particle in cell) is proposed for the process, in which an electron-photon collision cascade is simulated by the MC approach and the time-dependent state of metallic vapour is determined by PIC computation. The time-resolved energy spectra and angular distributions of x-ray emission from the extending anode region are calculated. The time-integrated characteristics of the x-ray emission can be compared with the results of experiments as far as they are available. (author)

  20. Trace analysis in cadmium telluride by heavy ion induced X-ray emission and by SIMS

    International Nuclear Information System (INIS)

    Scharager, C.; Stuck, R.; Siffert, P.; Cailleret, J.; Heitz, Ch.; Lagarde, G.; Tenorio, D.

    1979-01-01

    The possibilities of using both selective heavy ion induced X-ray emission and secondary ion mass spectroscopy (SIMS), for the identification of impurities present at low concentrations in cadmium telluride are examined. The relative concentrations of the impurities along CdTe crystals have been determined by exciting the X-ray emission of the elements in several slices with Ar and Kr ions and by comparing the relative characteristic X-ray emission yields. As a consequence of the quasimolecular inner shell ionization mechanism in heavy ion-atom collisions, Ar and Kr ions allow a strong excitation of the main impurities seen by SIMS namely Si, Cl and Ge, As, with only a minor contribution of Cd and Te. From the changes of the concentrations of the various impurities along the crystal, informations about segregation coefficients and compensation can be obtained

  1. High resolution krypton M/sub 4,5/ x-ray emission spectra

    International Nuclear Information System (INIS)

    Perera, R.C.C.; Hettrick, M.C.; Lindle, D.W.

    1987-10-01

    High resolution M/sub 4,5/ (3d → 4p) x-ray emission spectra from a krypton plasma were measured using a recently developed grazing-incidence reflection-grating monochromator/spectrometer with very high flux rates at extreme ultraviolet and soft x-ray wave lengths. The nominal resolving power of the instrument, E/ΔE, is about 300 in this energy range (∼80 eV). Three dipole-allowed 3d → 4p emission lines were observed at 80.98 eV, 80.35 eV and 79.73 eV. A broad peak at about 82.3 eV is tentatively assigned to transitions resulting from Kr 2+ , and effects of excitation energy on M/sub 4,5/ x-ray emission were observed. 9 refs., 3 figs., 1 tab

  2. Trends in hard X-ray fluorescence mapping: environmental applications in the age of fast detectors

    Energy Technology Data Exchange (ETDEWEB)

    Lombi, E.; Donner, E. [University of South Australia, Centre for Environmental Risk Assessment and Remediation, Mawson Lakes, South Australia (Australia); CRC CARE, PO Box 486, Salisbury, South Australia (Australia); Jonge, M.D. de; Paterson, D. [Australian Synchrotron, X-ray Fluorescence Microscopy, 800 Blackburn Road, Clayton, Victoria (Australia); Ryan, C.G. [CSIRO Earth Science and Resource Engineering, Normanby Road, Clayton, Victoria (Australia)

    2011-06-15

    Environmental samples are extremely diverse but share a tendency for heterogeneity and complexity. This heterogeneity poses methodological challenges when investigating biogeochemical processes. In recent years, the development of analytical tools capable of probing element distribution and speciation at the microscale have allowed this challenge to be addressed. Of these available tools, laterally resolved synchrotron techniques such as X-ray fluorescence mapping are key methods for the in situ investigation of micronutrients and inorganic contaminants in environmental samples. This article demonstrates how recent advances in X-ray fluorescence detector technology are bringing new possibilities to environmental research. Fast detectors are helping to circumvent major issues such as X-ray beam damage of hydrated samples, as dwell times during scanning are reduced. They are also helping to reduce temporal beamtime requirements, making particularly time-consuming techniques such as micro X-ray fluorescence ({mu}XRF) tomography increasingly feasible. This article focuses on {mu}XRF mapping of nutrients and metalloids in environmental samples, and suggests that the current divide between mapping and speciation techniques will be increasingly blurred by the development of combined approaches. (orig.)

  3. Fast solar hard X-ray bursts and large scale coronal structures

    International Nuclear Information System (INIS)

    Simnett, G.M.

    1982-01-01

    The conditions at the Sun at the times corresponding to a selected set 22 fast impulsive hard X-ray bursts reported by Crannell et al. are examined. It is suggested that one of the bursts must arise from a precipitating beam of subrelativistic electrons; the source of the electrons is postulated to be in a region very remote from the X-ray site on the basis of type III and other radio data. The connection is via a coronal magnetic loop extending to approx.3 R/sub sun/ above the photosphere. The energy in the electron beam is estimated at 3 x 10 27 ergs. Intense soft X-ray and/or microwave radio storms at times corresponding to many of the impulsive X-ray bursts lead the conclusion that 14, and possibly 18, of the 22 bursts could have the same interpretation. The energy in such an electron beam could be important when considering the trigger phase of some flares

  4. Neural network Hilbert transform based filtered backprojection for fast inline x-ray inspection

    Science.gov (United States)

    Janssens, Eline; De Beenhouwer, Jan; Van Dael, Mattias; De Schryver, Thomas; Van Hoorebeke, Luc; Verboven, Pieter; Nicolai, Bart; Sijbers, Jan

    2018-03-01

    X-ray imaging is an important tool for quality control since it allows to inspect the interior of products in a non-destructive way. Conventional x-ray imaging, however, is slow and expensive. Inline x-ray inspection, on the other hand, can pave the way towards fast and individual quality control, provided that a sufficiently high throughput can be achieved at a minimal cost. To meet these criteria, an inline inspection acquisition geometry is proposed where the object moves and rotates on a conveyor belt while it passes a fixed source and detector. Moreover, for this acquisition geometry, a new neural-network-based reconstruction algorithm is introduced: the neural network Hilbert transform based filtered backprojection. The proposed algorithm is evaluated both on simulated and real inline x-ray data and has shown to generate high quality reconstructions of 400  ×  400 reconstruction pixels within 200 ms, thereby meeting the high throughput criteria.

  5. Ultrafast atomic process in X-ray emission by using inner-shell ionization method for sodium and carbon atoms

    Energy Technology Data Exchange (ETDEWEB)

    Moribayashi, Kengo; Sasaki, Akira; Tajima, Toshiki [Japan Atomic Energy Research Inst., Neyagawa, Osaka (Japan). Kansai Research Establishment

    1998-07-01

    An ultrafast inner-shell ionization process with X-ray emission stimulated by high-intensity short-pulse X-ray is studied. Carbon and sodium atoms are treated as target matter. It is shown that atomic processes of the target determine the necessary X-ray intensity for X-ray laser emission as well as the features of X-ray laser such as wavelength and duration time. The intensity also depends on the density of initial atoms. Furthermore, we show that as the intensity of X-ray source becomes high, the multi-inner-shell ionization predominates, leading to the formation of hollow atoms. As the density of hollow atoms is increased by the pumping X-ray power, the emission of X-rays is not only of significance for high brightness X-ray measurement but also is good for X-ray lasing. New classes of experiments of pump X-ray probe and X-ray laser are suggested. (author)

  6. X-ray absorption spectra and emission spectra of plasmas

    International Nuclear Information System (INIS)

    Peng Yonglun; Yang Li; Wang Minsheng; Li Jiaming

    2002-01-01

    The author reports a theoretical method to calculate the resolved absorption spectra and emission spectra (optically thin) of hot dense plasmas. Due to its fully relativistic treatment incorporated with the quantum defect theory, it calculates the absorption spectra and emission spectra for single element or multi-element plasmas with little computational efforts. The calculated absorption spectra of LTE gold plasmas agree well with the experimental ones. It also calculates the optical thin emission spectra of LTE gold plasmas, which is helpful to diagnose the plasmas of relevant ICF plasmas. It can also provide the relevant parameters such as population density of various ionic stages, precise radiative properties for ICF studies

  7. MODELING THE THERMAL DIFFUSE SOFT AND HARD X-RAY EMISSION IN M17

    International Nuclear Information System (INIS)

    Velázquez, P. F.; Rodríguez-González, A.; Esquivel, A.; Rosado, M.; Reyes-Iturbide, J.

    2013-01-01

    We present numerical models of very young wind driven superbubbles. The parameters chosen for the simulations correspond to the particular case of the M17 nebula, but are appropriate for any young superbubble in which the wind sources have not completely dispersed their parental cloud. From the simulations, we computed the diffuse emission in the soft ([0.5-1.5] keV) and hard ([1.5-5] keV) X-ray bands. The total luminosity in our simulations agrees with the observations of Hyodo et al., about two orders of magnitude below the prediction of the standard model of Weaver et al.. The difference with respect to the standard (adiabatic) model is the inclusion of radiative cooling, which is still important in such young bubbles. We show that for this type of object the diffuse hard X-ray luminosity is significant compared to that of soft X-rays, contributing as much as 10% of the total luminosity, in contrast with more evolved bubbles where the hard X-ray emission is indeed negligible, being at least four orders of magnitude lower than the soft X-ray emission.

  8. X-ray emission spectroscopic determination of iron in a polyurethane encapsulant curing agent

    International Nuclear Information System (INIS)

    Carter, J.M.; Kling, E.N.

    1979-01-01

    Presented is a procedure for determining the iron content in a polyurethane encapsulant curing agent by x-ray emission spectroscopy. Standards were prepared by adding ferric acetyl acetonate to a curing agent of identical composition to that being analyzed, but containing no iron. Results show that x-ray emission spectroscopy is feasible for determination of iron in the 30 to 50 ppM range. This range could probably be extended by the preparation of additional standards. Precision of the method is approximately 1.2 ppM at the 99 percent confidence level

  9. Calculation of X-ray emission produced by a quasi-monoenergetic electron distribution

    International Nuclear Information System (INIS)

    Fanaei, M.; Sadighi-Bonabi, R.

    2010-01-01

    Complete text of publication follows. By using an intense ultrafast laser interaction with plasma, generation of accelerated relativistic electrons with quasi monoenergetic spectrum has been possible. Analytic expressions for spectra and emission efficiencies of x-rays bremsstrahlung and characteristic line emission produced by a quasi-monoenergetic electron distribution from several targets are investigated. In this work, a Gaussian profile is assumed for the quasi-monoenergetic electron spectrum. The produced x-ray radiations are compared with the previous achieved results for a Maxwellian electron profile. These results and achievements are discussed in detail. Also, the outcomes can be evaluated with the experimental and simulated results.

  10. Study of x-ray emission enhancement via high contrast femtosecond laser interacting with solid foil

    International Nuclear Information System (INIS)

    Chen, Liming; Kando, Masaki; Bulanov, S.V.; Koga, James K.; Tajima, Toshiki; Xu M.H.; Yuan X.H.; Li Y.T.; Dong Q.L.; Zhang J.

    2007-01-01

    We studied the hard x-ray emission and the Kα x-ray conversion efficiency (η K ) produced by 60 fs high contrast frequency doubled Ti: sapphire laser pulse focused on Cu foil target. Cu Kα photon emission obtained with second harmonic laser pulse is more intense than the case of fundamental laser pulse. The Cu η K shows strong dependence on laser nonlinearly skewed pulse shape and reaches the maximum value 4x10 -4 with 100 fs negatively skewed pulse. It shows the electron spectrum shaping contribute to the increase of η K . (author)

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

    International Nuclear Information System (INIS)

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

    2002-01-01

    We describe the first demonstration of a new stable, kHz femtosecond laser-plasma source of hard x-ray continuum and K α 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, K α and K β 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. Weak Hard X-Ray Emission from Two Broad Absorption Line Quasars Observed with NuStar: Compton-Thick Absorption or Intrinsic X-Ray Weakness?

    Science.gov (United States)

    Luo, B.; Brandt, W. N.; Alexander, D. M.; Harrison, F. A.; Stern, D.; Bauer, F. E.; Boggs, S. E.; Christensen, F. E.; Comastri, A.; Craig, W. W..; hide

    2013-01-01

    We present Nuclear Spectroscopic Telescope Array (NuSTAR) hard X-ray observations of two X-ray weak broad absorption line (BAL) quasars, PG 1004+130 (radio loud) and PG 1700+518 (radio quiet). Many BAL quasars appear X-ray weak, probably due to absorption by the shielding gas between the nucleus and the accretion-disk wind. The two targets are among the optically brightest BAL quasars, yet they are known to be significantly X-ray weak at rest-frame 2-10 keV (16-120 times fainter than typical quasars). We would expect to obtain approx. or equal to 400-600 hard X-ray (is greater than or equal to 10 keV) photons with NuSTAR, provided that these photons are not significantly absorbed N(sub H) is less than or equal to 10(exp24) cm(exp-2). However, both BAL quasars are only detected in the softer NuSTAR bands (e.g., 4-20 keV) but not in its harder bands (e.g., 20-30 keV), suggesting that either the shielding gas is highly Compton-thick or the two targets are intrinsically X-ray weak. We constrain the column densities for both to be N(sub H) 7 × 10(exp 24) cm(exp-2) if the weak hard X-ray emission is caused by obscuration from the shielding gas. We discuss a few possibilities for how PG 1004+130 could have Compton-thick shielding gas without strong Fe Ka line emission; dilution from jet-linked X-ray emission is one likely explanation. We also discuss the intrinsic X-ray weakness scenario based on a coronal-quenching model relevant to the shielding gas and disk wind of BAL quasars. Motivated by our NuSTAR results, we perform a Chandra stacking analysis with the Large Bright Quasar Survey BAL quasar sample and place statistical constraints upon the fraction of intrinsically X-ray weak BAL quasars; this fraction is likely 17%-40%.

  13. WEAK HARD X-RAY EMISSION FROM TWO BROAD ABSORPTION LINE QUASARS OBSERVED WITH NuSTAR: COMPTON-THICK ABSORPTION OR INTRINSIC X-RAY WEAKNESS?

    Energy Technology Data Exchange (ETDEWEB)

    Luo, B.; Brandt, W. N. [Department of Astronomy and Astrophysics, 525 Davey Lab, The Pennsylvania State University, University Park, PA 16802 (United States); Alexander, D. M.; Hickox, R. [Department of Physics, Durham University, South Road, Durham DH1 3LE (United Kingdom); Harrison, F. A.; Fuerst, F.; Grefenstette, B. W.; Madsen, K. K. [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Stern, D. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Bauer, F. E. [Departamento de Astronomia y Astrofisica, Pontificia Universidad Catolica de Chile, Casilla 306, Santiago 22 (Chile); Boggs, S. E.; Craig, W. W. [Space Sciences Laboratory, University of California, Berkeley, CA 94720 (United States); Christensen, F. E. [DTU Space-National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby (Denmark); Comastri, A. [INAF-Osservatorio Astronomico di Bologna, Via Ranzani 1, I-40127 Bologna (Italy); Fabian, A. C. [Institute of Astronomy, Madingley Road, Cambridge CB3 0HA (United Kingdom); Farrah, D. [Department of Physics, Virginia Tech, Blacksburg, VA 24061 (United States); Fiore, F. [Osservatorio Astronomico di Roma, via Frascati 33, I-00040 Monteporzio Catone (Italy); Hailey, C. J. [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Matt, G. [Dipartimento di Matematica e Fisica, Universita degli Studi Roma Tre, via della Vasca Navale 84, I-00146 Roma (Italy); Ogle, P. [IPAC, California Institute of Technology, Mail Code 220-6, Pasadena, CA 91125 (United States); and others

    2013-08-01

    We present Nuclear Spectroscopic Telescope Array (NuSTAR) hard X-ray observations of two X-ray weak broad absorption line (BAL) quasars, PG 1004+130 (radio loud) and PG 1700+518 (radio quiet). Many BAL quasars appear X-ray weak, probably due to absorption by the shielding gas between the nucleus and the accretion-disk wind. The two targets are among the optically brightest BAL quasars, yet they are known to be significantly X-ray weak at rest-frame 2-10 keV (16-120 times fainter than typical quasars). We would expect to obtain Almost-Equal-To 400-600 hard X-ray ({approx}> 10 keV) photons with NuSTAR, provided that these photons are not significantly absorbed (N{sub H} {approx}< 10{sup 24} cm{sup -2}). However, both BAL quasars are only detected in the softer NuSTAR bands (e.g., 4-20 keV) but not in its harder bands (e.g., 20-30 keV), suggesting that either the shielding gas is highly Compton-thick or the two targets are intrinsically X-ray weak. We constrain the column densities for both to be N{sub H} Almost-Equal-To 7 Multiplication-Sign 10{sup 24} cm{sup -2} if the weak hard X-ray emission is caused by obscuration from the shielding gas. We discuss a few possibilities for how PG 1004+130 could have Compton-thick shielding gas without strong Fe K{alpha} line emission; dilution from jet-linked X-ray emission is one likely explanation. We also discuss the intrinsic X-ray weakness scenario based on a coronal-quenching model relevant to the shielding gas and disk wind of BAL quasars. Motivated by our NuSTAR results, we perform a Chandra stacking analysis with the Large Bright Quasar Survey BAL quasar sample and place statistical constraints upon the fraction of intrinsically X-ray weak BAL quasars; this fraction is likely 17%-40%.

  14. X-ray astronomy

    International Nuclear Information System (INIS)

    Giacconi, R.; Gursky, H.

    1974-01-01

    This text contains ten chapters and three appendices. Following an introduction, chapters two through five deal with observational techniques, mechanisms for the production of x rays in a cosmic setting, the x-ray sky and solar x-ray emission. Chapters six through ten include compact x-ray sources, supernova remnants, the interstellar medium, extragalactic x-ray sources and the cosmic x-ray background. Interactions of x rays with matter, units and conversion factors and a catalog of x-ray sources comprise the three appendices. (U.S.)

  15. Fast X-ray detection systems based on GaAs diodes grown by LPE

    International Nuclear Information System (INIS)

    Rente, C.; Lauter, J.; Apetz, R.; Lueth, H.

    1996-01-01

    We report on the fabrication and characterization of GaAs based X-ray detectors. The detector structures are grown by liquid phase epitaxy (LPE) and show typical background doping in the order of 10 14 cm -3 (n-type) so that active regions up to 43 μm could be realized. Schottky diodes were processed with active areas up to 1mm 2 . Typical dark current densities are as low as 360pA/mm 2 at 100V. The energy resolution of the detector in combination with a charge sensitive preamplifier was determined to be 1.6keV (FWHM) for x-rays with an energy between 6 and 60keV. The time response of the devices coupled to a fast transimpedance amplifier with a bandwidth of 100MHz was investigated. Single photon detection at room temperature was achieved for X-rays having energies of 14 keV and higher. The measured time resolutions were 600ps (FWHM=1.4ns) and 430ps (FWHM=1.0ns) for X-ray photons of 14.4keV and 21.5keV, respectively. The efficiency of the detector having a 43μm thick depleted layer was determined to be 70% at 14.4 keV and 40% at 21.5keV. These detectors open a new field of X-ray spectroscopy especially for high rate applications and timing measurements at synchrotron radiation facilities

  16. Relations Between FUV Excess and Coronal Soft X-Ray Emission Among Dwarf Stars

    Science.gov (United States)

    Smith, Graeme H.; Hargrave, Mason; Eckholm, Elliot

    2017-11-01

    The far-ultraviolet magnitudes of late-F, G and early-K dwarfs with (B - V) ⩾ 0.50 as measured by the GALEX satellite are shown to correlate with soft X-ray luminosity. This result indicates that line and continuum emission from stellar active regions make significant contributions to the flux in the GALEX FUV band for late-F, G and K dwarfs. By contrast, detection of a correlation between FUV brightness and soft X-ray luminosity among early-F dwarfs requires subtraction of the photospheric component from the FUV flux. The range in (B - V) among F and G dwarfs over which a correlation between uncorrected FUV magnitude and X-ray luminosity is detected coincides with the range in colour over which coronal and chromospheric emission correlates with stellar rotation.

  17. K and L X-ray emission intensities of some radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Verma, H R; Pal, D [Punjabi Univ., Patiala (India). Dept. of Physics

    1985-01-01

    The K and L x-ray emission intensities per 100 disintegrations have been calculated for some radionuclides using the latest adopted data for gamma-ray intensities, electron capture and internal conversion coefficients for the parent nuclides, fluorescence yield values, Coster-Kronig transition probabilities, average total number of primary L shell vacancies produced in the decay of K shell vacancies and emission rates for various shells and subshells for the daughter nuclei. The results are in good agreement with theoretical and experimental values for the K x-ray intensities. There are no experimental results available to compare with the present calculations for the L x-ray intensities; however, there is a marked discrepancy in the L..cap alpha.. and L..beta.. intensities available on the basis of theoretical estimates.

  18. Obtaining attosecond x-ray pulses using a self-amplified spontaneous emission free electron laser

    Directory of Open Access Journals (Sweden)

    A. A. Zholents

    2005-05-01

    Full Text Available We describe a technique for the generation of a solitary attosecond x-ray pulse in a free-electron laser (FEL, via a process of self-amplified spontaneous emission. In this method, electrons experience an energy modulation upon interacting with laser pulses having a duration of a few cycles within single-period wiggler magnets. Two consecutive modulation sections, followed by compression in a dispersive section, are used to obtain a single, subfemtosecond spike in the electron peak current. This region of the electron beam experiences an enhanced growth rate for FEL amplification. After propagation through a long undulator, this current spike emits a ∼250   attosecond x-ray pulse whose intensity dominates the x-ray emission from the rest of the electron bunch.

  19. Einstein X-ray survey of the Pleiades - The dependence of X-ray emission on stellar age

    Science.gov (United States)

    Micela, G.; Sciortino, S.; Serio, S.; Vaiana, G. S.; Bookbinder, J.; Golub, L.; Harnden, F. R., Jr.; Rosner, R.

    1985-01-01

    The data obtained with two pointed observations of 1 deg by 1 deg fields of the Pleiades region have been analyzed, and the results are presented. The maximum-likelihood X-ray luminosity functions for the Pleiades G and K stars in the cluster are derived, and it is shown that, for the G stars, the Pleiades X-ray luminosity function is significantly brighter than the corresponding function for Hyades G dwarf stars. This finding indicates a dependence of X-ray luminosity on stellar age, which is confirmed by comparison of the same data with median X-ray luminosities of pre-main sequence and local disk population dwarf G stars. It is suggested that the significantly larger number of bright X-ray sources associated with G stars than with K stars, the lack of detection of M stars, and the relatively rapid rotation of the Pleiades K stars can be explained in terms of the onset of internal differential rotation near the convective envelope-radidative core interface after the spin-up phase during evolution to the main sequence.

  20. The Sun's X-ray Emission During the Recent Solar Minimum

    Science.gov (United States)

    Sylwester, Janusz; Kowalinski, Mirek; Gburek, Szymon; Siarkowski, Marek; Kuzin, Sergey; Farnik, Frantisek; Reale, Fabio; Phillips, Kenneth J. H.

    2010-02-01

    The Sun recently underwent a period of a remarkable lack of major activity such as large flares and sunspots, without equal since the advent of the space age a half century ago. A widely used measure of solar activity is the amount of solar soft X-ray emission, but until recently this has been below the threshold of the X-ray-monitoring Geostationary Operational Environmental Satellites (GOES). There is thus an urgent need for more sensitive instrumentation to record solar X-ray emission in this range. Anticipating this need, a highly sensitive spectrophotometer called Solar Photometer in X-rays (SphinX) was included in the solar telescope/spectrometer TESIS instrument package on the third spacecraft in Russia's Complex Orbital Observations Near-Earth of Activity of the Sun (CORONAS-PHOTON) program, launched 30 January 2009 into a near-polar orbit. SphinX measures X-rays in a band similar to the GOES longer-wavelength channel.

  1. Soft x-ray emission from gamma-ray bursts observed with ginga

    International Nuclear Information System (INIS)

    Yoshida, Atsumasa; Murakami, Toshio; Itoh, Masayuki

    1989-01-01

    The soft X-ray emission of gamma-ray bursts below 10 keV provides information about size, location, and emission mechanism. The Gamma-ray Burst Detector (GBD) on board Ginga, which consists of a proportional counter and a scintillation detector, covers an energy range down to 1.5 keV with 63 cm 2 effective area. In several of the observed gamma-ray bursts, the intensity of the soft X-ray emission showed a longer decay time of 50 to 100s after the higher energy gamma-ray emission had ended. Although we cannot rule out other models, such as bremsstrahlung and thermal cyclotron types, due to poor statistics, the soft X-ray spectra are consistent with a blackbody of 1 to 2 keV in the late phase of the gamma-ray bursts. This enables us to estimate the size of the blackbody responsible for the X-ray emission. (author)

  2. X-ray continuum and iron K emission line from the radio galaxy 3C 390.3

    Science.gov (United States)

    Inda, M.; Makishima, K.; Kohmura, Y.; Tashiro, M.; Ohashi, T.; Barr, P.; Hayashida, K.; Palumbo, G. G. C.; Trinchieri, G.; Elvis, M.

    1994-01-01

    X-ray properties of the radio galaxy 3C 390.3 were investigated using the European X-ray Observatory Satellite (EXOSAT) and Ginga satellites. Long-term, large-amplitude X-ray intensity changes were detected over a period extending from 1984 through 1991, and high-quality X-ray spectra were obtained especially with Ginga. The X-ray continuum spectra were described with power-law model with photon slope in the range 1.5-1.8, and the slope flattened as the 2-20 keV luminosity decreased by 40%. There was a first detection of the iron emission line from this source at the 90% confidence level. An upper limit was derived on the thermal X-ray component. X-ray emission mechanisms and possible origins of the long-term variation are discussed.

  3. X-ray emission in heavy-ion collisions. Progress report, April 1, 1979-March 31, 1980

    International Nuclear Information System (INIS)

    Watson, R.L.

    1980-04-01

    Recent research in the cyclotron institute and department of chemistry at Texas A and M University on the x-ray emission in heavy-ion collisions is described. Areas covered include: spectra of Ka x-rays from 64 MeV sulfur ions traveling in solids; foil-excited Ka x-ray transitions in few-electron sulfur ions; high-resolution study of the target thickness dependence of x-ray emission from 65 MeV sulfur ions; dynamic screening of highly stripped sulfur ions in solids; Mg Ka x-ray satellites excited by ion bombardment, multiplet structure and dependence on projectile and chemical environment; angular distributions of beam and target Ka x-rays; chemical effects on K x-ray satellites of fluorine compounds; and a non-linear least-squares peak-fitting program employing Voight functions

  4. X-RAY AND RADIO EMISSION FROM TYPE IIn SUPERNOVA SN 2010jl

    Energy Technology Data Exchange (ETDEWEB)

    Chandra, Poonam [National Centre for Radio Astrophysics, Tata Institute of Fundamental Research, Pune University Campus, Pune 411 007 (India); Chevalier, Roger A. [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904-4325 (United States); Chugai, Nikolai [Institute of Astronomy of Russian Academy of Sciences, Pyatnitskaya St. 48, 109017 Moscow (Russian Federation); Fransson, Claes [Oskar Klein Centre, Department of Astronomy, Stockholm University, AlbaNova, SE-106 91 Stockholm (Sweden); Soderberg, Alicia M., E-mail: poonam@ncra.tifr.res.in [Smithsonian Astrophysical Observatory, 60 Garden St., MS-20, Cambridge, MA 02138 (United States)

    2015-09-01

    We present all X-ray and radio observations of the Type IIn supernova SN 2010jl. The X-ray observations cover a period up to day 1500 with Chandra, XMM-Newton, NuSTAR, and Swift-X-ray Telescope (XRT). The Chandra observations after 2012 June, the XMM-Newton observation in 2013 November, and most of the Swift-XRT observations until 2014 December are presented for the first time. All the spectra can be fitted by an absorbed hot thermal model except for Chandra spectra on 2011 October and 2012 June when an additional component is needed. Although the origin of this component is uncertain, it is spatially coincident with the supernova and occurs when there are changes to the supernova spectrum in the energy range close to that of the extra component, indicating that the emission is related to the supernova. The X-ray light curve shows an initial plateau followed by a steep drop starting at day ∼300. We attribute the drop to a decrease in the circumstellar density. The column density to the X-ray emission drops rapidly with time, showing that the absorption is in the vicinity of the supernova. We also present Very Large Array radio observations of SN 2010jl. Radio emission was detected from SN 2010jl from day 570 onwards. The radio light curves and spectra suggest that the radio luminosity was close to its maximum at the first detection. The velocity of the shocked ejecta derived assuming synchrotron self-absorption is much less than that estimated from the optical and X-ray observations, suggesting that free–free absorption dominates.

  5. Positron emission CT and X-ray CT findings in chronic obstructive pulmonary diseases

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Yoshikazu; Murata, Kiyoshi; Ito, Harumi; Senda, Michio; Yonekura, Yoshiharu; Konishi, Junji; Nishimura, Koichi; Izumi, Takahide; Oshima, Shunsaku

    1987-08-01

    Positron emission CT and X-ray CT were performed in fifteen patients with emphysema confirmed SAB and twelve patients with clinical DPB. In patients with emphysema, 20 of 36 areas showed a central pattern and their perfusion scintigrams showed stripe-signs. On the other hand, the patients with DPB showed outer layer progression of the disease.

  6. Optimization of soft x-ray line emission from laser-produced carbon ...

    Indian Academy of Sciences (India)

    Intense XUV soft x-ray emission from laser-produced plasma sources is currently ... absorption edges of oxygen and carbon respectively) is particularly attractive as it permits ... ability of the target element producing intense discrete lines in the water .... ficient due to Pert [17] and dielectronic recombination coefficient due to ...

  7. Cometary X-ray Emission: the View After the First Chandra Observations

    Science.gov (United States)

    Lisse, C. M.

    2002-01-01

    The unexpected discovery of x-ray emission from Comet Hyakutake in March 1996 (Lisse et al. 1996) has produced a number of questions about the physical mechanism producing the radiation. The original detection and subsequent observations (Dennerl et al. 1997, Mumma et al. 1997, Krasnopolsky et al. 1998, Owens et al. 1998, Lisse et al. 1999) have shown that the very soft (best fit thermal bremsstrahlung model kT ~ 0.2 keV) emission is due to an interaction between the solar wind and the comet's atmosphere. Using the results from the 15 comets detected to date in x-rays, we report on the latest results on cometary x-ray emission, including new results from Chandra and XMM. As-observed morphologies, spectra, and light curves will be discussed. Our emphasis will be on understanding the physical mechanism producing the emission, and using this to determine the nature of the cometary coma, the structure of the solar wind in the heliosphere, and the source of the local soft x-ray background. This work has been graciously supported by grants from the NASA Planetary Astronomy and Astrophysical Data Programs.

  8. Correlation between X-ray and high energy gamma-ray emission form Cygnus X-3

    International Nuclear Information System (INIS)

    Weekes, T.C.; Danaher, S.; Fegan, D.J.; Porter, N.A.

    1981-01-01

    In May-June 1980, the 4.8 hour modulated X-ray flux from Cygnus X-3 underwent a significant change in the shape of the light curve; this change correlates with the peak in the high-energy (E > 2 x 10 12 eV) gamma ray emission at the same epoch. (orig.)

  9. X-ray emission from reverse-shocked ejecta in supernova remnants

    Science.gov (United States)

    Cioffi, Denis F.; Mckee, Christopher F.

    1990-01-01

    A simple physical model of the dynamics of a young supernova remnant is used to derive a straightforward kinematical description of the reverse shock. With suitable approximations, formulae can then be developed to give the X-ray emission of the reverse-shocked ejecta. The results are found to agree favorably with observations of SN1006.

  10. The application of proton induced X-ray emission in criminalistics

    International Nuclear Information System (INIS)

    Li Zhenyuan; Xie Shuxian

    1993-01-01

    The determination method of trace elements in high pure gold by proton induced X-ray emission is reported. The target preparation, design of physical experiment, data proceeding and the analysis of gold samples by the internal standard of single-standard are discussed. Using this determination method, the identification of a sample of high pure gold is performed

  11. Interpretation of x-ray emission from lithium-like ions in collisions with helium

    International Nuclear Information System (INIS)

    Armen, G.B.; Aaberg, T.

    1994-01-01

    We consider the continuous x-ray distribution on the low-energy side of the K α line in projectile spectra coincident with single-electron loss in collision of lithium-like ions with helium. We demonstrate that the observed distributions are due to two-photon emission rather than to the radiative Auger effect. (author)

  12. Proton induced X-ray emission analysis of trace elements in human blood serum

    International Nuclear Information System (INIS)

    Cheek, D.B.; Hay, H.J.; Newton, C.S.

    1979-01-01

    Proton induced x-ray emission has been used for quantitative analyses of trace elements in blood serum samples. This work is part of a survey concerned with Zn, Cu, Fe, Cr, Mn and Se in Australian Aboriginal people not receiving optimal diet. Special attention is being directed to Cr because of the high incidence of diabetes mellitus in these people

  13. Proton-induced X-ray emission analysis of Jordanian cigarettes

    International Nuclear Information System (INIS)

    Hallak, A.B.

    1981-01-01

    Proton-induced X-ray emission spectroscopy was applied to determine the concentration of 11 elements in cigaretta tobacco of four brands commercially made in Jordan, and one foreign brand. The results are expressed in absolute amount per cigarette. Cigarette wrapping paper and cigarette smoke were also anlayzed. The significance of some of the elements found in the samples are discussed. (author)

  14. Qualitative analysis of a powdered diamond sample by particle induced X-ray emission (PIXE)

    International Nuclear Information System (INIS)

    Mabida, C.; Annegarn, H.J.; Renan, M.J.; Sellschop, J.P.F.

    The main purpose of this analysis was to determine whether nickel is present in diamond powder as a trace element. Particle induced X-ray emission (PIXE) showed unambiguously that nickel was present. Due to the convenience of PIXE in multielemental analysis, the investigations also include a number of other trace elements in the sample

  15. X-ray Emission from the Radio Jet in 3C 120

    DEFF Research Database (Denmark)

    Harris, D. E.; Hjorth, J.; Sadun, A. C.

    1999-01-01

    We report the discovery of X-ray emission from a radio knot at a projected distance of 25" from the nucleus of the Seyfert galaxy, 3C 120. The data were obtained with the ROSAT High Resolution Imager (HRI). Optical upper limits for the knot preclude a simple power law extension of the radio...

  16. 14th International Conference on Particle Induced X-ray Emission ("PIXE 2015")

    Science.gov (United States)

    Przybyłowicz, Wojciech Józef; Pineda-Vargas, Carlos

    2015-11-01

    This special issue of Nuclear Instruments and Methods in Physics Research B contains the proceedings of the 14th International Conference on Particle Induced X-ray Emission ("PIXE 2015") that was held in Somerset West (South Africa) from 25th February to 3rd March 2015.

  17. The Relationship Between Solar Radio and Hard X-Ray Emission

    Science.gov (United States)

    White, S. M.; Benz, A. O.; Christe, S.; Farnik, F.; Kundu, M. R.; Mann, G.; Ning, Z.; Raulin, J.-P.; Silva-Valio, A. V. R.; Saint-Hilaire, P.; hide

    2011-01-01

    This review discusses the complementary relationship between radio and hard Xray observations of the Sun using primarily results from the era of the Reuven Ramaty High Energy Solar Spectroscopic Imager satellite. A primary focus of joint radio and hard X-ray studies of solar flares uses observations of nonthermal gyrosynchrotron emission at radio wavelengths and bremsstrahlung hard X-rays to study the properties of electrons accelerated in the main flare site, since it is well established that these two emissions show very similar temporal behavior. A quantitative prescription is given for comparing the electron energy distributions derived separately from the two wavelength ranges: this is an important application with the potential for measuring the magnetic field strength in the flaring region, and reveals significant differences between the electrons in different energy ranges. Examples of the use of simultaneous data from the two wavelength ranges to derive physical conditions are then discussed, including the case of microflares, and the comparison of images at radio and hard X-ray wavelengths is presented. There have been puzzling results obtained from observations of solar flares at millimeter and submillimeter wavelengths, and the comparison of these results with corresponding hard X-ray data is presented. Finally, the review discusses the association of hard X-ray releases with radio emission at decimeter and meter wavelengths, which is dominated by plasma emission (at lower frequencies) and electron cyclotron maser emission (at higher frequencies), both coherent emission mechanisms that require small numbers of energetic electrons. These comparisons show broad general associations but detailed correspondence remains more elusive.

  18. Soft X-ray emission from the radio pulsar PSR 0656 + 14

    Science.gov (United States)

    Cordova, F. A.; Middleditch, J.; Hjellming, R. M.; Mason, K. O.

    1989-01-01

    A radio source with a flux density of a few mJy was found in the error region of the soft X-ray source E0656 + 14, and identified as the radio pulsar PSR 0656 + 14. The radio source has a steep, nonthermal spectrum and a high degree of linear (62 percent) and circular (19 percent) polarization. The X-ray spectrum of the pulsar is among the softest sources observed with the Einstein Observatory. The X-ray data taken with the Einstein imaging proportional counter (IPC) permit a range of blackbody temperatures of 3-6 x 10 to the 5th K, and an equivalent column density of hydrogen smaller than 4 x 10 to the 20th/sq cm. If the assumption is made that the X-ray flux is thermal radiation from surface of the neutron star, then the pulsar must be at a distance smaller than 550 pc, consistent with the low dispersion measure of PSR 0656 + 14. The X-ray timing data suggest that the X-ray emission is modulated at the pulsar's 0.385-s spin period with an amplitude of 18 percent + or - 6 percent, and that there is a 0.0002 probability that this is spurious. It was noted that PSR 0656 + 14 is close to the geometric center of a 20-deg diameter soft X-ray emitting ring called the Gemini-Monoceros enhancement. The close distance of the pulsar, together with its relatively young age of 1.1 x 10 to the 5th yr, makes it possible that the ring is a supernova remnant from the explosion of the pulsar's progenitor. A radio source extending over a region 1.2 to 3.3 arcmin south of the pulsar is a candidate for association with the pulsar.

  19. Soft X-ray emission from the radio pulsar PSR 0656 + 14

    International Nuclear Information System (INIS)

    Cordova, F.A.; Middleditch, J.; Hjellming, R.M.; Mason, K.O.

    1989-01-01

    A radio source with a flux density of a few mJy was found in the error region of the soft X-ray source E0656 + 14, and identified as the radio pulsar PSR 0656 + 14. The radio source has a steep, nonthermal spectrum and a high degree of linear (62%) and circular (19%) polarization. The X-ray spectrum of the pulsar is among the softest sources observed with the Einstein Observatory. The X-ray data taken with the Einstein imaging proportional counter (IPC) permit a range of blackbody temperatures of 3-6 x 10 to the 5th K, and an equivalent column density of hydrogen smaller than 4 x 10 to the 20th/sq cm. If the assumption is made that the X-ray flux is thermal radiation from surface of the neutron star, then the pulsar must be at a distance smaller than 550 pc, consistent with the low dispersion measure of PSR 0656 + 14. The X-ray timing data suggest that the X-ray emission is modulated at the pulsar's 0.385-s spin period with an amplitude of 18% + or - 6%, and that there is a 0.0002 probability that this is spurious. It was noted that PSR 0656 + 14 is close to the geometric center of a 20-deg diameter soft X-ray emitting ring called the Gemini-Monoceros enhancement. The close distance of the pulsar, together with its relatively young age of 1.1 x 10 to the 5th yr, makes it possible that the ring is a supernova remnant from the explosion of the pulsar's progenitor. A radio source extending over a region 1.2 to 3.3 arcmin south of the pulsar is a candidate for association with the pulsar. 46 refs

  20. CdTe in photoconductive applications. Fast detector for metrology and X-ray imaging

    International Nuclear Information System (INIS)

    Cuzin, M.

    1991-01-01

    Operating as a photoconductor, the sensitivity and the impulse response of semi-insulating materials greatly depend on the excitation duration compared to electron and hole lifetimes. The requirement of ohmic contact is shortly discussed. Before developing picosecond measurements with integrated autocorrelation system, this paper explains high energy industrial tomographic application with large CdTe detectors (25x15x0.9 mm 3 ). The excitation is typically μs range. X-ray flash radiography, with 10 ns burst, is in an intermediate time domain where excitation is similar to electron life-time. In laser fusion experiment excitation is in the range of 50 ps and we develop photoconductive devices able to study very high speed X-ray emission time behaviour. Thin polycristalline MOCVD CdTe films with picosecond response are suitable to perform optical correlation measurements of single shot pulses with a very large bandwidth (- 50 GHz)

  1. Trace element analysis in liquids by proton induced x-ray emission

    International Nuclear Information System (INIS)

    Deconninck, G.

    Proton induced x-ray emission (PIXE) from liquid has been developed for quantitative and simultaneous analysis of trace elements. Liquid drops and trickles are bombarded at atmospheric pressure, x-rays are detected in a non dispersive Si(Li) solid state detector. Absolute determinations are made by comparison with standard solutions. Detection limits in a 5 minutes run are in the ppm range for a single drop (0.05 ml). The application of this technique to the determination of trace elements in biological liquids is investigated (Cr, Mn, Fe, Co, Ni, Cu, Zn, in plant extracts, haemocyanine, albumins...). (author)

  2. X-ray emission in slow highly charged ion-surface collisions

    International Nuclear Information System (INIS)

    Watanabe, H; Abe, T; Fujita, Y; Sun, J; Takahashi, S; Tona, M; Yoshiyasu, N; Nakamura, N; Sakurai, M; Yamada, C; Ohtani, S

    2007-01-01

    X-rays emitted in the collisions of highly charged ions with a surface have been measured to investigate dissipation schemes of their potential energies. While 8.1% of the potential energy was dissipated in the collisions of He-like I ions with a W surface, 29.1% has been dissipated in the case of He-like Bi ions. The x-ray emissions play significant roles in the dissipation of the potential energies in the interaction of highly charged heavy ions with the surface

  3. Observation of hard X-rays line emission from Her X-1

    Energy Technology Data Exchange (ETDEWEB)

    Polcaro, V.F.; Bazzano, A.; la Padula, C.; Ubertini, P.; Vialetto, G.; Manchanda, R.K.; Damle, S.V.

    1982-04-01

    We present the results of a hard X-ray measurement of the binary source Her X-1, carried out with a balloon borne X-ray telescope consisting of two Multiwire Proportional Counters, having 900 cm/sup 2/ sensitive area each and spectral resolution of 15% and 24% FWHM respectively at 60 keV. The source was observed during the 'Mid-on' state. Our data confirm the previously reported high energy emission line overimposed on the low energy thermal spectrum.

  4. Polarized X-Ray Emission from Magnetized Neutron Stars: Signature of Strong-Field Vacuum Polarization

    Science.gov (United States)

    Lai, Dong; Ho, Wynn C.

    2003-08-01

    In the atmospheric plasma of a strongly magnetized neutron star, vacuum polarization can induce a Mikheyev-Smirnov-Wolfenstein type resonance across which an x-ray photon may (depending on its energy) convert from one mode into the other, with significant changes in opacities and polarizations. We show that this vacuum resonance effect gives rise to a unique energy-dependent polarization signature in the surface emission from neutron stars. The detection of polarized x rays from neutron stars can provide a direct probe of strong-field quantum electrodynamics and constrain the neutron star magnetic field and geometry.

  5. X-ray fluorescence analysis and optical emission spectrometry of an roman mirror from Tomis, Romania

    International Nuclear Information System (INIS)

    Belc, M.; Bogoi, M.; Ionescu, D.; Guita, D.; Caiteanu, S.; Caiteanu, D.

    2000-01-01

    The miscellaneous population of Roman Empire, their diverse cultural tradition, their ability to assimilate the roman civilization spirits, had determined a permanent reassessment superimposed upon the roman contribution. Analysis was undertaken using optical emission spectrometry and non-destructive X-ray fluorescence. X-ray fluorescence analysis is a well-established method and is often used in archaeometry and other work dealing with valuable objects pertaining to the history of art and civilization. Roman mirror analysed has been found not to be made of speculum (a high tin bronze). (authors)

  6. Polarized x-ray emission from magnetized neutron stars: signature of strong-field vacuum polarization.

    Science.gov (United States)

    Lai, Dong; Ho, Wynn C G

    2003-08-15

    In the atmospheric plasma of a strongly magnetized neutron star, vacuum polarization can induce a Mikheyev-Smirnov-Wolfenstein type resonance across which an x-ray photon may (depending on its energy) convert from one mode into the other, with significant changes in opacities and polarizations. We show that this vacuum resonance effect gives rise to a unique energy-dependent polarization signature in the surface emission from neutron stars. The detection of polarized x rays from neutron stars can provide a direct probe of strong-field quantum electrodynamics and constrain the neutron star magnetic field and geometry.

  7. THE SPECTACULAR RADIO-NEAR-IR-X-RAY JET OF 3C 111: THE X-RAY EMISSION MECHANISM AND JET KINEMATICS

    Energy Technology Data Exchange (ETDEWEB)

    Clautice, Devon; Perlman, Eric S. [Department of Physics and Space Sciences, Florida Institute of Technology, 150 W. University Boulevard, Melbourne, FL 32901 (United States); Georganopoulos, Markos [Department of Physics, University of Maryland—Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250 (United States); Lister, Matthew L.; Hogan, Brandon [Department of Physics and Astronomy, Purdue University, 525 Northwestern Avenue, West Lafayette, IN 47907 (United States); Tombesi, Francesco [Department of Astronomy, University of Maryland, College Park, MD 20742-2421 (United States); Cara, Mihai [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Marshall, Herman L. [Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Kazanas, Demos [NASA’s Goddard Space Flight Center, Astrophysics Science Division, Code 663, Greenbelt, MD 20771 (United States)

    2016-08-01

    Relativistic jets are the most energetic manifestation of the active galactic nucleus (AGN) phenomenon. AGN jets are observed from the radio through gamma-rays and carry copious amounts of matter and energy from the sub-parsec central regions out to the kiloparsec and often megaparsec scale galaxy and cluster environs. While most spatially resolved jets are seen in the radio, an increasing number have been discovered to emit in the optical/near-IR and/or X-ray bands. Here we discuss a spectacular example of this class, the 3C 111 jet, housed in one of the nearest, double-lobed FR II radio galaxies known. We discuss new, deep Chandra and Hubble Space Telescope ( HST ) observations that reveal both near-IR and X-ray emission from several components of the 3C 111 jet, as well as both the northern and southern hotspots. Important differences are seen between the morphologies in the radio, X-ray, and near-IR bands. The long (over 100 kpc on each side), straight nature of this jet makes it an excellent prototype for future, deep observations, as it is one of the longest such features seen in the radio, near-IR/optical, and X-ray bands. Several independent lines of evidence, including the X-ray and broadband spectral shape as well as the implied velocity of the approaching hotspot, lead us to strongly disfavor the EC/CMB model and instead favor a two-component synchrotron model to explain the observed X-ray emission for several jet components. Future observations with NuSTAR , HST , and Chandra will allow us to further constrain the emission mechanisms.

  8. X-RAY EMISSION FROM SUPERNOVAE IN DENSE CIRCUMSTELLAR MATTER ENVIRONMENTS: A SEARCH FOR COLLISIONLESS SHOCKS

    International Nuclear Information System (INIS)

    Ofek, E. O.; Gal-Yam, A.; Yaron, O.; Arcavi, I.; Fox, D.; Cenko, S. B.; Filippenko, A. V.; Bloom, J. S.; Sullivan, M.; Gnat, O.; Frail, D. A.; Horesh, A.; Kulkarni, S. R.; Corsi, A.; Quimby, R. M.; Gehrels, N.; Nugent, P. E.; Kasliwal, M. M.; Bildsten, L.; Poznanski, D.

    2013-01-01

    The optical light curve of some supernovae (SNe) may be powered by the outward diffusion of the energy deposited by the explosion shock (the so-called shock breakout) in optically thick (τ ∼> 30) circumstellar matter (CSM). Recently, it was shown that the radiation-mediated and radiation-dominated shock in an optically thick wind must transform into a collisionless shock and can produce hard X-rays. The X-rays are expected to peak at late times, relative to maximum visible light. Here we report on a search, using Swift/XRT and Chandra, for X-ray emission from 28 SNe that belong to classes whose progenitors are suspected to be embedded in dense CSM. Our sample includes 19 Type IIn SNe, one Type Ibn SN, and eight hydrogen-poor superluminous SNe (SLSN-I such as SN 2005ap). Two SNe (SN 2006jc and SN 2010jl) have X-ray properties that are roughly consistent with the expectation for X-rays from a collisionless shock in optically thick CSM. However, the X-ray emission from SN 2006jc can also be explained as originating in an optically thin region. Thus, we propose that the optical light curve of SN 2010jl is powered by shock breakout in CSM. We suggest that two other events (SN 2010al and SN 2011ht) were too X-ray bright during the SN maximum optical light to be explained by the shock-breakout model. We conclude that the light curves of some, but not all, SNe IIn/Ibn are powered by shock breakout in CSM. For the rest of the SNe in our sample, including all of the SLSN-I events, our X-ray limits are not deep enough and were typically obtained too early (i.e., near the SN maximum light) for definitive conclusions about their nature. Late-time X-ray observations are required in order to further test whether these SNe are indeed embedded in dense CSM. We review the conditions required for a shock breakout in a wind profile. We argue that the timescale, relative to maximum light, for the SN to peak in X-rays is a probe of the column density and the density profile above the

  9. CORRELATION OF HARD X-RAY AND WHITE LIGHT EMISSION IN SOLAR FLARES

    Energy Technology Data Exchange (ETDEWEB)

    Kuhar, Matej; Krucker, Säm; Battaglia, Marina; Kleint, Lucia; Casadei, Diego [University of Applied Sciences and Arts Northwestern Switzerland, Bahnhofstrasse 6, 5210 Windisch (Switzerland); Oliveros, Juan Carlos Martinez; Hudson, Hugh S. [Space Sciences Laboratory, University of California, Berkeley, CA 94720-7450 (United States)

    2016-01-01

    A statistical study of the correlation between hard X-ray and white light emission in solar flares is performed in order to search for a link between flare-accelerated electrons and white light formation. We analyze 43 flares spanning GOES classes M and X using observations from the Reuven Ramaty High Energy Solar Spectroscopic Imager and Helioseismic and Magnetic Imager. We calculate X-ray fluxes at 30 keV and white light fluxes at 6173 Å summed over the hard X-ray flare ribbons with an integration time of 45 s around the peak hard-X ray time. We find a good correlation between hard X-ray fluxes and excess white light fluxes, with a highest correlation coefficient of 0.68 for photons with energy of 30 keV. Assuming the thick target model, a similar correlation is found between the deposited power by flare-accelerated electrons and the white light fluxes. The correlation coefficient is found to be largest for energy deposition by electrons above ∼50 keV. At higher electron energies the correlation decreases gradually while a rapid decrease is seen if the energy provided by low-energy electrons is added. This suggests that flare-accelerated electrons of energy ∼50 keV are the main source for white light production.

  10. Dissecting Diffuse X-ray Emission in 30 Doradus with T-ReX

    Science.gov (United States)

    Townsley, Leisa K.; Broos, Patrick

    2017-08-01

    30 Doradus (the Tarantula Nebula) offers us a microscope on starburst astrophysics, having endured 25 Myrs of the birth and death of the most massive stars known. Across 30 Dor's 250-pc extent, stellar winds and supernovae have carved its ISM into an amazing display of arcs, pillars, and bubbles. For over 40 years, we have also known that 30 Dor is a bright X-ray emitter, so its familiar stars and cold ISM structures suffer irradiation by multi-million-degree plasmas. The 2-Ms Chandra X-ray Visionary Project ``The Tarantula -- Revealed by X-rays'' (T-ReX) exploits Chandra's fine spatial resolution and the ACIS-I field of view to study ISM interfaces on 1--10 pc scales across the entire 30 Dor complex. Here we give preliminary results from ongoing analyses of these data, focusing on the diffuse X-ray emission. Massive star winds and cavity supernovae over the millenia have contributed to a broad mix of X-ray-emitting plasmas and absorbing columns, showing that 30 Dor's hot ISM is just as complex and confusing as that seen at colder temperatures.

  11. Current sheath curvature correlation with the neon soft x-ray emission from plasma focus device

    International Nuclear Information System (INIS)

    Zhang, T; Lin, X; Chandra, K A; Tan, T L; Springham, S V; Patran, A; Lee, P; Lee, S; Rawat, R S

    2005-01-01

    The insulator sleeve length is one of the major parameters that can severely affect the neon soft x-ray yield from a plasma focus. The effect of the insulation sleeve length on various characteristic timings of plasma focus discharges and hence the soft x-ray emission characteristics has been investigated using a resistive divider. The pinhole images and laser shadowgraphy are used to explain the observed variation in the average soft x-ray yield (measured using a diode x-ray spectrometer) with variation of the insulator sleeve length. We have found that for a neon filled plasma focus device the change in insulator sleeve length changes the current sheath curvature angle and thus the length of the focused plasma column. The optimized current sheath curvature angle is found to be between 39 0 and 41 0 , at the specific axial position of 6.2-9.3 cm from the cathode support plate, for our 3.3 kJ plasma focus device. A strong dependence of the neon soft x-ray yield on the current sheath curvature angle has thus been reported

  12. Study of the elemental composition of Chenopodium Quinoa Willd by fast neutron activation analysis and X ray fluorescence analysis

    International Nuclear Information System (INIS)

    Soto Moran, R.L.; Szegedi, S.; Llopiz, J.L.

    1996-01-01

    By means of x-ray fluorescence and fast neutron activation analysis the nitrogen content has been determined in samples of roots, stems, leaf, flowers and grains from Quinua (Chenopodium Quinoa Willd), which was previously treated with fertilizer

  13. Characterization of metallic nanoparticles by high-resolution X-ray absorption and X-ray emission spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kuehn, Timna-Josua

    2012-03-15

    In almost all areas of technology, metallic nanoparticles are of interest due to their special thermal, electronic, magnetic and optical properties. Their special properties are mainly due to their small size which implies the relevance of quantum effects as well as the significance of the surface: For 2 nm nanoparticles, the surface-to-volume ratio is already 1:1. However, the identification of surface-to-volume interactions - that are responsible for the new properties - is a difficult task due to the small size that inhibits a lot of 'standard' techniques to be applicable. Here X-ray absorption/emission spectroscopy (XAS/XES) is a favorable tool for the characterization of nanoparticles, independent on size, degree of crystallinity and shape/condition of the surface. Using XAS, a tempered nanosized Co{sub 3}Pt/C catalyst have been investigated. Its outstanding oxygen-reduction reaction (ORR) properties in a fuel cell could be related to a lowered Pt 5d-band center connected to a tightened Pt-Pt bonding distance, leading to a weakening of the oxygen adsorption strength so that the ORR may proceed faster. One drawback remains, however, as the properties found by (standard) XAS are summed up for different chemical environments of the chosen element. Thus, no distinction can be made between, e.g., the pure metal in a nanoparticles' interior and the ligated metal in the outer shells or surface. Here, high-resolution fluorescence-detected XAS (HRFD-XAS) provides additional opportunities as, due to its chemical sensitivity, it leads to site-selective XAS. For a system of 6 nm sized Co nanoparticles, build up of a metallic core surrounded by a protecting shell, that resulted from the 'smooth oxidation' process, this technique of site-selective XAS was proven to be applicable. For the first time, the interior and outer shell of a metallic nanoparticle could be characterized separately. In particular, the Co-hcp phase could be determined for the

  14. Revising the Local Bubble Model due to Solar Wind Charge Exchange X-ray Emission

    Science.gov (United States)

    Shelton, Robin L.

    2009-03-01

    The hot Local Bubble surrounding the solar neighborhood has been primarily studied through observations of its soft X-ray emission. The measurements were obtained by attributing all of the observed local soft X-rays to the bubble. However, mounting evidence shows that the heliosphere also produces diffuse X-rays. The source is solar wind ions that have received an electron from another atom. The presence of this alternate explanation for locally produced diffuse X-rays calls into question the existence and character of the Local Bubble. This article addresses these questions. It reviews the literature on solar wind charge exchange (SWCX) X-ray production, finding that SWCX accounts for roughly half of the observed local 1/4 keV X-rays found at low latitudes. This article also makes predictions for the heliospheric O VI column density and intensity, finding them to be smaller than the observational error bars. Evidence for the continued belief that the Local Bubble contains hot gas includes the remaining local 1/4 keV intensity, the observed local O VI column density, and the need to fill the local region with some sort of plasma. If the true Local Bubble is half as bright as previously thought, then its electron density and thermal pressure are 1/sqrt{2} as great as previously thought, and its energy requirements and emission measure are 1/2 as great as previously thought. These adjustments can be accommodated easily, and, in fact, bring the Local Bubble’s pressure more in line with that of the adjacent material. Suggestions for future work are made.

  15. X-RAY EMISSION FROM THE WOLF-RAYET BUBBLE S 308

    Energy Technology Data Exchange (ETDEWEB)

    Toala, J. A.; Guerrero, M. A. [Instituto de Astrofisica de Andalucia, IAA-CSIC, Glorieta de la Astronomia s/n, 18008 Granada (Spain); Chu, Y.-H.; Gruendl, R. A. [Department of Astronomy, University of Illinois, 1002 West Green Street, Urbana, IL 61801 (United States); Arthur, S. J. [Centro de Radioastronomia y Astrofisica, Universidad Nacional Autonoma de Mexico, Campus Morelia, Apartado Postal 3-72, 58090, Morelia, Michoacan (Mexico); Smith, R. C. [NOAO/CTIO, 950 N. Cherry Avenue, Tucson, AZ 85719 (United States); Snowden, S. L., E-mail: toala@iaa.es [NASA Goddard Space Flight Center, Code 662, Greenbelt, MD 20771 (United States)

    2012-08-10

    The Wolf-Rayet (WR) bubble S 308 around the WR star HD 50896 is one of the only two WR bubbles known to possess X-ray emission. We present XMM-Newton observations of three fields of this WR bubble that, in conjunction with an existing observation of its northwest quadrant, map most of the nebula. The X-ray emission from S 308 displays a limb-brightened morphology, with a central cavity {approx}22' in size and a shell thickness of {approx}8'. This X-ray shell is confined by the optical shell of ionized material. The spectrum is dominated by the He-like triplets of N VI at 0.43 keV and O VII at 0.57 keV, and declines toward high energies, with a faint tail up to 1 keV. This spectrum can be described by a two-temperature optically thin plasma emission model (T{sub 1} {approx} 1.1 Multiplication-Sign 10{sup 6} K, T{sub 2} {approx} 13 Multiplication-Sign 10{sup 6} K), with a total X-ray luminosity {approx}2 Multiplication-Sign 10{sup 33} erg s{sup -1} at the assumed distance of 1.5 kpc.

  16. X-RAY EMISSION FROM THE WOLF-RAYET BUBBLE S 308

    International Nuclear Information System (INIS)

    Toalá, J. A.; Guerrero, M. A.; Chu, Y.-H.; Gruendl, R. A.; Arthur, S. J.; Smith, R. C.; Snowden, S. L.

    2012-01-01

    The Wolf-Rayet (WR) bubble S 308 around the WR star HD 50896 is one of the only two WR bubbles known to possess X-ray emission. We present XMM-Newton observations of three fields of this WR bubble that, in conjunction with an existing observation of its northwest quadrant, map most of the nebula. The X-ray emission from S 308 displays a limb-brightened morphology, with a central cavity ∼22' in size and a shell thickness of ∼8'. This X-ray shell is confined by the optical shell of ionized material. The spectrum is dominated by the He-like triplets of N VI at 0.43 keV and O VII at 0.57 keV, and declines toward high energies, with a faint tail up to 1 keV. This spectrum can be described by a two-temperature optically thin plasma emission model (T 1 ∼ 1.1 × 10 6 K, T 2 ∼ 13 × 10 6 K), with a total X-ray luminosity ∼2 × 10 33 erg s –1 at the assumed distance of 1.5 kpc.

  17. Exploring the Diffuse X-ray Emission of Supernova Remnant Kesteven 69 with XMM-Newton

    Directory of Open Access Journals (Sweden)

    Kyoung-Ae Seo

    2013-06-01

    Full Text Available We have investigated the X-ray emission from the shock-heated plasma of the Galactic supernova remnant Kesteven 69 with XMM-Newton. Assuming the plasma is at collisional ionization equilibrium, a plasma temperature and a column absorption are found to be kT ~ 0.62 keV and NH ~ 2.85 ×1022 cm-2 respectively by imaging spectroscopy. Together with the deduced emission measure, we place constraints on its Sedov parameters.

  18. Analysis of the electronic structure of human hemoglobin from soft X-ray emission

    International Nuclear Information System (INIS)

    Soldatov, A.V.; Kravtsova, A.N.; Fedorovich, E.N.; Ankudinov, A.; Moewes, A.; Kurmaev, E.Z.

    2005-01-01

    We present X-ray emission spectra (XES) of human hemoglobin excited near the iron L 2,3 threshold and the nitrogen and carbon K-edges. The experiment is compared with our calculations of the corresponding spectra and gives good agreement. We find that the Fe L 3 emission is affected by the nearest nitrogen atoms located in the heme plane around the central iron atom. The distribution of the partial electronic densities of states of hemoglobin is determined

  19. The orbital period in the supergiant fast X-ray transient IGR J16465--4507

    OpenAIRE

    Clark, D. J.; Sguera, V.; Bird, A. J; McBride, V. A.; Hill, A. B.; Scaringi, S.; Drave, S.; Bazzano, A.; Dean, A. J

    2010-01-01

    Timing analysis of the INTEGRAL-IBIS and Swift-BAT light curves of the Supergiant Fast X-ray Transient (SFXT) IGR J16465-4507 has identified a period of 30.32+/-0.02 days which we interpret as the orbital period of the binary system. In addition 11 outbursts (9 of which are previously unpublished) have been found between MJD 52652 to MJD 54764, all of which occur close to the region of the orbit we regard as periastron. From the reported flux outbursts, we found a dynamical range in the inter...

  20. Fast neutron activation analysis and radioisotope X-ray fluorescence study on KALEWA and NAMMA coal

    International Nuclear Information System (INIS)

    Naing-Win

    1981-07-01

    Kalewa coal was studied with Fast Neutron Activation Analysis (FNAA) technique, employing KAMAN A-710 neutron generator and HP(Ge) detector coupled to ''Canberra'' series 30 MCA. Sequential irradiation and dual aluminium foil monitoring method was employed. Simultaneous multielement analysis was carried out. Namma Coal was studied with radioisotope X-ray Fluorescence (XRF) technique, employing Co-57 exciter source and HP(Ge) detector coupled to ''Canberra'' series 40 MCA. In both FNAA and XRF study, the results obtained were compared to that obtained with Atomic Absorption Spectrophotometry (AAS) technique. Finally, the results were reviewed together with those obtained from similar work on coal with FNAA and XRF techniques. (author)

  1. Fast neutron activation analysis and radioisotope X-ray fluorescence study on KALEWA and NAMMA coal

    Energy Technology Data Exchange (ETDEWEB)

    Naing-Win, [Arts and Science University, Yangon (Myanmar)

    1981-07-01

    Kalewa coal was studied with Fast Neutron Activation Analysis (FNAA) technique, employing KAMAN A-710 neutron generator and HP(Ge) detector coupled to ``Canberra`` series 30 MCA. Sequential irradiation and dual aluminium foil monitoring method was employed. Simultaneous multielement analysis was carried out. Namma Coal was studied with radioisotope X-ray Fluorescence (XRF) technique, employing Co-57 exciter source and HP(Ge) detector coupled to ``Canberra`` series 40 MCA. In both FNAA and XRF study, the results obtained were compared to that obtained with Atomic Absorption Spectrophotometry (AAS) technique. Finally, the results were reviewed together with those obtained from similar work on coal with FNAA and XRF techniques. (author).

  2. Fast helicity switching of x-ray circular polarization at beamline P09 at PETRA III

    Energy Technology Data Exchange (ETDEWEB)

    Strempfer, J., E-mail: Joerg.Strempfer@desy.de; Mardegan, J. R. L.; Francoual, S.; Veiga, L. S. I.; Spitzbart, T.; Zink, H. [Deutsches Elektronen Synchrotron (DESY), Notkestrasse 85, 22603 Hamburg (Germany); Bouchenoire, L. [XMaS, ESRF, 6 rue Jules Horowitz, BP220, Grenoble 38043 (France); Department of Physics, University of Liverpool, Liverpool, L69 7ZE (United Kingdom)

    2016-07-27

    At the resonant scattering and diffraction beamline P09 at PETRA III/DESY, polarization manipulation in the X-ray energy range 3-13 keV is possible using wave-plates. Recently, fast flipping of circular polarization helicity using the Raspberry Pi controlled FPGA (PiLC) device developed at DESY and dedicated piezo-electric flippers has been commissioned. Functionality of the PiLC for XMCD and first XMCD measurements at the Fe K-and Dy-L{sub 3} absorption edges are presented.

  3. Characterizing the X-ray Emission in Small Magellanic Cloud Supernova Remnants

    Science.gov (United States)

    Man, Nicole; Auchettl, Katie; Lopez, Laura

    2018-01-01

    The Small Magellanic Cloud is a close, metal-poor galaxy with active star formation, and it has a diverse population of 24 supernova remnants (SNRs) that have been identified at several wavelengths. Past work has characterized the X-ray emission in these sources separately and aimed to constrain their explosive origins from observations with Chandra and XMM-Newton. Three SNRs have possible evidence for Type Ia explosions based on strong Fe-L emission in their X-ray spectra, although the environments and intermediate-mass element abundances are more consistent with those of core-collapse SNe. In this poster, we analyze the archival Chandra and XMM-Newton observations of the SMC SNR sample, and we model the sources' X-ray spectra in a systematic way to derive the plasma properties and to constrain the nature of the explosions. In one SNR, we note the presence of an X-ray binary near the source's geometric center, suggesting the compact object was produced in the SN explosion. As one of only three SNRs known in the Local Group to host a binary system, this source is worthy of follow-up investigations to probe explosions of massive stars in binary systems.

  4. An optimised set-up for total reflection particle induced X-ray emission

    International Nuclear Information System (INIS)

    Kan, J.A. van; Vis, R.D.

    1997-01-01

    MeV proton beams at small angles of incidence (0-35 mrad) are used to analyse trace elements on flat surfaces such as Si wafers or quartz substrates. In these experiments, the particle induced X-ray emission (PIXE) signal is used in a new optimized set-up. This set-up is constructed in such a way that the X-ray detector can reach very large solid angles, larger than 1 sr. Use of these large detector solid angles, combined with the reduction of bremsstrahlung background, affords limits of detection (LOD) of the order of 10 10 at cm -2 using total reflection particle induced X-ray emission (TPIXE). The LODs from earlier TPIXE measurements in a non-optimized set-up are used to estimate LODs in the new TPIXE set-up. Si wafers with low surface concentrations of V, Ni, Cu and Ag are used as standards to calibrate the LODs found with this set-up. The metal concentrations are determined by total reflection X-ray fluorescence (TXRF). The TPIXE measurements are compared with TXRF measurements on the same wafers. (Author)

  5. Time response of fast-gated microchannel plates used as x-ray detectors

    International Nuclear Information System (INIS)

    Turner, R.E.; Bell, P.; Hanks, R.; Kilkenny, J.D.; Landen, N.; Power, G.; Wiedwald, J.; Meier, M.

    1990-01-01

    We report measurements of the time response of fast-gated, micro- channel plate (MCP) detectors, using a <10 ps pulsewidth ultra-violet laser and an electronic sampling system to measure time resolutions to better than 25 ps. The results show that framing times of less than 100 ps are attainable with high gain. The data is compared to a Monte Carlo calculation, which shows good agreement. We also measured the relative sensitivity as a function of DC bias, and saturation effects for large signal inputs. In part B, we briefly describe an electrical ''time-of-flight'' technique, which we have used to measure the response time of a fast-gated microchannel plate (MCP). Thinner MCP's than previously used have been tested, and, as expected, show fast gating times and smaller electron multiplication. A preliminary design for an x-ray pinhole camera, using a thin MCP, is presented. 7 refs., 6 figs

  6. Forge: a short pulse x-ray diagnostic development facility

    International Nuclear Information System (INIS)

    Stradling, G.L.; Hurry, T.R.; Denbow, E.R.; Selph, M.M.; Ameduri, F.P.

    1985-01-01

    A new short pulse x-ray calibration facility has been brought on line at Los Alamos. This facility is being used for the development, testing and calibration of fast x-ray diagnostic systems. The x-ray source consists of a moderate size, sub-nanosecond laser focused at high intensity on an appropriate target material to generate short pulses of x-ray emission from the resulting plasma. Dynamic performance parameters of fast x-ray diagnostic instruments, such as x-ray streak cameras, can be conveniently measured using this facility

  7. Soft X-ray synchrotron radiation investigations of actinide materials systems utilizing X-ray emission spectroscopy and resonant inelastic X-ray scattering

    International Nuclear Information System (INIS)

    Shuh, D.K.; Butorin, S.M.; Guo, J.-H.; Nordgren, J.

    2004-01-01

    Synchrotron radiation (SR) methods have been utilized with increasing frequency over the past several years to study topics in actinide science, ranging from those of a fundamental nature to those that address a specifically-targeted technical need. In particular, the emergence of microspectroscopic and fluorescence-based techniques have permitted investigations of actinide materials at sources of soft x-ray SR. Spectroscopic techniques with fluorescence-based detection are useful for actinide investigations since they are sensitive to small amounts of material and the information sampling depth may be varied. These characteristics also serve to simplify both sample preparation and safety considerations. Examples of investigations using these fluorescence techniques will be described along with their results, as well as the prospects for future investigations utilizing these methodologies

  8. Where is the X-ray emission coming from in RT Cru Symbiotic System?

    Science.gov (United States)

    Karovska, Margarita

    2014-11-01

    RT Cru is a member of a new sub-class of symbiotic interacting binaries with copious hard X-ray emission. It consists of a high-mass WD (>1.3 Ms) accreting from the wind of an M giant, and it is an important system to study in order to constrain precursor conditions for asymmetric PN and SN Ia. The Chandra HRC-I observation (Dec 2012), and an overlapping Swift observation, detected intermittent soft X-ray flaring, and we find evidence for a significant soft component in the spectrum. The flaring could be a consequence of clumped absorption columns moving in and out of the line of sight, or the variations could be due to changes at the accretion boundary layer. Further observations are needed to determine the origin of the soft emission and its relation to the hard emission.

  9. Resonant x-ray emission from gas-phase TiCl{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Hague, C.F.; Tronc, M. [Universite Pierre et Marie Curie, Paris (France); De Groot, F. [Univ. of Groningen (Netherlands)] [and others

    1997-04-01

    Resonant x-ray emission spectroscopy (RXES) has proved to be a powerful tool for studying the electronic structure of condensed matter. Over the past few years it has been used mainly for studying the valence bands of solids and condensed molecules. Very recently the advent of high brightness photon beams provided by third generation synchrotron radiation source undulators, associated with efficient x-ray emission spectrometers has made it possible to perform experiments on free diatomic molecular systems. RXE spectra of free molecules are of prime importance to gain insight into their electronic structure and bonding as they reflect the symmetry of orbitals engaged in the two-electron, two-step process with the l = 0, {+-}2 parity-conserving selection rule, and are free from solid state effects which can introduce difficulties in the interpretation. They provide information (more so than XAS) on the core excited states, and, when performed at fixed incident photon energy as a function of the emitted photon energy, on the electronic excitation (charge transfer, multiplet states). Moreover the anisotropy of the angular distribution of resonant x-ray emission affects the relative intensity of the emission peaks and provides information concerning the symmetries of final states. This is a preliminary report on what are the first RXE spectra of a 3d transition metal complex in the gas phase. The experiment concerns the Ti 3d {yields}2p emission spectrum of TiCl{sub 4} over the 450 to 470 eV region.

  10. Resonant x-ray emission from gas-phase TiCl4

    International Nuclear Information System (INIS)

    Hague, C.F.; Tronc, M.; De Groot, F.

    1997-01-01

    Resonant x-ray emission spectroscopy (RXES) has proved to be a powerful tool for studying the electronic structure of condensed matter. Over the past few years it has been used mainly for studying the valence bands of solids and condensed molecules. Very recently the advent of high brightness photon beams provided by third generation synchrotron radiation source undulators, associated with efficient x-ray emission spectrometers has made it possible to perform experiments on free diatomic molecular systems. RXE spectra of free molecules are of prime importance to gain insight into their electronic structure and bonding as they reflect the symmetry of orbitals engaged in the two-electron, two-step process with the l = 0, ±2 parity-conserving selection rule, and are free from solid state effects which can introduce difficulties in the interpretation. They provide information (more so than XAS) on the core excited states, and, when performed at fixed incident photon energy as a function of the emitted photon energy, on the electronic excitation (charge transfer, multiplet states). Moreover the anisotropy of the angular distribution of resonant x-ray emission affects the relative intensity of the emission peaks and provides information concerning the symmetries of final states. This is a preliminary report on what are the first RXE spectra of a 3d transition metal complex in the gas phase. The experiment concerns the Ti 3d →2p emission spectrum of TiCl 4 over the 450 to 470 eV region

  11. Chandra Observations of Extended X-Ray Emission in ARP 220

    Science.gov (United States)

    McDowell, J. C.; Clements, D. L.; Lamb, S. A.; Shaked, S.; Hearn, N. C.; Colina, L.; Mundell, C.; Borne, K.; Baker, A. C.; Arribas, S.

    2003-01-01

    We resolve the extended X-ray emission from the prototypical ultraluminous infrared galaxy Arp 220. Extended, faint, edge-brightened, soft X-ray lobes outside the optical galaxy are observed to a distance of 1CL 15 kpc on each side of the nuclear region. Bright plumes inside the optical isophotes coincide with the optical line emission and extend 1 1 kpc from end to end across the nucleus. The data for the plumes cannot be fitted by a single-temperature plasma and display a range of temperatures from 0.2 to 1 keV. The plumes emerge from bright, diffuse circumnuclear emission in the inner 3 kpc centered on the Ha peak, which is displaced from the radio nuclei. There is a close morphological correspondence between the Ha and soft X-ray emission on all spatial scales. We interpret the plumes as a starburst-driven superwind and discuss two interpretations of the emission from the lobes in the context of simulations of the merger dynamics of Arp 220.

  12. Application of the alanine detector to gamma-ray, X-ray and fast neutron dosimetry

    International Nuclear Information System (INIS)

    Waligorski, M.P.R.; Hansen, J.W.; Byrski, E.

    1987-01-01

    A dosimeter based on alanine has been developed at the INP in Krakow and at Risoe National Laboratory. Due to its near tissue-equivalence and stability of signal, measured using ESR spectrometry at room temperature, this free-radical amino-acid dosimetric system is particularly suitable for measuring X-ray, gamma-ray and fast neutron doses in the range 10-10 5 Gy. The relative effectiveness (with respect to 60 Co γ-rays) of the alanine dosimeter to 250 kVp X-rays and to cyclotron-produced fast neutrons (mean neutron energy 5.6 MeV) is measured to be 0.76± 0.06 and 0.60±0.05, respectively. The suitability of the alanine dosimeter for intercomparison gamma-ray dosimetry is also shown. The estimated absolute difference between 60 Co dosimetry at Risoe National Laboratory and at the Centre of Oncology in Krakow is about 5%, somewhat more than the experimental uncertainty. These results are based on ESR measurements performed in Krakow on about 25% of the exposed detectors. 28 refs., 2 figs., 3 tabs. (author)

  13. A SUZAKU SEARCH FOR NONTHERMAL EMISSION AT HARD X-RAY ENERGIES IN THE COMA CLUSTER

    International Nuclear Information System (INIS)

    Wik, Daniel R.; Sarazin, Craig L.; Finoguenov, Alexis; Matsushita, Kyoko; Nakazawa, Kazuhiro; Clarke, Tracy E.

    2009-01-01

    The brightest cluster radio halo known resides in the Coma cluster of galaxies. The relativistic electrons producing this diffuse synchrotron emission should also produce inverse Compton emission that becomes competitive with thermal emission from the intracluster medium (ICM) at hard X-ray energies. Thus far, claimed detections of this emission in Coma are controversial. We present a Suzaku HXD-PIN observation of the Coma cluster in order to nail down its nonthermal hard X-ray content. The contribution of thermal emission to the HXD-PIN spectrum is constrained by simultaneously fitting thermal and nonthermal models to it and a spatially equivalent spectrum derived from an XMM-Newton mosaic of the Coma field. We fail to find statistically significant evidence for nonthermal emission in the spectra which are better described by only a single- or multitemperature model for the ICM. Including systematic uncertainties, we derive a 90% upper limit on the flux of nonthermal emission of 6.0 x 10 -12 erg s -1 cm -2 (20-80 keV, for Γ = 2.0), which implies a lower limit on the cluster-averaged magnetic field of B>0.15 μG. Our flux upper limit is 2.5 times lower than the detected nonthermal flux from RXTE and BeppoSAX. However, if the nonthermal hard X-ray emission in Coma is more spatially extended than the observed radio halo, the Suzaku HXD-PIN may miss some fraction of the emission. A detailed investigation indicates that ∼50%-67% of the emission might go undetected, which could make our limit consistent with that of Rephaeli and Gruber and Fusco-Femiano et al. The thermal interpretation of the hard Coma spectrum is consistent with recent analyses of INTEGRAL and Swift data.

  14. Proton-Induced X-Ray Emission Analysis of Crematorium Emissions

    Science.gov (United States)

    Ali, Salina; Nadareski, Benjamin; Yoskowitz, Joshua; Labrake, Scott; Vineyard, Michael

    2014-09-01

    There has been considerable debate in recent years about possible mercury emissions from crematoria due to amalgam tooth restorations. We have performed a proton-induced X-ray emission (PIXE) analysis of aerosol and soil samples taken near the Vale Cemetery Crematorium in Schenectady, NY, to address this concern. The aerosol samples were collected on the roof of the crematorium using a nine-stage, cascade impactor that separates the particulate matter by aerodynamic diameter and deposits it onto thin Kapton foils. The soil samples were collected at several different distances from the crematorium and compressed into pellets with a hydraulic press. The Kapton foils containing the aerosol samples and the soil pellets were bombarded with 2.2-MeV protons from the 1.1-MV tandem Pelletron accelerator in the Union College Ion-Beam Analysis Laboratory. We measured significant concentrations of sulfur, phosphorus, potassium, calcium, and iron, but essentially no mercury in the aerosol samples. The lower limit of detection for airborne mercury in this experiment was approximately 0.2 ng / m3. The PIXE analysis of the soil samples showed the presence of elements commonly found in soil (Si, K, Ca, Ti, Mn, Fe), but no trace of mercury. There has been considerable debate in recent years about possible mercury emissions from crematoria due to amalgam tooth restorations. We have performed a proton-induced X-ray emission (PIXE) analysis of aerosol and soil samples taken near the Vale Cemetery Crematorium in Schenectady, NY, to address this concern. The aerosol samples were collected on the roof of the crematorium using a nine-stage, cascade impactor that separates the particulate matter by aerodynamic diameter and deposits it onto thin Kapton foils. The soil samples were collected at several different distances from the crematorium and compressed into pellets with a hydraulic press. The Kapton foils containing the aerosol samples and the soil pellets were bombarded with 2.2-Me

  15. A Multiwavelength Exploration of the Grand Design Spiral M83: Diffuse X-ray Emission

    Science.gov (United States)

    Kuntz, K. D.; Long, K. S.; Blair, W. P.; Plucinsky, P. P.; Soria, R.; Winkler, P. F.

    2013-01-01

    We have obtained a series of deep X-ray images of the nearby galaxy M83, with a total exposure 729 ksec with the Chandra ACIS-S array. Since the bulk of the X-ray emitting disk falls within the BI chip, these observations allow a detailed study of the soft diffuse emission in the disk. Most of the diffuse emission is related to star-formation regions and must be powered by supernovae and stellar winds, though the amount of emission due to identifiable SNR is only a few percent. The relation between the spectral shape and surface brightness that was seen in M101 suggests that the properties of the X-ray emission in spiral disks are shaped by the local hot gas production rate (traced by the local star-formation rate) or the disk mid-plane pressure, but it is unclear which physical mechanism dominates. To illuminate this problem, we will compare M83 with the previous Chandra studies of M101 and M33.

  16. THE XMM-Newton and integral observations of the Supergiant Fast X-Ray Transient IGR J16328-4726

    OpenAIRE

    Fiocchi, M.; Bazzano, A.; Natalucci, L.; Ubertini, P.; Sguera, V.; Bird, A. J.; Boon, C.M.; Persi, P.; Piro, L.

    2016-01-01

    The accretion mechanism producing the short flares observed from the Supergiant Fast X-ray Transients (SFXT) is still highly debated and forms a major part in our attempts to place these X-ray binaries in the wider context of the High Mass X-ray Binaries. We report on a 216 ks INTEGRAL observation of the SFXT IGR J16328-4726 (2014 August 24–27) simultaneous with two fixed-time observations with XMM-Newton (33 and 20 ks) performed around the putative periastron passage, in order to investigate...

  17. Hard X-Ray Emission from Partially Occulted Solar Flares: RHESSI Observations in Two Solar Cycles

    Energy Technology Data Exchange (ETDEWEB)

    Effenberger, Frederic; Costa, Fatima Rubio da; Petrosian, Vahé [Department of Physics and KIPAC, Stanford University, Stanford, CA 94305 (United States); Oka, Mitsuo; Saint-Hilaire, Pascal; Krucker, Säm [Space Sciences Laboratory, University of California, Berkeley, CA 94720-7450 (United States); Liu, Wei [Bay Area Environmental Research Institute, 625 2nd Street, Suite 209, Petaluma, CA 94952 (United States); Glesener, Lindsay, E-mail: feffen@stanford.edu, E-mail: frubio@stanford.edu [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States)

    2017-02-01

    Flares close to the solar limb, where the footpoints are occulted, can reveal the spectrum and structure of the coronal looptop source in X-rays. We aim at studying the properties of the corresponding energetic electrons near their acceleration site, without footpoint contamination. To this end, a statistical study of partially occulted flares observed with Reuven Ramaty High-Energy Solar Spectroscopic Imager is presented here, covering a large part of solar cycles 23 and 24. We perform detailed spectra, imaging, and light curve analyses for 116 flares and include contextual observations from SDO and STEREO when available, providing further insights into flare emission that were previously not accessible. We find that most spectra are fitted well with a thermal component plus a broken power-law, non-thermal component. A thin-target kappa distribution model gives satisfactory fits after the addition of a thermal component. X-ray imaging reveals small spatial separation between the thermal and non-thermal components, except for a few flares with a richer coronal source structure. A comprehensive light curve analysis shows a very good correlation between the derivative of the soft X-ray flux (from GOES ) and the hard X-rays for a substantial number of flares, indicative of the Neupert effect. The results confirm that non-thermal particles are accelerated in the corona and estimated timescales support the validity of a thin-target scenario with similar magnitudes of thermal and non-thermal energy fluxes.

  18. X-ray Emission Spectrum of Liquid Ethanol: Origin of Split Peaks.

    Science.gov (United States)

    Takahashi, Osamu; Ljungberg, Mathias P; Pettersson, Lars G M

    2017-12-14

    The X-ray emission spectrum of liquid ethanol was calculated using density functional theory and a semiclassical approximation to the Kramers-Heisenberg formula including core-hole-induced dynamics. Our spectrum agrees well with the experimental spectrum. We found that the intensity ratio between the two peaks at 526 and 527 eV assigned as 10a' and 3a″ depends not only on the hydrogen bonding network around the target molecule but also on the intramolecular conformation. This effect is absent in liquid methanol and demonstrates the high sensitivity of X-ray emission to molecular structure. The dependence of spectral features on hydrogen-bonding as well as on dynamical effects following core excitation are also discussed.

  19. Environmental aspects of ion-induced x-ray emission by infinitely thick targets

    International Nuclear Information System (INIS)

    Van Rinsvelt, H.A.; Dunnam, F.E.; Russell, J.P.; Bolch, W.E.

    1974-01-01

    Elemental analysis through proton and alpha particle induced x-ray emission by infinitely thick samples of environmental interest was found to be feasible. A quantization technique using internal standards and the optimization of the beam energy for optimal sensitivity were investigated. The average limit of detection ranges from about 0.1 ppM for calcium to 1 ppM for strontium

  20. Bulk band gaps in divalent hexaborides: A soft x-ray emission study

    International Nuclear Information System (INIS)

    Denlinger, Jonathan D.; Gweon, Gey-Hong; Allen, James W.; Bianchi, Andrea D.; Fisk, Zachary

    2001-01-01

    Boron K-edge soft x-ray emission and absorption are used to address the fundamental question of whether divalent hexaborides are intrinsic semimetals or defect-doped bandgap insulators. These bulk sensitive measurements, complementary and consistent with surface-sensitive angle-resolved photoemission experiments, confirm the existence of a bulk band gap and the location of the chemical potential at the bottom of the conduction band

  1. X-ray emission spectroscopy of well-characterised non-LTE plasmas

    International Nuclear Information System (INIS)

    Bourgaux, A C; Bastiani-Ceccotti, S; Audebert, P; Marquès, J R; Vassura, L; Vinci, T; Jacquemot, S; Dorchies, F; Leguay, P M; Chung, H K; Bowen, C; Dervieux, V; Renaudin, P; Silvert, V

    2016-01-01

    This paper will present an experimental platform developed on LULI2000 to measure x-ray emission of non-LTE plasmas in well-defined hydrodynamic conditions thanks to implementation of a whole set of diagnostics, including time-resolved electronic and ionic Thomson scattering and self-optical pyrometry. K-, L- and M-shell spectra will be presented and the methodology, that has been developed to analyze them, discussed. (paper)

  2. Method and multichannel equipment for chemical analysis by X-ray emission

    International Nuclear Information System (INIS)

    Bacso, J.; Horkay, Gy.; Kalinka, G.; Kertesz, Zs.; Kiss Varga, M.; Lakatos, T.; Mathe, Gy.; Paal, A.; Sulik, B.

    1978-01-01

    In the patent a simple method and an apparatus are described for chemical analysis based on X-ray emission generated by irradiation. The concentrations of pre-selected elements can be determined easily by this method using an equipment containing microprocessor. The number of channels and the elements to be determined can be modified by a simple change in the program. (Sz.J.)

  3. Particle induced X-ray emission for quantitative trace-element analysis using the Eindhoven cyclotron

    International Nuclear Information System (INIS)

    Kivits, H.

    1980-01-01

    Development of a multi-elemental trace analysis technique using PIXE (Particle Induced X-ray Emission), was started almost five years ago at the Eindhoven University of Technology, in the Cyclotron Applications Group of the Physics Department. The aim of the work presented is to improve the quantitative aspects of trace-element analysis with PIXE, as well as versatility, speed and simplicity. (Auth.)

  4. Portable pulse X-ray micro and nanosecond range apparatus for studying fast-going processes in opaque media

    International Nuclear Information System (INIS)

    Goganov, D.A.; Komyak, N.I.; Pelix, E.A.

    Pulse X-radiography (X-ray flash duration in the order of 10 -6 -10 -9 sec) is the principal method for studying fast-going processes in opaque media by serial and parallel radiographic imaging. Description is given and main features are outlined of pulse X-ray apparatus IRA-4b, 5b, 6b producing X-radiation flashes from 0.3 μsec to 10-20 nsec in duration

  5. OBSERVATIONS OF X-RAY OSCILLATIONS IN ξ BOO: EVIDENCE OF A FAST-KINK MODE IN THE STELLAR LOOPS

    International Nuclear Information System (INIS)

    Pandey, J. C.; Srivastava, A. K.

    2009-01-01

    We report the observations of X-ray oscillations during the flare in a cool active star ξ Boo for the first time. ξ Boo was observed by EPIC/MOS of the XMM-Newton satellite. The X-ray light curve is investigated with wavelet and periodogram analyses. Both analyses clearly show oscillations of the period of ∼1019 s. We interpret these oscillations as a fundamental fast-kink mode of magnetoacoustic waves.

  6. Fast optical and X-ray variability in the UCXB 4U0614+09

    Science.gov (United States)

    Hakala, P. J.; Charles, P. A.; Muhli, P.

    2011-09-01

    We present results from several years of fast optical photometry of 4U0614+091 (V1055 Orionis), a candidate ultracompact X-ray binary most likely consisting of a neutron star and a degenerate secondary. We find evidence for strong accretion-driven variability at all epochs, which manifests itself as red noise. This flickering produces transient peaks in the observed power spectrum in the 15-65 min period range. Only in one of our 12 optical data sets can we see evidence for a period that cannot be reproduced using the red noise model. This period of 51 min coincides with the strongest period detected by Shahbaz et al. and can thus be taken as the prime candidate for the orbital period of the system. Furthermore, we find some tentative evidence for the X-ray versus optical flux anticorrelation discovered by Machin et al. using our data together with the all-sky X-ray monitoring data from RXTE/All Sky Monitor. We propose that the complex time series behaviour of 4U0614+09 is a result of drastic changes in the accretion disc geometry/structure on time-scales from hours to days. Finally, we want to draw attention to the interpretation of moderately strong peaks in the power spectra of especially accreting sources. Many of such 'periods' can probably be attributed to the presence of red noise (i.e. correlated events) in the data. Based on observations made with the Nordic Optical Telescope, operated on the island of La Palma jointly by Denmark, Finland, Iceland, Norway and Sweden, in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofisica de Canarias. Uses results provided by the ASM/RXTE teams at MIT and at the RXTE SOF and GOF at NASA's GSFC.

  7. Measurements of laser generated soft X-ray emission from irradiated gold foils

    Energy Technology Data Exchange (ETDEWEB)

    Davis, J. S.; Keiter, P. A.; Klein, S. R.; Drake, R. P.; Shvarts, D. [University of Michigan, 2455 Hayward St., Ann Arbor, Michigan 48109 (United States); Frank, Y.; Raicher, E.; Fraenkel, M. [Soreq Nuclear Research Center, Yavne (Israel)

    2016-11-15

    Soft x-ray emission from laser irradiated gold foils was measured at the Omega-60 laser system using the Dante photodiode array. The foils were heated with 2 kJ, 6 ns laser pulses and foil thicknesses were varied between 0.5, 1.0, and 2.0 μm. Initial Dante analysis indicates peak emission temperatures of roughly 100 eV and 80 eV for the 0.5 μm and 1.0 μm thick foils, respectively, with little measurable emission from the 2.0 μm foils.

  8. Highly ionized copper contribution to the soft X-ray emission in a plasma focus device

    Energy Technology Data Exchange (ETDEWEB)

    Zoita, V; Patran, A [Inst. of Physics and Technology of Radiation Devices, Bucharest (Romania); Larour, J [Ecole Polytechnique, Palaiseau (France). Lab. de Physique des Milieux Ionises

    1997-12-31

    In order to discriminate between the contributions of the gas plasma and of the anode (solid or plasma) to the soft X-ray emission in a plasma focus device, a series of experiments was carried out using the following combinations of experimental conditions: various gases, different absorption filters and viewing different regions in front of the centre electrode. The experiments were performed on the IPF-2/20 plasma focus device using the following working gases: helium, neon and helium-argon mixtures. The diagnostics used: magnetic probe for current derivative, PIN diode for the minimum pinch radius detection, PIN diodes for the soft X-ray emission, scintillator-photomultiplier detector for the hard X-ray emission. From the analysis of the various diagnostics data recorded with very good time correlation, it followed that the soft K-ray signals had a strong contribution from optical transitions of the highly ionised Cu (Cu XX to XXII) emitting in the range 0.8-1.3 nm. (author). 7 figs., 9 refs.

  9. Recent measurements of soft X-ray emission from the DPF-1000U facility

    Directory of Open Access Journals (Sweden)

    Surała Władysław

    2015-06-01

    Full Text Available Soft X-ray imaging is a very useful diagnostic technique in plasma-focus (PF experiments. This paper reports results of four experimental sessions which were carried out at the DPF-1000U plasma-focus facility in 2013 and 2014. Over 200 discharges were performed at various experimental conditions. Measurements were taken using two X-ray pinhole cameras with a line of sight perpendicular to the z-axis, at different azimuthal angles (about 20° and 200°, and looking towards the centre of the PF-pinch column. They were equipped with diaphragms 1000 μm or 200–300 μm in diameter and coated with filters of 500 μm Al foil and 10 μm Be foil, respectively. Data on the neutron emission were collected with silver activation counters. For time-resolved measurements the use was made of four PIN diodes equipped with various filters and oriented towards the centre of the PF-column, in the direction perpendicular to the electrode axis. The recorded X-ray images revealed that when the additional gas-puff system is activated during the discharge, the stability of the discharge is improved. The data collected in these experiments confirmed the appearance of a filamentary fine structure in the PF discharges. In the past years the formation of such filaments was observed in many Z-pinch type experiments. Some of the recorded X-ray images have also revealed the appearance of the so-called hot-spots, i.e. small plasma regions of a very intense X-ray emission. Such a phenomenon was observed before in many PF experiments, e.g. in the MAJA-PF device, but it has not been investigated so far in a large facility such as the DPF-1000U. The time-resolved measurements provided the evidence of a time lapse between the X-ray emission from plasma regions located at different distance from the anode surface. The formation of distinct ‘hot-spots’ in different instants of the DPF-1000U discharge was also observed.

  10. INVERSE COMPTON X-RAY EMISSION FROM SUPERNOVAE WITH COMPACT PROGENITORS: APPLICATION TO SN2011fe

    International Nuclear Information System (INIS)

    Margutti, R.; Soderberg, A. M.; Chomiuk, L.; Milisavljevic, D.; Foley, R. J.; Slane, P.; Moe, M.; Chevalier, R.; Hurley, K.; Hughes, J. P.; Fransson, C.; Barthelmy, S.; Cummings, J.; Boynton, W.; Enos, H.; Fellows, C.; Briggs, M.; Connaughton, V.; Costa, E.; Del Monte, E.

    2012-01-01

    We present a generalized analytic formalism for the inverse Compton X-ray emission from hydrogen-poor supernovae and apply this framework to SN 2011fe using Swift X-Ray Telescope (XRT), UVOT, and Chandra observations. We characterize the optical properties of SN 2011fe in the Swift bands and find them to be broadly consistent with a 'normal' SN Ia, however, no X-ray source is detected by either XRT or Chandra. We constrain the progenitor system mass-loss rate M-dot -9 M ☉ yr -1 (3σ c.l.) for wind velocity v w = 100 km s –1 . Our result rules out symbiotic binary progenitors for SN 2011fe and argues against Roche lobe overflowing subgiants and main-sequence secondary stars if ∼> 1% of the transferred mass is lost at the Lagrangian points. Regardless of the density profile, the X-ray non-detections are suggestive of a clean environment (n CSM –3 ) for 2 × 10 15 ∼ 16 cm around the progenitor site. This is either consistent with the bulk of material being confined within the binary system or with a significant delay between mass loss and supernova explosion. We furthermore combine X-ray and radio limits from Chomiuk et al. to constrain the post-shock energy density in magnetic fields. Finally, we searched for the shock breakout pulse using gamma-ray observations from the Interplanetary Network and find no compelling evidence for a supernova-associated burst. Based on the compact radius of the progenitor star we estimate that the shock breakout pulse was likely not detectable by current satellites.

  11. DISCOVERY OF X-RAY EMISSION FROM THE FIRST Be/BLACK HOLE SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Munar-Adrover, P.; Paredes, J. M.; Ribó, M. [Departament d' Astronomia i Meteorologia, Institut de Ciències del Cosmos, Universitat de Barcelona, IEEC-UB, Martí i Franquès 1, E-08028 Barcelona (Spain); Iwasawa, K. [ICREA, Institut de Ciències del Cosmos, Universitat de Barcelona, IEEC-UB, Martí i Franquès 1, E-08028 Barcelona (Spain); Zabalza, V. [Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom); Casares, J. [Instituto de Astrofísica de Canarias, E-38200 La Laguna, Tenerife (Spain)

    2014-05-10

    MWC 656 (=HD 215227) was recently discovered to be the first binary system composed of a Be star and a black hole (BH). We observed it with XMM-Newton, and detected a faint X-ray source compatible with the position of the optical star, thus proving it to be the first Be/BH X-ray binary. The spectrum analysis requires a model fit with two components, a blackbody plus a power law, with k{sub B}T=0.07{sub −0.03}{sup +0.04} keV and a photon index Γ = 1.0 ± 0.8, respectively. The non-thermal component dominates above ≅0.8 keV. The obtained total flux is F(0.3-5.5 keV)=(4.6{sub −1.1}{sup +1.3})×10{sup −14} erg cm{sup –2} s{sup –1}. At a distance of 2.6 ± 0.6 kpc the total flux translates into a luminosity L {sub X} = (3.7 ± 1.7) × 10{sup 31} erg s{sup –1}. Considering the estimated range of BH masses to be 3.8-6.9 M {sub ☉}, this luminosity represents (6.7 ± 4.4) × 10{sup –8} L {sub Edd}, which is typical of stellar-mass BHs in quiescence. We discuss the origin of the two spectral components: the thermal component is associated with the hot wind of the Be star, whereas the power-law component is associated with emission from the vicinity of the BH. We also find that the position of MWC 656 in the radio versus X-ray luminosity diagram may be consistent with the radio/X-ray correlation observed in BH low-mass X-ray binaries. This suggests that this correlation might also be valid for BH high-mass X-ray binaries (HMXBs) with X-ray luminosities down to ∼10{sup –8} L {sub Edd}. MWC 656 will allow the accretion processes and the accretion/ejection coupling at very low luminosities for BH HMXBs to be studied.

  12. Development of a fast multi-line x-ray CT detector for NDT

    International Nuclear Information System (INIS)

    Hofmann, T.; Nachtrab, F.; Schlechter, T.; Mühlbauer, J.; Schröpfer, S.; Firsching, M.; Uhlmann, N.; Neubauer, H.; Ernst, J.; Schweiger, T.; Oberst, M.; Meyer, A.

    2015-01-01

    Typical X-ray detectors for non-destructive testing (NDT) are line detectors or area detectors, like e.g. flat panel detectors. Multi-line detectors are currently only available in medical Computed Tomography (CT) scanners. Compared to flat panel detectors, line and multi-line detectors can achieve much higher frame rates. This allows time-resolved 3D CT scans of an object under investigation. Also, an improved image quality can be achieved due to reduced scattered radiation from object and detector themselves. Another benefit of line and multi-line detectors is that very wide detectors can be assembled easily, while flat panel detectors are usually limited to an imaging field with a size of approx. 40 × 40 cm 2 at maximum. The big disadvantage of line detectors is the limited number of object slices that can be scanned simultaneously. This leads to long scan times for large objects. Volume scans with a multi-line detector are much faster, but with almost similar image quality. Due to the promising properties of multi-line detectors their application outside of medical CT would also be very interesting for NDT. However, medical CT multi-line detectors are optimized for the scanning of human bodies. Many non-medical applications require higher spatial resolutions and/or higher X-ray energies. For those non-medical applications we are developing a fast multi-line X-ray detector.In the scope of this work, we present the current state of the development of the novel detector, which includes several outstanding properties like an adjustable curved design for variable focus-detector-distances, conserving nearly uniform perpendicular irradiation over the entire detector width. Basis of the detector is a specifically designed, radiation hard CMOS imaging sensor with a pixel pitch of 200 μ m. Each pixel has an automatic in-pixel gain adjustment, which allows for both: a very high sensitivity and a wide dynamic range. The final detector is planned to have 256 lines of

  13. Fast X-ray imaging of two-phase flows: Application to cavitating flows

    International Nuclear Information System (INIS)

    Khlifa, Ilyass

    2014-01-01

    A promising method based on fast X-ray imaging has been developed to investigate the dynamics and the structure of complex two-phase flows. It has been applied in this work on cavitating flows created inside a Venturi-type test section and helped therefore to better understand flows inside cavitation pockets. Seeding particles were injected into the flow to trace the liquid phase. Thanks to the characteristics of the beam provided by the APS synchrotron (Advance Photon Source, USA), high definition X-ray images of the flow containing simultaneously information for both liquid and vapour were obtained. Velocity fields of both phases were thus calculated using image cross-correlation algorithms. Local volume fractions of vapour have also been obtained using local intensities of the images. Beforehand however, image processing is required to separate phases for velocity measurements. Validation methods of all applied treatments were developed, they allowed to characterise the measurement accuracy. This experimental technique helped us to have more insight into the dynamic of cavitating flows and especially demonstrates the presence of significant slip velocities between phases. (author)

  14. Spectral properties of X-ray selected narrow emission line galaxies

    Science.gov (United States)

    Romero-Colmenero, E.

    1998-03-01

    This thesis reports a study of the X-ray and optical properties of two samples of X-ray selected Narrow Emission Line Galaxies (NELGs), and their comparison with the properties of broad line Active Galactic Nuclei (AGN). One sample (18 NELGs) is drawn from the ROSAT International X-ray Optical Survey (RIXOS), the other (19 NELGs and 33 AGN) from the ROSAT UK Deep Survey. ROSAT multi-channel X-ray spectra have been extracted and fitted with power-law, bremsstrahlung and black body models for the brighter RIXOS sources. In most cases, power-law and bremsstrahlung models provide the best results. The average spectral energy index, alpha, of the RIXOS NELGs is 0.96 +/- 0.07, similar to that of AGN (alpha~1). For the fainter RIXOS NELGs, as well as for all the UK Deep Survey sources, counts in three spectral bands have been extracted and fitted with a power-law model, assuming the Galactic value for N_H. The brighter RIXOS sources demonstrated that the results obtained by these two different extraction and fitting procedures provide consistent results. Two average X-ray spectra, one for the NELGs and another for the AGN, were created from the UK Deep Survey sources. The power-law slope of the average NELG is alpha = 0.45 +/- 0.09, whilst that of the AGN is alpha = 0.96 +/- 0.03. ROSAT X-ray surveys have shown that the fractional surface density of NELGs increases with respect to AGN at faint fluxes (case for NELGs to be major contributors to the XRB at the fainter fluxes. The analysis of optical spectroscopy, obtained on La Palma and Hawaii, shows that NELGs form a very heterogeneous group, made up of a mixture of Seyfert 2, LINER and HII-region like galaxies. Seyfert 2 galaxies are found to possess in general the steepest X-ray slopes. Ways to explain this in the context of the unified model of AGN are discussed. The FWHM of some emission lines (Halpha, Hbeta, [NII]) in the NELGs appears to increase with steepening X-ray spectral slope. In the case of the Balmer lines

  15. A comparative study of the ionic keV X-ray line emission from ...

    Indian Academy of Sciences (India)

    resolved X-ray diffraction [15] etc. High conversion efficiency of the laser ... picosecond ionic X-ray pulses are produced when both the plasma density and the tem- ..... X-ray spectrum of magnesium plasma produced using femtosecond laser.

  16. Temporal feature of X-ray laser plasma observed from 3ω0/2, 2ω0 harmonic emission

    International Nuclear Information System (INIS)

    Li Wenhong; Mei Qiyong; Zhao Xuewei; Chen Yuting; Chunyu Shutai

    1995-01-01

    Temporal feature of X-ray laser plasma density was observed from 3ω 0 /2, 2ω 0 harmonic emission in the experiments. The temporal feature of 3ω 0 /2 harmonic emission of the germanium film is much different from that of the slab germanium target. The production of x-ray laser is closely related to 3ω 0 /2 harmonic emission in the slab germanium targets

  17. Fast and robust ray casting algorithms for virtual X-ray imaging

    International Nuclear Information System (INIS)

    Freud, N.; Duvauchelle, P.; Letang, J.M.; Babot, D.

    2006-01-01

    Deterministic calculations based on ray casting techniques are known as a powerful alternative to the Monte Carlo approach to simulate X- or γ-ray imaging modalities (e.g. digital radiography and computed tomography), whenever computation time is a critical issue. One of the key components, from the viewpoint of computing resource expense, is the algorithm which determines the path length travelled by each ray through complex 3D objects. This issue has given rise to intensive research in the field of 3D rendering (in the visible light domain) during the last decades. The present work proposes algorithmic solutions adapted from state-of-the-art computer graphics to carry out ray casting in X-ray imaging configurations. This work provides an algorithmic basis to simulate direct transmission of X-rays, as well as scattering and secondary emission of radiation. Emphasis is laid on the speed and robustness issues. Computation times are given in a typical case of radiography simulation

  18. Fast and robust ray casting algorithms for virtual X-ray imaging

    Energy Technology Data Exchange (ETDEWEB)

    Freud, N. [CNDRI, Laboratory of Nondestructive Testing Using Ionizing Radiations, INSA-Lyon Scientific and Technical University, Bat. Antoine de Saint-Exupery, 20, Avenue Albert Einstein, 69621 Villeurbanne Cedex (France)]. E-mail: Nicolas.Freud@insa-lyon.fr; Duvauchelle, P. [CNDRI, Laboratory of Nondestructive Testing Using Ionizing Radiations, INSA-Lyon Scientific and Technical University, Bat. Antoine de Saint-Exupery, 20, Avenue Albert Einstein, 69621 Villeurbanne Cedex (France); Letang, J.M. [CNDRI, Laboratory of Nondestructive Testing Using Ionizing Radiations, INSA-Lyon Scientific and Technical University, Bat. Antoine de Saint-Exupery, 20, Avenue Albert Einstein, 69621 Villeurbanne Cedex (France); Babot, D. [CNDRI, Laboratory of Nondestructive Testing Using Ionizing Radiations, INSA-Lyon Scientific and Technical University, Bat. Antoine de Saint-Exupery, 20, Avenue Albert Einstein, 69621 Villeurbanne Cedex (France)

    2006-07-15

    Deterministic calculations based on ray casting techniques are known as a powerful alternative to the Monte Carlo approach to simulate X- or {gamma}-ray imaging modalities (e.g. digital radiography and computed tomography), whenever computation time is a critical issue. One of the key components, from the viewpoint of computing resource expense, is the algorithm which determines the path length travelled by each ray through complex 3D objects. This issue has given rise to intensive research in the field of 3D rendering (in the visible light domain) during the last decades. The present work proposes algorithmic solutions adapted from state-of-the-art computer graphics to carry out ray casting in X-ray imaging configurations. This work provides an algorithmic basis to simulate direct transmission of X-rays, as well as scattering and secondary emission of radiation. Emphasis is laid on the speed and robustness issues. Computation times are given in a typical case of radiography simulation.

  19. Extracting chemical information from high-resolution Kβ X-ray emission spectroscopy

    Science.gov (United States)

    Limandri, S.; Robledo, J.; Tirao, G.

    2018-06-01

    High-resolution X-ray emission spectroscopy allows studying the chemical environment of a wide variety of materials. Chemical information can be obtained by fitting the X-ray spectra and observing the behavior of some spectral features. Spectral changes can also be quantified by means of statistical parameters calculated by considering the spectrum as a probability distribution. Another possibility is to perform statistical multivariate analysis, such as principal component analysis. In this work the performance of these procedures for extracting chemical information in X-ray emission spectroscopy spectra for mixtures of Mn2+ and Mn4+ oxides are studied. A detail analysis of the parameters obtained, as well as the associated uncertainties is shown. The methodologies are also applied for Mn oxidation state characterization of double perovskite oxides Ba1+xLa1-xMnSbO6 (with 0 ≤ x ≤ 0.7). The results show that statistical parameters and multivariate analysis are the most suitable for the analysis of this kind of spectra.

  20. Role of screening and angular distributions in resonant soft-x-ray emission of CO

    Energy Technology Data Exchange (ETDEWEB)

    Skytt, P.; Glans, P.; Gunnelin, K. [Uppsala Univ. (Sweden)] [and others

    1997-04-01

    In the present work the authors focus on two particular properties of resonant X-ray emission, namely core hole screening of the excited electron, and anisotropy caused by the polarization of the exciting synchrotron radiation. The screening of the core hole by the excited electron causes energy shifts and intensity variations in resonant spectra compared to the non-resonant case. The linear polarization of the synchrotron radiation and the dipole nature of the absorption process create a preferential alignment selection of the randomly oriented molecules in the case of resonant excitation, producing an anisotropy in the angular distribution of the emitted X-rays. The authors have chosen CO for this study because this molecule has previously served as a showcase for non-resonant X-ray emission, mapping the valence electronic structure differently according to the local selection rules. With the present work they take interest in how this characteristic feature of the spectroscopy is represented in the resonant case.

  1. Determination of impurities in silicon nitride by particle induced x-ray emission analysis

    International Nuclear Information System (INIS)

    Miyagawa, Yoshiko; Saito, Kazuo; Niwa, Hiroaki; Ishizuka, Toshio; Miyagawa, Soji

    1985-01-01

    A method is presented for quantitative particle induced X-ray emission (PIXE) analysis of impurities in the thick samples of silicon nitride. In the analysis of ceramic materials such as silicon nitride, chemical treatments are required to prepare thin enough samples. However, the chemical treatments are undesirable for the PIXE analysis, because another complications are brought about. Our method does not need any chemical treatments and thick samples can be subjected to the measurements. The determination of impurities were made by on-line use of a personal computer in which standard X-ray intensity data were stored. The method and procedures are as follows: After subtracting a buckground spectrum from an observed PIXE spectrum, the resultant peaks are assigned to individual elements. Then, in order to determine the contents of the impurities, the intensity of each peak is compared with a Gaussian curve which is generated from the standard X-ray intensity data. The latter data were determined theoretically. The results were in satisfactory agreement with those obtained by ICP emission spectrometry. (author)

  2. Electron-electron correlation, resonant photoemission and X-ray emission spectra

    International Nuclear Information System (INIS)

    Parlebas, J.C.; Kotani, Akio; Tanaka, Satoshi.

    1991-01-01

    In this short review paper we essentially focus on the high energy spectroscopies which involve second order quantum processes, i.e., resonance photoemission, Auger and X-ray emission spectroscopies, denoted respectively by RXPS, AES and XES. First, we summarize the main 3p-RXPS and AES results obtained in Cu and Ni metals; especially we recall that the satellite near the 3p-threshold in the spectra, which arises from a d-hole pair bound state, needs a careful treatment of the electron-electron correlation. Then we analyze the RXPS spectra in a few Ce compounds (CeO 2 , Ce 2 O 3 and CeF 3 ) involving 3d or 4d core levels and we interpret the spectra consistently with the other spectroscopies, such as core XPS and XAS which are first order quantum processes. Finally within the same one-impurity model and basically with the same sets of parameters, we review a theory for the Ce 5p→3d XES, as well as for the corresponding RXES, where (1) the incident X-ray is tuned to resonate with the 3d→4f transition and (2) the X-ray emission due to the 5p→3d transition is actually observed. The paper ends with a general discussion. (author) 77 refs

  3. Study of X-ray emission in aluminium z-pinches; Etude de l'emission X dans les plasmas d'aluminium de type Z-pinch

    Energy Technology Data Exchange (ETDEWEB)

    Rosch, R [CEA/DAM-Ile de France, Dept. de Conception et Realisation des Experimentations (DCRE), 91 - Bruyeres-le-Chatel (France); [Paris-11 Univ., 91 - Orsay (France)

    1999-07-01

    Previous experiments, at 0.1. TX level, have shown that stability and x-ray emission of fast Z-pinches, could be strongly increased by imploding an aluminium vapor jet onto a very thin coaxial wire. We present here first results of an aluminium Z-pinch, using a similar liner, but at mega-ampere level. The pinch is driven by AMBIORIX high-power facility, a 2 TW,0.5 {omega}, 2 MA, 50 ns pulse-line generator. We study the effect of an aluminium wire and its diameter (20-50 {mu}m) on the implosion dynamics, on x-ray yield on MHD stability of the column at stagnation. Analysis of A1 jet on A1 wire shots demonstrates that x-ray yield due to emission processes in the H- and He- like ionization stages (i.e. the K-shell) is significantly enhanced, relative to that of A1 jet only ones. The wire also leads to better symmetry of the implosion, and to better reproducibility of shots. X-ray signals exhibit two similar pulses, 10 ns in width, 15 ns spaced. To discern spectral origin of both pulses, experiments are realized with stainless steel wire (25 {mu}m in diameter). Results show that liner and wire radial simultaneously and contribute to both pulses. Analysis of a typical A1 jet on A1 wire shot, using detailed collisional-radiative equilibrium (CRE) model is also given in this thesis. View o the pinch at stagnation as a cola-dense core surrounded by a hot-low density corona reproduces all features of the X-ray data. (author)

  4. Reconnection, Particle Acceleration, and Hard X-ray Emission in Eruptive Solar Flares

    Science.gov (United States)

    Martens, Petrus C.

    1998-11-01

    The frequent occurrence of Hard X-ray emission from the top of flaring loops was one of the discoveries by the Hard X-ray telescope on board the Japanese Yohkoh satellite. I will show how the combined effect of magnetic field convergence and pitch- angle scattering of non-thermal electrons injected at the top of the loop results in the generation of looptop sources with properties akin to those observed by Yohkoh. In addition it is shown that the injection of proton beams in the loop legs, expected from theory, reproduces the observed high temperature ``ridges" in the loop legs by mirroring and energy loss through collisions. I will interpret these numerical results as supporting the now widely accepted model of an erupting magnetic flux tube generating a reconnecting current sheet in its wake, where most of the energy release takes place. The strong similarity with the reconnection observed in the MRX experiment in Princeton will be analyzed in detail.

  5. Particle induced x-ray emission (PIXE) measurement of the Cd content in animal tissues

    International Nuclear Information System (INIS)

    Le Huong Quynh; Demeter, I.; Hollos-Nagy, K.; Szoekefalvi-Nagy, Z.

    1989-12-01

    Particle induced x-ray emission (PIXE) measurements were performed on thin samples prepared from different rabbit tissues, using 3 MeV proton beam for inducing x-rays from the animal tissues. This method is very sensitive and very small amounts of trace elements can be detected. Cadmium, one of the most toxic elements which can be concentrated in animal and human tissues due to environmental pollution, was detected with a limit of 0.7 ppm. The trace element concentrations obtained by PIXE were compared to those measured by atomic absorption spectrometry. PIXE method is proposed for routine analysis at the Veterinary and Food Investigating Service, Budapest, Hungary. (D.Gy.) 6 refs.; 3 figs

  6. Changes of soft X-ray emission spectra of oxygen and copper in high Tc superconductors

    International Nuclear Information System (INIS)

    Fukushima, Sei; Gohshi, Yohichi; Kohiki, Shigemi; Saitoh, Naoki

    1989-01-01

    X-ray induced soft X-ray emission spectroscopy is one of the bulk analysis methods used to characterize high-Tc superconductor. In this report, some observations on the changes in O Kα and Cu L spectra of thin layer LnBa 2 Cu 3 O 7-δ (Ln=Er,Gd) samples are presented. From the measurement of O Kα, no discernible difference was found between those of Gd compounds which were composed single phase or not. It may be said that the electronic structure of p state localized on the O is not sensitive to the change of Tc or zero-resistance temperature. From the measurement of Cu L spectra, it was found that Cu Lα of only Gd containing compounds has a low energy shoulder

  7. Multielement proton-induced x-ray emission analysis of Bangladeshi tobacco

    International Nuclear Information System (INIS)

    Hadi, D.A.; Ali, M.; Biswas, S.K.; Islam, M.M.; Khan, A.H.

    1984-01-01

    The concentration of 12 different elements in cigarette tobacco of different brands, commercially made in Bangladesh, was determined using the proton particle-induced x-ray emission (proton PIXE) method. In all the present experiments, proton beams of 2.0 MeV (on the target in air) and about 30 nA current were used for characteristic x-ray excitation. The concentration of the elements (K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Br, Rb and Sr) was determined by comparison with a calibration obtained from the NBS orchard leaf standard SRM 1571. The results have been compared with available data on some foreign brands of tobacco and the probable reasons for the difference in the contents of some of the elements found in the Bangladeshi brands are discussed. (author)

  8. Standardization of proton-induced x-ray emission technique for analysis of thick samples

    Science.gov (United States)

    Ali, Shad; Zeb, Johar; Ahad, Abdul; Ahmad, Ishfaq; Haneef, M.; Akbar, Jehan

    2015-09-01

    This paper describes the standardization of the proton-induced x-ray emission (PIXE) technique for finding the elemental composition of thick samples. For the standardization, three different samples of standard reference materials (SRMs) were analyzed using this technique and the data were compared with the already known data of these certified SRMs. These samples were selected in order to cover the maximum range of elements in the periodic table. Each sample was irradiated for three different values of collected beam charges at three different times. A proton beam of 2.57 MeV obtained using 5UDH-II Pelletron accelerator was used for excitation of x-rays from the sample. The acquired experimental data were analyzed using the GUPIXWIN software. The results show that the SRM data and the data obtained using the PIXE technique are in good agreement.

  9. Chemical Analysis of Impurity Boron Atoms in Diamond Using Soft X-ray Emission Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Muramatsu, Yasuji; Iihara, Junji; Takebe, Toshihiko; Denlinger, Jonathan D.

    2008-03-29

    To analyze the local structure and/or chemical states of boron atoms in boron-doped diamond, which can be synthesized by the microwave plasma-assisted chemical vapor deposition method (CVD-B-diamond) and the temperature gradient method at high pressure and high temperature (HPT-B-diamond), we measured the soft X-ray emission spectra in the CK and BK regions of B-diamonds using synchrotron radiation at the Advanced Light Source (ALS). X-ray spectral analyses using the fingerprint method and molecular orbital calculations confirm that boron atoms in CVD-B-diamond substitute for carbon atoms in the diamond lattice to form covalent B-C bonds, while boron atoms in HPT-B-diamond react with the impurity nitrogen atoms to form hexagonal boron nitride. This suggests that the high purity diamond without nitrogen impurities is necessary to synthesize p-type B-diamond semiconductors.

  10. Massive stars, x-ray ridge, and galactic 26Al gamma-ray line emission

    International Nuclear Information System (INIS)

    Montmerle, T.

    1986-07-01

    Massive stars interact with their parent molecular cloud by means of their ionizing flux and strong winds, thereby creating giant, hollow HII regions. To account for the observed structure of these HII regions, it appears necessary that all the wind energy be dissipated. Dorland and Montmerle have recently proposed a new dissipation mechanism, in the process, diffuse hard X-rays are emitted. If the observed galactic X-ray ''ridge'' results from this process on a galactic scale, it can be accounted for by the interaction of ∼3000 Wolf-Rayet stars (mostly within a ∼6.5 kpc ring) with their surrounding interstellar gas. This result is essentially consistent with the suggestion by Prantzos and Casse that the galactic 26 Al γ-ray line emission originates in Wolf-Rayet stars

  11. Sample analysis using gamma ray induced fluorescent X-ray emission

    Energy Technology Data Exchange (ETDEWEB)

    Sood, B S; Allawadhi, K L; Gandhi, R; Batra, O P; Singh, N [Punjabi Univ., Patiala (India). Nuclear Science Labs.

    1983-01-01

    A non-destructive method for the analysis of materials using gamma ray-induced fluorescent x-ray emission has been developed. In this method, special preparation of very thin samples in which the absorption of the incident gamma rays and the emitted fluorescent x-rays is negligible, is not needed, and the absorption correction is determined experimentally. A suitable choice of the incident gamma ray energies is made to minimise enhancement effects through selective photoionization of the elements in the sample. The method is applied to the analysis of a typical sample of the soldering material using 279 keV and 59.5 keV gamma rays from /sup 203/Hg and /sup 241/Am radioactive sources respectively. The results of the analysis are found to agree well with those obtained from the chemical analysis.

  12. Proton induced x-ray emission analysis of trace elements in thick bread samples

    International Nuclear Information System (INIS)

    Mohamed Baker Al-bedri; Ikram Jameel Abdul Ghani; Ibrahim Abdul Rahman Al-aghil

    2009-01-01

    Proton induced X-ray emission (PIXE) technique has been used for identification and quantitative analysis of the elemental concentration in thick bread samples. Bread samples were air-oven dried at 60degC and milled in a clean agate mortar to homogenize the sample and pressed into a pellet. PIXE technique relies on the analysis of the energy spectra of the characteristic X-ray emitted from the thick bread sample and the orchard leaf standard (NIST-SRM-1571) bombarded with 2.0 MeV protons. The concentration of the elements (Cl, K, Ca, Mn, Fe, Cu, and Zn) in the bread samples was determined by comparison with NIST orchard leaf standard. The accuracy of the measurements ranged between ±2% and ±10% for the most elements detected in this method. The aim of this study is to establish the reference concentration of trace elements in the Iraqi bread using PIXE technique. (author)

  13. A review of molecular effects in gas-phase KL X-ray emission

    Energy Technology Data Exchange (ETDEWEB)

    Guillemin, Renaud; Carniato, Stéphane; Journel, Loïc [UPMC Univ Paris 06, UMR 7614, Laboratoire de Chimie Physique Matière et Rayonnement, F-75005 Paris (France); CNRS, UMR 7614, Laboratoire de Chimie Physique Matière et Rayonnement, F-75005 Paris (France); Stolte, Wayne C. [Department of Chemistry, University of Nevada, Las Vegas, NV 89154-4003 (United States); Marchenko, Tatiana; Khoury, Lara El; Kawerk, Elie; Piancastelli, Maria Novella [UPMC Univ Paris 06, UMR 7614, Laboratoire de Chimie Physique Matière et Rayonnement, F-75005 Paris (France); CNRS, UMR 7614, Laboratoire de Chimie Physique Matière et Rayonnement, F-75005 Paris (France); Hudson, Amanda C.; Lindle, Dennis W. [Department of Chemistry, University of Nevada, Las Vegas, NV 89154-4003 (United States); Simon, Marc, E-mail: marc.simon@upmc.fr [UPMC Univ Paris 06, UMR 7614, Laboratoire de Chimie Physique Matière et Rayonnement, F-75005 Paris (France); CNRS, UMR 7614, Laboratoire de Chimie Physique Matière et Rayonnement, F-75005 Paris (France)

    2013-06-15

    The unique capabilities of resonant inelastic X-ray scattering (RIXS) to provide a deep insight into molecular dynamics following core excitation are reviewed here. Characteristic features of molecular X-ray emission are experimentally observed and theoretically interpreted. Some of our most significant results on molecular dynamics following deep core excitation are presented. In particular, we provide several examples of nuclear dynamics on the femtosecond or subfemtosecond time scale; line-narrowing effects related to the quenching of vibrational structure due to parallelism of intermediate and final state curves; anomalous line dispersion across a resonance, which is due to core-hole lifetime effects; spin–orbit-state populations derived from polarized RIXS experiments. We also show how to connect the RIXS results to the general chemical properties of the investigated systems.

  14. A review of molecular effects in gas-phase KL X-ray emission

    International Nuclear Information System (INIS)

    Guillemin, Renaud; Carniato, Stéphane; Journel, Loïc; Stolte, Wayne C.; Marchenko, Tatiana; Khoury, Lara El; Kawerk, Elie; Piancastelli, Maria Novella; Hudson, Amanda C.; Lindle, Dennis W.; Simon, Marc

    2013-01-01

    The unique capabilities of resonant inelastic X-ray scattering (RIXS) to provide a deep insight into molecular dynamics following core excitation are reviewed here. Characteristic features of molecular X-ray emission are experimentally observed and theoretically interpreted. Some of our most significant results on molecular dynamics following deep core excitation are presented. In particular, we provide several examples of nuclear dynamics on the femtosecond or subfemtosecond time scale; line-narrowing effects related to the quenching of vibrational structure due to parallelism of intermediate and final state curves; anomalous line dispersion across a resonance, which is due to core-hole lifetime effects; spin–orbit-state populations derived from polarized RIXS experiments. We also show how to connect the RIXS results to the general chemical properties of the investigated systems

  15. The Multi-component X-ray Emission of 3C 273

    Science.gov (United States)

    Soldi, S.; Türler, M.; Paltani, S.; Courvoisier, T. J.-L.

    2009-05-01

    3C 273 is the brightest quasar in the sky and among the most extensively observed and studied AGN, therefore one of the most suitable targets for a long-term, multi-frequency study. The superposition of a thermal Comptonisation component, similar to that observed in Seyfert galaxies, and of a non-thermal component, related to the jet emission, seems to explain some of the spectral and timing properties of the X-ray emission of 3C 273. Yet, during some observations this dichotomy has not been observed and the variability properties could also be consistent with a single-component scenario, characterised by two parameters varying independently. In order to understand the nature of the X-ray emission in 3C 273, a series of observations up to 80-100 keV, possibly catching the source in different flux states, are essential. Simbol-X will be able to study the emission of 3C 273 in the broad 0.5-80 keV band with high sensitivity, allowing us to disentangle the emission from different spectral components, with 20-30 ks long observations. In addition, the shape and the origin of the high-energy emission of this quasar will be further constrained thanks to the AGILE and Fermi satellites, monitoring the γ-ray sky in the MeV-GeV energy domain.

  16. X-ray emission, ablation pressure, and preheating for foils irradiated at 0. 26. mu. m wavelength

    Energy Technology Data Exchange (ETDEWEB)

    Pepin, H.; Fabbro, R.; Faral, B.; Amiranoff, F.; Virmont, J.; Cottet, F.; Romain, J.P.

    1985-11-01

    The x-ray emission, ablation pressure, and preheating for foils irradiated with a 0.26 ..mu..m laser at intensities approx.10/sup 15/ W cm/sup -2/ are studied. The foils are Al with various thicknesses, coated or uncoated with CH or Au. The x-ray emission and conversion efficiency are obtained with a multichannel x-ray diode spectrometer, the ablation pressures are deduced from shock transit times, and the rear temperatures are inferred from x-ray pyrometry. For thin foils (<<12 ..mu..m), the rear temperatures can be predicted reasonably well with the use of the front x-ray spectra. For thick foils shock preheating is dominant.

  17. X-ray emission, ablation pressure, and preheating for foils irradiated at 0.26 μm wavelength

    International Nuclear Information System (INIS)

    Pepin, H.; Fabbro, R.; Faral, B.; Amiranoff, F.; Virmont, J.; Cottet, F.; Romain, J.P.

    1985-01-01

    The x-ray emission, ablation pressure, and preheating for foils irradiated with a 0.26 μm laser at intensities approx.10 15 W cm -2 are studied. The foils are Al with various thicknesses, coated or uncoated with CH or Au. The x-ray emission and conversion efficiency are obtained with a multichannel x-ray diode spectrometer, the ablation pressures are deduced from shock transit times, and the rear temperatures are inferred from x-ray pyrometry. For thin foils (<<12 μm), the rear temperatures can be predicted reasonably well with the use of the front x-ray spectra. For thick foils shock preheating is dominant

  18. X-ray and neutron emission studies in a new Filippov type plasma focus

    Energy Technology Data Exchange (ETDEWEB)

    Babazadeh, A.R.; Banoushi, A. [Technical University of Amirkabir, Tehran (Iran, Islamic Republic of). Dept. of Physics; Roshan, M.V.; Habibi, H.; Nasiry, A.; Memarzadeh, M.; Lamehi, M.; Kiai, S.M. Sadat [Atomic Energy Organization of Iran (AEOI), Tehran (Iran, Islamic Republic of). Nuclear Fusion Research Center

    2002-03-01

    We have performed experimental comparative studies of the X-ray and neutron emission generated by the new Filippov-type plasma focus 'Dena', (90 kJ, 25 kV, 288{mu}F) in the pressure range of 0.6-1 torr. Time-integrated and time-resolved detectors, together with an X-ray pin-hole camera, along with a Be filter of 10{mu}m thickness have been used. For a working gas of neon and a at insert anode, the maximum soft and hard X-rays (SXR-HXR) yield obtained was 16 V and 1.5 V/shot over a 4{pi} solid angle, respectively, for a charging voltage range of 16-20 kV. As for the argon gas, the similar results such as 3.5 and 2 V/shot have been found, leading to a total conversion efficiency of X-ray emission of 0.09 % (for neon) and 0.03 % (for argon) of the stored energy. These efficiencies have been improved by the employment of a conic insert anode up to 0.4% and 0.1%. With deuterium puffing gas and a at insert anode, the maximum emission yield has been found to be 2.5 V for SXR and 1 V for HXR/shot which produce an ultimate emission profile width (FWHM) of 70-90 ns for X-rays and neutrons, giving rise to a maximum neutron yield of 1.2 x 10{sup 9}. Nevertheless, the maximum yield has been increased up to 5.5 times with the conic insert anode. In order to increase the neutron yield, we have introduced a krypton admixture to the deuterium filling gas and found that, for a krypton pressure of about 0.1 torr, the neutron yield increases by a factor of 3.5 for the flat insert and 1.5 for the conic insert anodes. (author)

  19. X-ray emission from plasmas created by smoothed KrF laser irradiation

    International Nuclear Information System (INIS)

    Aglitskiy, Y.; Lehecka, T.; Deniz, A.; Hardgrove, J.; Seely, J.; Brown, C.; Feldman, U.; Pawley, C.; Gerber, K.; Bodner, S.; Obenschain, S.; Lehmberg, R.; McLean, E.; Pronko, M.; Sethian, J.; Stamper, J.; Schmitt, A.; Sullivan, C.; Holland, G.; Laming, M.

    1996-01-01

    The x-ray emission from plasmas created by the Naval Research Laboratory Nike KrF laser [Phys. Plasmas 3, 2098 (1996) ] was characterized using imaging and spectroscopic instruments. The laser wavelength was 1/4 μm, and the beams were smoothed by induced spatial incoherence (ISI). The targets were thin foils of CH, aluminum, titanium, and cobalt and were irradiated by laser energies in the range 100 endash 1500 J. A multilayer mirror microscope operating at an energy of 95 eV recorded images of the plasma with a spatial resolution of 2 μm. The variation of the 95 eV emission across the 800 μm focal spot was 1.3% rms. Using a curved crystal imager operating in the 1 endash 2 keV x-ray region, the density, temperature, and opacity of aluminum plasmas were determined with a spatial resolution of 10 μm perpendicular to the target surface. The spectral line ratios indicated that the aluminum plasmas were relatively dense, cool, and optically thick near the target surface. The absolute radiation flux was determined at 95 eV and in x-ray bandpasses covering the 1 endash 8 keV region. The electron temperature inferred from the slope of the x-ray flux versus energy data in the 5 endash 8 keV region was 900 eV for an incident laser energy of 200 J and an intensity of ≅10 13 W/cm 2

  20. X-RAY ABSORPTION, NUCLEAR INFRARED EMISSION, AND DUST COVERING FACTORS OF AGNs: TESTING UNIFICATION SCHEMES

    Energy Technology Data Exchange (ETDEWEB)

    Mateos, S.; Carrera, F. J.; Alonso-Herrero, A.; Hernán-Caballero, A.; Barcons, X. [Instituto de Física de Cantabria (CSIC-Universidad de Cantabria), E-39005, Santander (Spain); Ramos, A. Asensio; Almeida, C. Ramos [Instituto de Astrofísica de Canarias, E-38205, La Laguna, Tenerife (Spain); Watson, M. G.; Blain, A. [Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom); Caccianiga, A.; Ballo, L. [INAF-Osservatorio Astronomico di Brera, via Brera 28, I-20121 Milano (Italy); Braito, V., E-mail: mateos@ifca.unican.es [INAF-Osservatorio Astronomico di Brera, Via Bianchi 46, I-23807 Merate (Italy)

    2016-03-10

    We present the distributions of the geometrical covering factors of the dusty tori (f{sub 2}) of active galactic nuclei (AGNs) using an X-ray selected complete sample of 227 AGNs drawn from the Bright Ultra-hard XMM-Newton Survey. The AGNs have z from 0.05 to 1.7, 2–10 keV luminosities between 10{sup 42} and 10{sup 46} erg s{sup −1}, and Compton-thin X-ray absorption. Employing data from UKIDSS, 2MASS, and the Wide-field Infrared Survey Explorer in a previous work, we determined the rest-frame 1–20 μm continuum emission from the torus, which we model here with the clumpy torus models of Nenkova et al. Optically classified type 1 and type 2 AGNs are intrinsically different, with type 2 AGNs having, on average, tori with higher f{sub 2} than type 1 AGNs. Nevertheless, ∼20% of type 1 AGNs have tori with large covering factors, while ∼23%–28% of type 2 AGNs have tori with small covering factors. Low f{sub 2} are preferred at high AGN luminosities, as postulated by simple receding torus models, although for type 2 AGNs the effect is certainly small. f{sub 2} increases with the X-ray column density, which implies that dust extinction and X-ray absorption take place in material that share an overall geometry and most likely belong to the same structure, the putative torus. Based on our results, the viewing angle, AGN luminosity, and also f{sub 2} determine the optical appearance of an AGN and control the shape of the rest-frame ∼1–20 μm nuclear continuum emission. Thus, the torus geometrical covering factor is a key ingredient of unification schemes.

  1. Fast X-ray imaging at beamline I13L at Diamond Light Source

    International Nuclear Information System (INIS)

    Fanis, A De; Pešić, Z D; Wagner, U; Rau, C

    2013-01-01

    The imaging branch of the dual-branch beamline I13L at Diamond Light Source has been operational since April 2012. This branch is dedicated to hard X-ray imaging (in-line phase contrast radiography and tomography, and full-field microscopy), with energies in the ranges 6-30keV. At present we aim to achieve spatial resolution of the order of 1 μm over a field of view of l-20mm 2 . This branch aims to excel at imaging experiment of fast dynamic processes, where it is of interest to have short exposure times and high frame rates. To accommodate for this, we prepared for the beamline to operate with 'pink' beam to provide higher flux, an efficient detection system, and rapid data acquisition, transfer, and saving to storage. This contributed paper describes the present situation and illustrate the author's goal for the mid-future.

  2. Fast X-ray imaging at beamline I13L at Diamond Light Source

    Science.gov (United States)

    De Fanis, A.; Pešić, Z. D.; Wagner, U.; Rau, C.

    2013-03-01

    The imaging branch of the dual-branch beamline I13L at Diamond Light Source has been operational since April 2012. This branch is dedicated to hard X-ray imaging (in-line phase contrast radiography and tomography, and full-field microscopy), with energies in the ranges 6-30keV. At present we aim to achieve spatial resolution of the order of 1 μm over a field of view of l-20mm2. This branch aims to excel at imaging experiment of fast dynamic processes, where it is of interest to have short exposure times and high frame rates. To accommodate for this, we prepared for the beamline to operate with "pink" beam to provide higher flux, an efficient detection system, and rapid data acquisition, transfer, and saving to storage. This contributed paper describes the present situation and illustrate the author's goal for the mid-future.

  3. Be Foil ''Filter Knee Imaging'' NSTX Plasma with Fast Soft X-ray Camera

    International Nuclear Information System (INIS)

    B.C. Stratton; S. von Goeler; D. Stutman; K. Tritz; L.E. Zakharov

    2005-01-01

    A fast soft x-ray (SXR) pinhole camera has been implemented on the National Spherical Torus Experiment (NSTX). This paper presents observations and describes the Be foil Filter Knee Imaging (FKI) technique for reconstructions of a m/n=1/1 mode on NSTX. The SXR camera has a wide-angle (28 o ) field of view of the plasma. The camera images nearly the entire diameter of the plasma and a comparable region in the vertical direction. SXR photons pass through a beryllium foil and are imaged by a pinhole onto a P47 scintillator deposited on a fiber optic faceplate. An electrostatic image intensifier demagnifies the visible image by 6:1 to match it to the size of the charge-coupled device (CCD) chip. A pair of lenses couples the image to the CCD chip

  4. Fast GPU-based spot extraction for energy-dispersive X-ray Laue diffraction

    International Nuclear Information System (INIS)

    Alghabi, F.; Schipper, U.; Kolb, A.; Send, S.; Abboud, A.; Pashniak, N.; Pietsch, U.

    2014-01-01

    This paper describes a novel method for fast online analysis of X-ray Laue spots taken by means of an energy-dispersive X-ray 2D detector. Current pnCCD detectors typically operate at some 100 Hz (up to a maximum of 400 Hz) and have a resolution of 384 × 384 pixels, future devices head for even higher pixel counts and frame rates. The proposed online data analysis is based on a computer utilizing multiple Graphics Processing Units (GPUs), which allow for fast and parallel data processing. Our multi-GPU based algorithm is compliant with the rules of stream-based data processing, for which GPUs are optimized. The paper's main contribution is therefore an alternative algorithm for the determination of spot positions and energies over the full sequence of pnCCD data frames. Furthermore, an improved background suppression algorithm is presented.The resulting system is able to process data at the maximum acquisition rate of 400 Hz. We present a detailed analysis of the spot positions and energies deduced from a prior (single-core) CPU-based and the novel GPU-based data processing, showing that the parallel computed results using the GPU implementation are at least of the same quality as prior CPU-based results. Furthermore, the GPU-based algorithm is able to speed up the data processing by a factor of 7 (in comparison to single-core CPU-based algorithm) which effectively makes the detector system more suitable for online data processing

  5. Comparison of simulation to absolute X-ray emission of CH plasma created with the Nike laser

    Energy Technology Data Exchange (ETDEWEB)

    Busquet, M.; Feldman, U.; Klapisch, M. [ARTEP, Inc., Ellicott City, Maryland (contractor to NRL) (United States); Weaver, J.L.; Colombant, D.G.; Mostovych, A.N. [Naval Research Laboratory, Plasma Physics Division, Washington, DC (United States); Seely, J.F. [Naval Research Laboratory, Space Science Division, Washington, DC (United States); Holland, G. [SFA, Inc., Landover, Maryland (contractor to NRL) (United States)

    2006-06-15

    The Nike laser group at the Naval Research Laboratory has an ongoing effort to improve and benchmark the radiation hydrodynamic simulations used to develop pellet designs for inertial confinement fusion. A new post-processor, Virtual Spectro, has been added to the FAST code suite for detailed simulation of non-local thermodynamical equilibrium (non-LTE) spectra, including radiation transport effects and Stark line profile. This new combination enhances our ability to predict the absolute emission of soft X-rays. An absolutely calibrated transmission grating spectrometer and a high resolution grazing incidence spectrometer have been used to collect time integrated and time resolved spectra emitted by CH targets irradiated at laser intensities of about 10 TW/cm{sup 2}. Comparison between these observations and simulations using Virtual Spectro demonstrates excellent agreement (within factor of about 1.5) for the absolute emission. (authors)

  6. Comparison of simulation to absolute X-ray emission of CH plasma created with the Nike laser

    International Nuclear Information System (INIS)

    Busquet, M.; Feldman, U.; Klapisch, M.; Weaver, J.L.; Colombant, D.G.; Mostovych, A.N.; Seely, J.F.; Holland, G.

    2006-01-01

    The Nike laser group at the Naval Research Laboratory has an ongoing effort to improve and benchmark the radiation hydrodynamic simulations used to develop pellet designs for inertial confinement fusion. A new post-processor, Virtual Spectro, has been added to the FAST code suite for detailed simulation of non-local thermodynamical equilibrium (non-LTE) spectra, including radiation transport effects and Stark line profile. This new combination enhances our ability to predict the absolute emission of soft X-rays. An absolutely calibrated transmission grating spectrometer and a high resolution grazing incidence spectrometer have been used to collect time integrated and time resolved spectra emitted by CH targets irradiated at laser intensities of about 10 TW/cm 2 . Comparison between these observations and simulations using Virtual Spectro demonstrates excellent agreement (within factor of about 1.5) for the absolute emission. (authors)

  7. EMISSION LINES BETWEEN 1 AND 2 keV IN COMETARY X-RAY SPECTRA

    Energy Technology Data Exchange (ETDEWEB)

    Ewing, Ian; Christian, Damian J. [Department of Physics and Astronomy, California State University, 18111 Nordhoff Street, Northridge, CA 91330 (United States); Bodewits, Dennis [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Dennerl, Konrad [Max-Planck-Institut fuer extraterrestrische Physik, Postfach 1312, D-85741 Garching Germany (Germany); Lisse, Carey M. [Planetary Exploration Group, Space Department, Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Rd, Laurel, MD 20723 (United States); Wolk, Scott J., E-mail: ian.ewing.794@my.csun.edu, E-mail: daman.christian@csun.edu [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

    2013-01-20

    We present the detection of new cometary X-ray emission lines in the 1.0-2.0 keV range using a sample of comets observed with the Chandra X-Ray Observatory and ACIS spectrometer. We have selected five comets from the Chandra sample with good signal-to-noise spectra. The surveyed comets are C/1999 S4 (LINEAR), C/1999 T1 (McNaught-Hartley), 153P/2002 (Ikeya-Zhang), 2P/2003 (Encke), and C/2008 8P (Tuttle). We modeled the spectra with an extended version of our solar wind charge exchange (SWCX) emission model. Above 1 keV, we find Ikeya-Zhang to have strong emission lines at 1340 and 1850 eV which we identify as being created by SWCX lines of Mg XI and Si XIII, respectively, and weaker emission lines at 1470, 1600, and 1950 eV formed by SWCX of Mg XII, Mg XI, and Si XIV, respectively. The Mg XI and XII and Si XIII and XIV lines are detected at a significant level for the other comets in our sample (LS4, MH, Encke, 8P), and these lines promise additional diagnostics to be included in SWCX models. The silicon lines in the 1700-2000 eV range are detected for all comets, but with the rising background and decreasing cometary emission, we caution that these detections need further confirmation with higher resolution instruments.

  8. Anatomy of the AGN in NGC 5548. IX. Photoionized emission features in the soft X-ray spectra

    Science.gov (United States)

    Mao, Junjie; Kaastra, J. S.; Mehdipour, M.; Gu, Liyi; Costantini, E.; Kriss, G. A.; Bianchi, S.; Branduardi-Raymont, G.; Behar, E.; Di Gesu, L.; Ponti, G.; Petrucci, P.-O.; Ebrero, J.

    2018-04-01

    The X-ray narrow emission line region (NELR) of the archetypal Seyfert 1 galaxy NGC 5548 has been interpreted as a single-phase photoionized plasma that is absorbed by some of the warm absorber components. This scenario requires those overlaying warm absorber components to have larger distance (to the central engine) than the X-ray NELR, which is not fully consistent with the distance estimates found in the literature. Therefore, we reanalyze the high-resolution spectra obtained in 2013-2014 with the Reflection Grating Spectrometer (RGS) aboard XMM-Newton to provide an alternative interpretation of the X-ray narrow emission features. We find that the X-ray narrow emission features in NGC 5548 can be described by a two-phase photoionized plasma with different ionization parameters (logξ = 1.3 and 0.1) and kinematics (vout = -50 and -400 km s-1), and no further absorption by the warm absorber components. The X-ray and optical NELR might be the same multi-phase photoionized plasma. Both X-ray and optical NELR have comparable distances, asymmetric line profiles, and the underlying photoionized plasma is turbulent and compact in size. The X-ray NELR is not the counterpart of the UV/X-ray absorber outside the line of sight because their distances and kinematics are not consistent. In addition, X-ray broad emission features that we find in the spectrum can be accounted for by a third photoionized emission component. The RGS spectrum obtained in 2016 is analyzed as well, where the luminosity of most prominent emission lines (the O VII forbidden line and O VIII Lyα line) are the same (at a 1σ confidence level) as in 2013-2014.

  9. X-ray emission from a nanosecond-pulse discharge in an inhomogeneous electric field at atmospheric pressure

    International Nuclear Information System (INIS)

    Zhang Cheng; Shao Tao; Ren Chengyan; Zhang Dongdong; Tarasenko, Victor; Kostyrya, Igor D.; Ma Hao; Yan Ping

    2012-01-01

    This paper describes experimental studies of the dependence of the X-ray intensity on the anode material in nanosecond high-voltage discharges. The discharges were generated by two nanosecond-pulse generators in atmospheric air with a highly inhomogeneous electric field by a tube-plate gap. The output pulse of the first generator (repetitive pulse generator) has a rise time of about 15 ns and a full width at half maximum of 30–40 ns. The output of the second generator (single pulse generator) has a rise time of about 0.3 ns and a full width at half maximum of 1 ns. The electrical characteristics and the X-ray emission of nanosecond-pulse discharge in atmospheric air are studied by the measurement of voltage-current waveforms, discharge images, X-ray count and dose. Our experimental results showed that the anode material rarely affects electrical characteristics, but it can significantly affect the X-ray density. Comparing the density of X-rays, it was shown that the highest x-rays density occurred in the diffuse discharge in repetitive pulse mode, then the spark discharge with a small air gap, and then the corona discharge with a large air gap, in which the X-ray density was the lowest. Therefore, it could be confirmed that the bremsstrahlung at the anode contributes to the X-ray emission from nanosecond-pulse discharges.

  10. Discovery of the double Doppler-shifted emission-line systems in the X-ray spectrum of SS 433

    Science.gov (United States)

    Kotani, Taro; Kawai, Nobuyuki; Aoki, Takashi; Doty, John; Matsuoka, Masaru; Mitsuda, Kazuhisa; Nagase, Fumiaki; Ricker, George; White, Nick E.

    1994-01-01

    We have used the CCD X-ray spectrometers on ASCA and resolved the X-ray emission line from the jet of SS 433 both into Doppler-shifted components with two distinct velocities, and into emission from different ionization states of iron, i.e., Fe XXV and Fe XXVI. This is the first direct detection of the two Doppler shifted beams in the X-ray spectra of SS 433 and allows the radial velocity of the jet along the line of sight to be determined with an accuracy comparable to the optical spectroscopy. We also found pairs of emission lines from other atomic species, such as ionized silicon and sulfur, with the Doppler shifts consistent with each other. This confirms the origin of the X-ray emission in the high temperature plasma in the jets.

  11. Application of proton-induced X-ray emission method to determination of lead content in blood

    International Nuclear Information System (INIS)

    Slominska, D.; Jarczyk, L.; Rokita, E.; Strzalkowski, A.; Losiowski, A.; Macheta, A.; Sych, M.; Moszkowicz, S.

    1979-01-01

    The proton induced X-ray emission method is applied for determination of lead content in the blood of the people exposed to contact with ethyline vapours and people working in lead-zinc works. (author)

  12. Analysis of borophosphosilicate glass layers on silicon wafers by X-ray emission from photon and electron excitation

    International Nuclear Information System (INIS)

    Elgersma, O.; Borstrok, J.J.M.

    1989-01-01

    Phosphorus and oxygen concentrations in the homogeneous layer of borosilicate glass (BPSG) deposited on Si-integrated circuits are determined by X-ray fluorescence from photon excitation. The X-ray emission from electron excitation in an open X-ray tube instrument yields a sufficiently precise determination of the boron content. The thickness of the layer can be derived from silicon Kα-fluorescence. A calibration model is proposed for photon as well as for electron excitation. The experimentally determined parameters in this model well agree with those derived from fundamental parameters for X-ray absorption and emission. The chemical surrounding of silicon affects strongly the peak profile of the silicon Kβ-emission. This enables to distinguish emission from the silicon atoms in the wafer and from the silicon atoms in the silicon oxide complexes of the BPSG-layer. (author)

  13. Intravenous coronary angiography utilizing K-emission and bremsstrahlung X-rays produced by electron bombardment

    International Nuclear Information System (INIS)

    1992-01-01

    The screening of the general population for coronary artery disease would be practical if a method existed for visualizing the extent of occlusion after an intravenous injection of contrast agent. Measurements performed with synchrotron radiation at SSRL and NSLS have shown that such an intravenous angiography procedure would be possible with an intense source of monochromatic X-rays. Because of the high cost of an electron synchrotron, theoretical analysis and experiments using inanimate phantoms has been undertaken to demonstrate the feasibility of using the spectrum produced by two appropriately chosen anode materials when bombarded with electrons in the 100--500 keV energy range for angiography. By using the X-rays emitted at 120 degree to the incident electron direction, about 20--30% of the X-ray intensity would be due to K-emission lines. Calculations using the TIGERP Monte Carlo Code, have shown that high quality angiograms of human coronary arteries should be possible with a contrast agent containing ytterbium, if an electron beam pulses of 16 kJ were used for each anode target. The experimental program supported in part by the DOE has consisted of these theoretical calculations and experiments at the Dynamitron Electron Accelerator Facility at BNL

  14. A DEEP X-RAY VIEW OF THE BARE AGN ARK 120. I. REVEALING THE SOFT X-RAY LINE EMISSION

    Energy Technology Data Exchange (ETDEWEB)

    Reeves, J. N.; Braito, V. [Center for Space Science and Technology, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250 (United States); Porquet, D. [Observatoire Astronomique de Strasbourg, Université de Strasbourg, CNRS, UMR 7550, 11 rue de l’Université, F-67000 Strasbourg (France); Nardini, E. [Astrophysics Group, School of Physical and Geographical Sciences, Keele University, Keele, Staffordshire, ST5 5BG (United Kingdom); Lobban, A. [Dept of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom); Turner, T. J., E-mail: jreeves@umbc.edu, E-mail: j.n.reeves@keele.ac.uk [Department of Physics, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250 (United States)

    2016-09-10

    The Seyfert 1 galaxy Ark 120 is a prototype example of the so-called class of bare nucleus active galactic nuclei (AGNs), whereby there is no known evidence for the presence of ionized gas along the direct line of sight. Here deep (>400 ks exposure), high-resolution X-ray spectroscopy of Ark 120 is presented from XMM-Newton observations that were carried out in 2014 March, together with simultaneous Chandra /High Energy Transmission Grating exposures. The high-resolution spectra confirmed the lack of intrinsic absorbing gas associated with Ark 120, with the only X-ray absorption present originating from the interstellar medium (ISM) of our own Galaxy, with a possible slight enhancement of the oxygen abundance required with respect to the expected ISM values in the solar neighborhood. However, the presence of several soft X-ray emission lines are revealed for the first time in the XMM-Newton RGS spectrum, associated with the AGN and arising from the He- and H-like ions of N, O, Ne, and Mg. The He-like line profiles of N, O, and Ne appear velocity broadened, with typical FWHMs of ∼5000 km s{sup −1}, whereas the H-like profiles are unresolved. From the clean measurement of the He-like triplets, we deduce that the broad lines arise from a gas of density n {sub e} ∼ 10{sup 11} cm{sup −3}, while the photoionization calculations infer that the emitting gas covers at least 10% of 4 π steradian. Thus the broad soft X-ray profiles appear coincident with an X-ray component of the optical–UV broad-line region on sub-parsec scales, whereas the narrow profiles originate on larger parsec scales, perhaps coincident with the AGN narrow-line region. The observations show that Ark 120 is not intrinsically bare and substantial X-ray-emitting gas exists out of our direct line of sight toward this AGN.

  15. X-ray emission of the hot gas and of accelerated particles in supernova remnants

    International Nuclear Information System (INIS)

    Acero, F.

    2008-09-01

    The current observations seem to support the theory that the shock wave of supernova remnants accelerate electrons (representing about 1% of cosmic rays) of the interstellar medium up to energies of about 10 15 eV. However there is still no solid evidence that supernova remnants also accelerate protons (major component of cosmic rays). The X-ray observations of those supernova remnants with the satellite XMM-Newton can provide crucial information on the acceleration mechanisms and on this population of accelerated particles. This thesis presents the X-ray analysis of the supernova remnants RX J1713.7-3946 and SN 1006 for which it has been shown that they accelerate electrons efficiently. As a result, these objects are very good targets to compare the theoretical models of acceleration to the observation. For the first object, I constructed through new XMM-Newton observations, the first high-angular resolution mosaic of the entire supernova remnant. I then compared the X- and gamma-ray emission of this object in order to understand the nature of the gamma-ray emission. This spectral and morphological comparison allowed me to discuss the two possible origins of the gamma-ray radiation (issued by electrons or by protons). For SN 1006, I studied the density of the ambient medium in which the shock wave propagates. This density is a key parameter for the hydrodynamical evolution of the remnant and for studying a future gamma-ray emission. The study of X-ray emission of the gas heated by the shock wave allowed me to better estimate of the value of the density so far poorly constrained for this object. (author)

  16. The Relation Between Magnetic Fields and X-ray Emission for Solar Microflares and Active Regions

    Science.gov (United States)

    Kirichenko, A. S.; Bogachev, S. A.

    2017-09-01

    We present the result of a comparison between magnetic field parameters and the intensity of X-ray emission for solar microflares with Geosynchronous Operational Environmental Satellites (GOES) classes from A0.02 to B5.1. For our study, we used the monochromatic MgXII Imaging Spectroheliometer (MISH), the Full-disk EUV Telescope (FET), and the Solar PHotometer in X-rays (SphinX) instruments onboard the Complex Orbital Observations Near-Earth of Activity of the Sun-Photon CORONAS- Photon spacecraft because of their high sensitivity in soft X-rays. The peak flare flux (PFF) for solar microflares was found to depend on the strength of the magnetic field and on the total unsigned magnetic flux as a power-law function. In the spectral range 2.8 - 36.6 Å, which shows very little increase related to microflares, the power-law index of the relation between the X-ray flux and magnetic flux for active regions is 1.48 ±0.86, which is close to the value obtained previously by Pevtsov et al. ( Astrophys. J. 598, 1387, 2003) for different types of solar and stellar objects. In the spectral range 1 - 8 Å, the power-law indices for PFF(B) and PFF(Φ) for microflares are 3.87 ±2.16 and 3 ±1.6, respectively. We also make suggestions on the heating mechanisms in active regions and microflares under the assumption of loops with constant pressure and heating using the Rosner-Tucker-Vaiana scaling laws.

  17. Discovery of radio emission from the symbiotic X-ray binary system GX 1+4

    Science.gov (United States)

    van den Eijnden, J.; Degenaar, N.; Russell, T. D.; Miller-Jones, J. C. A.; Wijnands, R.; Miller, J. M.; King, A. L.; Rupen, M. P.

    2018-02-01

    We report the discovery of radio emission from the accreting X-ray pulsar and symbiotic X-ray binary GX 1+4 with the Karl G. Jansky Very Large Array. This is the first radio detection of such a system, wherein a strongly magnetized neutron star accretes from the stellar wind of an M-type giant companion. We measure a 9 GHz radio flux density of 105.3 ± 7.3 μJy, but cannot place meaningful constraints on the spectral index due to a limited frequency range. We consider several emission mechanisms that could be responsible for the observed radio source. We conclude that the observed properties are consistent with shocks in the interaction of the accretion flow with the magnetosphere, a synchrotron-emitting jet, or a propeller-driven outflow. The stellar wind from the companion is unlikely to be the origin of the radio emission. If the detected radio emission originates from a jet, it would show that strong magnetic fields (≥1012 G) do not necessarily suppress jet formation.

  18. A fast search strategy for gravitational waves from low-mass x-ray binaries

    International Nuclear Information System (INIS)

    Messenger, C; Woan, G

    2007-01-01

    We present a new type of search strategy designed specifically to find continuously emitting gravitational wave sources in known binary systems. A component of this strategy is based on the incoherent summation of frequency-modulated binary signal sidebands, a method previously employed in the detection of electromagnetic pulsar signals from radio observations. The search pipeline can be divided into three stages: the first is a wide bandwidth, F-statistic search demodulated for sky position. This is followed by a fast second stage in which areas in frequency space are identified as signal candidates through the frequency domain convolution of the F-statistic with an approximate signal template. For this second stage only precise information on the orbit period and approximate information on the orbital semi-major axis are required a priori. For the final stage we propose a fully coherent Markov chain Monte Carlo based follow-up search on the frequency subspace defined by the candidates identified by the second stage. This search is particularly suited to the low-mass x-ray binaries, for which orbital period and sky position are typically well known and additional orbital parameters and neutron star spin frequency are not. We note that for the accreting x-ray millisecond pulsars, for which spin frequency and orbital parameters are well known, the second stage can be omitted and the fully coherent search stage can be performed. We describe the search pipeline with respect to its application to a simplified phase model and derive the corresponding sensitivity of the search

  19. Hard X-ray emission from accretion shocks around galaxy clusters

    Science.gov (United States)

    Kushnir, Doron; Waxman, Eli

    2010-02-01

    We show that the hard X-ray (HXR) emission observed from several galaxy clusters is consistent with a simple model, in which the nonthermal emission is produced by inverse Compton scattering of cosmic microwave background photons by electrons accelerated in cluster accretion shocks: The dependence of HXR surface brightness on cluster temperature is consistent with that predicted by the model, and the observed HXR luminosity is consistent with the fraction of shock thermal energy deposited in relativistic electrons being lesssim0.1. Alternative models, where the HXR emission is predicted to be correlated with the cluster thermal emission, are disfavored by the data. The implications of our predictions to future HXR observations (e.g. by NuStar, Simbol-X) and to (space/ground based) γ-ray observations (e.g. by Fermi, HESS, MAGIC, VERITAS) are discussed.

  20. Hard X-ray emission from accretion shocks around galaxy clusters

    Energy Technology Data Exchange (ETDEWEB)

    Kushnir, Doron; Waxman, Eli, E-mail: doron.kushnir@weizmann.ac.il, E-mail: eli.waxman@weizmann.ac.il [Physics Faculty, Weizmann Institute of Science, PO Box 26, Rehovot (Israel)

    2010-02-01

    We show that the hard X-ray (HXR) emission observed from several galaxy clusters is consistent with a simple model, in which the nonthermal emission is produced by inverse Compton scattering of cosmic microwave background photons by electrons accelerated in cluster accretion shocks: The dependence of HXR surface brightness on cluster temperature is consistent with that predicted by the model, and the observed HXR luminosity is consistent with the fraction of shock thermal energy deposited in relativistic electrons being ∼<0.1. Alternative models, where the HXR emission is predicted to be correlated with the cluster thermal emission, are disfavored by the data. The implications of our predictions to future HXR observations (e.g. by NuStar, Simbol-X) and to (space/ground based) γ-ray observations (e.g. by Fermi, HESS, MAGIC, VERITAS) are discussed.

  1. Hard X-ray emission from accretion shocks around galaxy clusters

    International Nuclear Information System (INIS)

    Kushnir, Doron; Waxman, Eli

    2010-01-01

    We show that the hard X-ray (HXR) emission observed from several galaxy clusters is consistent with a simple model, in which the nonthermal emission is produced by inverse Compton scattering of cosmic microwave background photons by electrons accelerated in cluster accretion shocks: The dependence of HXR surface brightness on cluster temperature is consistent with that predicted by the model, and the observed HXR luminosity is consistent with the fraction of shock thermal energy deposited in relativistic electrons being ∼<0.1. Alternative models, where the HXR emission is predicted to be correlated with the cluster thermal emission, are disfavored by the data. The implications of our predictions to future HXR observations (e.g. by NuStar, Simbol-X) and to (space/ground based) γ-ray observations (e.g. by Fermi, HESS, MAGIC, VERITAS) are discussed

  2. Einstein Observatory survey of X-ray emission from solar-type stars - the late F and G dwarf stars

    Energy Technology Data Exchange (ETDEWEB)

    Maggio, A.; Sciortino, S.; Vaiana, G.S.; Majer, P.; Bookbinder, J.

    1987-04-01

    Results of a volume-limited X-ray survey of stars of luminosity classes IV and V in the spectral range F7-G9 observed with the Einstein Observatory are presented. Using survival analysis techniques, the stellar X-ray luminosity function in the 0.15-4.0 keV energy band for both single and multiple sources. It is shown that the difference in X-ray luminosity between these two classes of sources is consistent with the superposition of individual components in multiple-component systems, whose X-ray properties are similar to those of the single-component sources. The X-ray emission of the stars in our sample is well correlated with their chromospheric CA II H-K line emission and with their projected equatorial rotational velocity. Comparison of the X-ray luminosity function constructed for the sample of the dG stars of the local population with the corresponding functions derived elsewhere for the Hyades, the Pleiades, and the Orion Ic open cluster confirms that the level of X-ray emission decreases with stellar age. 62 references.

  3. Einstein Observatory survey of X-ray emission from solar-type stars - The late F and G dwarf stars

    Science.gov (United States)

    Maggio, A.; Sciortino, S.; Vaiana, G. S.; Majer, P.; Bookbinder, J.

    1987-01-01

    Results of a volume-limited X-ray survey of stars of luminosity classes IV and V in the spectral range F7-G9 observed with the Einstein Observatory are presented. Using survival analysis techniques, the stellar X-ray luminosity function in the 0.15-4.0 keV energy band for both single and multiple sources. It is shown that the difference in X-ray luminosity between these two classes of sources is consistent with the superposition of individual components in multiple-component systems, whose X-ray properties are similar to those of the single-component sources. The X-ray emission of the stars in our sample is well correlated with their chromospheric CA II H-K line emission and with their projected equatorial rotational velocity. Comparison of the X-ray luminosity function constructed for the sample of the dG stars of the local population with the corresponding functions derived elsewhere for the Hyades, the Pleiades, and the Orion Ic open cluster confirms that the level of X-ray emission decreases with stellar age.

  4. ORIGIN OF THE GALACTIC DIFFUSE X-RAY EMISSION: IRON K-SHELL LINE DIAGNOSTICS

    Energy Technology Data Exchange (ETDEWEB)

    Nobukawa, Masayoshi [Department of Teacher Training and School Education, Nara University of Education, Takabatake-cho, Nara, 630-8528 (Japan); Uchiyama, Hideki [Faculty of Education, Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka, 422-8529 (Japan); Nobukawa, Kumiko K.; Koyama, Katsuji [Department of Physics, Graduate School of Science, Kyoto University, Kitashirakawa-oiwake-cho, Sakyo-ku, Kyoto, 606-8502 (Japan); Yamauchi, Shigeo, E-mail: nobukawa@nara-edu.ac.jp [Department of Physics, Nara Women’s University, Kitauoyanishimachi, Nara, 630-8506 (Japan)

    2016-12-20

    This paper reports detailed K-shell line profiles of iron (Fe) and nickel (Ni) of the Galactic Center X-ray Emission (GCXE), Galactic Bulge X-ray Emission (GBXE), Galactic Ridge X-ray Emission (GRXE), magnetic Cataclysmic Variables (mCVs), non-magnetic Cataclysmic Variables (non-mCVs), and coronally Active Binaries (ABs). For the study of the origin of the GCXE, GBXE, and GRXE, the spectral analysis is focused on equivalent widths of the Fe i-K α , Fe xxv-He α , and Fe xxvi-Ly α  lines. The global spectrum of the GBXE is reproduced by a combination of the mCVs, non-mCVs, and ABs spectra. On the other hand, the GRXE spectrum shows significant data excesses at the Fe i-K α and Fe xxv-He α  line energies. This means that additional components other than mCVs, non-mCVs, and ABs are required, which have symbiotic phenomena of cold gas and very high-temperature plasma. The GCXE spectrum shows larger excesses than those found in the GRXE spectrum at all the K-shell lines of iron and nickel. Among them the largest ones are the Fe i-K α , Fe xxv-He α , Fe xxvi-Ly α , and Fe xxvi-Ly β  lines. Together with the fact that the scale heights of the Fe i-K α , Fe xxv-He α , and Fe xxvi-Ly α lines are similar to that of the central molecular zone (CMZ), the excess components would be related to high-energy activity in the extreme envelopment of the CMZ.

  5. Plasma heating in solar flares and their soft and hard X-ray emissions

    International Nuclear Information System (INIS)

    Falewicz, R.

    2014-01-01

    In this paper, the energy budgets of two single-loop-like flares observed in X-ray are analyzed under the assumption that nonthermal electrons (NTEs) are the only source of plasma heating during all phases of both events. The flares were observed by RHESSI and GOES on 2002 February 20 and June 2, respectively. Using a one-dimensional (1D) hydrodynamic code for both flares, the energy deposited in the chromosphere was derived applying RHESSI observational data. The use of the Fokker-Planck formalism permits the calculation of distributions of the NTEs in flaring loops and thus spatial distributions of the X-ray nonthermal emissions and integral fluxes for the selected energy ranges that were compared with the observed ones. Additionally, a comparative analysis of the spatial distributions of the signals in the RHESSI images was conducted for the footpoints and for all the flare loops in selected energy ranges with these quantities' fluxes obtained from the models. The best compatibility of the model and observations was obtained for the 2002 June 2 event in the 0.5-4 Å GOES range and total fluxes in the 6-12 keV, 12-25 keV, 20-25 keV, and 50-100 keV energy bands. Results of photometry of the individual flaring structures in a high energy range show that the best compliance occurred for the 2002 June 2 flare, where the synthesized emissions were at least 30% higher than the observed emissions. For the 2002 February 20 flare, synthesized emission is about four times lower than the observed one. However, in the low energy range the best conformity was obtained for the 2002 February 20 flare, where emission from the model is about 11% lower than the observed one. The larger inconsistency occurs for the 2002 June 2 solar flare, where synthesized emission is about 12 times greater or even more than the observed emission. Some part of these differences may be caused by inevitable flaws of the applied methodology, like by an assumption that the model of the flare is

  6. Plasma Heating in Solar Flares and their Soft and Hard X-Ray Emissions

    Science.gov (United States)

    Falewicz, R.

    2014-07-01

    In this paper, the energy budgets of two single-loop-like flares observed in X-ray are analyzed under the assumption that nonthermal electrons (NTEs) are the only source of plasma heating during all phases of both events. The flares were observed by RHESSI and GOES on 2002 February 20 and June 2, respectively. Using a one-dimensional (1D) hydrodynamic code for both flares, the energy deposited in the chromosphere was derived applying RHESSI observational data. The use of the Fokker-Planck formalism permits the calculation of distributions of the NTEs in flaring loops and thus spatial distributions of the X-ray nonthermal emissions and integral fluxes for the selected energy ranges that were compared with the observed ones. Additionally, a comparative analysis of the spatial distributions of the signals in the RHESSI images was conducted for the footpoints and for all the flare loops in selected energy ranges with these quantities' fluxes obtained from the models. The best compatibility of the model and observations was obtained for the 2002 June 2 event in the 0.5-4 Å GOES range and total fluxes in the 6-12 keV, 12-25 keV, 20-25 keV, and 50-100 keV energy bands. Results of photometry of the individual flaring structures in a high energy range show that the best compliance occurred for the 2002 June 2 flare, where the synthesized emissions were at least 30% higher than the observed emissions. For the 2002 February 20 flare, synthesized emission is about four times lower than the observed one. However, in the low energy range the best conformity was obtained for the 2002 February 20 flare, where emission from the model is about 11% lower than the observed one. The larger inconsistency occurs for the 2002 June 2 solar flare, where synthesized emission is about 12 times greater or even more than the observed emission. Some part of these differences may be caused by inevitable flaws of the applied methodology, like by an assumption that the model of the flare is

  7. Laboratory measurements of the x-ray line emission from neon-like Fe XVII

    International Nuclear Information System (INIS)

    Brown, G V; Beiersdorfer, P; Chen, H; Scofield, J; Boyce, K R; Kelley, R L; Kilbourne, C A; Porter, F S; Gu, M F; Kahn, S M; Szymkowiak, A E

    2006-01-01

    The authors have conducted a systematic study of the dominant x-ray line emission from Fe XVII. These studies include relative line intensities in the optically thin limit, intensities in the presence of radiation from satellite lines from lower charge states of iron, and the absolute excitation cross sections of some of the strongest lines. These measurements were conducted at the Lawrence Livermore National Laboratory electron beam ion trap facility using crystal spectrometers and a NASA-Goddard Space Flight Center microcalorimeter array

  8. Theoretical progress in studying the characteristic x-ray emission from heavy few-electron ions

    International Nuclear Information System (INIS)

    Surzhykov, Andrey; Stohlker, Thomas; Fritzsche, Stephan; Kabachnik, Nikolai M

    2009-01-01

    Recent theoretical progress in the study of the x-ray characteristic emission from highly-charged, few-electron ions is reviewed. These investigations show that the bound-state radiative transitions in high-Z ions provide a unique tool for better understanding the interplay between the structural and dynamical properties of heavy ions. In order to illustrate such an interplay, detailed calculations are presented for the K α1 decay of the helium-like uranium ions U 90+ following radiative electron capture, Coulomb excitation and dielectronic recombination processes.

  9. Applications of simultaneous ion backscattering and ion-induced x-ray emission

    International Nuclear Information System (INIS)

    Musket, R.G.

    1983-05-01

    Simultaneous ion backscattering and ion-induced x-ray emission (E/sub x/greater than or equal to 300 eV) analyses have been performed using helium ions as probes of the first few hundred nanometers of various materials. These studies serve as a demonstration of the complementary nature of the two types of information obtained. Uncertainties associated with each of the individual techniques were reduced by performing both analyses. The principal advantages of simultaneous analyses over sequential analyses have been delineated

  10. X-ray spectral models of Galactic bulge sources - the emission-line factor

    International Nuclear Information System (INIS)

    Vrtilek, S.D.; Swank, J.H.; Kallman, T.R.

    1988-01-01

    Current difficulties in finding unique and physically meaningful models for the X-ray spectra of Galactic bulge sources are exacerbated by the presence of strong, variable emission and absorption features that are not resolved by the instruments observing them. Nine Einstein solid state spectrometer (SSS) observations of five Galactic bulge sources are presented for which relatively high resolution objective grating spectrometer (OGS) data have been published. It is found that in every case the goodness of fit of simple models to SSS data is greatly improved by adding line features identified in the OGS that cannot be resolved by the SSS but nevertheless strongly influence the spectra observed by SSS. 32 references

  11. Particle induced X-ray emission: a valuable tool for the analysis of metalpoint drawings

    International Nuclear Information System (INIS)

    Duval, A.; Guicharnaud, H.; Dran, J.C.

    2004-01-01

    For several years, we carry out a research on metalpoint drawings, a graphic technique mainly employed by European artists during the 15th and 16th centuries. As a non-destructive and very sensitive analytical technique is required, particle induced X-ray emission (PIXE) analysis with an external beam has been used for this purpose. More than 70 artworks drawn by Italian, Flemish and German artists have been analysed, including leadpoint and silverpoint drawings. Following a short description of the metalpoint technique, the results are compared with the recipes written by Cennino Cennini at the beginning of the 15th century and specific examples are presented

  12. Measurement of anisotropic soft X-ray emission during radio-frequency current drive in the JFT-2M tokamak

    International Nuclear Information System (INIS)

    Kawashima, Hisato; Matoba, Tohru; Hoshino, Katsumichi; Kawakami, Tomohide; Yamamoto, Takumi; Hasegawa, Mitsuru; Fuchs, Gerhard; Uesugi, Yoshihiko.

    1994-01-01

    A new vertical soft X-ray pulse height analyzer (PHA) system and a tangential PHA system were used to measure the anisotropy of soft X-ray emission during lower-hybrid current drive (LHCD) and also during current drive by the combination of LHCD and electron cyclotron resonance heating (ECRH) in the JFT-2M tokamak. The strong soft X-ray emission was measured in the parallel forward direction during LHCD. When ECRH was applied during LHCD, the perpendicular emission was enhanced. The high-energy electron velocity distribution was evaluated by comparing the measured and calculated X-ray spectra. The distribution form was consistent with the theoretical prediction based on the electron Landau damping of lower-hybrid waves and the electron cyclotron damping of electron cyclotron waves for reasonable energy ranges. (author)

  13. 0.5 to 6 MeV Ar ion induced X-ray emission in view to analytical application

    International Nuclear Information System (INIS)

    Tenorio Castilleros, M.D.

    1979-01-01

    A study of the X-ray emission induced by 0.5 to 6 MeV Ar ions has been realized in view of multielemental analytical applications. The historical development of the use of heavy ion induced X-ray emission in analysis and the theoretical background of inner-shell ionization in heavy ion-atom collisions are described. The emission of non characteristic X-rays and the effects related to the penetration of heavy ions in matter are also related. The experimental part contains a description of the experimental devices and of the X-ray spectra fitting method. Thick target yields as a function of the target Z and the Ar ion energy are reported. The analytical possibilities are examined and an application to the analysis of Si and Cl in cadmium telluride crystals is given [fr

  14. Diffuse X-ray emission from Abell clusters 401 and 399 - A gravitationally bound system

    Science.gov (United States)

    Ulmer, M. P.; Kinzer, R.; Cruddace, R. G.; Wood, K.; Evans, W.; Byram, E. T.; Chubb, T. A.; Friedman, H.

    1979-01-01

    The X-ray emission from the Abell 401-399 region has been studied using data obtained by the A-1 proportional counter aboard HEAO 1 in two different ways. The first involved routine scanning of the region during the all-sky survey, and the second was an observation in which the instrument was pointed at A401 during a lunar occultation. The emission is shown to be unusually extended and to be centered on a point lying between A401 and A399. The best fit of a uniform disk model to the data yielded a radius of 25.5 + or -4.4 arcmin for the lunar occultation and 42 + or - 17 arcmin for the scans. A possible explanation of the results is that A401 and A399 are both diffuse cluster X-ray sources. Alternatively, the emission may come from a large gas cloud of at least 10 to the 15th solar masses enveloping both clusters.

  15. Electronic structure of human hemoglobin: ultrasoft X-ray emission study

    International Nuclear Information System (INIS)

    Soldatov, A.V.; Kravtsova, A.N.; Fedorovich, E.N.; Kurmaev, E.Z.; Moewes, A.

    2004-01-01

    Full text: The iron L 2,3 and carbon, nitrogen and oxygen Kα X-ray emission spectra (XES) of human hemoglobin have been recorded at the soft X-ray spectroscopy endstation on Undulator Beam line 8.0 at Advanced Light Source (ALS) located at the Lawrence Berkeley National Laboratory. The theoretical calculations of Fe L 3 -XES have been performed using ab initio code FEFF8.2. The calculations have been carried out for the structure of hemoglobin presented in PDB (entry 3HHB) as well as for the molecule with symmetrical heme plane. It was found that the Fe L 3 emission spectrum calculated for the ideal molecule agrees slightly better with the experiment as compared with those calculated for the real molecule. Thus, one can use the structure of the ideal molecule for theoretical Fe L 3 -XES simulations. The theoretical analysis has shown that the fist peak of experimental Fe L 3 - emission spectrum is enhanced by the nearest nitrogen atoms lying in heme plane around the central iron atom. The theoretical C K- and N K-XES spectra of hemoglobin have been calculated. A good agreement between theoretical and experimental spectra has been obtained. The distribution of the partial electronic densities of states in the valence and conduction bands of hemoglobin has been determined

  16. Measurement of X-ray emission efficiency for K-lines.

    Science.gov (United States)

    Procop, M

    2004-08-01

    Results for the X-ray emission efficiency (counts per C per sr) of K-lines for selected elements (C, Al, Si, Ti, Cu, Ge) and for the first time also for compounds and alloys (SiC, GaP, AlCu, TiAlC) are presented. An energy dispersive X-ray spectrometer (EDS) of known detection efficiency (counts per photon) has been used to record the spectra at a takeoff angle of 25 degrees determined by the geometry of the secondary electron microscope's specimen chamber. Overall uncertainty in measurement could be reduced to 5 to 10% in dependence on the line intensity and energy. Measured emission efficiencies have been compared with calculated efficiencies based on models applied in standardless analysis. The widespread XPP and PROZA models give somewhat too low emission efficiencies. The best agreement between measured and calculated efficiencies could be achieved by replacing in the modular PROZA96 model the original expression for the ionization cross section by the formula given by Casnati et al. (1982) A discrepancy remains for carbon, probably due to the high overvoltage ratio.

  17. First light - II. Emission line extinction, population III stars, and X-ray binaries

    Science.gov (United States)

    Barrow, Kirk S. S.; Wise, John H.; Aykutalp, Aycin; O'Shea, Brian W.; Norman, Michael L.; Xu, Hao

    2018-02-01

    We produce synthetic spectra and observations for metal-free stellar populations and high-mass X-ray binaries in the Renaissance Simulations at a redshift of 15. We extend our methodology from the first paper in the series by modelling the production and extinction of emission lines throughout a dusty and metal-enriched interstellar and circum-galactic media extracted from the simulation, using a Monte Carlo calculation. To capture the impact of high-energy photons, we include all frequencies from hard X-ray to far-infrared with enough frequency resolution to discern line emission and absorption profiles. The most common lines in our sample in order of their rate of occurrence are Ly α, the C IV λλ1548, 1551 doublet, H α, and the Ca II λλλ8498, 8542, 8662 triplet. The best scenario for a direct observation of a metal-free stellar population is a merger between two Population III Galaxies. In mergers between metal-enriched and metal-free stellar populations, some characteristics may be inferred indirectly. Single Population III galaxies are too dim to be observed photometrically at z = 15. Ly α emission is discernible by JWST as an increase in J200w - J277w colour off the intrinsic stellar tracks. Observations of metal-free stars will be difficult, though not impossible, with the next generation of space telescopes.

  18. Millimeter and X-Ray Emission from the 5 July 2012 Solar Flare

    Science.gov (United States)

    Tsap, Y. T.; Smirnova, V. V.; Motorina, G. G.; Morgachev, A. S.; Kuznetsov, S. A.; Nagnibeda, V. G.; Ryzhov, V. S.

    2018-03-01

    The 5 July 2012 solar flare SOL2012-07-05T11:44 (11:39 - 11:49 UT) with an increasing millimeter spectrum between 93 and 140 GHz is considered. We use space and ground-based observations in X-ray, extreme ultraviolet, microwave, and millimeter wave ranges obtained with the Reuven Ramaty High-Energy Solar Spectroscopic Imager, Solar Dynamics Observatory (SDO), Geostationary Operational Environmental Satellite, Radio Solar Telescope Network, and Bauman Moscow State Technical University millimeter radio telescope RT-7.5. The main parameters of thermal and accelerated electrons were determined through X-ray spectral fitting assuming the homogeneous thermal source and thick-target model. From the data of the Atmospheric Imaging Assembly/SDO and differential-emission-measure calculations it is shown that the thermal coronal plasma gives a negligible contribution to the millimeter flare emission. Model calculations suggest that the observed increase of millimeter spectral flux with frequency is determined by gyrosynchrotron emission of high-energy (≳ 300 keV) electrons in the chromosphere. The consequences of the results are discussed in the light of the flare-energy-release mechanisms.

  19. A fast pulse phase estimation method for X-ray pulsar signals based on epoch folding

    Directory of Open Access Journals (Sweden)

    Xue Mengfan

    2016-06-01

    Full Text Available X-ray pulsar-based navigation (XPNAV is an attractive method for autonomous deep-space navigation in the future. The pulse phase estimation is a key task in XPNAV and its accuracy directly determines the navigation accuracy. State-of-the-art pulse phase estimation techniques either suffer from poor estimation accuracy, or involve the maximization of generally non-convex object function, thus resulting in a large computational cost. In this paper, a fast pulse phase estimation method based on epoch folding is presented. The statistical properties of the observed profile obtained through epoch folding are developed. Based on this, we recognize the joint probability distribution of the observed profile as the likelihood function and utilize a fast Fourier transform-based procedure to estimate the pulse phase. Computational complexity of the proposed estimator is analyzed as well. Experimental results show that the proposed estimator significantly outperforms the currently used cross-correlation (CC and nonlinear least squares (NLS estimators, while significantly reduces the computational complexity compared with NLS and maximum likelihood (ML estimators.

  20. HARD X-RAY AND MICROWAVE EMISSIONS FROM SOLAR FLARES WITH HARD SPECTRAL INDICES

    Energy Technology Data Exchange (ETDEWEB)

    Kawate, T. [Kwasan and Hida Observatory, Kitashirakawa-oiwakecho, Sakyo, Kyoto 606-8502 (Japan); Nishizuka, N. [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 229-8510 (Japan); Oi, A. [College of Science, Ibaraki University, Mito, Ibaraki 310-8512 (Japan); Ohyama, M. [Faculty of Education, Shiga University, 2-5-1 Hiratsu, Otsu, Shiga 1-1, Baba Hikone city, Siga 522-8522 (Japan); Nakajima, H., E-mail: kawate@kusastro.kyoto-u.ac.jp [Nobeyama Solar Radio Observatory, NAOJ, Nobeyama, Minamisaku, Nagano 384-1305 (Japan)

    2012-03-10

    We analyze 10 flare events that radiate intense hard X-ray (HXR) emission with significant photons over 300 keV to verify that the electrons that have a common origin of acceleration mechanism and energy power-law distribution with solar flares emit HXRs and microwaves. Most of these events have the following characteristics. HXRs emanate from the footpoints of flare loops, while microwaves emanate from the tops of flare loops. The time profiles of the microwave emission show delays of peak with respect to those of the corresponding HXR emission. The spectral indices of microwave emissions show gradual hardening in all events, while the spectral indices of the corresponding HXR emissions are roughly constant in most of the events, though rather rapid hardening is simultaneously observed in some for both indices during the onset time and the peak time. These characteristics suggest that the microwave emission emanates from the trapped electrons. Then, taking into account the role of the trapping of electrons for the microwave emission, we compare the observed microwave spectra with the model spectra calculated by a gyrosynchrotron code. As a result, we successfully reproduce the eight microwave spectra. From this result, we conclude that the electrons that have a common acceleration and a common energy distribution with solar flares emit both HXR and microwave emissions in the eight events, though microwave emission is contributed to by electrons with much higher energy than HXR emission.

  1. Fast electron and X-ray scattering as a tool to study target's structure

    International Nuclear Information System (INIS)

    Amusia, M.Ya.

    2007-01-01

    We concentrate on several relatively new aspects of the study of fast electron and X-ray scattering by atoms and atom-like objects, namely endohedral atoms and fullerenes. However, main attention is given to fast charge particle scattering. We show that the corresponding cross-sections, being expressed via so-called generalized oscillator strengths (GOS), give information on the electronic structure of the target and on the role of electron correlations in it. We consider what sort of information became available when analyzing the dependence of GOS upon their multipolarity, transferred momentum q and energy ω. To obtain theoretical results, we employ both the one-electron Hartree-Fock approximation and account for the multi-electron correlation in the target, using the random phase approximation with exchange. We demonstrate the role of non-dipole corrections in the small-angle fast-electron inelastic scattering. There dipole contribution dominates while non-dipole corrections can be considerably and controllably enhanced as compared to the case of low and medium energy photoionization. We show also that analyses of GOS for discrete level excitations permit to clarify their multipolarity. The results of calculations of Compton excitation and ionization cross-sections are presented. Attention is given to cooperative effects in inelastic fast electron-atom scattering that results in directed motion of the secondary electrons, a phenomenon that is similar to 'drag currents' in photoionization. We demonstrate how one should derive GOS for endohedral atoms, e.g. A-C 60 and what is the additional information that can be obtained from corresponding GOS. Most of discussions are illustrated by the results of concrete calculations

  2. Spectral modeling of the charge-exchange X-ray emission from M82

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Shuinai; Ji, Li; Zhou, Xin [Purple Mountain Observatory, CAS, Nanjing 210008 (China); Wang, Q. Daniel [Astronomy Department, University of Massachusetts, Amherst, MA 01003 (United States); Smith, Randall K.; Foster, Adam R., E-mail: snzhang@pmo.ac.cn [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)

    2014-10-10

    It has been proposed that the charge-exchange (CX) process at the interface between hot and cool interstellar gases could contribute significantly to the observed soft X-ray emission in star-forming galaxies. We analyze the XMM-Newton/reflection grating spectrometer (RGS) spectrum of M82 using a newly developed CX model combined with a single-temperature thermal plasma to characterize the volume-filling hot gas. The CX process is largely responsible for not only the strongly enhanced forbidden lines of the Kα triplets of various He-like ions but also good fractions of the Lyα transitions of C VI (∼87%), O VIII, and N VII (≳50%) as well. In total about a quarter of the X-ray flux in the RGS 6-30 Å band originates in the CX. We infer an ion incident rate of 3 × 10{sup 51} s{sup –1} undergoing CX at the hot and cool gas interface and an effective area of the interface of ∼2 × 10{sup 45} cm{sup 2} that is one order of magnitude larger than the cross section of the global biconic outflow. With the CX contribution accounted for, the best-fit temperature of the hot gas is 0.6 keV, and the metal abundances are approximately solar. We further show that the same CX/thermal plasma model also gives an excellent description of the EPIC-pn spectrum of the outflow Cap, projected at 11.6 kpc away from the galactic disk of M82. This analysis demonstrates that the CX is potentially an important contributor to the X-ray emission from starburst galaxies and also an invaluable tool to probe the interface astrophysics.

  3. High resolution X-ray emission spectroscopy: An advanced tool for actinide research

    Science.gov (United States)

    Vitova, T.; Brendebach, B.; Dardenne, K.; Denecke, M. A.; Lebid, A.; Löble, M.; Rothe, J.; Batuk, O. N.; Hormes, J.; Liu, D.; Breher, F.; Geckeis, H.

    2010-03-01

    High resolution X-ray emission spectroscopy (HRXES) is becoming increasingly important for our understanding of electronic and coordination structures. The combination of such information with development of quantum theoretical tools will advance our capability for predicting reactivity and physical behavior especially of 5f elements. HRXES can be used to remove lifetime broadening by registering the partial fluorescence yield emitted by the sample (i.e., recording a windowed signal from the energy dispersed fluorescence emission while varying incident photon energy), thereby yielding highly resolved X-ray absorption fine structure (XAFS) spectra. Such spectra often display resonant features not observed in conventional XAFS. The spectrometer set-up can also be used for a wide range of other experiments, for example, resonant inelastic X-ray scattering (RIXS), where bulk electron configuration information in solids, liquids and gases is obtained. Valence-selective XAFS studies, where the local structure of a selected element's valence state present in a mixture of valence states can be obtained, as well as site-selective XAFS studies, where the coordination structure of a metal bound to selected elements can be differentiated from that of all the other ligating atoms. A HRXES spectrometer has been constructed and is presently being commissioned for use at the INE-Beamline for actinide research at the synchrotron source ANKA at FZK. We present the spectrometer's compact, modular design, optimized for attaining a wide range of energies, and first test measurement results. Examples from HRXES studies of lanthanides, actinides counter parts, are also shown.

  4. Studies of the Hard X-ray Emission from the Filippov Type Plasma Focus Device, Dena

    Science.gov (United States)

    Tafreshi, M. A.; Saeedzadeh, E.

    2006-12-01

    This article is about the characteristics of the hard X-ray (HXR) emission from the Filippov type plasma focus (PF) device, Dena. The article begins with a brief presentation of Dena, and the mechanism of the HXR production in PF devices. Then using the differential absorption spectrometry, the energy resolved spectrum of the HXR emission from a 37 kJ discharge in Dena, is estimated. The energy flux density and the energy fluence of this emission have also been calculated to be 1.9 kJ cm-2 s-1 and 9.4 × 10-5 J cm-2. In the end, after presentation of radiography of sheep bones and calf ribs, the medical application of the PF devices has been discussed.

  5. X-ray emission in heavy-ion collisions. Progress report, March 1, 1982-March 1, 1983

    International Nuclear Information System (INIS)

    Watson, R.L.

    1983-03-01

    A major project involving the study of electron transfer in fluorine compounds following multiple K-plus L-shell ionization by 5.5 MeV He, 22 MeV C, 48 MeV Mg, and 80 MeV Ar ions was completed. This comprehensive investigation, which began three years ago, uncovered a resonant electron transfer mechanism, provided the first quantitative estimates of electron transfer rates, and revealed the importance of fast electron transfer to n greater than or equal to 3 states in solid compounds. Considerable progress was made in delineating the effects of solid state environment on x-ray emission from highly stripped projectile ions. A surprising result in this project area was the discovery of lines associated with states involving n = 3 electrons in 48 MeV Mg projectile x-ray spectra obtained with thick carbon targets. Work was completed on a study of the alignment of foil-excited H- and He-like states in 65 MeV sulfur ions. These measurements are being extended to Magnesium ions with the intention of searching for surface and tilted foil effects. The report contains a summary of the research activities supported by this contract during the 1981 to 1982 contract year

  6. Physiologically gated microbeam radiation using a field emission x-ray source array

    Energy Technology Data Exchange (ETDEWEB)

    Chtcheprov, Pavel, E-mail: PavelC@unc.edu, E-mail: zhou@email.unc.edu [Department of Biomedical Engineering, University of North Carolina, 152 MacNider Hall, Campus Box 7575, Chapel Hill, North Carolina 27599 (United States); Burk, Laurel; Inscoe, Christina; Ger, Rachel; Hadsell, Michael; Lu, Jianping [Department of Physics and Astronomy, University of North Carolina, Phillips Hall, CB #3255, 120 East Cameron Avenue, Chapel Hill, North Carolina 27599 (United States); Yuan, Hong [Department of Radiology, University of North Carolina, 2006 Old Clinic, CB #7510, Chapel Hill, North Carolina 27599 (United States); Zhang, Lei [Department of Applied Physical Sciences, University of North Carolina, Chapman Hall, CB#3216, Chapel Hill, North Carolina 27599 (United States); Chang, Sha [Department of Radiation Oncology, University of North Carolina, 101 Manning Drive, Chapel Hill, North Carolina 27514 and UNC Lineberger Comprehensive Cancer Center, University of North Carolina, 101 Manning Drive, Chapel Hill, North Carolina 27514 (United States); Zhou, Otto, E-mail: PavelC@unc.edu, E-mail: zhou@email.unc.edu [Department of Physics and Astronomy, University of North Carolina, Phillips Hall, CB #3255, 120 East Cameron Avenue, Chapel Hill, North Carolina 27599 and UNC Lineberger Comprehensive Cancer Center, University of North Carolina, 101 Manning Drive, Chapel Hill, North Carolina 27514 (United States)

    2014-08-15

    Purpose: Microbeam radiation therapy (MRT) uses narrow planes of high dose radiation beams to treat cancerous tumors. This experimental therapy method based on synchrotron radiation has been shown to spare normal tissue at up to 1000 Gy of peak entrance dose while still being effective in tumor eradication and extending the lifetime of tumor-bearing small animal models. Motion during treatment can lead to significant movement of microbeam positions resulting in broader beam width and lower peak to valley dose ratio (PVDR), which reduces the effectiveness of MRT. Recently, the authors have demonstrated the feasibility of generating microbeam radiation for small animal treatment using a carbon nanotube (CNT) x-ray source array. The purpose of this study is to incorporate physiological gating to the CNT microbeam irradiator to minimize motion-induced microbeam blurring. Methods: The CNT field emission x-ray source array with a narrow line focal track was operated at 160 kVp. The x-ray radiation was collimated to a single 280 μm wide microbeam at entrance. The microbeam beam pattern was recorded using EBT2 Gafchromic{sup ©} films. For the feasibility study, a strip of EBT2 film was attached to an oscillating mechanical phantom mimicking mouse chest respiratory motion. The servo arm was put against a pressure sensor to monitor the motion. The film was irradiated with three microbeams under gated and nongated conditions and the full width at half maximums and PVDRs were compared. An in vivo study was also performed with adult male athymic mice. The liver was chosen as the target organ for proof of concept due to its large motion during respiration compared to other organs. The mouse was immobilized in a specialized mouse bed and anesthetized using isoflurane. A pressure sensor was attached to a mouse's chest to monitor its respiration. The output signal triggered the electron extraction voltage of the field emission source such that x-ray was generated only

  7. The response of mouse skin to re-irradiation with x-rays or fast neutrons

    International Nuclear Information System (INIS)

    Tsukiyama, Iwao; Egawa, Sunao; Kumazawa, Akiyoshi; Iino, Yuu.

    1986-01-01

    Effects of neutrons and x-rays on mouse skin which had been previously irradiated with x-rays were investigated. Two tattoo marks were placed in the hairless legs of mice at intervals of 15 mm. The legs were exposed to various doses of x-ray and neutrons to determine the relative biological effectiveness (RBE) using the contraction of the skin as an index. The RBE was 0.93 - 1.73. The legs of the mice were preexposed to 25 Gy of x-ray, and exposed 4 months later. The contraction of the skin began earlier than after the first irradiation. RBE was 2.18 - 2.47. This RBE was higher than that in untreated mice. These results suggest that previously irradiated normal tissues are much more sensitive to neutrons than to x-rays. (author)

  8. A final report to the Laboratory Directed Research and Development committee on Project 93-ERP-075: ''X-ray laser propagation and coherence: Diagnosing fast-evolving, high-density laser plasmas using X-ray lasers''

    International Nuclear Information System (INIS)

    Wan, A.S.; Cauble, R.; Da Silva, L.B.; Libby, S.B.; Moreno, J.C.

    1996-02-01

    This report summarizes the major accomplishments of this three-year Laboratory Directed Research and Development (LDRD) Exploratory Research Project (ERP) entitled ''X-ray Laser Propagation and Coherence: Diagnosing Fast-evolving, High-density Laser Plasmas Using X-ray Lasers,'' tracking code 93-ERP-075. The most significant accomplishment of this project is the demonstration of a new laser plasma diagnostic: a soft x-ray Mach-Zehnder interferometer using a neonlike yttrium x-ray laser at 155 angstrom as the probe source. Detailed comparisons of absolute two-dimensional electron density profiles obtained from soft x-ray laser interferograms and profiles obtained from radiation hydrodynamics codes, such as LASNEX, will allow us to validate and benchmark complex numerical models used to study the physics of laser-plasma interactions. Thus the development of soft x-ray interferometry technique provides a mechanism to probe the deficiencies of the numerical models and is an important tool for, the high-energy density physics and science-based stockpile stewardship programs. The authors have used the soft x-ray interferometer to study a number of high-density, fast evolving, laser-produced plasmas, such as the dynamics of exploding foils and colliding plasmas. They are pursuing the application of the soft x-ray interferometer to study ICF-relevant plasmas, such as capsules and hohlraums, on the Nova 10-beam facility. They have also studied the development of enhanced-coherence, shorter-pulse-duration, and high-brightness x-ray lasers. The utilization of improved x-ray laser sources can ultimately enable them to obtain three-dimensional holographic images of laser-produced plasmas

  9. X-ray emission from a high-atomic-number z-pinch plasma created from compact wire arrays

    International Nuclear Information System (INIS)

    Sanford, T.W.L.; Mosher, D.; De Groot, J.S.

    1996-01-01

    Thermal and nonthermal x-ray emission from the implosion of compact tungsten wire arrays in 5-MA Saturn discharges is reported. The timing of multiple implosions and the thermal x-ray spectra (1 to 10 keV) agree with 2D radiation-hydrocode simulations. Nonthermal x-ray emission (10 to 100 keV) correlates with pinch spots distributed along the z-axis. The similarities of the measured nonthermal spectrum, yield, and pinch-spot emission with those of 0.8-MA, single-exploded-wire discharges on Gamble-II suggest a common nonthermal-production mechanism. Nonthermal x-ray yields are lower than expected from current scaling of Gamble II results, suggesting that implosion geometries are not as efficient as single-wire geometries for nonthermal x-ray production. The instabilities, azimuthal asymmetries, and inferred multiple implosions that accompany the implosion geometry lead to larger, more irregular pinch spots, a likely reason for reduced nonthermal efficiency. A model for nonthermal-electron acceleration across magnetic fields in highly-collisional, high-atomic-number plasmas combined with 1D hydrocode simulations of Saturn compact loads predicts weak nonthermal x-ray emission. (author). 3 figs., 10 refs

  10. X-ray emission from a high-atomic-number z-pinch plasma created from compact wire arrays

    International Nuclear Information System (INIS)

    Sanford, T.W.L.; Mosher, D.; De Groot, J.S.

    1996-01-01

    Thermal and nonthermal x-ray emission from the implosion of compact tungsten wire arrays in 5-MA Saturn discharges is reported. The timing of multiple implosions and the thermal x-ray spectra (1 to 10 keV) agree with 2D radiation-hydrocode simulations. Nonthermal x-ray emission (10 to 100 keV) correlates with pinch spots distributed along the z-axis. The similarities of the measured nonthermal spectrum, yield, and pinch-spot emission with those of 0.8-MA, single- exploded-wire discharges on Gamble-II suggest a common nonthermal- production mechanism. Nonthermal x-ray yields are lower than expected from current scaling of Gamble II results, suggesting that implosion geometries are not as efficient as single-wire geometries for nonthermal x-ray production. The instabilities, azimuthal asymmetries, and inferred multiple implosions that accompany the implosion geometry lead to larger, more irregular pinch spots, a likely reason for reduced nonthermal efficiency. A model for nonthermal-electron acceleration across magnetic fields in highly- collisional, high-atomic-number plasmas combined with 1D hydrocode simulations of Saturn compact loads predicts weak nonthermal x-ray emission

  11. Solar Coronal Events with Extended Hard X-ray and Gamma-ray Emission

    Science.gov (United States)

    Hudson, H. S.

    2017-12-01

    A characteristic pattern of solar hard X-ray emission, first identified in SOL1969-03-31 by Frost & Dennis (1971) now has been linked to prolonged high-energy gamma-ray emission detected by the Fermi/LAT experiment, for example in SOL2014-09-01. The distinctive features of these events include flat hard X-ray spectra extending well above 100 keV, a characteristic pattern of time development, low-frequency gyrosynchrotron peaks, CME association, and gamma-rays identifiable with pion decay originating in GeV ions. The identification of these events with otherwise known solar structures nevertheless remains elusive, in spite of the wealth of imagery available from AIA. The quandary is that these events have a clear association with CMEs in the high corona, and yet the gamma-ray production implicates the photosphere itself. The vanishingly small loss cone in the nominal acceleration region makes this extremely difficult. I propose direct inward advection of a part of the SEP particle population, as created on closed field structures, as a possible resolution of this puzzle, and note that this requires retracting magnetic structures on long time scales following the flare itself.

  12. X-ray emission on hybird stars: ROSAT observations of alpha Trianguli Australis and iota Aurigae

    Science.gov (United States)

    Kashyap, V.; Rosner, R.; Harnden, F. R., Jr.; Maggio, A.; Micela, G.; Sciortino, S.

    1994-01-01

    We report on deep ROSAT observations of two Hybrid atmosphere stars, alpha TrA and iota Aur, and our analysis of these observations. We detect high-energy transient phenomena on alpha TrA and consider the implications of this discovery to the atmospheres of Hybrid stars. We detect iota Aur in the high-energy passband of ROSAT, implying the existence of multimillion degree plasma on the star. Our major results include the following: discovery of two large flare events, detected during pointed observations of alpha TrA; the demonstration that the flare emission most likely comes from the giant itself, rather than from a previously unseen low-mass companion star; the demonstration that the plasma characteristics associated with the flares and with the 'quiescent' component are essentially indistinguishable; and that the geometric dimensions of the emitting plasma are considerably smaller than the critical dimension characterizing stable 'hot' coronal loop structures. Our results suggest that alpha TrA does not have any steady X-ray emission consistent with theoretical expectations, and support the argument that Hybrid stars constitute a transitional type of object in which large-scale magnetic dynamo activity ceases, and the dominant spatial scales characterizing coronal structure rapidly decline as such stars evolve across the X-ray 'Dividing Line' in the H-R diagram.

  13. Wind-embedded shocks in FASTWIND: X-ray emission and K-shell absorption

    Science.gov (United States)

    Carneiro, L. P.; Puls, J.; Sundqvist, J. O.; Hoffmann, T. L.

    2017-11-01

    EUV and X-ray radiation emitted from wind-embedded shocks can affect the ionization balance in the outer atmospheres of massive stars, and can also be the mechanism responsible for producing highly ionized atoms detected in the wind UV spectra. To investigate these processes, we implemented the emission from wind-embedded shocks and related physics into our atmosphere/spectrum synthesis code FASTWIND. We also account for the high energy absorption of the cool wind, by adding important K-shell opacities. Various tests justfying our approach have been described by Carneiro+(2016, A&A 590, A88). In particular, we studied the impact of X-ray emission on the ionization balance of important elements. In almost all the cases, the lower ionization stages (O iv, N iv, P v) are depleted and the higher stages (N v, O v, O vi) become enhanced. Moreover, also He lines (in particular He ii 1640 and He ii 4686) can be affected as well. Finally, we carried out an extensive discussion of the high-energy mass absorption coefficient, κν, regarding its spatial variation and dependence on T eff. We found that (i) the approximation of a radially constant κν can be justified for r >= 1.2R * and λ <= 18 Å, and also for many models at longer wavelengths. (ii) In order to estimate the actual value of this quantity, however, the He ii background needs to be considered from detailed modeling.

  14. Applications of X-ray Computed Tomography and Emission Computed Tomography

    International Nuclear Information System (INIS)

    Seletchi, Emilia Dana; Sutac, Victor

    2005-01-01

    Computed Tomography is a non-destructive imaging method that allows visualization of internal features within non-transparent objects such as sedimentary rocks. Filtering techniques have been applied to circumvent the artifacts and achieve high-quality images for quantitative analysis. High-resolution X-ray computed tomography (HRXCT) can be used to identify the position of the growth axis in speleothems by detecting subtle changes in calcite density between growth bands. HRXCT imagery reveals the three-dimensional variability of coral banding providing information on coral growth and climate over the past several centuries. The Nuclear Medicine imaging technique uses a radioactive tracer, several radiation detectors, and sophisticated computer technologies to understand the biochemical basis of normal and abnormal functions within the brain. The goal of Emission Computed Tomography (ECT) is to accurately determine the three-dimensional radioactivity distribution resulting from the radiopharmaceutical uptake inside the patient instead of the attenuation coefficient distribution from different tissues as obtained from X-ray Computer Tomography. ECT is a very useful tool for investigating the cognitive functions. Because of the low radiation doses associated with Positron Emission Tomography (PET), this technique has been applied in clinical research, allowing the direct study of human neurological diseases. (authors)

  15. Absolute Soft X-ray Emission Measurements at the Nike Laser

    Science.gov (United States)

    Weaver, J.; Atkin, R.; Boyer, C.; Colombant, D.; Feldman, U.; Fielding, D.; Gardner, J.; Holland, G.; Klapisch, M.; Mostovych, A. N.; Obenscain, S.; Seely, J. F.

    2002-11-01

    Recent experiments at the Nike laser facility have demonstrated that, when a low intensity prepulse ( 2main laser intensity) is used to heat a thin Au or Pd coating on a planar CH target, the growth of non-uniformities due to laser imprint can be reduced from the growth observed for an uncoated CH target. The absolute radiation intensity in the soft x-ray region (0.1-1 keV) has a important role in the energy balance for layered targets. There is an ongoing effort to characterize the soft x-ray emission using an absolutely calibrated transmission grating spectrometer and filtered diode modules. Measurements of the angular distribution of the emission from unlayered solid targets (Au, Pd, CH) have recently been made using an array of moveable filtered diode modules. The data from the angular distribution studies will be presented. A new absolutely calibrated, time-resolving transmission grating spectrometer has been installed at the Nike. The new version has improved spectral resolution, selectable transmission filters, and the potential for simultaneous temporal, spatial, and spectral resolution. Preliminary data from the new spectrometer will be presented and future experiments will be briefly discussed. *Work was supported by DoE

  16. Optical and x-ray imaging of electron beams using synchrotron emission

    International Nuclear Information System (INIS)

    Wilke, M.

    1995-01-01

    In the case of very low emittance electron and positron storage ring beams, it is impossible to make intrusive measurements of beam properties without increasing the emittance and possibly disrupting the beam. In cases where electron or positron beams have high average power densities (such as free electron laser linacs), intrusive probes such as wires and optical transition radiation screens or Cherenkov emitting screens can be easily damaged or destroyed. The optical and x-ray emissions from the bends in the storage rings and often from linac bending magnets can be used to image the beam profile to obtain emittance information about the beam. The techniques, advantages and limitations of using both optical and x-ray synchrotron emission to measure beam properties are discussed and the possibility of single bunch imaging is considered. The properties of suitable imagers and converters such as phosphors are described. Examples of previous, existing and planned applications are given where available, including a pinhole imaging system currently being designed for the Advanced Photon Source at Argonne National Laboratory

  17. Optical and x-ray imaging of electron beams using synchrotron emission

    International Nuclear Information System (INIS)

    Wilke, M.D.

    1994-01-01

    In the case of very low eniittance electron and positron storage ring beams, it is impossible to make intrusive measurements of beam properties without increasing the emittance and possibly disrupting the beam. In cases where electron or positron beams have high average power densities (such as free electron laser linacs), intrusive probes such as wires and optical transition radiation screens or Cherenkov emitting screens can be easily damaged or destroyed. The optical and x-ray emissions from the bends in the storage rings and often from linac bending magnets can be used to image the beam profile to obtain emittance information about the beam. The techniques, advantages and limitations of using both optical and x-ray synchrotron emission to measure beam properties are discussed and the possibility of single bunch imaging is considered. The properties of suitable imagers and converters such as phosphors are described. Examples of previous, existing and planned applications are given where available, including a pinhole imaging system currently being designed for the Advanced Photon Source at Argonne National Laboratory

  18. Fast automatic segmentation of anatomical structures in x-ray computed tomography images to improve fluorescence molecular tomography reconstruction.

    Science.gov (United States)

    Freyer, Marcus; Ale, Angelique; Schulz, Ralf B; Zientkowska, Marta; Ntziachristos, Vasilis; Englmeier, Karl-Hans

    2010-01-01

    The recent development of hybrid imaging scanners that integrate fluorescence molecular tomography (FMT) and x-ray computed tomography (XCT) allows the utilization of x-ray information as image priors for improving optical tomography reconstruction. To fully capitalize on this capacity, we consider a framework for the automatic and fast detection of different anatomic structures in murine XCT images. To accurately differentiate between different structures such as bone, lung, and heart, a combination of image processing steps including thresholding, seed growing, and signal detection are found to offer optimal segmentation performance. The algorithm and its utilization in an inverse FMT scheme that uses priors is demonstrated on mouse images.

  19. Fast X-ray powder diffraction on I11 at Diamond.

    Science.gov (United States)

    Thompson, Stephen P; Parker, Julia E; Marchal, Julien; Potter, Jonathan; Birt, Adrian; Yuan, Fajin; Fearn, Richard D; Lennie, Alistair R; Street, Steven R; Tang, Chiu C

    2011-07-01

    The commissioning and performance characterization of a position-sensitive detector designed for fast X-ray powder diffraction experiments on beamline I11 at Diamond Light Source are described. The detecting elements comprise 18 detector-readout modules of MYTHEN-II silicon strip technology tiled to provide 90° coverage in 2θ. The modules are located in a rigid housing custom designed at Diamond with control of the device fully integrated into the beamline data acquisition environment. The detector is mounted on the I11 three-circle powder diffractometer to provide an intrinsic resolution of Δ2θ approximately equal to 0.004°. The results of commissioning and performance measurements using reference samples (Si and AgI) are presented, along with new results from scientific experiments selected to demonstrate the suitability of this facility for powder diffraction experiments where conventional angle scanning is too slow to capture rapid structural changes. The real-time dehydrogenation of MgH(2), a potential hydrogen storage compound, is investigated along with ultrafast high-throughput measurements to determine the crystallite quality of different samples of the metastable carbonate phase vaterite (CaCO(3)) precipitated and stabilized in the presence of amino acid molecules in a biomimetic synthesis process.

  20. X-ray evidence for ultra-fast outflows in Seyfert galaxies

    Science.gov (United States)

    Tombesi, Francesco; Braito, Valentina; Reeves, James; Cappi, Massimo; Dadina, Mauro

    2012-07-01

    X-ray evidence for massive, highly ionized, ultra-fast outflows (UFOs) has been recently reported in a number of AGNs through the detection of blue-shifted Fe XXV/XXVI absorption lines. We present the results of a comprehensive spectral analysis of a large sample of 42 local Seyferts observed with XMM-Newton. Similar results are also obtained from a Suzaku analysis of 5 radio galaxies. We find that UFOs are common phenomena, being present in >40% of the sources. Their outflow velocity distribution is in the range ˜0.03--0.3c, with mean value of ˜0.14c. The ionization parameter is very high, in the range logξ˜3--6 erg~s^{-1}~cm, and the associated column densities are also large, in the range ˜10^{22}--10^{24} cm^{-2}. Their location is constrained at ˜0.0003--0.03pc (˜10^2--10^4 r_s) from the central black hole, consistent with what is expected for accretion disk winds/outflows. The mass outflow rates are in the interval ˜0.01--1M_{⊙}~yr^{-1}. The associated mechanical power is also high, in the range ˜10^{43}--10^{45} erg/s, which indicates that UFOs are capable to provide a significant contribution to the AGN cosmological feedback.

  1. Maximum entropy based reconstruction of soft X ray emissivity profiles in W7-AS

    International Nuclear Information System (INIS)

    Ertl, K.; Linden, W. von der; Dose, V.; Weller, A.

    1996-01-01

    The reconstruction of 2-D emissivity profiles from soft X ray tomography measurements constitutes a highly underdetermined and ill-posed inversion problem, because of the restricted viewing access, the number of chords and the increased noise level in most plasma devices. An unbiased and consistent probabilistic approach within the framework of Bayesian inference is provided by the maximum entropy method, which is independent of model assumptions, but allows any prior knowledge available to be incorporated. The formalism is applied to the reconstruction of emissivity profiles in an NBI heated plasma discharge to determine the dependence of the Shafranov shift on β, the reduction of which was a particular objective in designing the advanced W7-AS stellarator. (author). 40 refs, 7 figs

  2. Spectrometer for X-ray emission experiments at FERMI free-electron-laser

    International Nuclear Information System (INIS)

    Poletto, L.; Frassetto, F.; Miotti, P.; Di Cicco, A.; Iesari, F.; Finetti, P.; Grazioli, C.; Kivimäki, A.; Stagira, S.; Coreno, M.

    2014-01-01

    A portable and compact photon spectrometer to be used for photon in-photon out experiments, in particular x-ray emission spectroscopy, is presented. The instrument operates in the 25–800 eV energy range to cover the full emissions of the FEL1 and FEL2 stages of FERMI. The optical design consists of two interchangeable spherical varied-lined-spaced gratings and a CCD detector. Different input sections can be accommodated, with/without an entrance slit and with/without an additional relay mirror, that allow to mount the spectrometer in different end-stations and at variable distances from the target area both at synchrotron and at free-electron-laser beamlines. The characterization on the Gas Phase beamline at ELETTRA Synchrotron (Italy) is presented

  3. Spectral evolution of soft x-ray emission from optically thin, high electron temperature platinum plasmas

    Directory of Open Access Journals (Sweden)

    Hiroyuki Hara

    2017-08-01

    Full Text Available The soft x-ray spectra of heavy element plasmas are frequently dominated by unresolved transition array (UTA emission. We describe the spectral evolution of an intense UTA under optically thin conditions in platinum plasmas. The UTA was observed to have a peak wavelength around 4.6 nm at line-of-sight averaged electron temperatures less than 1.4 keV at electron densities of (2.5–7.5 × 1013 cm−3. The UTA spectral structure was due to emission from 4d–4f transitions in highly charged ions with average charge states of q = 20–40. A numerical simulation successfully reproduced the observed spectral behavior.

  4. Kossel interferences of proton-induced X-ray emission lines in periodic multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Meiyi; Le Guen, Karine; André, Jean-Michel [Sorbonne Universités, UPMC Univ Paris 06, Laboratoire de Chimie Physique-Matière et Rayonnement, 11 rue Pierre et Marie Curie, F-75231 Paris cedex 05 (France); CNRS UMR 7614, Laboratoire de Chimie Physique-Matière et Rayonnement, 11 rue Pierre et Marie Curie, F-75231 Paris cedex 05 (France); Ilakovac, Vita [Sorbonne Universités, UPMC Univ Paris 06, Laboratoire de Chimie Physique-Matière et Rayonnement, 11 rue Pierre et Marie Curie, F-75231 Paris cedex 05 (France); CNRS UMR 7614, Laboratoire de Chimie Physique-Matière et Rayonnement, 11 rue Pierre et Marie Curie, F-75231 Paris cedex 05 (France); Université de Cergy-Pontoise, F-95031 Cergy-Pontoise (France); Vickridge, Ian [Sorbonne Universités, UPMC Univ Paris 06, Institut des NanoSciences de Paris, 4 place Jussieu, boîte courrier 840, F-75252 Paris cedex 05 (France); CNRS UMR 7588, Institut des NanoSciences de Paris, 4 place Jussieu, boîte courrier 840, F-75252 Paris cedex 05 (France); Schmaus, Didier [Sorbonne Universités, UPMC Univ Paris 06, Institut des NanoSciences de Paris, 4 place Jussieu, boîte courrier 840, F-75252 Paris cedex 05 (France); CNRS UMR 7588, Institut des NanoSciences de Paris, 4 place Jussieu, boîte courrier 840, F-75252 Paris cedex 05 (France); Université Paris Diderot-P7, F-75205 Paris cedex 13 (France); and others

    2016-11-01

    The Kossel interferences generated by characteristic X-ray lines produced inside a periodic multilayer have been observed upon proton irradiation, by submitting a Cr/B{sub 4}C/Sc multilayer stack to 2 MeV protons and observing the intensity of the Sc and Cr Kα characteristic emissions as a function of the detection angle. When this angle is close to the Bragg angle corresponding to the emission wavelength and period of the multilayer, an oscillation of the measured intensity is detected. The results are in good agreement with a model based on the reciprocity theorem. The combination of the Kossel measurements and their simulation, will be a useful tool to obtain a good description of the multilayer stack and thus to study nanometer-thick layers and their interfaces.

  5. Particle induced X-ray emission and complementary nuclear methods for trace element determination; Plenary lecture

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, S A.E. [Lund Univ. (Sweden). Dept. of Nuclear Physics

    1992-03-01

    In this review the state-of-the-art of particle induced X-ray emission (PIXE) methods for the determination of trace elements is described. The developmental work has mostly been carried out in nuclear physics laboratories, where accelerators are available, but now the increased interest has led to the establishment of other dedicated PIXE facilities. The reason for this interest is the versatility, high sensitivity and multi-element capability of PIXE analysis. A further very important advantage is that PIXE can be combined with the microbeam technique, which makes elemental mapping with a spatial resolution of about 1 {mu}m possible. As a technique, PIXE can also be combined with other nuclear reactions such as elastic scattering and particle-induced gamma emission, so that light elements can be determined. The usefulness of PIXE is illustrated by a number of typical applications in biology, medicine, geology, air pollution research, archaeology and the arts. (author).

  6. A theoretical model evaluating the angular distribution of luminescence emission in X-ray scintillating screens

    International Nuclear Information System (INIS)

    Kandarakis, I.; Cavouras, D.; Nikolopoulos, D.; Episkopakis, A.; Kalivas, N.; Liaparinos, P.; Valais, I.; Kagadis, G.; Kourkoutas, K.; Sianoudis, I.; Dimitropoulos, N.; Nomicos, C.; Panayiotakis, G.

    2006-01-01

    The aim of this study was to examine the angular distribution of the light emitted from radiation-excited scintillators in medical imaging detectors. This distribution diverges from Lambert's cosine law and affects the light emission efficiency of scintillators, hence it also affects the dose burden to the patient. In the present study, the angular distribution was theoretically modeled and was used to fit experimental data on various scintillator materials. Results of calculations revealed that the angular distribution is more directional than that predicted by Lambert's law. Divergence from this law is more pronounced for high values of light attenuation coefficient and thick scintillator layers (screens). This type of divergence reduces light emission efficiency and hence it increases the incident X-ray flux required for a given level of image brightness

  7. High-resolution X-ray emission spectroscopy with transition-edge sensors: present performance and future potential

    Energy Technology Data Exchange (ETDEWEB)

    Uhlig, J.; Doriese, W. B.; Fowler, J. W.; Swetz, D. S.; Jaye, C.; Fischer, D. A.; Reintsema, C. D.; Bennett, D. A.; Vale, L. R.; Mandal, U.; O' Neil, G. C.; Miaja-Avila, L.; Joe, Y. I.; El Nahhas, A.; Fullagar, W.; Parnefjord Gustafsson, F.; Sundström, V.; Kurunthu, D.; Hilton, G. C.; Schmidt, D. R.; Ullom, J. N.

    2015-04-21

    X-ray emission spectroscopy (XES) is a powerful element-selective tool to analyze the oxidation states of atoms in complex compounds, determine their electronic configuration, and identify unknown compounds in challenging environments. Until now the low efficiency of wavelength-dispersive X-ray spectrometer technology has limited the use of XES, especially in combination with weaker laboratory X-ray sources. More efficient energy-dispersive detectors have either insufficient energy resolution because of the statistical limits described by Fano or too low counting rates to be of practical use. This paper updates an approach to high-resolution X-ray emission spectroscopy that uses a microcalorimeter detector array of superconducting transition-edge sensors (TESs). TES arrays are discussed and compared with conventional methods, and shown under which circumstances they are superior. It is also shown that a TES array can be integrated into a table-top time-resolved X-ray source and a soft X-ray synchrotron beamline to perform emission spectroscopy with good chemical sensitivity over a very wide range of energies.

  8. The Origin of the Extra-nuclear X-ray Emission in the Seyfert Galaxy NGC 2992

    Science.gov (United States)

    Colbert, E. J. M.; Strickland, D. K.; Veilleux, S.; Weaver, K. A.

    2004-12-01

    We present an analysis of a Chandra ACIS observation of the edge-on Seyfert galaxy NGC 2992. We find extended X-ray emission with Lx(total) in excess of 10**40 erg/s. The brightest nebula is positioned a few 100 pc from the X-ray core, and is spatially coincident with optical line and radio emission. This emission nebula may be energized by the AGN, as opposed to a nuclear starburst. The expected kpc-scale X-ray emission due to a starburst-driven wind is larger than a few 10**39 erg/s, and we present large-scale X-ray emission that may be associated with such an outflow. The extra-nuclear emission has a very soft spectrum. Chandra and XMM spectra of the total nuclear region show a very prominent ``soft excess'' below 2-3 keV. We shall discuss the spectral properties of this soft excess, and will compare with the results from the spatial analysis, and with AGN and starburst models for extranuclear X-ray nebulae.

  9. Soft x-ray emission from postpulse expanding laser-produced plasmas

    International Nuclear Information System (INIS)

    Weaver, J.L.; Feldman, U.; Mostovych, A.N.; Seely, J.F.; Colombant, D.; Holland, G.

    2003-01-01

    A diagnostic spectrometer has been developed at the Naval Research Laboratory to measure the time resolved absolute intensity of radiation emitted from targets irradiated by the Nike laser. The spectrometer consists of a dispersive transmission grating of 2500 lines/mm or 5000 lines/mm and a detection system consisting of an absolutely calibrated Si photodiode array and a charge coupled device camera. In this article, this spectrometer was used to study the spatial distribution of soft x-ray radiation from low Z elements (primarily carbon) that lasted tens of nanoseconds after the main laser illumination was over. We recorded soft x-ray emission as a function of the target material and target orientation with respect to the incoming laser beam and the spectrometer line of sight. While a number of spectral features have been identified in the data, the instrument's combined temporal and spatial resolution allowed observation of the plasma expansion from CH targets for up to ∼25 ns after the cessation of the main laser pulse. The inferred plasma expansion velocities are slightly higher than those previously reported

  10. Resolving the hard X-ray emission of GX 5-1 with INTEGRAL

    DEFF Research Database (Denmark)

    Paizis, A.; Ebisawa, K.; Tikkanen, T.

    2005-01-01

    We present the study of one year of INTEGRAL data on the neutron star low mass X-ray binary GX 5-1. Thanks to the excellent angular resolution and sensitivity of INTEGRAL, we are able to obtain a high quality spectrum of GX 5-1 from similar to 5keV to similar to 100 keV, for the first time without...... contamination from the nearby black hole candidate GRS 1758-258 above 20 keV. During our observations, GX 5-1 was mostly found in the horizontal and normal branch of its hardness intensity diagram. A clear hard X-ray emission is observed above similar to 30 keV which exceeds the exponential cut-off spectrum...... expected from lower energies. This spectral flattening may have the same origin of the hard components observed in other Z sources as it shares the property of being characteristic to the horizontal branch. The hard excess is explained by introducing Compton up-scattering of soft photons from the neutron...

  11. X-Ray, EUV, UV and Optical Emissivities of Astrophysical Plasmas

    Science.gov (United States)

    Raymond, John C.; West, Donald (Technical Monitor)

    2000-01-01

    This grant primarily covered the development of the thermal X-ray emission model code called APEC, which is meant to replace the Raymond and Smith (1977) code. The new code contains far more spectral lines and a great deal of updated atomic data. The code is now available (http://hea-www.harvard.edu/APEC), though new atomic data is still being added, particularly at longer wavelengths. While initial development of the code was funded by this grant, current work is carried on by N. Brickhouse, R. Smith and D. Liedahl under separate funding. Over the last five years, the grant has provided salary support for N. Brickhouse, R. Smith, a summer student (L. McAllister), an SAO predoctoral fellow (A. Vasquez), and visits by T. Kallman, D. Liedahl, P. Ghavamian, J.M. Laming, J. Li, P. Okeke, and M. Martos. In addition to the code development, the grant supported investigations into X-ray and UV spectral diagnostics as applied to shock waves in the ISM, accreting black holes and white dwarfs, and stellar coronae. Many of these efforts are continuing. Closely related work on the shock waves and coronal mass ejections in the solar corona has grown out of the efforts supported by the grant.

  12. Proton-induced X-ray emission analysis of marine particulates

    International Nuclear Information System (INIS)

    Burnett, W.C.; Mitchum, G.T.

    1981-01-01

    We report a methodology used to analyze suspended marine particulates by particle induced X-ray emission (PIXE). Water samples from an estuary in Brazil were filtered soon after collection onto pre-weighed Nuclepore filters, washed with deionized water, dried to constant weight and analyzed as thin targets. Because of the relatively high mass loadings (0.1-1.0 mg/cm 2 ) on the filters, proton bombardment times of a few minutes were adequate for maintaining good counting statistics. Precision and accuary were determined by replicate analysis and intercomparison to geochemical standards. Suspensions of standards in deionized water were filtered dried, weighed and analyzed in a similar fashion as our samples of marine particulates. Net X-ray intensities were related to mass by calibration against pure elemental standards. Initial experiments showed systematically low concentrations for all elements determined by PIXE relative to known values. Further experiments verified that this systematic errors was due to an uneven distribution of mass on the surface of the filters. Improvements in the filtration technique have eliminated the topographic effect on our samples and the PIXE resultes were substantially improved. Variations in matrix and particle size of the samples analyzed did not cause any measureable analytical effect. PIXE thus seems well suited for providing rapid, multi-element data on samples of marine particulates if suitable precautions are made during the sample preparation process. (orig.)

  13. Pulse-periodic generation of supershort avalanche electron beams and X-ray emission

    Science.gov (United States)

    Baksht, E. Kh.; Burachenko, A. G.; Erofeev, M. V.; Tarasenko, V. F.

    2014-05-01

    Pulse-periodic generation of supershort avalanche electron beams (SAEBs) and X-ray emission in nitrogen, as well as the transition from a single-pulse mode to a pulse-periodic mode with a high repetition frequency, was studied experimentally. It is shown that, in the pulse-periodic mode, the full width at halfmaximum of the SAEB is larger and the decrease rate of the gap voltage is lower than those in the single-pulse mode. It is found that, when the front duration of the voltage pulse at a nitrogen pressure of 90 Torr decreases from 2.5 to 0.3 ns, the X-ray exposure dose in the pulse-periodic mode increases by more than one order of magnitude and the number of SAEB electrons also increases. It is shown that, in the pulse-periodic mode of a diffuse discharge, gas heating in the discharge gap results in a severalfold increase in the SAEB amplitude (the number of electrons in the beam). At a generator voltage of 25 kV, nitrogen pressure of 90 Torr, and pulse repetition frequency of 3.5 kHz, a runaway electron beam was detected behind the anode foil.

  14. Accretion dynamics and polarized x-ray emission of magnetized neutron stars

    International Nuclear Information System (INIS)

    Arons, J.

    1991-01-01

    The basic ideas of accretion onto magnetized neutron stars are outlined. These are applied to a simple model of the structure of the plasma mound sitting at the magnetic poles of such as star, in which upward diffusion of photons is balanced by their downward advection. This steady flow model of the plasma's dynamical state is used to compute the emission of polarized X-rays from the optically thick, birefringent medium. The linear polarization of the continuum radiation emerging from the quasi-static mound is found to be as much as 40% at some rotation phases, but is insensitive to the geometry of the accretion flow. The role of the accretion shock, whose detailed polarimetric and spectral characteristics have yet to be calculated, is emphasized as the final determinant of the properties of the emerging X-rays. Some results describing the fully time dependent dynamics of the flow are also presented. In particular, steady flow onto a neutron star is shown to exhibit formation of ''photon bubbles,'' regions of greatly reduced plasma density filled with radiation which form and rise on millisecond time scales. The possible role of these complex structures in the flow for the formation of the emergent spectrum is briefly outlined

  15. Soft x-ray emission from postpulse expanding laser-produced plasmas

    Science.gov (United States)

    Weaver, J. L.; Feldman, U.; Mostovych, A. N.; Seely, J. F.; Colombant, D.; Holland, G.

    2003-12-01

    A diagnostic spectrometer has been developed at the Naval Research Laboratory to measure the time resolved absolute intensity of radiation emitted from targets irradiated by the Nike laser. The spectrometer consists of a dispersive transmission grating of 2500 lines/mm or 5000 lines/mm and a detection system consisting of an absolutely calibrated Si photodiode array and a charge coupled device camera. In this article, this spectrometer was used to study the spatial distribution of soft x-ray radiation from low Z elements (primarily carbon) that lasted tens of nanoseconds after the main laser illumination was over. We recorded soft x-ray emission as a function of the target material and target orientation with respect to the incoming laser beam and the spectrometer line of sight. While a number of spectral features have been identified in the data, the instrument's combined temporal and spatial resolution allowed observation of the plasma expansion from CH targets for up to ˜25 ns after the cessation of the main laser pulse. The inferred plasma expansion velocities are slightly higher than those previously reported.

  16. Applications of X-ray emission to elemental analysis of foods

    International Nuclear Information System (INIS)

    Flocchini, R.G.; Lagunas-Solar, M.C.; Perley, B.P.

    1996-01-01

    Trace element analysis via X-Ray Fluorescence (XRF) and Proton-Induced X-Ray Emission (PIXE) techniques were applied to several samples of fresh and processed foods. Thin samples of fresh fruits and vegetables, processed dry foods, and spices were included in these analyses. The results indicate that XRF and/or PIXE analysis is applicable to these types of samples but require special and simple modifications in sample preparation techniques, and the inclusion of new matrix type corrections for data analysis. However, the non-destructive nature, reproducibility, efficiency and high sensitivity that characterize these multi-element analytical procedures can provide new potential methods for detecting trace elements in foods and in many agricultural commodities. Toxic metals such as Hg, Pb, and As were detected in some foods. In addition, other essential or neutral trace elements such as Na, K, Mg, Ca, Cu, Cr, V, Zn, Mo, Fe, Mn, Ni, Se, Cl, S, and P were also detected. These and other elements can be analyzed rapidly and with high sensitivity for applications in process control and for certification of food quality. Developing these techniques and procedures specifically for food and for various agricultural products may provide new analytical options and help mitigate the expected impact of forthcoming regulations intended to establish limits and tolerance levels for micro toxicants and other essential nutrients in foods and agricultural products. (author)

  17. X-RAY EMISSION FROM YOUNG STARS IN THE MASSIVE STAR-FORMING REGION IRAS 20126+4104

    International Nuclear Information System (INIS)

    Anderson, C. N.; Hofner, P.; Creech-Eakman, M.; Shepherd, D.

    2011-01-01

    We present a 40 ks Chandra observation of the IRAS 20126+4104 core region. In the inner 6'' two X-ray sources were detected, which are coincident with the radio jet source I20S and the variable radio source I20Var. No X-ray emission was detected from the nearby massive protostar I20N. The spectra of both detected sources are hard and highly absorbed, with no emission below 3 keV. For I20S, the measured 0.5-8 keV count rate was 4.3 counts ks -1 . The X-ray spectrum was fitted with an absorbed 1T APEC model with an energy of kT =10 keV and an absorbing column of N H = 1.2 x 10 23 cm -2 . An unabsorbed X-ray luminosity of about 1.4 x 10 32 erg s -1 was estimated. The spectrum shows broad line emission between 6.4 and 6.7 keV, indicative of emission from both neutral and highly ionized iron. The X-ray light curve indicates that I20S is marginally variable; however, no flare emission was observed. The variable radio source I20Var was detected with a count rate of 0.9 counts ks -1 but there was no evidence of X-ray variability. The best-fit spectral model is a 1T APEC model with an absorbing hydrogen column of N H = 1.1 x 10 23 cm -2 and a plasma energy of kT = 6.0 keV. The unabsorbed X-ray luminosity is about 3 x 10 31 erg s -1 .

  18. Ultrasonic acoustic levitation for fast frame rate X-ray protein crystallography at room temperature

    OpenAIRE

    Soichiro Tsujino; Takashi Tomizaki

    2016-01-01

    Increasing the data acquisition rate of X-ray diffraction images for macromolecular crystals at room temperature at synchrotrons has the potential to significantly accelerate both structural analysis of biomolecules and structure-based drug developments. Using lysozyme model crystals, we demonstrated the rapid acquisition of X-ray diffraction datasets by combining a high frame rate pixel array detector with ultrasonic acoustic levitation of protein crystals in liquid droplets. The rapid spinn...

  19. Masked-backlighter technique used to simultaneously image x-ray absorption and x-ray emission from an inertial confinement fusion plasma

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, F. J., E-mail: fredm@lle.rochester.edu; Radha, P. B. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States)

    2014-11-15

    A method to simultaneously image both the absorption and the self-emission of an imploding inertial confinement fusion plasma has been demonstrated on the OMEGA Laser System. The technique involves the use of a high-Z backlighter, half of which is covered with a low-Z material, and a high-speed x-ray framing camera aligned to capture images backlit by this masked backlighter. Two strips of the four-strip framing camera record images backlit by the high-Z portion of the backlighter, while the other two strips record images aligned with the low-Z portion of the backlighter. The emission from the low-Z material is effectively eliminated by a high-Z filter positioned in front of the framing camera, limiting the detected backlighter emission to that of the principal emission line of the high-Z material. As a result, half of the images are of self-emission from the plasma and the other half are of self-emission plus the backlighter. The advantage of this technique is that the self-emission simultaneous with backlighter absorption is independently measured from a nearby direction. The absorption occurs only in the high-Z backlit frames and is either spatially separated from the emission or the self-emission is suppressed by filtering, or by using a backlighter much brighter than the self-emission, or by subtraction. The masked-backlighter technique has been used on the OMEGA Laser System to simultaneously measure the emission profiles and the absorption profiles of polar-driven implosions.

  20. Masked-backlighter technique used to simultaneously image x-ray absorption and x-ray emission from an inertial confinement fusion plasma.

    Science.gov (United States)

    Marshall, F J; Radha, P B

    2014-11-01

    A method to simultaneously image both the absorption and the self-emission of an imploding inertial confinement fusion plasma has been demonstrated on the OMEGA Laser System. The technique involves the use of a high-Z backlighter, half of which is covered with a low-Z material, and a high-speed x-ray framing camera aligned to capture images backlit by this masked backlighter. Two strips of the four-strip framing camera record images backlit by the high-Z portion of the backlighter, while the other two strips record images aligned with the low-Z portion of the backlighter. The emission from the low-Z material is effectively eliminated by a high-Z filter positioned in front of the framing camera, limiting the detected backlighter emission to that of the principal emission line of the high-Z material. As a result, half of the images are of self-emission from the plasma and the other half are of self-emission plus the backlighter. The advantage of this technique is that the self-emission simultaneous with backlighter absorption is independently measured from a nearby direction. The absorption occurs only in the high-Z backlit frames and is either spatially separated from the emission or the self-emission is suppressed by filtering, or by using a backlighter much brighter than the self-emission, or by subtraction. The masked-backlighter technique has been used on the OMEGA Laser System to simultaneously measure the emission profiles and the absorption profiles of polar-driven implosions.

  1. X-RAY AND MULTIWAVELENGTH INSIGHTS INTO THE NATURE OF WEAK EMISSION-LINE QUASARS AT LOW REDSHIFT

    Energy Technology Data Exchange (ETDEWEB)

    Wu Jianfeng; Brandt, W. N.; Schneider, Donald P. [Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Lab, University Park, PA 16802 (United States); Anderson, Scott F. [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); Diamond-Stanic, Aleksandar M. [Center for Astrophysics and Space Sciences, University of California, San Diego, La Jolla, CA 92903 (United States); Hall, Patrick B. [Department of Physics and Astronomy, York University, 4700 Keele Street, Toronto, ON M3J 1P3 (Canada); Plotkin, Richard M. [Astronomical Institute ' Anton Pannekoek' , University of Amsterdam, Science Park 904, 1098 XH Amsterdam (Netherlands); Shemmer, Ohad, E-mail: jfwu@astro.psu.edu [Department of Physics, University of North Texas, Denton, TX 76203 (United States)

    2012-03-01

    We report on the X-ray and multiwavelength properties of 11 radio-quiet quasars with weak or no emission lines identified by the Sloan Digital Sky Survey (SDSS) with redshift z = 0.4-2.5. Our sample was selected from the Plotkin et al. catalog of radio-quiet, weak-featured active galactic nuclei (AGNs). The distribution of relative X-ray brightness for our low-redshift weak-line quasar (WLQ) candidates is significantly different from that of typical radio-quiet quasars, having an excess of X-ray weak sources, but it is consistent with that of high-redshift WLQs. Over half of the low-redshift WLQ candidates are X-ray weak by a factor of {approx}> 5, compared to a typical SDSS quasar with similar UV/optical luminosity. These X-ray weak sources generally show similar UV emission-line properties to those of the X-ray weak quasar PHL 1811 (weak and blueshifted high-ionization lines, weak semiforbidden lines, and strong UV Fe emission); they may belong to the notable class of PHL 1811 analogs. The average X-ray spectrum of these sources is somewhat harder than that of typical radio-quiet quasars. Several other low-redshift WLQ candidates have normal ratios of X-ray-to-optical/UV flux, and their average X-ray spectral properties are also similar to those of typical radio-quiet quasars. The X-ray weak and X-ray normal WLQ candidates may belong to the same subset of quasars having high-ionization 'shielding gas' covering most of the wind-dominated broad emission-line region, but be viewed at different inclinations. The mid-infrared-to-X-ray spectral energy distributions (SEDs) of these sources are generally consistent with those of typical SDSS quasars, showing that they are not likely to be BL Lac objects with relativistically boosted continua and diluted emission lines. The mid-infrared-to-UV SEDs of most radio-quiet weak-featured AGNs without sensitive X-ray coverage (34 objects) are also consistent with those of typical SDSS quasars. However, one source in our

  2. X-RAY AND MULTIWAVELENGTH INSIGHTS INTO THE NATURE OF WEAK EMISSION-LINE QUASARS AT LOW REDSHIFT

    International Nuclear Information System (INIS)

    Wu Jianfeng; Brandt, W. N.; Schneider, Donald P.; Anderson, Scott F.; Diamond-Stanic, Aleksandar M.; Hall, Patrick B.; Plotkin, Richard M.; Shemmer, Ohad

    2012-01-01

    We report on the X-ray and multiwavelength properties of 11 radio-quiet quasars with weak or no emission lines identified by the Sloan Digital Sky Survey (SDSS) with redshift z = 0.4-2.5. Our sample was selected from the Plotkin et al. catalog of radio-quiet, weak-featured active galactic nuclei (AGNs). The distribution of relative X-ray brightness for our low-redshift weak-line quasar (WLQ) candidates is significantly different from that of typical radio-quiet quasars, having an excess of X-ray weak sources, but it is consistent with that of high-redshift WLQs. Over half of the low-redshift WLQ candidates are X-ray weak by a factor of ∼> 5, compared to a typical SDSS quasar with similar UV/optical luminosity. These X-ray weak sources generally show similar UV emission-line properties to those of the X-ray weak quasar PHL 1811 (weak and blueshifted high-ionization lines, weak semiforbidden lines, and strong UV Fe emission); they may belong to the notable class of PHL 1811 analogs. The average X-ray spectrum of these sources is somewhat harder than that of typical radio-quiet quasars. Several other low-redshift WLQ candidates have normal ratios of X-ray-to-optical/UV flux, and their average X-ray spectral properties are also similar to those of typical radio-quiet quasars. The X-ray weak and X-ray normal WLQ candidates may belong to the same subset of quasars having high-ionization 'shielding gas' covering most of the wind-dominated broad emission-line region, but be viewed at different inclinations. The mid-infrared-to-X-ray spectral energy distributions (SEDs) of these sources are generally consistent with those of typical SDSS quasars, showing that they are not likely to be BL Lac objects with relativistically boosted continua and diluted emission lines. The mid-infrared-to-UV SEDs of most radio-quiet weak-featured AGNs without sensitive X-ray coverage (34 objects) are also consistent with those of typical SDSS quasars. However, one source in our X-ray

  3. Characterization of offset printing ink tagged with rare-earth taggants by X-ray emission techniques

    International Nuclear Information System (INIS)

    Joseph, D.; Saxena, A.; Choudhury, R.K.; Maind, S.D.

    2007-01-01

    Proton Induced X-ray Emission (PIXE) and Energy Dispersive X-ray Fluorescence (EDXRF) techniques have been used for elemental characterization of offset printing ink tagged with rare-earth taggants. The offset printing ink was tagged with rare-earth (La, Pr, Nd, Sm, Eu and Gd) thenoyltrifluoroacetonate chelates at about 1000-ppm level for each element separately. Small aliquots (approximately 20 mg) of tagged inks were coated on paper supports in the form of small circles having diameter 10-15 mm each and then analyzed. In the case of PIXE, a proton beam of energy 4 MeV and in the case of EDXRF a radioisotope source of 241 Am (100 mCi) was used to excite the samples. The PIXE analysis showed well-resolved rare-earth L X-rays and EDXRF analysis showed the K X-rays of rare earths. Satisfactory results to identify and quantify the taggants were achieved. (author)

  4. Elemental and mineralogical study of earth-based pigments using particle induced X-ray emission and X-ray diffraction

    International Nuclear Information System (INIS)

    Nel, P.; Lynch, P.A.; Laird, J.S.; Casey, H.M.; Goodall, L.J.; Ryan, C.G.; Sloggett, R.J.

    2010-01-01

    Artwork and precious artefacts demand non-destructive analytical methodologies for art authentication, attribution and provenance assessment. However, structural and chemical characterisation represents a challenging problem with existing analytical techniques. A recent authentication case based on an Australian Aboriginal artwork, indicate there is substantial benefit in the ability of particle induced X-ray emission (PIXE), coupled with dynamic analysis (DA) to characterise pigments through trace element analysis. However, this information alone is insufficient for characterising the mineralogical residence of trace elements. For this reason a combined methodology based on PIXE and X-ray diffraction (XRD) has been performed to explore the benefits of a more comprehensive data set. Many Aboriginal paintings and artefacts are predominantly earth pigment based. This makes these cultural heritage materials an ideal case study for testing the above combined methodological approach on earth-based pigments. Samples of synthetic and naturally occurring earth-based pigments were obtained from a range of sources, which include Indigenous communities within Australia's Kimberley region. PIXE analyses using a 3 MeV focussed proton beam at the CSIRO nuclear microprobe, as well as laboratory-based XRD was carried out on the above samples. Elemental signature spectra as well as mineralogical data were used to assess issues regarding synthetic and naturally occurring earth pigments with the ultimate aim of establishing provenance.

  5. Observation of soft X-ray spectra from a Seyfert 1 and a narrow emission-line galaxy

    International Nuclear Information System (INIS)

    Singh, K.P.; Garmire, G.P.; Nousek, J.

    1985-01-01

    The 0.2-40 keV X-ray spectra of the Seyfert 1 galaxy Mrk 509 and the narrow emission-line galaxy NGC 2992 are analyzed. The results suggest the presence of a steep soft X-ray component in Mrk 509 in addition to the well-known Gamma = 1.7 component found in other active galactic nuclei in the 2-40 keV energy range. The soft X-ray component is interpreted as due to thermal emission from a hot gas, probably associated with the highly ionized gas observed to be outflowing from the galaxy. The X-ray spectrum of NGC 2992 does not show any steepening in the soft X-ray band and is consistent with a single power law (Gamma = 1.78) with very low absorbing column density of 4 x 10 to the 21st/sq cm. A model with partial covering of the nuclear X-ray source is preferred, however, to a simple model with a single power law and absorption. 34 references

  6. Discovery of Spatial and Spectral Structure in the X-Ray Emission from the Crab Nebula

    Science.gov (United States)

    Weisskopf, Martin C.; Hester, J. Jeff; Tennant, Allyn F.; Elsner, Ronald F.; Schulz, Norbert S.; Marshall, Herman L.; Karovska, Margarita; Nichols, Joy S.; Swartz, Douglas A.; Kolodziejczak, Jeffery J.

    2000-01-01

    The Chandra X-Ray Observatory observed the Crab Nebula and pulsar during orbital calibration. Zeroth-order images with the High-Energy Transmission Grating (HETG) readout by the Advanced Charge Coupled Devices (CCD) Imaging Spectrometer spectroscopy array (ACIS-S) show a striking richness of X-ray structure at a resolution comparable to that of the best ground-based visible-light observations. The HETG-ACIS-S images reveal, for the first time, an X-ray inner ring within the X-ray torus, the suggestion of a hollow-tube structure for the torus, and X-ray knots along the inner ring and (perhaps) along the inward extension of the X-ray jet. Although complicated by instrumental effects and the brightness of the Crab Nebula, the spectrometric analysis shows systematic variations of the X-ray spectrum throughout the nebula.

  7. Discovery of Spatial and Spectral Structure in the X-Ray Emission from the Crab Nebula.

    Science.gov (United States)

    Weisskopf; Hester; Tennant; Elsner; Schulz; Marshall; Karovska; Nichols; Swartz; Kolodziejczak; O'Dell

    2000-06-20

    The Chandra X-Ray Observatory observed the Crab Nebula and pulsar during orbital calibration. Zeroth-order images with the High-Energy Transmission Grating (HETG) readout by the Advanced CCD Imaging Spectrometer spectroscopy array (ACIS-S) show a striking richness of X-ray structure at a resolution comparable to that of the best ground-based visible-light observations. The HETG-ACIS-S images reveal, for the first time, an X-ray inner ring within the X-ray torus, the suggestion of a hollow-tube structure for the torus, and X-ray knots along the inner ring and (perhaps) along the inward extension of the X-ray jet. Although complicated by instrumental effects and the brightness of the Crab Nebula, the spectrometric analysis shows systematic variations of the X-ray spectrum throughout the nebula.

  8. Correlated X-ray/UV/optical emission and short-term variability in a Seyfert 1 galaxy NGC 4593

    Science.gov (United States)

    Pal, Main; Naik, Sachindra

    2018-03-01

    We present a detailed multifrequency analysis of an intense monitoring programme of Seyfert 1 galaxy NGC 4593 over a duration of nearly for a month with Swift observatory. We used 185 pointings to study the variability in six ultraviolet/optical and two soft (0.3-1.5 keV) and hard X-ray (1.5-10 keV) bands. The amplitude of the observed variability is found to decrease from high energy to low energy (X-ray to optical) bands. Count-count plots of ultraviolet/optical bands with hard X-rays clearly suggest the presence of a mixture of two major components: (i) highly variable component such as hard X-ray emission, and (ii) slowly varying disc-like component. The variations observed in the ultraviolet/optical emission are strongly correlated with the hard X-ray band. Cross-correlation analysis provides the lags for the longer wavelengths compared to the hard X-rays. Such lags clearly suggest that the changes in the ultraviolet/optical bands follow the variations in the hard X-ray band. This implies that the observed variation in longer wavelengths is due to X-ray reprocessing. Though, the measured lag spectrum (lag versus wavelength) is well described by λ4/3 as expected from the standard disc model, the observed lags are found to be longer than the predicted values from standard disc model. This implies that the actual size of the disc of NGC 4593 is larger than the estimated size of standard thin disc as reported in active galactic nuclei such as NGC 5548 and Fairall 9.

  9. Steep Hard-X-ray Spectra Indicate Extremely High Accretion Rates in Weak Emission-Line Quasars

    Science.gov (United States)

    Marlar, Andrea; Shemmer, Ohad; Anderson, Scott F.; Brandt, W. Niel; Diamond-Stanic, Aleksandar M.; Fan, Xiaohui; Luo, Bin; Plotkin, Richard; Richards, Gordon T.; Schneider, Donald P.; Wu, Jianfeng

    2018-06-01

    We present XMM-Newton imaging spectroscopy of ten weak emission-line quasars (WLQs) at 0.928 ≤ z ≤ 3.767, six of which are radio quiet and four which are radio intermediate. The new X-ray data enabled us to measure the hard-X-ray power-law photon index (Γ) in each source with relatively high accuracy. These measurements allowed us to confirm previous reports that WLQs have steeper X-ray spectra, therefore indicating higher accretion rates with respect to "typical" quasars. A comparison between the Γ values of our radio-quiet WLQs and those of a carefully-selected, uniform sample of 84 quasars shows that the first are significantly higher, at the ≥ 3σ level. Collectively, the four radio-intermediate WLQs have lower Γ values with respect to the six radio-quiet WLQs, as may be expected if the spectra of the first group are contaminated by X-ray emission from a jet. These results suggest that, in the absence of significant jet emission along our line of sight, WLQs constitute the extreme high end of the accretion rate distribution in quasars. We detect soft excess emission in our lowest-redshift radio-quiet WLQ, in agreement with previous findings suggesting that the prominence of this feature is associated with a high accretion rate. We have not detected signatures of Compton reflection, Fe Kα lines, or strong variability between two X-ray epochs in any of our WLQs.

  10. Intense Non-Linear Soft X-Ray Emission from a Hydride Target during Pulsed D Bombardment

    Science.gov (United States)

    Miley, George H.; Yang, Yang; Lipson, Andrei; Haque, Munima; Percel, Ian; Romer, Michael

    Radiation emission from low-energy nuclear radiation (LENR) electrodes (both charged-particle and X-rays) represents an important feature of LENR in general. Here, calibration, measurement techniques, and soft X-ray emission results from deuterium bombardment of a Pd target (cathode) placed in a pulsed deuterium glow discharge (PGD) are described. An X-ray intensity of 13.4 mW/cm2 and a dose of 3.3 μJ/cm2 were calculated over a 0.5 ms pulse time from AXUV photodiode radiation detector measurements. A most striking feature is that X-ray energies >600 V are observed with a discharge voltage only about half of that value. To further investigate this phenomenon, emission during room temperature D-desorption from electrolytically loaded Pd:Dx cathodes was also studied. The X-ray emission energy observed was quite similar to the PGD case. However, the intensity in this case was almost 13 orders of magnitude lower due to the much lower deuterium fluxes involved.

  11. Intense non-linear soft X-ray emission from a hydride target during pulsed D bombardment

    International Nuclear Information System (INIS)

    Miley, George H.; Yang, Yang; Lipson, Andrei; Haque, Munima; Percel, Ian; Romer, Michael

    2006-01-01

    Radiation emission from low-energy nuclear radiation (LENR) electrodes (both charged-particle and X-rays) represents an important feature of LENR in general. Here, calibration, measurement techniques, and soft X-ray emission results from deuterium bombardment of a Pd target (cathode) placed in a pulsed deuterium glow discharge (PGD) are described. An X-ray intensity of 13.4 mW/cm 2 and a dose of 3.3 μJ/cm 2 were calculated over a 0.5 ms pulse time from AXUV photodiode radiation detector measurements. A most striking feature is that X-ray energies >600 V are observed with a discharge voltage only about half of that value. To further investigate this phenomenon, emission during room temperature D-desorption from electrolytically loaded Pd:Dx cathodes was also studied. The X-ray emission energy observed was quite similar to the PGD case. However, the intensity in this case was almost 13 orders of magnitude lower due to the much lower deuterium fluxes involved. (author)

  12. C IV EMISSION AND THE ULTRAVIOLET THROUGH X-RAY SPECTRAL ENERGY DISTRIBUTION OF RADIO-QUIET QUASARS

    International Nuclear Information System (INIS)

    Kruczek, Nicholas E.; Richards, Gordon T.; Deo, Rajesh P.; Krawczyk, Coleman M.; Gallagher, S. C.; Hall, Patrick B.; Hewett, Paul C.; Leighly, Karen M.; Proga, Daniel

    2011-01-01

    In the rest-frame ultraviolet (UV), two of the parameters that best characterize the range of emission-line properties in quasar broad emission-line regions are the equivalent width and the blueshift of the C IV λ1549 line relative to the quasar rest frame. We explore the connection between these emission-line properties and the UV through X-ray spectral energy distribution (SED) for radio-quiet (RQ) quasars. Our sample consists of a heterogeneous compilation of 406 quasars from the Sloan Digital Sky Survey (at z > 1.54) and Palomar-Green survey (at z < 0.4) that have well-measured C IV emission-line and X-ray properties (including 164 objects with measured Γ). We find that RQ quasars with both strong C IV emission and small C IV blueshifts can be classified as 'hard-spectrum' sources that are (relatively) strong in the X-ray as compared to the UV. On the other hand, RQ quasars with both weak C IV emission and large C IV blueshifts are instead 'soft-spectrum' sources that are (relatively) weak in the X-ray as compared to the UV. This work helps to further bridge optical/soft X-ray 'eigenvector 1' relationships to the UV and hard X-ray. Based on these findings, we argue that future work should consider systematic errors in bolometric corrections (and thus accretion rates) that are derived from a single mean SED. Detailed analysis of the C IV emission line may allow for SED-dependent corrections to these quantities.

  13. Trace element determination in tomato puree using particle induced X-ray emission and Rutherford backscattering

    International Nuclear Information System (INIS)

    Romero-Davila, E.; Miranda, J.

    2004-01-01

    Particle induced X-ray emission (PIXE) and Rutherford backscattering spectrometry (RBS) were used to determine the concentrations of trace elements in samples of 12 tomato puree brands sold in the Mexican market. While RBS offered information about the main elements present in the matrix, PIXE gave results on trace elements. As a whole, data for 17 elements (C, N, O, Na, Mg, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, and Zn) were obtained. To evaluate the results, a comparison with brands from USA, Japan, Colombia, and Chile was carried out, using tomato purees produced following the domestic technology recipe. Additionally, the results were considered in the light of the Codex Alimentarius and the Mexican standard. It was found that all of the brands fall within the limits established by these standards, being of the same order of magnitude as the foreign brands. (author)

  14. Probing electron acceleration and x-ray emission in laser-plasma accelerators

    International Nuclear Information System (INIS)

    Thaury, C.; Ta Phuoc, K.; Corde, S.; Brijesh, P.; Lambert, G.; Malka, V.; Mangles, S. P. D.; Bloom, M. S.; Kneip, S.

    2013-01-01

    While laser-plasma accelerators have demonstrated a strong potential in the acceleration of electrons up to giga-electronvolt energies, few experimental tools for studying the acceleration physics have been developed. In this paper, we demonstrate a method for probing the acceleration process. A second laser beam, propagating perpendicular to the main beam, is focused on the gas jet few nanosecond before the main beam creates the accelerating plasma wave. This second beam is intense enough to ionize the gas and form a density depletion, which will locally inhibit the acceleration. The position of the density depletion is scanned along the interaction length to probe the electron injection and acceleration, and the betatron X-ray emission. To illustrate the potential of the method, the variation of the injection position with the plasma density is studied

  15. Detection of halogenated flame retardants in polyurethane foam by particle induced X-ray emission

    International Nuclear Information System (INIS)

    Maley, Adam M.; Falk, Kyle A.; Hoover, Luke; Earlywine, Elly B.; Seymour, Michael D.; DeYoung, Paul A.; Blum, Arlene; Stapleton, Heather M.; Peaslee, Graham F.

    2015-01-01

    A novel application of particle-induced X-ray emission (PIXE) has been developed to detect the presence of chlorinated and brominated flame retardant chemicals in polyurethane foams. Traditional Gas Chromatography–Mass Spectrometry (GC–MS) methods for the detection and identification of halogenated flame retardants in foams require extensive sample preparation and data acquisition time. The elemental analysis of the halogens in polyurethane foam performed by PIXE offers the opportunity to identify the presence of halogenated flame retardants in a fraction of the time and sample preparation cost. Through comparative GC–MS and PIXE analysis of 215 foam samples, excellent agreement between the two methods was obtained. These results suggest that PIXE could be an ideal rapid screening method for the presence of chlorinated and brominated flame retardants in polyurethane foams

  16. Core-hole-induced dynamical effects in the x-ray emission spectrum of liquid methanol.

    Science.gov (United States)

    Ljungberg, M P; Zhovtobriukh, I; Takahashi, O; Pettersson, L G M

    2017-04-07

    We compute the x-ray emission spectrum of liquid methanol, with the dynamical effects that result from the creation of the core hole included in a semiclassical way. Our method closely reproduces a fully quantum mechanical description of the dynamical effects for relevant one-dimensional models of the hydrogen-bonded methanol molecules. For the liquid, we find excellent agreement with the experimental spectrum, including the large isotope effect in the first split peak. The dynamical effects depend sensitively on the initial structure in terms of the local hydrogen-bonding (H-bonding) character: non-donor molecules contribute mainly to the high-energy peak while molecules with a strong donating H-bond contribute to the peak at lower energy. The spectrum thus reflects the initial structure mediated by the dynamical effects that are, however, seen to be crucial in order to reproduce the intensity distribution of the recently measured spectrum.

  17. Interpretation of magnetic circular dichroism of X-ray emission spectra

    International Nuclear Information System (INIS)

    Takayama, Yasuhiro; Yoshida, Tetsuo; Nakamura, Satoshi; Sasaki, Naoya; Ishii, Hiroyoshi; Miyahara, Tsuneaki

    2006-01-01

    We have measured the dependence of the magnetic circular dichroism (MCD) of the X-ray emission spectra (XES) on the temperature and incident angle for a Gd thin film. The energy of the incident photon for the XES was 138.25eV, which corresponded to the resonant excitation to the 8 D 9/2 intermediate state. The dependence of the observed MCD on the temperature and incident angle was quite different from that of the magnetic moment estimated with a SQUID magnetometer. By considering the reflection, saturation effect, self-absorption effect and magnetic anisotropy of the thin film, the agreement of the two behaviors was considerably improved. This result shows that the revisions of the MCD of the XES are extremely important for the quantitative estimation of the magnetic moment from the MCD of the XES. (author)

  18. Sample preparation techniques in trace element analysis by X-ray emission spectroscopy

    International Nuclear Information System (INIS)

    Valkovic, V.

    1983-11-01

    The report, written under a research contract with the IAEA, contains a detailed presentation of the most difficult problem encountered in the trace element analysis by methods of the X-ray emission spectroscopy, namely the sample preparation techniques. The following items are covered. Sampling - with specific consideration of aerosols, water, soil, biological materials, petroleum and its products, storage of samples and their handling. Pretreatment of samples - preconcentration, ashing, solvent extraction, ion exchange and electrodeposition. Sample preparations for PIXE - analysis - backings, target uniformity and homogeneity, effects of irradiation, internal standards and specific examples of preparation (aqueous, biological, blood serum and solid samples). Sample preparations for radioactive sources or tube excitation - with specific examples (water, liquid and solid samples, soil, geological, plants and tissue samples). Finally, the problem of standards and reference materials, as well as that of interlaboratory comparisons, is discussed

  19. Particle induced x-ray emission studies of some Indian medicinal plants

    International Nuclear Information System (INIS)

    Nomita Devi, K.; Nandakumar Sarma, H.; Kumar, Sanjiv

    2007-01-01

    Medicinal herbs have been used from antiquity by humanity. This paper discusses the elemental composition and concentration of ten Indian medicinal plants investigated by particle induced X-ray emission (PIXE) technique. The accuracy and precision of the technique were assured by analyzing three Certified Standard Reference Materials -cabbage- (GBW 08504, China), wheat flour (NIST-8436) and bovine liver (NIST-1577b). The element K, Ca, Mn, Fe, Cu and Zn were found to be present in all the samples in varying concentrations. No toxic heavy metals such as As, Pb and Hg were detected in the studied plants. The range of the elemental concentrations in dry weight has been found to vary from 4.69x10 4 mg/kg to 1.81 mg/kg in the plants. The results also show that these plants contain elements of vital importance in man's metabolism and that are needed for growth and developments, prevention and heating of diseases. (author)

  20. Application of proton-induced X-ray emission technique to gunshot residue analyses

    International Nuclear Information System (INIS)

    Sen, P.; Panigrahi, N.; Rao, M.S.; Varier, K.M.; Sen, S.; Mehta, G.K.

    1982-01-01

    The proton-induced X-ray emission (PIXE) technique was applied to the identification and analysis of gunshot residues. Studies were made of the type of bullet and bullet hole identification, firearm discharge element profiles, the effect of various target backings, and hand swabbings. The discussion of the results reviews the sensitivity of the PIXE technique, its nondestructive nature, and its role in determining the distance from the gun to the victim and identifying the type of bullet used and whether a wound was made by a bullet or not. The high sensitivity of the PIXE technique, which is able to analyze samples as small as 0.1 to 1 ng, and its usefulness for detecting a variety of elements should make it particularly useful in firearms residue investigations

  1. Quantification of arsenic in activated carbon using particle induced X-ray emission

    International Nuclear Information System (INIS)

    Yadav, Nirbhay N.; Maheswaran, Saravanamuthu; Shutthanandan, Vaithiyalingam; Thevuthasan, Suntharampillai; Ngo, Huu H.; Vigneswaran, Saravanamuth

    2006-01-01

    To date, the trace elemental analysis of solids with inhomogeneous internal structure has been limited, particularly in the case of adsorbents. High-energy ion beam based particle induced X-ray emission (PIXE) is an ideal analytical tool suitable for simultaneous quantification of trace elements with high accuracy. In this study, PIXE was used to quantify arsenic in the adsorbents, granular activated carbon (GAC) and powder activated carbon (PAC). Pelletized and unmodified GAC and PAC samples were analyzed along with powder samples deposited on thin teflon filters. These sample preparation methods resulted in samples of various thicknesses and densities. PIXE measurements taken from these samples were compared to results from neutron activation analysis (NAA) and atomic absorption spectroscopy (AAS). There is a good agreement between the values from the NAA and pelletized PIXE measurements and some AAS measurements

  2. Detection of halogenated flame retardants in polyurethane foam by particle induced X-ray emission

    Energy Technology Data Exchange (ETDEWEB)

    Maley, Adam M.; Falk, Kyle A.; Hoover, Luke; Earlywine, Elly B.; Seymour, Michael D. [Department of Chemistry, Hope College, 35 E. 12th Street, Holland, MI 49423 (United States); DeYoung, Paul A. [Department of Physics, Hope College, 27 Graves Place, Holland, MI 49423 (United States); Blum, Arlene [Green Science Policy Institute, Box 5455, Berkeley, CA 94705 (United States); Stapleton, Heather M. [Nicholas School of the Environment, Duke University, LSRC Box 90328, Durham, NC 27708 (United States); Peaslee, Graham F., E-mail: peaslee@hope.edu [Department of Chemistry, Hope College, 35 E. 12th Street, Holland, MI 49423 (United States)

    2015-09-01

    A novel application of particle-induced X-ray emission (PIXE) has been developed to detect the presence of chlorinated and brominated flame retardant chemicals in polyurethane foams. Traditional Gas Chromatography–Mass Spectrometry (GC–MS) methods for the detection and identification of halogenated flame retardants in foams require extensive sample preparation and data acquisition time. The elemental analysis of the halogens in polyurethane foam performed by PIXE offers the opportunity to identify the presence of halogenated flame retardants in a fraction of the time and sample preparation cost. Through comparative GC–MS and PIXE analysis of 215 foam samples, excellent agreement between the two methods was obtained. These results suggest that PIXE could be an ideal rapid screening method for the presence of chlorinated and brominated flame retardants in polyurethane foams.

  3. Linear scans of hair strands for trace elements by proton induced x-ray emission

    International Nuclear Information System (INIS)

    Jolly, R.K.; Pehrson, G.R.; Gupta, S.K.; Buckle, D.C.; Aceto, H. Jr.

    1974-01-01

    Hair strands obtained from school children in the 10 to 12 year age group were analyzed for trace element concentration as a function of distance from the root by proton-induced x-ray emission to study the history of exposure of the donors to toxic trace metals. These samples were collected from the vicinity of a copper smelter where high levels of As, Cd, Sb, and Pb have been noted. Scans show a continual build-up of Pb as a function of distance from the root, while As shows a reproducible and distinct maximum approximately 10 cm from the root. The concentration of Zn was found to be constant in all samples (without exception) to within the uncertainties of our measurements

  4. Probing Transient Valence Orbital Changes with Picosecond Valence-to-Core X-ray Emission Spectroscopy

    DEFF Research Database (Denmark)

    March, Anne Marie; Assefa, Tadesse A.; Boemer, Christina

    2017-01-01

    We probe the dynamics of valence electrons in photoexcited [Fe(terpy)2]2+ in solution to gain deeper insight into the Fe ligand bond changes. We use hard X-ray emission spectroscopy (XES), which combines element specificity and high penetration with sensitivity to orbital structure, making...... valence orbitals to the nascent core-hole. Vtc-XES offers particular insight into the molecular orbitals directly involved in the light-driven dynamics; a change in the metal ligand orbital overlap results in an intensity reduction and a blue energy shift in agreement with our theoretical calculations...... and more subtle features at the highest energies reflect changes in the frontier orbital populations....

  5. X-ray evidence for ultra-fast outflows in AGNs

    Science.gov (United States)

    Tombesi, Francesco; Sambruna, Rita; Braito, Valentina; Reeves, James; Reynolds, Christopher; Cappi, Massimo

    2012-07-01

    X-ray evidence for massive, highly ionized, ultra-fast outflows (UFOs) has been recently reported in a number of AGNs through the detection of blue-shifted Fe XXV/XXVI absorption lines. We present the results of a comprehensive spectral analysis of a large sample of 42 local Seyferts and 5 radio galaxies observed with XMM-Newton and Suzaku. We assessed the global detection significance of the absorption lines and performed a detailed photo-ionization modeling. We find that UFOs are common phenomena, being present in >40% of the sources. Their outflow velocity distribution is in the range ˜0.03--0.3c, with mean value of ˜0.14c. The ionization parameter is very high, in the range logξ˜3--6 erg~s^{-1}~cm, and the associated column densities are also large, in the range ˜10^{22}--10^{24} cm^{-2}. Their location is constrained at ˜0.0003--0.03pc (˜10^2--10^4 r_s) from the central black hole, consistent with what is expected for accretion disk winds/outflows. The mass outflow rates are in the interval ˜0.01--1M_{⊙}~yr^{-1} and the associated mechanical power is high, in the range ˜10^{43}--10^{45} erg/s. Therefore, UFOs are capable to provide a significant contribution to the AGN cosmological feedback and their study can provide important clues on the connection between accretion disks, winds and jets.

  6. Therapeutic application of metallic nanoparticles combined with particle-induced x-ray emission effect

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong-Ki; Seo, Seung-Jun [Biomedical Engineering and Radiology, School of Medicine, Catholic University of Daegu, Daegu 705-034 (Korea, Republic of); Kim, Ki-Hong [Department of Optometry and Visual Sciences, Catholic University of Daegu, Kyungsan 712-702 (Korea, Republic of); Kim, Tae-Jeong [Applied Chemical Engineering, College of Engineering, Kyungpuk National University, Daegu 702-701 (Korea, Republic of); Chung, Myung-Hwan; Kim, Kye-Ryung [Proton Engineering Frontier Project, Korea Atomic Energy Research Institute, Daejeon 305-353 (Korea, Republic of); Yang, Tae-Keun, E-mail: jkkim@cu.ac.kr [Korea Institute of Radiological and Medical Sciences, Seoul 139-706 (Korea, Republic of)

    2010-10-22

    Metallic nanoparticles (MNP) are able to release localized x-rays when activated with a high energy proton beam by the particle-induced x-ray emission (PIXE) effect. The exploitation of this phenomenon in the therapeutic irradiation of tumors has been investigated. PIXE-based x-ray emission directed at CT26 tumor cells in vitro, when administered with either gold (average diameter 2 and 13 nm) or iron (average diameter 14 nm) nanoparticles (GNP or SNP), increased with MNP solution concentration over the range of 0.1-2 mg ml{sup -1}. With irradiation by a 45 MeV proton therapy (PT) beam, higher concentrations had a decreased cell survival fraction. An in vivo study in CT26 mouse tumor models with tumor regression assay demonstrated significant tumor dose enhancement, thought to be a result of the PIXE effect when compared to conventional PT without MNP (radiation-only group) using a 45 MeV proton beam (p < 0.02). Those receiving GNP or SNP injection doses of 300 mg kg{sup -1} body weight before proton beam therapy demonstrated 90% or 75% tumor volume reduction (TVR) in 20 days post-PT while the radiation-only group showed only 18% TVR and re-growth of tumor volume after 20 days. Higher complete tumor regression (CTR) was observed in 14-24 days after a single treatment of PT with an average rate of 33-65% for those receiving MNP compared with 25% for the radiation-only group. A lower bound of therapeutic effective MNP concentration range, in vivo, was estimated as 30-79 {mu}g g{sup -1} tissue for both gold and iron nanoparticles. The tumor dose enhancement may compensate for an increase in entrance dose associated with conventional PT when treating large, solid tumors with a spread-out Bragg peak (SOBP) technique. The use of a combined high energy Bragg peak PT with PIXE generated by MNP, or PIXE alone, may result in new treatment options for infiltrative metastatic tumors and other diffuse inflammatory diseases.

  7. Behavior of hard X-ray emission in discharges with current disruptions in the DAMAVAND and TVD tokamaks

    International Nuclear Information System (INIS)

    Farshi, E.; Amrollahy, R.; Bortnikov, A.V.; Brevnov, N.N.; Gott, Yu.V.; Shurygin, V.A.

    2001-01-01

    Results are presented from studies of the behavior of hard X-ray emission in discharges with current disruptions in the DAMAVAND and TVD tokamaks. The current disruptions are caused by either an MHD instability or the instability related to the vertical displacement of the plasma column. Experiments were conducted at a fixed value of the safety factor at the plasma boundary (q a ≅ 2.3). Experimental data show that, during a disruption caused by an MHD instability, hard X-ray emission is suppressed by this instability if the amplitude of the magnetic field fluctuations exceeds a certain level. If the disruption is caused by the instability related to the vertical displacement of the plasma column, then hard X-ray emission is observed at the instant of disruption. The experimental results show that the physical processes resulting in the generation and suppression of runaway electron beams are almost identical in large and small tokamaks

  8. On the properties of synchrotron-like X-ray emission from laser wakefield accelerated electron beams

    Science.gov (United States)

    McGuffey, C.; Schumaker, W.; Matsuoka, T.; Chvykov, V.; Dollar, F.; Kalintchenko, G.; Kneip, S.; Najmudin, Z.; Mangles, S. P. D.; Vargas, M.; Yanovsky, V.; Maksimchuk, A.; Thomas, A. G. R.; Krushelnick, K.

    2018-04-01

    The electric and magnetic fields responsible for electron acceleration in a Laser Wakefield Accelerator (LWFA) also cause electrons to radiate x-ray photons. Such x-ray pulses have several desirable properties including short duration and being well collimated with tunable high energy. We measure the scaling of this x-ray source experimentally up to laser powers greater than 100 TW. An increase in laser power allows electron trapping at a lower density as well as with an increased trapped charge. These effects resulted in an x-ray fluence that was measured to increase non-linearly with laser power. The fluence of x-rays was also compared with that produced from K-α emission resulting from a solid target interaction for the same energy laser pulse. The flux was shown to be comparable, but the LWFA x-rays had a significantly smaller source size. This indicates that such a source may be useful as a backlighter for probing high energy density plasmas with ultrafast temporal resolution.

  9. Relation between X-Ray and γ-Ray Emissions for Fermi Blazars ...

    Indian Academy of Sciences (India)

    Abstract. Using γ-ray band data detected by Fermi Large Area Tele- scope (LAT) and X-ray band data for 78 blazars, we find a medium cor- relation between X-ray and γ-ray fluxes in the average state. A medium anticorrelation is also found between X-ray (1 KeV) mean spectral index αx and γ-ray mean spectral index αγ for ...

  10. Inorganic Profiling of Amoxicillin Drugs in Ghana Using Proton Induced X-Ray Emission (Pixe) Analysis

    International Nuclear Information System (INIS)

    Abdul-Wahab, Zurika

    2017-07-01

    Induced X-ray Emission (PIXE) analysis of the amoxicillin standard reference material revealed ten (10 ) elements which include Al, S, K, Ca, V, Cr, Mn, Fe, Ni, and Zn. Sulphur was identified as the major element in the standard reference material and recorded concentration value of 396,805 ppm. Samples from Kwame Nkrumah Circle, a locally manufactured brand recorded the lowest sulphur concentrations of 251,745 ppm, compared to all drugs analysed using PIXE; imported amoxicillin (395,753 ppm) and Okaishi locally manufactured (384,710 ppm). Additionally, the elements Cr, Mn and Fe were found to be relatively higher in the Kwame Nkrumah Circle sample hence raising concerns over the quality of the Kwame Nkrumah Circle brand. When a physical parameter test was performed on all samples, all brands with the exception of Kwame Nkrumah Circle passed the disintegration and dissolution test deeming the Kwame Nkrumah Circle brand substandard. After an HPLC test was performed for all samples, it was discovered that all the drugs analysed passed the acceptance criteria (90-120%) for drugs set by the British Pharmacopoeia; with the Kwame Nkrumah Circle brand recording a value of 97% relatively lower than all the other samples which range from 113 to 117%. Sulphur as an active principle ingredient was correlated with the other identified elements. Strong correlations with correlation coefficients within the range 0.9936 – 0.9978 were found with the elements Cr, Mn, and Fe. Hence the elements S, Cr, Mn, and Fe lend themselves as element signature for amoxicillin medical drug. This was done to discover element signatures that will facilitate differentiating between genuine and counterfeit amoxicillin drugs. Considering the simplicity in sample preparation, the non-distractive nature of PIXE analysis, and also fast turn out in producing results. PIXE offers a considerable advantage when analysing antibiotic drugs on a large scale. (author)

  11. X-RAY EMISSION FROM J1446–4701, J1311–3430, AND OTHER BLACK WIDOW PULSARS

    Energy Technology Data Exchange (ETDEWEB)

    Arumugasamy, Prakash; Pavlov, George G. [Department of Astronomy and Astrophysics, 525 Davey Lab, The Pennsylvania State University, University Park, PA 16802 (United States); Garmire, Gordon P., E-mail: pxa151@ucs.psu.edu [Huntingdon Institute for X-ray Astronomy, LLC, 10677 Franks Road, Huntingdon, PA 16652 (United States)

    2015-12-01

    We present the results of detailed X-ray analysis of two black-widow pulsars (BWPs), J1446–4701 and J1311–3430. PSR J1446–4701 is a BWP with orbital parameters near the median values of the sample of known BWPs. Its X-ray emission that was detected by XMM-Newton is well characterized by a soft power-law (PL) spectrum (photon index Γ ≈ 3), and it shows no significant orbital modulations. In view of a lack of radio eclipses and an optical non-detection, the system most likely has a low orbital inclination. PSR J1311–3430 is an extreme BWP with a very compact orbit and the lowest minimum mass companion. Our Chandra data confirm the hard Γ ≈ 1.3 emission seen in previous observations. Through phase-restricted spectral analysis, we found a hint (∼2.6σ) of spectral hardening around pulsar inferior conjunction. We also provide a uniform analysis of the 12 BWPs observed with Chandra and compare their X-ray properties. Pulsars with soft, Γ > 2.5 emission seem to have lower than average X-ray and γ-ray luminosities. We do not, however, see any other prominent correlation between the pulsar’s X-ray emission characteristics and any of its other properties. The contribution of the intra-binary shock to the total X-ray emission, if any, is not discernible in this sample of pulsars with shallow observations.

  12. Efficient high-resolution X-ray emission spectrometry using synchrotron radiation

    International Nuclear Information System (INIS)

    Unterumsberger, Rainer

    2015-01-01

    The aim of the present work is to get access to high-resolution X-Ray Emission Spectrometry (XES) at nanoscaled materials, consisting of light elements and transition metals, by the increase of the sensitivity of a Wavelength-Dispersive Spectrometer (WDS) in the soft X-Ray range. The increase of the sensitivity was achieved by a refocusing of the incident radiation. With the increased sensitivity of the WDS, it was possible to determine the chemical species of different, nominal 100 nm thin titanium oxides. The combination of the refocusing optic and calibrated spectrometer enabled the detection and deconvolution of the L-fluorescence radiation of these nanoscaled titanium oxides. Due to the calibration of the spectrometer, a reliable determination of the transition probabilities of the titanium La- and Ll-fluorescence lines as a function of the chemical state is possible. To the best of my knowledge, the determination of the transition probabilities as a function of the chemical state in the soft X-Ray range has not been investigated yet. The quality of the refocusing was characterized using different diagnostic tools. Vertical full width at half maximum (FWHM) values of the focused beam between 10 μm to 20 μm and horizontal FWHM values between 12 μm and 25 μm could be achieved over an energy range of 180 eV to 1310 eV. Using calibrated photodiodes, it was possible to determine the absolute transmission of the used single bounce monocapillary as well as to monitor the absolute photon flux. By means of the refocusing, it was possible to increase the photon flux by a factor of 4.9 experimentally. The increase of the photon flux enables the analysis of nanoscaled materials with the used spectrometer. This could be shown based on the determination of the lower limit of detection of boron Ka and titanium La. In both cases, the lower limit of detection of 0.4 nm equivalent layer thickness was achieved (about 1.10 -7 g/cm 2 to 2.10 -7 g/cm 2 or 3.10 15 atoms/cm 2 to

  13. X-ray emission from stars: a sharper and deeper view of our galaxy

    International Nuclear Information System (INIS)

    Vaiana, G.S.

    1990-01-01

    This article focusses on an aspect of the Einstein Observatory x-ray stellar results which will become more completely addressed as we enter the second decade of the Einstein data reduction, as new observations finally become available, and as new satellites are being planned for the future, namely x-ray stars as a subclass of all galactic and extragalactic x-ray sources. The aim is to produce a reference stellar x-ray list. Much has been learnt about the totality of the data set and the stellar data in particular. (author)

  14. A plastic miniature x-ray emission spectrometer based on the cylindrical von Hamos geometry

    International Nuclear Information System (INIS)

    Mattern, B. A.; Seidler, G. T.; Haave, M.; Pacold, J. I.; Gordon, R. A.; Planillo, J.; Quintana, J.; Rusthoven, B.

    2012-01-01

    We present a short working distance miniature x-ray emission spectrometer (miniXES) based on the cylindrical von Hamos geometry. We describe the general design principles for the spectrometer and detail a specific implementation that covers Kβ and valence level emission from Fe. Large spatial and angular access to the sample region provides compatibility with environmental chambers, microprobe, and pump/probe measurements. The primary spectrometer structure and optic is plastic, printed using a 3-dimensional rapid-prototype machine. The spectrometer is inexpensive to construct and is portable; it can be quickly set up at any focused beamline with a tunable narrow bandwidth monochromator. The sample clearance is over 27 mm, providing compatibility with a variety of environment chambers. An overview is also given of the calibration and data processing procedures, which are implemented by a multiplatform user-friendly software package. Finally, representative measurements are presented. Background levels are below the level of the Kβ 2,5 valence emission, the weakest diagram line in the system, and photometric analysis of count rates finds that the instrument is performing at the theoretical limit.

  15. EVOLUTION AND HYDRODYNAMICS OF THE VERY BROAD X-RAY LINE EMISSION IN SN 1987A

    Energy Technology Data Exchange (ETDEWEB)

    Dewey, D.; Canizares, C. R. [MIT Kavli Institute, Cambridge, MA 02139 (United States); Dwarkadas, V. V. [Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637 (United States); Haberl, F.; Sturm, R., E-mail: dd@space.mit.edu, E-mail: vikram@oddjob.uchicago.edu [Max-Planck-Institut fuer extraterrestrische Physik, Giessenbachstrasse, Garching D-85748 (Germany)

    2012-06-20

    Observations of SN 1987A by the Chandra High Energy Transmission Grating (HETG) in 1999 and the XMM-Newton Reflection Grating Spectrometer (RGS) in 2003 show very broad (v-b) lines with a full width at half-maximum (FWHM) of order 10{sup 4} km s{sup -1}; at these times the blast wave (BW) was primarily interacting with the H II region around the progenitor. Since then, the X-ray emission has been increasingly dominated by narrower components as the BW encounters dense equatorial ring (ER) material. Even so, continuing v-b emission is seen in the grating spectra suggesting that the interaction with H II region material is ongoing. Based on the deep HETG 2007 and 2011 data sets, and confirmed by RGS and other HETG observations, the v-b component has a width of 9300 {+-} 2000 km s{sup -1} FWHM and contributes of order 20% of the current 0.5-2 keV flux. Guided by this result, SN 1987A's X-ray spectra are modeled as the weighted sum of the non-equilibrium-ionization emission from two simple one-dimensional hydrodynamic simulations; this '2 Multiplication-Sign 1D' model reproduces the observed radii, light curves, and spectra with a minimum of free parameters. The interaction with the H II region ({rho}{sub init} Almost-Equal-To 130 amu cm{sup -3}, {+-} 15 Degree-Sign opening angle) produces the very broad emission lines and most of the 3-10 keV flux. Our ER hydrodynamics, admittedly a crude approximation to the multi-D reality, gives ER densities of {approx}10{sup 4} amu cm{sup -3}, requires dense clumps ( Multiplication-Sign 5.5 density enhancement in {approx}30% of the volume), and predicts that the 0.5-2 keV flux will drop at a rate of {approx}17% per year once no new dense ER material is being shocked.

  16. X-RAY EMISSION AND DYNAMICS FROM LARGE DIAMETER SUPERBUBBLES: THE CASE OF THE N70 SUPERBUBBLE

    International Nuclear Information System (INIS)

    Rodriguez-Gonzalez, A.; Velazquez, P. F.; Esquivel, A.; Toledo-Roy, J. C.; Rosado, M.; Reyes-Iturbide, J.

    2011-01-01

    The morphology, dynamics, and thermal X-ray emission of the superbubble N70 are studied by means of three-dimensional hydrodynamic simulations carried out with the YGUAZU-A code. We consider three possible scenarios: the superbubble being the product of a single supernova remnant, of the stellar winds from an OB association, or of the joint action of stellar winds and a supernova (SN) event. Our results show that, in spite of the fact that all scenarios produce bubbles with the observed physical size, only those in which the bubble is driven by stellar winds and an SN event successfully explain the general morphology, dynamics, and X-ray luminosity of N70. Our models predict temperatures in excess of 10 8 K at the interior of the superbubble; however, the density is too low and thermal X-ray emission above 2 keV is too faint to be detected.

  17. Background radiation in inelastic X-ray scattering and X-ray emission spectroscopy. A study for Johann-type spectrometers

    Science.gov (United States)

    Paredes Mellone, O. A.; Bianco, L. M.; Ceppi, S. A.; Goncalves Honnicke, M.; Stutz, G. E.

    2018-06-01

    A study of the background radiation in inelastic X-ray scattering (IXS) and X-ray emission spectroscopy (XES) based on an analytical model is presented. The calculation model considers spurious radiation originated from elastic and inelastic scattering processes along the beam paths of a Johann-type spectrometer. The dependence of the background radiation intensity on the medium of the beam paths (air and helium), analysed energy and radius of the Rowland circle was studied. The present study shows that both for IXS and XES experiments the background radiation is dominated by spurious radiation owing to scattering processes along the sample-analyser beam path. For IXS experiments the spectral distribution of the main component of the background radiation shows a weak linear dependence on the energy for the most cases. In the case of XES, a strong non-linear behaviour of the background radiation intensity was predicted for energy analysis very close to the backdiffraction condition, with a rapid increase in intensity as the analyser Bragg angle approaches π / 2. The contribution of the analyser-detector beam path is significantly weaker and resembles the spectral distribution of the measured spectra. Present results show that for usual experimental conditions no appreciable structures are introduced by the background radiation into the measured spectra, both in IXS and XES experiments. The usefulness of properly calculating the background profile is demonstrated in a background subtraction procedure for a real experimental situation. The calculation model was able to simulate with high accuracy the energy dependence of the background radiation intensity measured in a particular XES experiment with air beam paths.

  18. Fast spectral fitting of hard X-ray bremsstrahlung from truncated power-law electron spectra

    Czech Academy of Sciences Publication Activity Database

    Brown, J. C.; Kašparová, Jana; Massone, A.M.; Piana, M.

    2008-01-01

    Roč. 486, č. 3 (2008), s. 1023-1029 ISSN 0004-6361 R&D Projects: GA ČR GP205/06/P135 Institutional research plan: CEZ:AV0Z10030501 Keywords : sun flares * X-rays * gamma rays Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 4.153, year: 2008

  19. Fast, versatile x-ray fluorescence method for measuring tin in impregnated wood

    DEFF Research Database (Denmark)

    Drabæk, I.; Christensen, Leif Højslet

    1985-01-01

    The present paper describes an energy-dispersive x-ray fluorescence method for measuring tin in bis(tri-n-butyl)tin-oxide impregnated wood. The proposed method is of the backscatter/fundamental parameter type. Its versatility, precision, and accuracy is demonstrated by analyses of eleven samples...

  20. SphinX: A Fast Solar Photometer in X-rays J. Sylwester , S. Kuzin ...

    Indian Academy of Sciences (India)

    NAS solar mission. SphinX (Solar Photometer in X-rays) will use PIN silicon detectors for high time resolution (0.01 s) measurements of the solar spectra of .... right panel of Fig. 2. In this NBF concept, three fluorescing targets illuminate a single. PIN detector. The fluorescence radiation is coming from three different pure ...

  1. Fast photoconductor CdTe detectors for synchrotron x-ray studies

    International Nuclear Information System (INIS)

    Yoo, Sung Shik; Faurie, J.P.; Huang Qiang; Rodricks, B.

    1993-09-01

    The Advanced Photon Source will be that brightest source of synchrotron x-rays when it becomes operational in 1996. During normal operation, the ring will be filled with 20 bunches of positrons with an interbunch spacing of 177 ns and a bunch width of 119 ps. To perform experiments with x-rays generated by positrons on these time scales one needs extremely high speed detectors. To achieve the necessary high speed, we are developing MBE-grown CdTe-base photoconductive position sensitive array detectors. The arrays fabricated have 64 pixels with a gap of 100 μm between pixels. The high speed response of the devices was tested using a short pulse laser. X-ray static measurements were performed using an x-ray tube and synchrotron radiation to study the device's response to flux and wavelength changes. This paper presents the response of the devices to some of these tests and discusses different physics aspects to be considered when designing high speed detectors

  2. SphinX : A fast solar Ph otometer in X -rays

    Czech Academy of Sciences Publication Activity Database

    Sylwester, J.; Kuzin, S.; Kotov, Yu. D.; Fárník, František; Reale, F.

    2008-01-01

    Roč. 29, 1-2 (2008), s. 339-343 ISSN 0250-6335 Institutional research plan: CEZ:AV0Z10030501 Keywords : X-rays * spectrophotometer * high time resolution Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 0.667, year: 2008

  3. HARD X-RAY EMISSION DURING FLARES AND PHOTOSPHERIC FIELD CHANGES

    International Nuclear Information System (INIS)

    Burtseva, O.; Petrie, G. J. D.; Pevtsov, A. A.; Martínez-Oliveros, J. C.

    2015-01-01

    We study the correlation between abrupt permanent changes of magnetic field during X-class flares observed by the Global Oscillation Network Group and Helioseismic and Magnetic Imager instruments, and the hard X-ray (HXR) emission observed by RHESSI, to relate the photospheric field changes to the coronal restructuring and investigate the origin of the field changes. We find that spatially the early RHESSI emission corresponds well to locations of the strong field changes. The field changes occur predominantly in the regions of strong magnetic field near the polarity inversion line (PIL). The later RHESSI emission does not correspond to significant field changes as the flare footpoints are moving away from the PIL. Most of the field changes start before or around the start time of the detectable HXR signal, and they end at about the same time or later than the detectable HXR flare emission. Some of the field changes propagate with speed close to that of the HXR footpoint at a later phase of the flare. The propagation of the field changes often takes place after the strongest peak in the HXR signal when the footpoints start moving away from the PIL, i.e., the field changes follow the same trajectory as the HXR footpoint, but at an earlier time. Thus, the field changes and HXR emission are spatio-temporally related but not co-spatial nor simultaneous. We also find that in the strongest X-class flares the amplitudes of the field changes peak a few minutes earlier than the peak of the HXR signal. We briefly discuss this observed time delay in terms of the formation of current sheets during eruptions

  4. Forensic analysis of tempered sheet glass by particle induced X-ray emission (PIXE)

    Energy Technology Data Exchange (ETDEWEB)

    Jisonna, L.J. [Department of Chemistry and Department of Physics, Hope College, Holland, MI 49422-9000 (United States); DeYoung, P.A., E-mail: deyoung@hope.ed [Department of Chemistry and Department of Physics, Hope College, Holland, MI 49422-9000 (United States); Ferens, J.; Hall, C.; Lunderberg, J.M.; Mears, P. [Department of Chemistry and Department of Physics, Hope College, Holland, MI 49422-9000 (United States); Padilla, D. [Department of Physics, San Diego State University, San Diego, CA 92182-1233 (United States); Peaslee, G.F. [Department of Chemistry and Department of Physics, Hope College, Holland, MI 49422-9000 (United States); Sampson, R. [Department of Physics, Columbia University, New York, NY 10027 (United States)

    2011-05-15

    Highlights: {yields} PIXE was found to give the same results for trace elements in glass as ICP. {yields} PIXE can non-destructively determine trace element concentrations in auto glass. {yields} Measured Ca, Fe, Ti, Mn, and Sr in auto glass with PIXE. -- Abstract: The elemental concentrations of five trace elements in tempered sheet glass fragments were determined using particle-induced X-ray emission (PIXE) spectrometry. The trace element concentrations for calcium, iron, manganese, strontium, and titanium are compared to those obtained by inductively-coupled plasma-atomic emission spectrometry (ICP-AES) following complete digestion by hydrofluoric acid. For these five elements, the absolute concentrations obtained by both methods are shown to agree well over a wide range of concentrations. The limits of detection for trace elements are typically lower for the ICP-AES method. However, we show that the concentrations of these five elements can be accurately measured by the PIXE method. Since PIXE is an entirely non-destructive method, there exists a niche for this technique to be used as a complement to the more sensitive ICP-AES technique in the forensic analysis of sheet glass.

  5. Line Emission and X-ray Line Polarization of Multiply Ionized Mo Ions

    Science.gov (United States)

    Petkov, E. E.; Safronova, A. S.; Kantsyrev, V. L.; Shlyaptseva, V. V.; Stafford, A.; Safronova, U. I.; Shrestha, I. K.; Schultz, K. A.; Childers, R.; Cooper, M. C.; Beiersdorfer, P.; Hell, N.; Brown, G. V.

    2016-10-01

    We present a comprehensive experimental and theoretical study of the line emission from multiply ionized Mo ions produced by two different sets of experiments: at LLNL EBIT and the pulsed power generator Zebra at UNR. Mo line emission and polarization measurements were accomplished at EBIT for the first time. In particular, benchmarking experiments at the LLNL EBIT with Mo ions produced at electron beam energies from 2.75 keV up to 15 keV allowed us to break down these very complicated spectra into spectra with only few ionization stages and to select processes that influence them as well as to measure line polarization. The EBIT data were recorded using the EBIT Calorimeter Spectrometer and a crystal spectrometer with a Ge crystal. X-ray Mo spectra and pinhole images were collected from Z-pinch plasmas produced from various wire loads. Non-LTE modeling, high-precision relativistic atomic and polarization data were used to analyze L-shell Mo spectra. The influence of different plasma processes including electron beams on Mo line radiation is summarized. This work was supported by NNSA under DOE Grant DE-NA0002954. Experiments at the NTF/UNR were funded in part by DE-NA0002075. Work at LLNL was performed under the auspices of the U.S. DOE under contract DE-AC52-07NA27344.

  6. Studies in the X-Ray Emission of Clusters of Galaxies and Other Topics

    Science.gov (United States)

    Vrtilek, Jan; Thronson, Harley (Technical Monitor)

    2001-01-01

    The paper discusses the following: (1) X-ray study of groups of galaxies with Chandra and XMM. (2) X-ray properties of point sources in Chandra deep fields. (3) Study of cluster substructure using wavelet techniques. (4) Combined study of galaxy clusters with X-ray and the S-Z effect. Groups of galaxies are the fundamental building blocks of large scale structure in the Universe. X-ray study of the intragroup medium offers a powerful approach to addressing some of the major questions that still remain about almost all aspects of groups: their ages, origins, importance of composition of various galaxy types, relations to clusters, and origin and enrichment of the intragroup gas. Long exposures with Chandra have opened new opportunities for the study of X-ray background. The presence of substructure within clusters of galaxies has substantial implications for our understanding of cluster evolution as well as fundamental questions in cosmology.

  7. The smoothing and fast Fourier transformation of experimental X-ray and neutron data from amorphous materials

    International Nuclear Information System (INIS)

    Dixon, M.; Wright, A.C.; Hutchinson, P.

    1977-01-01

    The application of fast Fourier transformation techniques to the analysis of experimental X-ray and neutron diffraction patterns from amorphous materials is discussed and compared with conventional techniques using Filon's quadrature. The fast Fourier transform package described also includes cubic spline smoothing and has been extensively tested, using model data to which statistical errors have been added by means of a pseudo-random number generator with Gaussian shaper. Neither cubic spline nor hand smoothing has much effect on the resulting transform since the noise removed is of too high a frequency. (Auth.)

  8. Soft x-ray continuum radiation transmitted through metallic filters: An analytical approach to fast electron temperature measurements

    International Nuclear Information System (INIS)

    Delgado-Aparicio, L.; Hill, K.; Bitter, M.; Tritz, K.; Kramer, T.; Stutman, D.; Finkenthal, M.

    2010-01-01

    A new set of analytic formulas describes the transmission of soft x-ray continuum radiation through a metallic foil for its application to fast electron temperature measurements in fusion plasmas. This novel approach shows good agreement with numerical calculations over a wide range of plasma temperatures in contrast with the solutions obtained when using a transmission approximated by a single-Heaviside function [S. von Goeler et al., Rev. Sci. Instrum. 70, 599 (1999)]. The new analytic formulas can improve the interpretation of the experimental results and thus contribute in obtaining fast temperature measurements in between intermittent Thomson scattering data.

  9. An Optical and Infrared Time-domain Study of the Supergiant Fast X-Ray Transient Candidate IC 10 X-2

    Science.gov (United States)

    Kwan, Stephanie; Lau, Ryan M.; Jencson, Jacob; Kasliwal, Mansi M.; Boyer, Martha L.; Ofek, Eran; Masci, Frank; Laher, Russ

    2018-03-01

    We present an optical and infrared (IR) study of IC 10 X-2, a high-mass X-ray binary in the galaxy IC 10. Previous optical and X-ray studies suggest that X-2 is a Supergiant Fast X-ray Transient: a large-amplitude (factor of ∼100), short-duration (hours to weeks) X-ray outburst on 2010 May 21. We analyze R- and g-band light curves of X-2 from the intermediate Palomar Transient Factory taken between 2013 July 15 and 2017 February 14 that show high-amplitude (≳1 mag), short-duration (≲8 days) flares and dips (≳0.5 mag). Near-IR spectroscopy of X-2 from Palomar/TripleSpec show He I, Paschen-γ, and Paschen-β emission lines with similar shapes and amplitudes as those of luminous blue variables (LBVs) and LBV candidates (LBVc). Mid-IR colors and magnitudes from Spitzer/Infrared Array Camera photometry of X-2 resemble those of known LBV/LBVcs. We suggest that the stellar companion in X-2 is an LBV/LBVc and discuss possible origins of the optical flares. Dips in the optical light curve are indicative of eclipses from optically thick clumps formed in the winds of the stellar counterpart. Given the constraints on the flare duration (0.02–0.8 days) and the time between flares (15.1 ± 7.8 days), we estimate the clump volume filling factor in the stellar winds, f V , to be 0.01interpret the origin of the optical flares as the accretion of clumps formed in the winds of an LBV/LBVc onto the compact object.

  10. Multiwavelength Photometric Imaging of X-Ray and EUV Emission from Comet P/Tempel-Tuttle 1998

    Science.gov (United States)

    Lisse, Carey M.

    2004-01-01

    The unexpected discovery of x-ray emission from Comet Hyakutake in March 1996 (Lisse et ai. 1996) has produced a number of questions about the physical mechanism producing the radiation. The original detection and subsequent observations (Dennerl et ai. 1997, Mumma et al. 1997, Krasnopolsky et al. 1998, Owens et al. 1998. Lisse et al. 1999) have shown that the very soft (best fit thermal bremsstrahlung model kT approx. 0.2 keV) emission is due to an interaction between the solar wind and the comet's atmosphere. Using the results fiom the 15 comets detected to date in x-rays, we report on the latest results on cometary x-ray emission, including new results from Chandra and XMM. As-observed morphologies, spectra, and light curves will be discussed. Our emphasis will be on understanding the physical mechanism producing the emission, and using this to determine the nature of the cometary coma, the structure of the solar wind in the heliosphere, and the source of the local soft x-ray background. This work has been graciously supported by grants from the NASA Planetary Astronomy and Astrophysical Data Programs.

  11. The quantitative determination of trace elements in giant unicellular plants by particle-induced X-ray emission

    International Nuclear Information System (INIS)

    Navarrete-Dominguez, V.R.; Yoshihara, K.; Tanaka, N.

    1982-01-01

    Particle-induced X-ray emission (PIXE) was applied for the determination of trace elements in biologically interesting materials, giant unicellular plants. It was found that the PIXE method had advantages in multi-element trace analysis of a single cell of the sample plant. (author)

  12. NuSTAR detection of high-energy X-ray emission and rapid variability from sagittarius A* flares

    DEFF Research Database (Denmark)

    Barrière, Nicolas M.; Tomsick, John A.; Baganoff, Frederick K.

    2014-01-01

    Sagittarius A* harbors the supermassive black hole that lies at the dynamical center of our Galaxy. Sagittarius A* spends most of its time in a low luminosity emission state but flares frequently in the infrared and X-ray, increasing up to a few hundred fold in brightness for up to a few hours at...

  13. X-Ray Emission Spectrometer Design with Single-Shot Pump-Probe and Resonant Excitation Capabilities

    Energy Technology Data Exchange (ETDEWEB)

    Spoth, Katherine; /SUNY, Buffalo /SLAC

    2012-08-28

    Core-level spectroscopy in the soft X-ray regime is a powerful tool for the study of chemical bonding processes. The ultrafast, ultrabright X-ray pulses generated by the Linac Coherent Light Source (LCLS) allow these reactions to be studied in greater detail than ever before. In this study, we investigated a conceptual design of a spectrometer for the LCLS with imaging in the non-dispersive direction. This would allow single-shot collection of X-ray emission spectroscopy (XES) measurements with varying laser pump X-ray probe delay or a variation of incoming X-ray energy over the illuminated area of the sample. Ray-tracing simulations were used to demonstrate how the components of the spectrometer affect its performance, allowing a determination of the optimal final design. These simulations showed that the spectrometer's non-dispersive focusing is extremely sensitive to the size of the sample footprint; the spectrometer is not able to image a footprint width larger than one millimeter with the required resolution. This is compatible with a single shot scheme that maps out the laser pump X-ray probe delay in the non-dispersive direction as well as resonant XES applications at normal incidence. However, the current capabilities of the Soft X-Ray (SXR) beamline at the LCLS do not produce the required energy range in a small enough sample footprint, hindering the single shot resonant XES application at SXR for chemical dynamics studies at surfaces. If an upgraded or future beamline at LCLS is developed with lower monochromator energy dispersion the width can be made small enough at the required energy range to be imaged by this spectrometer design.

  14. A Chandra Survey of Milky Way Globular Clusters. I. Emissivity and Abundance of Weak X-Ray Sources

    Science.gov (United States)

    Cheng, Zhongqun; Li, Zhiyuan; Xu, Xiaojie; Li, Xiangdong

    2018-05-01

    Based on archival Chandra data, we have carried out an X-ray survey of 69, or nearly half the known population of, Milky Way globular clusters (GCs), focusing on weak X-ray sources, mainly cataclysmic variables (CVs) and coronally active binaries (ABs). Using the cumulative X-ray luminosity per unit stellar mass (i.e., X-ray emissivity) as a proxy of the source abundance, we demonstrate a paucity (lower by 41% ± 27% on average) of weak X-ray sources in most GCs relative to the field, which is represented by the Solar Neighborhood and Local Group dwarf elliptical galaxies. We also revisit the mutual correlations among the cumulative X-ray luminosity (L X), cluster mass (M), and stellar encounter rate (Γ), finding {L}{{X}}\\propto {M}0.74+/- 0.13, {L}{{X}}\\propto {{{Γ }}}0.67+/- 0.07 and {{Γ }}\\propto {M}1.28+/- 0.17. The three quantities can further be expressed as {L}{{X}}\\propto {M}0.64+/- 0.12 {{{Γ }}}0.19+/- 0.07, which indicates that the dynamical formation of CVs and ABs through stellar encounters in GCs is less dominant than previously suggested, and that the primordial formation channel has a substantial contribution. Taking these aspects together, we suggest that a large fraction of primordial, soft binaries have been disrupted in binary–single or binary–binary stellar interactions before they could otherwise evolve into X-ray-emitting close binaries, whereas the same interactions also have led to the formation of new close binaries. No significant correlations between {L}{{X}}/{L}K and cluster properties, including dynamical age, metallicity, and structural parameters, are found.

  15. Soft X-ray emission spectroscopy of liquids and lithium battery materials

    International Nuclear Information System (INIS)

    Augustsson, Andreas

    2004-01-01

    Lithium ion insertion into electrode materials is commonly used in rechargeable battery technology. The insertion implies changes in both the crystal structure and the electronic structure of the electrode material. Side-reactions may occur on the surface of the electrode which is exposed to the electrolyte and form a solid electrolyte interface (SEI). The understanding of these processes is of great importance for improving battery performance. The chemical and physical properties of water and alcohols are complicated by the presence of strong hydrogen bonding. Various experimental techniques have been used to study geometrical structures and different models have been proposed to view the details of how these liquids are geometrically organized by hydrogen bonding. However, very little is known about the electronic structure of these liquids, mainly due to the lack of suitable experimental tools. In this thesis examples of studies of lithium battery electrodes and liquid systems using soft x-ray emission spectroscopy will be presented. Monochromatized synchrotron radiation has been used to accomplish selective excitation, in terms of energy and polarization. The electronic structure of graphite electrodes has been studied, before and after lithium intercalation. Changes in the electronic structure upon lithiation due to transfer of electrons into the graphite π-bands have been observed. Transfer of electrons in to the 3d states of transition metal oxides upon lithiation have been studied, through low energy excitations as dd- and charge transfer-excitations. A SEI was detected on cycled graphite electrodes. By the use of selective excitation different carbon sites were probed in the SEI. The local electronic structure of water, methanol and mixtures of the two have been examined using a special liquid cell, to separate the liquid from the vacuum in the experimental chamber. Results from the study of liquid water showed a strong influence on the 3a1 molecular

  16. Providing x-rays

    International Nuclear Information System (INIS)

    Mallozzi, P.J.; Epstein, H.M.

    1985-01-01

    This invention provides an apparatus for providing x-rays to an object that may be in an ordinary environment such as air at approximately atmospheric pressure. The apparatus comprises: means (typically a laser beam) for directing energy onto a target to produce x-rays of a selected spectrum and intensity at the target; a fluid-tight enclosure around the target; means for maintaining the pressure in the first enclosure substantially below atmospheric pressure; a fluid-tight second enclosure adjoining the first enclosure, the common wall portion having an opening large enough to permit x-rays to pass through but small enough to allow the pressure reducing means to evacuate gas from the first enclosure at least as fast as it enters through the opening; the second enclosure filled with a gas that is highly transparent to x-rays; the wall of the second enclosure to which the x-rays travel having a portion that is highly transparent to x-rays (usually a beryllium or plastic foil), so that the object to which the x-rays are to be provided may be located outside the second enclosure and adjacent thereto and thus receive the x-rays substantially unimpeded by air or other intervening matter. The apparatus is particularly suited to obtaining EXAFS (extended x-ray fine structure spectroscopy) data on a material

  17. Multielement analysis of minerals from Madagascar by X-ray emission induced by protons and gamma rays

    International Nuclear Information System (INIS)

    Rakotoarisoa, C.

    1990-12-01

    This study is a part of a large multidisciplinary program for the study of soil formation in the south east of Madagascar near the uranothorianite deposit of Tranomaro explaining the particular interest for rare earths, uranium and thorium. X-ray emission principles and physical processes of a X-ray spectra are briefly recalled. The choice of analysis method depends upon sensitivity simplicity and rapidity. Experimental techniques are described and results obtained are discussed. Methods used for qualitative and quantitative interpretation of spectra are exposed. In conclusion performance and limits of the method are examined [fr

  18. Cross section for induced L X-ray emission by protons of energy <400 keV

    International Nuclear Information System (INIS)

    Mohan, Harsh; Jain, Arvind Kumar; Kaur, Mandeep; Singh, Parjit S.; Sharma, Sunita

    2014-01-01

    In performing ion beam analysis, cross section for induced L X-ray emission plays a crucial role. There are different approaches by which these can be found experimentally or can be calculated theoretically based on various models. L X-ray production cross sections for Bi with protons in the energy range 260–400 keV at the interval of 20 keV are measured. These are compared with calculations obtained on the basis of current prevailing theories ECPSSR and ECPSSR-UA. Their importance in understanding this phenomenon and existing arguments in this regard will be highlighted

  19. Atomic imaging by x-ray-fluorescence holography and electron-emission holography: A comparative theoretical study

    International Nuclear Information System (INIS)

    Len, P.M.; Thevuthasan, S.; Fadley, C.S.; Kaduwela, A.P.; Van Hove, M.A.

    1994-01-01

    We consider from a theoretical viewpoint the direct imaging of atoms at and near the surfaces of solids by both x-ray-fluorescence holography (XFH) and electron-emission holography (EEH). The more ideal nature of x-ray scattering makes XFH images superior to those in single-energy EEH. The overlap of real and twin features for pairs of atoms at ±a can cause their XFH or EEH atomic images to cancel for certain combinations of wave vector and |a|. The relative merits of XFH and EEH for structure studies are considered

  20. A LINK BETWEEN X-RAY EMISSION LINES AND RADIO JETS IN 4U 1630-47?

    Energy Technology Data Exchange (ETDEWEB)

    Neilsen, Joseph [Department of Astronomy, Boston University, Boston, MA 02215 (United States); Coriat, Mickaël [Department of Astronomy, University of Cape Town, Private Bag X3, Rondebosch 7701 (South Africa); Fender, Rob; Broderick, Jess W. [Department of Physics, Oxford University, Oxford OX1 3RH (United Kingdom); Lee, Julia C. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Ponti, Gabriele [Max Planck Institute fur Extraterrestriche Physik, D-85748 Garching (Germany); Tzioumis, Anastasios K.; Edwards, Philip G., E-mail: neilsenj@bu.edu [CSIRO Astronomy and Space Science, Australia Telescope National Facility, P.O. Box 76, Epping, NSW 1710 (Australia)

    2014-03-20

    Recently, Díaz Trigo et al. reported an XMM-Newton detection of relativistically Doppler-shifted emission lines associated with steep-spectrum radio emission in the stellar-mass black hole candidate 4U 1630-47 during its 2012 outburst. They interpreted these lines as indicative of a baryonic jet launched by the accretion disk. Here we present a search for the same lines earlier in the same outburst using high-resolution X-ray spectra from the Chandra HETGS. While our observations (eight months prior to the XMM-Newton campaign) also coincide with detections of steep spectrum radio emission by the Australia Telescope Compact Array, we find no evidence for any relativistic X-ray emission lines. Indeed, despite ∼5 × brighter radio emission, our Chandra spectra allow us to place an upper limit on the flux in the blueshifted Fe XXVI line that is ≳ 20 × weaker than the line observed by Díaz Trigo et al. We explore several scenarios that could explain our differing results, including variations in the geometry of the jet or a mass-loading process or jet baryon content that evolves with the accretion state of the black hole. We also consider the possibility that the radio emission arises in an interaction between a jet and the nearby interstellar medium, in which case the X-ray emission lines might be unrelated to the radio emission.

  1. A LINK BETWEEN X-RAY EMISSION LINES AND RADIO JETS IN 4U 1630-47?

    International Nuclear Information System (INIS)

    Neilsen, Joseph; Coriat, Mickaël; Fender, Rob; Broderick, Jess W.; Lee, Julia C.; Ponti, Gabriele; Tzioumis, Anastasios K.; Edwards, Philip G.

    2014-01-01

    Recently, Díaz Trigo et al. reported an XMM-Newton detection of relativistically Doppler-shifted emission lines associated with steep-spectrum radio emission in the stellar-mass black hole candidate 4U 1630-47 during its 2012 outburst. They interpreted these lines as indicative of a baryonic jet launched by the accretion disk. Here we present a search for the same lines earlier in the same outburst using high-resolution X-ray spectra from the Chandra HETGS. While our observations (eight months prior to the XMM-Newton campaign) also coincide with detections of steep spectrum radio emission by the Australia Telescope Compact Array, we find no evidence for any relativistic X-ray emission lines. Indeed, despite ∼5 × brighter radio emission, our Chandra spectra allow us to place an upper limit on the flux in the blueshifted Fe XXVI line that is ≳ 20 × weaker than the line observed by Díaz Trigo et al. We explore several scenarios that could explain our differing results, including variations in the geometry of the jet or a mass-loading process or jet baryon content that evolves with the accretion state of the black hole. We also consider the possibility that the radio emission arises in an interaction between a jet and the nearby interstellar medium, in which case the X-ray emission lines might be unrelated to the radio emission

  2. X-ray emission due to interaction of SN1987A ejecta with its progenitor's stellar-wind matter

    International Nuclear Information System (INIS)

    Masai, Kuniaki.

    1990-06-01

    The progenitor of the supernova 1987A, Sk-69 202 probably had lost a considerable amount of mass in its stellar wind in the past evolutionary track through a red supergiant to a blue supergiant. In about 10 years, the expanding ejecta of SN1987A will catch up to collide with the wind matter ejected in the red supergiant phase. Shocks due to the collision will heat up the ejecta and the wind matter to cause an enhancement of thermal X-ray emission lasting for several decades. We predict the X-ray light curve and the spectrum as well as the epoch of the enhancement intending to encourage future X-ray observations, which will give a clue for the study of such peculiar stellar evolution with a blueward transition as Sk-69 202. (author)

  3. Development of a PIXE (Particle Induced X-ray Emission) analysis device using an extracted proton beam

    International Nuclear Information System (INIS)

    Saidi, A.

    1989-01-01

    The experimental device described allows the extention of the PIXE (Particle Induced X-ray Emission) method to the analysis, by means of proton beams, of solid or liquid samples, which can not be analyzed under vacuum conditions. The homogeneity of the surfaces to be analysed and elements (in the atmosphere) which absorb X-rays must be taken into account. Liquid samples do not need special care. The results show that: at high energies, the extracted beam sensibility is of the same order of magnitude as those obtained under vacuum; at low energies, the performance under vacuum conditions is better. The particles energy losses, at the exit membrane and in the outer atmosphere, decrease the X-rays production efficiency [fr

  4. X-ray emission in heavy-ion collisions. Progress report, April 1, 1980-February 28, 1981

    International Nuclear Information System (INIS)

    Watson, R.L.

    1981-03-01

    During the past year, work on x-ray emission in heavy-ion collisions has concentrated on the following topics: environmental influences on the Kα x-ray spectra of 65-MeV sulfur ions traveling in solids; multiplet structure of few-electron sulfur ions; multiplet structure of Mg Kα x-ray satellites; polarization of 1s2p→1s 2 transitions in He-like sulfur ions; and interatomic electron transfer in ionic fluorine compounds following 1s2p vacancy production. Among the most significant accomplishments of the program was a study of the dependence of dynamic screening energy shifts on electron density. It was found that the shifts measured for the 2 1 P→1 1 S and 2 2 P→1 2 S x-ray transitions of He- and H-like sulfur ions (respectively) were in remarkably good agreement with theoretical expectations. Another interesting discovery evolved from measurements of fluorine Kα x-ray spectra for the alkali metal and alkaline earth fluorides using 5.5-MeV He + ions. The systematics of these spectra provide the first evidence for direct electron transfer between inner levels of neighboring atoms in a solid. 10 figures, 3 tables

  5. Correlation of electron beams and hard x-ray emissions in ISTTOK Tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Jakubowski, L.; Malinowski, K.; Sadowski, M.J.; Zebrowski, J.; Rabinski, M.; Jakubowski, M.J. [National Centre for Nuclear Research (NCBJ), Otwock (Poland); Plyusnin, V.V.; Fernandes, H.; Silva, C.; Duarte, P. [Association Euratom/IST, Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, Lisboa (Portugal)

    2013-11-15

    The paper reports on experimental studies of electron beams in the ISTTOK tokamak, those were performed by means of an improved four-channel detector. The Cherenkov-type detector measuring head was equipped with four radiators made of two types of alumina-nitrate (AlN) poly-crystals: machinable and translucent ones, both of 10 mm in diameter and 2.5 mm in thickness. The movable support that enabled the whole detectors to be placed inside the tokamak vacuum chamber, at chosen positions along the ISTTOK minor radius. Since the electron energy distribution is one of the most important characteristics of tokamak plasmas, the main aim of the study was to perform estimations of an energy spectrum of the recorded electrons. For this purpose the radiators were coated with molybdenum (Mo) layers of different thickness. The technique based on the use of Cherenkov-type detectors enabled the detection of fast electrons (of energy above 66 keV) and determination of their spatial and temporal characteristics in the ISTTOK experiment. Measurements of hard X-rays (HXR), which were emitted during ISTTOK discharges, have also been performed. Particular attention was paid to the correlation measurements of HXR pulses with run-away electron beams. (copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  6. Analysis of structural materials for fast-breeder reactors by X-ray fluorescence spectrometry

    International Nuclear Information System (INIS)

    Roca, M.; Diaz-Guerra, J.P.

    1978-01-01

    A procedure for the X-ray spectrometric determination of Co, Cr, Cu, Mn, Mo, Nb, Ni, P, S, Si and Ti in stainless steels and some nickel-base alloys, such as incoloy-800, is described. The use of different sets of standards has allowed the calculation of the inter-element influence coefficients for the correction of matrix effects, making the method suited for wide concentration range determinations. The efficiency of X-ray tubes with Cr and W targets has been studied, the former allowing the determination of all the above-named elements. The average relative error is 3.7%, except for P and S, where the determinations are semiquantitative. The use of a programmable spectrometer interfaced with a 16 K computer facilitates considerably the treatment of data with a proper mathematic model and furthermore provides an automatic performance of the analyses. (author)

  7. Diagnosing high density, fast-evolving plasmas using x-ray lasers

    International Nuclear Information System (INIS)

    Cauble, R.; Da Silva, L.B.; Barbee, T.W. Jr.

    1994-09-01

    As x-ray laser (XRL) research has matured, it has become possible to reliably utilize XRLs for applications in the laboratory. Laser coherence, high brightness and short pulse duration all make the XRL a unique tool for the diagnosis of laboratory plasmas. The high brightness of XRLs makes them well-suited for imaging and for interferometry when used in conjunction with multilayer mirrors and beamsplitters. We have utilized a soft x-ray laser in such an imaging system to examine laser-produced plasmas using radiography, moire deflectometry, and interferometry. Radiography experiments yield 100-200 ps snapshots of laser driven foils at a resolution of 1-2 μm. Moire deflectometry with an XRL has been used to probe plasmas at higher density than by optical means. Interferograms, which allow direct measurement of electron density in laser plasmas, have been obtained with this system

  8. Fast scattering simulation tool for multi-energy x-ray imaging

    Energy Technology Data Exchange (ETDEWEB)

    Sossin, A., E-mail: artur.sossin@cea.fr [CEA-LETI MINATEC Grenoble, F-38054 Grenoble (France); Tabary, J.; Rebuffel, V. [CEA-LETI MINATEC Grenoble, F-38054 Grenoble (France); Létang, J.M.; Freud, N. [Université de Lyon, CREATIS, CNRS UMR5220, Inserm U1044, INSA-Lyon, Université Claude Bernard Lyon 1, Centre Léon Bérard (France); Verger, L. [CEA-LETI MINATEC Grenoble, F-38054 Grenoble (France)

    2015-12-01

    A combination of Monte Carlo (MC) and deterministic approaches was employed as a means of creating a simulation tool capable of providing energy resolved x-ray primary and scatter images within a reasonable time interval. Libraries of Sindbad, a previously developed x-ray simulation software, were used in the development. The scatter simulation capabilities of the tool were validated through simulation with the aid of GATE and through experimentation by using a spectrometric CdTe detector. A simple cylindrical phantom with cavities and an aluminum insert was used. Cross-validation with GATE showed good agreement with a global spatial error of 1.5% and a maximum scatter spectrum error of around 6%. Experimental validation also supported the accuracy of the simulations obtained from the developed software with a global spatial error of 1.8% and a maximum error of around 8.5% in the scatter spectra.

  9. Theoretical estimation of proton induced X-ray emission yield of the trace elements present in the lung and breast cancer

    International Nuclear Information System (INIS)

    Manjunatha, H.C.; Sowmya, N.

    2013-01-01

    X-rays may be produced following the excitation of target atoms induced by an energetic incident ion beam of protons. Proton induced X-ray emission (PIXE) analysis has been used for many years for the determination of elemental composition of materials using X-rays. Recent interest in the proton induced X-ray emission cross section has arisen due to their importance in the rapidly expanding field of PIXE analysis. One of the steps in the analysis is to fit the measured X-ray spectrum with theoretical spectrum. The theoretical cross section and yields are essential for the evaluation of spectrum. We have theoretically evaluated the PIXE cross sections for trace elements in the lung and breast cancer tissues such as Cl, K, Ca,Ti, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Br, Rb, P, S, Sr, Hg and Pb. The estimated cross section is used in the evaluation of Proton induced X-ray emission spectrum for the given trace elements.We have also evaluated the Proton induced X-ray emission yields in the thin and thick target of the given trace elements. The evaluated Proton induced X-ray emission cross-section, spectrum and yields are graphically represented. Some of these values are also tabulated. Proton induced X-ray emission cross sections and a yield for the given trace elements varies with the energy. PIXE yield depends on a real density and does not on thickness of the target. (author)

  10. X-RAY EMISSION FROM THE DOUBLE-BINARY OB-STAR SYSTEM QZ CAR (HD 93206)

    International Nuclear Information System (INIS)

    Parkin, E. R.; Naze, Y.; Rauw, G.; Broos, P. S.; Townsley, L. K.; Pittard, J. M.; Moffat, A. F. J.; Oskinova, L. M.; Waldron, W. L.

    2011-01-01

    X-ray observations of the double-binary OB-star system QZ Car (HD 93206) obtained with the Chandra X-ray Observatory over a period of roughly 2 years are presented. The respective orbits of systems A (O9.7 I+b2 v, P A = 21 days) and B (O8 III+o9 v, P B = 6 days) are reasonably well sampled by the observations, allowing the origin of the X-ray emission to be examined in detail. The X-ray spectra can be well fitted by an attenuated three-temperature thermal plasma model, characterized by cool, moderate, and hot plasma components at kT ≅ 0.2, 0.7, and 2 keV, respectively, and a circumstellar absorption of ≅0.2 x 10 22 cm -2 . Although the hot plasma component could be indicating the presence of wind-wind collision shocks in the system, the model fluxes calculated from spectral fits, with an average value of ≅7 x 10 -13 erg s -1 cm -2 , do not show a clear correlation with the orbits of the two constituent binaries. A semi-analytical model of QZ Car reveals that a stable momentum balance may not be established in either system A or B. Yet, despite this, system B is expected to produce an observed X-ray flux well in excess of the observations. If one considers the wind of the O8 III star to be disrupted by mass transfer, the model and observations are in far better agreement, which lends support to the previous suggestion of mass transfer in the O8 III + o9 v binary. We conclude that the X-ray emission from QZ Car can be reasonably well accounted for by a combination of contributions mainly from the single stars and the mutual wind-wind collision between systems A and B.

  11. Ultrasonic acoustic levitation for fast frame rate X-ray protein crystallography at room temperature

    Science.gov (United States)

    Tsujino, Soichiro; Tomizaki, Takashi

    2016-05-01

    Increasing the data acquisition rate of X-ray diffraction images for macromolecular crystals at room temperature at synchrotrons has the potential to significantly accelerate both structural analysis of biomolecules and structure-based drug developments. Using lysozyme model crystals, we demonstrated the rapid acquisition of X-ray diffraction datasets by combining a high frame rate pixel array detector with ultrasonic acoustic levitation of protein crystals in liquid droplets. The rapid spinning of the crystal within a levitating droplet ensured an efficient sampling of the reciprocal space. The datasets were processed with a program suite developed for serial femtosecond crystallography (SFX). The structure, which was solved by molecular replacement, was found to be identical to the structure obtained by the conventional oscillation method for up to a 1.8-Å resolution limit. In particular, the absence of protein crystal damage resulting from the acoustic levitation was carefully established. These results represent a key step towards a fully automated sample handling and measurement pipeline, which has promising prospects for a high acquisition rate and high sample efficiency for room temperature X-ray crystallography.

  12. Development of an ultra-fast X-ray camera using hybrid pixel detectors

    International Nuclear Information System (INIS)

    Dawiec, A.

    2011-05-01

    The aim of the project whose work described in this thesis is part, was to design a high-speed X-ray camera using hybrid pixels applied to biomedical imaging and for material science. As a matter of fact the hybrid pixel technology meets the requirements of these two research fields, particularly by providing energy selection and low dose imaging capabilities. In this thesis, high frame rate X-ray imaging based on the XPAD3-S photons counting chip is presented. Within a collaboration between CPPM, ESRF and SOLEIL, three XPAD3 cameras were built. Two of them are being operated at the beamline of the ESRF and SOLEIL synchrotron facilities and the third one is embedded in the PIXSCAN II irradiation setup of CPPM. The XPAD3 camera is a large surface X-ray detector composed of eight detection modules of seven XPAD3-S chips each with a high-speed data acquisition system. The readout architecture of the camera is based on the PCI Express interface and on programmable FPGA chips. The camera achieves a readout speed of 240 images/s, with maximum number of images limited by the RAM memory of the acquisition PC. The performance of the device was characterized by carrying out several high speed imaging experiments using the PIXSCAN II irradiation setup described in the last chapter of this thesis. (author)

  13. UPPER LIMITS ON PULSED RADIO EMISSION FROM THE 6.85 s X-RAY PULSAR XTE J0103-728 IN THE SMALL MAGELLANIC CLOUD

    International Nuclear Information System (INIS)

    Crawford, Fronefield; Devour, Brian M.; Takacs, Brian P.; Lorimer, Duncan R.; Kondratiev, Vladislav I.

    2009-01-01

    X-ray pulsations with a 6.85 s period were recently detected in the Small Magellanic Cloud (SMC) and were subsequently identified as originating from the Be/X-ray binary system XTE J0103-728. The recent localization of the source of the X-ray emission has made a targeted search for radio pulsations from this source possible. The detection of pulsed radio emission from XTE J0103-728 would make it only the second system after PSR B1259-63 that is both a Be/X-ray binary and a radio pulsar. We observed XTE J0103-728 in 2008 February with the Parkes 64 m radio telescope soon after the identification of the source of X-ray pulsations was reported in order to search for corresponding radio pulsations. We used a continuous 6.4 hr observation with a 256 MHz bandwidth centered at 1390 MHz using the center beam of the Parkes multibeam receiver. In the subsequent data analysis, which included a folding search, a Fourier search, a fast-folding algorithm search, and a single pulse search, no pulsed signals were found for trial dispersion measures (DMs) between 0 and 800 pc cm -3 . This DM range easily encompasses the expected values for sources in the SMC. We place an upper limit of ∼45 mJy kpc 2 on the luminosity of periodic radio emission from XTE J0103-728 at the epoch of our observation, and we compare this limit to a range of luminosities measured for PSR B1259-63, the only Be/X-ray binary currently known to emit radio pulses. We also compare our limit to the radio luminosities of neutron stars having similarly long spin periods to XTE J0103-728. Since the radio pulses from PSR B1259-63 are eclipsed and undetectable during the portion of the orbit near periastron, repeated additional radio search observations of XTE J0103-728 may be valuable if it is undergoing similar eclipsing and if such observations are able to sample the orbital phase of this system well.

  14. Hard X-ray Emission from Galaxy Clusters Observed with INTEGRAL and Prospects for Simbol-X

    Science.gov (United States)

    Eckert, D.; Paltani, S.; Courvoisier, T. J.-L.

    2009-05-01

    Some galaxy clusters are known to contain a large population of relativistic electrons, which produce radio emission through synchrotron radiation. Therefore, it is expected that inverse-Compton scattering of the relativistic electrons with the CMB produce non-thermal emission which should be observable in the hard X-ray domain. Here we focus on the recent results by INTEGRAL, which shed a new light on the non-thermal emission thanks to its angular resolution and sensitivity in the hard X-ray range. We also present the exciting prospects in this field for Simbol-X, which will allow us to detect the non-thermal emission in a number of clusters and map the magnetic field throughout the intra-cluster medium.

  15. DETECTION OF HIGH-ENERGY GAMMA-RAY EMISSION DURING THE X-RAY FLARING ACTIVITY IN GRB 100728A

    International Nuclear Information System (INIS)

    Abdo, A. A.; Ackermann, M.; Ajello, M.; Bechtol, K.; Berenji, B.; Blandford, R. D.; Borgland, A. W.; Baldini, L.; Bellazzini, R.; Bregeon, J.; Ballet, J.; Barbiellini, G.; Baring, M. G.; Bastieri, D.; Bhat, P. N.; Bissaldi, E.; Bonamente, E.; Bonnell, J.; Bouvier, A.; Brigida, M.

    2011-01-01

    We present the simultaneous Swift and Fermi observations of the bright GRB 100728A and its afterglow. The early X-ray emission is dominated by a vigorous flaring activity continuing until 1 ks after the burst. In the same time interval, high-energy emission is significantly detected by the Fermi/Large Area Telescope. Marginal evidence of GeV emission is observed up to later times. We discuss the broadband properties of this burst within both the internal and external shock scenarios, with a particular emphasis on the relation between X-ray flares, the GeV emission, and a continued long-duration central engine activity as their power source.

  16. Applications of particle induced X-ray emission analysis to ambient aerosol studies

    International Nuclear Information System (INIS)

    Lannefors, H.

    1982-01-01

    The characteristics of Particle Induced X-ray Emission (PIXE) analysis in conjunction with different ambient aerosol samplers have been studied. Correction factors have been calculated for homogeneous and inhomogeneous rural and urban aerosol samples. The Nuclepore two stage filter sampler provided the most useful combination of the resolution and particle size fractionation in urban, rural and remote environments. The PIXE-analysis technique in combination with different samplers was employed in aerosol composition studies in rural and remote environments. Particular emphasis was laid on studies of aerosol long range transport. Based on air mass trajectory analysis and aerosol composition measurements the foreign contribution in southern Sweden was estimated to be 70 - 80% for S and Pb but only 30 - 50% for V and Ni. The spatial and temporal extension of a long range transport episode was studied using high time resolution continuous filter samplers in a network in southern Sweden. The variation in the concentration levels of sulphur agreed well with changes in the air mass history. Arctic summer elemental concentration levels as measured during the Swedish YMER-80 icebreaker expedition were typically one order of magnitude lower than Arctic winter levels. The combination of chemical information, optical properties and size distribution data supports the hypothesis of long range transport of air pollution into the Arctic especially during the winter. This takes place during the winter season because the Polar front is further south making conditions for long range transport up to the Arctic more favourable. (Auth.)

  17. Composition of Renaissance paint layers: simultaneous particle induced X-ray emission and backscattering spectrometry.

    Science.gov (United States)

    de Viguerie, L; Beck, L; Salomon, J; Pichon, L; Walter, Ph

    2009-10-01

    Particle induced X-ray emission spectroscopy (PIXE) is now routinely used in the field of cultural heritage. Various setups have been developed to investigate the elemental composition of wood/canvas paintings or of cross-section samples. However, it is not possible to obtain information concerning the quantity of organic binder. Backscattering spectrometry (BS) can be a useful complementary method to overcome this limitation. In the case of paint layers, PIXE brings the elemental composition (major elements to traces) and the BS spectrum can give access to the proportion of pigment and binder. With the use of 3 MeV protons for PIXE and BS simultaneously, it was possible to perform quantitative analysis including C and O for which the non-Rutherford cross sections are intense. Furthermore, with the use of the same conditions for PIXE and BS, the experiment time and the potential damage by the ion beam were reduced. The results obtained with the external beam of the Accélérateur Grand Louvre pour l'Analyse Elementaire (AGLAE) facility on various test painting samples and on cross sections from Italian Renaissance masterpieces are shown. Simultaneous combination of PIXE and BS leads to a complete characterization of the paint layers: elemental composition and proportion of the organic binder have been determined and thus provide useful information about ancient oil painting recipes.

  18. Implications of the radio and X-ray emission that followed GW170817

    Science.gov (United States)

    Nakar, Ehud; Piran, Tsvi

    2018-04-01

    The radio and X-rays that followed GW170817 increased gradually over ˜ 100 days, resembling the radio flare predicted to arise from the interaction of a binary neutron star merger outflow with the ISM (Nakar & Piran 2011). Considering a blast wave moving with a Lorentz factor Γ, we show that an off-axis observer, namely an observer at θobs > 1/Γ, sees a light curve rising faster than Fν∝t3. Therefore, the observed rise, Fν∝ t0.78, implies that at all times we have seen an on-axis emission. Namely, the emitting matter was within θobs motivated one, proposed so far, is the interaction of a relativistic jet with the ejecta and the resulting cocoon. The jet could have been choked or successful. In the latter case, it has produced a short GRB pointing elsewhere (this successful jet-cocoon system is sometimes called a "structured jet"). Although circumstantial evidence disfavors a successful jet, the jet fate cannot be decisively determined from current observations. The light curve alone may not be sufficient to resolve this question, since both chocked and successful jets can lead to a gradual rise to a peak, followed by a decay. Therefore, the recent turnover of the light curve does not necessitate a successful jet.

  19. Accretion dynamics and polarized X-ray emission of magnetized neutron stars

    Science.gov (United States)

    Arons, Jonathan

    1991-01-01

    The basic ideas of accretion onto magnetized neutron stars are outlined. These are applied to a simple model of the structure of the plasma mound sitting at the magnetic poles of such a star, in which upward diffusion of photons is balanced by their downward advection. This steady flow model of the plasma's dynamical state is used to compute the emission of polarized X-raysfrom the optically thick, birefringent medium. The linear polarization of the continuum radiation emerging from the quasi-static mound is found to be as much as 40 percent at some rotation phases, but is insensitive to the geometry of the accretion flow. The role of the accretion shock, whose detailed polarimetric and spectral characteristics have yet to be calculated, is emphasized as the final determinant of the properties of the emerging X-rays. Some results describing the fully time dependent dynamics of the flow are also presented. In particular, steady flow onto a neutron star is shown to exhibit formation of 'photon bubbles', regions of greatly reduced plasma density filled with radiation which form and rise on millisecond time scale. The possible role of these complex structures in the flow for the formation of the emergent spectrum is briefly outlined.

  20. X-ray and fast neutron-induced mutations in Arabidopsis thaliana, and the effect of dithiothreitol upon the mutant spectrum

    International Nuclear Information System (INIS)

    Dellaert, L.M.W.

    1980-01-01

    The author discusses the genetic effects of X-ray and fast neutron seed-irradiation of Arabidopsis thaliana (L.) Heynh., and the influence of a pre-irradiation treatment with the radio-protector dithiothreitol (DTT). (Auth.)

  1. The EVE plus RHESSI DEM for Solar Flares, and Implications for Residual Non-Thermal X-Ray Emission

    Science.gov (United States)

    McTiernan, James; Caspi, Amir; Warren, Harry

    2016-05-01

    Solar flare spectra are typically dominated by thermal emission in the soft X-ray energy range. The low energy extent of non-thermal emission can only be loosely quantified using currently available X-ray data. To address this issue, we combine observations from the EUV Variability Experiment (EVE) on-board the Solar Dynamics Observatory (SDO) with X-ray data from the Reuven Ramaty High Energy Spectroscopic Imager (RHESSI) to calculate the Differential Emission Measure (DEM) for solar flares. This improvement over the isothermal approximation helps to resolve the ambiguity in the range where the thermal and non-thermal components may have similar photon fluxes. This "crossover" range can extend up to 30 keV.Previous work (Caspi et.al. 2014ApJ...788L..31C) concentrated on obtaining DEM models that fit both instruments' observations well. For this current project we are interested in breaks and cutoffs in the "residual" non-thermal spectrum; i.e., the RHESSI spectrum that is left over after the DEM has accounted for the bulk of the soft X-ray emission. As in our earlier work, thermal emission is modeled using a DEM that is parametrized as multiple gaussians in temperature. Non-thermal emission is modeled as a photon spectrum obtained using a thin-target emission model ('thin2' from the SolarSoft Xray IDL package). Spectra for both instruments are fit simultaneously in a self-consistent manner.For this study, we have examined the DEM and non-thermal resuidual emission for a sample of relatively large (GOES M class and above) solar flares observed from 2011 to 2014. The results for the DEM and non-thermal parameters found using the combined EVE-RHESSI data are compared with those found using only RHESSI data.

  2. Imaging of high-energy x-ray emission from cryogenic thermonuclear fuel implosions on the NIF.

    Science.gov (United States)

    Ma, T; Izumi, N; Tommasini, R; Bradley, D K; Bell, P; Cerjan, C J; Dixit, S; Döppner, T; Jones, O; Kline, J L; Kyrala, G; Landen, O L; LePape, S; Mackinnon, A J; Park, H-S; Patel, P K; Prasad, R R; Ralph, J; Regan, S P; Smalyuk, V A; Springer, P T; Suter, L; Town, R P J; Weber, S V; Glenzer, S H

    2012-10-01

    Accurately assessing and optimizing the implosion performance of inertial confinement fusion capsules is a crucial step to achieving ignition on the NIF. We have applied differential filtering (matched Ross filter pairs) to provide broadband time-integrated absolute x-ray self-emission images of the imploded core of cryogenic layered implosions. This diagnostic measures the temperature- and density-sensitive bremsstrahlung emission and provides estimates of hot spot mass, mix mass, and pressure.

  3. Imaging of high-energy x-ray emission from cryogenic thermonuclear fuel implosions on the NIF

    Energy Technology Data Exchange (ETDEWEB)

    Ma, T.; Izumi, N.; Tommasini, R.; Bradley, D. K.; Bell, P.; Cerjan, C. J.; Dixit, S.; Doeppner, T.; Jones, O.; Landen, O. L.; LePape, S.; Mackinnon, A. J.; Park, H.-S.; Patel, P. K.; Prasad, R. R.; Ralph, J.; Smalyuk, V. A.; Springer, P. T.; Suter, L.; Town, R. P. J. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); and others

    2012-10-15

    Accurately assessing and optimizing the implosion performance of inertial confinement fusion capsules is a crucial step to achieving ignition on the NIF. We have applied differential filtering (matched Ross filter pairs) to provide broadband time-integrated absolute x-ray self-emission images of the imploded core of cryogenic layered implosions. This diagnostic measures the temperature- and density-sensitive bremsstrahlung emission and provides estimates of hot spot mass, mix mass, and pressure.

  4. X-ray emission from a high-atomic-number z-pinch plasma created from compact wire arrays

    International Nuclear Information System (INIS)

    Sanford, T.W.L.; Nash, T.J.; Marder, B.M.

    1996-03-01

    Thermal and nonthermal x-ray emission from the implosion of compact tungsten wire arrays, driven by 5 MA from the Saturn accelerator, are measured and compared with LLNL Radiation-Hydro-Code (RHC) and SNL Hydro-Code (HC) numerical models. Multiple implosions, due to sequential compressions and expansions of the plasma, are inferred from the measured multiple x-radiation bursts. Timing of the multiple implosions and the thermal x-ray spectra measured between 1 and 10 keV are consistent with the RHC simulations. The magnitude of the nonthermal x-ray emission measured from 10 to 100 keV ranges from 0.02 to 0.08% of the total energy radiated and is correlated with bright-spot emission along the z-axis, as observed in earlier Gamble-11 single exploding-wire experiments. The similarities of the measured nonthermal spectrum and bright-spot emission with those measured at 0.8 MA on Gamble-II suggest a common production mechanism for this process. A model of electron acceleration across magnetic fields in highly-collisional, high-atomic-number plasmas is developed, which shows the existence of a critical electric field, E c , below which strong nonthermal electron creation (and the associated nonthermal x rays) do not occur. HC simulations show that significant nonthermal electrons are not expected in this experiment (as observed) because the calculated electric fields are at least one to two orders-of-magnitude below E c . These negative nonthermal results are confirmed by RHC simulations using a nonthermal model based on a Fokker-Plank analysis. Lastly, the lower production efficiency and the larger, more irregular pinch spots formed in this experiment relative to those measured on Gamble II suggest that implosion geometries are not as efficient as single exploding-wire geometries for warm x-ray production

  5. Spin-polarized x-ray emission of 3d transition-metal ions : A comparison via K alpha and K beta detection

    NARCIS (Netherlands)

    Wang, Xin; deGroot, F.M.F.; Cramer, SP

    1997-01-01

    This paper demonstrates that spin-polarized x-ray-excitation spectra can be obtained using K alpha emission as well as K beta lines. A spin-polarized analysis of K alpha x-ray emission and the excitation spectra by K alpha detection on a Ni compound is reported. A systematic analysis of the

  6. X-ray emission from BL Lac objects: Comparison to the synchrotron self-Compton models

    International Nuclear Information System (INIS)

    Schwartz, D.A.; Madejski, G.; Ku, W.H.-M.

    1982-01-01

    As one part of our joint study of the X-ray properties of BL Lac objects, the authors compare the measured X-ray flux densities with those predicted using the synchrotron self-Compton (SSC) formalism (Jones et al. 1974). Naive application of the formalism predicts X-ray fluxes from 10 -3 to 10 5 those observed. They therefore ask what we can learn by simply assuming the SSC mechanism, and looking for ways to reconcile the observed and measured X-ray fluxes. This paper reports investigation of beaming factors due to relativistic ejection of a radiation source which is isotropic in its own rest frame. The authors conclude that large Lorentz factors, GAMMA approximately > 10, do not apply to BL Lac objects as a class. (Auth.)

  7. Volume effect of laser produced plasma on X-ray emissions

    Indian Academy of Sciences (India)

    A polished copper tip attached to a simple BNC connector was used as Langmuir probes. The probe is kept at a ... 300 ps duration. Two sets of x-ray data taken with 15 J and 11 J constant energy shots clearly shows that two lateral maxima appear in the x-ray signal plotted against the target position relative to the best focus ...

  8. A nanotube-based field emission x-ray source for microcomputed tomography

    International Nuclear Information System (INIS)

    Zhang, J.; Cheng, Y.; Lee, Y.Z.; Gao, B.; Qiu, Q.; Lin, W.L.; Lalush, D.; Lu, J.P.; Zhou, O.

    2005-01-01

    Microcomputed tomography (micro-CT) is a noninvasive imaging tool commonly used to probe the internal structures of small animals for biomedical research and for the inspection of microelectronics. Here we report the development of a micro-CT scanner with a carbon nanotube- (CNT-) based microfocus x-ray source. The performance of the CNT x-ray source and the imaging capability of the micro-CT scanner were characterized

  9. Trace metal analysis in sea grasses from Mexican Caribbean Coast by particle induced X-ray emission (PIXE)

    International Nuclear Information System (INIS)

    Solis, C.; Issac O, K.; Martinez, A.; Lavoisier, E.; Martinez, M. A.

    2008-01-01

    The growing urban and tourist activity in the Mexican Caribbean coasts has resulted in an increase of chemical substances, metals in particular, discharged to the coastal waters. In order to reach an adequate management and conservation of these marine ecosystems it is necessary to perform an inventory of the actual conditions that reflect the vulnerability and the level of damage. Sea-grasses are considered good biological indicators of heavy metal contamination in marine systems. The goal of this preliminary work is to evaluate the concentrations of trace metals such as Cr, Mn, Fe, Co, Cu, Zn, and Pb in Thalassia testudinum, a very common sea-grass in the Mexican Caribbean Sea. Samples were collected from several locations in the coasts of the Yucatan Peninsula: Holbox, Blanquizal and Punta Allen, areas virtually uninfluenced by anthropogenic activities. Trace elements in different part plants were determined by particle induced X-ray emission (PIXE). This is a very suitable technique since it offers a fast, accurate and multi-element analysis. Also, the analysis by PIXE can be performed directly on powdered leaves without a laborious sample preparation. The trace metal concentration determined in sea-grasses growing in Caribbean generally fall in the range of the lowest valuables reported for sea grasses from the Gulf of Mexico. The results indicate that the studied areas do not present contamination by heavy metals. (Author)

  10. PIXE in 1980: Summary of the second international conference on particle induced x-ray emission and its analytical applications

    International Nuclear Information System (INIS)

    Akselsson, K.R.

    1981-01-01

    The Second International Conference on Particle Induced X-ray Emission (PIXE) and its analytical applications was held in Lund, Sweden, June 9-12, 1980. About a hundred papers were presented, including seven invited talks (PIXE and particle scattering, microbeam analysis, applications to aerosols and biological samples). The main impression left by the conference was that both the PIXE method and its applications are in a phase of fast development. Considerable effort has successfully been devoted to optimizing the basic PIXE technique. Also the great advantage of simultaneously getting information about lighter elements and sample mass was reported to have been successfully employed in routine analyses. PIXE, which was initially considered to be a method mainly for thin samples, has also been shown to be competitive for a variety of thick samples. Data from aerosol studies was presented. With the PIXE-method, it is feasible to perform series of measurements over a long period of time, many samples in parallel and/or samples from sites of poor accessibility. However, the advantages of PIXE may be further exploited in aerosol investigations and some promising lines of sampler development were reported. Sample preparation techniques are crucial for applications to biological samples and several laboratories are engaged in such developmental work. However, it was also evident that PIXE is already giving significant contributions to research in biology and medicine

  11. NuSTAR Search for Hard X-ray Emission from the Star Formation Regions in Sh2-104

    Science.gov (United States)

    Gotthelf, Eric V.

    2016-04-01

    We present NuSTAR hard X-ray observations of Sh2-104, a compact Hii region containing several young massive stellar clusters (YMSCs). We have detected distinct hard X-ray sources coincident with localized VERITAS TeV emission recently resolved from the giant gamma-ray complex MGRO J2019+37 in the Cygnus region. Faint, diffuse X-ray emission coincident with the eastern YMSC in Sh2-104 is likely the result of colliding winds of component stars. Just outside the radio shell of Sh2-104 lies 3XMM J201744.7+365045 and nearby nebula NuSTAR J201744.3+364812, whose properties are most consistent with extragalactic objects. The combined XMM-Newton and NuSTAR spectrum of 3XMM J201744.7+365045 is well-fit to an absorbed power-law model with NH = (3.1+/-1.0)E22 1/cm^2 and photon index Gamma = 2.1+/-0.1. Based on possible long-term flux variation and lack of detected pulsations (Sh2-104 will help identify the nature of the X-ray sources and their relation to MGRO J2019+37.

  12. Imaging of High-Energy X-Ray Emission from Cryogenic Thermonuclear Fuel Implosions on the NIF

    International Nuclear Information System (INIS)

    Ma, T.

    2012-01-01

    Accurately assessing and optimizing the implosion performance of inertial confinement fusion capsules is a crucial step to achieving ignition on the NIF. We have applied differential filtering (matched Ross filter pairs) to provide spectrally resolved time-integrated absolute x-ray self-emission images of the imploded core of cryogenic layered targets. Using bremsstrahlung assumptions, the measured absolute x-ray brightness allows for the inference of electron temperature, electron density, hot spot mass, mix mass, and pressure. Current inertial confinement fusion (ICF) experiments conducted on the National Ignition Facility (NIF) seek to indirectly drive a spherical implosion, compressing and igniting a deuterium-tritium fuel. This DT fuel capsule is cryogenically prepared as a solid ice layer surrounded by a low-Z ablator material. Ignition will occur when the hot spot approaches sufficient temperature (∼3-4 keV) and ρR (∼0.3 g/cm 2 ) such that alpha deposition can further heat the hot spot and generate a self-sustaining burn wave. During the implosion, the fuel mass becomes hot enough to emit large amounts of x-ray radiation, the spectra and spatial variation of which contains key information that can be used to evaluate the implosion performance. The Ross filter diagnostic employs differential filtering to provide spectrally resolved, time-integrated, absolute x-ray self-emission images of the imploded core of cryogenic layered targets.

  13. THE RELATION OF OPTICAL/ULTRAVIOLET AND X-RAY EMISSION IN LOW-LUMINOSITY ACTIVE GALACTIC NUCLEI

    International Nuclear Information System (INIS)

    Xu Yadi

    2011-01-01

    We study the relation of optical/UV and X-ray emission in the low luminosity active galactic nuclei (LLAGNs), using a sample of 49 sources including 28 local Seyfert galaxies and 21 low-ionization nuclear emission-line regions with optical/UV spectral luminosity at wavelength λ = 2500 A, 23.0 ≤ log L ν(2500A) (erg s -1 Hz -1 ) ≤ 27.7, and X-ray spectral luminosity at 2 keV, 20.5 ≤ log L ν(2keV) ≤ 25.3. Strong correlations are found between the X-ray luminosity and the optical/UV-to-X-ray index, α ox , with the optical/UV luminosity, with slopes very similar to the findings for the luminous AGNs in previous works. The correlation between α ox and L ν(2keV) is very weak, as is that found for the luminous AGNs in the majority of previous similar works. We also study the relation between α ox and the Eddington ratio L bol /L Edd for our sample and find a significant anti-correlation for the sources with L bol /L Edd ∼ -3 , which is opposite to the correlation between the two variables for the luminous AGNs. Using the advection-dominated accretion flow (ADAF) model, we roughly reproduce this anti-correlationship for the two variables for the LLAGNs. This result strongly supports the ADAF as a candidate for the accretion mode in LLAGNs.

  14. Detailed analysis of hollow ions spectra from dense matter pumped by X-ray emission of relativistic laser plasma

    International Nuclear Information System (INIS)

    Hansen, S. B.; Colgan, J.; Abdallah, J.; Faenov, A. Ya.; Pikuz, S. A.; Skobelev, I. Yu.; Wagenaars, E.; Culfa, O.; Dance, R. J.; Tallents, G. J.; Rossall, A. K.; Woolsey, N. C.; Booth, N.; Lancaster, K. L.; Evans, R. G.; Gray, R. J.; McKenna, P.; Kaempfer, T.; Schulze, K. S.; Uschmann, I.

    2014-01-01

    X-ray emission from hollow ions offers new diagnostic opportunities for dense, strongly coupled plasma. We present extended modeling of the x-ray emission spectrum reported by Colgan et al. [Phys. Rev. Lett. 110, 125001 (2013)] based on two collisional-radiative codes: the hybrid-structure Spectroscopic Collisional-Radiative Atomic Model (SCRAM) and the mixed-unresolved transition arrays (MUTA) ATOMIC model. We show that both accuracy and completeness in the modeled energy level structure are critical for reliable diagnostics, investigate how emission changes with different treatments of ionization potential depression, and discuss two approaches to handling the extensive structure required for hollow-ion models with many multiply excited configurations

  15. CHANDRA CHARACTERIZATION OF X-RAY EMISSION IN THE YOUNG F-STAR BINARY SYSTEM HD 113766

    Energy Technology Data Exchange (ETDEWEB)

    Lisse, C. M. [Planetary Exploration Branch, Space Exploration Sector, Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723 (United States); Christian, D. J. [Department of Physics and Astronomy, California State University Northridge, 18111 Nordhoff Street, Northridge, CA 91330 (United States); Wolk, S. J. [Chandra X-ray Center, Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Günther, H. M. [Massachusetts Institute of Technology, Kavli Institute for Astrophysics and Space Research, 77 Massachusetts Avenue, NE83-569, Cambridge, MA 02139 (United States); Chen, C. H. [STScI, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Grady, C. A., E-mail: carey.lisse@jhuapl.edu, E-mail: damian.christian@csun.edu, E-mail: swolk@cfa.harvard.edu, E-mail: hgunther@mit.edu, E-mail: cchen@stsci.edu, E-mail: carol.a.grady@nasa.gov [Eureka Scientific and Goddard Space Flight Center, Code 667, NASA-GSFC, Greenbelt, MD 20771 (United States)

    2017-02-01

    Using Chandra , we have obtained imaging X-ray spectroscopy of the 10–16 Myr old F-star binary HD 113766. We individually resolve the 1.″4 separation binary components for the first time in the X-ray and find a total 0.3–2.0 keV luminosity of 2.2 × 10{sup 29} erg s{sup −1}, consistent with previous RASS estimates. We find emission from the easternmost, infrared-bright, dusty member HD 113766A to be only ∼10% that of the western, infrared-faint member HD 113766B. There is no evidence for a 3rd late-type stellar or substellar member of HD 113766 with L {sub x} > 6 × 10{sup 25} erg s{sup −1} within 2′ of the binary pair. The ratio of the two stars’ X-ray luminosity is consistent with their assignments as F2V and F6V by Pecaut et al. The emission is soft for both stars, kT {sub Apec} = 0.30–0.50 keV, suggesting X-rays produced by stellar rotation and/or convection in young dynamos, but not accretion or outflow shocks, which we rule out. A possible 2.8 ± 0.15 (2 σ ) hr modulation in the HD 113766B X-ray emission is seen, but at very low confidence and of unknown provenance. Stellar wind drag models corresponding to L {sub x} ∼ 2 × 10{sup 29} erg s{sup −1} argue for a 1 mm dust particle lifetime around HD 113766B of only ∼90,0000 years, suggesting that dust around HD 113766B is quickly removed, whereas 1 mm sized dust around HD 113766A can survive for >1.5 × 10{sup 6} years. At 10{sup 28}–10{sup 29} erg s{sup −1} X-ray luminosity, astrobiologically important effects, like dust warming and X-ray photolytic organic synthesis, are likely for any circumstellar material in the HD 113766 systems.

  16. CHANDRA CHARACTERIZATION OF X-RAY EMISSION IN THE YOUNG F-STAR BINARY SYSTEM HD 113766

    International Nuclear Information System (INIS)

    Lisse, C. M.; Christian, D. J.; Wolk, S. J.; Günther, H. M.; Chen, C. H.; Grady, C. A.

    2017-01-01

    Using Chandra , we have obtained imaging X-ray spectroscopy of the 10–16 Myr old F-star binary HD 113766. We individually resolve the 1.″4 separation binary components for the first time in the X-ray and find a total 0.3–2.0 keV luminosity of 2.2 × 10 29 erg s −1 , consistent with previous RASS estimates. We find emission from the easternmost, infrared-bright, dusty member HD 113766A to be only ∼10% that of the western, infrared-faint member HD 113766B. There is no evidence for a 3rd late-type stellar or substellar member of HD 113766 with L x  > 6 × 10 25 erg s −1 within 2′ of the binary pair. The ratio of the two stars’ X-ray luminosity is consistent with their assignments as F2V and F6V by Pecaut et al. The emission is soft for both stars, kT Apec  = 0.30–0.50 keV, suggesting X-rays produced by stellar rotation and/or convection in young dynamos, but not accretion or outflow shocks, which we rule out. A possible 2.8 ± 0.15 (2 σ ) hr modulation in the HD 113766B X-ray emission is seen, but at very low confidence and of unknown provenance. Stellar wind drag models corresponding to L x  ∼ 2 × 10 29 erg s −1 argue for a 1 mm dust particle lifetime around HD 113766B of only ∼90,0000 years, suggesting that dust around HD 113766B is quickly removed, whereas 1 mm sized dust around HD 113766A can survive for >1.5 × 10 6 years. At 10 28 –10 29 erg s −1 X-ray luminosity, astrobiologically important effects, like dust warming and X-ray photolytic organic synthesis, are likely for any circumstellar material in the HD 113766 systems.

  17. Detailed EXOSAT and optical observations of the intermediate polar 3A0729+103: discovery of two medium energy X-ray emission regions

    International Nuclear Information System (INIS)

    McHardy, I.M.; Pye, J.P.; Fairall, A.P.; Menzies, J.W.

    1987-01-01

    EXOSAT observations of the intermediate polar cataclysmic variable 3A0729+103 reveal a strong orbital modulation, with the 2-4KeV X-rays being significantly more modulated than the 4-6keV X-rays, indicative of photoelectric absorption. The 913 second modulation which is very prominent in the optical light curve, is weakly detected in the medium-energy X-ray light curve, confirming that it represents the white dwarf spin period. These observations are well explained by a combination of two sources of medium-energy X-ray emission. The presence of two emission regions is also clearly seen in the optical spectroscopy, particularly in the intensity of the He II4686 line which has two peaks during the orbit. The authors identify the two optical emission regions with the two X-ray emission regions. (author)

  18. Comparison study of positron emission tomography, X-ray CT and MRI in Parkinsonism with dementia

    International Nuclear Information System (INIS)

    Okada, Junichi; Peppard, R.; Calne, D.B.

    1989-01-01

    Brain atrophy and local cerebral metabolic rate of glucose (LCMR-glc) in Parkinson's disease with dementia and Parkinsonism-dementia complex (PDC) were studied using positron emission tomography (PET) with F-18-2-deoxy-2-fluoro-D-glucose, X-ray CT and magnetic resonance imaging (MRI). The group of Parkinson's disease with dementia (n=7) had a significantly decreased LCMR-glc in all regions when compared with the age-matched normal group. In the group of Parkinson's disease without dementia (n=6), LCMR-glc was also significantly lower than the control group, although it was higher than the group with associated dementia. Some of the normal aged persons had cortical atrophy. There was no correlation between LCMR-glc and cortical atrophy. Six Guamnian patients had PDC associated with amyotrophic lateral sclerosis (ALS), and four patients had it without ALS. LCMR-glc did not differ in the two groups. It was, however, significantly lower than that in 5 Guamanian and 10 Caucasian normal persons. The group of PDC had a noticeable cortical atrophy and ventricular dilatation, regardless of the presence or absence of ALS. There was correlation between decrease of LCMR-glc and cortical atrophy of the frontal, parietal and temporal lobes. Parkinson's disease and PDC were different from Alzheimer's disease in which a decreased LCMR-glc has been reported to be usually confined to the cerebral cortex. Cortical atrophy and ventricular dilatation were depicted on MRI and CT in the PDC group, but did not in the group of Parkinson's disease. PET was useful in the functional examination and both MRI and CT were useful in the anatomical examination of these diseases. (Namekawa, K)

  19. Analysis of memory consolidation and evocation in rats by proton induced X-ray emission

    Energy Technology Data Exchange (ETDEWEB)

    Jobim, P.F.C., E-mail: pjobim@uol.com.br [Ion Implantation Laboratory, Physics Institute, Federal University of Rio Grande do Sul, Av. Bento Gonçalves 9500, CP 15051, CEP 91501-970, Porto Alegre (Brazil); Laboratory of Neuropharmacology and Neural Tumor Biology, Department of Pharmacology, Institute for Basic Health Sciences, Federal University of Rio Grande do Sul, Av. Paulo Gama 90050-170, Porto Alegre (Brazil); University Hospital Research Center (HCPA), Federal University of Rio Grande do Sul, 90035-003, Rua Ramiro Barcelos, Porto Alegre (Brazil); Santos, C.E.I. dos [Ion Implantation Laboratory, Physics Institute, Federal University of Rio Grande do Sul, Av. Bento Gonçalves 9500, CP 15051, CEP 91501-970, Porto Alegre (Brazil); Maurmann, N.; Reolon, G.K. [Laboratory of Neuropharmacology and Neural Tumor Biology, Department of Pharmacology, Institute for Basic Health Sciences, Federal University of Rio Grande do Sul, Av. Paulo Gama 90050-170, Porto Alegre (Brazil); University Hospital Research Center (HCPA), Federal University of Rio Grande do Sul, 90035-003, Rua Ramiro Barcelos, Porto Alegre (Brazil); Debastiani, R. [Ion Implantation Laboratory, Physics Institute, Federal University of Rio Grande do Sul, Av. Bento Gonçalves 9500, CP 15051, CEP 91501-970, Porto Alegre (Brazil); Pedroso, T.R.; Carvalho, L.M. [Laboratory of Neuropharmacology and Neural Tumor Biology, Department of Pharmacology, Institute for Basic Health Sciences, Federal University of Rio Grande do Sul, Av. Paulo Gama 90050-170, Porto Alegre (Brazil); University Hospital Research Center (HCPA), Federal University of Rio Grande do Sul, 90035-003, Rua Ramiro Barcelos, Porto Alegre (Brazil); Dias, J.F. [Ion Implantation Laboratory, Physics Institute, Federal University of Rio Grande do Sul, Av. Bento Gonçalves 9500, CP 15051, CEP 91501-970, Porto Alegre (Brazil)

    2014-08-01

    It is well known that trace elements such as Mg, Ca, Fe, Cu and Zn have a key role in synapse plasticity and learning. Learning process is conventionally divided in three distinct and complementary stages: memory acquisition, consolidation and evocation. Consolidation is the stabilization of the synaptic trace formed by acquisition, while evocation is the recall of this trace. Ion-based techniques capable of providing information concerning the elemental composition of organic tissues may be helpful to improve our understanding on memory consolidation and evocation processes. In particular, the Particle-Induced X-ray Emission (PIXE) technique can be used to analyze different biological tissues with good accuracy. In this work we explore the versatility of PIXE to measure the elemental concentrations in rat brain tissues in order to establish any possible correlation between them and the memory consolidation and evocation processes. To this end, six groups of middle-age male Wistar rats were trained and tested in a step-down Inhibitory Avoidance conditioning. After the behavior tests, the animals were decapitated in accordance with the legal procedures and their brains were removed and dissected for the PIXE analyses. The results demonstrated that there are differences in the elemental concentration among the groups and such variations may be associated with their availability to the learning processes (by memory consolidation and evocation). Moreover, the control groups circumvent the possibility that a non-specific event involved in learning tasks cause such variations. Our results suggest that PIXE may be a useful tool to investigate memory consolidation and evocation in animal models.

  20. Atom-specific look at the surface chemical bond using x-ray emission spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, A.; Wassdahl, N.; Weinelt, M. [Uppsala Univ. (Sweden)] [and others

    1997-04-01

    CO and N{sub 2} adsorbed on the late transition metals have become prototype systems regarding the general understanding of molecular adsorption. It is in general assumed that the bonding of molecules to transition metals can be explained in terms of the interaction of the frontier HOMO and LUMO molecular orbitals with the d-orbitals. In such a picture the other molecular orbitals should remain essentially the same as in the free molecule. For the adsorption of the isoelectronic molecules CO and N{sub 2} this has led to the so called Blyholder model i.e., a synergetic {sigma} (HOMO) donor and {pi} (LUMO) backdonation bond. The authors results at the ALS show that such a picture is oversimplified. The direct observation and identification of the states related to the surface chemical bond is an experimental challenge. For noble and transition metal surfaces, the adsorption induced states overlap with the metal d valence band. Their signature is therefore often obscured by bulk substrate states. This complication has made it difficult for techniques such as photoemission and inverse photoemission to provide reliable information on the energy of chemisorption induced states and has left questions unanswered regarding the validity of the frontier orbitals concept. Here the authors show how x-ray emission spectroscopy (XES), in spite of its inherent bulk sensitivity, can be used to investigate adsorbed molecules. Due to the localization of the core-excited intermediate state, XE spectroscopy allows an atomic specific separation of the valence electronic states. Thus the molecular contributions to the surface measurements make it possible to determine the symmetry of the molecular states, i.e., the separation of {pi} and {sigma} type states. In all the authors can obtain an atomic view of the electronic states involved in the formation of the chemical bond to the surface.