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Sample records for alpha tagged x-ray

  1. Detection of soft X-rays from Alpha Lyrae and Eta Bootis with an imaging X-ray telescope

    Science.gov (United States)

    Topka, K.; Fabricant, D.; Harnden, F. R., Jr.; Gorenstein, P.; Rosner, R.

    1979-01-01

    Results are presented for observations of Alpha Lyr (Vega) and Eta Boo with an imaging X-ray telescope during two rocket flights. It is found that Vega and Eta Boo are soft X-ray sources with respective luminosities of approximately 3 x 10 to the 28th erg/s (0.15-0.8 keV) and 1 x 10 to the 29th erg/s (0.15-1.5 keV). Surface X-ray luminosities of about 640,000 erg/sq cm per sec for Vega and 300,000 erg/sq cm per sec for Eta Boo are estimated and shown to fall within the range of solar coronal X-ray emission. It is concluded that in view of the substantially larger surface areas of these stars, the relatively large total soft X-ray luminosity (as compared with that of the sun) can in both cases be understood as resulting from a moderately active corona, although the Vega observation is in severe conflict with simple models for X-ray emission from single main-sequence stars.

  2. X-ray bumps, iron K-alpha lines, and X-ray suppression by obscuring tori in Seyfert galaxies

    Science.gov (United States)

    Krolik, Julian H.; Madau, Piero; Zycki, Piotr T.

    1994-01-01

    We investigate the X-ray spectral properties of unobscured type 1 and obscured type 2 Seyferts as predicted by the unified Seyfert scheme. We consider the reprocessing of X-ray photons by photoelectric absorption, iron fluorescence, and Compton downscattering in the obscuring tori surrounding these active nuclei, and compute by Monte Carlo methods the reprocessed spectra as a function of the viewing angle. Depending on the optical depth and shape of the torus, and on the viewing angle, the X-ray flux can be suppressed by substantial factors when our line of sight is obscured. We show that an immediate consequence of the existence of an obscuring thick torus is the production in the spectra of type 1 Seyfert galaxies of a bump in the continuum above 10-20 keV and an Fe K-alpha line with significant equivalent width. In those type 2 Seyferts for which the hard X-ray spectrum has been substantially suppressed, the equivalent width of the Fe K-alpha line in the transmitted spectrum can be very large.

  3. Quantitative determination of alpha-quartz in airborne dust samples by x-ray diffraction

    International Nuclear Information System (INIS)

    The quantitative determination by X-ray diffractometry of alpha-quartz In airborne respirable dust samples on silver membrane filters is considered. A cobalt anode X-ray tube Is employed. NiO is used as Internal standard In order to compensate for both the variations of specimen absorption and the effect due to the nonuniformity of the incident X-ray beam and to the incomplete homogeneity on the filters of samples and standards. (Author) 17 refs

  4. K-alpha conversion efficiency measurments for x-ray scattering in inertial confinement fusion plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Kritcher, A L; Neumayer, P; Urry, M K; Robey, H; Niemann, C; Landen, O L; Morse, E; Glenzer, S H

    2006-11-21

    The conversion efficiency of ultra short-pulse laser radiation to K-{alpha} x-rays has been measured for various chlorine-containing targets to be used as x-ray scattering probes of dense plasmas. The spectral and temporal properties of these sources will allow spectrally-resolved x-ray scattering probing with picosecond temporal resolution required for measuring the plasma conditions in inertial confinement fusion experiments. Simulations of x-ray scattering spectra from these plasmas show that fuel capsule density, capsule ablator density, and shock timing information may be inferred.

  5. Characterization of offset printing ink tagged with rare-earth taggants by X-ray emission techniques

    International Nuclear Information System (INIS)

    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 241Am (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)

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

    International Nuclear Information System (INIS)

    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

  7. Target characterization by PIXE, alpha spectrometry and X-ray absorption

    Energy Technology Data Exchange (ETDEWEB)

    Kheswa, N.Y., E-mail: kheswa@tlabs.ac.za [iThemba Laboratory for Accelerator Based Sciences, Old Faure Road, Box 722, Somerset West 7129 (South Africa); Papka, P. [iThemba Laboratory for Accelerator Based Sciences, Old Faure Road, Box 722, Somerset West 7129 (South Africa); Department of Physics, University of Stellenbosch, Private Bag X1, 7602 Matieland (South Africa); Pineda-Vargas, C.A. [iThemba Laboratory for Accelerator Based Sciences, Old Faure Road, Box 722, Somerset West 7129 (South Africa); Faculty of Health and Wellness Sciences, C.P.U.T, Bellville (South Africa); Newman, R.T. [iThemba Laboratory for Accelerator Based Sciences, Old Faure Road, Box 722, Somerset West 7129 (South Africa)

    2011-11-01

    We report on the thickness and homogeneity characterization of thin metallic targets of Zr-96 by means of alpha absorption spectrometry, Particle Induced X-ray Emission (PIXE) and X-ray absorption. The target thicknesses determined by means of the above mentioned methods are critically compared. The thicknesses were determined before and after irradiation with a 70 MeV beam of {sup 14}N ions.

  8. Analytical formulas for calculation of K X-ray production cross sections by alpha ions

    International Nuclear Information System (INIS)

    In the present study, different procedures are followed to deduce the semi-empirical and the empirical K X-rayX-ray production cross sections induced by alpha ions from the available experimental data and the theoretical results of the ECPSSR model for elements with 20≤Z≤30. The deduced K X-ray production cross sections are compared with predictions from ECPSSR model and with other earlier works. Generally, the deduced K X-ray production cross sections obtained by fitting the available experimental data for each element separately give the most reliable values than those obtained by a global fit. - Highlights: ► The results were presented for elements with atomic numbers 20≤Z≤30 by alpha impact. ► The present semi-empirical formulas were derived from both theoretical and experimental values. ► The available experimental data are directly fitted to deduce the empirical one. ► The results obtained for each element separately give the most reliable values than those obtained by a global fit. ► This procedure is proposed as a black-box way to quickly estimate the cross section.

  9. X-ray structure determination of fully hydrated L alpha phase dipalmitoylphosphatidylcholine bilayers.

    OpenAIRE

    Nagle, J F; Zhang, R.; Tristram-Nagle, S; Sun, W.; Petrache, H I; Suter, R M

    1996-01-01

    Bilayer form factors obtained from x-ray scattering data taken with high instrumental resolution are reported for multilamellar vesicles of L alpha phase lipid bilayers of dipalmitoylphosphatidylcholine at 50 degrees C under varying osmotic pressure. Artifacts in the magnitudes of the form factors due to liquid crystalline fluctuations have been eliminated by using modified Caillé theory. The Caillé fluctuation parameter eta 1 increases systematically with increasing lamellar D spacing and th...

  10. Determination of x-ray to alpha ratio and average effective energy required in interpretation of x-ray counting data for internally deposited plutonium

    International Nuclear Information System (INIS)

    For the assessment of plutonium in the lungs, several corrections must be made to X-ray counting data obtained from direct measurement of a person inhaled plutonium aerosol. X/α ratio varying with isotopic composition is one of the important correction factors required in interpretation of the counting data. This paper describes a method of determination of X/α ratio of plutonium, using X-ray - alpha coincidence counter consisted of a proportional counter and a thin NaI-detector, and also describes an empirical method for estimating average effective energy of plutonium which has different isotopic composition. (author)

  11. High-pressure X-ray diffraction study on alpha-PbF2

    OpenAIRE

    Ehm, L.; Knorr, K.; Maedler, F.; Voigtlaender, H.; Busetto, E.; Cassetta, A.; Lausi, A.; Winkler, B.

    2002-01-01

    The high-pressure behaviour of alpha-PbF2 has been investigated by angular-dispersive synchrotron X-ray powder diffraction up to 6.55(8) GPa. The fit of a 3rd-order Birch-Murnaghan equation-of-state gave the volume at zero pressure V0=194.14(4)\\AA$^3 and the bulk modulus b_0=47.0(6)GPa with the pressure derivative b'=7.9(4). The continuous-symmetry-measure approach has been used for the quantification of the distortion of the coordination polyhedron in alpha-PbF2 revealing an increasing disto...

  12. Tensile behavior of orthorhombic alpha ''-titanium alloy studied by in situ X-ray diffraction

    DEFF Research Database (Denmark)

    Wang, X.D.; Lou, H.B.; Ståhl, Kenny;

    2010-01-01

    The tensile behavior of a Ti-11%Zr-14%Nb-10%Sn alloy with pure orthorhombic alpha '' phase was studied by in situ X-ray diffraction using synchrotron radiation. It is found that no phase transformation happens during the whole tensile process. The "double-yielding" platforms of this alloy are ind......, and b and c elongated, and the formation of texture. The similar texture can also be produced upon cold rolling by which the yield strength of the alpha '' phase is largely improved to be over 900 MPa....

  13. X-ray resonant photoexcitation: line widths and energies of K{\\alpha} transitions in highly charged Fe ions

    CERN Document Server

    Rudolph, J K; Epp, S W; Steinbrügge, R; Beilmann, C; Brown, G V; Eberle, S; Graf, A; Harman, Z; Hell, N; Leutenegger, M; Müller, A; Schlage, K; Wille, H -C; Yavas, H; Ullrich, J; López-Urrutia, J R Crespo

    2013-01-01

    Photoabsorption by and fluorescence of the K{\\alpha} transitions in highly charged iron ions are essential mechanisms for X-ray radiation transfer in astrophysical environments. We study photoabsorption due to the main K{\\alpha} transitions in highly charged iron ions from heliumlike to fluorinelike (Fe 24+...17+) using monochromatic X-rays around 6.6 keV at the PETRA III synchrotron photon source. Natural linewidths were determined with hitherto unattained accuracy. The observed transitions are of particular interest for the understanding of photoexcited plasmas found in X-ray binaries and active galactic nuclei.

  14. Mapping alpha-Particle X-Ray Fluorescence Spectrometer (Map-X)

    Science.gov (United States)

    Blake, D. F.; Sarrazin, P.; Bristow, T.

    2014-01-01

    Many planetary surface processes (like physical and chemical weathering, water activity, diagenesis, low-temperature or impact metamorphism, and biogenic activity) leave traces of their actions as features in the size range 10s to 100s of micron. The Mapping alpha-particle X-ray Spectrometer ("Map-X") is intended to provide chemical imaging at 2 orders of magnitude higher spatial resolution than previously flown instruments, yielding elemental chemistry at or below the scale length where many relict physical, chemical, and biological features can be imaged and interpreted in ancient rocks.

  15. Chemistry of Rocks and Soils in Gusev Crater from the Alpha Particle X-ray Spectrometer

    Science.gov (United States)

    Gellert, R.; Rieder, R.; Anderson, R. C.; Brueckner, J.; Clark, B. C.; Dreibus, G.; Economou, T.; Klingelhoefer, G.; Lugmair, G. W.; Ming, D. W.

    2005-01-01

    The alpha particle x-ray spectrometer on the Spirit rover determined major and minor elements of soils and rocks in Gusev crater in order to unravel the crustal evolution of planet Mars. The composition of soils is similar to those at previous landing sites, as a result of global mixing and distribution by dust storms. Rocks (fresh surfaces exposed by the rock abrasion tool) resemble volcanic rocks of primitive basaltic composition with low intrinsic potassium contents. High abundance of bromine (up to 170 parts per million) in rocks may indicate the alteration of surfaces formed during a past period of aqueous activity in Gusev crater.

  16. Joint H-alpha and X-Ray Observations of Massive X-Ray Binaries. II. The Be X-ray Binary and Microquasar LS I +61 303

    OpenAIRE

    Grundstrom, E. D.; Caballero-Nieves, S. M.; Gies, D. R.; Huang, W.; McSwain, M. V.; Rafter, S. E.; Riddle, R. L.; Williams, S. J.; Wingert, D. W.

    2006-01-01

    We present the results of an H-alpha monitoring campaign on the BeXRB and microquasar system LS I +61 303. We use radial velocity measurements of HeI lines in our spectra to re-evaluate the orbital elements and to better establish the time of periastron. We list equivalent widths and other parameters for the H-alpha emission line and discuss the orbital phase related variations observed. We call attention to a dramatic episode of emission weakening that occurred in less than a day that probab...

  17. Yields of Gamma- and X-Ray Radiation of Alpha-Decays of 235U

    International Nuclear Information System (INIS)

    Precise knowledge of gamma- and X-rays emission probabilities of uranium isotopes is vital for accurate gamma-spectrometric determination of the isotopic composition and quantity of uranium. The peak intensity ratio methods employing high resolution gammaspectrometry and intrinsic efficiency calibration approach are known to provide most accurate and reliable isotopic information. When applied to unshielded and moderately shielded material, these methods largely benefit from de-convolution of the 90-100 keV narrow spectral interval, which contains intense gamma- and X-ray lines of major uranium isotopes 235U and 238U. These are the 92.37 keV and 92.79 keV gamma-rays of 238U/234Th, and the 93.35 keV ThKα1 X-rays from alpha-decay of 235U. Although the emission probability ratios of these lines were accurately established, their absolute yields are still lacking accuracy. For instance, as resulted from recent study, the yields of 234Th lines become corrected by 30%, compared with their previous values. This consequently raised a question regarding validity of the yield data for the 93.35 keV line of 235U and triggered the present experimental study. This study was later extended to the reexamination of emission probabilities of other 235U gamma-lines with energies above 205 keV. The experimental data used in the current work was collected using SRM 969 and CRM 146 reference uranium samples. (author)

  18. The Alpha Particle X-Ray Spectrometer (APXS): Results from Gusev Crater and Calibration Report

    Science.gov (United States)

    Gellert, R.; Rieder, R.; Brueckner, J.; Clark, B.; Dreibus, G.; Klingelhoefer, G.; Lugmair, G.; Ming, D.; Waenke, H.; Yen, A.; Zipfel, J.; Squyres, S.

    2006-01-01

    The chemical composition of rocks and soils on Mars analyzed during the Mars Exploration Rover Spirit Mission was determined by X-ray analyses with the Alpha Particle X-Ray Spectrometer (APXS). Details of the data analysis method and the instrument calibration are presented. Measurements performed on Mars to address geometry effects and background contributions are shown. Cross calibration measurements among several instrument sensors and sources are discussed. An unintentional swap of the two flight instruments is evaluated. New concentration data acquired during the first 470 sols of rover Spirit in Gusev Crater are presented. There are two geological regions, the Gusev plains and the Columbia Hills. The plains contain soils that are very similar to previous landing sites on Mars. A meteoritic component in the soil is identified. Rocks in the plains revealed thin weathering rinds. The underlying abraded rock was classified as primitive basalt. One of these rocks contained significant Br that is probably associated with vein-filling material of different composition. One of the trenches showed large subsurface enrichments of Mg, S, and Br. Disturbed soils and rocks in the Columbia Hills revealed different elemental compositions. These rocks are significantly weathered and enriched in mobile elements, such as P, S, Cl, or Br. Even abraded rock surfaces have high Br concentrations. Thus, in contrast to the rocks and soils in the Gusev Plains, the Columbia Hills material shows more significant evidence of ancient aqueous alteration.

  19. Silicon PIN diode for detection of electrons, alphas, X-rays and gamma rays

    International Nuclear Information System (INIS)

    It is well known that Si-PIN diodes can be efficiently used to detect alpha particles and low energy X-rays and gamma rays. The detection efficiency of a Si-PIN diode is a function of the thickness of the silicon wafer. For a wafer thickness of 300 microns, the efficiency for detecting gamma rays beyond 10 keV decreases drastically with energy. PIN diodes have an intrinsic capacitance which reduces with increasing reverse voltage to reach the maximum depletion zone to give best detection efficiency. However, increase in reverse bias voltage introduces higher leakage current. This dark leakage current is strongly temperature dependent due to thermal excitation. Dark current approximately doubles for every 10 °C increase in temperature. The dark current can be dramatically reduced by cooling

  20. Can a variable alpha induce limit cycle behavior and exponential luminosity decay in transient soft x ray sources?

    Science.gov (United States)

    Meirellesfilho, C.; Liang, Edison P.

    1994-01-01

    There has been, recently, a revival of the stability problem of accretion disks. Much of this renewed interest is due to recent observational data on transient soft X-ray novae, which are low-mass X-ray binaries. It is widely believed that nonsteady mass transfer from the secondary onto the compact primary, through an accretion disk, is the reason for the observed spectacular events in the form of often repetitive outbursts, with recurrence times ranging from 1 to 60 yr and duration time on the scale of months. Though not having reached yet a consensus about the nature of the mechanism that regulates the mass transfer, the disk thermal instability model seems to be favored by the fact that the rise in the hard X-ray luminosity is prior to the rise in the soft X-ray luminosity, while the mass transfer instability model seems to be hindered by the fact that the luminosity during quiescence is unable to trigger the thermal instability. However, it should be stressed that, remarkably, the X-ray light curves of these X-ray novae all show overall exponential decays, a feature quite difficult to reproduce in the framework of the viscous disk model, which yields powerlike luminosity decay. Taking into account this observational constraint, we have studied the temporal evolution of perturbations in the accretion rate, under the assumption that alpha is radial and parameter dependent. The chosen dependence is such that the model can reproduce limit cycle behavior (the system is locally unstable but globally stable). However, the kind of dependence we are looking for in alpha does not allow us to use the usual Shakura and Sunyaev procedure in the sense that we no longer can obtain a linearized continuity equation without explicit dependence on the accretion rate. This is so because now we cannot eliminate the accretion rate by using the angular momentum conservation equation.

  1. Comparative cytotoxicity, mutagenicity, and transforming potency of X-rays, alpha particles and MNNG for rat tracheal epithelial cells

    International Nuclear Information System (INIS)

    To characterize the potential roles of high- and low-LET radiation in respiratory carcino-genesis, the biological effects of X rays and alpha particles on rat tracheal epithelial (RTE) cells were determined and compared to the effects of the direct-acting carcinogen, N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Each agent caused logarithmic, dose-dependent killing of RTE cells, although the curve for X rays had a significant shoulder. At equitoxic doses, all three agents induced similar frequencies of preneoplastic transformation. Similarly, each agent was capable of inducing a similar level of mutations in RTE cell lines. These data suggest that both high- and low-LET radiation can induce changes involved in early stages of carcinogenesis. In addition, it suggests that inactivation of critical genes, caused by alpha particle-induced deletions, may play a role in the preneoplastic transformation of RTE cells. (author)

  2. Joint H-alpha and X-ray Observations of Massive X-ray Binaries. I. The B-Supergiant System LS I +65 010 = 2S 0114+650

    CERN Document Server

    Grundstrom, E D; Gies, D R; Huang, W; McSwain, M V; Raghavan, D; Riddle, R L; Subasavage, J P; Wingert, D W; Levine, A M; Remillard, R A

    2006-01-01

    We report on a three year spectroscopic monitoring program of the H-alpha emission in the massive X-ray binary LS I +65 010 = 2S 0114+650, which consists of a B-supergiant and a slowly rotating X-ray pulsar. We present revised orbital elements that yield a period of P=11.5983 +/- 0.0006 d and confirm that the orbit has a non-zero eccentricity e=0.18 +/- 0.05. The H-alpha emission profile is formed in the base of the wind of the B-supergiant primary, and we show how this spectral feature varies on timescales that are probably related to the rotational period of the B-supergiant. We also examine the X-ray fluxes from the Rossi X-ray Timing Explorer All-Sky Monitor instrument, and we show that the X-ray orbital light curve has a maximum at periastron and a minimum at the inferior conjunction of the B-supergiant. We also show that the wind emission strength and the high energy X-ray flux appear to vary in tandem on timescales of approximately a year.

  3. Impact of x-ray dose on the response of CR-39 to 1–5.5 MeV alphas

    Energy Technology Data Exchange (ETDEWEB)

    Rojas-Herrera, J., E-mail: jimmy06@mit.edu; Rinderknecht, H. G.; Zylstra, A. B.; Gatu Johnson, M.; Orozco, D.; Rosenberg, M. J.; Sio, H.; Seguin, F. H.; Frenje, J. A.; Li, C. K.; Petrasso, R. D. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    2015-03-15

    The CR-39 nuclear track detector is used in many nuclear diagnostics fielded at inertial confinement fusion (ICF) facilities. Large x-ray fluences generated by ICF experiments may impact the CR-39 response to incident charged particles. To determine the impact of x-ray exposure on the CR-39 response to alpha particles, a thick-target bremsstrahlung x-ray generator was used to expose CR-39 to various doses of 8 keV Cu-K{sub α} and K{sub β} x-rays. The CR-39 detectors were then exposed to 1–5.5 MeV alphas from an Am-241 source. The regions of the CR-39 exposed to x-rays showed a smaller track diameter than those not exposed to x-rays: for example, a dose of 3.0 ± 0.1 Gy causes a decrease of (19 ± 2)% in the track diameter of a 5.5 MeV alpha particle, while a dose of 60.0 ± 1.3 Gy results in a decrease of (45 ± 5)% in the track diameter. The reduced track diameters were found to be predominantly caused by a comparable reduction in the bulk etch rate of the CR-39 with x-ray dose. A residual effect depending on alpha particle energy is characterized using an empirical formula.

  4. Impact of x-ray dose on the response of CR-39 to 1-5.5 MeV alphas.

    Science.gov (United States)

    Rojas-Herrera, J; Rinderknecht, H G; Zylstra, A B; Gatu Johnson, M; Orozco, D; Rosenberg, M J; Sio, H; Seguin, F H; Frenje, J A; Li, C K; Petrasso, R D

    2015-03-01

    The CR-39 nuclear track detector is used in many nuclear diagnostics fielded at inertial confinement fusion (ICF) facilities. Large x-ray fluences generated by ICF experiments may impact the CR-39 response to incident charged particles. To determine the impact of x-ray exposure on the CR-39 response to alpha particles, a thick-target bremsstrahlung x-ray generator was used to expose CR-39 to various doses of 8 keV Cu-Kα and Kβ x-rays. The CR-39 detectors were then exposed to 1-5.5 MeV alphas from an Am-241 source. The regions of the CR-39 exposed to x-rays showed a smaller track diameter than those not exposed to x-rays: for example, a dose of 3.0 ± 0.1 Gy causes a decrease of (19 ± 2)% in the track diameter of a 5.5 MeV alpha particle, while a dose of 60.0 ± 1.3 Gy results in a decrease of (45 ± 5)% in the track diameter. The reduced track diameters were found to be predominantly caused by a comparable reduction in the bulk etch rate of the CR-39 with x-ray dose. A residual effect depending on alpha particle energy is characterized using an empirical formula. PMID:25832223

  5. Impact of x-ray dose on the response of CR-39 to 1-5.5 MeV alphas

    International Nuclear Information System (INIS)

    The CR-39 nuclear track detector is used in many nuclear diagnostics fielded at inertial confinement fusion (ICF) facilities. Large x-ray uences generated by ICF experiments may impact the CR-39 response to incident charged particles. To determine the impact of x-ray exposure on the CR-39 response to alpha particles, a thick-target bremsstrahlung x-ray generator was used to expose CR-39 to various doses of 8 keV Cu-Kα and Kβ x-rays. The CR-39 detectors were then exposed to 1-5.5 MeV alphas from an Am-241 source. The regions of the CR-39 exposed to x-rays showed a smaller track diameter than those not exposed to x-rays: for example, a dose of 3.0 ± 0.1 Gy causes a decrease of (19 ± 2)% in the track diameter of a 5.5 MeV alpha particle, while a dose of 60.0 ± 1.3 Gy results in a decrease of (45 ± 5)% in the track diameter. The reduced track diameters were found to be predominantly caused by a comparable reduction in the bulk etch rate of the CR-39 with x-ray dose. A residual effect depending on alpha particle energy is characterized using an empirical formula

  6. Analysis of ancient Egyptian finds of metal artefacts by alpha-induced x-ray emission

    International Nuclear Information System (INIS)

    The application of the particle-induced X-ray fluorescence method for the determination of the quantitative composition of objects is described. This is a non-destructive method of analysis, is accurate and highly sensitive. The method is particularly attractive for the examination of valuable archeological finds. The results of the analyses of various Egyptian metal artefacts carried out with the method are presented and discussed

  7. SMM observations of K-alpha radiation from fluorescence of photospheric iron by solar flare X-rays

    Science.gov (United States)

    Parmar, A. N.; Culhane, J. L.; Rapley, C. G.; Wolfson, C. J.; Acton, L. W.; Phillips, K. J. H.; Dennis, B. R.

    1984-01-01

    High-resolution Fe K-alpha spectra near 1.94 A observed during solar flares with the Bent Crystal Spectrometer on the Solar Maximum Mission are presented. The evidence for two possible excitation mechanisms, electron impact and fluorescence, is examined. It is found that the fluorescence mechanism satisfactorily describes the results, while the observations do not support electron collisional excitation of the Fe K-alpha transitions in low ionization stages (II-XII) of iron. Using Bai's model of the fluorescent excitation process, the photospheric iron abundance relative to that of hydrogen is estimated to be 5-6 x 10 to the -5th. The mean height of the soft X-ray source producing the K-alpha fluorescence is calculated on the basis of this model for about 40 large flares. The solar K-alpha lines are found to be about 25 percent wider than those measured in the laboratory. Weak line features observed at wavelengths shorter than that of the K-alpha lines are discussed.

  8. K(alpha) X-ray Emission Spectra from Highly Charged Fe Ions in EBIT

    International Nuclear Information System (INIS)

    A detailed spectral model has been developed for the computer simulation of the 2p → 1s Kα X-ray emission from highly charged Fe ions in the Electron Beam Ion Trap (EBIT). The spectral features of interest occur in the range from 1.84 (angstrom) to 1.94 (angstrom). The fundamental radiative emission processes associated with radiationless electron capture or dielectronic recombination, inner-shell electron collisional excitation, and inner-shell electron collisional ionization are taken in account. For comparison, spectral observations and simulations for high-temperature magnetic-fusion (Tokamak) plasmas are reviewed. In these plasmas, small departures from steady-state corona-model charge-state distributions can occur due to ion transport processes, while the assumption of equilibrium (Maxwellian) electron energy distributions is expected to be valid. Our investigations for EBIT have been directed at the identification of spectral features that can serve as diagnostics of extreme non-equilibrium or transient-ionization conditions, and allowance has been made for general (non-Maxwellian) electron energy distributions. For the precise interpretation of the high-resolution X-ray observations, which may involve the analysis of blended spectral features composed of many lines, it has been necessary to take into account the multitude of individual fine-structure components of the Kα radiative transitions in the ions from Fe XVIII to Fe XXV. At electron densities higher than the validity range of the corona-model approximation, collisionally induced transitions among low-lying excited states can play an important role. It is found that inner-shell electron excitation and ionization processes involving the complex intermediate ions from Fe XVIII to Fe XXI produce spectral features, in the wavelength range from 1.89 (angstrom) to 1.94 (angstrom), which are particularly sensitive to density variations and transient ionization conditions.

  9. An X-ray diffraction procedure for the estimation of the alpha and beta polymorph proportion in sintered silicon carbide

    International Nuclear Information System (INIS)

    The use of X-ray powder diffraction for the determination of the proportions of the alpha and beta polymorphs in the sintered silicon carbide of furnace elements has been investigated. There are several α-SiC reflections without β-SiC counterparts but no unique β-SiC reflection. An internal ratio method cannot therefore be employed and direct reliance must be placed on the intensity change of distinctive α-SiC peaks with progressive β-SiC dilution. Uniformity of sample preparation, sample presentation and machine operating conditions during calibration and subsequent application is therefore essential. The 0.266 nm α-SiC peak was selected for use in calibration as it is readily discriminated above a relatively flat background even at low levels of α-SiC in mixtures of the two polymorphs. (author)

  10. A giant Ly$\\alpha$ nebula in the core of an X-ray cluster at $z=1.99$: implications for early energy injection

    CERN Document Server

    Valentino, F; Finoguenov, A; Strazzullo, V; Brun, A M C Le; Vignali, C; Bournaud, F; Dickinson, M; Renzini, A; Béthermin, M; Zanella, A; Gobat, R; Cimatti, A; Elbaz, D; Onodera, M; Pannella, M; Sargent, M T; Arimoto, N; Carollo, M; Starck, J-L

    2016-01-01

    We present the discovery of a giant $\\gtrsim$100 kpc Ly$\\alpha$ nebula detected in the core of the X-ray emitting cluster CL J1449+0856 at $z=1.99$ through Keck/LRIS narrow-band imaging. This detection extends the known relation between Ly$\\alpha$ nebulae and overdense regions of the Universe to the dense core of a $5-7\\times10^{13}$ M$_{\\odot}$ cluster. The most plausible candidates to power the nebula are two Chandra-detected AGN host cluster members. Given the physical conditions of the Ly$\\alpha$-emitting gas and the possible interplay with the X-ray phase, we argue that the Ly$\\alpha$ nebula would be short-lived ($\\lesssim10$ Myr) if not continuously replenished with cold gas at a rate of $\\gtrsim1000$ Myr. Cooling from the X-ray phase is disfavored as the replenishing mechanism, primarily because of the high Ly$\\alpha$ to X-ray luminosity ratio ($L_{\\mathrm{Ly\\alpha}}/L_{\\mathrm{X}} \\approx0.3$), $\\gtrsim10-1000\\times$ higher than in local cool-core clusters. Cosmological cold flows are disfavored by cu...

  11. New X-ray observations of IQ Aurigae and alpha2 Canum Venaticorum - Probing the magnetically channelled wind shock model in A0p stars

    CERN Document Server

    Robrade, J

    2011-01-01

    We present new X-ray observations of the A0p stars alpha^2 CVn (log Lx < 26.0 erg/s) and IQ Aur (log Lx = 29.6 erg/s) and find that their X-ray luminosities differ by at least three orders of magnitude. IQ Aur possesses a strong cool plasma component with X-ray emitting regions located well above the stellar surface, but also significant amounts of hot plasma. Further, a large X-ray flare is detected from IQ Aur, implying the presence of magnetic reconnection. Our comparison study of similar stars indicates that the occurrence of X-ray emission generated by magnetically channelled wind shocks (MCWS) strongly depends on stellar properties. X-ray emission is preferably generated by more luminous and massive objects such as IQ Aur. The MCWS scenario can consistently describe the X-ray emission of these A0p stars, assuming that the very strong magnetic confinement of the stellar wind has led to the build up of a rigidly rotating disk around the star, where magnetic reconnection and centrifugal breakout events ...

  12. Characterisation of NEXT-DEMO using xenon K$_{\\alpha}$ X-rays

    CERN Document Server

    Lorca, D; Laing, A; Ferrario, P; Gómez-Cadenas, J J; Álvarez, V; Borges, F I G; Camargo, M; Cárcel, S; Cebrián, S; Cervera, A; Conde, C A N; Dafni, T; Díaz, J; Esteve, R; Fernandes, L M P; Ferreira, A L; Freitas, E D C; Gehman, V M; Goldschmidt, A; Gómez, H; González-Díaz, D; Gutiérrez, R M; Hauptman, J; Morata, J A Hernando; Herrera, D C; Irastorza, I G; Labarga, L; Liubarsky, I; Losada, M; Luzón, G; Marí, A; Martínez-Lema, G; Martínez, A; Miller, T; Monrabal, F; Monserrate, M; Monteiro, C M B; Mora, F J; Moutinho, L M; Vidal, J Muñoz; Nebot-Guinot, M; Nygren, D; Oliveira, C A B; Pérez, J; Aparicio, J L Pérez; Renner, J; Ripoll, L; Rodríguez, A; Rodríguez, J; Santos, F P; Santos, J M F dos; Seguí, L; Serra, L; Shuman, D; Simón, A; Sofka, C; Sorel, M; Toledo, J F; Torrent, J; Tsamalaidze, Z; Veloso, J F C A; Webb, R; White, J T; Yahlali, N

    2014-01-01

    The NEXT experiment aims to observe the neutrinoless double beta decay of $^{136}$Xe in a high pressure gas TPC using electroluminescence (EL) to amplify the signal from ionization. Understanding the response of the detector is imperative in achieving a consistent and well understood energy measurement. The abundance of xenon k-shell x-ray emission during data taking has been identified as a multitool for the characterisation of the fundamental parameters of the gas as well as the equalisation of the response of the detector. The NEXT-DEMO prototype is a ~1.5 kg volume TPC filled with natural xenon. It employs an array of 19 PMTs as an energy plane and of 256 SiPMs as a tracking plane with the TPC light tube and SiPM surfaces being coated with tetraphenyl butadiene (TPB) which acts as a wavelength shifter for the VUV scintillation light produced by xenon. This paper presents the measurement of the properties of the drift of electrons in the TPC, the effects of the EL production region, and the extraction of p...

  13. Disc instability models for X-ray transients evidence for evaporation and low $\\alpha$-viscosity?

    CERN Document Server

    Menou, K; Lasota, J P; Narayan, R; Menou, Kristen; Hameury, Jean-Marie; Lasota, Jean-Pierre; Narayan, Ramesh

    2000-01-01

    We construct time-dependent models of accretion discs around black holes and neutron stars. We investigate the effect of evaporating the disc inner regions during quiescence on the predictions of the Disc Instability Model (DIM) for these systems. We do not include irradiation of the disc in the models. Removing the inner, most unstable parts of the accretion disc increases the predicted recurrence times. However, DIMs with values of the viscosity parameter alpha_hot ~ 0.1 and alpha_cold ~ 0.02 (typical of applications of the DIM to standard dwarf nova outbursts) fail to reproduce the long recurrence times of SXTs (unless we resort to fine-tuning of the parameters) independent of the evaporation strength. We show that models with evaporation and a smaller value of alpha_cold (~ 0.005) do reproduce the long recurrence times and the accretion rates at the level of the Eddington rate observed in outburst. The large difference between the values of alpha_hot and alpha_cold, if confirmed when disc irradiation is i...

  14. Multiwavelength analysis of the Lyman alpha emitting galaxy Haro 2: relation between the diffuse Lyman alpha and soft X-ray emissions

    CERN Document Server

    Oti-Floranes, H; Jimenez-Bailon, E; Schaerer, D; Hayes, M; Ostlin, G; Atek, H; Kunth, D

    2012-01-01

    In order to use Lyman alpha (Lya) emission as star formation tracer in cosmological studies, we must understand how the resonant scattering affects the escape fraction of the Lya photons. Thus, high spatial resolution multiwavelength studies of nearby Lya emitters, like Haro 2, are highly needed. For that purpose, we have used Chandra X-ray and HST (UV, optical and NIR) images of Haro 2, and STIS and ground-based spectral images along its major and minor axes, to characterize the Lya emission and the properties of the stellar population. The UV, Ha (Halpha) and FIR luminosities of the Haro 2 nuclear starburst are reproduced using evolutionary synthesis models assuming a young stellar population with ages ~3.5-5.0 Myr, affected by differential interstellar extinctions. The observed X-ray emission is attributed to gas heated by the mechanical energy released by the starburst (soft component) and a Ultra-Luminous X-ray source candidate (hard). Both compact and diffuse Lya components are observed. Whereas Lya is ...

  15. Time-resolved X-ray diffraction of the photochromic alpha-styrylpyrylium trifluoromethanesulfonate crystal films reveals ultrafast structural switching.

    Science.gov (United States)

    Hallmann, Jörg; Morgenroth, Wolfgang; Paulmann, Carsten; Davaasambuu, Jav; Kong, Qingyu; Wulff, Michael; Techert, Simone

    2009-10-21

    The ultrafast structural dynamics of the [2+2] photocycloaddition of alpha-styrylpyrylium trifluoromethanesulfonate (TFMS) has been studied in great detail. During the photoreaction, optical and infrared spectroscopy confirms that crystals of alpha-styrylpyrylium change color. Since the reaction is reversible, it has been suggested to be used as an organic holographic storage device. The present photocrystallographic studies (with high spatial resolution) allow for an electron density analysis of the overall reaction kinetics, revealing the mechanism of bond-breaking and bond-formation. It could furthermore be proved how the reaction is influenced by the rearrangement of the surrounding moieties. Picosecond time-resolved X-ray diffraction studies allow for the monitoring the photoreaction in crystalline thin films under experimental conditions where the transformation times are greatly enhanced. These investigations are discussed in the context of the photocrystallographic results. It has been found that alpha-styrylpyrylium TFMS undergoes an ultrafast photoreaction to the dimer product state and back-reaction to the monomer reactant state which is temperature driven. The present experiments indicate that TFMS reacts on time scales which are the fundamental limiting ones of two-quantum systems and therefore has the potential to be used as an ultrafast organic molecular switcher. PMID:19824735

  16. Characterisation of mineralisation of bone and cartilage: X-ray diffraction and Ca and Sr K{sub {alpha}} X-ray fluorescence microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, D.A. [Centre for Nuclear and Radiation Physics, Department of Physics, University of Surrey, Guildford, Surrey, GU2 7XH (United Kingdom)], E-mail: d.a.bradley@surrey.ac.uk; Muthuvelu, P.; Ellis, R.E.; Green, E.M.; Attenburrow, D. [Biomedical Physics Group, School of Physics, University of Exeter, Exeter (United Kingdom); Barrett, R. [ESRF, BP 220, F-38043 Grenoble Cedex (France); Arkill, K.; Colridge, D.B.; Winlove, C.P. [Biomedical Physics Group, School of Physics, University of Exeter, Exeter (United Kingdom)

    2007-10-15

    Bone is a dynamic structure, constantly remodelling in response to changing mechanical and environmental factors. This is particularly evident in the mineral component encrusting the collagenous framework. The mineral is principally in the form of calcium apatite, but calcium can exchange with strontium, both during the cellular processes of mineralisation and resorption and by passive exchange with the deposited crystals. Mineralisation is generally characterized by densitometry, but because of the differences in absorption cross sections of calcium and strontium it can be misleading in studies of composition. In this work we have used X-ray diffraction to identify calcium and strontium apatite and X-ray fluorescence to quantify strontium and calcium distribution. With the beam characteristics available from synchrotron radiation, this has enabled us to obtain microscopic resolution on thin sections of bone and cartilage from the equine metacarpophalangeal joint. Two issues have been investigated; the first is the distribution of mineral in the bone-cartilage interface and within individual trabeculae. In trabecular bone the ratio of strontium to calcium concentration was typically 0.0035 {+-} 0.0020, and higher by a factor of {approx}3 at the periphery than in the centre of a trabeculum (possibly reflecting the more rapid turnover of mineral in the surface layer). In the dense subchondral bone the ratio was similar, approximately doubling in the calcified cartilage. The second objective was to explore the changes in mineralisation associated with development of osteoarthrosis. We analysed lesions showing cartilage thinning and changes in the trabecular organization and density of the underlying bone. At the centre of the lesion the ratio of strontium to calcium was much lower than that in normal tissue, although the calcified cartilage still showed a higher ratio than the underlying bone. In the superficially normal tissue around the lesion the calcified

  17. Numerical Study of K{\\alpha} X-ray Emission from Multi-layered Cold and Compressed Targets Irradiated by Ultrashort Laser Pulses

    CERN Document Server

    Kelardeh, Hamed Koochaki

    2015-01-01

    In this paper the generation of K{\\alpha} X-ray produced by interaction of ultrashort laser pulses with metal targets has been studied numerically. Several targets were assumed to be irradiated by high intensity ultra-short laser pulses for the calculations. Using Maxwell Boltzmann distribution function for hot electron and applying an analytical model, the number of K{\\alpha} photons were calculated as a function of hot electron temperature, target thickness and K-shell ionization cross section. Also, simulation results of K{\\alpha} yield versus target thickness variations from two and three layer metals have been presented. These calculations are useful for optimization of X-ray yield produced by irradiation of metal targets with high intensity laser pulses. We also generalized this model and present simulation results on K{\\alpha} fluorescence measurement produced by fast electron propagation in shock compressed materials.

  18. A Comparitive Assessement of Cytokine Expression in Human-Derived Cell Lines Exposed to Alpha Particles and X-Rays

    Directory of Open Access Journals (Sweden)

    Vinita Chauhan

    2012-01-01

    Full Text Available Alpha- (α- particle radiation exposure has been linked to the development of lung cancer and has been identified as a radiation type likely to be employed in radiological dispersal devices. Currently, there exists a knowledge gap concerning cytokine modulations associated with exposure to α-particles. Bio-plex technology was employed to investigate changes in proinflammatory cytokines in two human-derived cell lines. Cells were irradiated at a dose of 1.5 Gy to either α-particles or X-rays at equivalent dose rates. The two cell lines exhibited a unique pattern of cytokine expression and the response varied with radiation type. Of the 27 cytokines assessed, only vascular endothelin growth factor (VEGF was observed to be modulated in both cell lines solely after α-particle exposure, and the expression of VEGF was shown to be dose responsive. These results suggest that certain proinflammatory cytokines may be involved in the biological effects related to α- particle exposure and the responses are cell type and radiation type specific.

  19. X-ray reflectivity studies of cPLA2alpha-C2 domains adsorbed onto Langmuir monolayers of SOPC

    Science.gov (United States)

    Malkova, Sarka

    X-ray reflectivity is used to study the interaction of the C2 domain of cytosolic phospholipase A2 with a Langmuir monolayer of SOPC supported on a buffered aqueous solution containing Ca2+. The reflectivity is analyzed in terms of the known crystallographic structure of cPLA2alpha-C2 domains and a slab model representing the lipid layer to yield an electron density profile of the lipid layer and bound C2 domains. This new method of analysis determines the angular orientation and penetration depth of the cPLA2alpha-C2 domains bound to the monolayers, information not possible to obtain from the standard slab model analysis of x-ray reflectivity data. In the best fit orientation, the protein bound Ca 2+ ions are placed within 1 A of the lipid phosphate group (with an accuracy of +/-3 A). Hydrophobic residues of the calcium binding loops CBL1 and CBL3 penetrate deepest into the lipid layer, with a 2 A penetration into the tailgroup region. X-ray measurements with and without the C2 domain indicate a loss of water bound to the headgroup upon binding of the C2 domains. Control experiments with a non-calcium buffer and with domain mutants confirm that the cPLA2alpha-C2 binding to the SOPC monolayer is Ca2+ dependent and that the hydrophobic residues in the calcium binding loops are critical for membrane binding. These results indicate that an entropic component (due to water loss) as well as electrostatic and hydrophobic interactions contribute to the binding mechanism. Labeling the protein domain is not required for these studies. The conditions necessary to measure x-ray reflectivity from Langmuir monolayers of unsaturated lipids with negligible x-ray damage are demonstrated.

  20. Cobalt Coordination and Clustering in [alpha]-Co(OH)[subscript 2] Revealed by Synchrotron X-ray Total Scattering

    Energy Technology Data Exchange (ETDEWEB)

    Neilson, James R.; Kurzman, Joshua A.; Seshadri, Ram; Morse, Daniel E. (UCSB)

    2010-09-17

    Structures of layered metal hydroxides are not well described by traditional crystallography. Total scattering from a synthesis-controlled subset of these materials, as described here, reveals that different cobalt coordination polyhedra cluster within each layer on short length scales, offering new insights and approaches for understanding the properties of these and related layered materials. Structures related to that of brucite [Mg(OH){sub 2}] are ubiquitous in the mineral world and offer a variety of useful functions ranging from catalysis and ion-exchange to sequestration and energy transduction, including applications in batteries. However, it has been difficult to resolve the atomic structure of these layered compounds because interlayer disorder disrupts the long-range periodicity necessary for diffraction-based structure determination. For this reason, traditional unit-cell-based descriptions have remained inaccurate. Here we apply, for the first time to such layered hydroxides, synchrotron X-ray total scattering methods - analyzing both the Bragg and diffuse components - to resolve the intralayer structure of three different {alpha}-cobalt hydroxides, revealing the nature and distribution of metal site coordination. The different compounds with incorporated chloride ions have been prepared with kinetic control of hydrolysis to yield different ratios of octahedrally and tetrahedrally coordinated cobalt ions within the layers, as confirmed by total scattering. Real-space analyses indicate local clustering of polyhedra within the layers, manifested in the weighted average of different ordered phases with fixed fractions of tetrahedrally coordinated cobalt sites. These results, hidden from an averaged unit-cell description, reveal new structural characteristics that are essential to understanding the origin of fundamental material properties such as color, anion exchange capacity, and magnetic behavior. Our results also provide further insights into the

  1. The Magnetic Properties of an L Dwarf Derived from Simultaneous Radio, X-ray, and H-alpha Observations

    OpenAIRE

    Berger, E.; Rutledge, R. E.; Reid, I N; Bildsten, L.; Gizis, J. E.; Liebert, J.; martin, E.; Basri, G.; Jayawardhana, R.; Brandeker, A.; Fleming, T.A.; Johns-Krull, C. M.; Giampapa, M. S.; Hawley, S. L.; Schmitt, J.H.M.M.

    2005-01-01

    We present the first simultaneous, multi-wavelength observations of an L dwarf, the L3.5 candidate brown dwarf 2MASS J00361617+1821104, conducted with the Very Large Array, the Chandra X-ray Observatory, and the Kitt Peak 4-m telescope. We detect strongly variable and periodic radio emission (P=3 hr) with a fraction of about 60% circular polarization. No X-ray emission is detected to a limit of L_X/L_{bol}

  2. Comparative analysis of dose rates in bricks determined by neutron activation analysis, alpha counting and X-ray fluorescence analysis for the thermoluminescence fine grain dating method

    Czech Academy of Sciences Publication Activity Database

    Bártová, H.; Kučera, Jan; Musílek, L.; Trojek, T.

    2014-01-01

    Roč. 104, NOV (2014), s. 393-397. ISSN 0969-806X. [1st International Conference on Dosimetry and its Applications (ICDA). Prague, 23.6.2013-28.6.2013] R&D Projects: GA MŠk(XE) LM2011019 Institutional support: RVO:61389005 Keywords : Alpha coutning * neutron activation analysis * X-ray fluorescence * thermoluminescence dating * dose rate Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 1.380, year: 2014

  3. Quantitative determination of alpha-quartz in airborne dust samples by x-ray diffraction; Determinacion cuantitativa de cuarzo-alfa en polvo atmosferico mediante difraccion de rayos X

    Energy Technology Data Exchange (ETDEWEB)

    Bayon, A.; Roca, M.

    1982-07-01

    The quantitative determination by X-ray diffractometry of alpha-quartz In airborne respirable dust samples on silver membrane filters is considered. A cobalt anode X-ray tube Is employed. NiO is used as Internal standard In order to compensate for both the variations of specimen absorption and the effect due to the nonuniformity of the incident X-ray beam and to the incomplete homogeneity on the filters of samples and standards. (Author) 17 refs.

  4. Discovery of a broad O VIII Ly alpha line in the ultra-compact X-ray binary 4U 1543-624

    CERN Document Server

    Madej, O K

    2010-01-01

    We report the discovery of a broad emission feature at ~0.7 keV in the spectra of the ultra-compact X-ray binary 4U 1543-624, obtained with the high-resolution spectrographs of the XMM-Newton and Chandra satellites. We confirm the presence of the feature in the broad band MOS2 spectrum of the source. As suggested before in the literature, the donor star in this source is a CO or ONe white dwarf, which transfers oxygen-rich material to the accretor, conceivably a neutron star. The X-rays reprocessed in this oxygen-rich accretion disc could give a reflection spectrum with O VIII Ly alpha as the most prominent emission line. Apart from the feature at ~0.7 keV we confirm the possible presence of a weak emission feature at ~6.6 keV, which was reported in the literature for this data set. We interpret the feature at ~0.7 keV and ~6.6 keV as O VIII Ly alpha and Fe K alpha emission respectively, caused by X-rays reflected off the accretion disc in the strong gravitational field close to the accretor.

  5. Probing the origin of the iron K_alpha line around stellar and supermassive black holes using X-ray polarimetry

    CERN Document Server

    Marin, Frederic

    2013-01-01

    Asymmetric, broad iron lines are a common feature in the X-ray spectra of both X-ray binaries (XRBs) and type-1 Active Galactic Nuclei (AGN). It was suggested that the distortion of the Fe K_alpha emission results from Doppler and relativistic effects affecting the radiative transfer close to the strong gravitational well of the central compact object: a stellar mass black hole (BH) or neutron star (NS) in the case of XRBs, or a super massive black hole (SMBH) in the case of AGN. However, alternative approaches based on reprocessing and transmission of radiation through surrounding media also attempt to explain the line broadening. So far, spectroscopic and timing analyzes have not yet convinced the whole community to discriminate between the two scenarios. Here we study to which extent X-ray polarimetric measurements of black hole X-ray binaries (BHXRBs) and type-1 AGN could help to identify the possible origin of the line distortion. To do so, we report on recent simulations obtained for the two BH flavors ...

  6. The sensitivity of the alkaline comet assay in detecting DNA lesions induced by X-rays, gamma rays and alpha particles

    International Nuclear Information System (INIS)

    Experiments were designed and performed in order to investigate whether or not the different cellular energy deposition patterns of photon radiation with different energies (29 kV, 220 kV X-rays; Co-60, Cs-137-γ-rays) and alpha-radiation from an Am-241 source differ in DNA damage induction capacity in human cells. For this purpose, the alkaline comet assay (single cell gel electrophoresis) was applied to measure the amount of DNA damage in relation to the dose received. The comet assay data for the parameters o/oo DNA in the tail' and 'tail moment' for human peripheral lymphocytes did not indicate any difference in the initial radiation damage produced by 29 kV X-rays relative to the reference radiations, 220 kV X-rays and the gamma rays, whether for the total mean dose range of 0-3 Gy nor in the low-dose range. In contrast, when the 'tail length' data were analysed saturation of the fitted dose response curve appeared for X-rays at about 1.5 Gy but was not apparent for gamma rays up to 3 Gy. Preliminary data for alpha exposures of HSC45-M2 cells showed a significant increase in DNA damage only at high doses (>2 Gy Am-241), but the damage at 2 Gy exceeded the damage induced at 2 Gy by Cs-137-γ-rays by a factor of 2.5. In contrast, other experiments involving different cell systems and DNA damage indicators such as chromosomal aberrations have detected a significant increase in DNA damage at much lower doses, that is at 0.02 Gy for Am-241 and depicted a higher biological effectiveness. These results indicate that differences in biological effects arise through downstream processing of complex DNA damage. (authors)

  7. Refinement of the Compton-Rayleigh scatter ratio method for use on the Mars Science Laboratory alpha particle X-ray spectrometer: II - Extraction of invisible element content

    Science.gov (United States)

    Perrett, Glynis M.; Campbell, John L.; Gellert, Ralf; King, Penelope L.; Nield, Emily; O'Meara, Joanne M.; Pradler, Irina

    2016-02-01

    The intensity ratio C/R between Compton and Rayleigh scatter peaks of the exciting Pu L X-rays in the alpha particle X-ray spectrometer (APXS) is strongly affected by the presence of very light elements such as oxygen which cannot be detected directly by the APXS. C/R values are determined along with element concentrations by fitting APXS spectra of geochemical reference materials (GRMs) with the GUAPX code. A quantity K is defined as the ratio between the C/R value determined by Monte Carlo simulation based on the measured element concentrations and the fitted C/R value from the spectrum. To ensure optimally accurate K values, the choice of appropriate GRMs is explored in detail, with attention paid to Rb and Sr, whose characteristic Kα X-ray peaks overlap the Pu Lα scatter peaks. The resulting relationship between the ratio K and the overall oxygen fraction is linear. This provides a calibration from which the concentration of additional light invisible constituents (ALICs) such as water may be estimated in unknown rock and conglomerate samples. Several GRMs are used as 'unknowns' in order to evaluate the accuracy of ALIC concentrations derived in this manner.

  8. On the features of bursts of neutrons, hard x-rays and alpha-particles in the pulse vacuum discharge with a virtual cathode and self-organization

    Science.gov (United States)

    Kurilenkov, Yu K.; Tarakanov, V. P.; Gus'kov, S. Yu; Samoylov, I. S.; Ostashev, V. E.

    2015-11-01

    In this paper, we continue the discussion of the experimental results on the yield of DD neutrons and hard x-rays in the nanosecond vacuum discharge (NVD) with a virtual cathode, which was started in the previous article of this issue, and previously (Kurilenkov Y K et al 2006 J. Phys. A: Math. Gen. 39 4375). We have considered here the regimes of very dense interelectrode aerosol ensembles, in which diffusion of even hard x-rays is found. The yield of DD neutrons in these regimes is conditioned not only by the head-on deuteron-deuteron collisions in the potential well of virtual cathode, but also by the channel of “deuteron-deuterium cluster” reaction, which exceeds overall yield of neutrons per a shot by more than an order of magnitude, bringing it up to ∼ 107/(4π). Very bright bursts of hard x-rays are also represented and discussed here. Presumably, their nature may be associated with the appearance in the NVD of some properties of random laser in the x-ray spectrum. Good preceding agreeing of the experiment on the DD fusion in the NVD with its particle-in-cell (PIC) simulations provides a basis to begin consideration of nuclear burning “proton-boron” in the NVD, which will be accompanied by the release of alpha particles only. With this objective in view, there has been started the PIC-simulation of aneutronic burning of p-B11, and its preliminary results are presented.

  9. Comparative analysis of dose rates in bricks determined by neutron activation analysis, alpha counting and X-ray fluorescence analysis for the thermoluminescence fine grain dating method

    International Nuclear Information System (INIS)

    In order to evaluate the age from the equivalent dose and to obtain an optimized and efficient procedure for thermoluminescence (TL) dating, it is necessary to obtain the values of both the internal and the external dose rates from dated samples and from their environment. The measurements described and compared in this paper refer to bricks from historic buildings and a fine-grain dating method. The external doses are therefore negligible, if the samples are taken from a sufficient depth in the wall. However, both the alpha dose rate and the beta and gamma dose rates must be taken into account in the internal dose. The internal dose rate to fine-grain samples is caused by the concentrations of natural radionuclides 238U, 235U, 232Th and members of their decay chains, and by 40K concentrations. Various methods can be used for determining trace concentrations of these natural radionuclides and their contributions to the dose rate. The dose rate fraction from 238U and 232Th can be calculated, e.g., from the alpha count rate, or from the concentrations of 238U and 232Th, measured by neutron activation analysis (NAA). The dose rate fraction from 40K can be calculated from the concentration of potassium measured, e.g., by X-ray fluorescence analysis (XRF) or by NAA. Alpha counting and XRF are relatively simple and are accessible for an ordinary laboratory. NAA can be considered as a more accurate method, but it is more demanding regarding time and costs, since it needs a nuclear reactor as a neutron source. A comparison of these methods allows us to decide whether the time- and cost-saving simpler techniques introduce uncertainty that is still acceptable. - Highlights: • Dose rates from natural U, Th and K in bricks were determined for the purpose of TL dating. • Results from neutron activation analysis, alpha counting and X-ray fluorescence analysis were compared. • Good match was observed for K determination. • Systematically lower dose rates from U and Th

  10. Non-linearity issues and multiple ionization satellites in the PIXE portion of spectra from the Mars alpha particle X-ray spectrometer

    Science.gov (United States)

    Campbell, John L.; Heirwegh, Christopher M.; Ganly, Brianna

    2016-09-01

    Spectra from the laboratory and flight versions of the Curiosity rover's alpha particle X-ray spectrometer were fitted with an in-house version of GUPIX, revealing departures from linear behavior of the energy-channel relationships in the low X-ray energy region where alpha particle PIXE is the dominant excitation mechanism. The apparent energy shifts for the lightest elements present were attributed in part to multiple ionization satellites and in part to issues within the detector and/or the pulse processing chain. No specific issue was identified, but the second of these options was considered to be the more probable. Approximate corrections were derived and then applied within the GUAPX code which is designed specifically for quantitative evaluation of APXS spectra. The quality of fit was significantly improved. The peak areas of the light elements Na, Mg, Al and Si were changed by only a few percent in most spectra. The changes for elements with higher atomic number were generally smaller, with a few exceptions. Overall, the percentage peak area changes are much smaller than the overall uncertainties in derived concentrations, which are largely attributable to the effects of rock heterogeneity. The magnitude of the satellite contributions suggests the need to incorporate these routinely in accelerator-based PIXE using helium beams.

  11. Vitamin E analogue, D-alpha tocopherol succinate, enhances x-ray induced growth delay of human adenocarcinoma cancer cell line

    International Nuclear Information System (INIS)

    The purpose of this study was to assess the effects of d-alpha Tocopherol succinate (alpha-TS) in modifying radiation-induced viability reduction and apoptosis occurrence in the model for normal and cancer cells. Our hypothesis was that alpha-TS enhances the growth-inhibitory effect of x-irradiation in cancer cells and that the effect is more pronounced in these cells than in normal cells. Murine NIH 3T3 Swiss albino embryonic cells and HT29 human Caucasian colon adenocarcinoma cells were used in the experiments. Alpha-TS was added to the cultures 1 h prior to irradiation with doses of 2 or 5Gy of x-ray. After irradiation cells were incubated for 73 h. Trypan blue exclusion viability test and estimation of apoptosis and necrosis were made. Apoptotic and necrotic cells were counted in fluorescence microscope using fluorescence dyes: propidium iodide and Hoechst 33342. For experiments with the dose of 5 Gy at least five series of experiments were performed. At lower doses (up to approximately 25μM/ml) treatment with alpha-TS alone enhanced growth of both cell lines. At higher doses treatment with alpha-TS alone delayed the growth of the cell cultures, accompanied by 20-25% necrosis. At the concentrations higher than 25μM/mL alpha-TS alone caused growth delay of both cell cultures, being much more pronounced for the cancer cell line HT29. At the concentrations of 50 μM/mL, responsible for about 30-60% of growth delay, there was observed a synergy effect for x-rays and alpha-TS for both cell lines. The effect was more pronounced for HT29 cells (DMF=0.48 for HT29 versus DMF=0.73 for NIH 3T3). These results may confirm the views of the literature reports suggesting that use of vitamin E together with radiation could be favorable for colon cancer treatment; however, more experiments using more advanced techniques are needed

  12. L-shell X-ray production cross sections induced by protons and alpha-particles in the 0.7–2.0 MeV/amu range for Ru and Ag

    Energy Technology Data Exchange (ETDEWEB)

    Bertol, A.P.L., E-mail: anapaula.bertol@gmail.com [Instituto de Física, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil); Trincavelli, J. [Facultad de Matemática, Astronomía y Física, Universidad Nacional de Córdoba (Argentina); Instituto Enrique Gaviola, CONICET (Argentina); Hinrichs, R. [Instituto de Geociências, UFRGS, Porto Alegre, RS (Brazil); Vasconcellos, M.A.Z. [Instituto de Física, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil)

    2014-01-01

    The X-ray emissions induced by protons and alpha-particles of the elements Ag and Ru were measured on mono-elemental thin films. L-shell X-ray production cross sections were obtained for the three L-subshells, considering absorption corrections. The Ag X-ray production cross sections agree with experimental data of other authors and with theoretical models, and were used to endorse the quality of the experimental values for Ru, that were not found in the literature.

  13. L-shell X-ray production cross sections induced by protons and alpha-particles in the 0.7-2.0 MeV/amu range for Ru and Ag

    Science.gov (United States)

    Bertol, A. P. L.; Trincavelli, J.; Hinrichs, R.; Vasconcellos, M. A. Z.

    2014-01-01

    The X-ray emissions induced by protons and alpha-particles of the elements Ag and Ru were measured on mono-elemental thin films. L-shell X-ray production cross sections were obtained for the three L-subshells, considering absorption corrections. The Ag X-ray production cross sections agree with experimental data of other authors and with theoretical models, and were used to endorse the quality of the experimental values for Ru, that were not found in the literature.

  14. Joint x-ray

    Science.gov (United States)

    X-ray - joint; Arthrography; Arthrogram ... x-ray technologist will help you position the joint to be x-rayed on the table. Once in place, pictures are taken. The joint may be moved into other positions for more ...

  15. X-Ray, FUV, and UV Observations of alpha Centauri B: Determination of Long-term Magnetic Activity Cycle and Rotation Period

    CERN Document Server

    DeWarf, L E; Guinan, E F

    2010-01-01

    We have been carrying out a study of stellar magnetic activity, dynamos, atmospheric physics, and spectral irradiances from a sample of solar-type G0-5 V stars with different ages. One of the major goals of this program is to study the evolution of the Sun's X-ray through NUV spectral irradiances with age. Of particular interest is the determination of the young Sun's elevated levels of high-energy fluxes because of the critical roles that X-ray through FUV emissions play on the photochemical and photoionization evolution of early, young planetary atmospheres and ionospheres. Motivated by the current exoplanetary search missions that are hunting for earth-size planets in the habitable zones of nearby main-sequence G-M stars, we are expanding our program to cooler, less luminous, but much more numerous main-sequence K-type stars, such as alpha Centauri B. The long life (2-3x longer than our Sun) and slow evolution of K stars provide nearly constant energy sources for possible hosted planets. Presented here are...

  16. Refinement of the Compton–Rayleigh scatter ratio method for use on the Mars Science Laboratory alpha particle X-ray spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, J.L., E-mail: icampbel@uoguelph.ca [Guelph-Waterloo Physics Institute, University of Guelph, Guelph, Ontario, Canada N1G 2W1 (Canada); Perrett, G.M. [Guelph-Waterloo Physics Institute, University of Guelph, Guelph, Ontario, Canada N1G 2W1 (Canada); Maxwell, J.A. [3A 47 Surrey St. East, Guelph, Ontario, Canada N1H 3P6 (Canada); Nield, E.; Gellert, R. [Guelph-Waterloo Physics Institute, University of Guelph, Guelph, Ontario, Canada N1G 2W1 (Canada); King, P.L. [Research School of Earth Sciences, Australian National University, Canberra, ACT 0200 (Australia); Lee, M.; O’Meara, J.M.; Pradler, I. [Guelph-Waterloo Physics Institute, University of Guelph, Guelph, Ontario, Canada N1G 2W1 (Canada)

    2013-05-01

    Spectra from the Mars rover alpha particle X-ray spectrometers contain the elastic and inelastic scatter peaks of the plutonium L X-rays emitted by the instrument’s {sup 244}Cm source. Various spectrum fitting approaches are tested using the terrestrial twin of the APXS instrument on the Mars Science Laboratory Curiosity rover, in order to provide accurate extraction of the Lα and Lβ Compton/Rayleigh intensity ratios, which can provide information about light “invisible” constituents such as water in geological samples. A well-defined dependence of C/R ratios upon mean sample atomic number is established using a large and varied set of geochemical reference materials, and the accuracy of this calibration is examined. Detailed attention is paid to the influence of the rubidium and strontium peaks which overlap the Lα scatter peaks. Our Monte Carlo simulation code for prediction of C/R ratios from element concentrations is updated. The ratio between measured and simulated C/R ratios provides a second means of calibration.

  17. Semiconductor X-ray detectors

    CERN Document Server

    Lowe, Barrie Glyn

    2014-01-01

    Identifying and measuring the elemental x-rays released when materials are examined with particles (electrons, protons, alpha particles, etc.) or photons (x-rays and gamma rays) is still considered to be the primary analytical technique for routine and non-destructive materials analysis. The Lithium Drifted Silicon (Si(Li)) X-Ray Detector, with its good resolution and peak to background, pioneered this type of analysis on electron microscopes, x-ray fluorescence instruments, and radioactive source- and accelerator-based excitation systems. Although rapid progress in Silicon Drift Detectors (SDDs), Charge Coupled Devices (CCDs), and Compound Semiconductor Detectors, including renewed interest in alternative materials such as CdZnTe and diamond, has made the Si(Li) X-Ray Detector nearly obsolete, the device serves as a useful benchmark and still is used in special instances where its large, sensitive depth is essential. Semiconductor X-Ray Detectors focuses on the history and development of Si(Li) X-Ray Detect...

  18. Oscillator strengths and radiative transition rates for K{sub {alpha}} lines in gold X-ray spectra: 1s-2p transitions

    Energy Technology Data Exchange (ETDEWEB)

    Nahar, Sultana N. [Department of Astronomy, Ohio State University, Columbus, OH 43210 (United States)], E-mail: nahar@astronomy.ohio-state.edu; Pradhan, Anil K.; Sur, Chiranjib [Department of Astronomy, Ohio State University, Columbus, OH 43210 (United States)

    2008-07-15

    Oscillator strengths (f), line strengths (S) and radiative decay rates (A) are presented for all 1s-2p transitions in gold (Au) ions. X-ray emission from gold is extensively used, such as in fusion experiments, and in medical research for diagnostics and treatment. The K{sub {alpha}} 1s-2p transitions in gold are found to be in the hard X-ray region of 66-73 keV (0.1888-0.1706A) and are limited to from hydrogen-like to fluorine-like ions as the 2p subshell is filled beyond fluorine. While there are two 1s-2p transitions (1s{sup 2}S{sub 1/2}-2p{sup 2}P{sub 1/2}{sup o} and 1s{sup 2}S{sub 1/2}-2p{sup 2}P{sub 3/2}{sup o}) for hydrogen-like gold, Au{sup +78}, the number varies depending on the number of electrons in the 2p subshell before and after the transition. For example, there are 35 1s-2p transitions giving the same number of K{sub {alpha}} lines for carbon-like Au, Au{sup +73}. The transitions can be of both types, dipole allowed and intercombination, and are in general strong, that is, A{approx}10{sup 16}/s. However, there are also weak transitions in the set. The present results are obtained from configuration interaction atomic structure calculations using the code SUPERSTRUCTURE which includes relativistic effects in Breit-Pauli approximation. The results have been benchmarked for a few ionic states with other detailed relativistic approaches, such as Dirac-Fock and coupled cluster. Comparisons with the very few transitions in the literature as well as those from other approaches indicate reasonable accuracy for the present results.

  19. Chest x-ray

    Science.gov (United States)

    Chest radiography; Serial chest x-ray; X-ray - chest ... You stand in front of the x-ray machine. You will be told to hold your breath when the x-ray is taken. Two images are usually taken. You will ...

  20. The Seyfert 2 Galaxy NGC 2110: Hard X-Ray Emission Observed by NuStar and Variability of the Iron K-Alpha Line

    Science.gov (United States)

    Marinucci, A.; Matt, G.; Bianchi, S.; Lu, T. N.; Arevalo, P.; Balokovic, M.; Ballantyne, D.; Bauer, F. E.; Boggs, S. E.; Stern, D.; Zhang, William W.

    2014-01-01

    We present NuSTAR observations of the bright Seyfert 2 galaxy NGC 2110 obtained in 2012, when the source was at the highest flux level ever observed, and in 2013, when the source was at a more typical flux level. We include archival observations from other X-ray satellites, namely XMM-Newton, Suzaku, BeppoSAX, Chandra and Swift. Simultaneous NuSTAR and Swift broad band spectra (in the 3-80 keV range) indicate a cutoff energy E(sub c) greater than 210 keV, with no detectable contribution from Compton reflection. NGC 2110 is one of the very few sources where no evidence for distant Compton thick scattering is found and, by using temporal information collected over more than a decade, we investigate variations of the iron K(alpha) line on time scales of years. The Fe K alpha line is likely the sum of two components: one constant (originating from distant Compton-thick material) and the other one variable and linearly correlated with the source flux (possibly arising from Compton-thin material much closer to the black hole).

  1. Response of semi-insulating 100{mu}m thick GaAs detector for {alpha}-particles, {gamma}-rays and X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Kordyasz, A.J. [Heavy Ion Laboratory, Warsaw University, ul. Pasteura 5a, 02-093 Warsaw (Poland)]. E-mail: kord@slcj.uw.edu.pl; Strzelecka, S.G. [Institute of Electronic Materials Technology, Warsaw (Poland); Kownacki, J. [Heavy Ion Laboratory, Warsaw University, ul. Pasteura 5a, 02-093 Warsaw (Poland); Dobrzanski, L. [Institute of Electronic Materials Technology, Warsaw (Poland); Hruban, A. [Institute of Electronic Materials Technology, Warsaw (Poland); OrIowski, W. [Institute of Electronic Materials Technology, Warsaw (Poland); Wegner, E. [Institute of Electronic Materials Technology, Warsaw (Poland); Reissig, L. [Center for Inter-Faculty Individual Studies in Mathematical and Natural Sciences, University of Warsaw, Warsaw (Poland)]. E-mail: louisa@slcj.uw.edu.pl

    2005-06-21

    The 100{mu}m thick, transmission, fully depleted GaAs Schottky barrier detector fabricated from LEC bulk GaAs crystals has been tested. The basic structure of the detector consists of a Cr/Au Schottky contact and an Au/Ge/Ni/Au alloyed ohmic contact. Pulse height spectra for {alpha}-particles resulting from irradiation with triple source {sup 239}Pu, {sup 241}Am, {sup 244}Cm, with energies 5.155, 5.486, 5.805MeV were acquired. The energy resolution for these energies was better than 10keV (1.8%). Using {sup 241}Am 5.486MeV {alpha}-particles a charge collection efficiency (CCE) of about 94% was obtained at 570V bias potential. The spectra of low-energy {gamma}-rays 59.5keV and X-rays with average energy 16.2keV from {sup 241}Am source measured at room temperature are presented. An energy resolution of about 6.1keV (10.3%) FWHM at 59.5keV was obtained.

  2. Thoracic spine x-ray

    Science.gov (United States)

    Vertebral radiography; X-ray - spine; Thoracic x-ray; Spine x-ray; Thoracic spine films; Back films ... care provider's office. You will lie on the x-ray table in different positions. If the x-ray ...

  3. Comparative analysis of dose rates in bricks determined by neutron activation analysis, alpha counting and X-ray fluorescence analysis for the thermoluminescence fine grain dating method

    Science.gov (United States)

    Bártová, H.; Kučera, J.; Musílek, L.; Trojek, T.

    2014-11-01

    In order to evaluate the age from the equivalent dose and to obtain an optimized and efficient procedure for thermoluminescence (TL) dating, it is necessary to obtain the values of both the internal and the external dose rates from dated samples and from their environment. The measurements described and compared in this paper refer to bricks from historic buildings and a fine-grain dating method. The external doses are therefore negligible, if the samples are taken from a sufficient depth in the wall. However, both the alpha dose rate and the beta and gamma dose rates must be taken into account in the internal dose. The internal dose rate to fine-grain samples is caused by the concentrations of natural radionuclides 238U, 235U, 232Th and members of their decay chains, and by 40K concentrations. Various methods can be used for determining trace concentrations of these natural radionuclides and their contributions to the dose rate. The dose rate fraction from 238U and 232Th can be calculated, e.g., from the alpha count rate, or from the concentrations of 238U and 232Th, measured by neutron activation analysis (NAA). The dose rate fraction from 40K can be calculated from the concentration of potassium measured, e.g., by X-ray fluorescence analysis (XRF) or by NAA. Alpha counting and XRF are relatively simple and are accessible for an ordinary laboratory. NAA can be considered as a more accurate method, but it is more demanding regarding time and costs, since it needs a nuclear reactor as a neutron source. A comparison of these methods allows us to decide whether the time- and cost-saving simpler techniques introduce uncertainty that is still acceptable.

  4. Chest X-Ray

    Medline Plus

    Full Text Available ... the most commonly performed x-ray exams and use a very small dose of ionizing radiation to ... to your health. While a chest x-ray use a tiny dose of ionizing radiation, the benefit ...

  5. Dental x-rays

    Science.gov (United States)

    X-ray - teeth; Radiograph - dental; Bitewings; Periapical film; Panoramic film ... dentist's office. There are many types of dental x-rays. Some are: Bitewing Periapical Palatal (also called occlusal) ...

  6. X-ray (image)

    Science.gov (United States)

    X-rays are a form of ionizing radiation that can penetrate the body to form an image on ... will be shades of gray depending on density. X-rays can provide information about obstructions, tumors, and other ...

  7. X-ray apparatus

    International Nuclear Information System (INIS)

    A diagnostic x-ray device, readily convertible between conventional radiographic and tomographic operating modes, is described. An improved drive system interconnects and drives the x-ray source and the imaging device through coordinated movements for tomography

  8. Sensitivity of the Fe K-alpha Compton shoulder to the geometry and variability of the X-ray illumination of cosmic objects

    CERN Document Server

    Odaka, Hirokazu; Takahashi, Tadayuki; Fabian, Andrew

    2016-01-01

    In an X-ray reflection spectrum, a tail-like spectral feature generated via Compton down-scattering, known as a Compton shoulder (CS), appears at the low-energy side of the iron K$\\alpha$ line. Despite its great diagnostic potential, its use as a spectral probe of the reflector has been seriously limited due to observational difficulties and modelling complexities. We revisit the basic nature of the CS by systematic investigation into its dependence on spatial and temporal parameters. The calculations are performed by Monte-Carlo simulations for sphere and slab geometries. The dependence is obtained in a two-dimensional space of column density and metal abundance, demonstrating that the CS solves parameter degeneration between them which was seen in conventional spectral analysis using photoelectric absorption and fluorescence lines. Unlike the iron line, the CS does not suffer from any observational dependence on the spectral hardness. The CS profile is highly dependent on the inclination angle of the slab g...

  9. X-ray diffraction analysis of scrapie prion: intermediate and folded structures in a peptide containing two putative alpha-helices.

    Science.gov (United States)

    Inouye, H; Kirschner, D A

    1997-05-01

    Small proteinaceous infectious particles called prions cause certain neurodegenerative diseases in human and animals. Limited proteolysis of infectious scrapie prions PrP(Sc) yields an N-truncated polypeptide termed PrP 27-30, which encompasses residues 90 to 231 of PrP(Sc) and which assembles into 100 to 200 A wide amyloid rods. It has been hypothesized that the infectious prion is converted from its non-infectious cellular form (PrP(C)) by means of an alpha-helical to beta-sheet conformational change. Secondary structure analysis, computer modeling, and structural biophysics methods support this hypothesis. Residues 90 to 145 of PrP, which contain two putative alpha-helical domains H1 and H2, may be of particular relevance to the disease pathogenesis, as C-terminal truncation at residue 145 was found in a patient with an inherited prion disease. Moreover, our recent X-ray diffraction analysis suggests that the peptide consisting of these residues (designated SHa 90-145) closely models the amyloidogenic beta-sheet core of PrP. In the current study, we have analyzed in detail the X-ray diffraction patterns of SHa 90-145. Two samples were examined: one that was dehydrated under ambient conditions whilst in an external magnetic field (to induce fibril orientation), and another that was sealed after partial drying. The dried, magnetically oriented sample showed a cross-beta diffraction pattern in which the fiber axis (rotation axis) was parallel to the H-bonding direction of the beta-sheets. The major wide-angle peaks indicate the presence of approximately 40 A wide beta-crystallites, which constitute the protofilament. Each crystallite is composed of several orthogonal unit cells, normal to the fiber (a-axis) direction, having lattice constants a = 9.69 A, b = 6.54 A, and c = 18.06 A. Electron density maps were calculated by iterative Fourier synthesis using beta-silk as an initial phase model. The distribution of density indicated that there were two types of beta

  10. X-Rays

    Science.gov (United States)

    X-rays are a type of radiation called electromagnetic waves. X-ray imaging creates pictures of the inside of your ... different amounts of radiation. Calcium in bones absorbs x-rays the most, so bones look white. Fat and ...

  11. Chest X-Ray

    Medline Plus

    Full Text Available ... by: Image/Video Gallery Your radiologist explains chest x-ray. Transcript Welcome to Radiology Info dot org! Hello, ... you about chest radiography also known as chest x-rays. Chest x-rays are the most commonly performed ...

  12. X-Ray Imaging

    Science.gov (United States)

    ... Brain Surgery Imaging Clinical Trials Basics Patient Information X-Ray Imaging Print This Page X-ray imaging is perhaps the most familiar type of imaging. Images produced by X-rays are due to the different absorption rates of ...

  13. Crystallization and preliminary X-ray diffraction analysis of the complex between a human anti-alpha toxin antibody fragment and alpha toxin

    International Nuclear Information System (INIS)

    Crystals of the complex between the Fab fragment of a human anti-alpha toxin antibody and alpha toxin have been obtained. Diffraction data sets were collected to 2.56 Å resolution. Staphylococcus aureus alpha toxin (AT) has been crystallized in complex with the Fab fragment of a human antibody (MEDI4893). This constitutes the first reported crystals of AT bound to an antibody. The monoclinic crystals belonged to space group P21, with unit-cell parameters a = 85.52, b = 148.50, c = 93.82 Å, β = 99.82°. The diffraction of the crystals extended to 2.56 Å resolution. The asymmetric unit contained two MEDI4893 Fab–AT complexes. This corresponds to a crystal volume per protein weight (VM) of 2.3 Å3 Da−1 and a solvent content of 47%. The three-dimensional structure of this complex will contribute to an understanding of the molecular basis of the interaction of MEDI4893 with AT. It will also shed light on the mechanism of action of this antibody, the current evaluation of which in the field of S. aureus-mediated diseases makes it a particularly interesting case study. Finally, this study will provide the three-dimensional structure of AT in a monomeric state for the first time

  14. Relation of large-scale coronal X-ray structure and cosmic rays. I - Sources of solar wind streams as defined by X-ray emission and H-alpha absorption features

    Science.gov (United States)

    Krieger, A. S.; Nolte, J. T.; Sullivan, J. D.; Lazarus, A. J.; Mcintosh, P. S.; Gold, R. E.; Roelof, E. C.

    1975-01-01

    The large-scale structure of the corona and the interplanetary medium during Carrington rotations 1601-1607 is discussed relative to recurrent high-speed solar wind streams and their coronal sources. Only streams A, C, D, and F recur on more than one rotation. Streams A and D are associated with coronal holes, while C and F originate in the high corona (20-50 solar radii) over faint X-ray emissions. The association of the streams with holes is confirmed by earlier findings that there are no large equatorial holes without an associated high-speed stream and that the area of the equatorial region of coronal holes is highly correlated with the maximum velocity observed in the associated stream near 1 AU.

  15. Insights from soft X-rays: the chlorine and sulfur sub-structures of a CK2alpha/DRB complex

    OpenAIRE

    Raaf, J.; Issinger, O.-G.; Niefind, K.

    2008-01-01

    The diffraction pattern of a protein crystal is normally a product of the interference of electromagnetic waves scattered by electrons of the crystalline sample. The diffraction pattern undergoes systematic changes in case additionally X-ray absorption occurs, meaning if the wavelength of the primary X-ray beam is relatively close to the absorption edge of selected elements of the sample. The resulting effects are summarized as "anomalous dispersion" and can be always observed with "soft" X-r...

  16. L{sub i} ({alpha}, {beta}, {gamma}, l) subshell X-ray production cross-sections and theirs emission ratio in Pb and Au for proton energy 1-2.5 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Ouziane, S [Faculte de Physique, Universite des Sciences et de Technologie Houari Boumediene, BP 32, El Alia, Bab Ezzouar 16111 Alger (Algeria); Amokrane, A [Faculte de Physique, Universite des Sciences et de Technologie Houari Boumediene, BP 32, El Alia, Bab Ezzouar 16111 Alger (Algeria); Toumert, I [Centre de Recherches Nucleaires d' Alger, 2 Bd Frantz Fanon, BP 399, Alger (Algeria)

    2006-05-15

    The L{sub i} ({alpha}, {beta}, {gamma}, l) subshell X-ray production cross-sections for Pb and Au were measured at incident proton energy between 1 to 2.5 MeV. The obtained data are compared to available data given in Sokhi and Crumpton and Orlic and al. compilations. The given data are also compared with the predictions of ECPSSR model. The comparison shows a good agreement.

  17. X-Ray Polarimetry

    OpenAIRE

    Kaaret, Philip

    2014-01-01

    We review the basic principles of X-ray polarimetry and current detector technologies based on the photoelectric effect, Bragg reflection, and Compton scattering. Recent technological advances in high-spatial-resolution gas-filled X-ray detectors have enabled efficient polarimeters exploiting the photoelectric effect that hold great scientific promise for X-ray polarimetry in the 2-10 keV band. Advances in the fabrication of multilayer optics have made feasible the construction of broad-band ...

  18. Response of X-UV photodiodes to 1.5-17.5 keV x rays and MeV alpha particles

    Science.gov (United States)

    Wenzel, Kevin W.; Li, Chi-Kang; Petrasso, Richard D.; Lo, Daniel H.; Bautz, Marshall W.; Ricker, George R., Jr.; Hsieh, Ed

    1993-07-01

    The absolute x-ray response of three X-UV photodiodes was measured over an energy range of 1.5-17.5 keV so that they could be used to calibrate x-ray imaging systems for the ASCA satellite mission. An intense electron-beam x-ray generator was used to test both the dc and ac x-ray response at 1.5, 4.5, 8.0, and 17.5 keV, and an 55Fe source was used to examine one of the photodiodes at 5.9 keV. The x-ray response was determined by comparing the X-UV diode signal to that of a previously calibrated silicon surface barrier diode (SBD). The X-UV detector response was similar to the SBD response at low energies (1.5 and 4.5 keV). At 8 keV, the X-UV detectors exhibited about 70% of the SBD response, and at 17.5 keV, about 50%. This result is surprising, because the X-UV diodes actually have a greater silicon thickness than the SBD. In contrast to our findings for SBDs in the past, this implies that not the entire physical volume of these detectors comprises the active volume. The X-UV detector x-ray response was also examined as a function of the applied bias voltage. No significant bias voltage dependence of the x-ray signal was found, which indicates that the depletion layer thickness does not determine the active volume either. However, the detector noise was found to decrease substantially as the applied bias was raised from zero to a few volts. Response of these detectors, operated in pulse mode, to 226Ra α particles indicated large charge carrier recombination in the bulk silicon. This feature renders these detectors unsuitable for most charged-particle spectroscopy applications.

  19. X-ray interferometers

    International Nuclear Information System (INIS)

    An improved type of amplitude-division x-ray interferometer is described. The wavelength at which the interferometer can operate is variable, allowing the instrument to be used to measure x-ray wavelength, and the angle of inclination is variable for sample investigation. (U.K.)

  20. X-ray - skeleton

    Science.gov (United States)

    A skeletal x-ray is an imaging test used to look at the bones. It is used to detect fractures , tumors, or ... in the health care provider's office by an x-ray technologist. You will lie on a table or ...

  1. Extremity x-ray

    Science.gov (United States)

    An extremity x-ray is an image of the hands, wrist, feet, ankle, leg, thigh, forearm humerus or upper arm, hip, shoulder ... term "extremity" often refers to a human limb. X-rays are a form of radiation that passes through ...

  2. Dental x-rays

    Science.gov (United States)

    ... addition, many dentists are taking x-rays using digital technology. The image runs through a computer. The amount of radiation given off during the procedure is less than traditional methods. Other types of dental x-rays can create a 3-D picture ...

  3. Millimeter-Scale Chemistry of Observable Endmembers with the Mars Science Laboratory Alpha Particle X-Ray Spectrometer and Mars Hand Lens Imager

    Science.gov (United States)

    VanBommel, Scott; Gellert, Ralf; Thompson, Lucy; Berger, Jeff; Campbell, Iain; Edgett, Ken; McBride, Marie; Minitti, Michelle; Desouza, Elstan; Boyd, Nick

    2016-04-01

    The Alpha Particle X-ray Spectrometer (APXS) is a bulk chemistry instrument conducting high-precision in-situ measurements of Martian rocks and soils onboard both active NASA rovers [1]. Mounted at the end of the Curiosity rover arm, the APXS can conduct multi-spot (raster) investigations in a single morning or evening. Combining APXS raster spectra and Mars Hand Lens Imager (MAHLI) images, a modeled terrain is developed in which the positions of APXS field of views (FOV) can be localized, thereby mitigating arm placement uncertainty. An acquired APXS spectrum is the result of the weighted sum of the signals from within the FOV. The spatial sensitivity of the APXS consists of an off-nadir contribution in addition to a vertical separation (standoff with respect to the APXS detector) contribution [2, 3]. MAHLI images and focus merge (MFM) products facilitate a 3D surface model of the target [4] compensating for the effects of sample relief in an APXS spectrum. Employing a MFM relief map, APXS placement is modeled in three-dimensions, permitting variable APXS docking (standoff, deployment angle). Through minimization, we arrive at millimeter-scale chemistry of veins, diagenetic features and dust-free rock endmembers of Martian targets. Several rasters have been conducted with Curiosity's APXS on Mars including a study of the Garden City outcrop. The area is characterized by its contrasting light and dark veins of cm-scale surface relief. Three-dimensional localization and minimization indicated calcium sulfate as the major component of the light vein while the dark vein is enriched in CaO (without accompanying SO3), MnO, Ni and Zn, with respect to average Mars composition. References: [1] Gellert et al. (2014), LPSC XLV, #1876. [2] VanBommel et al. (2015), LPSC XLVI, #2049. [3] VanBommel et al. (2016), XRS #2681. [4] Edgett et al. (2015), MAHLI Tech Rept 0001. Acknowledgements: The MSL APXS is financed and managed by the Canadian Space Agency (CSA) with Mac

  4. Study of radiation effects on the cell structure and evaluation of the dose delivered by x-ray and {alpha}-particles microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kosior, Ewelina; Cloetens, Peter [European Synchrotron Radiation Facility, F-38000 Grenoble (France); Deves, Guillaume; Ortega, Richard [Univ. Bordeaux, CENBG, UMR 5797, F-33170 Gradignan (France); CNRS, IN2P3, CENBG, UMR 5797, F-33170 Gradignan (France); Bohic, Sylvain [European Synchrotron Radiation Facility, 38000 Grenoble (France); INSERM U-836 (Team 6: Synchrotron Radiation and Medical Research), Grenoble Institut of Neuroscience, F-38000 Grenoble (France)

    2012-12-24

    Hard X-ray fluorescence microscopy and magnified phase contrast imaging are combined to study radiation effects on cells. Experiments were performed on freeze-dried cells at the nano-imaging station ID22NI of the European synchrotron radiation facility. Quantitative phase contrast imaging provides maps of the projected mass and is used to evaluate the structural changes due to irradiation during X-ray fluorescence experiments. Complementary to phase contrast imaging, scanning transmission ion microscopy is performed and doses of all the experiments are compared. We demonstrate the sensitivity of the proposed approach to study radiation-induced damage at the sub-cellular level.

  5. Discovery of a broad O VIII Ly alpha line in the ultra-compact X-ray binary 4U 1543-624

    OpenAIRE

    Madej, O.K.; Jonker, P. G

    2010-01-01

    We report the discovery of a broad emission feature at ~0.7 keV in the spectra of the ultra-compact X-ray binary 4U 1543-624, obtained with the high-resolution spectrographs of the XMM-Newton and Chandra satellites. We confirm the presence of the feature in the broad band MOS2 spectrum of the source. As suggested before in the literature, the donor star in this source is a CO or ONe white dwarf, which transfers oxygen-rich material to the accretor, conceivably a neutron star. The X-rays repro...

  6. X-ray crystallography

    Science.gov (United States)

    2001-01-01

    X-rays diffracted from a well-ordered protein crystal create sharp patterns of scattered light on film. A computer can use these patterns to generate a model of a protein molecule. To analyze the selected crystal, an X-ray crystallographer shines X-rays through the crystal. Unlike a single dental X-ray, which produces a shadow image of a tooth, these X-rays have to be taken many times from different angles to produce a pattern from the scattered light, a map of the intensity of the X-rays after they diffract through the crystal. The X-rays bounce off the electron clouds that form the outer structure of each atom. A flawed crystal will yield a blurry pattern; a well-ordered protein crystal yields a series of sharp diffraction patterns. From these patterns, researchers build an electron density map. With powerful computers and a lot of calculations, scientists can use the electron density patterns to determine the structure of the protein and make a computer-generated model of the structure. The models let researchers improve their understanding of how the protein functions. They also allow scientists to look for receptor sites and active areas that control a protein's function and role in the progress of diseases. From there, pharmaceutical researchers can design molecules that fit the active site, much like a key and lock, so that the protein is locked without affecting the rest of the body. This is called structure-based drug design.

  7. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... Resources Professions Site Index A-Z X-ray (Radiography) - Bone Bone x-ray uses a very small ... X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) is a noninvasive medical ...

  8. Bone X-Ray (Radiography)

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    Full Text Available ... Professions Site Index A-Z X-ray (Radiography) - Bone Bone x-ray uses a very small dose ... limitations of Bone X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) is ...

  9. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... News Physician Resources Professions Site Index A-Z X-ray (Radiography) - Bone Bone x-ray uses a very ... of Bone X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) is a noninvasive ...

  10. Lumbosacral spine x-ray

    Science.gov (United States)

    X-ray - lumbosacral spine; X-ray - lower spine ... The test is done in a hospital x-ray department or your health care provider's office by an x-ray technician. You will be asked to lie on the x-ray table ...

  11. Bone X-Ray (Radiography)

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z X-ray (Radiography) - Bone Bone x-ray uses a very ... of Bone X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) is a noninvasive ...

  12. Abdomen X-Ray (Radiography)

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z X-ray (Radiography) - Abdomen Abdominal x-ray uses a very ... of an abdominal x-ray? What is abdominal x-ray? An x-ray (radiograph) is a noninvasive medical ...

  13. X-ray apparatus

    International Nuclear Information System (INIS)

    A patient support system for X-ray equipment in arteriographic studies of the heart is described in detail. The support system has been designed to overcome many of the practical problems encountered in using previous types of arteriographic X-ray equipment. The support system is capable of horizontal movement and, by a series of shafts attached to the main support system, the X-ray source and image intensifier or detector may be rotated through the same angle. The system is highly flexible and details are given of several possible operational modes. (U.K.)

  14. X-ray lasers

    CERN Document Server

    Elton, Raymond C

    2012-01-01

    The first in its field, this book is both an introduction to x-ray lasers and a how-to guide for specialists. It provides new entrants and others interested in the field with a comprehensive overview and describes useful examples of analysis and experiments as background and guidance for researchers undertaking new laser designs. In one succinct volume, X-Ray Lasers collects the knowledge and experience gained in two decades of x-ray laser development and conveys the exciting challenges and possibilities still to come._Add on for longer version of blurb_M>The reader is first introduced

  15. X-Ray Diffraction.

    Science.gov (United States)

    Smith, D. K.; Smith, K. L.

    1980-01-01

    Reviews applications in research and analytical characterization of compounds and materials in the field of X-ray diffraction, emphasizing new developments in applications and instrumentation in both single crystal and powder diffraction. Cites 414 references. (CS)

  16. Medical X-Rays

    Science.gov (United States)

    ... The Conference of Radiation Control Program Directors (CRCPD) publishes Suggested State Regulations for the Control of Radiation , ... eSubmitter Guidance for Industry and Food and Drug Administration Staff - Assembler's Guide to Diagnostic X-Ray Equipment ...

  17. Chest X-Ray

    Medline Plus

    Full Text Available ... also be useful to help diagnose and monitor treatment for a variety of lung conditions such as pneumonia, emphysema and cancer. A chest x-ray requires no special preparation. ...

  18. Chest X-Ray

    Medline Plus

    Full Text Available ... However, it’s important to consider the likelihood of benefit to your health. While a chest x-ray use a tiny dose of ionizing radiation, the benefit of an accurate diagnosis far outweighs any risk. ...

  19. Chest X-Ray

    Medline Plus

    Full Text Available ... chest x-ray is used to evaluate the lungs, heart and chest wall and may be used ... diagnose and monitor treatment for a variety of lung conditions such as pneumonia, emphysema and cancer. A ...

  20. Chest X-Ray

    Medline Plus

    Full Text Available ... Angioplasty & vascular stenting Video: Arthrography Video: Contrast Material Radiology and You Take our survey About this Site ... radiologist explains chest x-ray. Transcript Welcome to Radiology Info dot org! Hello, I’m Dr. Geoffrey ...

  1. Chest X-Ray

    Medline Plus

    Full Text Available ... of ionizing radiation, the benefit of an accurate diagnosis far outweighs any risk. For more information about chest x-rays, visit Radiology Info dot org. Thank you for your time! ...

  2. Chest X-Ray

    Medline Plus

    Full Text Available ... Site Index A-Z Spotlight June is Men's Health Month Recently posted: Focused Ultrasound for Uterine Fibroids ... to consider the likelihood of benefit to your health. While a chest x-ray use a tiny ...

  3. X-ray tubes

    International Nuclear Information System (INIS)

    An improved form of x-ray tube is described which consists of a rotatable anode disc and an electron beam source enclosed in an envelope. The beam of electrons strikes the edge of the anode disc at an acute angle, producing x-rays which are transmitted through a window in the envelope. To improve performance and life of the anode disc it is additionally reciprocated back and forth along its axis of rotation. Dimensions are specified. (U.K.)

  4. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... around or in bones. top of page How should I prepare? Most bone x-rays require no ... might interfere with the x-ray images. Women should always inform their physician and x-ray technologist ...

  5. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... drawer under the table holds the x-ray film or image recording plate . Sometimes the x-ray ... extended over the patient while an x-ray film holder or image recording plate is placed beneath ...

  6. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... current x-ray images for diagnosis and disease management. top of page How is the procedure performed? ... standards used by radiology professionals. Modern x-ray systems have very controlled x-ray beams and dose ...

  7. X-ray laser

    International Nuclear Information System (INIS)

    X-ray is among the most important research tools today, and has given priceless contributions to all disciplines within the natural sciences. State of the art in this field is called XFEL, X-ray Free Electron Laser, which may be 10 thousand million times stronger than the x-rays at the European Synchrotron Radiation Facility in Grenoble. In addition XFEL has properties that allow the study of processes which previously would have been impossible. Of special interest are depictions on atomic- and molecular level by the use of x-ray holographic methods, and being able to study chemical reactions in nature's own timescale, the femtosecond. Conclusion: The construction of x-ray lasers is a natural development in a scientific field which has an enormous influence on the surrounding society. While the discovery of x-ray was an important breakthrough in itself, new applications appear one after the other: Medical depiction, dissemination, diffraction, DNA and protein structures, synchrotron radiation and tomography. There is reason to believe that XFEL implies a technological leap as big as the synchrotrons some decades ago. As we are now talking about studies of femtosecond and direct depiction of chemical reactions, it is obvious that we are dealing with a revolution to come, with extensive consequences, both scientifically and culturally. (EW)

  8. A cartography of K{beta} resonant inelastic X-ray scattering for lifetime-broadening-suppressed spin-selected XANES of {alpha}-Fe{sub 2}O{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, Hisashi [Department of Chemical and Biological Sciences, Faculty of Science, Japan Women' s University, 2-8-1 Mejirodai, Bunkyo, Tokyo 112-8681 (Japan)], E-mail: hayashih@fc.jwu.ac.jp; Azumi, Tomofumi; Sato, Atsushi; Udagawa, Yasuo [IMRAM, Tohoku University, Katahira 2-1-1, Aoba, Sendai 980-8577 (Japan)

    2008-12-15

    A series of K{beta} resonant inelastic X-ray scattering (RIXS) spectra of {alpha}-Fe{sub 2}O{sub 3} is presented as two-dimensional RIXS maps and analyzed in terms of the Kramers-Heisenberg equation. Genuine lifetime-broadening-suppressed (LBS) spin-selected oscillator strength distributions, which are consistent with Hund's rule, are deduced. It is shown that 2D maps can highlight implications of RIXS results to reveal existences and characteristics of electronic states which are hidden in absorption spectra.

  9. X-ray nanotomography

    Science.gov (United States)

    Sasov, Alexander

    2004-10-01

    A compact laboratory x-ray "nano-CT" scanner has been created for 3D non-invasive imaging with 150-200 nanometers 3D spatial resolution, using advanced x-ray technologies and specific physical phenomena for signal detection. This spatial resolution in volume terms is 3 orders better than can be achieved in synchrotron tomography, 5 orders better then in existing laboratory micro-CT instruments and 10-12 orders better in comparison to clinical CT. The instrument employs an x-ray source with a 300-400nm x-ray spot size and uses small-angle scattering to attain a detail detectability of 150-200nm. An object manipulator allows positioning and rotation with an accuracy of 150nm. The x-ray detector is based on an intensified CCD with single-photon sensitivity. A typical acquisition cycle for 3D reconstruction of the full object volume takes from 10 to 60 minutes, with the collection of several hundred angular views. Subsequent volumetric reconstruction produces results as a set of cross sections with isotropic voxel size down to 140 x 140 x 140nm, or as a 3D-model, which can be virtually manipulated and measured. This unique spatial resolution in non-invasive investigations gives previously unattainable 3D images in several application areas, such as composite materials, paper and wood microstructure, biomedical applications and others.

  10. X-ray Pulsars

    CERN Document Server

    Walter, Roland

    2016-01-01

    X-ray pulsars shine thanks to the conversion of the gravitational energy of accreted material to X-ray radiation. The accretion rate is modulated by geometrical and hydrodynamical effects in the stellar wind of the pulsar companions and/or by instabilities in accretion discs. Wind driven flows are highly unstable close to neutron stars and responsible for X-ray variability by factors $10^3$ on time scale of hours. Disk driven flows feature slower state transitions and quasi periodic oscillations related to orbital motion and precession or resonance. On shorter time scales, and closer to the surface of the neutron star, X-ray variability is dominated by the interactions of the accreting flow with the spinning magnetosphere. When the pulsar magnetic field is large, the flow is confined in a relatively narrow accretion column, whose geometrical properties drive the observed X-ray emission. In low magnetized systems, an increasing accretion rate allows the ignition of powerful explosive thermonuclear burning at t...

  11. X-ray astronomy

    International Nuclear Information System (INIS)

    This book contains the lectures, and the most important seminars held at the NATO meeting on X-Ray astronomy in Erice, July 1979. The meeting was an opportune forum to discuss the results of the first 8-months of operation of the X-ray satellite, HEAO-2 (Einstein Observatory) which was launched at the end of 1978. Besides surveying these results, the meeting covered extragalactic astronomy, including the relevant observations obtained in other portions of the electromagnetic spectrum (ultra-violet, optical, infrared and radio). The discussion on galactic X-ray sources essentially covered classical binaries, globular clusters and bursters and its significance to extragalactic sources and to high energy astrophysics was borne in mind. (orig.)

  12. CRL X-RAY TUBE

    OpenAIRE

    Kolchevsky, N. N.; Petrov, P. V.

    2015-01-01

    A novel types of X-ray tubes with refractive lenses are proposed. CRL-R X-ray tube consists of Compound Refractive Lens- CRL and Reflection X-ray tube. CRL acts as X-ray window. CRL-T X-ray consists of CRL and Transmission X-ray tube. CRL acts as target for electron beam. CRL refractive lens acts as filter, collimator, waveguide and focusing lens. Properties and construction of the CRL X-ray tube are discussed.

  13. X-ray astronomical spectroscopy

    Science.gov (United States)

    Holt, Stephen S.

    1987-01-01

    The contributions of the Goddard group to the history of X-ray astronomy are numerous and varied. One role that the group has continued to play involves the pursuit of techniques for the measurement and interpretation of the X-ray spectra of cosmic sources. The latest development is the selection of the X-ray microcalorimeter for the Advanced X-ray Astrophysics Facility (AXAF) study payload. This technology is likely to revolutionize the study of cosmic X-ray spectra.

  14. Lethal Sectoring, genomic instability and cell cycle variation of HeLa S3 cells survived after alpha- and X-ray irradiation

    International Nuclear Information System (INIS)

    When cells with infinite growth ability are irradiated by radiation, survived cells occasionally yield cells without colony forming ability after several generations (lethal sectoring). The sectoring is the process to exclude cells with latent lethal damage, which results in the inhibition of cell cycle progression. Further, clonogen still having the infinite growth ability appears during the sectoring process and has genomic instability. The present study was conducted to compare these processes after irradiation of α- and X-ray. A time-lapse motion camera (1 picture/15 min) was used for microscopic recording of HeLa S3-9IV cells within a single scope (about 50 cells). They were irradiated by 0.45 Gy of α-ray (point source of 241Am, fluence rate 1.5 x 106/cm2/min, 0.3 Gy/min, LET=125 keV/μm) or 3 Gy of X-ray (200 kVp, 0.7 Gy/min), of which doses were equivalent to the survival rate of 0.2. The film recording was done for 30 and 150 hr before and after irradiation, respectively, from which the pedigree of individual cells was figured out by selection of surviving clonogen. Analysis of the pedigree of the survived cells revealed that there was an essential difference in the three processes, which was possibly based on the LET difference. (N.I.)

  15. X-ray apparatus

    International Nuclear Information System (INIS)

    The invention discloses an X-ray apparatus that can be used for tomography with the aid of a computer. With this apparatus plus computer, it is possible to quickly achieve the required edge values whereby the influence of the movement is diminished

  16. Chest X-Ray

    Medline Plus

    Full Text Available ... Pediatric Ultrasound Video: Angioplasty & vascular stenting Video: Arthrography Radiology and You About this Site RadiologyInfo.org is ... radiologist explains chest x-ray. Transcript Welcome to Radiology Info dot org! Hello, I’m Dr. Geoffrey ...

  17. Medical x-ray

    International Nuclear Information System (INIS)

    This book describes the fundamental subject about medical radiography. It is a multidisciplinary field that requires cross professional input from scientists, engineers and medical doctors. However, it is presented in simple language to suit different levels of readers from x-ray operators and radiographers to physists, general practitioners and radiology specialists.The book is written in accordance to the requirements of the standard syllabus approved by the Ministry of Health Malaysia for the training of medical x-ray operator and general practitioners. In general, the content is not only designed to provide relevant and essential subject for related professionals in medical radiological services such as x-ray operator, radiographer and radiologists, but also to address those in associated radiological services including nurses, medical technologists and physicists.The book is organized and arranged sequentially into 3 parts for easy reference: Radiation safety; X-ray equipment and associated facilities; Radiography practices. With proper grasping of all these parts, the radiological services could be provided with confident and the highest professional standard. Thus, medical imaging with highest quality that can provide useful diagnostic information at minimum doses and at cost effective could be assured

  18. Chest X-Ray

    Medline Plus

    Full Text Available ... this Site RadiologyInfo.org is produced by: Image/Video Gallery Your radiologist explains chest x-ray. Transcript ... Recently posted: Focused Ultrasound for Uterine Fibroids Dementia Video: General Ultrasound Video: Pediatric Nuclear Medicine Radiology and ...

  19. Chest X-Ray

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    Full Text Available ... this Site RadiologyInfo.org is produced by: Image/Video Gallery Your radiologist explains chest x-ray. Transcript ... time! Spotlight Recently posted: Pediatric MRI Intravascular Ultrasound Video: Chest CT Video:Thyroid Ultrasound Video: Head CT ...

  20. Pyroelectric x-ray detectors and x-ray pyrometers

    International Nuclear Information System (INIS)

    This paper discusses pyroelectric detectors which are very promising x-ray detectors for intense pulsed x-ray/γ-ray measurements and can be used as x-ray pyrometers. They are fast, passive, and inherently flat in spectral response for low energy x-rays. The authors report tests of LiTaO3, Sr.5Ba.5Nb2O6 and LiNbO3 detectors at Nova laser with 1 ns low energy x-rays and at Zapp Z-pinch machine with 100 ns x-rays. The temporal and spectral responses are discussed

  1. Pyroelectric x-ray detectors and x-ray pyrometers

    International Nuclear Information System (INIS)

    Pyroelectric detectors are very promising x-ray detectors for intense pulsed x-ray/γ-ray measurements and can be used as x-ray pyrometers. They are fast, passive, and inherently flat in spectral response for low-energy x rays. We report our tests of LiTaO3 detectors at Nova laser with 1-ns low-energy x rays and at Zapp Z-pinch machine with 100-ns x rays. The temporal and spectral responses are discussed

  2. X ray Production. Chapter 5

    International Nuclear Information System (INIS)

    The differential absorption of X rays in tissues and organs, owing to their atomic composition, is the basis for the various imaging methods used in diagnostic radiology. The principles in the production of X rays have remained the same since their discovery. However, much refinement has gone into the design of X ray tubes to achieve the performance required for today’s radiological examinations. In this chapter, an outline of the principles of X ray production and a characterization of the radiation output of X ray tubes will be given. The basic processes producing X rays are dealt with in Section 1.4

  3. X-ray microtomography

    International Nuclear Information System (INIS)

    In this paper the authors describe the application of a new high-resolution X-ray tomographic microscope to the study of porous media. The microscope was designed to exploit the properties of a synchrotron X-ray source to perform three dimensional tomography on millimeter sized objects with micron resolution and has been used in materials science studies with both synchrotron and conventional and synchrotron sources will be compared. In this work the authors have applied the microscope to measure the three dimensional structure of fused bead packs and berea sandstones with micron resolution and have performed preliminary studies of flow in these media with the microscope operated in a digital subtraction radiography mode. Computer graphics techniques have been applied to the data to visually display the structure of the pore body system. Tomographic imaging after flow experiments should detect the structure of the oil-water interface in the pore network and this work is ongoing

  4. X-ray generators

    International Nuclear Information System (INIS)

    Volume 4 provides a comparative survey on generators for stationary applications as available on the German market. It provides decision-making tools, physical characteristics, suggestions for radiation protection and for safe appliance operation as well as a concept for inspections all of which have been developed jointly by physicians of various specialities, physicists, engineers, business men, hospital experts and medicotechnical X-ray staff on the basis of a well-tried working concept. The systematic representation of correlations relevant to decision-making processes is based on a profile of technico-physical characteristics (standard product information) which was established by way of interdisciplinary dialog and which will enable any hospital or clinic to easily equip its X-ray department in an economic and purposeful way. The information on device data, device descriptions and market survey furnish the data tested by the manufacturers without guarantee and subject to correction. (orig./HP)

  5. X-ray lithography

    International Nuclear Information System (INIS)

    An invention relating to the development of photo-resists used in X-ray lithography is described. A COP resist which has been exposed to X-ray radiation, is developed with methyl ethyl ketone (MEK) developer and an ethanol solvent. The resist is first developed in a strong developing solution and then with a weaker developer whose concentration is slightly above that required to obtain complete development. Preferably the resist is exposed so as to obtain about a fifty per cent developed thickness and the developing is carried out in steps, the first with a concentration of 5:1.8 (MEK to ethanol) for five seconds, the second using concentrations of 5:1.8 and 5:2.7 for ten seconds and the third with a concentration of 5:2.7 for five seconds. (author)

  6. X-ray diffraction

    International Nuclear Information System (INIS)

    We have been interested in structural elucidation by x-ray diffraction of compounds of biological interest. Understanding exactly how atoms are arranged in three-dimensional arrays as molecules can help explain the relationship between structure and functions. The species investigated may vary in size and shape; our recent studies included such diverse substances as antischistosomal drugs, a complex of cadmium with nucleic acid base, nitrate salts of adenine, and proteins

  7. X-ray scattering measurements from thin-foil x-ray mirrors

    DEFF Research Database (Denmark)

    Christensen, Finn Erland; BYRNAK, BP; Hornstrup, Allan;

    1992-01-01

    Thin foil X-ray mirrors are to be used as the reflecting elements in the telescopes of the X-ray satellites Spectrum-X-Gamma (SRG) and ASTRO-D. High resolution X-ray scattering measurements from the Au coated and dip-lacquered Al foils are presented. These were obtained from SRG mirrors positioned...... in a test quadrant of the telescope structure and from ASTRO-D foils held in a simple fixture. The X-ray data is compared with laser data and other surface structure data such as STM, atomic force microscopy (AFM), TEM, and electron micrography. The data obtained at Cu K-alpha(1), (8.05 keV) from all...

  8. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... foot. top of page What are some common uses of the procedure? A bone x-ray is ... care is taken during x-ray examinations to use the lowest radiation dose possible while producing the ...

  9. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... current x-ray images for diagnosis and disease management. top of page How is the procedure performed? ... top of page What are the benefits vs. risks? Benefits Bone x-rays are the fastest and ...

  10. Dental X-ray apparatus

    International Nuclear Information System (INIS)

    Intra-oral dental X-ray apparatus for panoramic radiography is described in detail. It comprises a tubular target carrier supporting at its distal end a target with an inclined forward face. Image definition is improved by positioning in the path of the X-rays a window of X-ray transmitting ceramic material, e.g. 90% oxide of Be, or Al, 7% Si02. The target carrier forms a probe which can be positioned in the patient's mouth. X-rays are directed forwardly and laterally of the target to an X-ray film positioned externally. The probe is provided with a detachable sleeve having V-form arms of X-ray opaque material which serve to depress the tongue out of the radiation path and also shield the roof of the mouth and other regions of the head from the X-ray pattern. A cylindrical lead shield defines the X-ray beam angle. (author)

  11. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... current x-ray images for diagnosis and disease management. top of page How is the procedure performed? ... position possible that still ensures x-ray image quality. top of page Who interprets the results and ...

  12. Soft X-ray Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Seely, John

    1999-05-20

    The contents of this report cover the following: (1) design of the soft x-ray telescope; (2) fabrication and characterization of the soft x-ray telescope; and (3) experimental implementation at the OMEGA laser facility.

  13. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... and x-rays. A Word About Minimizing Radiation Exposure Special care is taken during x-ray examinations ... patient's body not being imaged receive minimal radiation exposure. top of page What are the limitations of ...

  14. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... images for evaluation. National and international radiology protection organizations continually review and update the technique standards used by radiology professionals. Modern x-ray systems have very controlled x-ray beams and dose ...

  15. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... fracture. guide orthopedic surgery, such as spine repair/fusion, joint replacement and fracture reductions. look for injury, ... and Media Arthritis X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety Images related to X-ray ( ...

  16. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... As a result, bones appear white on the x-ray, soft tissue shows up in shades of gray and air appears black. Until recently, x-ray images were maintained on large film sheets (much ...

  17. Panoramic Dental X-Ray

    Science.gov (United States)

    ... Physician Resources Professions Site Index A-Z Panoramic Dental X-ray Panoramic dental x-ray uses a ... a large photographic negative). Today, most images are digital files that are stored electronically. These stored images ...

  18. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... that helps physicians diagnose and treat medical conditions. Imaging with x-rays involves exposing a part of ... oldest and most frequently used form of medical imaging. A bone x-ray makes images of any ...

  19. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... wrist, arm, elbow, shoulder, spine, pelvis, hip, thigh, knee, leg (shin), ankle or foot. top of page ... the patient standing upright, as in cases of knee x-rays. A portable x-ray machine is ...

  20. Active X-ray Optics

    Czech Academy of Sciences Publication Activity Database

    Hudec, René; Inneman, A.; Pina, L.; Černá, D.; Tichý, V.

    Bellingham: SPIE, 2013 - (Juha, L.; Bajt, S.; London, R.; Hudec, R.; Pína, L.), 877718/1-877718/7. (Proceedings of SPIE. 8777). ISBN 9780819495792. [Damage to VUV, EUV, and X-ray Optics IV; and EUV and X-ray Optics: Synergy between Laboratory and Space III. Praha (CZ), 15.04.2013-18.04.2013] Institutional support: RVO:67985815 Keywords : X-ray optics * active optics * active X-ray optics Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  1. X-ray Crystallography Facility

    Science.gov (United States)

    2000-01-01

    Edward Snell, a National Research Council research fellow at NASA's Marshall Space Flight Center (MSFC), prepares a protein crystal for analysis by x-ray crystallography as part of NASA's structural biology program. The small, individual crystals are bombarded with x-rays to produce diffraction patterns, a map of the intensity of the x-rays as they reflect through the crystal.

  2. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... lies. A drawer under the table holds the x-ray film or image recording plate . Sometimes the x-ray ... that is extended over the patient while an x-ray film holder or image recording plate is placed beneath ...

  3. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... x-rays. top of page What does the equipment look like? The equipment typically used for bone x-rays consists of ... and joint abnormalities, such as arthritis. X-ray equipment is relatively inexpensive and widely available in emergency ...

  4. Tunable X-ray source

    Science.gov (United States)

    Boyce, James R.

    2011-02-08

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

  5. X-Ray Exam: Ankle

    Science.gov (United States)

    ... Tropical Delight: Melon Smoothie Pregnant? Your Baby's Growth X-Ray Exam: Ankle KidsHealth > For Parents > X-Ray Exam: Ankle Print A A A Text Size ... español Radiografía: tobillo What It Is An ankle X-ray is a safe and painless test that uses ...

  6. X-Ray Exam: Finger

    Science.gov (United States)

    ... Tropical Delight: Melon Smoothie Pregnant? Your Baby's Growth X-Ray Exam: Finger KidsHealth > For Parents > X-Ray Exam: Finger Print A A A Text Size ... español Radiografía: dedo What It Is A finger X-ray is a safe and painless test that uses ...

  7. X-Ray Exam: Wrist

    Science.gov (United States)

    ... Tropical Delight: Melon Smoothie Pregnant? Your Baby's Growth X-Ray Exam: Wrist KidsHealth > For Parents > X-Ray Exam: Wrist Print A A A Text Size ... español Radiografía: muñeca What It Is A wrist X-ray is a safe and painless test that uses ...

  8. X-Ray Exam: Hip

    Science.gov (United States)

    ... Tropical Delight: Melon Smoothie Pregnant? Your Baby's Growth X-Ray Exam: Hip KidsHealth > For Parents > X-Ray Exam: Hip Print A A A Text Size ... español Radiografía: cadera What It Is A hip X-ray is a safe and painless test that uses ...

  9. X-Ray Exam: Forearm

    Science.gov (United States)

    ... Tropical Delight: Melon Smoothie Pregnant? Your Baby's Growth X-Ray Exam: Forearm KidsHealth > For Parents > X-Ray Exam: Forearm Print A A A Text Size ... español Radiografía: brazo What It Is A forearm X-ray is a safe and painless test that uses ...

  10. X-Ray Exam: Pelvis

    Science.gov (United States)

    ... Tropical Delight: Melon Smoothie Pregnant? Your Baby's Growth X-Ray Exam: Pelvis KidsHealth > For Parents > X-Ray Exam: Pelvis Print A A A Text Size ... español Radiografía: pelvis What It Is A pelvis X-ray is a safe and painless test that uses ...

  11. X-Ray Exam: Foot

    Science.gov (United States)

    ... Tropical Delight: Melon Smoothie Pregnant? Your Baby's Growth X-Ray Exam: Foot KidsHealth > For Parents > X-Ray Exam: Foot Print A A A Text Size ... español Radiografía: pie What It Is A foot X-ray is a safe and painless test that uses ...

  12. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... The x-ray tube is connected to a flexible arm that is extended over the patient while an x-ray film holder or image recording plate is placed beneath the patient. top of page How does the procedure work? X-rays are a form of radiation like ...

  13. The PG X-Ray QSO Sample Links among X-ray, UV & Optical Spectra

    CERN Document Server

    Wills, B J; Laor, A; Wills, D; Wilkes, B J; Ferland, G J; Wills, Beverley J.

    1998-01-01

    A unique, essentially complete sample of 22 QSOs, with high quality soft X-ray spectra from ROSAT, as well as HST and optical spectrophotometry from below Ly-alpha to above H-alpha, is being used to investigate the relationships among the ionizing continuum and the optical and UV continuum, emission and absorption lines. Here we present a first analysis showing that optical `Eigenvector 1' linking steeper soft X-ray spectra with increasing optical Fe II strength, decreasing [O III] 5007 emission, and narrower BLR H-beta emission, extends to the UV emission lines, and is manifested by weaker C IV 1549 emission, stronger Si III] 1892/C III] 1909 ratio, and narrower C III] 1909 emission. Steeper soft X-ray spectra have been linked to higher L/L_Edd ratios, thus apparently linking BLR densities, high and low ionization gas, and kinematics, to the accretion process.

  14. X-ray Pulsation Searches with NICER

    Science.gov (United States)

    Ray, Paul S.; Arzoumanian, Zaven

    2016-04-01

    The Neutron Star Interior Composition Explorer (NICER) is an X-ray telescope with capabilities optimized for the study of the structure, dynamics, and energetics of neutron stars through high-precision timing of rotation- and accretion-powered pulsars in the 0.2-12 keV band. It has large collecting area (twice that of the XMM-Newton EPIC-pn camera), CCD-quality spectral resolution, and high-precision photon time tagging referenced to UTC through an onboard GPS receiver. NICER will begin its 18-month prime mission as an attached payload on the International Space Station around the end of 2016. I will describe the science planning for the pulsation search science working group, which is charged with searching for pulsations and studying flux modulation properties of pulsars and other neutron stars. A primary goal of our observations is to detect pulsations from new millisecond pulsars that will contribute to NICER’s studies of the neutron star equation of state through pulse profile modeling. Beyond that, our working group will search for pulsations in a range of source categories, including LMXBs, new X-ray transients that might be accreting millisecond pulsars, X-ray counterparts to unassociated Fermi LAT sources, gamma-ray binaries, isolated neutron stars, and ultra-luminous X-ray sources. I will survey our science plans and give an overview of our planned observations during NICER’s prime mission.

  15. X-ray diffraction

    International Nuclear Information System (INIS)

    The seventh edition of Philips' Review of literature on X-ray diffraction begins with a list of conference proceedings on the subject, organised by the Philips' organisation at regular intervals in various European countries. This is followed by a list of bulletins. The bibliography is divided according to the equipment (cameras, diffractometers, monochromators) and its applications. The applications are subdivided into sections for high/low temperature and pressure, effects due to the equipment, small angle scattering and a part for stress, texture and phase analyses of metals and quantitative analysis of minerals

  16. X-ray detector

    International Nuclear Information System (INIS)

    The multicell X-ray or gamma detector is used in computer tomography. To achieve good spatial resolution, the electrode plates are narrowly spaced in each cell and are designed identical over the whole length of the detector group. The uniform spacing and precise check of the angles between the electrodes and accurate control of the dimensions of the whole detector structure are achieved by depositing, in the fabrication process, a viscous, resin type material (e.g., epoxy resin) or glue at selected points between the electrodes and insulators. (ORU)

  17. Alpha-actinin expression at different differentiating time points from temporal lobe cerebral cortex neural stem cells to neuron-like cells using energy dispersive X-ray analysis

    Institute of Scientific and Technical Information of China (English)

    Bo YU; Hua Li; Zhe Du; Yang Hong; Meng Sang; Yuxiu Shi

    2009-01-01

    BACKGROUND: Alpha-actinin (a-actinin) plays a key role in neuronal growth cone migration during directional differentiation from neural stem cells (NSCs) to neurons.OBJECTIVE: To detect in situ microdistribution and quantitative expression of a-actinin during directional differentiation of NSCs to neurons in the temporal lobe cerebral cortex of neonatal rats.DESIGN, TIME AND SETTING: Between January 2006 and December 2008, culture and directional differentiation of NSCs were performed at Department of Histology and Embryology, Preclinical Medical College, China Medical University. Immune electron microscopy was performed at Department of Histology and Embryology and Department of Electron Micrology, Preclinical Medical College, China Medical University. Spectrum analysis was performed at Laboratory of Electron Microscopy, Mental Research Institute, Chinese Academy of Sciences.MATERIALS: Basic fibroblast growth factor, epidermal growth factor, brain-derived nerve growth factor, type-1 insulin like growth factor, and a-actinin antibody were provided by Gibco BRL, USA; rabbit-anti-rat nestin monoclonal antibody, rabbit-anti-rat neuron specific enolase polyclonal antibody, and EDAX-9100 energy dispersive X-ray analysis were provided by PHILIPS Company, Netherlands.METHODS: NSCs, following primary and passage culture, were differentiated with serum culture medium (DMEM/F12+10% fetal bovine serum+2 ng/mL brain-derived nerve growth factor+2 ng/mL type-1 insulin like growth factor).MAIN OUTCOME MEASURES: Expression of a-actinin in neuron-like cells was quantitatively and qualitatively detected with immunocytochemistry using energy dispersive X-ray analysis. RESULTS: Immunocytochemistry, combined with electron microscopy, indicated that positive a-actinin expression was like a spheroid particle with high electron density. In addition, the expression was gradually concentrated from the nuclear edge to the cytoplasm and expanded into developing neurites, during

  18. High energy x-ray reflectivity and scattering study from spectrum-x-gamma flight mirrors

    DEFF Research Database (Denmark)

    Christensen, Finn Erland; Budtz-Jørgensen, Carl; Frederiksen, P. Kk;

    1993-01-01

    Line radiation from Fe K-alpha(1), Cu K-alpha(1), and Ag K-alpha(1) is used to study the high energy X-ray reflectivity and scattering behavior of flight-quality X-ray mirrors having various Al substrates. When both the specular and the scattered radiation are integrated, near theoretical...

  19. Photoluminescence, FTIR and X-ray diffraction studies on undoped and Al-doped ZnO thin films grown on polycrystalline {alpha}-alumina substrates by ultrasonic spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Djelloul, A., E-mail: djelloulabdelkader@yahoo.f [LASPI2A Laboratoire des Structures, Proprietes et Interactions Inter Atomiques, Centre Universitaire Khenchela (Algeria); Aida, M-S. [Laboratoire des Couches minces et Interface, Universite de Constantine (Algeria); Bougdira, J. [Institut Jean Lamour, UMR 7198 CNRS, Nancy Universite, UPV-Metz, Faculte des Sciences et Techniques, B.P. 239, Bd des Aiguillettes, 54506 Vandoeuvre-les-Nancy (France)

    2010-11-15

    Undoped and aluminum-doped zinc oxide (ZnO) thin films have been grown on polycrystalline {alpha}-alumina substrates by ultrasonic spray pyrolysis (USP) technique using zinc acetate dihydrate and aluminum chloride hexahydrate (Al source) dissolved in methanol, ethanol and deionized water. A number of techniques, including X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and photoluminescence (PL) were used to characterize the obtained ZnO thin films. It was seen that the orientation changed with increase in substrate temperature. During the ZnO deposition Zn source reacted with polycrystalline {alpha}-Al{sub 2}O{sub 3} substrate to form an intermediate ZnAl{sub 2}O{sub 4} spinel layer. It has been interestingly found that the intensity of green emission at 2.48 eV remarkably increased when the obtained ZnO:Al films were deposited at 380 {sup o}C. The FTIR absorbance intensity of spectroscopic band at 447{+-}6 cm{sup -1} is very sensitive to oxygen sublattice disorder resulting from non-stoichiometry, which is consistent with the result of PL characterization.

  20. Characterization of local chemistry and disorder in synthetic and natural {alpha}-Al{sub 2}O{sub 3} materials by X-ray absorption near edge structure spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Mottana, A. [Rome, Univ. `Roma Tre` (Italy). Dip. di Scienze Geologiche]|[INFN, Laboratori Nazionali di Frascati, Rome (Italy); Murata, T. [Kyoto, Univ. of Education (Japan). Dept. of Physics; Marcelli, A. [INFN, Laboratori Nazionali di Frascati, Rome (Italy)] [and others

    1997-11-01

    X-ray absorption fine spectra at the Al K-edge were measured experimentally on and calculated theoretically via the multiple-scattering formalism for a chemically pure and physically perfect synthetic {alpha}-Al{sub 2}O{sub 3} ({alpha}-alumina), a natural `ruby/sapphire` (corundum) and a series of artificial `corundum` produced for technical purposes and used as geochemical standards. The Al K-edge spectra differ despite of the identical coordination (short-range arrangement) assumed by O around Al, and vary slightly in relation to the slightly different chemistries of the materials (substitutional defects) as well as on account of the location taken by foreign atoms in the structural lattices (positional defects). A quantitative treatment of the observed changes is made in terms of short-range modification of the coordination polyhedron and of medium- to long-range modifications in the overall structure; both of them induced by substitutions. In some technical `corundums`, the impurities of admixed `{beta}-alumina`, where Al is both in four- and six-fold coordination, produce another small but detectable effect on Al K-edges. Therefore, XAFS spectroscopy proves its potentials for both measuring a light element such as Al, and detecting minor coordination changes and substitutions (ca. 1{approx}3 wt.% as oxide) of the absorber by dilute other atoms, at least under favorable conditions as those occurring in this system are.

  1. Detectors for alpha particles and X-rays operating in ambient air in pulse counting mode and/or with gas amplification

    CERN Document Server

    Charpak, Georges; Breuil, P; Peskov, Vladimir

    2008-01-01

    Ionization chambers working in ambient air in current detection mode are widely used in several applications such as smoke detection, dosimetry, therapeutic beam monitoring and cetera. The aim of this work was to investigate if gaseous detectors can operate in ambient air in pulse counting mode as well as with gas amplification. . To investigate the feasibility of this method two types of open- end gaseous detectors were build and successfully tested. The first one was a single wire or multiwire cylindrical geometry detector operating in pulse mode at a gas gain of 1. The second type alpha detector was an innovative GEM-like detector with resistive electrodes operating in air in avalanche mode at high gas gains (up to 10E4). A detailed comparison between these two detectors is given as well as comparison with the commercially available alpha detectors. The main advantages of gaseous detectors operating in air in a pulse detection mode are their simplicity, low cost and high sensitivity. One of the possible ap...

  2. X-ray instrumentation for SR beamlines

    CERN Document Server

    Kovalchuk, M V; Zheludeva, S I; Aleshko-Ozhevsky, O P; Arutynyan, E H; Kheiker, D M; Kreines, A Y; Lider, V V; Pashaev, E M; Shilina, N Y; Shishkov, V A

    2000-01-01

    The main possibilities and parameters of experimental X-ray stations are presented: 'Protein crystallography', 'X-ray structure analysis', 'High-precision X-ray optics', 'X-ray crystallography and material science', 'X-ray topography', 'Photoelectron X-ray standing wave' that are being installed at Kurchatov SR source by A.V. Shubnikov Institute of Crystallography.

  3. X-ray lithography sources

    International Nuclear Information System (INIS)

    Synchrotron from dipole magnets in electron storage rings has emerged as a useful source of x-rays for lithography. To meet the need for these sources numerous groups around the world have embarked on projects to design and construct storage rings for x-ray lithography. Both conventional electromagnets as well as superconducting (SC) dipoles have been incorporated into the various designs. An overview of the worldwide effort to produce commercial x-ray sources will be presented. To better illustrate the elements involved in these sources a closer examination of the Superconducting X-ray Lithography Source Project (SXLS) at BNL will be presented. 11 refs., 1 fig., 5 tabs

  4. X-ray Absorption Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Yano, Junko; Yachandra, Vittal K.

    2009-07-09

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

  5. X-ray Fluorescence Sectioning

    CERN Document Server

    Cong, Wenxiang

    2012-01-01

    In this paper, we propose an x-ray fluorescence imaging system for elemental analysis. The key idea is what we call "x-ray fluorescence sectioning". Specifically, a slit collimator in front of an x-ray tube is used to shape x-rays into a fan-beam to illuminate a planar section of an object. Then, relevant elements such as gold nanoparticles on the fan-beam plane are excited to generate x-ray fluorescence signals. One or more 2D spectral detectors are placed to face the fan-beam plane and directly measure x-ray fluorescence data. Detector elements are so collimated that each element only sees a unique area element on the fan-beam plane and records the x-ray fluorescence signal accordingly. The measured 2D x-ray fluorescence data can be refined in reference to the attenuation characteristics of the object and the divergence of the beam for accurate elemental mapping. This x-ray fluorescence sectioning system promises fast fluorescence tomographic imaging without a complex inverse procedure. The design can be ad...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-02-26

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

  7. X-ray reflection in oxygen-rich accretion discs of ultracompact X-ray binaries

    DEFF Research Database (Denmark)

    Madej, O. K.; Garcia, Jeronimo; Jonker, P. G.;

    2014-01-01

    donor star in these sources is a carbon-oxygen or oxygen-neon-magnesium white dwarf. Hence, the accretion disc is enriched with oxygen which makes the O viii Ly alpha line particularly strong. Modelling the X-ray reflection off a carbon- and oxygen-enriched, hydrogen- and helium-poor disc with models...... assuming solar composition likely biases several of the best-fitting parameters. In order to describe the X-ray reflection spectra self-consistently, we modify the currently available xillver reflection model. We present initial grids that can be used to model X-ray reflection spectra in UCXBs with carbon-oxygen......-rich (and hydrogen- and helium-poor) accretion disc. We find that the new reflection model provides a better overall description of the reflection spectra of 4U 0614+091 and 4U 1543-624 than the reflection models that assume solar abundances....

  8. Radioisotope x-ray analysis

    International Nuclear Information System (INIS)

    Radioisotope x-ray fluorescence and x-ray preferential absorption (XRA) techniques are used extensively for the analysis of materials, covering such diverse applications as analysis of alloys, coal, environmental samples, paper, waste materials, and metalliferous mineral ores and products. Many of these analyses are undertaken in the harsh environment of industrial plants and in the field. Some are continuous on-line analyses of material being processed in industry, where instantaneous analysis information is required for the control of rapidly changing processes. Radioisotope x-ray analysis systems are often tailored to a specific but limited range of applications. They are simpler and often considerably less expensive than analysis systems based on x-ray tubes. These systems are preferred to x-ray tube techniques when simplicity, ruggedness, reliability, and cost of equipment are important; when minimum size, weight, and power consumption are necessary; when a very constant and predictable x-ray output is required; when the use of high-energy x-rays is advantageous; and when short x-ray path lengths are required to minimize the absorption of low-energy x-rays in air. This chapter reviews radioisotope XRF, preferential absorption, and scattering techniques. Some of the basic analysis equations are given. The characteristics of radioisotope sources and x-ray detectors are described, and then the x-ray analytical techniques are presented. The choice of radioisotope technique for a specific application is discussed. This is followed by a summary of applications of these techniques, with a more detailed account given of some of the applications, particularly those of considerable industrial importance. 79 refs., 28 figs., 7 tabs

  9. Imaging and nondispersive spectroscopy of soft X rays using a laboratory X-ray charge-coupled-device system

    Science.gov (United States)

    Luppino, Gerard A.; Doty, John P.; Ricker, George R.; Vallerga, John V.; Ceglio, Natale M.

    1987-01-01

    This paper describes the design and performance of a laboratory instrument for imaging and nondispersive spectroscopy of soft X-rays (300 eV to 10 keV) utilizing a virtual-phase CCD. This instrument has achieved a spatial resolution of 22 microns (limited by pixel size) with an overall array area of 584 x 390 pixels. It has achieved an energy resolution of about 140 eV FWHM for single-pixel Fe-55 X-ray events (5.9 keV) with the CCD operated at -30 C. The CCD has been operated in photon-counting mode at room temperature, and X-ray spectra with an energy resolution of about 450 eV at 5.9 keV have been obtained. The low energy X-ray sensitivity of the CCD also has been demonstrated by detecting carbon K-alpha X-rays (277eV).

  10. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos News Physician Resources Professions Site Index A-Z X-ray (Radiography) - Bone Bone x-ray uses a very small dose of ionizing ...

  11. X-ray Dynamic Defectoscopy

    Czech Academy of Sciences Publication Activity Database

    Vavřík, Daniel; Visschers, J.; Jakůbek, J.; Ponchut, C.

    Orosei : IMC S.r.l., 2001. s. 47. [International Workshop on Radiation Imaging Detectors /3./. 23.09.2001-27.09.2001, Orosei] R&D Projects: GA ČR GA106/00/D064 Institutional research plan: CEZ:MSM 210000018 Keywords : X-ray Defectoscopy * Damage * X-ray Detectors Subject RIV: JL - Materials Fatigue, Friction Mechanics

  12. X-ray diagnostic equipment

    International Nuclear Information System (INIS)

    An X-ray tube is connected to several different image processing devices in X-ray diagnostic equipment. Only a single organ selector is allocated to it, for which the picture parameters for each image processing device are selected. The choice of the correct combination of picture parameters is made by means of a selector switch. (DG)

  13. X-ray tube arrangement

    International Nuclear Information System (INIS)

    An x-ray tube is described incorporating an elongated target/ anode over which the electron beam is deflected and from which x-rays are emitted. Improved methods of monitoring and controlling the amplitude of the beam deflection are presented. (U.K.)

  14. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... frequently compared to current x-ray images for diagnosis and disease management. top of page How is the procedure performed? The technologist, an individual specially trained to perform radiology examinations, positions the patient on the x-ray ...

  15. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... clothing that might interfere with the x-ray images. Women should always inform their physician and x-ray ... small burst of radiation that passes through the body, recording an image on photographic film or a special detector. Different ...

  16. X-ray photoelectron spectroscopy

    International Nuclear Information System (INIS)

    The methods and results of X-ray photoelectron spectroscopy in the study of plasmons, alloys and gold compounds are discussed. After a comprehensive introduction, seven papers by the author, previously published elsewhere, are reprinted and these cover a wide range of the uses of X-ray photoelectron spectroscopy. (W.D.L.)

  17. Discovery of X-rays from Mars with Chandra

    CERN Document Server

    Dennerl, K

    2002-01-01

    On 4 July 2001, X-rays from Mars were detected for the first time. The observation was performed with the ACIS-I detector onboard Chandra and yielded data of high spatial and temporal resolution, together with spectral information. Mars is clearly detected as an almost fully illuminated disk, with an indication of limb brightening at the sunward side, accompanied by some fading on the opposite side. The morphology and the X-ray luminosity of ~4 MW are fully consistent with fluorescent scattering of solar X-rays in the upper Mars atmosphere. The X-ray spectrum is dominated by a single narrow emission line, which is most likely caused by O-K_alpha fluorescence. No evidence for temporal variability is found. This is in agreement with the solar X-ray flux, which was almost constant during the observation. In addition to the X-ray fluorescence, there is evidence for an additional source of X-ray emission, indicated by a faint X-ray halo which can be traced to about three Mars radii, and by an additional component ...

  18. X-ray fluorescence analysis of niobium-containing slags by glass bead technique and matrix correction using theoretical alpha coefficients

    International Nuclear Information System (INIS)

    The chemical composition of niobium-containing slags under investigation widely vary in comparison with those of blast furnace slags, converter slags and etc. Accurate analyses of such samples are usually performed using many standard samples. In this report calibration curves were made by using only eight synthetic standard samples prepared from oxides, and the correction was made for the matrix effects using theoretical alpha coefficients. A sample (0.5 g) was fused with Na2B4O7 as a flux (5.0 g), and Co2O3 (0.1 g) plus MoO3 (0.1 g) as internal standards for the analyses of iron and niobium, respectively, in a Pt-5 % Au crucible at 1080 deg C for 14 min. Analytical accuracies (σd) for respective components obtained from the calibration curves with/or without correction as: Nb2O5 (the concentration range: 0 ∼ 20 %) 0.13/0.72, SiO2 (0 ∼ 60 %) 0.14/0.19, Al2O3 (0 ∼ 20 %) 0.15/0.16, Fe2O3 (0 ∼ 30 %) 0.24/1.22, CaO (0 ∼ 50 %) 0.16/0.65, MgO (0 ∼ 20 %) 0.089/0.12, MnO (0 ∼ 50 %) 0.11/1.16. The effects of Nb2O5 and MnO on the determination of other components were studied because the slags contained ca. 8 % of Nb2O5 and ca. 40 % of MnO. It was found that Nb2O5 of less than 20 % and MnO of less than 44 % did not interfere with the determination of other components. The relative standard deviation for each component was in the range of 0.27 ∼ 0.73 % with the exception of MgO (3.31 %). The analytical values showed good agreement with those determined by chemical analysis. (author)

  19. Inner-shell photoionized x-ray lasers

    Energy Technology Data Exchange (ETDEWEB)

    Moon, S.J.

    1998-06-01

    The inner-shell photoionized x-ray lasing scheme is an attractive method for achieving x-ray lasing at short wavelengths, via population inversion following inner-shell photoionization (ISPI). This scheme promises both a short wavelength and a short pulse source of coherent x rays with high average power. In this dissertation a very complete study of the ISPI x-ray laser scheme is done concerning target structure, filter design and lasant medium. An investigation of the rapid rise time of x-ray emission from targets heated by an ultra-short pulse high-intensity optical laser was conducted for use as the x-ray source for ISPI x-ray lasing. Lasing by this approach in C at a wavelength of 45 {angstrom} requires a short pulse (about 50 fsec) driving optical laser with an energy of 1-5 J and traveling wave optics with an accuracy of {approximately} 15 {micro}m. The optical laser is incident on a high-Z target creating a high-density plasma which emits a broadband spectrum of x rays. This x-ray source is passed through a filter to eliminate the low-energy x rays. The remaining high-energy x rays preferentially photoionize inner-shell electrons resulting in a population inversion. Inner-shell photoionized x-ray lasing relies on the large energy of a K-{alpha} transition in the initially neutral lasant. The photo energy required to pump this scheme is only slightly greater than the photon energy of the lasing transition yielding a lasing scheme with high quantum efficiency. However, the overall efficiency is reduced due to low x-ray conversion efficiency and the large probability of Auger decay yielding an overall efficiency of {approximately} 10{sup {minus}7} resulting in an output energy of {micro}J's. They calculate that a driving laser with a pulse duration of 40 fs, a 10{micro}m x 1 cm line focus, and an energy of 1 J gives an effective gain length product (gl) of 10 in C at 45 {angstrom}. At saturation (gl {approximately} 18) they expect an output of

  20. The peculiar optical-UV X-ray spectra of the X-ray weak quasar PG 0043+039

    CERN Document Server

    Kollatschny, W; Zetzl, M; Santos-Lleó, M; Rodríguez-Pascual, P M; Ballo, L; Talavera, A

    2016-01-01

    The object PG 0043+039 has been identified as a broad absorption line (BAL) quasar based on its UV spectra. However, this optical luminous quasar has not been detected before in deep X-ray observations, making it the most extreme X-ray weak quasar known today. This study aims to detect PG 0043+039 in a deep X-ray exposure. The question is what causes the extreme X-ray weakness of PG 0043+039? Does PG 0043+039 show other spectral or continuum peculiarities? We took simultaneous deep X-ray spectra with XMM-Newton, far-ultraviolet (FUV) spectra with the Hubble Space Telescope (HST) and optical spectra of PG 0043+039 with the Hobby-Eberly Telescope (HET) and Southern African Large Telescope (SALT) in July, 2013. We have detected PG 0043+039 in our X-ray exposure taken in 2013. We presented our first results in a separate paper (Kollatschny et al. 2015). PG 0043+039 shows an extreme {\\alpha}_ox gradient ({\\alpha}_ox =-2.37). Furthermore, we were able to verify an X-ray flux of this source in a reanalysis of the X-...

  1. Powerful jets from black hole X-ray binaries in Low/Hard X-ray states

    OpenAIRE

    Fender, R. P.

    2000-01-01

    Four persistent (Cygnus X-1, GX 339-4, GRS 1758-258 and 1E 1740.7-2942) and three transient (GS 2023+38, GRO J0422+32 and GS 1354-64) black hole X-ray binary systems have been extensively observed at radio wavelengths during extended periods in the Low/Hard X-ray state, which is characterised in X-rays by a hard power-law spectrum and strong variability. All seven systems show a persistent flat or inverted (in the sense that spectral index alpha >= 0) radio spectrum in this state, markedly di...

  2. X-ray quasars and the X-ray background

    International Nuclear Information System (INIS)

    The Einstein X-ray observations of a sample of 202 radio-and optically-selected quasars due to Ku, Helfand and Lucy and to Zamorani et al. are analysed. Correlations between X-ray, optical and radio luminosities are examined. The contribution of radio-loud quasars to the 2-keV X-ray background is estimated using high-frequency radio-source counts, and the contribution due to radio-quiet, optically bright quasars using optical counts. It is shown that radio-loud quasars and radio-quiet optically bright quasars together contribute approximately 15 per cent of the observed 2-keV X-ray background. The contribution of optically faint radio-quiet quasars is uncertain, but may be limited to a maximum of approximately 30 per cent if recent indications of a flattening in optical counts at faint magnitudes are correct. (author)

  3. X-ray diffraction apparatus

    International Nuclear Information System (INIS)

    The invention provides an x-ray diffraction apparatus permitting the rotation of the divergence sit in conjunction with the rotation of the x-ray irradiated specimen, whereby the dimensions of the x-ray irradiated portion of the specimen remain substantially constant during the rotation of the specimen. In a preferred embodiment, the divergence slit is connected to a structural element linked with a second structural element connected to the specimen such that the divergence slit rotates at a lower angular speed than the specimen

  4. X-ray crystal interferometers

    International Nuclear Information System (INIS)

    Various configurations of the X-ray crystal interferometer are reviewed. The interferometer applications considered include metrology, the measurement of fundamental physical constants, the study of weakly absorbing phase objects, time-resolved diagnostics, the determination of hard X-ray beam parameters, and the characterization of structural defects in the context of developing an X-ray Michelson interferometer. The three-crystal Laue interferometer (LLL-interferometer), its design, and the experimental opportunities it offers are given particular attention. (instruments and methods of investigation)

  5. TiO2 Nanoparticles as a Soft X-ray Molecular Probe

    Energy Technology Data Exchange (ETDEWEB)

    Larabell, Carolyn; Ashcroft, Jared M.; Gu, Weiwei; Zhang, Tierui; Hughes, Steven M.; Hartman, Keith B.; Hofmann, Cristina; Kanaras, Antonios G.; Kilcoyne, David A.; Le Gros, Mark; Yin, Yadong; Alivisatos, A. Paul; Larabell, Carolyn A.

    2007-06-30

    With the emergence of soft x-ray techniques for imaging cells, there is a pressing need to develop protein localization probes that can be unambiguously identified within the region of x-ray spectrum used for imaging. TiO2 nanocrystal colloids, which have a strong absorption cross-section within the "water-window" region of x-rays, areideally suited as soft x-ray microscopy probes. To demonstrate their efficacy, TiO2-streptavidin nanoconjugates were prepared and subsequently labeled microtubules polymerized from biotinylated tubulin. The microtubules were imaged using scanning transmission x-ray microscopy (STXM), and the TiO2 nanoparticle tags were specifically identified using x-ray absorption near edge spectroscopy (XANES). These experiments demonstrate that TiO2 nanoparticles are potential probes for protein localization analyses using soft x-ray microscopy.

  6. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... x-ray machine produces a small burst of radiation that passes through the body, recording an image on photographic film or a special detector. Different parts of the body absorb the x- ...

  7. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... an image on photographic film or a special detector. Different parts of the body absorb the x-rays in varying degrees. Dense bone absorbs much of the radiation while soft tissue, such as muscle, fat and ...

  8. Duodenal X-ray diagnostics

    International Nuclear Information System (INIS)

    The publication provides an overview of duodenal X-ray diagnostics with the aid of barium meals in 1362 patients. The introducing paragraphs deal with the topographic anatomy of the region and the methodics of X-ray investigation. The chapter entitled ''processes at the duodenum itself'' describes mainly ulcers, diverticula, congenital anomalies, tumors and inflammations. The neighbourhood processes comprise in the first place diseases having their origin at the pancreas and bile ducts. As a conclusion, endoscopic rectograde cholangio-pancreaticography and percutaneous transhepatic cholangiography are pointed out as advanced X-ray investigation methods. In the annex of X-ray images some of the described phenomena are shown in exemplary manner. (orig./MG)

  9. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... is commonly used to diagnose fractured bones or joint dislocation. Bone x-rays are the fastest and ... to view and assess bone fractures, injuries and joint abnormalities. This exam requires little to no special ...

  10. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... like a photographic negative). Today, most images are digital files that are stored electronically. These stored images ... and places the x-ray film holder or digital recording plate under the table in the area ...

  11. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... the patient lies. A drawer under the table holds the x-ray film or image recording plate . ... when feasible to protect from radiation. You must hold very still and may be asked to keep ...

  12. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... technologist, an individual specially trained to perform radiology examinations, positions the patient on the x-ray table ... bone is forming), for comparison purposes. When the examination is complete, you may be asked to wait ...

  13. Picosecond x-ray science

    International Nuclear Information System (INIS)

    The report discusses the exciting times for short pulse X-rays and the current users of the technology in the United States. Tracking nuclear motions with X-rays transcends scientific disciplines and includes Biology, Materials Science, Condensed Matter and Chemistry. 1 picosecond accesses many phenomena previously hidden at 100ps. Synchrotron advantage over laser plasma and LCLS is that it's easily tunable. There is a large and diverse user community of this technology that is growing rapidly. A working group is being formed to implement 'fast track' Phases 1 and 2 which includes tunable, polarized, monochromatic, focused X-rays; variable pulse length (1 to 100ps) and 1 kHz, 109 X-rays/s with 1% bandwidth. ERL would be a major advance for ultrafast time-resolved studies.

  14. X-ray microtomographic scanners

    Energy Technology Data Exchange (ETDEWEB)

    Syryamkin, V. I., E-mail: klestov-simon@mail.ru; Klestov, S. A., E-mail: klestov-simon@mail.ru [National Research Tomsk State University, Tomsk, 634050 (Russian Federation)

    2015-11-17

    The article studies the operating procedures of an X-ray microtomographic scanner and the module of reconstruction and analysis 3D-image of a test sample in particular. An algorithm for 3D-image reconstruction based on image shadow projections and mathematical methods of the processing are described. Chapter 1 describes the basic principles of X-ray tomography and general procedures of the device developed. Chapters 2 and 3 are devoted to the problem of resources saving by the system during the X-ray tomography procedure, which is achieved by preprocessing of the initial shadow projections. Preprocessing includes background noise removing from the images, which reduces the amount of shadow projections in general and increases the efficiency of the group shadow projections compression. In conclusion, the main applications of X-ray tomography are presented.

  15. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... or in bones. top of page How should I prepare? Most bone x-rays require no special ... to 10 minutes. top of page What will I experience during and after the procedure? A bone ...

  16. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... the body absorb the x-rays in varying degrees. Dense bone absorbs much of the radiation while ... is further reviewed by committees from the American College of Radiology (ACR) and the Radiological Society of ...

  17. Dental X-ray apparatus

    International Nuclear Information System (INIS)

    Intra-oral dental X-ray apparatus for panoramic dental radiography is described in detail. It comprises an electron gun having an elongated tubular target carrier extending into the patient's mouth. The carrier supports an inclined target for direction of an X-ray pattern towards a film positioned externally of the patient's mouth. Image definition is improved by a focusing anode which focuses the electron beam into a sharp spot (0.05 to 0.10 mm diameter) on the target. The potential on the focusing anode is adjustable to vary the size of the spot. An X-ray transmitting ceramic (oxides of Be, Al and Si) window is positioned adjacent to the front face of the target. The electron beam can be magnetically deflected to change the X-ray beam direction. (author)

  18. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... very controlled x-ray beams and dose control methods to minimize stray (scatter) radiation. This ensures that ... around joints, and in evaluating the hips of children with congenital problems. top of page This page ...

  19. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... can be taken to the patient in a hospital bed or the emergency room. The x-ray ... and international radiology protection organizations continually review and update the technique standards used by radiology professionals. Modern ...

  20. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... top of page What are the benefits vs. risks? Benefits Bone x-rays are the fastest and ... in the typical diagnostic range for this exam. Risks There is always a slight chance of cancer ...

  1. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... current x-ray images for diagnosis and disease management. top of page How is the procedure performed? ... in a known abnormality can be monitored over time. Follow-up examinations are sometimes the best way ...

  2. X-ray thickness gauge

    International Nuclear Information System (INIS)

    New design of X-ray gauge of rolled product thickness is suggested. It is supplied with self-compensation unit, removing the error, caused by changes of half-cycles of supply voltage of radiation source

  3. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... during x-ray examinations to use the lowest radiation dose possible while producing the best images for evaluation. National and international radiology protection organizations continually review and update the technique standards ...

  4. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... Leave jewelry at home and wear loose, comfortable clothing. You may be asked to wear a gown. ... appliances, eye glasses and any metal objects or clothing that might interfere with the x-ray images. ...

  5. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... a large photographic negative). Today, most images are digital files that are stored electronically. These stored images ... and places the x-ray film holder or digital recording plate under the table in the area ...

  6. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... current x-ray images for diagnosis and disease management. top of page How is the procedure performed? ... examination may also be necessary so that any change in a known abnormality can be monitored over ...

  7. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... replacement and fracture reductions. look for injury, infection, arthritis , abnormal bone growths and bony changes seen in ... injuries, including fractures, and joint abnormalities, such as arthritis. X-ray equipment is relatively inexpensive and widely ...

  8. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... the lowest radiation dose possible while producing the best images for evaluation. National and international radiology protection organizations continually review and update the technique standards used by radiology professionals. Modern x-ray systems ...

  9. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... pregnant. Many imaging tests are not performed during pregnancy so as not to expose the fetus to ... See the Safety page for more information about pregnancy and x-rays. top of page What does ...

  10. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... the patient in a hospital bed or the emergency room. The x-ray tube is connected to ... equipment is relatively inexpensive and widely available in emergency rooms, physician offices, ambulatory care centers, nursing homes ...

  11. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... the baby. See the Safety page for more information about pregnancy and x-rays. top of page ... procedure varies. See the Safety page for more information about radiation dose. Women should always inform their ...

  12. X-Ray Assembler Data

    Data.gov (United States)

    U.S. Department of Health & Human Services — Federal regulations require that an assembler who installs one or more certified components of a diagnostic x-ray system submit a report of assembly. This database...

  13. X-ray fluorescence holography

    CERN Document Server

    Hayashi, K; Takahashi, Y

    2003-01-01

    X-ray fluorescence holography (XFH) is a new structural analysis method of determining a 3D atomic arrangement around fluorescing atoms. We developed an XFH apparatus using advanced X-ray techniques and succeeded in obtaining high-quality hologram data. Furthermore, we introduced applications to the structural analysis of a thin film and the environment around dopants and, discussed the quantitative analysis of local lattice distortion. (author)

  14. Accelerator x-ray sources

    CERN Document Server

    Talman, Richard

    2007-01-01

    This first book to cover in-depth the generation of x-rays in particle accelerators focuses on electron beams produced by means of the novel Energy Recovery Linac (ERL) technology. The resulting highly brilliant x-rays are at the centre of this monograph, which continues where other books on the market stop. Written primarily for general, high energy and radiation physicists, the systematic treatment adopted by the work makes it equally suitable as an advanced textbook for young researchers.

  15. Electromechanical x-ray generator

    Energy Technology Data Exchange (ETDEWEB)

    Watson, Scott A; Platts, David; Sorensen, Eric B

    2016-05-03

    An electro-mechanical x-ray generator configured to obtain high-energy operation with favorable energy-weight scaling. The electro-mechanical x-ray generator may include a pair of capacitor plates. The capacitor plates may be charged to a predefined voltage and may be separated to generate higher voltages on the order of hundreds of kV in the AK gap. The high voltage may be generated in a vacuum tube.

  16. Insights from soft X-rays

    DEFF Research Database (Denmark)

    Raaf, Jennifer; Issinger, Olaf-Georg; Niefind, Karsten

    2008-01-01

    The diffraction pattern of a protein crystal is normally a product of the interference of electromagnetic waves scattered by electrons of the crystalline sample. The diffraction pattern undergoes systematic changes in case additionally X-ray absorption occurs, meaning if the wavelength of the...... particularly useful application of this phenomenon is the experimental detection of the sub-structures of the anomalous scatterers in protein crystals. We demonstrate this here with a crystal of a C-terminally truncated variant of human CK2alpha to which two molecules of the inhibitor 5,6-dichloro-1-beta...

  17. X-ray laser; Roentgenlaser

    Energy Technology Data Exchange (ETDEWEB)

    Samuelsen, Emil J.; Breiby, Dag W.

    2009-07-01

    X-ray is among the most important research tools today, and has given priceless contributions to all disciplines within the natural sciences. State of the art in this field is called XFEL, X-ray Free Electron Laser, which may be 10 thousand million times stronger than the x-rays at the European Synchrotron Radiation Facility in Grenoble. In addition XFEL has properties that allow the study of processes which previously would have been impossible. Of special interest are depictions on atomic- and molecular level by the use of x-ray holographic methods, and being able to study chemical reactions in nature's own timescale, the femtosecond. Conclusion: The construction of x-ray lasers is a natural development in a scientific field which has an enormous influence on the surrounding society. While the discovery of x-ray was an important breakthrough in itself, new applications appear one after the other: Medical depiction, dissemination, diffraction, DNA and protein structures, synchrotron radiation and tomography. There is reason to believe that XFEL implies a technological leap as big as the synchrotrons some decades ago. As we are now talking about studies of femtosecond and direct depiction of chemical reactions, it is obvious that we are dealing with a revolution to come, with extensive consequences, both scientifically and culturally. (EW)

  18. X-ray diagnostic apparatus

    International Nuclear Information System (INIS)

    A falling load type X-ray diagnostic apparatus comprises a low voltage power source, AC-DC converting means connected to the low voltage power source so as to apply a rectified low DC voltage, chopping means connected to the AC-DC converting means and chopping said DC voltage into a low AC voltage, high voltage applying means for transforming said low AC voltage into a high AC voltage, said high AC voltage being applied as a tube voltage to an X-ray tube from which X-rays are irradiated toward an object to be examined, means for controlling a filament heating power of the X-ray tube, programming means for supplying a control signal to said filament heating control means so as to reduce the emission current of said X-ray tube during the irradiation, and chopper control means for controlling the chopping ratio of said chopping means by evaluating said rectified DC voltage with a preset tube voltage generated in said programming means, said programming means compensating said tube voltage by receiving said control signal in such a manner that said tube voltage is maintained substantially constant during the irradiation by varying said preset tube voltage so as to control the chopping ratio based upon the reduction of the filament heating power for the X-ray tube

  19. Low energy (soft) x rays

    International Nuclear Information System (INIS)

    Dosimetry of low-energy (soft) X rays produced by the SOFTEX Model CMBW-2 was performed using Nuclear Associates Type 30 - 330 PTW, Exradin Type A2, and Shonka-Wyckoff ionization chambers with a Keithley Model 602 electrometer. Thermoluminescent (BeO chip) dosimeters were used with a Harshaw Detector 2000-A and Picoammeter-B readout system. Beam quality measurements were made using aluminum absorbers; exposure rates were assessed by the current of the X-ray tube and by exposure times. Dose distributions were established, and the average factors for non-uniformity were calculated. The means of obtaining accurate absorbed and exposed doses using these methods are discussed. Survival of V79 cells was assessed by irradiating them with soft X rays, 200 kVp X rays, and 60Co gamma rays. The relative biological effectiveness (RBE) values for soft X rays with 0, 0.2, 0.7 mm added thicknesses of aluminum were 1.6, which were compared to 60Co. The RBE of 200 kVp X rays relative to 60Co was 1.3. Results of this study are available for reference in future RERF studies of cell survival. (author)

  20. Tokamak x ray diagnostic instrumentation

    International Nuclear Information System (INIS)

    Three classes of x-ray diagnostic instruments enable measurement of a variety of tokamak physics parameters from different features of the x-ray emission spectrum. (1) The soft x-ray (1 to 50 keV) pulse-height-analysis (PHA) diagnostic measures impurity concentrations from characteristic line intensities and the continuum enhancement, and measures the electron temperature from the continuum slope. (2) The Bragg x-ray crystal spectrometer (XCS) measures the ion temperature and neutral-beam-induced toroidal rotation velocity from the Doppler broadening and wavelength shift, respectively, of spectral lines of medium-Z impurity ions. Impurity charge state distributions, precise wavelengths, and inner-shell excitation and recombination rates can also be studied. X rays are diffracted and focused by a bent crystal onto a position-sensitive detector. The spectral resolving power E/ΔE is greater than 104 and time resolution is 10 ms. (3) The x-ray imaging system (XIS) measures the spatial structure of rapid fluctuations (0.1 to 100 kHZ) providing information on MHD phenomena, impurity transport rates, toroidal rotation velocity, plasma position, and the electron temperature profile. It uses an array of silicon surface-barrier diodes which view different chords of the plasma through a common slot aperture and operate in current (as opposed to counting) mode. The effectiveness of shields to protect detectors from fusion-neutron radiation effects has been studied both theoretically and experimentally

  1. The 300 kpc Long X-ray Jet in PKS 1127-145, z=1.18 Quasar: Constraining X-ray Emission Models

    CERN Document Server

    Siemiginowska, A; Cheung, C C; Harris, D E; Sikora, M; Aldcroft, T L; Bechtold, J; Siemiginowska, Aneta; Stawarz, Lukasz; Sikora, Marek; Aldcroft, Thomas L.; Bechtold, Jill

    2006-01-01

    We present a ~100 ksec Chandra X-ray observation and new VLA radio data of the large scale, 300 kpc long X-ray jet in PKS1127-145, a radio loud quasar at redshift z=1.18. With this deep X-ray observation we now clearly discern the complex X-ray jet morphology and see substructure within the knots. The X-ray and radio jet intensity profiles are seen to be strikingly different with the radio emission peaking strongly at the two outer knots while the X-ray emission is strongest in the inner jet region. The jet X-ray surface brightness gradually decreases by an order of magnitude going out from the core. The new X-ray data contain sufficient counts to do spectral analysis of the key jet features. The X-ray energy index of the inner jet is relatively flat with alpha_X = 0.66 +/-0.15 and steep in the outer jet with alpha_X = 1.0 +/-0.2. We discuss the constraints implied by the new data on the X-ray emission models and conclude that ``one-zone'' models fail and at least a two component model is needed to explain th...

  2. Center for X-Ray Optics, 1992

    International Nuclear Information System (INIS)

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

  3. X-ray instrumentation for SR beamlines

    Energy Technology Data Exchange (ETDEWEB)

    Kovalchuk, M.V.; Shilin, Yu.N.; Zheludeva, S.I. E-mail: zheludeva@ns.crys.ras.ru; Aleshko-Ozhevsky, O.P.; Arutynyan, E.H.; Kheiker, D.M.; Kreines, A.Ya.; Lider, V.V.; Pashaev, E.M.; Shilina, N.Yu.; Shishkov, V.A

    2000-06-21

    The main possibilities and parameters of experimental X-ray stations are presented: 'Protein crystallography', 'X-ray structure analysis', 'High-precision X-ray optics', 'X-ray crystallography and material science', 'X-ray topography', 'Photoelectron X-ray standing wave' that are being installed at Kurchatov SR source by A.V. Shubnikov Institute of Crystallography.

  4. Small-angle x-ray scattering studies of calmodulin mutants with deletions in the linker region of the central helix indicate that the linker region retains a predominantly. alpha. -helical conformation

    Energy Technology Data Exchange (ETDEWEB)

    Kataoka, Mikio; Engelman, D.M. (Yale Univ., New Haven, CT (USA)); Head, J.F. (Boston Univ., MA (USA)); Persechini, A.; Kretsinger, R.H. (Univ. of Virginia, Charlottesville (USA))

    1991-02-05

    Two mutant forms of calmodulin were examined by small-angle X-ray scattering in solution and compared with the wild-type protein. Each mutant has deletions in the linker region of the central helix: one lacks residues Glu-83 and Glu-84 (Des2) and the other lacks residues Ser-81 through Glu-84 (Des4). The deletions change both the radii of gyration and the maximum dimensions of the molecules. In the presence of Ca{sup 2+}, the observed radii of gyration are 22.4 {angstrom} for wild-type bacterially expressed calmodulin, 19.5 {angstrom} for Des2 calmodulin, and 20.3 {angstrom} for Des4 calmodulin. A reduction in the radius of gyration by 1-2 {angstrom} on removal of calcium, previously observed in the native protein, was also found in the wild type and the Des4 mutant; however, no significant size change was observed in the Des2 mutant. The large calcium-dependent conformational change in calmodulin induced by the binding of melittin was observed in all the bacterially expressed proteins. Each protein appears to undergo a transition from a dumbbell shape to a more globular conformation on binding melittin in the presence of calcium, although quantitatively the changes in the wild-type and Des4 proteins greatly exceed those in Des2. Modeling shows that the structural properties of the deletion mutants are well described by modifications of an {alpha} helix in the central linker region of the molecule. Thus, the structure of the linker region is stable enough to maintain the average orientation and separation of the lobes yet flexible enough to permit the lobes to approach each other upon binding a peptide.

  5. Analisis Klaster K-Means dari Data Luas Grup Sunspot dan Data Grup Sunspot Klasifikasi Mc.Intosh yang membangkitkan Flare Soft X-Ray dan H-alpha

    Directory of Open Access Journals (Sweden)

    Siti Jumaroh

    2015-12-01

    Full Text Available Analisis klaster merupakan teknik interpendensi yang mengelompokkan suatu objek berdasarkan kemiripan dan kedekatan jarak antar objek. Pengelompokan objek dengan jumlah banyak membutuhkan waktu yang lama. Salah satu analisis klaster yang dapat digunakan dalam situasi ini adalah analisis klaster non hierarki, yaitu K-means. Pada artikel ini mengelompokkan data luas grup sunspot dan data grup sunspot klasifikasi Mc.Intosh yang membangkitkan flare soft X-Ray dan Hα. Untuk mengetahui luas grup sunspot dan grup sunspot klasifikasi Mc.Intosh yang berpeluang membangkitkan flare soft X-Ray dan Hα dengan intensitas ledakan yang tinggi dan rendah. Berdasarkan hasil analisis, diperoleh dua klaster yaitu klaster pertama yang tergolong mampu membangkitkan flare Soft X-Ray dan Hα dengan intensitas yang tinggi. Sedangkan klaster kedua yang tergolong mampu membangkitkan flare Soft X-Ray dan Hα dengan intensitas yang rendah

  6. X-rays and some applications

    International Nuclear Information System (INIS)

    This book is one of the specialized books issued by the Arab Atomic Energy Agency about the key technologies of interest to Arab researchers . The book contains 10 chapters as follows: the nature of X-ray, methods of production and measurement of X-rays, X-ray and materials, X-ray crystallography, X-ray and chemistry, X-ray and physics, biological effects of X-ray, radiography in the field of medicine and biology, X-ray in the field of industry, other applications in agriculture, imaging artifacts and paintings and geology.

  7. X-ray fluorescence cross sections for K and L x rays of the elements

    Energy Technology Data Exchange (ETDEWEB)

    Krause, M.O.; Nestor, C.W. Jr.; Sparks, C.J. Jr.; Ricci, E.

    1978-06-01

    X-ray fluorescence cross sections are calculated for the major x rays of the K series 5 less than or equal to Z less than or equal to 101, and the three L series 12 less than or equal to Z less than or equal to 101 in the energy range 1 to 200 keV. This calculation uses Scofield's theoretical partical photoionization cross sections, Krause's evaluation of fluorescence and Coster-Kronig yields, and Scofield's theoretical radiative rates. Values are presented in table and graph format, and an estimate of their accuracy is made. The following x rays are considered: K..cap alpha../sub 1/, K..cap alpha../sub 1/,/sub 2/, K..beta../sub 1/, K..beta../sub 1/,/sub 3/, L..cap alpha../sub 1/, L..cap alpha../sub 1/,/sub 2/, L..beta../sub 1/, L..beta../sub 2/,/sub 15/, L..beta../sub 3/, Ll, L..gamma../sub 1/, L..gamma../sub 4/, and L/sub 1/ ..-->.. L/sub 2/,/sub 3/. For use in x-ray fluorescence analysis, K..cap alpha.. and L..cap alpha.. fluorescence cross sections are presented at specific energies: TiK identical with 4.55 keV, CrK identical with 5.46 keV, CoK identical with 7.00 keV, CuK identical with 8.13 keV, MoK..cap alpha.. identical with 17.44 keV, AgK identical with 22.5 keV, DyK identical with 47.0 keV, and /sup 241/Am identical with 59.54 keV. Supplementary material includes fluorescence and Coster--Kronig yields, fractional radiative rates, fractional fluorescence yields, total L-shell fluorescence cross sections, fluorescence and Coster-Kronig yields in condensed matter, effective fluorescence yields, average L-shell fluorescence yield, L-subshell photoionization cross section ratios, and conversion factors from barns per atom to square centimeters per gram.

  8. X-ray Echo Spectroscopy

    Science.gov (United States)

    Shvyd'ko, Yuri

    2016-02-01

    X-ray echo spectroscopy, a counterpart of neutron spin echo, is being introduced here to overcome limitations in spectral resolution and weak signals of the traditional inelastic x-ray scattering (IXS) probes. An image of a pointlike x-ray source is defocused by a dispersing system comprised of asymmetrically cut specially arranged Bragg diffracting crystals. The defocused image is refocused into a point (echo) in a time-reversal dispersing system. If the defocused beam is inelastically scattered from a sample, the echo signal acquires a spatial distribution, which is a map of the inelastic scattering spectrum. The spectral resolution of the echo spectroscopy does not rely on the monochromaticity of the x rays, ensuring strong signals along with a very high spectral resolution. Particular schemes of x-ray echo spectrometers for 0.1-0.02 meV ultrahigh-resolution IXS applications (resolving power >108 ) with broadband ≃5 - 13 meV dispersing systems are introduced featuring more than 103 signal enhancement. The technique is general, applicable in different photon frequency domains.

  9. X-ray echo spectroscopy

    CERN Document Server

    Shvyd'ko, Yuri

    2015-01-01

    X-ray echo spectroscopy, a counterpart of neutron spin-echo, is being introduced here to overcome limitations in spectral resolution and weak signals of the traditional inelastic x-ray scattering (IXS) probes. An image of a point-like x-ray source is defocused by a dispersing system comprised of asymmetrically cut specially arranged Bragg diffracting crystals. The defocused image is refocused into a point (echo) in a time-reversal dispersing system. If the defocused beam is inelastically scattered from a sample, the echo signal acquires a spatial distribution, which is a map of the inelastic scattering spectrum. The spectral resolution of the echo spectroscopy does not rely on the monochromaticity of the x-rays, ensuring strong signals along with a very high spectral resolution. Particular schemes of x-ray echo spectrometers for 0.1--0.02-meV ultra-high-resolution IXS applications (resolving power $> 10^8$) with broadband $\\simeq$~5--13~meV dispersing systems are introduced featuring more than $10^3$ signal e...

  10. X-ray sensitivity measurements on CVD diamond film detectors

    International Nuclear Information System (INIS)

    Microwave chemical vapor deposited (CVD) diamond films have been used to fabricate radiation detectors. The polycrystalline diamond films have a resistivity of 1012 ohm.cm and carrier mobility and lifetime of about 280 cm2/V.s and 530 ps. The detector response to laser pulses (355, 532 and 1064 nm), X-ray flux (15-50 keV) and alpha particles (241Am, 5.49 MeV) has been investigated. The response speed of the detector is in the 100 ps range. A sensitivity of about 3 x 10-10 A/V.Gy.s was measured under 50 keV X-ray flux. The detector current response to X-ray flux is almost linear. It is also shown that CVD diamond detectors can be used for alpha particle counting. (authors). 9 figs., 25 refs

  11. Dental X-ray apparatus

    International Nuclear Information System (INIS)

    Intra-oral X-ray apparatus which reduces the number of exposures necessary to obtain panoramic dental radiographs is described in detail. It comprises an electron gun, a tubular target carrier projecting from the gun along the beam axis and carrying at its distal end a target surrounded by a shield of X-ray opaque material. This shield extends forward and laterally of the target and has surfaces which define a wedge or cone-shaped radiation pattern delimited vertically by the root tips of the patient's teeth. A film holder is located externally of the patient's mouth. A disposable member can fit on the target carrier to depress the patient's tongue out of the radiation pattern and to further shield the roof of the mouth. The electron beam can be magnetically deflected to change the X-ray beam direction. (author)

  12. Extragalactic X-ray sources

    International Nuclear Information System (INIS)

    About 40% of the X-ray sources in the third UHURU catalogue are extragalactic. One, SMC X-1 has been identified with a binary star in the lesser Magellanic Cloud, while five sources, three probably binary stars, have been found in the greater Magellanic Cloud. X-ray sources in normal galaxies (M31), radiogalaxies (NGC5128), Seyfert galaxies (NGC4151), quasars (3C273) and galaxy clusters (Virgo X-1 and Perseus X-1) are briefly discussed. The most probable explanation for the origin of X-ray emissions from galaxy clusters appears at present to be that the cluster is filled with a thin, very hot gas which emits X-radiation by thermal bremsstrahlung. The main alternative is a socalled inverse Compton effect. (JIW)

  13. X-ray imaging: Perovskites target X-ray detection

    Science.gov (United States)

    Heiss, Wolfgang; Brabec, Christoph

    2016-05-01

    Single crystals of perovskites are currently of interest to help fathom fundamental physical parameters limiting the performance of perovskite-based polycrystalline solar cells. Now, such perovskites offer a technology platform for optoelectronic devices, such as cheap and sensitive X-ray detectors.

  14. Spectral and imaging characterization of tabletop x-ray lasers

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, J; Faenov, A Ya; Pikuz, T A; Osterheld, A; Moon, S J; Fournier, K B; Nilsen, J; Skobelev, I Yu; Magunov, A I; Shlyaptsev, V N

    2000-12-01

    We have performed L-shell spectroscopy and one-dimensional (1-D) imaging of a line focus plasma from a laser-heated Fe polished slab using the tabletop COMET laser system at the Lawrence Livermore National Laboratory. These plasmas are used to generate a Ne-like Fe transient gain x-ray laser that is recorded simultaneously. A spherically-curved crystal spectrometer gives high resolution x-ray spectra of the n = 3-2 and n = 4-2 resonance lines with 1-D spatial resolution along the line focus. Spectra are presented for different laser pulse conditions. In addition, a variety of x-ray imaging techniques are described. We discuss imaging results from a double-slit x-ray camera with a spherically-curved crystal spectrometer. We show a high resolution Fe K-{alpha} spectrum from the x-ray laser target that indicates the presence of hot electrons in the x-ray laser plasma.

  15. X-ray hot plasma diagnostics

    International Nuclear Information System (INIS)

    X-ray plasma emission study is powerful diagnostic tool of hot plasmas. In this review article the main techniques of X-ray plasma emission measurement are shortly presented: X-ray spectrometry using absorbent filters, crystal and grating spectrometers, imaging techniques using pinhole cameras, X-ray microscopes and Fresnel zone plate cameras, X-ray plasma emission calorimetry. Advances in these techniques with examples for different hot plasma devices are also presentes. (author)

  16. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... exam requires little to no special preparation. Tell your doctor and the technologist if there is any possibility you are pregnant. Leave jewelry at home and wear loose, comfortable clothing. You may be asked to wear a gown. What is Bone X-ray (Radiography)? What are some ...

  17. X-ray image converters

    International Nuclear Information System (INIS)

    The invention pertains to rare earth phosphor admixtures utilizing thulium-activated lanthanum or gadolinium oxyhalide phosphor material. These materials increase the relative speed and resolution of an X-ray image compared with conventional phosphors as well as reducing the still serious crossover problem now experienced with conventional phosphors. (Auth.)

  18. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... Images related to X-ray (Radiography) - Bone About this Site RadiologyInfo.org is produced by: Please note ... you can search the ACR-accredited facilities database . This website does not provide cost information. The costs ...

  19. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... Safety En Español More Info Images/Videos News Physician Resources Professions Site Index A-Z X-ray ( ... are the fastest and easiest way for your doctor to view and assess bone fractures, injuries and ...

  20. X-Ray Diffractive Optics

    Science.gov (United States)

    Dennis, Brian; Li, Mary; Skinner, Gerald

    2013-01-01

    X-ray optics were fabricated with the capability of imaging solar x-ray sources with better than 0.1 arcsecond angular resolution, over an order of magnitude finer than is currently possible. Such images would provide a new window into the little-understood energy release and particle acceleration regions in solar flares. They constitute one of the most promising ways to probe these regions in the solar atmosphere with the sensitivity and angular resolution needed to better understand the physical processes involved. A circular slit structure with widths as fine as 0.85 micron etched in a silicon wafer 8 microns thick forms a phase zone plate version of a Fresnel lens capable of focusing approx. =.6 keV x-rays. The focal length of the 3-cm diameter lenses is 100 microns, and the angular resolution capability is better than 0.1 arcsecond. Such phase zone plates were fabricated in Goddard fs Detector Development Lab. (DDL) and tested at the Goddard 600-microns x-ray test facility. The test data verified that the desired angular resolution and throughput efficiency were achieved.

  1. X-ray diagnostic equipment

    International Nuclear Information System (INIS)

    Lateral and orbital scanning movements can be carried out with the equipment. The assessment is carried out by a computer. Differences in sensitivity of the detectors can be compensated for by displacement of the electron beam of the X-ray tube compared to the anti-cathode or by bending of the electron beam by electromagnetic coils. (RW)

  2. X-ray fluorescence spectrometry

    International Nuclear Information System (INIS)

    The seventh edition of Philips' Review of Literature on x-ray fluorescence spectrometry starts with a list of conference proceedings on the subject, organised by the Philips organisation at regular intervals in various European countries. It is followed by a list of bulletins. The bibliography is subdivided according to spectra, equipment, applications and absorption analysis

  3. X-ray film processing

    International Nuclear Information System (INIS)

    X-ray films have to be highly sensitive, for radiation protection reasons. The films used in radiology are coated on both sides with a photosensitive emulsion. This applies to all dental films. Their properties and the development of the different exposed films are explained. (DG)

  4. X-ray backscatter imaging

    Science.gov (United States)

    Dinca, Dan-Cristian; Schubert, Jeffrey R.; Callerame, J.

    2008-04-01

    In contrast to transmission X-ray imaging systems where inspected objects must pass between source and detector, Compton backscatter imaging allows both the illuminating source as well as the X-ray detector to be on the same side of the target object, enabling the inspection to occur rapidly and in a wide variety of space-constrained situations. A Compton backscatter image is similar to a photograph of the contents of a closed container, taken through the container walls, and highlights low atomic number materials such as explosives, drugs, and alcohol, which appear as especially bright objects by virtue of their scattering characteristics. Techniques for producing X-ray images based on Compton scattering will be discussed, along with examples of how these systems are used for both novel security applications and for the detection of contraband materials at ports and borders. Differences between transmission and backscatter images will also be highlighted. In addition, tradeoffs between Compton backscatter image quality and scan speed, effective penetration, and X-ray source specifications will be discussed.

  5. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos News Physician Resources Professions Site Index A-Z X-ray (Radiography) - Bone ...

  6. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... top of page What are the benefits vs. risks? Benefits Bone x-rays are the fastest and easiest ... cancer from excessive exposure to radiation. However, the benefit of an accurate diagnosis far outweighs the risk. The effective radiation dose for this procedure varies. ...

  7. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... over time. top of page What are the benefits vs. risks? Benefits Bone x-rays are the fastest and easiest ... cancer from excessive exposure to radiation. However, the benefit of an accurate diagnosis far outweighs the risk. ...

  8. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... over time. top of page What are the benefits vs. risks? Benefits Bone x-rays are the fastest and easiest ... evaluation. National and international radiology protection organizations continually review and update the technique standards used by radiology ...

  9. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... current x-ray images for diagnosis and disease management. top of page How is the procedure performed? ... benefit of an accurate diagnosis far outweighs the risk. The effective ... more information about radiation dose. Women should always inform their ...

  10. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available Toggle navigation Test/Treatment Patient Type Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos ... to current x-ray images for diagnosis and disease management. top of page How is the procedure ...

  11. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... for more information about pregnancy and x-rays. A Word About Minimizing Radiation Exposure Special care is ... encourage linking to this site. × Recommend RadiologyInfo to a friend Send to (friend's e-mail address): From ( ...

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

    OpenAIRE

    de Groot, F. M. F.

    2001-01-01

    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 process. Section II discusses 1s X-ray absorption, i.e., the K edges, and section III deals with 2p X-ray absorption, the L edges. X-ray emission is discussed in, respectively, the L edges. X-ray emis...

  13. Accuracy in x-ray reflectivity analysis

    Energy Technology Data Exchange (ETDEWEB)

    Tiilikainen, J; Tilli, J-M; Bosund, V; Mattila, M; Hakkarainen, T; Sormunen, J; Lipsanen, H [Micro and Nanosciences Laboratory, Helsinki University of Technology, Micronova, PO Box 3500, FI-02015 TKK (Finland)

    2007-12-07

    The influence of Poisson noise on the accuracy of x-ray reflectivity analysis is studied with an aluminium oxide (AlO) layer on silicon. A null hypothesis which argues that other than the exact solution gives the best fitness is examined with a statistical p-value test using a significance level of {alpha} = 0.01. Simulations are performed for a fit instead of a measurement since the exact error caused by noise cannot be determined from the measurement. The p-value is studied by comparing trial curves to 1000 'measurements', each of them including synthetic Poisson noise. Confidence limits for the parameters of Parratt's formalism and the Nevot-Croce approximation are determined in (mass density, surface roughness) (thickness, surface roughness) and (thickness, mass density) planes. The most significant result is that the thickness determination accuracy of AlO is approximately {+-}0.09 nm but the accuracy is better for materials having higher mass density. It is also shown that the accuracy of mass density determination can be significantly improved using a suitably designed fitness measure. Although the power of the presented method is demonstrated only in one case, it can be used in any parameter region for a plethora of single layer systems to find the lower limit of the error made in x-ray reflectivity analysis.

  14. Energy response of graphite-mixed magnesium borate TLDs to low energy x-rays

    DEFF Research Database (Denmark)

    Pelliccioni, M.; Prokic, M.; Esposito, A.; Nuccetelli, C.; Christensen, P.

    1991-01-01

    energy response to very low energy x-rays are presented and evidence of agreement between experimental and calculated conversion coefficient H'(0.07, alpha = 0-degrees)/Ka is also shown. A monochromatized x-ray beam from a synchrotron radiation source in the energy range from 3 to 12 keV has been...

  15. X-Ray Emission from M32: X-Ray Binaries or a micro-AGN?

    OpenAIRE

    Eskridge, Paul B.; White III, Raymond E.; Davis, David S.

    1996-01-01

    We have analysed archival {\\it ROSAT} PSPC data for M32 in order to study the x-ray emission from this nearest elliptical galaxy. We fit spectra from three long exposures with Raymond-Smith, thermal bremsstrahlung, and power-law models. All models give excellent fits. The thermal fits have kT$\\approx$4 keV, the Raymond-Smith iron abundance is $0.4^{+0.7}_{-0.3}$ Solar, the power-law fit has $\\alpha$=1.6$\\pm$0.1, and all fits have $N_H$ consistent with the Galactic column. The source is center...

  16. Center for X-Ray Optics, 1986

    International Nuclear Information System (INIS)

    The Center for X-Ray Optics has made substantial progress during the past year on the development of very high resolution x-ray technologies, the generation of coherent radiation at x-ray wavelengths, and, based on these new developments, had embarked on several scientific investigations that would not otherwise have been possible. The investigations covered in this report are topics on x-ray sources, x-ray imaging and applications, soft x-ray spectroscopy, synchrotron radiation, advanced light source and magnet structures for undulators and wigglers

  17. Digital x-ray imaging

    International Nuclear Information System (INIS)

    Digital radiography is progressively replacing conventional (film-based) radiographic techniques promising consistently high levels of image quality, more effective use of radiation and more efficient work practices. At the same time its introduction poses new challenges to those physical scientists who design radiological imaging systems and those who provide scientific/technical support to a clinical radiology service. In this review scientific aspects of those digital x-ray imaging systems which are proving most successful are described. Physical measurement techniques developed to evaluate the imaging performance and radiation dose efficiency of clinical digital radiography systems are outlined. Finally, directions in which digital x-ray imaging technology may evolve in the coming decade are discussed. (author)

  18. The 300 Kpc Long X-Ray Jet in PKS 1127-145, Z=1.18 Quasar: Constraining X-Ray Emission Models

    Energy Technology Data Exchange (ETDEWEB)

    Siemiginowska, Aneta; /Harvard-Smithsonian Ctr. Astrophys.; Stawarz, Lukasz; /Heidelberg Observ. /Jagiellonian U., Astron. Observ. /KIPAC, Menlo Park; Cheung, C.C.; /KIPAC,; Harris, D.E.; /Harvard-Smithsonian Ctr. Astrophys.; Sikora, Marek; /Warsaw, Copernicus Astron. Ctr.; Aldcroft, Thomas L.; /Harvard-Smithsonian Ctr. Astrophys.; Bechtold,; /Arizona U., Astron. Dept. - Steward Observ.

    2006-11-20

    We present a {approx} 100 ksec Chandra X-ray observation and new VLA radio data of the large scale, 300 kpc long X-ray jet in PKS 1127-145, a radio loud quasar at redshift z=1.18. With this deep X-ray observation we now clearly discern the complex X-ray jet morphology and see substructure within the knots. The X-ray and radio jet intensity profiles are seen to be strikingly different with the radio emission peaking strongly at the two outer knots while the X-ray emission is strongest in the inner jet region. The jet X-ray surface brightness gradually decreases by an order of magnitude going out from the core. The new X-ray data contain sufficient counts to do spectral analysis of the key jet features. The X-ray energy index of the inner jet is relatively flat with {alpha}{sub x} = 0.66 {+-} 0.15 and steep in the outer jet with {alpha}{sub x} = 1.0 {+-} 0.2. We discuss the constraints implied by the new data on the X-ray emission models and conclude that ''one-zone'' models fail and at least a two component model is needed to explain the jet's broad-band emission. We propose that the X-ray emission originates in the jet proper while the bulk of the radio emission comes from a surrounding jet sheath. We also consider intermittent jet activity as a possible cause of the observed jet morphology.

  19. Soft x-ray tomoholography

    International Nuclear Information System (INIS)

    We demonstrate an x-ray imaging method that combines Fourier transform holography with tomography (‘tomoholography’) for three-dimensional (3D) microscopic imaging. A 3D image of a diatom shell with a spatial resolution of 140 nm is presented. The experiment is realized by using a small gold sphere as the reference wave source for holographic imaging. This setup allows us to rotate the sample and to collect a number of 2D projections for tomography. (paper)

  20. Soft x-ray tomoholography

    OpenAIRE

    Guehrs, E.; Stadler, A.M.; Flewett, S.; Frömmel, S.; Geilhufe, J.; Pfau, B; Rander, T.; Schaffert, S.; Büldt, G; Eisebitt, S.

    2012-01-01

    We demonstrate an x-ray imaging method that combines Fourier transform holography with tomography ('tomoholography') for three-dimensional (3D) microscopic imaging. A 3D image of a diatom shell with a spatial resolution of 140 nm is presented. The experiment is realized by using a small gold sphere as the reference wave source for holographic imaging. This setup allows us to rotate the sample and to collect a number of 2D projections for tomography.

  1. X-ray tube arrangements

    International Nuclear Information System (INIS)

    A technique for ensuring the rapid correction of both amplitude and offset errors in the deflectional movement of an electron beam along an X-ray emissive target is described. The movement is monitored at at least two positions during a sweep and differences, between the two movements and a desired movement, at these positions are combined in different proportions to produce a corrective servo signal. Such arrangements find application, for example, in computerised tomographic scanners. (author)

  2. Solid-Density Plasma characterization with X-ray scattering on the 200-J Janus Laser

    Energy Technology Data Exchange (ETDEWEB)

    Neumayer, P B; Gregori, G; Ravasio, A; Price, D; Bastea, M; Landen, O L; Glenzer, S H

    2006-04-25

    We present collective x-ray scattering (CXS) measurements using a Chlorine He-{alpha} x-ray source pumped with less than 200 J of laser energy. The experimental scattering spectra show plasmon resonances from shocked samples. These experiments use only 10{sup 12} x-ray photons at the sample of which 10{sup -5} have been scattered and detected with a highly efficient curved crystal spectrometer. Our results demonstrate that x-ray scattering is a viable technique on smaller laser facilities making CXS measurements accessible to a broad scientific community.

  3. X-ray-powered macronovae

    CERN Document Server

    Kisaka, Shota; Nakar, Ehud

    2015-01-01

    A macronova (or kilonova) was observed as an infrared excess several days after short gamma-ray burst, GRB 130603B. Although the $r$-process radioactivity is widely discussed as an energy source, it requires huge mass of ejecta from a neutron star (NS) binary merger. We propose that the X-ray excess simultaneously observed with the infrared excess can naturally heat the ejecta, leading to the thermal re-emission as observed in infrared. This X-ray-powered model explains both the X-ray and infrared excesses with a single energy source by the central engine like a black hole, and allows for broader parameter region, in particular smaller ejecta mass $\\sim10^{-3}-10^{-2}M_{\\odot}$ with iron mixed as suggested by general relativistic simulations for typical NS-NS mergers, than the previous models. We also discuss the other macronova candidates in GRB 060614 and GRB 080503, and implications for the search of electromagnetic counterparts to gravitational waves.

  4. X-Ray Crystallography Reagent

    Science.gov (United States)

    Morrison, Dennis R. (Inventor); Mosier, Benjamin (Inventor)

    2003-01-01

    Microcapsules prepared by encapsulating an aqueous solution of a protein, drug or other bioactive substance inside a semi-permeable membrane by are disclosed. The microcapsules are formed by interfacial coacervation under conditions where the shear forces are limited to 0-100 dynes per square centimeter at the interface. By placing the microcapsules in a high osmotic dewatering solution. the protein solution is gradually made saturated and then supersaturated. and the controlled nucleation and crystallization of the protein is achieved. The crystal-filled microcapsules prepared by this method can be conveniently harvested and stored while keeping the encapsulated crystals in essentially pristine condition due to the rugged. protective membrane. Because the membrane components themselves are x-ray transparent, large crystal-containing microcapsules can be individually selected, mounted in x-ray capillary tubes and subjected to high energy x-ray diffraction studies to determine the 3-D smucture of the protein molecules. Certain embodiments of the microcapsules of the invention have composite polymeric outer membranes which are somewhat elastic, water insoluble, permeable only to water, salts, and low molecular weight molecules and are structurally stable in fluid shear forces typically encountered in the human vascular system.

  5. X-Ray-powered Macronovae

    Science.gov (United States)

    Kisaka, Shota; Ioka, Kunihito; Nakar, Ehud

    2016-02-01

    A macronova (or kilonova) was observed as an infrared excess several days after the short gamma-ray burst GRB 130603B. Although the r-process radioactivity is widely discussed as an energy source, it requires a huge mass of ejecta from a neutron star (NS) binary merger. We propose a new model in which the X-ray excess gives rise to the simultaneously observed infrared excess via thermal re-emission, and explore what constraints this would place on the mass and velocity of the ejecta. This X-ray-powered model explains both the X-ray and infrared excesses with a single energy source such as the central engine like a black hole, and allows for a broader parameter region than the previous models, in particular a smaller ejecta mass ˜ {10}-3{--}{10}-2{M}⊙ and higher iron abundance mixed as suggested by general relativistic simulations for typical NS-NS mergers. We also discuss the other macronova candidates in GRB 060614 and GRB 080503, and the implications for the search of electromagnetic counterparts to gravitational waves.

  6. Morphological changes of mouse ovary by X-ray irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Chul Ho; Yoon, Surk Hwan [Dongnam Health College, Suwon (Korea, Republic of); Choi, Jong Woon [Daejeon Health Science College, Daejeon (Korea, Republic of)

    2007-12-15

    decreased. The finding that the reaction of granular cells around folliculus ovary was stronger than that near follicular membrane indicates that what was damaged first by X-ray was the cells near folliculus ovary and follicular antrum. The reactivity of inhibin-{alpha} showed difference according to the growing stage of folliculus ovary: inhibin-{alpha} showed the most strong reaction in mature folliculus ovary with follicular antrum. There was strong reaction in granular cells around follicular membrane but inhibin-{alpha} did not occur at all in theca cells comprising follicular membrane. Inhibin-{alpha} in ovary tissue exposed to 400 cGy of X-rays was manifested more strongly than in ovary tissue exposed to 600 cGy of X-rays, which was related to the phenomenon that granular cells of mature folliculus ovary underwent necrosis or apoptosis increasingly due to X-rays. In an electron microscope with high magnification, nuclei and protoplasm of granular cells in growing folliculus ovary abruptly underwent minute structural changes according to the increase of dose of X-rays. Cell residue, by-product of cell decease, neutrophil and macrophage around follicular antrum were observed. The minute structural changes in granular cells showed typical characteristics of apoptosis: the increase of electronic density due to nuclear condensation, fragmentation of nuclei and atrophy of protoplasm. Necrosis of cells was identified but it was not so remarkable. Macrophage with apoptotic bodies was scattered. Proportional to the radiation dose, we found that the generation of heterogeneous substance of normal ovary texture's follicular fluid, the emergence of dyeing characteristic in the basilar membrane of folicle, the generation of apoptosis, and the transformation of macrophages, etc. From this results, we can infer the possible radiation hazard on the overy of cervix cancer patient with radiation therapy.

  7. Progress in kinetic inductance thermometers for X-ray calorimeters

    International Nuclear Information System (INIS)

    Conventional X-ray microcalorimeters have so far used ion-implanted resistors for thermometers. Recently, however, several new methods for sensing small temperature changes have been suggested that are nondissipative. Such devices may have intrinsically better energy resolution by eliminating the Johnson noise present in resistive devices. The use of kinetic inductance thermometers for X-ray microcalorimeters is being investigated. This technique exploits the strong temperature dependence of magnetic penetration depth of thin superconducting films. The prototype system, designed for operation at 1.5 K, uses films of aluminum and tin. Once the expected temperature sensitivity and alpha particle detection have been demonstrated, aluminum will be replaced with titanium or another material with a suitable critical temperature and the device will be operated at 0.3 K. At this temperature, the energy resolution from thermal noise should be sufficiently good to allow X-ray detection. 12 refs

  8. Progress in kinetic inductance thermometers for X-ray calorimeters

    Science.gov (United States)

    Rawley, G. L.; Kelley, R. L.; Moseley, S. H.; Szymkowiak, A. E.

    1989-01-01

    Conventional X-ray microcalorimeters have so far used ionimplanted resistors for thermometers. Recently, however, several new methods for sensing small temperature changes have been suggested that are nondissipative. Such devices may have intrinsically better energy resolution by eliminating the Johnson noise present in resistive devices. The use of kinetic inductance thermometers for X-ray microcalorimeters is being investigated. This technique exploits the strong temperature dependence of magnetic penetration depth of thin superconducting films. The prototype system, designed for operation at 1.5 K, uses films of aluminum and tin. Once the expected temperature sensitivity and alpha particle detection have been demonstrated, aluminum will be replaced with titanium or another material with a suitable critical temperature and the device will be operated at 0.3 K. At this temperature, the energy resolution from thermal noise should be sufficiently good to allow X-ray detection.

  9. Aspergillosis - chest x-ray (image)

    Science.gov (United States)

    ... usually occurs in immunocompromised individuals. Here, a chest x-ray shows that the fungus has invaded the lung ... are usually seen as black areas on an x-ray. The cloudiness on the left side of this ...

  10. Stabilized x-ray generator power supply

    International Nuclear Information System (INIS)

    X-ray diffraction and X-ray fluorescence analysis are very much adopted in laboratories to determine the type and structure of the constituent compounds in solid materials, chemical composition of materials, stress developed on metals etc. These experiments need X-ray beam of fixed intensity and wave length. This can only be achieved by X-ray generator having highly stabilized tube voltage and tube current. This paper describes how X-ray tube high voltage and electron beam current are stabilized. This paper also highlights generation of X-rays, diffractometry and X-ray fluorescence analysis and their wide applications. Principle of operation for stabilizing the X-ray tube voltage and current, different protection circuits adopted, special features of the mains H.V. transformer and H.T. tank are described in this report. (author)

  11. Phase-sensitive X-ray imager

    Science.gov (United States)

    Baker, Kevin Louis

    2013-01-08

    X-ray phase sensitive wave-front sensor techniques are detailed that are capable of measuring the entire two-dimensional x-ray electric field, both the amplitude and phase, with a single measurement. These Hartmann sensing and 2-D Shear interferometry wave-front sensors do not require a temporally coherent source and are therefore compatible with x-ray tubes and also with laser-produced or x-pinch x-ray sources.

  12. Optical element for X-ray microscopy

    OpenAIRE

    Chadzitaskos, G.

    2008-01-01

    We present a proposal for a X-ray optical element suitable for X-ray microscopy and other X-ray-based display systems. Its principle is based on the Fresnel lenses condition and the Bragg condition for X-ray scattering on a slice of monocrystal. These conditions are fulfilled simultaneously due to a properly machined shape of the monocrystal with a stress at its ends.

  13. Characteristic x-ray emission from undermines plasmas irradiated by ultra-intense lasers

    Energy Technology Data Exchange (ETDEWEB)

    Niemann, Christoph

    2012-05-05

    Between FY09 and FY11 we have conducted more than a dozen three-week experimental campaigns at high-power laser facilities around the world to investigate laser-channeling through x-ray and optical imaging and the conversion from laser-energy to xrays. We have performed simultaneous two-wavelength x-ray imaging (K-alpha and He-alpha) to distinguish the hot-plasma region (hot-spot) from the laser-produced electrons (K-alpha). In addition, we have initiated a new collaboration with SNL and have performed first shots on the 100 TW beamlet chamber to commission a fast x-ray streak camera to be used to investigate the temporal evolution of our K-alpha sources. We also collaborated on campaigns at the Rutherford Appleton Laboratory (UK) and the LANL Trident laser to employ laser produced x-ray sources for Thomson scattering off dense matter.

  14. APOGEE chemical tagging constraint on the maximum star cluster mass in the $\\alpha$-enhanced Galactic disk

    CERN Document Server

    Ting, Yuan-Sen; Rix, Hans-Walter

    2015-01-01

    Stars born from the same molecular cloud should be nearly homogeneous in their element abundances. The concept of chemical tagging is to identify members of disrupted clusters by their clustering in element abundance space. Chemical tagging requires large samples of stars with precise abundances for many individual elements. With uncertainties of $\\sigma_{[X/{\\rm Fe}]}$ and $\\sigma_{\\rm [Fe/H]} \\simeq 0.05$ for 10 elements measured for $> 10^4$ stars, the APOGEE DR12 spectra may be the first well-suited data set to put this idea into practice. We find that even APOGEE data offer only $\\sim 500$ independent volume elements in the 10-dimensional abundance space, when we focus on the $\\alpha$-enhanced Galactic disk. We develop and apply a new algorithm to search for chemically homogeneous sets of stars against a dominant background. By injecting star clusters into the APOGEE data set we show that chemically homogeneous clusters with masses $\\gtrsim 3 \\times 10^7 \\, {\\rm M}_\\odot$ would be easily detectable and y...

  15. Center for X-ray Optics, 1988

    Energy Technology Data Exchange (ETDEWEB)

    1989-04-01

    This report briefly reviews the following topics: soft-x-ray imaging; reflective optics for hard x-rays; coherent XUV sources; spectroscopy with x-rays; detectors for coronary artery imaging; synchrotron-radiation optics; and support for the advanced light source.

  16. X-Ray Exam: Neck (For Parents)

    Science.gov (United States)

    ... Tropical Delight: Melon Smoothie Pregnant? Your Baby's Growth X-Ray Exam: Neck KidsHealth > For Parents > X-Ray Exam: Neck Print A A A Text Size ... español Radiografía: cuello What It Is A neck X-ray is a safe and painless test that uses ...

  17. Cryotomography x-ray microscopy state

    Science.gov (United States)

    Le Gros, Mark; Larabell, Carolyn A.

    2010-10-26

    An x-ray microscope stage enables alignment of a sample about a rotation axis to enable three dimensional tomographic imaging of the sample using an x-ray microscope. A heat exchanger assembly provides cooled gas to a sample during x-ray microscopic imaging.

  18. Electron beam parallel X-ray generator

    Science.gov (United States)

    Payne, P.

    1967-01-01

    Broad X ray source produces a highly collimated beam of low energy X rays - a beam with 2 to 5 arc minutes of divergence at energies between 1 and 6 keV in less than 5 feet. The X ray beam is generated by electron bombardment of a target from a large area electron gun.

  19. Center for X-ray Optics, 1988

    International Nuclear Information System (INIS)

    This report briefly reviews the following topics: soft-x-ray imaging; reflective optics for hard x-rays; coherent XUV sources; spectroscopy with x-rays; detectors for coronary artery imaging; synchrotron-radiation optics; and support for the advanced light source

  20. X-ray tracing using Geant4

    International Nuclear Information System (INIS)

    We describe an extension to the Geant4 software package that allows it to be used as a general purpose X-ray tracing package. We demonstrate the use of our extension by building a model of the X-ray optics of the X-ray observatory XMM-Newton, calculating its effective area, and comparing the results with the published calibration curves.

  1. Dependence of X-Ray Burst Models on Nuclear Reaction Rates

    OpenAIRE

    Cyburt, R. H.; Amthor, A. M.; Heger, A.; Johnson, E.; Keek, L.; Meisel, Z.; Schatz, H.; Smith, K

    2016-01-01

    X-ray bursts are thermonuclear flashes on the surface of accreting neutron stars and reliable burst models are needed to interpret observations in terms of properties of the neutron star and the binary system. We investigate the dependence of X-ray burst models on uncertainties in (p,$\\gamma$), ($\\alpha$,$\\gamma$), and ($\\alpha$,p) nuclear reaction rates using fully self-consistent burst models that account for the feedbacks between changes in nuclear energy generation and changes in astrophy...

  2. X-Ray Resonant Photoexcitation: Linewidths and Energies of Kα Transitions in Highly Charged Fe Ions

    OpenAIRE

    Rudolph, J; Bernitt, S; Epp, S.; Steinbrügge, R.; Beilmann, C.; Brown, G.; Eberle, S.; A. Graf; Harman, Z.; Hell, N.; Leutenegger, M.; Müller, A.; Schlage, K.; Wille, H; Yavas, H.

    2013-01-01

    Photoabsorption by and fluorescence of the K{\\alpha} transitions in highly charged iron ions are essential mechanisms for X-ray radiation transfer in astrophysical environments. We study photoabsorption due to the main K{\\alpha} transitions in highly charged iron ions from heliumlike to fluorinelike (Fe 24+...17+) using monochromatic X-rays around 6.6 keV at the PETRA III synchrotron photon source. Natural linewidths were determined with hitherto unattained accuracy. The observed transitions ...

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

    Science.gov (United States)

    Macfarlane, J. J.

    1994-01-01

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

  4. Zernike x-ray ptychography.

    Science.gov (United States)

    Vartiainen, Ismo; Mohacsi, Istvan; Stachnik, Karolina; Guizar-Sicairos, Manuel; David, Christian; Meents, Alke

    2016-02-15

    We present an imaging technique combining Zernike phase-contrast imaging and ptychography. The contrast formation is explained by following the theory of Zernike phase-contrast imaging. The method is demonstrated with x-rays at a photon energy of 6.2 keV, showing how ptychographic reconstruction of a phase sample leads to a Zernike phase-contrast image appearing in the amplitude reconstruction. In addition, the results presented in this Letter indicate an improvement of the resolution of the reconstructed object in the case of Zernike ptychography compared with the conventional one. PMID:26872172

  5. Protonium X-ray spectroscopy

    CERN Document Server

    Gotta, D

    1999-01-01

    The Lyman and Balmer transitions from antiprotonic hydrogen and deuterium were studied extensively at the low-energy-antiproton ring LEAR at CERN in order to determine the strong interaction effects. A first series of experiments $9 was performed with semiconductor and gaseous X-ray detectors. In the last years of LEAR operation using a Bragg crystal spectrometer, strong interaction parameters in the 2p states of antiprotonic hydrogen and deuterium were measured $9 directly. The results of the measurements support the meson-exchange models describing the medium and long range part of the nucleon-antinucleon interaction. (39 refs).

  6. X-ray tomographic apparatus

    International Nuclear Information System (INIS)

    An x-ray tomographic system consists of a radiation source such as gamma or x radiation which produces a fan-shaped beam. The fan is wide enough to encompass the patient circle. The system further includes means for rotating the radiation source about the patient for less than a full rotation, and detectors for detecting the radiation at positions that surround the patient by 1800 plus the angle of the fan beam plus the angle between adjacent fan detectors. Attenuation data from the detectors is sorted into detector fans of attenuation data, then processed. The convolved data is back-projected into an image memory and displayed on a video monitor

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

    OpenAIRE

    Schmidtke, P. C.; Cowley, A. P.

    2005-01-01

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

  8. Comets: mechanisms of x-ray activity

    Science.gov (United States)

    Ibadov, Subhon

    2016-07-01

    Basic mechanisms of X-ray activity of comets are considered, including D-D mechanism corresponding to generation of X-rays due to production of hot short-living plasma clumps at high-velocity collisions between cometary and interplanetary dust particles as well as M-M one corresponding to production of X-rays due to recombination of multicharge ions of solar wind plasma via charge exchange process at their collisions with molecules/atoms of the cometary atmospheres. Peculiarities of the variation of the comet X-ray spectrum and X-ray luminosity with variation of its heliocentric distance are revealed.

  9. Swift Observations of X-ray supernovae

    OpenAIRE

    Li, K. L.; Pun, Chun. S. J.

    2011-01-01

    We present a result of X-ray supernovae (SNe) survey using the Swift satellite public archive. An automatic searching program was designed to search X-ray SNe among all of the Swift archival observations between November 2004 and February 2011. Using the C++ program, 24 X-ray detectable supernovae have been found in the archive and 3 of them were newly-discovered in X-rays which are SN 1986L, SN 2003lx, and SN 2007od. In addition, SN 2003lx is a Type Ia supernova which may be the second X-ray...

  10. X-ray Spectroscopy of Cooling Cluster

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-01-17

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

  11. Symbiotic stars in X-rays

    OpenAIRE

    Luna, G. J. M.; Sokoloski, J. L.; Mukai, K; Nelson, T.

    2012-01-01

    Until recently, symbiotic binary systems in which a white dwarf accretes from a red giant were thought to be mainly a soft X-ray population. Here we describe the detection with the X-ray Telescope (XRT) on the Swift satellite of nine white dwarf symbiotics that were not previously known to be X-ray sources and one that had previously been detected as a supersoft X-ray source. The nine new X-ray detections were the result of a survey of 41 symbiotic stars, and they increase the number of symbi...

  12. Amplification and variability of the AGN X-ray emission due to microlensing

    OpenAIRE

    Popovic, L. C.; Jovanovic, P; Petrovic, T.; Shalyapin, V. N.

    2006-01-01

    We consider the contribution of microlensing to the AGN Fe K$\\alpha$ line and X-ray continuum amplification and variation. To investigate the variability of the line and X-ray continuum, we studied the effects of microlensing on quasar X-ray spectra produced by crossing of a microlensing pattern across a standard relativistic accretion disk. To describe the disk emission we used a ray tracing method considering both metrics, Schwarzschild and Kerr. We found that the Fe K$\\alpha$ and continuum...

  13. X-ray state analysis by means of electron capture decay

    Energy Technology Data Exchange (ETDEWEB)

    Tamaki, Yoichi [Miyagi Univ. of Education, Sendai (Japan)

    1998-01-01

    K{alpha} X-ray induced by EC decay of {sup 55}Fe and {sup 71}Ge-labeled compounds were measured by wavelength dispersive X-ray spectrometer equipped position sensitive proportional detector. In both nuclides, peak energies of K{alpha}{sub 2} X-rays are lower (-0.4 - -0.6 eV) than those of Mn and Ga compounds by photoionization. It is thought that the causes of these differences are intensity of high energy satellite peaks by shake up process. (author)

  14. Computer solutions for studying correlations between solar magnetic fields and Skylab X-ray observations

    Science.gov (United States)

    Teuber, D.; Tandberg-Hanssen, E.; Hagyard, M. J.

    1977-01-01

    A method is described which correlates the NASA-Marshall Space Flight Center (MSFC) Image Data Processing System (IDAPS) and MSFC magnetograph data to X-ray and H-alpha observations from the Skylab mission. Solutions of Laplace's equation in three dimensions, based on the magnetograph data, are convolved with observed X-ray and H-alpha regions. Matched filtering (template matching) provides a best fit of the observed X-ray regions to the computed total magnetic vector magnitude between 10,000 and 15,000 km above the photosphere.

  15. Miniature x-ray point source for alignment and calibration of x-ray optics

    International Nuclear Information System (INIS)

    A miniature x-ray point source of high brightness similar to that of Rovinsky, et al. is described. One version of the x-ray source is used to align the x-ray optics on the Argus and Shiva laser systems. A second version is used to determine the spatial and spectral transmission functions of the x-ray optics. The spatial and spectral characteristics of the x-ray emission from the x-ray point source are described. The physical constraints including size, intensity and thermal limitations, and useful lifetime are discussed. The alignment and calibration techniques for various x-ray optics and detector combinations are described

  16. Management of dental x-ray exposure

    International Nuclear Information System (INIS)

    The effects of dental x-ray exposure and how they might be minimized were reviewed. The frequency of dental x-ray exposures in Japan was presented for each year, sex, age group and site of x-ray photography separately. The doses of exposure at various parts of the body per x-ray examination were also presented, and the probabilities of genetic damage, and of development of leukemia or cancer were calculated. The allowable dose of exposure for radiation workers was discussed. It is important to take account of radiation quality, area of irradiation field, and posture of patients to minimize the radiation effect. The actual statistics on the x-ray exposure at the dentists, distribution of the dispersed radiation in the x-ray room, methods of protection against exposure, and plans and designs of the x-ray room were discussed. (Kaihara, S.)

  17. X ray imaging microscope for cancer research

    Science.gov (United States)

    Hoover, Richard B.; Shealy, David L.; Brinkley, B. R.; Baker, Phillip C.; Barbee, Troy W., Jr.; Walker, Arthur B. C., Jr.

    1991-01-01

    The NASA technology employed during the Stanford MSFC LLNL Rocket X Ray Spectroheliograph flight established that doubly reflecting, normal incidence multilayer optics can be designed, fabricated, and used for high resolution x ray imaging of the Sun. Technology developed as part of the MSFC X Ray Microscope program, showed that high quality, high resolution multilayer x ray imaging microscopes are feasible. Using technology developed at Stanford University and at the DOE Lawrence Livermore National Laboratory (LLNL), Troy W. Barbee, Jr. has fabricated multilayer coatings with near theoretical reflectivities and perfect bandpass matching for a new rocket borne solar observatory, the Multi-Spectral Solar Telescope Array (MSSTA). Advanced Flow Polishing has provided multilayer mirror substrates with sub-angstrom (rms) smoothnesss for the astronomical x ray telescopes and x ray microscopes. The combination of these important technological advancements has paved the way for the development of a Water Window Imaging X Ray Microscope for cancer research.

  18. Combining Single-Molecule Optical Trapping and Small-Angle X-Ray Scattering Measurements to Compute the Persistence Length of a Protein ER/K alpha-Helix

    DEFF Research Database (Denmark)

    Sivaramakrishnan, S.; Sung, J.; Ali, M.;

    2009-01-01

    A relatively unknown protein structure motif forms stable isolated single alpha-helices, termed ER/K alpha-helices, in a wide variety of proteins and has been shown to be essential for the function of some molecular motors. The flexibility of the ER/K alpha-helix determines whether it behaves as a...

  19. Parametric X-Ray Radiation

    Science.gov (United States)

    Shchagin, Alexander

    1997-10-01

    The main PXR properties [1,2] are considered in the paper: energy, width, smooth tuning of monochromatic PXR spectral line; fine structure and absolute differential yields of PXR in the vicinity of and at angular distances from Brag directions; angular spread of the PXR beam; the influence of incident electron energy and of the density effect on the PXR properties; linear polarization of PXR; background in PXR spectra. Experimental setups for linacs and the results of measurements are discussed. Experimental data are compared to theoretical calculations at PXR energies between 5 and 400 keV for incident electron energies ranging from 15 to 1200 MeV. Possible applications of PXR as a new source of a bright, tunable X-ray beam in science and industry are discussed. [1] A.V. Shchagin and N.A. Khizhnyak, NIM B119, 115-122 (1996). [2] A.V. Shchagin and X.K. Maruyama, "Parametric X-rays", a chapter in the book "Accelerator-based Atomic Physics Techniques and Applications", edited by S.M. Shafroth and J.C. Austin, AIP Press, 1997, pp 279-307.

  20. Full-field transmission x-ray imaging with confocal polycapillary x-ray optics

    OpenAIRE

    Sun, Tianxi; MacDonald, C. A.

    2013-01-01

    A transmission x-ray imaging setup based on a confocal combination of a polycapillary focusing x-ray optic followed by a polycapillary collimating x-ray optic was designed and demonstrated to have good resolution, better than the unmagnified pixel size and unlimited by the x-ray tube spot size. This imaging setup has potential application in x-ray imaging for small samples, for example, for histology specimens.

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

    CERN Document Server

    Mori, Kaya; Krivonos, Roman; Hong, Jaesub; Ponti, Gabriele; Bauer, Franz; Perez, Kerstin; Nynka, Melania; Zhang, Shuo; Tomsick, John A; Alexander, David M; Baganoff, Frederick K; Barret, Didier; Barriere, Nicolas; Boggs, Steven E; Canipe, Alicia M; Christensen, Finn E; Craig, William W; Forster, Karl; Giommi, Paolo; Grefenstette, Brian W; Grindlay, Jonathan E; Harrison, Fiona A; Hornstrup, Allan; Kitaguchi, Takao; Koglin, Jason E; Luu, Vy; Madsen, Kristen K; Mao, Peter H; Miyasaka, Hiromasa; Perri, Matteo; Pivovaroff, Michael J; Puccetti, Simonetta; Rana, Vikram; Stern, Daniel; Westergaard, Niels J; Zhang, William W; Zoglauer, Andreas

    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). NuSTAR detects four non-thermal X-ray filaments, extending the detection of their power-law spectra with $\\Gamma\\sim1.3$-$2.3$ 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 K$\\alpha$ fluorescence line emission associated with two Sgr A molecular clouds: MC1 and the Bridge. Broad-band X-ray spectral analysis with a Monte-Carlo based X-ray reflection model self-consistently determined their intrinsic column density ($\\sim10^{23}$ cm$^{-2}$), primary X-ray spectra (power-laws wi...

  2. The X-ray emission of 3C273

    Energy Technology Data Exchange (ETDEWEB)

    Turner, M.J.L.; Williams, O.R. (Leicester Univ. (UK). Dept. of Astronomy); Courvoisier, T.J.-L. (Geneva Observatory (Switzerland)) (and others)

    1990-05-15

    The X-ray emission of 3C273 in the 0.2-35 keV band has been studied, with EXOSAT and Ginga, over the period 1983 December to 1988 December. The overall flux is variable on a time-scale of weeks by a factor of 2. The spectral index in the 2-10 keV band ({alpha} {approx} 0.5) is significantly different from the 'canonical' AGN index of {alpha} = 0.7. There are small but significant variations with time in the spectral index which are not statistically correlated with the overall X-ray flux level. Iron emission with an equivalent width of {approx} 50 eV is detected in one of the Ginga observations. (author).

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

    Science.gov (United States)

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

    2000-01-01

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

  4. X-ray microtomography: applications and developments

    International Nuclear Information System (INIS)

    Full text: X-ray microtomography has followed a classical development path being originally available only to those with the expertise to piece together the often cumbersome components to required to make a practical x-ray microtomography system. Subsequent technological and scientific advances have meant that x-ray microtomography instruments are now off-the-shelf items with a cost well within the equipment budgets of research institutions and industry. The technological advances that have contributed to the development of x-ray microtomography include commercially available x-ray micro-sources, high-resolution CCD cameras and highspeed, low-cost computers. The scientific developments have been predominantly in image reconstruction. Some of these scientific developments are, with the advantage of hindsight, very simple while others, such as resolution enhancement using the Fresnel fringes in x-ray projection images, are not so intuitive. As a consequence of the availability of 'black-box' instruments, x-ray microtomography is spreading to a wide range of applications. The materials most suited to examination by x-ray microtomography are those with a medium level of x-ray absorption such as bone, teeth, rocks, porous metals, composite materials and plant materials. For these materials, 3D information can be obtained at resolutions comparable to the resolution of a high-quality optical microscope. A few of these applications will be demonstrated in the presentation. Technological advances that aid x-ray microtomography will continue with x-ray sources becoming smaller, computers becoming faster and CCD cameras having increased numbers of pixels. It will be interesting to see if nano x-ray microtomography is achieved. Developments in x-ray microtomography are required in areas such as contrast enhancement particularly for problematic materials such as soft tissue and low-density polymers. For low-density polymers x-ray absorption is very low while for soft tissue

  5. Evolution of chromospheres and coronae in solar mass stars: A far-ultraviolet and soft x-ray comparison of Arcturus (K2III) and Alpha Centauri A (G2 V)

    International Nuclear Information System (INIS)

    We compare IUE far-ultraviolet and Einstein soft X-ray observations of the red giant Arcturus (α Bootis, K2III) and the nearby yellow dwarf α Centauri A (G2 V), which are archetypes of solar mass stars in very different stages of evolution. We find no evidence for coronal (Troughly-equal106 K) soft X-ray emission from the red giant at surface flux levels of only 0.0006 (3sigma) that detected previously for α Cen A, and no evidence for C IV lambdalambda1548, 1551 (Troughly-equal105 K) or C II lambdalambda1335, 1336 (Troughly-equal2 x 104 K) resonance line emission at surface flux levels of only 0.02 (3sigma) those of the yellow dwarf. Instead of a solar-like hot corona and warm (Troughly-equal105 K) transition region, the resonance line upper limits and previous detections of the C II intersystem UV multiplet 0.01 near 2325 A provide evidence that the outer atmosphere of Arcturus is geometrically extended (Δhapprox.R/sub */), tenuous (n/sub e/roughly-equal3 x 108 cm-3), and cool (T4 K)

  6. TW Hya: Spectral Variability, X-Rays, and Accretion Diagnostics

    CERN Document Server

    Dupree, A K; Cranmer, S R; Luna, G J M; Schneider, E E; Bessell, M S; Bonanos, A; Crause, L A; Lawson, W A; Mallik, S V; Schuler, S C

    2012-01-01

    The nearest accreting T Tauri star, TW Hya was observed with spectroscopic and photometric measurements simultaneous with a long se gmented exposure using the CHANDRA satellite. Contemporaneous optical photometry from WASP-S indicates a 4.74 day period was present during this time. Absence of a similar periodicity in the H-alpha flux and the total X-ray flux points to a different source of photometric variations. The H-alpha emission line appears intrinsically broad and symmetric, and both the profile and its variability suggest an origin in the post-shock cooling region. An accretion event, signaled by soft X-rays, is traced spectroscopically for the first time through the optical emission line profiles. After the accretion event, downflowing turbulent material observed in the H-alpha and H-beta lines is followed by He I (5876A) broadening. Optical veiling increases with a delay of about 2 hours after the X-ray accretion event. The response of the stellar coronal emission to an increase in the veiling follow...

  7. Anomalous x-ray scattering

    International Nuclear Information System (INIS)

    The availability of tunable synchrotron radiation has made it possible systematically to perform x-ray diffraction studies in regions of anomalous scattering near absorption edges, e.g. in order to derive phase information for crystal structure determination. An overview is given of recent experimental and theoretical work and discuss the properties of the anomalous atomic scattering factor, with emphasis on threshold resonances and damping effects. The results are applied to a discussion of the very strong anomalous dispersion recently observed near the L3 edge in a cesium complex. Also given is an overview of elements and levels where similar behavior can be expected. Finally, the influence of solid state and chemical effects on the absorption edge structure is discussed. 64 references

  8. Submicron X-ray diffraction

    International Nuclear Information System (INIS)

    At the Advanced Light Source in Berkeley the authors have instrumented a beam line that is devoted exclusively to x-ray micro diffraction problems. By micro diffraction they mean those classes of problems in Physics and Materials Science that require x-ray beam sizes in the sub-micron range. The beam line has a unity magnification toroidal mirror that produces a 50 by 200 micron focus just inside an x-ray hutch at the position of an x-y slit. The beam path in the hutch consists of source defining slits, a four bounce Ge or Si monochromator, followed by elliptically bent Kirkpatrick-Baez mirror pair which focuses the beam from the slits to sub micron dimensions (0.8 x 0.8 microns). An important feature of this arrangement is the ability to switch between white and monochromatic beams that are essential for characterizing crystals or crystal grains in the sub-micron range. Since sample rotation is fixed they have facilities for precision translation of the specimen to allow them to scan different crystal regions or grains. The sample stage rests on a state of the art six-circle diffractometer equipped with encoders in the main rotation stages calibrated to a second of arc. The detector is a 4K x 4K CCD (Bruker) with a 9 x 9 cm view area mounted on a detector arm that can be positioned around the sample. The detector itself can also be positioned to better than 1 micron along the detector arm. Using this facility they have been able to measure the orientation structure of single grains of passivated or buried Al interconnect test structures. Such structures or their equivalents are important in connecting individual components on integrated circuits. Their sub-micron dimensions result in very high current densities that can result in interconnect failures. The variation in sub-grain structure in a single grain is rich in detail. They have obtained detailed maps of misorientations in single grains using white beam Laue diffraction patterns From these they have been

  9. X-ray intensifying screens

    International Nuclear Information System (INIS)

    An x-ray intensifying screen comprises a support which has a luminescent composition comprising an isotropic phosphor and a polymer having an index of refraction within 0.02 of that of the phosphor over at least 80 percent of its emission spectrum. The support has an index of refraction up to or equal to 0.05 units higher than that of the phosphor and has a reflection optical density of at least 1.7 to light emitted by the phosphor. A preferred luminescent composition comprises Kl:Tl, Rbl:Tl at BaSrFCl:Eu mixed with two monomers such as 1-naphthylmethylmethacrylate, S(1-naphthylmethyl) thioacrylate, 1-bromo-2-naphthylacrylate, and benzyl methacrylate, coated on black anodised Al and polymerised in situ. The ratio of monomers is adjusted to give the desired refractive index. Other phosphors, polymers and supports are specified together with the preparation of the monomers and polymers. (author)

  10. X-ray flat panel detectors and X-ray tubes contributing to development of X-ray diagnostic systems

    International Nuclear Information System (INIS)

    X-ray flat panel detectors (FPDs) and X-ray tubes are key devices allowing X-ray diagnostic systems to support more sophisticated medical care. FPDs provide valuable information for the diagnosis of various diseases through the conversion of X-ray images of the human body into electronic signals, while X-ray tubes are used in a wide range of applications such as computed tomography (CT), angiography, fluoroscopy, mammography, and dental systems. Toshiba Electron Tubes and Devices Co., Ltd. has developed and commercialized FPDs providing high-quality diagnostic X-ray images with low dose exposure through the development of cutting-edge technologies including a fine crystal formation technology for cesium iodide (CsI) scintillators, thin-film transistor (TFT) arrays with photodiodes, and so on. In the field of X-ray tubes that can generate a high output of X-rays, we have developed a liquid metal hydrodynamic bearing (LM bearing) technology for various diagnostic systems including medical CT systems with a long lifetime and high rotation speed, and cardiovascular imaging systems with quiet operation. Furthermore, LM bearing technology reduces the burden on the environment by replacing insulating oil with water coolant for the cooling system and making the X-ray tubes more compact. (author)

  11. Development of confocal micro X-ray fluorescence instrument using two X-ray beams

    International Nuclear Information System (INIS)

    A new confocal micro X-ray fluorescence instrument was developed. This instrument has two independent micro X-ray tubes with Mo targets. A full polycapillary X-ray lens was attached to each X-ray tube. Another half polycapillary lens was attached to a silicon drift X-ray detector (SDD). The focal spots of the three lenses were adjusted to a common position. The effects of the excitation of two X-ray beams were investigated. The instrument enabled highly sensitive three-dimensional X-ray fluorescence analysis. We confirmed that the X-ray fluorescence intensity from the sample increased by applying the two independent X-ray tubes in confocal configuration. Elemental depth profiling of black wheat was demonstrated with the result that each element in the surface coat of a wheat grain showed unique distribution

  12. Acoustooptics of x-rays

    Energy Technology Data Exchange (ETDEWEB)

    Balakhanov, M.V.; Pustovoyt, V.I.; Radzhabov, R.U.; Khabibullayev, P.K.

    Scattering of x-rays by acoustic phonons in crystals during excitation of a noise phonon flux thermodynamically at equilibrium is analyzed from the standpoint of the dynamic diffraction theory, emphasis being put on the differences with the conventional acoustooptic effect attributable to lower frequencies and smaller amplitudes. The structural peak and the diffusional peak are calculated from known relations for the intensity of scattering in each mode, assuming that the Laue condition is satisfied. Interaction of x-rays and an acoustic wave is considered, the conditions for a diffraction peak being determined by the relations between location of that peak and angular dimensions of the structural peak. Experiments were performed in crystals of photosensitive piezoelectric semiconductors with phonon generation. Rectangular or variable-shape voltage pulses with amplitudes up to 800 V were applied to 6-60 ..mu..m thick CdS crystals at repetition rates up to 800 Hz. The electron concentration was (1.3-4.5) x 10/sup 14/ cm/sup -3/ and the electron mobility, according to saturation of the current-voltage characteristics, was differentially in time. The results reveal sharp anisotropy of scattering, evident in the dependence of scattering intensity on the angle of crystal rotation and the resulting lobar scattering pattern. Structural scattering varies exponentially and diffusional scattering varies linearly with increasing amplitude of the applied voltage. According to the dependence of the spectral density of phonon generation on the concentration of charge carriers, the phase of the scattering effect changes upon transition from the structural range to the diffusional range. 8 references, 3 figures.

  13. Soft x-ray interferometry

    International Nuclear Information System (INIS)

    The purpose of the soft x-ray interferometry workshop held at Lawrence Berkeley Laboratory was to discuss with the scientific community the proposed technical design of the soft x-ray Fourier-transform spectrometer being developed at the ALS. Different design strategies for the instrument's components were discussed, as well as detection methods, signal processing issues, and how to meet the manufacturing tolerances that are necessary for the instrument to achieve the desired levels of performance. Workshop participants were encouraged to report on their experiences in the field of Fourier transform spectroscopy. The ALS is developing a Fourier transform spectrometer that is intended to operate up to 100 eV. The motivation is solely improved resolution and not the throughput (Jaquinot) or multiplex (Fellgett) advantage, neither of which apply for the sources and detectors used in this spectral range. The proposed implementation of this is via a Mach-Zehnder geometry that has been (1) distorted from a square to a rhombus to get grazing incidence of a suitable angle for 100 eV and (2) provided with a mirror-motion system to make the path difference between the interfering beams tunable. The experiment consists of measuring the emergent light intensity (I(x)) as a function of the path difference (x). The resolving power of the system is limited by the amount of path difference obtainable that is 1 cm (one million half-waves at 200 angstrom wavelength) in the design thus allowing a resolving power of one million. The free spectral range of the system is limited by the closeness with which the function I(x) is sampled. It is proposed to illuminate a helium absorption cell with roughly 1%-band-width light from a monochromator thus allowing one hundred aliases without spectral overlap even for sampling of I(x) at one hundredth of the Nyquist frequency

  14. Forensic application of total reflection X-ray fluorescence spectrometry for elemental characterization of ink samples

    Energy Technology Data Exchange (ETDEWEB)

    Dhara, Sangita [Fuel Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Misra, N.L., E-mail: nlmisra@barc.gov.i [Fuel Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Maind, S.D. [NAA Unit of Central Forensic Science Laboratory Hyderabad at Analytical Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Kumar, Sanjukta A. [Analytical Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Chattopadhyay, N. [NAA Unit of Central Forensic Science Laboratory Hyderabad at Analytical Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Aggarwal, S.K. [Fuel Chemistry Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)

    2010-02-15

    The possibility of applying Total Reflection X-ray Fluorescence for qualitative and quantitative differentiation of documents printed with rare earth tagged and untagged inks has been explored in this paper. For qualitative differentiation, a very small amount of ink was loosened from the printed documents by smoothly rubbing with a new clean blade without destroying the manuscript. 50 muL of Milli-Q water was put on this loose powder, on the manuscript, and was agitated by sucking and releasing the suspension two to three times with the help of a micropipette. The resultant dispersion was deposited on quartz sample support for Total Reflection X-ray Fluorescence measurements. The Total Reflection X-ray Fluorescence spectrum of tagged and untagged inks could be clearly differentiated. In order to see the applicability of Total Reflection X-ray Fluorescence for quantitative determinations of rare earths and also to countercheck such determinations in ink samples, the amounts of rare earth in painted papers with single rare earth tagged inks were determined by digesting the painted paper in HNO{sub 3}/HClO{sub 4}, mixing this solution with the internal standard and recording their Total Reflection X-ray Fluorescence spectra after calibration of the instrument. The results thus obtained were compared with those obtained by Inductively Coupled Plasma Mass Spectrometry and were found in good agreement. The average precision of the Total Reflection X-ray Fluorescence determinations was 5.5% (1sigma) and the average deviation of Total Reflection X-ray Fluorescence determined values with that of Inductively Coupled Plasma Mass Spectrometry was 7.3%. These studies have shown that Total Reflection X-ray Fluorescence offers a promising and potential application in forensic work of this nature.

  15. Forensic application of total reflection X-ray fluorescence spectrometry for elemental characterization of ink samples

    International Nuclear Information System (INIS)

    The possibility of applying Total Reflection X-ray Fluorescence for qualitative and quantitative differentiation of documents printed with rare earth tagged and untagged inks has been explored in this paper. For qualitative differentiation, a very small amount of ink was loosened from the printed documents by smoothly rubbing with a new clean blade without destroying the manuscript. 50 μL of Milli-Q water was put on this loose powder, on the manuscript, and was agitated by sucking and releasing the suspension two to three times with the help of a micropipette. The resultant dispersion was deposited on quartz sample support for Total Reflection X-ray Fluorescence measurements. The Total Reflection X-ray Fluorescence spectrum of tagged and untagged inks could be clearly differentiated. In order to see the applicability of Total Reflection X-ray Fluorescence for quantitative determinations of rare earths and also to countercheck such determinations in ink samples, the amounts of rare earth in painted papers with single rare earth tagged inks were determined by digesting the painted paper in HNO3/HClO4, mixing this solution with the internal standard and recording their Total Reflection X-ray Fluorescence spectra after calibration of the instrument. The results thus obtained were compared with those obtained by Inductively Coupled Plasma Mass Spectrometry and were found in good agreement. The average precision of the Total Reflection X-ray Fluorescence determinations was 5.5% (1σ) and the average deviation of Total Reflection X-ray Fluorescence determined values with that of Inductively Coupled Plasma Mass Spectrometry was 7.3%. These studies have shown that Total Reflection X-ray Fluorescence offers a promising and potential application in forensic work of this nature.

  16. Soft x-ray polarimeter laboratory tests

    Science.gov (United States)

    Murphy, Kendrah D.; Marshall, Herman L.; Schulz, Norbert S.; Jenks, Kevin; Sommer, Sophie J. B.; Marshall, Eric A.

    2010-07-01

    Multilayer-coated optics can strongly polarize X-rays and are central to a new design of a broad-band, soft X-ray polarimeter. We have begun laboratory work to verify the performance of components that could be used in future soft X-ray polarimetric instrumentation. We have reconfigured a 17 meter beamline facility, originally developed for testing transmission gratings for Chandra, to include a polarized X-ray source, an X-ray-dispersing transmission grating, and a multilayer-coated optic that illuminates a CCD detector. The X-rays produced from a Manson Model 5, multi-anode source are polarized by a multilayer-coated flat mirror. The current configuration allows for a 180 degree rotation of the source in order to rotate the direction of polarization. We will present progress in source characterization and system modulation measurements as well as null and robustness tests.

  17. X-rays for medical use

    Science.gov (United States)

    Hessenbruch, A.

    1995-11-01

    1995 is the centenary of the discovery of X-rays by the German physicist Wilhelm C Rontgen. In the past hundred years, the new rays have developed from being unknown to finding application in many walks of life, not least in medicine. This is so much so that in common speech the word `x-ray` refers not to a form of radiation but to an X-ray photograph taken for the purposes of diagnosis (as in: `I had an X-ray done to see if my leg was broken`). X-rays are now used routinely, and they are used both for diagnosis and for therapy. This paper will give an outline of the use of X-rays in medicine throughout our present century.

  18. Handbook of X-Ray Data

    CERN Document Server

    Zschornack, Günter

    2007-01-01

    This sourcebook is intended as an X-ray data reference for scientists and engineers working in the field of energy or wavelength dispersive X-ray spectrometry and related fields of basic and applied research, technology, or process and quality controlling. In a concise and informative manner, the most important data connected with the emission of characteristic X-ray lines are tabulated for all elements up to Z = 95 (Americium). This includes X-ray energies, emission rates and widths as well as level characteristics such as binding energies, fluorescence yields, level widths and absorption edges. The tabulated data are characterized and, in most cases, evaluated. Furthermore, all important processes and phenomena connected with the production, emission and detection of characteristic X-rays are discussed. This reference book addresses all researchers and practitioners working with X-ray radiation and fills a gap in the available literature.

  19. Clinical X-ray diagnostics. v. 1

    International Nuclear Information System (INIS)

    After introductory remarks on historical aspects of the development of X-ray diagnostics, the physical and technological fundamentals of the generation and recording of radiographs are elaborated. In a comprehensive chapter such topics as X-rays, X-ray tubes, X-ray generators, contrast media, interrelations between X-rays and patients as well as classical and recent methods of recording with regard to geometrical conditions, and of picture quality are outlined. Brief notes on analysis, documentation and filing of radiographs are added. Physico-technological fundamentals of radiation protection, remarks concerning radiation protection in the GDR, and special problems of radiation protection as to X-ray diagnostics are discussed

  20. Radiation safety in X-ray facilities

    International Nuclear Information System (INIS)

    The guide specifies the radiation safety requirements for structural shielding and other safety arrangements used in X-ray facilities in medical and veterinary X-ray activities and in industry, research and education. The guide is also applicable to premises in which X-ray equipment intended for radiation therapy and operating at a voltage of less than 25 kV is used. The guide applies to new X-ray facilities in which X-ray equipment that has been used elsewhere is transferred. The radiation safety requirements for radiation therapy X-ray devices operating at a voltage exceeding 25 kV, and for the premices in which such devices are used, are set out in Guide ST 2.2

  1. Radiation safety in X-ray facilities

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-09-01

    The guide specifies the radiation safety requirements for structural shielding and other safety arrangements used in X-ray facilities in medical and veterinary X-ray activities and in industry, research and education. The guide is also applicable to premises in which X-ray equipment intended for radiation therapy and operating at a voltage of less than 25 kV is used. The guide applies to new X-ray facilities in which X-ray equipment that has been used elsewhere is transferred. The radiation safety requirements for radiation therapy X-ray devices operating at a voltage exceeding 25 kV, and for the premices in which such devices are used, are set out in Guide ST 2.2.

  2. X-ray microlaminography with polycapillary optics

    International Nuclear Information System (INIS)

    We demonstrate layer-by-layer x-ray microimaging using polycapillary optics. The depth resolution is achieved without sample or source rotation and in a way similar to classical tomography or laminography. The method takes advantage from large angular apertures of polycapillary optics and from their specific microstructure, which is treated as a coded aperture. The imaging geometry is compatible with polychromatic x-ray sources and with scanning and confocal x-ray fluorescence setups.

  3. X-ray microlaminography with polycapillary optics

    Science.gov (United States)

    Dąbrowski, K. M.; Dul, D. T.; Wróbel, A.; Korecki, P.

    2013-06-01

    We demonstrate layer-by-layer x-ray microimaging using polycapillary optics. The depth resolution is achieved without sample or source rotation and in a way similar to classical tomography or laminography. The method takes advantage from large angular apertures of polycapillary optics and from their specific microstructure, which is treated as a coded aperture. The imaging geometry is compatible with polychromatic x-ray sources and with scanning and confocal x-ray fluorescence setups.

  4. X-ray spot film device

    International Nuclear Information System (INIS)

    Improvements are described in an X-ray spot film device which is used in conjunction with an X-ray table to make a selected number of radiographic exposures on a single film and to perform fluoroscopic examinations. To date, the spot film devices consist of two X-ray field defining masks, one of which is moved manually. The present device is more convenient to use and speeds up the procedure. (U.K.)

  5. X-ray microlaminography with polycapillary optics

    Energy Technology Data Exchange (ETDEWEB)

    Dabrowski, K. M.; Dul, D. T.; Wrobel, A.; Korecki, P. [Institute of Physics, Jagiellonian University, Reymonta 4, 30-059 Krakow (Poland)

    2013-06-03

    We demonstrate layer-by-layer x-ray microimaging using polycapillary optics. The depth resolution is achieved without sample or source rotation and in a way similar to classical tomography or laminography. The method takes advantage from large angular apertures of polycapillary optics and from their specific microstructure, which is treated as a coded aperture. The imaging geometry is compatible with polychromatic x-ray sources and with scanning and confocal x-ray fluorescence setups.

  6. Applications of soft x-ray lasers

    Energy Technology Data Exchange (ETDEWEB)

    Skinner, C.H.

    1993-08-01

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

  7. X-ray data booklet. Revision

    International Nuclear Information System (INIS)

    A compilation of data is presented. Included are properties of the elements, electron binding energies, characteristic x-ray energies, fluorescence yields for K and L shells, Auger energies, energy levels for hydrogen-, helium-, and neonlike ions, scattering factors and mass absorption coefficients, and transmission bands of selected filters. Also included are selected reprints on scattering processes, x-ray sources, optics, x-ray detectors, and synchrotron radiation facilities

  8. X-ray data booklet. Revision

    Energy Technology Data Exchange (ETDEWEB)

    Vaughan, D. (ed.)

    1986-04-01

    A compilation of data is presented. Included are properties of the elements, electron binding energies, characteristic x-ray energies, fluorescence yields for K and L shells, Auger energies, energy levels for hydrogen-, helium-, and neonlike ions, scattering factors and mass absorption coefficients, and transmission bands of selected filters. Also included are selected reprints on scattering processes, x-ray sources, optics, x-ray detectors, and synchrotron radiation facilities. (WRF)

  9. Novel optics for X-ray telescopes

    Czech Academy of Sciences Publication Activity Database

    Hudec, René; Pína, L.; Semencová, V.; Inneman, A.; Skulinová, Michaela; Nekola, Martin

    Berlin : Springer, 2009 - (Brandl, B.), s. 1-8 ISBN 978-90-481-2232-5. [400 Years of Astronomical Telescopes. Leiden (NL), 29.09.2008-02.10.2008] R&D Projects: GA AV ČR IAAX01220701; GA ČR GP202/07/P510 Institutional research plan: CEZ:AV0Z10030501 Keywords : X-ray telescopes * X-ray optics * X-ray astronomy Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  10. The X-ray emission of the gamma Cassiopiae stars

    CERN Document Server

    Smith, Myron A; Motch, C

    2015-01-01

    Long considered as the "odd man out" among X-ray emitting Be stars, \\gamma Cas (B0.5e\\,IV) is now recognized as the prototype of a class of stars that emit hard thermal X-rays. Our classification differs from the historical use of the term "gamma Cas stars" defined from optical properties alone. The luminosity output of this class contributes significantly to the hard X-ray production of massive stars in the Galaxy. The gamma Cas stars have light curves showing variability on a few broadly-defined timescales and spectra indicative of an optically thin plasma consisting of one or more hot thermal components. By now 9--13 Galactic \\approx B0-1.5e main sequence stars are judged to be members or candidate members of the \\gc\\ class. Conservative criteria for this designation are for a \\approxB0-1.5e III-V star to have an X-ray luminosity of 10^{32}--10^{33} ergs s^{-1}, a hot thermal spectrum containing the short wavelength Ly \\alpha FeXXV and FeXXVI lines and the fluorescence FeK feature all in emission. If therm...

  11. Synergistic approach to modeling X-ray spectra

    Energy Technology Data Exchange (ETDEWEB)

    Liedahl, D.A., LLNL

    1998-07-01

    Plasma emission models used in X-ray astronomy need to simulate X-ray spectra from at least thirteen elements. Development of comprehensive models requires large-scale calculations; for example, Fe M-shell spectra, K{alpha} fluorescence from near-neutral ions, and dielectronic recombination satellite spectra from L-shell ions. Current and recent missions (EUVE, ASCA, DXS, etc.) have already demonstrated the need for major, rapid improvements in spectral models. The high-resolution spectra to be acquired with the next generation of X- ray observatories (AXAF, XMM, Astro-E) promise to push spectral models to their limits. Essential to ensuring the quality of calculations used in spectral codes is corroboration in the laboratory, where controlled and precisely measured plasma conditions can be attained. To this end, we are capitalizing on a three-way synergistic relationship that links astrophysical observations, atomic modeling, and experiments using the LLNL Electron Beam Ion Trap (EBIT). After providing a brief orientation concerning the role of plasma emission models in X-ray astronomy, we discuss one example of this interplay.

  12. High-resolution x-ray analysis with multilayer gratings

    CERN Document Server

    Jonnard, Philippe; André, Jean-Michel; 10.1002/xrs.1128

    2013-01-01

    Periodic multilayers are nowadays widely used to perform x-ray analysis in the soft x-ray range (photon energy lower than 1 keV). However, they do not permit to obtain high-resolution spectra like natural or synthetic crystals. Thus, multilayers cannot resolve interferences between close x-ray lines. It has been shown and demonstrated experimentally that patterning a grating profile within a multilayer structure leads to a diffractive optics with improved resolving power. We illustrate the use of a Mo/B4C multilayer grating in the Fe L and C K spectral ranges, around 700 eV and 280 eV respectively. First, in the Fe L range, the improved spectral resolution enables us to distinguish the Fe L\\alpha and L\\beta emissions (separated by 13 eV). In addition, using a sample made of a mix of LiF and an iron ore, we show that it is possible to easily resolve the F K and Fe L emissions. These examples demonstrate that an improved x-ray analysis can be obtained with multilayer gratings when there is the need to study sam...

  13. X-ray emission from clusters of galaxies

    Science.gov (United States)

    Mushotzky, R. F.

    1984-01-01

    Some X-ray spectral observations of approximately 30 clusters of galaxies from HEAO-1 are summarized. There exists strong correlation betwen X-ray luminosity, L(x), and temperature kT in the form L(x)alphaT to the 2.3 power. This result combined with the L(x) central galaxy density relation and the virial theorem indicates that the core dadius of the gas should be roughly independent of L(x) or Kt and that more luminous clusters have a greater fraction of their virial mass in gas. The poor correlation of KT and optical velocity dispersion seems to indicate that clusters have a variety of equations of state. There is poor agreement between X-ray imaging observations and optical and X-ray spectral measures of the polytropic index. Most clusters show Fe emission lines with a strong indication that they all have roughly 1/2 solar abundance. The evidence for cooling in the cores several clusters is discussed based on spectral observations with the Einstein solid state spectrometer.

  14. X-ray transient AGN and galaxies

    OpenAIRE

    Grupe, D.

    2001-01-01

    X-ray transience is the most extreme form of variability observed in AGN or normal in-active galaxies. While factors of 2-3 on timescales of days to years are quite commen among AGN, X-ray transients appear only once and vanish from the X-ray sky years later. The ROSAT All-Sky Survey was the tool to discover these sources. X-ray transience in AGN or galaxies can be caused by dramatic changes in the accretion rate of the central black hole or by changes of the properties of the accretion disk.

  15. Microfabrication of hard x-ray lenses

    DEFF Research Database (Denmark)

    Stöhr, Frederik

    characterization details that cannot be obtained by other means. The respective x-ray techniques largely benefit from continuously improved x-ray sources, x-ray detectors and x-ray optics. For instance, some techniques aiming for structural investigation of poly-crystalline materials directly benefit from more...... by their potential for compact integration, which makes them cost-effective, easy to handle and stable on-axis optics. A Si-CRL comprises multiple bi-parabolic cylindrical cavities. The bi-parabolic patterns are defined lithographically and vertically transferred into the Si substrate using deep reactive ion etching...

  16. Advanced X-ray diffractive optics

    OpenAIRE

    Vila-Comamala, J.; Jefimovs, K.; Pilvi, T.; Ritala, M; Sarkar, S S; Solak, H H; Guzenko, V.A.; Stampanoni, M.; Marone, F.; J. Raabe; G. Tzvetkov; Fink, R H; Grolimund, D.; Borca, C.N.; Kaulich, B

    2009-01-01

    X-ray microscopy greatly bene�ts from the advances in x-ray optics. At the Paul Scherrer Institut, developments in x-ray di�ractive optics include the manufacture and optimization of Fresnel zone plates (FZPs) and di�ractive optical elements for both soft and hard x-ray regimes. In particular, we demonstrate here a novel method for the production of ultra-high resolution FZPs. This technique is based on the deposition of a zone plate material (iridium) onto the sidewalls of a p...

  17. Microscopic x-ray luminescence computed tomography

    Science.gov (United States)

    Zhang, Wei; Zhu, Dianwen; Zhang, Kun; Li, Changqing

    2015-03-01

    X-ray luminescence computed tomography (XLCT) was emerged as a new hybrid imaging modality, in which the x-rays are used to excite phosphors emitting optical photons to be measured for imaging. In this paper, we reported a microscopic x-ray luminescence computed tomography (microXLCT) with a spatial resolution up to hundreds of micrometers for deep targets. We use a superfine x-ray pencil beam to scan the phosphor targets. The superfine x-ray pencil beam is generated by a small collimator mounted in front of a powerful x-ray tube (93212, Oxford Instrument). A CT detector is used to image the x-ray beam. We have generated an x-ray beam with a diameter of 192 micrometers with a collimator of 100 micrometers in diameter. The emitted optical photons on the top surface of phantom are reflected by a mirror and acquired by an electron multiplier charge-coupled device (EMCCD) camera (C9100-13, Hamamatsu Photonics). The microXLCT imaging system is built inside an x-ray shielding and light tight cabinet. The EMCCD camera is placed in a lead box. All the imaging components are controlled by a VC++ program. The optical photon propagation is modeled with the diffusion equation solved by the finite element method. We have applied different regularization methods including L2 and L1 in the microXLCT reconstruction algorithms. Numerical simulations and phantom experiments are used to validate the microXLCT imaging system.

  18. Imaging with x-ray lasers

    Energy Technology Data Exchange (ETDEWEB)

    Da Silva, L.B.; Cauble, B.; Frieders, G.; Koch, J.A.; MacGowan, B.J.; Matthews, D.L.; Mrowka, S.; Ress, D.; Trebes, J.E.; Weiland, T.L.

    1993-11-01

    Collisionally pumped soft x-ray lasers now operate over a wavelength range extending from 35--300 {Angstrom}. These sources have high peak brightness and are now being utilized for x-ray imaging and plasma interferometry. In this paper we will describe our efforts to probe long scalelength plasmas using Moire deflectrometry and soft x-ray imaging. The progress in the development of short pulse x-ray lasers using a double pulse irradiation technique which incorporates a travelling wave pump will also be presented.

  19. X-ray Emission from Elliptical Galaxies

    OpenAIRE

    Sarazin, Craig L.

    1996-01-01

    Elliptical galaxies are generally luminous sources of X-ray radiation, and contain large amounts of hot, interstellar gas. In the brighter X-ray galaxies, the inferred masses of hot gas are consistent with those expected given the present rates of stellar mass loss. The required rates of heating of the gas are also roughly consistent with those expected from the motions of gas losing stars. X-ray observations, particularly X-ray spectra, require a low rate of Type Ia supernova heating and che...

  20. X-ray Observations of Planetary Nebulae

    OpenAIRE

    Guerrero, M. A.; Chu, Y.-H.; Gruendl, R A

    2003-01-01

    Planetary nebulae (PNe) are an exciting addition to the zoo of X-ray sources. Recent Chandra and XMM-Newton observations have detected diffuse X-ray emission from shocked fast winds in PN interiors as well as bow-shocks of fast collimated outflows impinging on the nebular envelope. Point X-ray sources associated with PN central stars are also detected, with the soft X-ray (>0.5 keV) emission from instability shocks in the fast stellar wind itself or from a low-mass companion's coronal activit...

  1. Hard X-ray Modulation Telescope

    Institute of Scientific and Technical Information of China (English)

    LU Fangjun

    2011-01-01

    The Hard X-ray Modulation Telescope (HXMT) will be China's first astronomical satellite. On board HXMT there are three kinds of slat-collimated telescopes, the High Energy X-ray Telescope (HE, 20-250 keV, 5000 cm^2), the Medium Energy X-ray Telescope (ME, 5-30 keV, 952 cm^2), and the Low Energy X-ray Telescope (LE, 1-15 keV, 384 cm^2).

  2. X-ray pulsar rush in 1998

    International Nuclear Information System (INIS)

    We present recent remarkable topics about discoveries of X-ray pulsars. 1. Pulsations from two Soft Gamma-ray Repeaters: These pulsars have enormously strong magnetic field (B ∼ 1015 G), thus these are called as 'magnetar', new type of X-ray pulsars. 2. New Crab-like pulsars: These discoveries lead to suggesting universality of Crab-like pulsars. 3. An X-ray bursting millisecond pulsar: This is strong evidence for the recycle theory of generating radio millisecond pulsars. 4. X-ray pulsar rush in the SMC: This indicates the younger star formation history in the SMC. (author)

  3. The Lunar X-ray Observatory (LXO)

    Science.gov (United States)

    Porter, F. Scott

    2008-01-01

    X-ray emission from charge exchange recombination between the highly ionized solar wind and neutral material i n Earth's magnetosheath has complicated x-ray observations of celestial objects with x-ray observatories including ROSAT, Chandra, XMM-Newton, and Suzaku. However, the charge-exchange emission can also be used as an important diagnostic of the solar-wind interacting with the magnetosheath. Soft x-ray observations from low-earth orbit or even the highly eccentric orbits of Chandra and XMM-Newton are likely superpositions of the celestial object of interest, the true extra-solar soft x-ray background, geospheric charge exchange, and heliospheric charge exchange. We show that with a small x-ray telescope placed either on the moon, in a similar vein as the Apollo ALSOP instruments, or at a stable orbit near L1, we can begin t o disentangle the complicated emission structure in the soft x-ray band. Here we present initial results of a feasibility study recently funded by NASA t o place a small x-ray telescope on the lunar surface. The telescope operates during lunar night to observe charge exchange interactions between the solar wind and magnetospheric neutrals, between the solar wind and the lunar atmosphere, and an unobstructed view of the soft x-ray background without the geospheric component.

  4. Ultrashort X-ray pulse science

    Energy Technology Data Exchange (ETDEWEB)

    Chin, Alan Hap [Univ. of California, Berkeley, CA (US). Dept. of Physics; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    1998-05-01

    A variety of phenomena involves atomic motion on the femtosecond time-scale. These phenomena have been studied using ultrashort optical pulses, which indirectly probe atomic positions through changes in optical properties. Because x-rays can more directly probe atomic positions, ultrashort x-ray pulses are better suited for the study of ultrafast structural dynamics. One approach towards generating ultrashort x-ray pulses is by 90{sup o} Thomson scattering between terawatt laser pulses and relativistic electrons. Using this technique, the author generated {approx} 300 fs, 30 keV (0.4 {angstrom}) x-ray pulses. These x-ray pulses are absolutely synchronized with ultrashort laser pulses, allowing femtosecond optical pump/x-ray probe experiments to be performed. Using the right-angle Thomson scattering x-ray source, the author performed time-resolved x-ray diffraction studies of laser-perturbated InSb. These experiments revealed a delayed onset of lattice expansion. This delay is due to the energy relaxation from a dense electron-hole plasma to the lattice. The dense electron-hole plasma first undergoes Auger recombination, which reduces the carrier concentration while maintaining energy content. Longitudinal-optic (LO) phonon emission then couples energy to the lattice. LO phonon decay into acoustic phonons, and acoustic phonon propagation then causes the growth of a thermally expanded layer. Source characterization is instrumental in utilizing ultrashort x-ray pulses in time-resolved x-ray spectroscopies. By measurement of the electron beam diameter at the generation point, the pulse duration of the Thomson scattered x-rays is determined. Analysis of the Thomson scattered x-ray beam properties also provides a novel means of electron bunch characterization. Although the pulse duration is inferred for the Thomson scattering x-ray source, direct measurement is required for other x-ray pulse sources. A method based on the laser-assisted photoelectric effect (LAPE) has

  5. X-ray pulsars: a review

    CERN Document Server

    Caballero, I

    2012-01-01

    Accreting X-ray pulsars are among the most luminous objects in the X-ray sky. In highly magnetized neutron stars (B~10^12 G), the flow of matter is dominated by the strong magnetic field. The general properties of accreting X-ray binaries are presented, focusing on the spectral characteristics of the systems. The use of cyclotron lines as a tool to directly measure a neutron star's magnetic field and to test the theory of accretion are discussed. We conclude with the current and future prospects for accreting X-ray binary studies.

  6. Ultrashort X-ray pulse science

    International Nuclear Information System (INIS)

    A variety of phenomena involves atomic motion on the femtosecond time-scale. These phenomena have been studied using ultrashort optical pulses, which indirectly probe atomic positions through changes in optical properties. Because x-rays can more directly probe atomic positions, ultrashort x-ray pulses are better suited for the study of ultrafast structural dynamics. One approach towards generating ultrashort x-ray pulses is by 90o Thomson scattering between terawatt laser pulses and relativistic electrons. Using this technique, the author generated ∼ 300 fs, 30 keV (0.4 (angstrom)) x-ray pulses. These x-ray pulses are absolutely synchronized with ultrashort laser pulses, allowing femtosecond optical pump/x-ray probe experiments to be performed. Using the right-angle Thomson scattering x-ray source, the author performed time-resolved x-ray diffraction studies of laser-perturbated InSb. These experiments revealed a delayed onset of lattice expansion. This delay is due to the energy relaxation from a dense electron-hole plasma to the lattice. The dense electron-hole plasma first undergoes Auger recombination, which reduces the carrier concentration while maintaining energy content. Longitudinal-optic (LO) phonon emission then couples energy to the lattice. LO phonon decay into acoustic phonons, and acoustic phonon propagation then causes the growth of a thermally expanded layer. Source characterization is instrumental in utilizing ultrashort x-ray pulses in time-resolved x-ray spectroscopies. By measurement of the electron beam diameter at the generation point, the pulse duration of the Thomson scattered x-rays is determined. Analysis of the Thomson scattered x-ray beam properties also provides a novel means of electron bunch characterization. Although the pulse duration is inferred for the Thomson scattering x-ray source, direct measurement is required for other x-ray pulse sources. A method based on the laser-assisted photoelectric effect (LAPE) has been

  7. X-rays pinpoint tumour targets

    International Nuclear Information System (INIS)

    When a surgeon in Birmingham used an X-ray photograph to guide the removal of a needle buried in a woman's hand in January 1896, it became the first X-ray guided operation in medical history. Since then X-rays have been widely used for medical imaging, and 'computed tomography' now provides us with exquisite 2D cross-sectional images of the human body. The technique creates images by passing X-rays along a plane through the body and recording the transmitted signals from various angles. A 'CT scan' lets us locate and visualize tumours with a resolution of 1 mm. But there is more to X-rays than imaging - they can also treat patients by killing cancerous tumours. When X-rays interact with tissue, they release highly reactive radicals that break the double strands in DNA molecules and cause the rapidly dividing cancerous cells to die. But because X-rays kill both healthy and diseased tissue in equal measure, it is vital to minimize the radiation received by healthy organs and tissue surrounding the tumour. The goal of radiotherapy is to find the precise location of a tumour using a CT scan - or other imaging technique - and then concentrate the X-rays on it to destroy the diseased tissue. In the August issue of Physics World Matin Durrani describes how intensity-modulated radiation therapy can deliver precise doses of X-rays to tumours while leaving surrounding, healthy tissue relatively unscathed. (U.K.)

  8. An X-ray image of the violent interstellar medium in 30 Doradus

    International Nuclear Information System (INIS)

    A detailed analysis of the X-ray emission from the largest H II region complex in the Local Group, 30 Dor, is presented. Applying a new maximum entropy deconvolution algorithm to the Einstein Observatory data, reveals striking correlations among the X-ray, radio, and optical morphologies of the region, with X-ray-emitting bubbles filling cavities surrounded by H-alpha shells and coextensive diffuse X-ray and radio continuum emission from throughout the region. The total X-ray luminosity in the 0.16-3.5 keV band from an area within 160 pc of the central cluster R136 is about 2 x 10 to the 37th ergs/sec. 53 refs

  9. X-ray imaging using a tunable coherent X-ray source based on parametric X-ray radiation

    International Nuclear Information System (INIS)

    A novel X-ray source based on parametric X-ray radiation (PXR) has been employed for X-ray imaging at the Laboratory for Electron Beam Research and Application (LEBRA), Nihon University. Notable features of PXR are tunable energy, monochromaticity with spatial chirp, narrow local bandwidth and spatial coherence. Since the X-ray beam from the PXR system has a large irradiation area with uniform flux density, the PXR-based source is suited for X-ray imaging, especially for application to phase-contrast imaging. Despite the cone-like X-ray beam, diffraction-enhanced imaging (DEI) can be employed as a phase contrast imaging technique. DEI experiments were performed using 14- to 34-keV X-rays and the phase-gradient images were obtained. The results demonstrated the capability of PXR as an X-ray source for phase-contrast imaging with a large irradiation field attributed to the cone-beam effect. Given the significant properties of the LEBRA-PXR source, the result suggests the possible construction of a compact linac-driven PXR-Imaging instrument and its application to medical diagnoses

  10. On the universal X-ray luminosity function of binary X-ray sources in galaxies

    OpenAIRE

    Postnov, K. A.

    2002-01-01

    The empirically determined universal power-law shape of X-ray luminosity function of high mass X-ray binaries in galaxies is explained by fundamental mass-luminosity and mass-radius relations for massive stars.

  11. Wide field x-ray telescopes: Detecting x-ray transients/afterglows related to GRBs

    International Nuclear Information System (INIS)

    The recent discovery of X-ray afterglows of GRBs opens the possibility of analyses of GRBs by their X-ray detections. However, imaging X-ray telescopes in current use mostly have limited fields of view. Alternative X-ray optics geometries achieving very large fields of view have been theoretically suggested in the 70's but not constructed and used so far. We review the geometries and basic properties of the wide-field X-ray optical systems based on one- and two-dimensional lobster-eye geometry and suggest technologies for their development and construction. First results of the development of double replicated X-ray reflecting flats for use in one-dimensional X-ray optics of lobster-eye type are presented and discussed. The optimum strategy for locating GRBs upon their X-ray counterparts is also presented and discussed

  12. Multicell X-ray detector

    International Nuclear Information System (INIS)

    A detector for X-radiation or other ionizing radiation is described comprising a pair of curved metal bars lying in spaced apart parallel planes. Ceramic members are bonded to the respective bars in facing relationship. Each ceramic member has a plurality of radially extending circumferentially spaced grooves facing similar grooves in the other member. A plurality of electrode plates are held in juxtaposed and circumferentially spaced apart relationship by disposing their respective upper and lower edges in the grooves of opposed ceramic members. The faces of adjacent electrode plates define gas-filled gaps in which photoelectron-ion pairs are produced when radiation enters from the front edges of the plates. The above described assembly is disposed within a pressurized gas-filled chamber having an X-ray transmissive window adjacent the front edges of the plates. A cover encloses the chamber. It has insulator feed-throughs for connecting the electrode plates with external electric circuits. Photoelectrons and/or ions, created by the ionizing radiation, are collected on the electrode plates and thereby generate an electrical signal which corresponds to the incident ionizing radiation. (Auth.)

  13. X-ray radiography facility

    International Nuclear Information System (INIS)

    The paper described a radiographic apparatus containing a radiation source, a diaphragm with collimating windows and a cassette holder with a cassette for the X-ray film. In order to increase the efficiency and quality of monitoring, the diaphragm and the cassette are made in the form of cylindrical shells, the centre of curvature of which coincides with the position of the radiation source focus. Each collimating window of the diaphragm is made in the form of two coaxially connected truncated cones, joined at the large bases in such a way that the angle at the vertex of the cone nearer the source is not less than the central angle with the vertex at the focus of the radiation source supported by the larger base, and 15-300 less than the angle at the vertex of the cone further from the source. By this means monitoring efficiency is increased by a factor of 1.5-2 and the quality of the radiographs improved. The apparatus is used for flaw detection in cylindrical objects. (author)

  14. Diffraction leveraged modulation of X-ray pulses using MEMS-based X-ray optics

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, Daniel; Shenoy, Gopal; Wang, Jin; Walko, Donald A.; Jung, Il-Woong; Mukhopadhyay, Deepkishore

    2016-08-09

    A method and apparatus are provided for implementing Bragg-diffraction leveraged modulation of X-ray pulses using MicroElectroMechanical systems (MEMS) based diffractive optics. An oscillating crystalline MEMS device generates a controllable time-window for diffraction of the incident X-ray radiation. The Bragg-diffraction leveraged modulation of X-ray pulses includes isolating a particular pulse, spatially separating individual pulses, and spreading a single pulse from an X-ray pulse-train.

  15. Lenses for Soft X-Rays and X-ray Microscopy Experiments

    International Nuclear Information System (INIS)

    This paper discusses the development of zone plates as x-ray lenses by the use of a uv-holographic lithography technique. Condenser zone plates as well as scanning x-ray microscopes are described. In addition, results of x-ray microscopy experiments are presented, which have been performed with an imaging x-ray microscope installed at the BESSY electron storage ring in Berlin

  16. X-ray topography and multiple diffraction

    International Nuclear Information System (INIS)

    A short summary on X-ray topography, which is based on the dynamical theory of X-ray diffraction, is made. The applications and properties related to the use of the multiple diffraction technique are analized and discussed. (L.C.)

  17. Proton induced X-ray emission analysis

    International Nuclear Information System (INIS)

    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

  18. Rotatable target for x-ray tubes

    International Nuclear Information System (INIS)

    Distorsion of the focal trace results in reduction of X-ray intensity, which may stop the desired use of the X-ray tube early. This distorsion can be avoided almost by use of molybdenum alloys for base body and substrate. Different alloys together with belonging measured values are described. (J.K.)

  19. X-ray diagnosis in birds

    International Nuclear Information System (INIS)

    The author describes techniques of X- ray examination in birds and the advantages of using contrast medium. He gives the medical indications of such examinations and lists the main anatomical features to be well known in birds for a better interpretation of X-ray pictures

  20. X-ray spectroscopy of magnetic CVs

    Science.gov (United States)

    Matt, Giorgio

    I discuss two topics in X-ray spectroscopy of magnetic CVs: reflection from the white dwarf surface, and opacity effects in the post shock plasma. I also briefly mention future observational perspectives, with particular emphasis on the Constellation X-ray mission.

  1. Tracing the X-Ray Trail

    Science.gov (United States)

    What you need to know about… Tracing the X-ray Trail If you’ve just completed an x-ray, computed tomography (CT), magnetic resonance (MR) Start here! or other diagnostic imaging procedure, you probably want to know when you will ... los rayos X Si acaba de hacerse una radiografía, tomografía ¡Empezar ...

  2. Coccidioidomycosis - chest x-ray (image)

    Science.gov (United States)

    This chest x-ray shows the affects of a fungal infection, coccidioidomycosis. In the middle of the left lung (seen on the ... defined borders. Other diseases that may explain these x-ray findings include lung abscesses, chronic pulmonary tuberculosis, chronic ...

  3. X-ray diagnosis of retropatellar diseases

    International Nuclear Information System (INIS)

    The article reports on a comprehensive, stepwise diagnosis in diseases of the knee joints. This includes a description of the indication, the technique of taking X-ray films, and X-ray findings, as well as arthrography of the femoropatellar joint in retropatellar diseases such as chondropathia patellae, osteochondrosis dissecans, traumas of the knee joints and arthrosis deformans. (orig.)

  4. Adenocarcinoma - chest x-ray (image)

    Science.gov (United States)

    This chest x-ray shows adenocarcinoma of the lung. There is a rounded light spot in the right upper lung (left side ... density. Diseases that may cause this type of x-ray result would be tuberculous or fungal granuloma, and ...

  5. X-Ray Detection Visits the Classroom

    Science.gov (United States)

    Peralta, Luis; Farinha, Ana; Pinto, Ana

    2008-01-01

    Film has been used to detect x-rays since the early days of their discovery by Rontgen. Although nowadays superseded by other techniques, film still provides a cheap means of x-ray detection, making it attractive in high-school or undergraduate university courses. If some sort of quantitative result is required, the film's optical absorbance or…

  6. Soft x rays for radiobiological studies

    International Nuclear Information System (INIS)

    Lethal effects and chromosome aberrations induced in cells exposed to low energy (soft) X rays demonstrated that these relatively low energy X rays are just as effective as those of higher energy for radiobiological studies, and even more effective for irradiating cultured mammalian cells than laboratory animals. (author)

  7. X-Ray Exam: Scoliosis (For Parents)

    Science.gov (United States)

    ... Your Child All About Food Allergies X-Ray Exam: Scoliosis KidsHealth > For Parents > X-Ray Exam: Scoliosis Print A A A Text Size What's ... routinely check kids for scoliosis during regular physical exams, and some schools also test for scoliosis. If ...

  8. Large X-ray optics: lobster alternative

    Czech Academy of Sciences Publication Activity Database

    Hudec, René; Pína, L.; Inneman, A.

    Garching : MaxPlanck Institute for Extraterrestrial Physics, 2003 - (Hasinger, G.; Boller, T.; Parmer, A.), s. 271-277 [XEUS - studying the evolution of the hot Universe. Garching (DE), 11.03.2002-13.03.2002] Institutional research plan: CEZ:AV0Z1003909 Keywords : XEUS X-ray telescope * lobster eye X-ray optics Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  9. Accelerator-driven X-ray Sources

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Dinh Cong [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-11-09

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

  10. X-ray scattering measurements from thin-foil x-ray mirrors

    DEFF Research Database (Denmark)

    Christensen, Finn Erland; BYRNAK, BP; Hornstrup, Allan;

    1992-01-01

    Thin foil X-ray mirrors are to be used as the reflecting elements in the telescopes of the X-ray satellites Spectrum-X-Gamma (SRG) and ASTRO-D. High resolution X-ray scattering measurements from the Au coated and dip-lacquered Al foils are presented. These were obtained from SRG mirrors positioned...

  11. Soft X-Ray Spectra of AGN Discovered Via Their Hard X-Ray

    Science.gov (United States)

    Schwartz, Daniel

    1998-01-01

    This final report is a study of the Active Galactic Nuclei (AGN). Investigation of the soft x-ray spectra of AGN were performed by using their hard x-ray emission. ROSAT observations of AGN was also performed, which allowed for the study of these x-ray spectra and the structures of 7 clusters of galaxies.

  12. X-ray devices contributing to sophistication of X-ray diagnostic systems

    International Nuclear Information System (INIS)

    X-ray tubes to generate X-rays, as well as X-ray image intensifiers (I.I.s) and X-ray flat panel detectors (FPDs) to convert X-ray images into electronic signals, are key devices in X-ray diagnostic systems, which are playing a major role in the advancement of diagnosis and treatment. Toshiba Electron Tubes and Devices Co., Ltd. has been offering optimal products incorporating the most advanced technologies to customers through continuous technological innovations. These include a high-sensitivity technology for X-ray I.I.s and X-ray FPDs to suppress patient exposure doses, a focal spot design technology for X-ray tubes and high-resolution technologies for X-ray I.I.s and X-ray FPDs that enhance image quality and make it possible to detect smaller lesion areas, and a noise reduction technology for X-ray tubes to realize a comfortable medical environment with reduced stress on both patients and medical staff. (author)

  13. X-Ray Synchrotron Emitting Fe-Rich Ejecta in SNR RCW 86

    CERN Document Server

    Rho, J; Borkowski, K J; Reynolds, S P; Rho, Jeonghee; Dyer, Kristy K.; Borkowski, Kazimierz J.; Reynolds, Stephen P

    2002-01-01

    Supernova remnants may exhibit both thermal and nonthermal X-ray emission. We present Chandra observations of RCW 86. Striking differences in the morphology of X-rays below 1 keV and above 2 keV point to a different physical origin. Hard X-ray emission is correlated fairly well with the edges of regions of radio emission, suggesting that these are the locations of shock waves at which both short-lived X-ray emitting electrons, and longer-lived radio-emitting electrons, are accelerated. Soft X-rays are spatially well-correlated with optical emission from nonradiative shocks, which are almost certainly portions of the outer blast wave. These soft X-rays are well fit with simple thermal plane-shock models. Harder X-rays show Fe K alpha emission and are well described with a similar soft thermal component, but a much stronger synchrotron continuum dominating above 2 keV, and a strong Fe K alpha line. Quantitative analysis of this line and the surrounding continuum shows that it cannot be produced by thermal emiss...

  14. On the Absorption of X-ray Bright Broad Absorption Line Quasars

    CERN Document Server

    Giustini, Margherita; Vignali, Cristian

    2008-01-01

    Most X-ray studies of BALQSOs found significant (N_H~10^{22-24} cm^{-2}) intrinsic column densities of gas absorbing an underlying typical power-law continuum emission, in agreement with expectations from radiatively driven accretion disk wind models. However, direct spectral analysis was performed only on a limited number of bright sources. We investigate the X-ray emission of a large BALQSO sample at medium to high redshift (0.8 ~ 5 x 10^{22} cm^{-2}) even including the faintest sources analyzed through hardness ratio analysis. The mean photon index is Gamma~1.9, with no significant evolution with redshift. The alpha_ox are typical of radio-quiet broad line AGN, in contrast with the known (from previous X-ray studies) ``soft X-ray weakness'' of BALQSOs and in agreement with the lack of X-ray absorption. We found the low-Absorption Index (AI) subsample to host the lowest X-ray absorbing column densities of the entire sample. X-ray selected BALQSOs show lower X-ray absorption than purely optically selec ted o...

  15. An X-ray Imaging Survey of Quasar Jets -- Testing the Inverse Compton Model

    CERN Document Server

    Marshall, H L; Schwartz, D A; Murphy, D W; Lovell, J E J; Worrall, D M; Birkinshaw, M; Perlman, E S; Godfrey, L; Jauncey, D L

    2011-01-01

    We present results from continued Chandra X-ray imaging and spectroscopy of a flux-limited sample of flat spectrum radio-emitting quasars with jet-like extended structure. X-rays are detected from 24 of the 39 jets observed so far. We compute the distribution of alpha_rx, the spectral index between the X-ray and radio bands, showing that it is broad, extending at least from 0.8 to 1.2. While there is a general trend that the radio brightest jets are detected most often, it is clear that predicting the X-ray flux from the radio knot flux densities is risky so a shallow X-ray survey is the most effective means for finding jets that are X-ray bright. We test the model in which the X-rays result from inverse Compton (IC) scattering of cosmic microwave background (CMB) photons by relativistic electrons in the jet moving with high bulk Lorentz factor nearly along the line of sight. Depending on how the jet magnetic fields vary with z, the observed X-ray to radio flux ratios do not follow the redshift dependence exp...

  16. X-ray cycles and magnetic activity of solar-like stars

    Science.gov (United States)

    Robrade, J.

    2016-06-01

    Since the beginning of its operation XMM-Newton carries out a monitoring program to study coronal cyclic behavior in stars similar to our Sun. I present highlights and recent results from the X-ray monitoring campaign, that observes neighboring stellar systems like Alpha Centauri and 61 Cygni. Cyclic activity phenomena and coronal properties are discussed and put into context of X-ray emission from the Sun and solar-type stars. As an outlook, future perspectives of stellar X-ray studies with a focus on the eROSITA all-sky survey are presented.

  17. High Energy Vision: Processing X-rays

    CERN Document Server

    DePasquale, Joseph; Edmonds, Peter

    2015-01-01

    Astronomy is by nature a visual science. The high quality imagery produced by the world's observatories can be a key to effectively engaging with the public and helping to inspire the next generation of scientists. Creating compelling astronomical imagery can, however, be particularly challenging in the non-optical wavelength regimes. In the case of X-ray astronomy, where the amount of light available to create an image is severely limited, it is necessary to employ sophisticated image processing algorithms to translate light beyond human vision into imagery that is aesthetically pleasing while still being scientifically accurate. This paper provides a brief overview of the history of X-ray astronomy leading to the deployment of NASA's Chandra X-ray Observatory, followed by an examination of the specific challenges posed by processing X-ray imagery. The authors then explore image processing techniques used to mitigate such processing challenges in order to create effective public imagery for X-ray astronomy. ...

  18. Requirements for industrial x-ray equipment

    International Nuclear Information System (INIS)

    This safety code is concerned with the protection of all individuals who may be exposed to radiation emitted by X-ray equipment operating at energies up to 1 MeV as used in industrial radiography. This code presents basic radiation safety information for the protection of personnel operating and servicing X-ray equipment and other workers and the general public in the vicinity of areas where X-ray equipment is in operation. It specifies general safety features of design, construction and functioning of X-ray equipment and facilities; describes the responsibilities of the user, operator and maintenance personnel; contains recommendations to ensure that the X-ray equipment is used and maintained in accordance with the ALARA principle; and describes a program of personnel monitoring and radiation safety surveys. ( 6 refs., 5 tabs., 4 figs.)

  19. Development of coherent x-ray lasers

    International Nuclear Information System (INIS)

    Proposed x-ray laser applications such as interferometry and holography require coherent radiation. The fact that x-ray laser media are short-lived high-temperature plasmas leads to very different coherence properties from those of ordinary lasers. Research aimed at developing theoretical models and experimentally characterizing and improving x-ray laser coherence is discussed. Longitudinal coherence is already sufficient for several applications due to the narrow linewidths. However, transverse coherence is estimated to be poor for most current x-ray lasers. To quantify these estimates and to design better lasers, both wave and geometric optics propagation and coherence theories have been developed. These theories and resulting predictions of the coherence length are presented and compared. Measurements of x-ray laser beam patterns and coherence lengths are presented and compared to detailed theoretical simulations. Designs for more coherent lasers are given

  20. Perspectives of medical X-ray imaging

    Science.gov (United States)

    Freudenberger, J.; Hell, E.; Knüpfer, W.

    2001-06-01

    While X-ray image intensifiers (XII), storage phosphor screens and film-screen systems are still the work horses of medical imaging, large flat panel solid state detectors using either scintillators and amorphous silicon photo diode arrays (FD-Si), or direct X-ray conversion in amorphous selenium are reaching maturity. The main advantage with respect to image quality and low patient dose of the XII and FD-Si systems is caused by the rise of the Detector Quantum Efficiency originating from the application of thick needle-structured phosphor X-ray absorbers. With the detectors getting closer to an optimal state, further progress in medical X-ray imaging requires an improvement of the usable source characteristics. The development of clinical monochromatic X-ray sources of high power would not only allow an improved contrast-to-dose ratio by allowing smaller average photon energies in applications but would also lead to new imaging techniques.

  1. Perspectives of medical X-ray imaging

    International Nuclear Information System (INIS)

    While X-ray image intensifiers (XII), storage phosphor screens and film-screen systems are still the work horses of medical imaging, large flat panel solid state detectors using either scintillators and amorphous silicon photo diode arrays (FD-Si), or direct X-ray conversion in amorphous selenium are reaching maturity. The main advantage with respect to image quality and low patient dose of the XII and FD-Si systems is caused by the rise of the Detector Quantum Efficiency originating from the application of thick needle-structured phosphor X-ray absorbers. With the detectors getting closer to an optimal state, further progress in medical X-ray imaging requires an improvement of the usable source characteristics. The development of clinical monochromatic X-ray sources of high power would not only allow an improved contrast-to-dose ratio by allowing smaller average photon energies in applications but would also lead to new imaging techniques

  2. Perspectives of medical X-ray imaging

    Energy Technology Data Exchange (ETDEWEB)

    Freudenberger, J. E-mail: joerg.freudenberger@med.siemens.de; Hell, E.; Knuepfer, W

    2001-06-21

    While X-ray image intensifiers (XII), storage phosphor screens and film-screen systems are still the work horses of medical imaging, large flat panel solid state detectors using either scintillators and amorphous silicon photo diode arrays (FD-Si), or direct X-ray conversion in amorphous selenium are reaching maturity. The main advantage with respect to image quality and low patient dose of the XII and FD-Si systems is caused by the rise of the Detector Quantum Efficiency originating from the application of thick needle-structured phosphor X-ray absorbers. With the detectors getting closer to an optimal state, further progress in medical X-ray imaging requires an improvement of the usable source characteristics. The development of clinical monochromatic X-ray sources of high power would not only allow an improved contrast-to-dose ratio by allowing smaller average photon energies in applications but would also lead to new imaging techniques.

  3. Origin of the X-ray disc-reflection steep radial emissivity

    OpenAIRE

    Svoboda, Jiří; Dovčiak, Michal; Goosmann, René W.; Jethwa, Prashin; Karas, Vladimír; Miniutti, Giovanni; Guainazzi, Matteo

    2012-01-01

    X-ray reflection off the accretion disc surrounding a black hole, together with the associated broad iron K$\\alpha$ line, has been widely used to constrain the innermost accretion-flow geometry and black hole spin. Some recent measurements have revealed steep reflection emissivity profiles in a number of active galactic nuclei and X-ray binaries. We explore the physically motivated conditions that give rise to the observed steep disc-reflection emissivity profiles. We perform a set of simulat...

  4. Picosecond time-resolved laser pump/X-ray probe experiments using a gated single-photon-counting area detector

    DEFF Research Database (Denmark)

    Ejdrup, T.; Lemke, H.T.; Haldrup, Martin Kristoffer; Nielsen, T.N.; Arms, D.A.; Walko, D.A.; Miceli, A.; Landahl, E.C.; Dufresne, E.M.; Nielsen, Martin Meedom

    capability of the gated PILATUS detector to selectively detect the signal from a given X-ray pulse in 24 bunch mode at the APS storage ring is demonstrated. A test experiment performed on polycrystalline organic thin films of [alpha]-perylene illustrates the possibility of reaching an X-ray pulse duration...

  5. X-ray reflection in oxygen-rich accretion discs of ultra-compact X-ray binaries

    CERN Document Server

    Madej, O K; Jonker, P G; Parker, M L; Ross, R; Fabian, A C; Chenevez, J

    2014-01-01

    We present spectroscopic X-ray data of two candidate ultra-compact X-ray binaries: 4U~0614+091 and 4U~1543$-$624. We confirm the presence of a broad O VIII Ly$\\alpha$ reflection line (at $\\approx18\\ \\AA$) using {\\it XMM-Newton} and {\\it Chandra} observations obtained in 2012 and 2013. The donor star in these sources is carbon-oxygen or oxygen-neon-magnesium white dwarf. Hence, the accretion disc is enriched with oxygen which makes the O VIII Ly$\\alpha$ line particularly strong. We also confirm the presence of a strong absorption edge at $\\approx14$ \\AA\\ so far interpreted in the literature as due to absorption by neutral neon in the circumstellar and interstellar medium. However, the abundance required to obtain a good fit to this edge is $\\approx3-4$ times solar, posing a problem for this interpretation. Furthermore, modeling the X-ray reflection off a carbon and oxygen enriched, hydrogen and helium poor disc with models assuming solar composition likely biases several of the best-fit parameters. In order to...

  6. Copper L X-ray spectra measured by a high resolution ion-induced X-ray spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Ryohei; Hamaguchi, Dai; Kageyama, Hiroyoshi [Kyoto Inst. of Tech. (Japan)] [and others

    1997-03-01

    High resolution L X-ray emission spectra of Cu have been measured by 0.75 MeV/u H, He, and F, 0.73 MeV/u Ar, 0.64 MeV/u Si, and 0.073 MeV/u Si ion impacts with a crystal spectrometer. The X-ray transition energies in the Cu target for L{iota}, L{eta}, L{alpha}{sub 1,2}, L{beta}{sub 1}, and L{beta}{sub 3,4} diagram lines induced by light ion impacts are determined, which are in good agreement with those given in the reference. The difference in L X-ray emission spectra produced by H, He, F, Si, and Ar ions are considered and the L{alpha}{sub 1,2} and L{beta}{sub 1} emission spectra are compared with the calculated ones based on the multiconfiguration Dirac-Fock method. (author)

  7. MEASURING OF X-RAY SOURCE SIZE BY USING COMPOUND REFRACTIVE X-RAY LENS

    Directory of Open Access Journals (Sweden)

    Yu. V. Dudchik

    2015-04-01

    Full Text Available Compound refractive lens was used for measuring size of 2-3 beamline Standford synchrotron radiation source and a size of microfocus X-ray tube. X-ray beam from the source was focused by the lens and parameters of the beam at image plane were measured. Scanning diaphragm and X-ray CCD-camera were used for measuring X-ray beam. It was found that the vertical size of synchrotron source is equal to 0,6 mm and the size of the X-ray tube focal spot is equal to 60 micrometers. 

  8. Large area soft x-ray collimator to facilitate x-ray optics testing

    Science.gov (United States)

    Espy, Samuel L.

    1994-01-01

    The first objective of this program is to design a nested conical foil x-ray optic which will collimate x-rays diverging from a point source. The collimator could then be employed in a small, inexpensive x-ray test stand which would be used to test various x-ray optics and detector systems. The second objective is to demonstrate the fabrication of the x-ray reflectors for this optic using lacquer-smoothing and zero-stress electroforming techniques.

  9. First X-ray fluorescence CT experimental results at the SSRF X-ray imaging beamline

    Institute of Scientific and Technical Information of China (English)

    DENG Biao; YANG Qun; XIE Hong-Lan; DU Guo-Hao; XIAO Wi-Qiao

    2011-01-01

    X-ray fluorescence CT is a non-destructive technique for detecting elemental composition and distribution inside a specimen. In this paper, the first experimental results of X-ray fluorescence CT obtained at the SSRF X-ray imaging beamline (BL13W1) are described. The test samples were investigated and the 2D elemental image was reconstructed using a filtered back-projection algorithm. In the sample the element Cd was observed. Up to now, the X-ray fluorescence CT could be carried out at the SSRF X-ray imaging beamline.

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

    OpenAIRE

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

    2015-01-01

    We describe a laser-driven x-ray plasma source designed for ultrafast x-ray absorption spectroscopy. The source is comprised of a 1 kHz, 20 W, femtosecond pulsed infrared laser and a water target. We present the x-ray spectra as a function of laser energy and pulse duration. Additionally, we investigate the plasma temperature and photon flux as we vary the laser energy. We obtain a 75 μm FWHM x-ray spot size, containing ∼106 photons/s, by focusing the produced x-rays with a polycapillary opti...

  11. X-ray Spectral Variation of Eta Carinae through the 2003 X-ray Minimum

    OpenAIRE

    Hamaguchi, Kenji; Corcoran, Michael F.; Gull, Theodore; Ishibashi, Kazunori; Pittard, Julian M.; Hillier, D. John; Damineli, Augusto; Davidson, Kris; Nielsen, Krister E.; Kober, Gladys Vieira

    2007-01-01

    We report the results of an X-ray observing campaign on the massive, evolved star Eta Carinae, concentrating on the 2003 X-ray minimum as seen by the XMM-Newton observatory. These are the first spatially-resolved X-ray monitoring observations of the stellar X-ray spectrum during the minimum. The hard X-ray emission, believed to be associated with the collision of Eta Carinae's wind with the wind from a massive companion star, varied strongly in flux on timescales of days, but not significantl...

  12. Common Envelope Mechanisms: Constraints from the X-ray Luminosity Function of High Mass X-ray Binaries

    CERN Document Server

    Zuo, Zhao-Yu

    2013-01-01

    We use the measured X-ray luminosity function (XLF) of high-mass X-ray binaries (HMXBs) to constrain the common envelope (CE) mechanisms, which usually serve as a key process governing the binary evolution. We show that the XLF can be reproduced quite closely under the canonical energy budget approach for CE evolution, while the angular momentum budget approach seems to predict HMXB population about 1 to 2 orders of magnitude greater than observed. In addition, the value of $\\alpha_{\\rm CE}$ can be constrained to be within about 0.5-1.0. We present the detailed components of the HMXB populations under the angular momentum budget approach and compare them with those in Zuo et al. and observations. We suggest the distinct observational properties, as well as period distributions of HMXBs may provide further clues to discriminate between these two types of CE mechanisms.

  13. On the relationship between circumstellar disc size and X-ray outbursts in Be/X-ray binaries

    CERN Document Server

    Monageng, Itumeleng M; Coe, Malcolm J; Steele, Iain A; Reig, Pablo

    2016-01-01

    We present long term H$\\alpha$ monitoring results of five Be/X-ray binaries to study the Be disc size variations and their influence on Type II (giant) X-ray outbursts. The work is done in the context of the viscous decretion disc model which predicts that Be discs in binary systems are truncated by resonant torques induced by the neutron star in its orbit. Our observations show that type II outbursts are not correlated(nor anti-correlated) with the disc size, as they are seen to occur both at relatively small and large Be disc radii. We discuss these observations in context of alternate interpretation of Be disc behaviour, such as precession, elongation and density effects, and with cognisance of the limitations of our disc size estimates.

  14. Dual-energy X-ray CT and the extension to polychromatic X-ray CT

    International Nuclear Information System (INIS)

    We have developed dual energy X-ray CT using monochromatic X-ray beams. From the dual-energy X-ray CT, we can obtain distributions of an electron density and an effective atomic number in a human body. Especially, the electron density is very important for the heavy ion radiotherapy. Now, we adopted new array-detector to know the energy of incident photons as well as detect the position and the number of photons. We carry out the experiment of the dual-energy X-ray CT at the beamline of KEK and SPring-8 as a fundamental study for the polychromatic X-ray CT. We will show the preliminary result of this experiments and the feasibility of a quantitative polychromatic X-ray CT as an advanced method of monochromatic X-ray CT in this study. (author)

  15. Toward Adaptive X-Ray Telescopes

    Science.gov (United States)

    O'Dell, Stephen L.; Atkins, Carolyn; Button, Tim W.; Cotroneo, Vincenzo; Davis, William N.; Doel, Peer; Feldman, Charlotte H.; Freeman, Mark D.; Gubarev, Mikhail V.; Kolodziejczak, Jeffrey J.; Michette, Alan G.; Ramsey, Brian D.; Reid, Paul B.; Rodriguez Sanmartin, Daniel; Saha, Timo T.; Schwartz, Daniel A.; Trolier-McKinstry, Susan; Wilke, Rudeger H. T.; Willingale, Richard; Zhang, William W.

    2011-01-01

    Future x-ray observatories will require high-resolution (less than 1 inch) optics with very-large-aperture (greater than 25 square meter) areas. Even with the next generation of heavy-lift launch vehicles, launch-mass constraints and aperture-area requirements will limit the surface areal density of the grazing-incidence mirrors to about 1 kilogram per square meter or less. Achieving sub-arcsecond x-ray imaging with such lightweight mirrors will require excellent mirror surfaces, precise and stable alignment, and exceptional stiffness or deformation compensation. Attaining and maintaining alignment and figure control will likely involve adaptive (in-space adjustable) x-ray optics. In contrast with infrared and visible astronomy, adaptive optics for x-ray astronomy is in its infancy. In the middle of the past decade, two efforts began to advance technologies for adaptive x-ray telescopes: The Generation-X (Gen-X) concept studies in the United States, and the Smart X-ray Optics (SXO) Basic Technology project in the United Kingdom. This paper discusses relevant technological issues and summarizes progress toward adaptive x-ray telescopes.

  16. Toward active x-ray telescopes

    Science.gov (United States)

    O'Dell, Stephen L.; Atkins, Carolyn; Button, Timothy W.; Cotroneo, Vincenzo; Davis, William N.; Doel, Peter; Feldman, Charlotte H.; Freeman, Mark D.; Gubarev, Mikhail V.; Kolodziejczak, Jeffery J.; Michette, Alan G.; Ramsey, Brian D.; Reid, Paul B.; Rodriguez Sanmartin, Daniel; Saha, Timo T.; Schwartz, Daniel A.; Trolier-McKinstry, Susan; Wilke, Rudeger H. T.; Willingale, Richard; Zhang, William W.

    2011-09-01

    Future x-ray observatories will require high-resolution ( 25 m2) areas. Even with the next generation of heavy-lift launch vehicles, launch-mass constraints and aperture-area requirements will limit the areal density of the grazing-incidence mirrors to about 1 kg/m2 or less. Achieving sub-arcsecond x-ray imaging with such lightweight mirrors will require excellent mirror surfaces, precise and stable alignment, and exceptional stiffness or deformation compensation. Attaining and maintaining alignment and figure control will likely involve active (in-space adjustable) x-ray optics. In contrast with infrared and visible astronomy, active optics for x-ray astronomy is in its infancy. In the middle of the past decade, two efforts began to advance technologies for adaptive x-ray telescopes: The Smart X-ray Optics (SXO) Basic Technology project in the United Kingdom (UK) and the Generation-X (Gen-X) concept studies in the United States (US). This paper discusses relevant technological issues and summarizes progress toward active x-ray telescopes.

  17. Stellar coronas, X-rays, and Einstein

    International Nuclear Information System (INIS)

    Observations of the sun at ultraviolet and X-ray wavelengths reveal a structure connected with the configuration of the solar magnetic field. The Einstein Observatory (HEAO 2), the first satellite to use an imaging X-ray telescope, searched for faint coronas on the basis of visual brightness and their proximity to the sun. Observed temperatures of transition regions between the chromosphere and the corona exceed 1,000,000 K. A possible correlation between X-ray luminosity and rotation rate has been observed and Einstein observations also indicated that stellar coronas showed changes in X-ray brightness during the most stable period of a star's life. Solar flares and transients, which generate substantial amounts of X-rays, radio waves and charged particles, are believed to be other properties of stellar coronas which change with age. Future missions such as NASA's Extreme Ultraviolet Explorer, the Advanced X-ray Astrophysics Facility and Space Telescope will enable astronomers to greatly increase their sampling of stellar coronas available for study. Observations also suggest the early development of a strong stellar dynamo due to X-ray activity in pre-main-sequence objects. It is hoped that the study of activity cycles in other stars will yield a greater understanding of the dynamo theory

  18. Cell survival studies using ultrasoft x rays

    International Nuclear Information System (INIS)

    Cell survival was studied for V79 hamster, 10T1/2 mouse, and human skin fibroblast cell lines, using carbon K (0.28 keV), copper K (8.0 keV), and 250 kVp x rays. Because of the rapid attenuation of the carbon x rays, cellular dimensions at the time of exposure were measured using optical and electron microscopy, and frequency distributions of mean dose absorbed by the cell nucleus were obtained. The results indicate that the differences in cell killing between ultra-soft and hard x rays may depend on the nuclear thickness of the cells. Studies of the effects of hypoxia on V79 and 10T1/2 cells using carbon K, aluminum K (1.5 keV), and copper K x rays show decreasing OER values with decreasing x-ray energy and no difference between the two cell lines. Age response studies with V79 cells show similar cell-cycle variation of survival for carbon K and aluminum K x rays as for hard x rays

  19. X-ray diffraction imaging and analysis

    International Nuclear Information System (INIS)

    The first papers dealing with the very important application of x-ray diffraction to crystal structure analysis were also published in 1912 by W.L. Bragg, while a student at Cambridge. Bragg performed an analysis of the Laue diffraction pattern of zinc blend and determined the correct structure of the crystal lattice. There have been many practical applications for x-ray diffraction techniques. Historically conventional x-ray machines were used as generators and film used as the recording medium. Prior to 1966, all attempts to directly image x-ray diffraction patterns used a large format x-ray image intensifier tube of the same type as conventionally used for medical and industrial fluoroscopy. Since the 1960's numerous electro-optical systems have been developed which are far better suited for real-time viewing and recording of x-ray diffraction patterns. Modern x-ray diffraction imaging systems incorporating rotating anode and pulsed x-ray generators, synchrotron x-ray sources, and optimized electro-optical systems have been used to orient single crystals, to study crystal lattice rotation accompanying plastic deformation, to measure the rate of grain boundary migration during recrystallization annealing of cold-worked metals, to determine the physical state of exploding metals, to rapidly measure residual stress (strain), to study the dynamics of structural phase transitions in ferroelectric crystals, to monitor the amorphous to crystalline phase transformation of rapidly solidified metals, and to record topographic images of lattice defects in quartz, gallium arsenide and nickel alloy turbine blade crystals

  20. X-ray hazards - diagnostic and therapeutic

    International Nuclear Information System (INIS)

    The subject is covered in sections, entitled: introduction; nature of X-rays; X-rays - effect on biological materials; X-ray measurement; radiation dosages to exposed groups; organizational structure of radiological protection; duties of the Radiological Safety Officer; general measures for radiological protection; protection of staff; protection of patients; safety measures in radiotherapy work - sealed sources laboratory -general safety rules; radiotherapy - duties of the Radiological Safety Officer (Radiotherapy); the custodian of sealed sources -duties and relevant radiological protection information; external beam therapy - radionuclide source unit - emergency procedure in the event of technical failure; safety aspects of brachytherapy in the patient's vicinity; diagnostic radiology; conclusion. (U.K.)

  1. X-ray microscopy using synchrotron radiation

    International Nuclear Information System (INIS)

    The system for x-ray microscopy now being developed at the X-26 beam line of the Brookhaven National Synchrotron Light Source (NSLS) is described here. Examples of the use of x-ray microscopy for trace element geochemistry, biology and medicine, and materials investigations are given to emphasize the scientific applications of the technique. Future directions for the improvement and further development of the X-26 microscope and of the x-ray microscopy field in general are discussed. 11 refs., 7 figs

  2. Two-dimensional x-ray diffraction

    CERN Document Server

    He, Bob B

    2009-01-01

    Written by one of the pioneers of 2D X-Ray Diffraction, this useful guide covers the fundamentals, experimental methods and applications of two-dimensional x-ray diffraction, including geometry convention, x-ray source and optics, two-dimensional detectors, diffraction data interpretation, and configurations for various applications, such as phase identification, texture, stress, microstructure analysis, crystallinity, thin film analysis and combinatorial screening. Experimental examples in materials research, pharmaceuticals, and forensics are also given. This presents a key resource to resea

  3. X-ray Variability of Blazars

    OpenAIRE

    Pian, Elena

    2002-01-01

    Critical progress in our understanding of high energy emission from AGN has been determined in the last 10 years by X-ray monitoring campaigns with many space missions, notably ROSAT, ASCA, RXTE, BeppoSAX, and XMM, often in conjunction with observations at other frequencies. The emphasis of the present review is on recent findings about X-ray variability of blazars. Among AGN, these exhibit the largest amplitude variations of the X-ray emission, often well correlated with variations at higher...

  4. Imaging Cellular Architecture with X-rays

    OpenAIRE

    Larabell, Carolyn A.; Nugent, Keith A.

    2010-01-01

    X-ray imaging of biological samples is progressing rapidly. In this paper we review the progress to date in high resolution imaging of cellular architecture. In particular we survey the progress in soft X-ray tomography and argue that the field is coming of age and that important biological insights are starting to emerge. We then review the new ideas based on coherent diffraction. These methods are at a much earlier stage of development but, as they eliminate the need for X-ray optics, have ...

  5. Large Area X-Ray Spectroscopy Mission

    Science.gov (United States)

    Tananbaum, H.

    1997-01-01

    The Large Area X-ray Spectroscopy (LAXS) mission concept study continues to evolve strongly following the merging of the LAXS mission with the Next Generation X-ray Observatory (NGXO, PI: Nick White) into the re-named High Throughput X-ray Spectroscopy (HTXS) Mission. HTXS retains key elements of the LAXS proposal, including the use of multiple satellites for risk-reduction and cost savings. A key achievement of the program has been the recommendation by the Structure and Evolution of the Universe (SEUS) (April 1997) for a new start for the HTXS mission in the 2000-2004 timeframe.

  6. The Future of X-Ray Optics

    Science.gov (United States)

    Weisskopf, Martin C.

    2013-01-01

    The most important next step is the development of X-ray optics comparable to (or better than) Chandra in angular resolution that far exceed Chandra s effective area. Use the long delay to establish an adequately funded, competitive technology program along the lines I have recommended. Don't be diverted from this objective, except for Explorer-class missions. Progress in X-ray optics, with emphasis on the angular resolution, is central to the paradigm-shifting discoveries and the contributions of X-ray astronomy to multiwavelength astrophysics over the past 51 years.

  7. X-ray emission from Centaurus A

    Energy Technology Data Exchange (ETDEWEB)

    Terrell, N.J.

    1981-01-01

    Observations of 3 to 12 keV x-ray emission from NGC 5128 (Cen A) were made by Vela spacecraft over the period 1969 to 1979. These data are in good agreement with previously reported data, but are much more complete. Numerous peaks of x-ray intensity occurred during the period 1973 to 1975, characterized by rapid increases and equally rapid decreases (in less than 10 days). Thus it seems probable that most of the x-ray flux from the nucleus of Cen A came from a single source of small size.

  8. X-rays from jets and lobes

    Science.gov (United States)

    Feigelson, E. D.

    1983-01-01

    The current status of X-ray detections (and non-detections) of radio jets and lobes is presented. High resolution images obtained with the Einstein Observatory reveal X-ray emission associated with jet and lobe components of Virgo A, Centaurus A, 3C273, and possibly other radio structures. The Vir A and Cen A jet emission is probably s ynchrotron in origin, requiring in situ particle acceleration to extremely high energies. Inverse Compton emission is the likely cause of asymmetrical X-ray features in the halo of Vir A, supporting the assumption of equipartition.

  9. X-rays from jets and lobes

    International Nuclear Information System (INIS)

    The current status of X-ray detections (and non-detections) of radio jets and lobes is reviewed. The author summarizes the findings and interpretation of several detections of jet and lobe X-ray emission made with the EINSTEIN observatory in Virgo A, Centaurus A, 3C273, and possibly other radio structures. The Vir A (=M27) and Cen A jet emission is probably synchrotron in origin, requiring in situ particle acceleration to extremely high energies. Inverse Compton emission is the likely cause of asymmetrical X-ray features in the halo of Vir A, supporting the assumption of equipartition. (Auth.)

  10. Nonlinear X-ray Compton Scattering

    OpenAIRE

    Fuchs, Matthias; Trigo, Mariano; Chen, Jian; Ghimire, Shambhu; Shwartz, Sharon; Kozina, Michael; Jiang, Mason; Henighan, Thomas; Bray, Crystal; Ndabashimiye, Georges; Bucksbaum, P. H.; Feng, Yiping; Herrmann, Sven; Carini, Gabriella; Pines, Jack

    2015-01-01

    X-ray scattering is a weak linear probe of matter. It is primarily sensitive to the position of electrons and their momentum distribution. Elastic X-ray scattering forms the basis of atomic structural determination while inelastic Compton scattering is often used as a spectroscopic probe of both single-particle excitations and collective modes. X-ray free-electron lasers (XFELs) are unique tools for studying matter on its natural time and length scales due to their bright and coherent ultrash...

  11. Advances in x-ray analysis

    International Nuclear Information System (INIS)

    This book presents papers given at the 1982 Denver Conference on the Applications of X-ray Analysis. Focus is on recent developments in measurement accuracy of two-theta and intensity. Topics include accuracy in x-ray powder diffraction (the theme of the conference); search/match procedures (Powder Diffraction File); quantitative XRD analysis; XRD application and automation; x-ray stress determination (position sensitive detectors, fatigue and fracture characterization); new XRF instrumentation and techniques; XRF computer systems and mathematical corrections; and XRF general applications

  12. Streaked, x-ray-transmission-grating spectrometer

    International Nuclear Information System (INIS)

    A free standing x-ray transmission grating has been coupled with a soft x-ray streak camera to produce a time resolved x-ray spectrometer. The instrument has a temporal resolution of approx. 20 psec, is capable of covering a broad spectral range, 2 to 120 A, has high sensitivity, and is simple to use requiring no complex alignment procedure. In recent laser fusion experiments the spectrometer successfully recorded time resolved spectra over the range 10 to 120 A with a spectral resolving power, lambda/Δlambda of 4 to 50, limited primarily by source size and collimation effects

  13. X-ray lenses with large aperture

    International Nuclear Information System (INIS)

    Up to now, most X-ray imaging setups are based on absorption contrast imaging. There is a demand for focused X-rays in many X-ray analysis applications, either to increase the resolution of an imaging system, or, to reduce the time effort of an experiment through higher photon flux. For photon energies higher than 15 keV refractive X-ray optics are more efficient in comparison to non-refractive X-ray optics. The aim of this work was to develop X-ray lenses with large apertures and high transparency. By increasing the number of refracting surfaces while removing unnecessary lens material such lenses have been developed. Utilizing this approach the overall beam deflection angle is large with respect to the lens material it propagates through and so the transparency of the lens is increased. Within this work, X-ray lenses consisting of several thousands of prisms with an edge length in the range of micrometers have been developed and fabricated by deep X-ray lithography. Deep X-ray lithography enables high precision microstrucures with smooth sidewalls and large aspect ratios. The aperture of high-transparency X-ray lenses made this way is greater than 1 mm. They are suitable for photon energies in the range of 8 keV to 24 keV and offer a focal width of smaller than 10 μm at a transparency of around 40%. Furthermore, rolled X-ray lenses have been developed, that are made out of a microstructured polyimide film, which is cut according to the requirements regarding focal length and photon energy. The microstructured film is fabricated by molding, using an anisotropically etched silicon wafer as molding tool. Its mean roughness is in the range of nanometers. The film features prismatic structures, its surface topology is similar to an asparagus field. The measured diameter of the point focus was 18 μm to 31 μm, the calculated opticla efficiency was 37%. Future work will concentrate on increasing the aspect ratio of Prism Lenses and on increasing the rolling accuracy

  14. Ten years of X-ray interferometry

    International Nuclear Information System (INIS)

    X-ray interferometers were the first optical instruments which utilized many Bragg reflecting components in monolithic blocks of perfect crystal. They have made important contributions to our knowledge of fundamental constants, of Bragg reflection x-ray optics, of strains and defects in crystals and of the optical constants of materials in the x-ray region of the electromagnetic spectrum. Based on an oversimplified optical analogue, their mode of operation is described in detail. Current applications of crystal interferometers and future work is briefly reviewed. (author)

  15. Fast X-Ray/IR cross-correlations and relativistic jet formation in GRS 1915+105

    CERN Document Server

    Lasso-Cabrera, Nestor M

    2013-01-01

    We present cross-correlation analyses of simultaneous X-ray and near-infrared (near-IR) observations of the microquasar GRS 1915+105 during relativistic jet-producing epochs (X-ray class $\\alpha$ and $\\beta$). While previous studies have linked the large-amplitude IR flares and X-ray behaviors to jet formation in these states, our new analyses are sensitive to much lower-amplitude IR variability, providing more sensitive probes of the jet formation process. The X-ray to IR cross-correlation function (CCF) shows significant correlations which vary in form between the different X-ray states. During low/hard dips in both classes, we find no significant X-ray/IR correlation. During high-variability epochs, we find consistently significant correlations in both $\\alpha$ and $\\beta$ classes, but with strong differences in the CCF structure. The high-variability $\\alpha$ CCF shows strong anti-correlation between X-ray/IR, with the X-ray preceding the IR by $\\sim$ 13 $\\pm$ 2s. The high-variability $\\beta$ state shows ...

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

    Directory of Open Access Journals (Sweden)

    L. Miaja-Avila

    2015-03-01

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

  17. X-ray diffraction contrast tomography (DCT) system, and an X-ray diffraction contrast tomography (DCT) method

    DEFF Research Database (Denmark)

    2012-01-01

    Source: US2012008736A An X-ray diffraction contrast tomography system (DCT) comprising a laboratory X-ray source (2), a staging device (5) rotating a polycrystalline material sample in the direct path of the X-ray beam, a first X-ray detector (6) detecting the direct X-ray beam being transmitted...

  18. Panoramic dental X-ray machine

    International Nuclear Information System (INIS)

    A panoramic dental X-ray machine is described possessing mechanical and electronic simplicity for providing both continuous and discontinuous radiographs of a dental arch area. The machine includes an excursion mechanism which causes a tubehead-camera assembly to uninterruptedly circularly orbit the patient's head at a constant speed. A drive mechanism is employed which controls the shifting or transport of the patient along an X-axis only, when either continuous or discontinuous images are desired. The kVp and milliamperes remain constant during the entire exposure of the patient to the X-rays as well as the rotational speed of the tubehead-camera assembly, and no attenuating members are required in the X-ray path for varying intensity of the X-ray beam. (Auth.)

  19. Future X-ray timing missions

    CERN Document Server

    Barret, D; Staubert, R; Stella, L

    2000-01-01

    Thanks to the Rossi X-ray Timing Explorer (RXTE), it is now widely recognized that fast X-ray timing can be used to probe strong gravity fields around collapsed objects and constrain the equation of state of dense matter in neutron stars. We first discuss some of the outstanding issues which could be solved with an X-ray timing mission building on the great successes of RXTE and providing an order of magnitude better sensitivity. Then we briefly describe the 'Experiment for X-ray timing and Relativistic Astrophysics' (EXTRA) recently proposed to the European Space Agency as a follow-up to RXTE and the related US mission 'Relativistic Astrophysics Explorer' (RAE).

  20. Future X-Ray Timing Missions

    Science.gov (United States)

    Barret, Didier; van der Klis, Michiel; Skinner, Gerry K.; Staubert, Rüdiger; Stella, Luigi

    Thanks to the Rossi X-ray Timing Explorer (RXTE), it is now widely recognized that fast X-ray timing can be used to probe strong gravity fields around collapsed objects and constrain the equation of state of dense matter in neutron stars. We first discuss some of the outstanding issues which could be solved with an X-ray timing mission building on the great successes of RXTE and providing an order of magnitude better sensitivity. Then we briefly describe the `Experiment for X-ray timing and Relativistic Astrophysics' (EXTRA) recently proposed to the European Space Agency as a follow-up to RXTE and the related US mission `Relativistic Astrophysics Explorer' (RAE).

  1. X-ray reprocessing in local AGN

    Science.gov (United States)

    Turner, J.

    2015-09-01

    Feature-rich X-ray spectra of local AGN reveal signatures from circumnuclear reprocessing gas spanning a wide range of column density and ionization state; this gas is likely dominant in shaping X-ray spectra and variability in AGN. Combining spectral information with X-ray time lag signatures indicates that the nuclear regions have a high covering fraction outflow of absorbing, Compton-scattering gas existing on scales of light- hours. We have applied a Monte Carlo Radiative Transfer model to the local AGN population and found the X-ray properties can be explained simply by changing the observer's sightline through a Compton-thick cloud ensemble, although other important cloud dependences, such as column denisty or ionization state are not ruled out.

  2. Nonrelativistic quantum X-ray physics

    CERN Document Server

    Hau-Riege, Stefan P

    2015-01-01

    Providing a solid theoretical background in photon-matter interaction, Nonrelativistic Quantum X-Ray Physics enables readers to understand experiments performed at XFEL-facilities and x-ray synchrotrons. As a result, after reading this book, scientists and students will be able to outline and perform calculations of some important x-ray-matter interaction processes. Key features of the contents are that the scope reaches beyond the dipole approximation when necessary and that it includes short-pulse interactions. To aid the reader in this transition, some relevant examples are discussed in detail, while non-relativistic quantum electrodynamics help readers to obtain an in-depth understanding of the formalisms and processes. The text presupposes a basic (undergraduate-level) understanding of mechanics, electrodynamics, and quantum mechanics. However, more specialized concepts in these fields are introduced and the reader is directed to appropriate references. While primarily benefiting users of x-ray light-sou...

  3. X-ray Emission from Solar Flares

    Indian Academy of Sciences (India)

    Rajmal Jain; Malini Aggarwal; Raghunandan Sharma

    2008-03-01

    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 particular. SOXS mission is composed of two solid state detectors, viz., Si and CZT semiconductors capable of observing the full disk Sun in X-ray energy range of 4–56 keV. The X-ray spectra of solar flares obtained by the Si detector in the 4–25 keV range show evidence of Fe and Fe/Ni line emission and multi-thermal plasma. The evolution of the break energy point that separates the thermal and non-thermal processes reveals increase with increasing flare plasma temperature. Small scale flare activities observed by both the detectors are found to be suitable to heat the active region corona; however their location appears to be in the transition region.

  4. (EXAFS) X-ray absorption spectroscopy

    International Nuclear Information System (INIS)

    The technique EXAFS (Extended X-Ray Absorption Fine Structure) is presented and its applications using the synchrotron radiation as an incidente beam in Science of Materials and Biophysics are shown. (L.C.)

  5. X-Ray Detector Simulations - Oral Presentation

    International Nuclear Information System (INIS)

    The free-electron laser at LCLS produces X-Rays that are used in several facilities. This light source is so bright and quick that we are capable of producing movies of objects like proteins. But making these movies would not be possible without a device that can detect the X-Rays and produce images. We need X-Ray cameras. The challenges LCLS faces include the X-Rays' high repetition rate of 120 Hz, short pulses that can reach 200 femto-seconds, and extreme peak brightness. We need detectors that are compatible with this light source, but before they can be used in the facilities, they must first be characterized. My project was to do just that, by making a computer simulation program. My presentation discusses the individual detectors I simulated, the details of my program, and how my project will help determine which detector is most useful for a specific experiment.

  6. Silicon Wafer X-ray Mirror Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this one year research project, we propose to do the following four tasks; (1) Design the silicon wafer X-ray mirror demo unit and develop a ray-tracing code to...

  7. Demonstration of X-ray talbot interferometry

    CERN Document Server

    Momose, A; Kawamoto, S; Hamaishi, Y; Takai, K; Suzuki, Y

    2003-01-01

    First Talbot interferometry in the hard X-ray region was demonstrated using a pair of transmission gratings made by forming gold stripes on glass plates. By aligning the gratings on the optical axis of X-rays with a separation that caused the Talbot effect by the first grating, moire fringes were produced inclining one grating slightly against the other around the optical axis. A phase object placed in front of the first grating was detected by moire-fringe bending. Using the technique of phase-shifting interferometry, the differential phase corresponding to the phase object could also be measured. This result suggests that X-ray Talbot interferometry is a novel and simple method for phase-sensitive X-ray radiography. (author)

  8. X-Ray Technologist Listing In California

    Data.gov (United States)

    U.S. Department of Health & Human Services — This table represents a current listing of X-Ray Technologists who are licensed by Radiologic Health Branch (RHB) of the California Department of Public Health. RHB...

  9. X-ray source for mammography

    Science.gov (United States)

    Logan, Clinton M.

    1994-01-01

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

  10. Dental x-ray diagnostic installation

    International Nuclear Information System (INIS)

    An exemplary embodiment comprises an exposure unit including an X-ray tube and a cassette holder rotatable about vertical axes and between which the head of the patient is disposed. A radiation detector is disposed at the cassette holder for supplying an electrical signal corresponding to the dose rate when it is struck by X-rays and being interconnected with an X-ray tube voltage controller and a dose rate regulator in such manner that the X-ray tube voltage is influenced by the output of the radiation detector to control the dose rate to a value producing an optimum film blackening. A function generator determining the speed of the exposure unit is provided in which a speed curve is stored given which the radiation dose influencing the film is approximately constant

  11. Chest X-Ray (Chest Radiography)

    Science.gov (United States)

    ... Lung tissue absorbs little radiation and will appear dark on the image. Until recently, x-ray images ... understanding of the possible charges you will incur. Web page review process: This Web page is reviewed ...

  12. Center for X-ray Optics (CXRO)

    Data.gov (United States)

    Federal Laboratory Consortium — The Center for X-Ray Optics at Lawrence Berkeley National Laboratory works to further science and technology using short wavelength optical systems and techniques....

  13. The Need for X-Ray Spectroscopy

    Science.gov (United States)

    Winebarger, Amy R.; Cirtain, Jonathan; Kobayashi, Ken

    2011-01-01

    For over four decades, X-ray, EUV, and UV spectral observations have been used to measure physical properties of the solar atmosphere. During this time, there has been substantial improvement in the spectral, spatial, and temporal resolution of the observations for the EUV and UV wavelength ranges. At wavelengths below 100 Angstroms, however, observations of the solar corona with simultaneous spatial and spectral resolution are limited, and not since the late 1970's have spatially resolved solar X-ray spectra been measured. The soft-X-ray wavelength range is dominated by emission lines formed at high temperatures and provides diagnostics unavailable in any other wavelength range. In this presentation, we will discuss the important science questions that can be answered using spatially and spectrally resolved X-ray spectra.

  14. Time-resolved suprathermal x-rays

    International Nuclear Information System (INIS)

    Temporally resolved x-ray spectra in the range of 1 to 20 keV have been obtained from gold disk targets irradiated by 1.06 μm laser pulses from the Argus facility. The x-ray streak camera used for the measurement has been calibrated for streak speed and dynamic range by using an air-gap Fabry-Perot etalon, and the instrument response has been calibrated using a multi-range monoenergetic x-ray source. The experimental results indicate that we are able to observe the ''hot'' x-ray temperature evolve in time and that the experimentally observed values can be qualitatively predicted by LASNEX code computations when the inhibited transport model is used

  15. X-ray imaging: Status and trends

    International Nuclear Information System (INIS)

    There is a veritable renaissance occurring in x-ray imaging. X-ray imaging by radiography has been a highly developed technology in medicine and industry for many years. However, high resolution imaging has not generally been practical because sources have been relatively dim and diffuse, optical elements have been nonexistent for most applications, and detectors have been slow and of low resolution. Materials analysis needs have therefore gone unmet. Rapid progress is now taking place because we are able to exploit developments in microelectronics and related material fabrication techniques, and because of the availability of intense x-ray sources. This report describes the methods and uses of x-ray imaging along with a discussion of technology advances in these areas

  16. X-ray microtomography in biology

    CERN Document Server

    Mizutani, Ryuta

    2016-01-01

    Progress in high-resolution x-ray microtomography has provided us with a practical approach to determining three-dimensional (3D) structures of opaque samples at micrometer to submicrometer resolution. In this review, we give an introduction to hard x-ray microtomography and its application to the visualization of 3D structures of biological soft tissues. Practical aspects of sample preparation, handling, data collection, 3D reconstruction, and structure analysis are described. Furthermore, different sample contrasting methods are approached in detail. Examples of microtomographic studies are overviewed to present an outline of biological applications of x-ray microtomography. We also provide perspectives of biological microtomography as the convergence of sciences in x-ray optics, biology, and structural analysis.

  17. Dentistry 4. X-ray diagnostics

    International Nuclear Information System (INIS)

    DIN pocketbook 267/4 gives an overview of the normative requirements of the new X-Ray and Radiation Protection Ordinance, which has been in effect since 1 November 2011. This DIN pocketbook is intended for anyone charged with professional responsibility for the use of ionizing radiation in dentistry, operators and users of x-ray devices, radiation protection officers, accredited experts, manufacturers as well as for anyone with an interest in radiation protection or optimal radiological diagnostics. It contains standards relating to the following areas: acceptance and constancy testing; devices for evaluating findings (monitors, film viewing devices), films, printers; archiving, designating, labelling. Adherence to the standards makes it possible to avoid distractive artefacts in x-ray images and optimise the quality of x-ray diagnostics in dentistry.

  18. Inelastic magnetic X-ray scattering

    Science.gov (United States)

    Platzman, P. M.; Tzoar, N.

    1985-04-01

    The theory of magnetic X-ray scattering is used to discuss the possibilities for employing inelastic scattering to probe the magnetic properties of condensed matter systems. In particular, it is shown how the interference between the nonmagnetic (Compton) and magnetic scattering arising from the use of circularly polarized X-rays is absolutely essential in such experiments. The very beautiful preliminary experiments by Sakai and Ono (1976) on Fe which use circularly polarized Moessbauer gamma-rays will be discussed. They already show the sensitivity of the technique to the 'magnetic form factor'. In addition, the physics of a unique quarter wave plate employed in obtaining circularly polarized X-rays is considered, and the implications of this advance for doing such experiments on existing synchrotron X-ray sources are discussed.

  19. 5.8 X-ray Calorimeters

    Science.gov (United States)

    Porter, F. Scott

    2008-01-01

    X-ray calorimeter instruments for astrophysics have seen rapid development since they were invented in 1984. The prime instrument on all currently planned X-ray spectroscopic observatories is based on calorimeter technology. This relatively simple detection concept that senses the energy of an incident photon by measuring the temperature rise of an absorber material at very low temperatures, can form the basis of a very high performance, non-dispersive spectrometer. State-of-the-art calorimeter instruments have resolving powers of over 3000, large simultaneous band-passes, and near unit efficiency. This coupled with the intrinsic imaging capability of a pixilated x-ray calorimeter array, allows true spectral-spatial instruments to be constructed. In this chapter I briefly review the detection scheme, the state-of-the-art in X-ray calorimeter instruments and the future outlook for this technology.

  20. Why Do I Need X-Rays?

    Science.gov (United States)

    ... information you need from the Academy of General Dentistry Wednesday, August 24, 2016 About | Contact InfoBites Quick ... Related Articles: X-Rays The Academy of General Dentistry (AGD) Sets the Record Straight on Dental X- ...

  1. Demonstration of X-ray talbot interferometry

    International Nuclear Information System (INIS)

    First Talbot interferometry in the hard X-ray region was demonstrated using a pair of transmission gratings made by forming gold stripes on glass plates. By aligning the gratings on the optical axis of X-rays with a separation that caused the Talbot effect by the first grating, moire fringes were produced inclining one grating slightly against the other around the optical axis. A phase object placed in front of the first grating was detected by moire-fringe bending. Using the technique of phase-shifting interferometry, the differential phase corresponding to the phase object could also be measured. This result suggests that X-ray Talbot interferometry is a novel and simple method for phase-sensitive X-ray radiography. (author)

  2. Silicon Wafer X-ray Mirror Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this one year research project, we propose to do the following four tasks;(1) Design the silicon wafer X-ray mirror demo unit and develop a ray-tracing code to...

  3. Experimental x-ray ghost imaging

    CERN Document Server

    Pelliccia, Daniele; Scheel, Mario; Cantelli, Valentina; Paganin, David M

    2016-01-01

    We report an experimental proof of principle for ghost imaging in the hard x-ray energy range. We used a synchrotron x-ray beam that was split using a thin crystal in Laue diffraction geometry. With an ultra-fast imaging camera, we were able to image x-rays generated by isolated electron bunches. At this time scale, the shot noise of the synchrotron emission process is measurable as speckles, leading to speckle correlation between the two beams. The integrated transmitted intensity from a sample located in the first beam was correlated with the spatially resolved intensity measured on the second, empty, beam to retrieve the shadow of the sample. The demonstration of ghost imaging with hard x-rays may open the way to protocols to reduce radiation damage in medical imaging and in non-destructive structural characterization using Free Electron Lasers.

  4. Tuberculosis, advanced - chest x-rays (image)

    Science.gov (United States)

    Tuberculosis is an infectious disease that causes inflammation, the formation of tubercules and other growths within tissue, ... death. These chest x-rays show advanced pulmonary tuberculosis. There are multiple light areas (opacities) of varying ...

  5. Linking Jet Emission, X-Ray States, and Hard X-Ray Tails in the Neutron Star X-Ray Binary GX 17+2

    NARCIS (Netherlands)

    S. Migliari; J.C.A. Miller-Jones; R.P. Fender; J. Homan; T. di Salvo; R.E. Rothschild; M.P. Rupen; J.A. Tomsick; R. Wijnands; M. van der Klis

    2007-01-01

    We present the results of simultaneous radio (VLA) and X-ray (RXTE) observations of the Z-type neutron star X-ray binary GX 17+2. The aim is to assess the coupling between X-ray and radio properties throughout its three rapidly variable X-ray states and during the time-resolved transitions. These ob

  6. Advanced detectors for X-ray microscopy

    International Nuclear Information System (INIS)

    Over the last decade the advances in x-ray microscopy have mainly been due to the development of x-ray source technology and to the micro-fabrication of x-ray optics. These advances have spurred the development of x-ray microscopes that are approaching the best resolution possible in the presence of radiation damage in the specimen. In addition, the development of specimen preparation techniques that reduce tile effects of radiation damage on the specimen are underway. In contrast, tile development or x-ray detectors for x-ray microscopy has been a low priority. The objective of the work was to develop a new detector for x-ray microscopy. This involved the modification of a Thorn EMI electron tube in order to sensitise the multiplier for soil x-rays In the energy range of interest (0.2-6 keV). The electron multiplier was then tested on a repetitive laser plasma source, which has been shown to be eminently suitable for a laboratory scale x-ray microscope, and the Scanning Transmission X-ray Microscope (STXM) at the National Synchrotron Light Source (NSLS), which is the most successful STXM presently in operation. The processed data from tile electron multiplier was used to characterise its response and assess its potential as all alternative to existing detectors. In addition, ID21, the microscopy beamline at the European Synchrotron Radiation Source (ESRF) was studied to assess the need for a beam position monitor close to the exit slit of the monochromator. This involved the ray tracing of the beamline. It was proposed that in the case of a crystal monochromator a beam position monitor based oil the total signal from a photo-emitting blade containing a number of different diameter pinholes was sufficient. However, for a grating monochromator tile beamline design relied upon feedback from a beam position monitor capable of detecting the height of the beam at tile entrance to the microscope. A number of conceptual designs for a monitor that could fulfil this

  7. Principles of X-ray Navigation

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, John Eric; /SLAC

    2006-03-17

    X-ray navigation is a new concept in satellite navigation in which orientation, position and time are measured by observing stellar emissions in x-ray wavelengths. X-ray navigation offers the opportunity for a single instrument to be used to measure these parameters autonomously. Furthermore, this concept is not limited to missions in close proximity to the earth. X-ray navigation can be used on a variety of missions from satellites in low earth orbit to spacecraft on interplanetary missions. In 1997 the Unconventional Stellar Aspect Experiment (USA) will be launched as part of the Advanced Research and Global Observation Satellite (ARGOS). USA will provide the first platform for real-time experimentation in the field of x-ray navigation and also serves as an excellent case study for the design and manufacturing of space qualified systems in small, autonomous groups. Current techniques for determining the orientation of a satellite rely on observations of the earth, sun and stars in infrared, visible or ultraviolet wavelengths. It is possible to use x-ray imaging devices to provide arcsecond level measurement of attitude based on star patterns in the x-ray sky. This technique is explored with a simple simulation. Collimated x-ray detectors can be used on spinning satellites to provide a cheap and reliable measure of orientation. This is demonstrated using observations of the Crab Pulsar taken by the high Energy Astronomy Observatory (HEAO-1) in 1977. A single instrument concept is shown to be effective, but dependent on an a priori estimate of the guide star intensity and thus susceptible to errors in that estimate. A star scanner based on a differential measurement from two x-ray detectors eliminates the need for an a priori estimate of the guide star intensity. A first order model and a second order model of the two star scanner concepts are considered. Many of the stars that emit in the x-ray regime are also x-ray pulsars with frequency stability approaching a

  8. \\gamma Cassiopeiae: an X-ray Be star with personality

    CERN Document Server

    de Oliveira, Raimundo Lopes; Motch, Christian; ;,

    2009-01-01

    \\gamma Cas is a B0.5e star with peculiar X-ray emission properties and yet the prototype of its own small class. In this paper we examine the X-ray spectra for a 2004 XMM-Newton observation and a previously published 2001 Chandra observation. In both cases the spectra can be modeled with 3 or 4 thermal components, which appear be discrete in temperature and spatially distinct. The dominant component, having kT ~ 12 keV contributes most of the flux. The secondary components have temperatures in the range of 2-3 keV to 0.1 keV; these values can shift in time. Importantly, we find that the strong absorption of soft X-rays in 2001 is absent in 2004, meaning that an absorbing column in front of the source has moved off the star or has been removed. Other differences include a reduced Fe abundance from the ionized lines of the FeKalpha complex (even more subsolar than the 2001 observation), an increase in the Fe K fluoresence feature, and from the NVII and NeX H-alpha lines, a possible overabundance of N and Ne. Al...

  9. Probing the Galactic center with X-ray polarimetry

    CERN Document Server

    Marin, F; Kunneriath, D; Muleri, F; Soffitta, P

    2014-01-01

    The Galactic center (GC) holds the closest-to-Earth supermassive black hole (SMBH), which makes it the best laboratory to study the close environment of extremely massive compact objects. Polarimetry is sensitive to geometry of the source, which makes it a particularly suitable technique to probe the medium surrounding the GC SMBH. The detection of hard X-ray spectra and prominent iron K$\\alpha$ fluorescence features coincident with localized gas clouds (e.g. Sgr~B2, Sgr~C) is known for nearly twenty years now and is commonly associated with a past outburst of the SMBH whose radiation is reprocessing onto the so-called "reflection nebulae". Since scattering leads to polarization, the re-emitted signal from the giant molecular clouds in the first 100~pc of the GC is expected to be polarized. X-ray polarization measurement is thus particularly adapted to probe the origin of the diffuse X-ray emission from the GC reflection nebulae and reveal the past activity of the central SMBH. In this research note, we summa...

  10. Development of a fast X-ray detector

    International Nuclear Information System (INIS)

    A gas scintillation drift counter has been developed. This counter, which is capable of working in a digital mode at a quite high rate without producing space charge effects has been modified as a high counting rate X-ray detector. Scintillation and transport properties of an argon/nitrogen gas mixture have been studied using an Am241 alpha-particle source and an Fe55 5.9 keV radioactive X-ray source in order to obtain relative compositions of argon and nitrogen. The effects of various operating parameters on the energy resolution of the counter and the characteristics of output pulses have been extensively studied. Pulse responses, gain variations with counting rate and stability of the photomultiplier used to detect scintillation light have been investigated using a light emitting diode pulsar, a constant light source and primary scintillation pulses from 6.9 keV X-rays. The dynode potentials have been stabilised using emitter follower configurations. Energy and time resolution performances are given. A counting rate of 9.5 MHz is possible at the expense of energy resolution. (U.K.)

  11. Capacitor discharges, magnetohydrodynamics, X-rays, ultrasonics

    CERN Document Server

    Früngel, Frank B A

    1965-01-01

    High Speed Pulse Technology, Volume 1: Capacitor Discharges - Magnetohydrodynamics - X-Rays - Ultrasonics deals with the theoretical and engineering problems that arise in the capacitor discharge technique.This book discusses the characteristics of dielectric material, symmetrical switch tubes with mercury filling, and compensation conductor forms. The transformed discharge for highest current peaks, ignition transformer for internal combustion engines, and X-ray irradiation of subjects in mechanical motion are also elaborated. This text likewise covers the transformed capacitor discharge in w

  12. X-ray observations of stellar coronae

    International Nuclear Information System (INIS)

    The Einstein X-Ray Observatory (HEAO-2) has been used to search for X-ray emission from a wide variety of stars in our galaxy. A significant fraction of the data was obtained via the 8.5 magnitude stellar survey, which is reported here. This survey searches for X-ray emission from all stars brighter than visual magnitude 8.5 that serendipitously fell into the Imaging Proportional Counter field-of-view of the Einstein Observatory. The survey includes 227 separate fields that contain a total of 276 stars with V < 8.5. A wide range of spectral types and luminosity classes are represented. X-Ray emission in excess of 3-sigma above local background was discovered from 33 stars; 3-sigma upper limits have been determined for the remaining 243 stars. Comparison of X-ray source detection statistics with the expected frequency of stars brighter than V = 8.5 as a function of spectral type and luminosity class shows that the present visual magnitude limited survey can define the X-ray luminosity for dwarf F stars and provides constraints for the high luminosity tails of the X-ray luminosity functions for other types of stars constructed from other Einstein observations. The results of the 8.5 and Gliese survey have been integrated with those of four othe Einstein surveys. In total, X-ray emission has been detected from 156 stars, with most of these representing initial discoveries. Most of the observations can be explained by the presence of hot coronae around stars of nearly every spectral type. The consequences of these observations in terms of the presence of stellar outer convection zones, surface magnetic fields, and rotation rates are discussed

  13. Supernova remnants: the X-ray perspective

    OpenAIRE

    Vink, Jacco

    2011-01-01

    Supernova remnants are beautiful astronomical objects that are also of high scientific interest, because they provide insights into supernova explosion mechanisms, and because they are the likely sources of Galactic cosmic rays. X-ray observations are an important means to study these objects.And in particular the advances made in X-ray imaging spectroscopy over the last two decades has greatly increased our knowledge about supernova remnants. It has made it possible to map the products of fr...

  14. Scattered X-ray beam nondestructive testing

    Science.gov (United States)

    Harding, G.; Kosanetzky, J.

    1989-08-01

    X-ray scatter interactions generally dominate the linear attenuation coefficient at the photon energies typical of medical and industrial radiography. Specific advantages of X-ray scatter imaging, including a flexible choice of measurement geometry, direct 3D-imaging capability (tomography) and improved information for material characterization, are illustrated with results from Compton and coherent scatter devices. Applications of a Compton backscatter scanner (ComScan) in the aerospace industry and coherent scatter imaging in security screening are briefly considered.

  15. High speed gated x-ray imagers

    International Nuclear Information System (INIS)

    Single and multi-frame gated x-ray images with time-resolution as fast as 150 psec are described. These systems are based on the gating of microchannel plates in a stripline configuration. The gating voltage comes from the avalanche breakdown of reverse biased p-n junction producing high power voltage pulses as short as 70 psec. Results from single and four frame x-ray cameras used on Nova are described. 8 refs., 9 figs

  16. Multi-layer X-ray screens

    International Nuclear Information System (INIS)

    Rare earth (La or Gd) oxyhalide phosphors activated with thulium ion are employed in x-ray intensifying screens having modified ultraviolet emission characteristics which reduce crossover effects without significant reduction in brightness or film speed. Relatively low concentration levels of the thulium activator ion have been found to shift the ultraviolet emission of said phosphor when excited by x-rays to lower wavelengths in both the ultraviolet and near-ultraviolet spectral regions. (author)

  17. X-ray laser program at MBI

    Science.gov (United States)

    Nickles, P. V.; Janulewicz, K. A.; Lucianetti, A.; Priebe, G.; Zigler, A.; Rocca, J. J.; Sandner, W.

    2002-11-01

    A survey of the Max Born Institute (MBI) activities in the field of X-ray lasers (XRLs) is presented. The main interest is focused on the transient soft X-ray lasers. Additionally, much work is put to look for new, efficient, compact (table-top) pumping schemes with a prospect to be applied in practice. The current state of the research and the plans for the future are described as well.

  18. Refractive lens for hard x-rays

    International Nuclear Information System (INIS)

    The refractive lens for hard X-rays on the base of glass capillary is presented. The fabrication techniques for lens production are described. The model of refractive lens for hard X-ray is proposed. The model assume that the compound lens work similar one thin lens the complex refraction index of which is following: n=1-δ N + i β N. On the base of this model the parameters of focussed beam are calculated and the images of object are constructed

  19. Parametric X-rays at FAST

    Energy Technology Data Exchange (ETDEWEB)

    Sen, Tanaji [Fermilab

    2016-06-01

    We discuss the generation of parametric X-rays (PXR) in the photoinjector at the new FAST facility at Fermilab. Detailed calculations of the intensity spectrum, energy and angular widths and spectral brilliance with a diamond crystal are presented. We also report on expected results with PXR generated while the beam is channeling. The low emittance electron beam makes this facility a promising source for creating brilliant X-rays.

  20. AXIOM: Advanced X-ray Imaging of the Magnetosphere

    Science.gov (United States)

    Branduardi-Raymont, G.; Sembay, S. F.; Eastwood, J. P.; Sibeck, D. G.; Abbey, A.; Brown, P.; Carter, J. A.; Carr, C. M.; Forsyth, C.; Kataria, D.; Kemble, S.; Milan, S. E.; Owen, C. J.; Peacocke, L.; Read, A. M.; Coates, A. J.; Collier, M. R.; Cowley, S. W. H.; Fazakerley, A. N.; Fraser, G. W.; Jones, G. H.; Lallement, R.; Lester, M.; Porter, F. S.; Yeoman, T. K.

    2012-01-01

    Planetary plasma and magnetic field environments can be studied in two complementary ways - by in situ measurements, or by remote sensing. While the former provide precise information about plasma behaviour, instabilities and dynamics on local scales, the latter offers the global view necessary to understand the overall interaction of the magnetospheric plasma with the solar wind. Some parts of the Earth's magnetosphere have been remotely sensed, but the majority remains unexplored by this type of measurements. Here we propose a novel and more elegant approach employing remote X-ray imaging techniques. which are now possible thanks to the relatively recent discovery of solar wind charge exchange X-ray emissions in the vicinity of the Earth's magnetosphere. In this article we describe how an appropriately designed and located. X-ray telescope, supported by simultaneous in situ measurements of the solar wind, can be used to image the dayside magnetosphere, magnetosheath and bow shock. with a temporal and spatial resolution sufficient to address several key outstanding questions concerning how the solar wind interacts with the Earth's magnetosphere on a global level. Global images of the dayside magnetospheric boundaries require vantage points well outside the magnetosphere. Our studies have led us to propose 'AXIOM: Advanced X-ray Imaging Of the Magnetosphere', a concept mission using a Vega launcher with a LISA Pathfinder-type Propulsion Module to place the spacecraft in a Lissajous orbit around the Earth - Moon Ll point. The model payload consists of an X-ray Wide Field Imager, capable of both imaging and spectroscopy, and an in situ plasma and magnetic field measurement package. This package comprises a Proton-Alpha Sensor, designed to measure the bulk properties of the solar wind, an Ion Composition Analyser, to characterize the minor ion populations in the solar wind that cause charge exchange emission, and a Magnetometer, designed to measure the strength and

  1. Detection limits in x-ray fluorescence analysis

    International Nuclear Information System (INIS)

    X-ray fluorescence spectrometry is a well established analytical technique for elemental analysis of solids, powders, or liquids. This extended abstract briefly discusses the detection limits or sensitivity of x-ray spectrometers in x-ray fluorescence analysis

  2. The ROSAT X-ray Background Dipole

    CERN Document Server

    Plionis, M

    1998-01-01

    We estimate the dipole of the diffuse 1.5 keV X-ray background from the ROSAT all-sky survey map of Snowden et al (1995). We first subtract the diffuse Galactic emission by fitting to the data an exponential scale height, finite radius, disk model. We further exclude regions of low galactic latitudes, of local X-ray emission (eg the North Polar Spur) and model them using two different methods. We find that the ROSAT X-ray background (XRB) dipole points towards $(l,b) ~ (288, 25) \\pm 19 degrees within 30 degrees of the CMB dipole. Its direction is also in good agreement with the HEAO1 X-ray dipole at harder energies. The normalised amplitude of the ROSAT XRB dipole is about 1.7 per cent. Subtracting from the ROSAT map the expected X-ray background dipole due to the reflex motion of the observer with respect to the cosmic rest frame (Compton-Geting effect) we find the large-scale dipole of the X-ray emitting extragalactic sources having an amplitude 90% of the total XRB, in general agreement with the prediction...

  3. Portable fluid X-ray diagnostic system

    International Nuclear Information System (INIS)

    A portable X-ray image system is described comprising: (a) a base assembly including panels and hinges joining the panels together along edges, and compression stops for biasing the hinges to compensate for the weight of payload when mounted on the base assembly, the compression stops being located for interaction with the hinges for biasing the panels to exhibit upward bowing when laid upon a flat surface prior to loading, and to provide resiliency for facilitating the base assembly assuming a substantially flat configuration when a predetermined payload is placed upon the base assembly; (b) an X-ray member; (c) apparatus for detachably mounting a table member to the base assembly to hold the table member at a location above the base; (d) an X-ray source; (e) means for sensing X-rays to form an image; (f) means for mounting the X-ray source and the X-ray sensing means on opposite sides relative to the table member and supported by the base assembly; (g) releasable clamping apparatus associated with the hinges for rendering the joints of the base assembly substantially rigid; (h) means for adjustably leveling the base assembly, and (i) means for indicating the attitude of the base assembly with respect to the horizontal

  4. X-ray Emission of Hollow Atoms

    Institute of Scientific and Technical Information of China (English)

    ZhaoYongtao; XiaoGuoqing; ZhangXiaoan; YangZhihu; ChenXimeng; ZhangYanping

    2003-01-01

    We have systematically investigated the X-rays emission of hollow atoms (HA) which formed in the interaction of highly charged ions with a variety of solid surfaces at the atomic physics experimental setup of IMP. The X-ray spectra were measured by Si(Li) detectors with effective energy ranging from 1 keV to 60 keV. The results show that, the X-ray emission from the formed HA is closely correlated with the charge state of the projectile ions, and weakly correlated with the velocity of the projectile ions. For example, it was found that when Ar18+ ions interact with Be-target, the yield of K X-ray with character energy of 3.0 keV is 7.2×10-3 per ion, which is two times and 5 order of magnitude higher than those in the interactions of Ar17+ and Ar16+ ions respectively. When Ar15+ ions interact with the same targets, the Argon K X-ray would be too feeble to be detected. The X-ray yield with single ion in this experiment can be represented by the following equation,

  5. X-ray refraction-contrast imaging

    International Nuclear Information System (INIS)

    The conventional x-ray imaging for soft tissue often produced some adverse effects because of contrast medium and high-dose radiation. This report outlines the recently developed a very sensitive x-ray imaging method called as refraction contrast method or x-ray Schlieren method, which allows to detect density difference and irregularity in the soft tissue. In the apparatus (SPring-8 BL47XU), a light emitted from undulator was monochromatized by two-crystal x-ray spectroscope and x-ray passed through a sample was caught by imaging detector equipped with a combination of relay lens and CCD. When a glass capillary (outer diameter: 660 μm, inner diameter: 220 μm) was used as a measuring sample, it was confirmed that the image through geometrical refraction was obtained. When x-ray images of a dragonfly wing obtained by the Schlieren method (sample-detector distance: 5 m) and the conventional contact method were compared, it was demonstrated that reticulate structure of the wing was clearly observed by the former method but not at all by the latter one. At present, the study on efficacy of the refraction contrast imaging is under way using rodents. (M.N.)

  6. Years of Magnetic X-Ray Dichroism

    Science.gov (United States)

    van der Laan, Gerrit

    A historical overview of magnetic x-ray dichroism is presented. I describe the first theoretical and experimental results that have led to the development of this powerful technique for element-specific magnetometry. The theoretical progress of the sum rules is also described, starting with the spinorbit sum rule for the isotropic spectrum which led on to the spin and orbital moment sum rules for x-ray magnetic circular dichroism. The latter has been particularly useful to understand the magnetic anisotropy in thin films and multilayers. Further developments of circular dichroism in (resonant) photoemission and Auger, as well as x-ray detected optical activity, also are summarized. Currently, magnetic x-ray dichroism finds a wide application in x-ray spectroscopy and imaging for the study of magnetic materials and it is considered to be one of the most important discoveries in the field of magnetism in the last few decennia. It is hard to imagine modern research into magnetism without the aid of polarized x-rays.

  7. Technological challenges to X-ray FELs

    CERN Document Server

    Nuhn, H D

    2000-01-01

    There is strong interest in the development of X-ray Free Electron Lasers (X-ray FELs). The interest is driven by the scientific opportunities provided by intense, coherent X-rays. An X-ray FEL has all the characteristics of a fourth-generation source: brightness several orders of magnitude greater than presently achieved in third-generation sources, full transverse coherence, and sub-picosecond long pulses. The SLAC and DESY laboratories have presented detailed design studies for X-ray FEL user-facilities around the 0.1 nm wavelength regime (LCLS at SLAC, TESLA X-ray FEL at DESY). Both laboratories are engaged in proof-of-principle experiments at longer wavelengths (TTF FEL Phase I at 71 nm, VISA at 600-800 nm) with results expected in 1999. The technologies needed to achieve the proposed performances are those of bright electron sources, of acceleration systems capable of preserving the brightness of the source, and of undulators capable of meeting the magnetic and mechanical tolerances that are required fo...

  8. X-ray nanotomography in a SEM

    Science.gov (United States)

    Pauwels, Bart; Liu, Xuan; Sasov, Alexander

    2010-09-01

    We have developed an x-ray computer tomography (CT) add-on to perform X-ray micro- and nanotomography in any scanning electron microscope (SEM). The electron beam inside the SEM is focused on a metal target to generate x-rays. Part of the X-rays pass through the object that is installed on a rotation stage. Shadow X-ray images are collected by a CCD camera with direct photon detection mounted on the external wall of the SEM specimen chamber. An extensive description on the working principles of this micro/nano-CT add-on together with some examples of CT-scans will be given in this paper. The resolution that can be obtained with this set-up and the influence of the shape of the electron beam are discussed. Furthermore, possible improvements on this SEM-CT set-up will be discussed: replacing the backilluminated CCD with a fully depleted CCD with improved quantum efficiency (QE) for higher energies, reduces the exposure time by 6 when using metal targets with x-ray characteristic lines around 10 keV.

  9. A million X-ray detections

    Science.gov (United States)

    Webb, N.; XMM-Newton Survey Science Centre (SSC)

    2016-06-01

    Part of the XMM-Newton Survey Science Centre responsibilities include producing an X-ray catalogue of all X-ray sources detected with XMM-Newton. The latest version, 3XMM, takes advantage of improvements made to the source characterisation, reducing the number of spurious detections, but providing better astrometric precision, greater net sensitivity, as well as spectra and timeseries for a quarter of all catalogue detections. The data release 5 (3XMM-DR5, April 2015) is derived from the first 13 years of observations with XMM-Newton. 3XMM-DR5 includes 565962 X-ray detections and 396910 unique sources, detected as many as 48 times. 3XMM-DR5 is therefore the largest X-ray source catalogue. 3XMM-DR6 will be made available during 2016 and will augment the catalogue with 70000 X-ray detections. Over the next decade the catalogue will reach 1 million X-ray detections, including galaxy clusters, galaxies, tidal disruption events, gamma-ray bursts, stars, stellar mass compact objects, supernovae, planets, comets and many other systems. Thanks to the wide range of data products for each catalogue detection, the catalogue is an excellent resource for finding populations of sources as well as new and extreme objects. Here we present results achieved from searching the catalogue and discuss improvements that will be provided in future versions.

  10. The SAS-3 X-ray observatory

    Science.gov (United States)

    Mayer, W. F.

    1975-01-01

    The experiment section of the Small Astronomy Satellite-3 (SAS-3) launched in May 1975 is an X-ray observatory intended to determine the location of bright X-ray sources to an accuracy of 15 arc-seconds; to study a selected set of sources over a wide energy range, from 0.1 to 55 keV, while performing very specific measurements of the spectra and time variability of known X-ray sources; and to monitor the sky continuously for X-ray novae, flares, and unexpected phenomena. The improvements in SAS-3 spacecraft include a clock accurate to 1 part in 10 billion, rotatable solar panels, a programmable data format, and improved nutation damper, a delayed command system, improved magnetic trim and azimuth control systems. These improvements enable SAS-3 to perform three-axis stabilized observations of any point on the celestial sphere at any time of the year. The description of the experiment section and the SAS-3 operation is followed by a synopsis of scientific results obtained from the observations of X-ray sources, such as Vela X-1 (supposed to be an accreting neutron star), a transient source of hard X-ray (less than 36 min in duration) detected by SAS-3, the Crab Nebula pulsar, the Perseus cluster of galaxies, and the Vela supernova remnant.

  11. Optics Developments for X-Ray Astronomy

    Science.gov (United States)

    Ramsey, Brian

    2014-01-01

    X-ray optics has revolutionized x-ray astronomy. The degree of background suppression that these afford, have led to a tremendous increase in sensitivity. The current Chandra observatory has the same collecting area (approx. 10(exp 3)sq cm) as the non-imaging UHURU observatory, the first x-ray observatory which launched in 1970, but has 5 orders of magnitude more sensitivity due to its focusing optics. In addition, its 0.5 arcsec angular resolution has revealed a wealth of structure in many cosmic x-ray sources. The Chandra observatory achieved its resolution by using relatively thick pieces of Zerodur glass, which were meticulously figured and polished to form the four-shell nested array. The resulting optical assembly weighed around 1600 kg, and cost approximately $0.5B. The challenge for future x-ray astronomy missions is to greatly increase the collecting area (by one or more orders of magnitude) while maintaining high angular resolution, and all within realistic mass and budget constraints. A review of the current status of US optics for x-ray astronomy will be provided along with the challenges for future developments.

  12. The Constellation X-ray mission

    International Nuclear Information System (INIS)

    The Constellation-X mission is a large collecting area X-ray facility, emphasizing observations at high spectral resolution (E/ΔE∼300-3000) while covering a broad energy band (0.25-40 keV). By increasing the telescope aperture and utilizing efficient spectrometers the mission will achieve a factor of 100 increased sensitivity over current high-resolution X-ray spectroscopy missions. The use of focussing optics across the 10-40 keV band will provide a similar factor of 100 increased sensitivity in this band. Key technologies under development for the mission include lightweight high throughput X-ray optics, multilayer coatings to enhance the hard X-ray performance of X-ray optics, micro-calorimeter spectrometer arrays with 2 eV resolution, low-power and low-weight CCD arrays, lightweight gratings and hard X-ray detectors. When observations commence towards the end of the next decade, Constellation-X will address many pressing questions concerning the extremes of gravity and the evolution of the Universe

  13. Low exposure x-ray transmission measurements for contrast media detection with filtered x-rays

    International Nuclear Information System (INIS)

    A feasibility study of X-ray transmission measurements for contrast media with less exposure using filtered X-rays and their energy information is described. Based on measurements of the energy spectra of La-filtered X-rays, sensitivity to the contrast media and the relative quantity of dose exposure of filtered X-rays as the ratio to white X-rays are shown. The dose exposure for the measurement of iodine contrast media is reduced by more than 50% with a 400 μm thick La filter. By using a filter with atomic number close to that of iodine such as Cs and Ba, a greater reduction in dose exposure with a smaller increase in the current of the X-ray tube is expected. (author)

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

    Science.gov (United States)

    Hoshino, Masato; Uesugi, Kentaro; Takeuchi, Akihisa; Suzuki, Yoshio; Yagi, Naoto

    2011-07-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-07-15

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

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

    International Nuclear Information System (INIS)

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

  17. Effects of x-ray does on rhizosphere studies using x-ray computed tomography

    OpenAIRE

    Susan Zappala; Jonathan R Helliwell; Tracy, Saoirse R.; Stefan Mairhofer; Sturrock, Craig J.; Tony Pridmore; Malcolm Bennett; Sacha J. Mooney

    2013-01-01

    X-ray Computed Tomography (CT) is a non-destructive imaging technique originally designed for diagnostic medicine, which was adopted for rhizosphere and soil science applications in the early 1980s. X-ray CT enables researchers to simultaneously visualise and quantify the heterogeneous soil matrix of mineral grains, organic matter, air-filled pores and water-filled pores. Additionally, X-ray CT allows visualisation of plant roots in situ without the need for traditional invasive methods such ...

  18. Simulation of transmitted X-rays in a polycapillary X-ray lens

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Shiqi [The Key Laboratory of Beam Technology and Material Modification of the Ministry of Education, Beijing Normal University, Beijing 100875 (China); College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); Liu, Zhiguo, E-mail: liuzhiguo512@126.com [The Key Laboratory of Beam Technology and Material Modification of the Ministry of Education, Beijing Normal University, Beijing 100875 (China); College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); Sun, Tianxi; Wang, Kai; Yi, Longtao; Yang, Kui; Chen, Man; Wang, Jinbang [The Key Laboratory of Beam Technology and Material Modification of the Ministry of Education, Beijing Normal University, Beijing 100875 (China); College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China)

    2015-09-21

    The geometrical description of capillary systems adjusted for the controlled guiding of X-rays and the basic theory of the transmission of X-rays are presented. A method of numerical calculation, based on Ray-Tracing theory, is developed to simulate the transmission efficiency of an X-ray parallel lens and the shape and size of the light spot gain from it. The simulation results for two half-lenses are in good agreement with the experimental results.

  19. Simulation of transmitted X-rays in a polycapillary X-ray lens

    International Nuclear Information System (INIS)

    The geometrical description of capillary systems adjusted for the controlled guiding of X-rays and the basic theory of the transmission of X-rays are presented. A method of numerical calculation, based on Ray-Tracing theory, is developed to simulate the transmission efficiency of an X-ray parallel lens and the shape and size of the light spot gain from it. The simulation results for two half-lenses are in good agreement with the experimental results

  20. The first Swift X-ray Flash: The faint afterglow of XRF 050215B

    CERN Document Server

    Levan, A J; Tanvir, N R; Page, K L; Rol, E; Zhang, B; Goad, M R; O'Brien, P T; Priddey, R S; Bersier, D; Burrows, D N; Chapman, R; Fruchter, A S; Giommi, P; Gehrels, N; Hughes, M A; Pak, S; Simpson, C; Tagliaferri, G; Vardoulaki, E

    2006-01-01

    We present the discovery of XRF 050215B and its afterglow. The burst was detected by the Swift BAT during the check-out phase and observations with the X-ray telescope began approximately 30 minutes after the burst. These observations found a faint, slowly fading X-ray afterglow near the centre of the error box as reported by the BAT. Infrared data, obtained at UKIRT after 10 hours also revealed a very faint K-band afterglow. The afterglow appear unusual since it is very faint, especially in the infrared with K>20 only 9 hours post burst. The X-ray and infrared lightcurves exhibit a slow, monotonic decay with alpha=0.8 and no evidence for steepening associated with the jet break to 10 days post burst. We discuss possible explanations for the faintness and slow decay in the context of present models for the production of X-ray Flashes.

  1. High-resolution x-ray studies of an AXAF high-energy transmission grating

    DEFF Research Database (Denmark)

    Abdali, S.; Christensen, Finn Erland; Schnopper, H. W.;

    1993-01-01

    A triple axis X-ray diffractometer, designed and built at the Danish Space Research Institute, was used to make a high resolution study of the performance of a 2000 angstroms period, high energy X-ray transmission grating developed at MIT for one of the grating spectrometers on the Advanced X......-ray Astrophysics Facility. Data was obtained at CuK(alpha )1 (8.048 keV) and, using single reflection asymmetric Si(044) crystals for both the monochromator and analyzer, an angular resolution of 1.5 arcsec FWHM was achieved. The efficiency of the grating in all orders up to the 15th was measured using a 12 k......W rotating anode X-ray generator. These data provided the basis for a modelling of the grating structure....

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

    Science.gov (United States)

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

    2016-08-01

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

  3. Comparison of x-ray output of inverter-type x-ray equipment

    International Nuclear Information System (INIS)

    The x-ray output of 54 inverter-type x-ray apparatuses used at 18 institutions was investigated. The reproducibility and linearity of x-ray output and variations among the x-ray equipment were evaluated using the same fluorescence meter. In addition, the x-ray apparatuses were re-measured using the same non-invasive instrument to check for variations in tube voltage, tube current, and irradiation time. The non-invasive instrument was calibrated by simultaneously obtaining measurements with an invasive instrument, employing the tube voltage and current used for the invasive instrument, and the difference was calculated. Reproducibility of x-ray output was satisfactory for all x-ray apparatuses. The coefficient of variation was 0.04 or less for irradiation times of 5 ms or longer. In 84.3% of all x-ray equipment, variation in the linearity of x-ray output was 15% or less for an irradiation time of 5 ms. However, for all the apparatuses, the figure was 50% when irradiation time was the shortest (1 to 3 ms). Variation in x-ray output increased as irradiation time decreased. Variation in x-ray output ranged between 1.8 and 2.5 compared with the maximum and minimum values, excluding those obtained at the shortest irradiation time. The relative standard deviation ranged from ±15.5% to ±21.0%. The largest variation in x-ray output was confirmed in regions irradiated for the shortest time, with smaller variations observed for longer irradiation times. The major factor responsible for variation in x-ray output in regions irradiated for 10 ms or longer, which is a relatively long irradiation time, was variation in tube current. Variation in tube current was slightly greater than 30% at maximum, with an average value of 7% compared with the preset tube current. Variations in x-ray output in regions irradiated for the shortest time were due to photographic effects related to the rise and fall times of the tube voltage waveform. Accordingly, in order to obtain constant x-ray

  4. Fabrication of large area X-ray diffraction grating for X-ray phase imaging

    International Nuclear Information System (INIS)

    X-ray lithography, which uses highly directional synchrotron radiation, is one of the technologies that can be used for fabricating micrometer-sized structures. In X-ray lithography, the accuracy of the fabricated structure depends largely on the accuracy of the X-ray mask. Since X-ray radiation is highly directional, a micro-fabrication technology that produces un-tapered and high aspect ratio highly absorbent structures on a low absorbent membrane is required. Conventionally, a resin material is used as the support membrane for large area X-ray masks. However, resin membranes have the disadvantage that they can sag after several cycles of X-ray exposure due to the heat generated by the X-rays. Therefore, we proposed and used thin carbon wafers for the membrane material because carbon has an extremely small thermal expansion coefficient. We fabricated new carbon membrane X-ray masks, and these results of X-ray lithography demonstrate the superior performance.

  5. X-ray-induced photo-chemistry and X-ray absorption spectroscopy of biological samples

    OpenAIRE

    George, Graham N.; Pickering, Ingrid J.; Pushie, M. Jake; Nienaber, Kurt; Hackett, Mark J.; Ascone, Isabella; Hedman, Britt; Hodgson, Keith O.; Aitken, Jade B.; Levina, Aviva; Glover, Christopher; Lay, Peter A.

    2012-01-01

    X-ray-induced photo-chemistry of metal sites within biological molecules is a concern for X-ray absorption spectroscopy, X-ray crystallography and other techniques in which samples are illuminated with X-rays. The effects of X-ray-induced photo-chemistry are reviewed and the methods used to mitigate these in X-ray absorption spectroscopy are outlined.

  6. Handbook of X-Ray Astronomy

    Science.gov (United States)

    Arnaud, Keith A. (Editor); Smith, Randall K.; Siemiginowska, Aneta

    2011-01-01

    X-ray astronomy was born in the aftermath of World War II as military rockets were repurposed to lift radiation detectors above the atmosphere for a few minutes at a time. These early flights detected and studied X-ray emission from the Solar corona. The first sources beyond the Solar System were detected during a rocket flight in 1962 by a team headed by Riccardo Giaccom at American Science and Engineering, a company founded by physicists from MIT. The rocket used Geiger counters with a system designed to reduce non-X-ray backgrounds and collimators limiting the region of sky seen by the counters. As the rocket spun, the field of view (FOV) happened to pass over what was later found to be the brightest non-Solar X-ray source; later designated See X-1. It also detected a uniform background glow which could not be resolved into individual sources. A follow-up campaign using X-ray detectors with better spatial resolution and optical telescopes identified See X-1 as an interacting binary with a compact (neutron star) primary. This success led to further suborbital rocket flights by a number of groups. More X-ray binaries were discovered, as well as X-ray emission from supernova remnants, the radio galaxies M87 and Cygnus-A, and the Coma cluster. Detectors were improved and Geiger counters were replaced by proportional counters, which provided information about energy spectra of the sources. A constant challenge was determining precise positions of sources as only collimators were available.

  7. The use of alpha particle tagged neutrons for the inspection of objects on the sea floor for the presence of explosives

    International Nuclear Information System (INIS)

    A system using a neutron sensor installed within a Remotely Operated Vehicle (ROV) for underwater inspection has been developed. The system can inspect objects for the presence of threat materials, such as explosives and chemical agents, by using alpha particle tagged neutrons from a sealed tube d+t neutron generator to produce characteristic gamma rays within the interrogated object. Here we show that the measured gamma spectra for commonly found ammunition charged with TNT explosives are dominated by C, O and Fe peaks enabling the underwater determination of explosives inside an ammunition shell

  8. X-raying with low dose irradiation

    International Nuclear Information System (INIS)

    With the purpose of the improvement of diagnostics quality and reduction of beam load on a patient in modern x-ray devices pulse x-raying is applied. It is based on the using of radiation pulses with various frequencies of intervals between them instead of continuous radiation. At pulse x-raying with the net control the principle of filling of an interval is used, when the information about the image, received with the last pulse, get into memory and is displayed before occurrence of other pulse. It creates impression of the continuous image even at low frequency of pulses. Due to the unique concept of the simultaneous (double) control, all of 3 parameters, which define the quality of the image (pressure(voltage), force of a current and length of a pulse), are adjusted automatically at each pulse, thus optimum adaptation to varied thickness of object during dynamic researches occurs. At x-raying pulse the presence of a free interval from x-ray radiation between two pulses results in the decrease of a radiation dose. Pulsing occurs some times per one second with equal intervals between pulses. Thus, the degree of decrease irradiation dose depends on duration of a pause between pulses. On the screen the image of last pulse before occurrence of the following is kept and repeats. The principle of x-raying pulse was realized in system Grid Controlled Fluoroscopy by the firm 'Philips Medi zin Systeme'. In the x-ray tube of this system inclusion and de energizing of radiation occurs directly on a source. Electron cloud is broken off by the special grid, which is located between the cathode and the anode and operates as a barrier. Thus the tube continues to be energized. In usual devices for pulses formation is used generator pulsation system, which at increase and attenuation of a x-ray pulse results in occurrence of the increasing and fading radiation which are not participating in the formation of the image, but creating beam load on the patient and the personnel. Thus

  9. New achievements in X-ray optics——the X-ray lens and its applications

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    An X-ray lens consists of a large number of X-ray capillaries. It can collect divergent X-rays emitted from an X-ray source and form a focused or parallel beam of high intensity. So it is an effective tool for adjusting and controlling wide bandwidth X-ray beams. In this paper, the X-ray lens made by the X-ray Optics Laboratory of Institute of Low Energy Nuclear Physics at Beijing Normal University and its applications in the field of X-ray analysis are presented.

  10. Simultaneous x-rays/optical tomography of small animals

    Science.gov (United States)

    Da Silva, A.; Leabad, M.; Bordy, T.; Dinten, J.-M.; Peltié, P.; Rizo, P.

    2007-03-01

    A small animal multimodality tomographer dedicated to the co-registration of fluorescence optical signal and X-rays measurements has been developed in our laboratory. The purpose of such a system is to offer the possibility to get in vivo anatomical and functional information at once. Moreover, anatomical measurements can be used as a regularization factor in order to get the reconstructions of the biodistribution of fluorochromes more accurate and to speed up the treatment. The optical system is basically composed with a CW laser (Krypton, 752 nm) for an optimal excitation of Alexa-Fluor 750 fluorochromes, and a CCD camera coupled with a combination of filters for the fluorescence detection. The animal is placed inside a transparent tube filled with an index matching fluid. In order to perform multiple views of fluorescence data acquisitions, the cylinder is fixed to a rotating stage. The excitation beam is brought to the cylinder via two mirrors mounted on translation plates allowing a vertical scan. The optical data acquisitions are performed with a high sensitivity CCD camera. The X-ray generator and the X-ray detector have been placed perpendicularly to the optical chain. A first study on phantoms was conducted to evaluate the feasibility, to test the linearity and the reproducibility, and to fix the parameters for the co-registration. These test experiments were reproduced by considering mice in the oesophagus of which thin glass tubes containing fluorochromes were inserted. Finally, the performance of the system was evaluated in vivo on mice bearing tumours in the lungs, tagged with Transferin-AlexaFluor 750.

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

    Science.gov (United States)

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

    2013-10-01

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

  12. X-Ray Calorimeter Arrays for Astrophysics

    Science.gov (United States)

    Kilbourne, Caroline A.

    2009-01-01

    High-resolution x-ray spectroscopy is a powerful tool for studying the evolving universe. The grating spectrometers on the XMM and Chandra satellites started a new era in x-ray astronomy, but there remains a need for instrumentation that can provide higher spectral resolution with high throughput in the Fe-K band (around 6 keV) and can enable imaging spectroscopy of extended sources, such as supernova remnants and galaxy clusters. The instrumentation needed is a broad-band imaging spectrometer - basically an x-ray camera that can distinguish tens of thousands of x-ray colors. The potential benefits to astrophysics of using a low-temperature calorimeter to determine the energy of an incident x-ray photon via measurement of a small change in temperature was first articulated by S. H. Moseley over two decades ago. In the time since, technological progress has been steady, though full realization in an orbiting x-ray telescope is still awaited. A low-temperature calorimeter can be characterized by the type of thermometer it uses, and three types presently dominate the field. The first two types are temperature-sensitive resistors - semiconductors in the metal-insulator transition and superconductors operated in the superconducting-normal transition. The third type uses a paramagnetic thermometer. These types can be considered the three generations of x-ray calorimeters; by now each has demonstrated a resolving power of 2000 at 6 keV, but only a semiconductor calorimeter system has been developed to spaceflight readiness. The Soft X-ray Spectrometer on Astro-H, expected to launch in 2013, will use an array of silicon thermistors with I-IgTe x-ray absorbers that will operate at 50 mK. Both the semiconductor and superconductor calorimeters have been implemented in small arrays, kilo-pixel arrays of the superconducting calorimeters are just now being produced, and it is anticipated that much larger arrays will require the non-dissipative advantage of magnetic thermometers.

  13. X-ray spectroscopy an introduction

    CERN Document Server

    Agarwal, Bipin K

    1979-01-01

    Rontgen's discovery of X-rays in 1895 launched a subject which became central to the development of modern physics. The verification of many of the predic­ tions of quantum theory by X-ray spectroscopy in the early part of the twen­ tieth century stimulated great interest in thi's area, which has subsequently influenced fields as diverse as chemical physics, nuclear physics, and the study of the electronic properties of solids, and led to the development of techniques such as Auger, Raman, and X-ray photoelectron spectroscopy. The improvement of the theoretical understanding of the physics underlying X-ray spectroscopy has been accompanied by advances in experimental techniques, and the subject provides an instructive example of how progress on both these fronts can be mutually beneficial. This book strikes a balance between his­ torical description, which illustrates this symbiosis, and the discussion of new developments. The application of X-ray spectroscopic methods to the in­ vestigation of chemical b...

  14. Polarisation modulation in X-ray binaries

    Science.gov (United States)

    Ingram, Adam; Maccarone, Thomas

    2016-07-01

    X-ray polarimetry promises to provide a powerful new lever arm for studying accretion onto black holes with the next generation of X-ray telescopes. I will discuss how polarisation can be used to help constrain the physical origin of quasi-periodic oscillations (QPOs) observed in the X-ray light curves of accreting black holes. QPOs may be signatures of the frame dragging effect: in General Relativity, a spinning black hole twists up the surrounding space-time, causing vertical precession of nearby orbits. In the truncated disc / precessing inner flow model, the entire inner accretion flow precesses as a solid body causing a modulation in the X-ray flux through solid angle and Doppler effects. This model also predicts the observed polarisation of the X-ray signal to vary quasi-periodically. I will summarise our work to model the polarisation signal from a precessing accretion flow, starting with simple assumptions about the emission mechanism but taking General Relativity fully into account. We find that it should be possible to measure the predicted modulation in polarisation degree for a reasonable region of parameter space with a polarimeter capable of detecting ~60 counts per second from a bright black hole binary. I will also show that sensitivity can be greatly improved by correlating the signal with a high count rate reference band signal.

  15. Optics for coherent X-ray applications.

    Science.gov (United States)

    Yabashi, Makina; Tono, Kensuke; Mimura, Hidekazu; Matsuyama, Satoshi; Yamauchi, Kazuto; Tanaka, Takashi; Tanaka, Hitoshi; Tamasaku, Kenji; Ohashi, Haruhiko; Goto, Shunji; Ishikawa, Tetsuya

    2014-09-01

    Developments of X-ray optics for full utilization of diffraction-limited storage rings (DLSRs) are presented. The expected performance of DLSRs is introduced using the design parameters of SPring-8 II. To develop optical elements applicable to manipulation of coherent X-rays, advanced technologies on precise processing and metrology were invented. With propagation-based coherent X-rays at the 1 km beamline of SPring-8, a beryllium window fabricated with the physical-vapour-deposition method was found to have ideal speckle-free properties. The elastic emission machining method was utilized for developing reflective mirrors without distortion of the wavefronts. The method was further applied to production of diffraction-limited focusing mirrors generating the smallest spot size in the sub-10 nm regime. To enable production of ultra-intense nanobeams at DLSRs, a low-vibration cooling system for a high-heat-load monochromator and advanced diagnostic systems to characterize X-ray beam properties precisely were developed. Finally, new experimental schemes for combinative nano-analysis and spectroscopy realised with novel X-ray optics are discussed. PMID:25177986

  16. Nonlinear X-ray Compton Scattering

    CERN Document Server

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

    2015-01-01

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

  17. X-Ray Surveyor Mission Concept

    Science.gov (United States)

    Gaskin, Jessica

    2015-10-01

    An initial concept study for the X-ray Surveyor mission was carried-out by the Advanced Concept Office at Marshall Space Flight Center (MSFC), with a strawman payload and related requirements that were provided by an Informal Mission Concept Team, comprised of MSFC and Smithsonian Astrophysics Observatory (SAO) scientists plus a diverse cross-section of the X-ray community. The study included a detailed assessment of the requirements, a preliminary design, a mission analysis, and a preliminary cost estimate. The X-ray Surveyor strawman payload is comprised of a high-resolution mirror assembly and an instrument set, which may include an X-ray microcalorimeter, a high-definition imager, and a dispersive grating spectrometer and its readout. The mirror assembly will consist of highly nested, thin, grazing-incidence mirrors, for which a number of technical approaches are currently under development—including adjustable X-ray optics, differential deposition, and new polishing techniques applied to a variety of substrates. This study benefits from previous studies of large missions carried out over the past two decades, such as Con-X, AXSIO and IXO, and in most areas, points to mission requirements no more stringent than those of Chandra.

  18. Advanced X-ray diffractive optics

    Energy Technology Data Exchange (ETDEWEB)

    Vila-Comamala, J; Jefimovs, K; Sarkar, S S; Solak, H H; Guzenko, V A; Stampanoni, M; Marone, F; Raabe, J; Tzvetkov, G; Grolimund, D; Borca, C N; David, C [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Pilvi, T; Ritala, M [Department of Chemistry, FIN-00014 University of Helsinki (Finland); Fink, R H [Friedrich-Alexander Universitaet, D-91058 Erlangen (Germany); Kaulich, B, E-mail: joan.vila@psi.c [ELETTRA Sincrotrone, I-34012 Basovizza (Italy)

    2009-09-01

    X-ray microscopy greatly benefits from the advances in x-ray optics. At the Paul Scherrer Institut, developments in x-ray diffractive optics include the manufacture and optimization of Fresnel zone plates (FZPs) and diffractive optical elements for both soft and hard x-ray regimes. In particular, we demonstrate here a novel method for the production of ultra-high resolution FZPs. This technique is based on the deposition of a zone plate material (iridium) onto the sidewalls of a prepatterned template structure (silicon) by atomic layer deposition. This approach overcomes the limitations due to electron-beam writing of dense patterns in FZP fabrication and provides a clear route to push the resolution into sub-10 nm regime. A FZP fabricated by this method was used to resolve test structures with 12 nm lines and spaces at the scanning transmission x-ray microscope of the PolLux beamline of the Swiss Light Source at 1.2 keV photon energy.

  19. Thin Shell, Segmented X-Ray Mirrors

    Science.gov (United States)

    Petre, Robert

    2010-01-01

    Thin foil mirrors were introduced as a means of achieving high throughput in an X-ray astronomical imaging system in applications for which high angular resolution were not necessary. Since their introduction, their high filling factor, modest mass, relative ease of construction, and modest cost have led to their use in numerous X-ray observatories, including the Broad Band X-ray Telescope, ASCA, and Suzaku. The introduction of key innovations, including epoxy replicated surfaces, multilayer coatings, and glass mirror substrates, has led to performance improvements, and in their becoming widely used for X-ray astronomical imaging at energies above 10 keV. The use of glass substrates has also led to substantial improvement in angular resolution, and thus their incorporation into the NASA concept for the International X-ray Observatory with a planned 3 in diameter aperture. This paper traces the development of foil mirrors from their inception in the 1970's through their current and anticipated future applications.

  20. X-ray spectra for mamography

    International Nuclear Information System (INIS)

    By means of Monte Carlo methods the X-ray spectra that produce Mammography equipment have been obtained. The mammographs are widely used with the purpose of diagnosing the cancer of the mammary glands. Different makers and mammographs models are distinguished by the voltage capacity and the current, exist as well as in the target type and filter. The targets that are used are Mo, Rh and W and the filters are Mo, Rh, Al and Be. In this work the results obtained by means of the MCNP code of the X-ray spectra take place when an electron beam of 28 keV is made impact on Mo, Rh and W targets, as well as the spectra that result of filtering these X rays using different types of filters. The resulting spectra contain the continuous spectrum of the stopping radiation, as well as the X rays characteristic of the used target. The utility of estimating the spectra of X rays by means of Monte Carlo is that it can use to estimate the absorbed dose by the gland, as well as the absorbed dose by other organs. It also allows to calculate the detector response. (Author)