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Sample records for airborne lead x-ray

  1. Urban airborne lead: X-ray absorption spectroscopy establishes soil as dominant source.

    Directory of Open Access Journals (Sweden)

    Nicholas E Pingitore

    Full Text Available BACKGROUND: Despite the dramatic decrease in airborne lead over the past three decades, there are calls for regulatory limits on this potent pediatric neurotoxin lower even than the new (2008 US Environmental Protection Agency standard. To achieve further decreases in airborne lead, what sources would need to be decreased and what costs would ensue? Our aim was to identify and, if possible, quantify the major species (compounds of lead in recent ambient airborne particulate matter collected in El Paso, TX, USA. METHODOLOGY/PRINCIPAL FINDINGS: We used synchrotron-based XAFS (x-ray absorption fine structure to identify and quantify the major Pb species. XAFS provides molecular-level structural information about a specific element in a bulk sample. Pb-humate is the dominant form of lead in contemporary El Paso air. Pb-humate is a stable, sorbed complex produced exclusively in the humus fraction of Pb-contaminated soils; it also is the major lead species in El Paso soils. Thus such soil must be the dominant source, and its resuspension into the air, the transfer process, providing lead particles to the local air. CONCLUSIONS/SIGNIFICANCE: Current industrial and commercial activity apparently is not a major source of airborne lead in El Paso, and presumably other locales that have eliminated such traditional sources as leaded gasoline. Instead, local contaminated soil, legacy of earlier anthropogenic Pb releases, serves as a long-term reservoir that gradually leaks particulate lead to the atmosphere. Given the difficulty and expense of large-scale soil remediation or removal, fugitive soil likely constrains a lower limit for airborne lead levels in many urban settings.

  2. X-ray Scintillation in Lead Halide Perovskite Crystals

    OpenAIRE

    Birowosuto, M. D.; Cortecchia, D.; Drozdowski, W.; K. Brylew; Łachmański, W.; A. Bruno; Soci, C.

    2016-01-01

    Current technologies for X-ray detection rely on scintillation from expensive inorganic crystals grown at high-temperature, which so far has hindered the development of large-area scintillator arrays. Thanks to the presence of heavy atoms, solution-grown hybrid lead halide perovskite single crystals exhibit short X-ray absorption length and excellent detection efficiency. Here we compare X-ray scintillator characteristics of three-dimensional (3D) MAPbI3 and MAPbBr3 and two-dimensional (2D) (...

  3. X-ray Scintillation in Lead Halide Perovskite Crystals

    Science.gov (United States)

    Birowosuto, M. D.; Cortecchia, D.; Drozdowski, W.; Brylew, K.; Lachmanski, W.; Bruno, A.; Soci, C.

    2016-11-01

    Current technologies for X-ray detection rely on scintillation from expensive inorganic crystals grown at high-temperature, which so far has hindered the development of large-area scintillator arrays. Thanks to the presence of heavy atoms, solution-grown hybrid lead halide perovskite single crystals exhibit short X-ray absorption length and excellent detection efficiency. Here we compare X-ray scintillator characteristics of three-dimensional (3D) MAPbI3 and MAPbBr3 and two-dimensional (2D) (EDBE)PbCl4 hybrid perovskite crystals. X-ray excited thermoluminescence measurements indicate the absence of deep traps and a very small density of shallow trap states, which lessens after-glow effects. All perovskite single crystals exhibit high X-ray excited luminescence yields of >120,000 photons/MeV at low temperature. Although thermal quenching is significant at room temperature, the large exciton binding energy of 2D (EDBE)PbCl4 significantly reduces thermal effects compared to 3D perovskites, and moderate light yield of 9,000 photons/MeV can be achieved even at room temperature. This highlights the potential of 2D metal halide perovskites for large-area and low-cost scintillator devices for medical, security and scientific applications.

  4. X-ray Scintillation in Lead Halide Perovskite Crystals

    CERN Document Server

    Birowosuto, M D; Drozdowski, W; Brylew, K; Lachmanski, W; Bruno, A; Soci, C

    2016-01-01

    Current technologies for X-ray detection rely on scintillation from expensive inorganic crystals grown at high-temperature, which so far has hindered the development of large-area scintillator arrays. Thanks to the presence of heavy atoms, solution-grown hybrid lead halide perovskite single crystals exhibit short X-ray absorption length and excellent detection efficiency. Here we compare X-ray scintillator characteristics of three-dimensional (3D) MAPbI3 and MAPbBr3 and two-dimensional (2D) (EDBE)PbCl4 hybrid perovskite crystals. X-ray excited thermoluminescence measurements indicate the absence of deep traps and a very small density of shallow trap states, which lessens after-glow effects. All perovskite single crystals exhibit high X-ray excited luminescence yields of >120,000 photons/MeV at low temperature. Although thermal quenching is significant at room temperature, the large exciton binding energy of 2D (EDBE)PbCl4 significantly reduces thermal effects compared to 3D perovskites, and moderate light yie...

  5. Sensitive X-ray detectors made of methylammonium lead tribromide perovskite single crystals

    NARCIS (Netherlands)

    Wei, Haotong; Fang, Yanjun; Mulligan, Padhraic; Chuirazzi, William; Fang, Hong-Hua; Wang, Congcong; Ecker, Benjamin R.; Gao, Yongli; Loi, Maria Antonietta; Cao, Lei; Huang, Jinsong

    2016-01-01

    The large mobilities and carrier lifetimes of hybrid perovskite single crystals and the high atomic numbers of Pb, I and Br make them ideal for X-ray and gamma-ray detection. Here, we report a sensitive X-ray detector made of methylammonium lead bromide perovskite single crystals. A record-high mobi

  6. Structural characterization of lead sulfide thin films by means of X-ray line profile analysis

    Indian Academy of Sciences (India)

    N Choudhury; B K Sarma

    2009-02-01

    X-ray diffraction patterns of chemically deposited lead sulphide thin films have been recorded and X-ray line profile analysis studies have been carried out. The lattice parameter, crystallite size, average internal stress and microstrain in the film are calculated and correlated with molarities of the solutions. Both size and strain are found to contribute towards the broadening of X-ray diffraction line. The values of the crystallite size are found to be within the range from 22–33 nm and the values of strain to be within the range from 1.0 × 10-3–2.5 × 10-3.

  7. Soft X-ray-assisted detection method for airborne molecular contaminations (AMCs)

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Changhyuk; Zuo, Zhili [University of Minnesota, Department of Mechanical Engineering (United States); Finger, Hartmut; Haep, Stefan; Asbach, Christof; Fissan, Heinz [Institute of Energy and Environmental Technology (IUTA e. V.) (Germany); Pui, David Y. H., E-mail: dyhpui@umn.edu [University of Minnesota, Department of Mechanical Engineering (United States)

    2015-03-15

    Airborne molecular contaminations (AMCs) represent a wide range of gaseous contaminants in cleanrooms. Due to the unintentional nanoparticle or haze formation as well as doping caused by AMCs, improved monitoring and controlling methods for AMCs are urgent in the semiconductor industry. However, measuring ultra-low concentrations of AMCs in cleanrooms is difficult, especially, behind a gas filter. In this study, a novel detection method for AMCs, which is on-line, economical, and applicable for diverse AMCs, was developed by employing gas-to-particle conversion with soft X-ray, and then measuring the generated nanoparticles. Feasibility study of this method was conducted through the evaluations of granular-activated carbons (GACs), which are widely used AMC filter media. Sulfur dioxide (SO{sub 2}) was used as an AMC for the feasibility study. Using this method, the ultra-low concentrations of SO{sub 2} behind GACs were determined in terms of concentrations of generated sulfuric acid (H{sub 2}SO{sub 4}) nanoparticles. By calculating SO{sub 2} concentrations from the nanoparticle concentrations using empirical correlation equations between them, remarkable sensitivity of this method to SO{sub 2} was shown, down to parts-per-trillions, which are too low to detect using commercial gas sensors. Also, the calculated SO{sub 2} concentrations showed good agreement with those measured simultaneously by a commercial SO{sub 2} monitor at parts-per-billions.

  8. Sensitive X-ray detectors made of methylammonium lead tribromide perovskite single crystals

    Science.gov (United States)

    Wei, Haotong; Fang, Yanjun; Mulligan, Padhraic; Chuirazzi, William; Fang, Hong-Hua; Wang, Congcong; Ecker, Benjamin R.; Gao, Yongli; Loi, Maria Antonietta; Cao, Lei; Huang, Jinsong

    2016-05-01

    The large mobilities and carrier lifetimes of hybrid perovskite single crystals and the high atomic numbers of Pb, I and Br make them ideal for X-ray and gamma-ray detection. Here, we report a sensitive X-ray detector made of methylammonium lead bromide perovskite single crystals. A record-high mobility-lifetime product of 1.2 × 10-2 cm2 V-1 and an extremely small surface charge recombination velocity of 64 cm s-1 are realized by reducing the bulk defects and passivating surface traps. Single-crystal devices with a thickness of 2-3 mm show 16.4% detection efficiency at near zero bias under irradiation with continuum X-ray energy up to 50 keV. The lowest detectable X-ray dose rate is 0.5 μGyair s-1 with a sensitivity of 80 μC Gy-1air cm-2, which is four times higher than the sensitivity achieved with α-Se X-ray detectors. This allows the radiation dose applied to a human body to be reduced for many medical and security check applications.

  9. Diffuse X-ray scattering and far infrared absorption of barium and lead β" aluminas

    DEFF Research Database (Denmark)

    Hayes, W.; Kjær, Kristian; Pratt, F. L.;

    1985-01-01

    The authors have carried out high-momentum-resolution studies in diffuse X-ray scattering of barium and lead B" aluminas in the temperature range 20-700 degrees C. They have also measured the vibrational spectra of these compounds between 2K and 300K in the energy range 10-100 cm-1. The results a...

  10. Uncertainty calculations for the measurement of in vivo bone lead by x-ray fluorescence.

    Science.gov (United States)

    O'Meara, J M; Fleming, D E B

    2009-04-21

    In order to quantify the bone lead concentration from an in vivo x-ray fluorescence measurement, typically two estimates of the lead concentration are determined by comparing the normalized x-ray peak amplitudes from the Kalpha(1) and Kbeta(1) features to those of the calibration phantoms. In each case, the normalization consists of taking the ratio of the x-ray peak amplitude to the amplitude of the coherently scattered photon peak in the spectrum. These two Pb concentration estimates are then used to determine the weighted mean lead concentration of that sample. In calculating the uncertainties of these measurements, it is important to include any covariance terms where appropriate. When determining the uncertainty of the lead concentrations from each x-ray peak, the standard approach does not include covariance between the x-ray peaks and the coherently scattered feature. These spectral features originate from two distinct physical processes, and therefore no covariance between these features can exist. Through experimental and simulated data, we confirm that there is no observed covariance between the detected Pb x-ray peaks and the coherently scattered photon signal, as expected. This is in direct contrast to recent work published by Brito (2006 Phys. Med. Biol. 51 6125-39). There is, however, covariance introduced in the calculation of the weighted mean lead concentration due to the common coherent normalization. This must be accounted for in calculating the uncertainty of the weighted mean lead concentration, as is currently the case. We propose here an alternative approach to calculating the weighted mean lead concentration in such a way as to eliminate the covariance introduced by the common coherent normalization. It should be emphasized that this alternative approach will only apply in situations in which the calibration line intercept is not included in the calculation of the Pb concentration from the spectral data: when the source of the intercept is

  11. Detection of X-ray photons by solution-processed lead halide perovskites

    Science.gov (United States)

    Yakunin, Sergii; Sytnyk, Mykhailo; Kriegner, Dominik; Shrestha, Shreetu; Richter, Moses; Matt, Gebhard J.; Azimi, Hamed; Brabec, Christoph J.; Stangl, Julian; Kovalenko, Maksym V.; Heiss, Wolfgang

    2015-07-01

    The evolution of real-time medical diagnostic tools such as angiography and computer tomography from radiography based on photographic plates was enabled by the development of integrated solid-state X-ray photon detectors made from conventional solid-state semiconductors. Recently, for optoelectronic devices operating in the visible and near-infrared spectral regions, solution-processed organic and inorganic semiconductors have also attracted a great deal of attention. Here, we demonstrate a possibility to use such inexpensive semiconductors for the sensitive detection of X-ray photons by direct photon-to-current conversion. In particular, methylammonium lead iodide perovskite (CH3NH3PbI3) offers a compelling combination of fast photoresponse and a high absorption cross-section for X-rays, owing to the heavy Pb and I atoms. Solution-processed photodiodes as well as photoconductors are presented, exhibiting high values of X-ray sensitivity (up to 25 μC mGyair-1 cm-3) and responsivity (1.9 × 104 carriers/photon), which are commensurate with those obtained by the current solid-state technology.

  12. [Shielding evaluation of lead-free board for diagnostic X-rays].

    Science.gov (United States)

    Katoh, Yoh; Tsukada, Masaru; Mita, Sogo; Fukushi, Masahiro; Nyui, Yoshiyuki; Abe, Shinji; Kimura, Junichi

    2010-12-20

    For physical foundation data used in the shielding calculation of structural facilities such as a radiation room, there are air kerma transmissions concerning the thickness of shielding objects, and half value layers and tenth value layers concerning a greatly attenuated wide X-ray beam. Accordingly, we evaluated the above-mentioned items with a lead-free board, which is mixed sulfuric acid calcium and barium sulfate with equiponderance for the amount of sulfuric acid calcium included in the usual plasterboard. Permeability in NCRP Report 147 is expressed by 3 parameters, α, β and γ, and shielding objects x. It showed that it corresponds to the measurement point and permeability curve with parameters, α, β and γ obtained by nonlinear regression analysis. Furthermore, we calculated the half value layer and tenth value layer concerning the greatly attenuated wide X-ray beam. The evaluated lead-free board, used in this examination, is useful as the shielding material for the diagnosis X-ray and, moreover, the partition wall materials are hard enough, with a board that is even heavier than the usual plaster board. Besides, the use of lead-free materials is friendly to the general environment.

  13. Quantitative x-ray diffraction phase analysis of coarse airborne particulate collected by cascade impactor sampling

    Science.gov (United States)

    Esteve, V.; Rius, J.; Ochando, L. E.; Amigó, J. M.

    Mineralogical composition of Castellon (Spanish Mediterranean coast) atmospheric aerosol was studied by X-ray diffraction by sampling with a cascade impactor without filters. Quantitative phase analysis of natural phases present in the atmospheric coarse aerosol was performed using a modified version of the computer program MENGE, that uses the standardless X-ray method developed by Rius for the quantitative analysis of multiphase mixtures, adapted for PC running. Presence of quartz, calcite and gypsum was identified in the atmospheric aerosol and we have quantified their amounts using the standardless method.

  14. Estimation of Lead (Pb in Toys Using X-Ray Fluorescence Technology

    Directory of Open Access Journals (Sweden)

    Sandipayan Dutta

    2016-01-01

    Full Text Available Background: Lead exists extensively in the environment and it is a heavy metal, which is neurotoxic in nature which is harmful to children. In contrast to trace elements such as iron (Fe and zinc (Zn, lead has no recognized benecial effects in human body. With the economic development in India in recent years, the concentration of lead has increased in the environment and henceforth, lead pollution has become a severe problem in the country. Lead poisoning can create an immense damage and irreversible harm to foetal growth, the growth of teenagers and psychological, behavioural and cognitive development. Aim and Objectives: To estimate the lead content in the sample of toys. Material and Methods: 97 different toys were collected and coded as TS, these toys were kept in plastic lock cover which were lead proof. At rst the toys were arranged in order according to the serial number of the code (TS1 – TS97. The FP X-ray uorescence (Innov-X ray analyzer instrument was placed with the window of the analyzer on the surface of the toy vertically in such a way that there was no gap between the toy surface and the sampling window. The parts per million (ppm values of all toys were recorded. Results: Out of 97 samples tested, 22 samples were above permissible limits. The different materials demonstrate signicant correlation with the lead content in ppm. Lead is used as a stabilizer in some toys as well as children's items made from PVC plastic. Baby toys made up of plastic have higher concentration of lead. Lead can leach out of products when children handle and swallow them involuntarily.

  15. High resolution X-ray diffraction imaging of lead tin telluride

    Science.gov (United States)

    Steiner, Bruce; Dobbyn, Ronald C.; Black, David; Burdette, Harold; Kuriyama, Masao; Spal, Richard; Simchick, Richard; Fripp, Archibald

    1991-01-01

    High resolution X-ray diffraction images of two directly comparable crystals of lead tin telluride, one Bridgman-grown on Space Shuttle STS 61A and the other terrestrially Bridgman-grown under similar conditions from identical material, present different subgrain structure. In the terrestrial, sample 1 the appearance of an elaborate array of subgrains is closely associated with the intrusion of regions that are out of diffraction in all of the various images. The formation of this elaborate subgrain structure is inhibited by growth in microgravity.

  16. Characterization of thermally evaporated lead iodide films aimed for the detection of X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Caldeira Filho, A.M. [Departamento de Fisica, Faculdade de Filosofia, Ciencias e Letras de Ribeirao Preto, Universidade de Sao Paulo - USP, Avenida Bandeirantes 3900, 14040-901, Ribeirao Preto-SP (Brazil); Mulato, M., E-mail: mmulato@ffclrp.usp.b [Departamento de Fisica, Faculdade de Filosofia, Ciencias e Letras de Ribeirao Preto, Universidade de Sao Paulo - USP, Avenida Bandeirantes 3900, 14040-901, Ribeirao Preto-SP (Brazil)

    2011-04-21

    Some semiconductor materials such as lead iodide (PbI{sub 2}) have applications in the detection of ionizing radiation at room temperature using the direct detection method. In this work we investigate lead iodide films deposited by thermal evaporation. The morphology, structure, and electric properties were investigated as a function of deposition height, i.e. the distance between evaporation-boat and substrates. The results show a morphology of vertical leaves and X-ray diffraction shows just one preferential orientation along the direction 110. Energy dispersive spectroscopy reveals that the films are not stoichiometric, with excess iodine atoms. Electrical resistivity of about 10{sup 8} {Omega} cm was measured. This is smaller than for the bulk due to structural defects. The values of activation energy for electric transport increase from 0.52 up to 1.1 eV with decreasing deposition height, what indicates that the best film is the one deposited at the shortest distance. Exposure under X-ray mammographic energy shows a linear behavior up to 500 mR. No variation in sensibility was observed between 22 and 30 kVp.

  17. Tibial lead determination by 99Tcm radiopharmaceutical x-ray fluorescence.

    Science.gov (United States)

    Mountford, P J; Green, S; Bradley, D A; Lewis, A D; Morgan, W D

    1994-04-01

    The feasibility of measuring tibial lead concentration by x-ray fluorescence with an internal 99Tcm labelled bone-seeking radiopharmaceutical was investigated using phantoms containing known values of lead concentration and 99Tcm activity. The minimum detectable concentration (MDC) at two standard deviations based on the counts in the Kalpha1 peak of 10.9 microg Pb ml(-1) was estimated to correspond to an MDC for an individual within a range of approximately 8-15 microg Pb (g bone mineral)(-1) if the counts from all four K x-ray peaks were included. Due to its much greater dose compared to an external source, the MDC of this internal source technique would have to be reduced before it could be used for measurements of occupationally or environmentally exposed individuals other than as an adjunct for a patient undergoing a bone scan. Methods of achieving such a reduction include increasing the acquisition time and the number of HPGE detectors, and optimizing the design of their collimators.

  18. Nanoscale Images of Airborne PM2.5: Aerosol Dynamics with the LCLS X-ray Laser

    Science.gov (United States)

    Bogan, M. J.

    2012-12-01

    It is now possible to capture images of individual airborne PM2.5 particles - including soot, NaCl particles and engineered nanoparticles - with 20-40 nm resolution (Loh et al Nature 2012). Ions released during the imaging process provide information on the chemical content of the isolated particles. The scattering signal used to compose the image also provides the fractal dimension of individual particles. This new paradigm of aerosol dynamics is enabled by the incredible brightness and ultrashort pulses available at X-ray free electron laser (FEL) facilities, such as the Linac Coherent Light Source (LCLS) and the FLASH FEL facility in Hamburg. Femtosecond long x-ray pulses deliver sufficient photons (10^12 per pulse) to detect scattered X-rays off individual particles injected at >100 m/s into vacuum through an aerodynamic lens stack. The intensity of the scattered X-rays measured by an area detector is fed into lensless imaging algorithms to reconstruct an image of the particle that caused the scattering. X-ray FELs can peer inside the individual airborne particles and are a sensitive probe of particle crystallinity. The development of this method and applications to imaging micron-sized soot, water droplets and biological aerosols will be discussed. A primary long-term goal of the research is to take snapshots of airborne particles as they change their size, shape and chemical make-up in response to their environment. "Fractal morphology, imaging and mass spectrometry of single aerosol particles in flight" ND Loh, C Hampton, A Martin, D Starodub, R Sierra, A Barty, A Aquila, J Schulz, L Lomb, J Steinbrener, R Shoeman, S Kassemeyer, C Bostedt, J. Bozek, S Epp, B. Erk, R Hartmann, D Rolles, A Rudenko, B Rudek, L Foucar, N Kimmel, G Weidenspointner, G Hauser, P Holl, E. Pedersoli, M Liang, M Hunter, L Gumprecht, N Coppola, C Wunderer, H Graafsma, F Maia, T Ekeberg, M Hantke, H Fleckenstein, H. Hirsemann, K Nass, T White, H Tobias, G Farquar, W Benner, S Hau

  19. Lead iodide X-ray and gamma-ray spectrometers for room and high temperature operation

    Energy Technology Data Exchange (ETDEWEB)

    Hermon, H.; James, R.B.; Cross, E. [and others

    1997-02-01

    In this study, we report on the results of the investigation of lead iodide material properties. The effectiveness of zone refining purification methods on the material purity is determined by ICP-MS and ICP-OES and correlated to the electrical and physical material properties. We show that this zone refining method is very efficient in removing impurities from lead iodide and we also determine the segregation coefficient for some of these impurities. Triple axis x- ray diffraction (TAD) analysis has been used to determine the crystalline perfection of the lead iodide after applying various cutting, etching, and fabrication methods. The soft lead iodide crystal was found to be damaged when cleaved by a razor blade, but by using a diamond wheel saw, followed by etching, the crystallinity of the material was improved, as observed by TAD. Low temperature photoluminescence also indicates an improvement in the material properties of the purified lead iodide. Electrical properties of lead iodide such as carrier mobility, were calculated based on carrier- phonon scattering. The results for the electrical properties were in good agreement with the experimental data.

  20. Identification of lead chemical form in mine waste materials by X-ray absorption spectroscopy

    Science.gov (United States)

    Taga, Raijeli L.; Zheng, Jiajia; Huynh, Trang; Ng, Jack; Harris, Hugh H.; Noller, Barry

    2010-06-01

    X-ray absorption spectroscopy (XAS) provides a direct means for measuring lead chemical forms in complex samples. In this study, XAS was used to identify the presence of plumbojarosite (PbFe6(SO4)4(OH)12) by lead L3-edge XANES spectra in mine waste from a small gold mining operation in Fiji. The presence of plumbojarosite in tailings was confirmed by XRD but XANES gave better resolution. The potential for human uptake of Pb from tailings was measured using a physiologically based extract test (PBET), an in-vitro bioaccessibility (BAc) method. The BAc of Pb was 55%. Particle size distribution of tailings indicated that 40% of PM10 particulates exist which could be a potential risk for respiratory effects via the inhalation route. Food items collected in the proximity of the mine site had lead concentrations which exceed food standard guidelines. Lead within the mining lease exceeded sediment guidelines. The results from this study are used to investigate exposure pathways via ingestion and inhalation for potential risk exposure pathways of Pb in that locality. The highest Pb concentration in soil and tailings was 25,839 mg/kg, exceeding the Australian National Environment Protection Measure (NEPM) soil health investigation levels.

  1. X-ray fluorescence for quantification of lead and strontium in vivo

    Science.gov (United States)

    Specht, Aaron James

    Lead (Pb) is a toxicant well known for its effects on almost every organ system in the body. Pb use in industry has declined since removal of Pb from gasoline, but many developing countries still have significant use of Pb. Exposure to Pb has been linked with diseases causing neurodegeneration and thus have lasting effects long after the initial exposure. Another metal, strontium (Sr), has been linked with bone disease in particular situations and shown to have uses in treating osteoporosis as a supplement. However, there are no studies of the effects of Sr using a meaningful biomarker. The most commonly used biomarkers for Pb and Sr exposures are blood Pb and Sr; however, blood tests are unable to identify long-term exposure levels due to the short half-life of these metals in blood. Bone stores of Pb and Sr have a half-life of years to decades and serve as a biomarker of long-term exposure. X-ray fluorescence has been used to measure bone Pb and Sr. However, current systems have limitations with radioisotope sources, bulky equipment, and long measurement times. A portable XRF device capable of measurement of bone Pb and Sr, overcomes the limitation of the current systems and has been developed in this work. The detection limit of the portable XRF for bone Pb and Sr was found to be 11 ppm and 5 ppm respectively at 5 mm of skin thickness. The portable XRF will have limitations of measurement based on an individual's skin thickness. The device was calibrated using standard phantoms and validated with in-lab samples, which demonstrated good agreement between KXRF and portable XRF measurements with strong correlations between goat bone, cadaver bone, and phantom measurements. In a population study of Pb poisoned children the portable XRF was further validated and a significant correlation between KXRF measured bone Pb and portable XRF measured bone Pb was identified; however, the device had limitations based on anatomical differences unaccounted for in children from

  2. 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.

  3. Polycrystalline lead iodide films produced by solution evaporation and tested in the mammography X-ray energy range

    Science.gov (United States)

    Condeles, J. F.; Mulato, M.

    2016-02-01

    Lead iodide polycrystalline films have been deposited on corning glass substrates using solution evaporation in oven. Films 6 μm-thick were obtained with full coverage of the substrates as verified by scanning electron microscopy. Some pin-holes were observable. X-ray diffraction revealed a crystalline structure corresponding to the 4 H-PbI2 polytype formation. Polarized Raman scattering experiments indicated a lamellar structure. Anisotropy was also investigated using depolarization ratio calculations. The optical and electrical properties of the samples were investigated using photoluminescence and dark conductivity as a function of temperature, respectively. Activation energies of 0.10 up to 0.89 eV were related to two main electrical transport mechanisms. Films were also exposed to X-ray irradiation in the mammography X-ray energy range. The detector produced was also exposed to X-ray from 5 mR up to 1450 mR. A linear response was observed as a function of dose with a slope of 0.52 nA/mm2 per mR.

  4. Use of a field portable X-Ray fluorescence analyzer to determine the concentration of lead and other metals in soil samples.

    Science.gov (United States)

    Clark, S; Menrath, W; Chen, M; Roda, S; Succop, P

    1999-01-01

    Field portable methods are often needed in risk characterization, assessment and management to rapidly determine metal concentrations in environmental samples. Examples are for determining: "hot spots" of soil contamination, whether dust wipe lead levels meet housing occupancy standards, and worker respiratory protection levels. For over 30 years portable X-Ray Fluorescence (XRF) analyzers have been available for the in situ, non-destructive, measurement of lead in paint. Recent advances made possible their use for analysis of airborne dust filter samples, soil, and dust wipes. Research at the University of Cincinnati with the NITON 700 Series XRF instrument (40 millicurie Cadmium 109 source, L X-Rays) demonstrated its proficiency on air sample filters (NIOSH Method No. 7702, "Lead by Field Portable XRF; limit of detection 6 microg per sample; working range 17-1,500 microg/m3 air). Research with lead dust wipe samples from housing has also shown promising results. This XRF instrument was used in 1997 in Poland on copper smelter area soil samples with the cooperation of the Wroclaw Medical Academy and the Foundation for the Children from the Copper Basin (Legnica). Geometric mean soil lead concentrations were 200 ppm with the portable XRF, 201 ppm with laboratory-based XRF (Kevex) and 190 ppm using atomic absorption (AA). Correlations of field portable XRF and AA results were excellent for samples sieved to less than 125 micrometers with R-squared values of 0.997, 0.957, and 0.976 for lead, copper and zinc respectively. Similarly, correlations were excellent for soil sieved to less than 250 micrometers, where R-squared values were 0. 924, 0.973, and 0.937 for lead, copper and zinc, respectively. The field portable XRF instrument appears to be useful for the determination of soil pollution by these metals in industrial regions.

  5. Observation of electric quadrupole X-ray transitions in muonic thallium, lead and bismuth

    CERN Document Server

    Schneuwly, H; Engfer, R; Jahnke, U; Kankeleit, E; Lindenberger, K H; Pearce, R M; Petitjean, C; Schellenberg, L; Schröder, W U; Walter, H K; Zehnder, A

    1972-01-01

    Electric quadrupole X-ray transitions (5g to 3d, 4f to 2p, and 3d to 1s) have been observed in muonic Tl, Pb and Bi. From the 3 to 1 transitions, energy splittings of the n=3 levels were deduced. From a comparison of the relative intensities of E1 and E2 transitions the population ratios 5g/5f, 4f/4d, and 3d/3p were deduced. These ratios are well reproduced by a cascade calculation assuming a statistical initial population at n=20, including K, L and M shell conversion. In the case of /sup 205/Tl discrepancies between the experimental and the calculated 3d-1s/3p-is intensity ratio can be explained by nuclear excitation. From the 3p/sub 3/2/ to 1s/sub 1/2/ intensity in /sup 209 /Bi one can deduce the ratio of the radiationless to the X-ray transition width and give limits for prompt neutron emission from the 3d level. (23 refs).

  6. Structural analysis of lead magnesium niobate using synchrotron powder X-ray diffraction and the Rietveld method.

    Science.gov (United States)

    Bhakar, Ashok; Pandey, Adityanarayan H; Singh, M N; Upadhyay, Anuj; Sinha, A K; Gupta, S M; Ganguli, Tapas

    2016-06-01

    The room-temperature synchrotron powder X-ray diffraction pattern of the single phase perovskite lead magnesium niobate (PMN) has shown significant broadening in the q range ∼ 5-7 Å(-1) compared with standard LaB6 synchrotron powder X-ray diffraction data, taken under similar conditions. This broadening/asymmetry lies mainly towards the lower 2θ side of the Bragg peaks. Attempts to fit this data with the paraelectric cubic phase (Pm\\bar 3m) and the local rhombohedral phase (R3m) corresponding to polar nanoregions (PNRs) are made using the Rietveld method. Rietveld refinements show that neither cubic (Pm\\bar 3m) nor rhombohedral (R3m) symmetry can fit this XRD pattern satisfactorily. The two-phase refinement fits the experimental data satisfactorily and suggests that the weight percentage of the PNRs is approximately 12-16% at room temperature. The unit-cell volume of these rhombohedral PNRs is approximately 0.15% larger than that of the unit cell volume of the paraelectric cubic phase.

  7. Advanced X-Ray Inspection of Reinforced Carbon Composite Materials on the Orbiter Leading Edge Structural Subsystem (LESS)

    Science.gov (United States)

    Hernandez, Jose M.; Berry, Robert F.; Osborn, Robin; Bueno, Clifford; Osterlitz, Mark; Mills, Richard; Morris, Philip; Phalen, Robert; McNab, Jim; Thibodeaux, Tahanie; Thompson, Kyle

    2004-01-01

    The post return-to-flight (RTF) inspection methodology for the Orbiter Leading Edge Structural Subsystem (LESS) is currently being defined. Numerous NDT modalities and techniques are being explored to perform the flight-to-flight inspections of the reinforced carbon/carbon (RCC) composite material for impact damage, general loss of mass in the bulk layers, or other anomalous conditions that would pose risk to safe return upon re-entry. It is possible to have an impact upon ascent that is not visually observable on the surface, yet causes internal damage. Radiographic testing may be a useful NDT technique for such occurrences. The authors have performed radiographic tests on full-sized mock samples of LESS hardware with embedded image quality phantoms. Digitized radiographic film, computed radiography and flat panel digital real-time radiography was acquired using a GE Eresco 200 x-ray tube, and Se-75 and Yb-169 radioisotopes.

  8. Carbon nanotubes allow capture of krypton, barium and lead for multichannel biological X-ray fluorescence imaging

    Science.gov (United States)

    Serpell, Christopher J.; Rutte, Reida N.; Geraki, Kalotina; Pach, Elzbieta; Martincic, Markus; Kierkowicz, Magdalena; de Munari, Sonia; Wals, Kim; Raj, Ritu; Ballesteros, Belén; Tobias, Gerard; Anthony, Daniel C.; Davis, Benjamin G.

    2016-10-01

    The desire to study biology in situ has been aided by many imaging techniques. Among these, X-ray fluorescence (XRF) mapping permits observation of elemental distributions in a multichannel manner. However, XRF imaging is underused, in part, because of the difficulty in interpreting maps without an underlying cellular `blueprint' this could be supplied using contrast agents. Carbon nanotubes (CNTs) can be filled with a wide range of inorganic materials, and thus can be used as `contrast agents' if biologically absent elements are encapsulated. Here we show that sealed single-walled CNTs filled with lead, barium and even krypton can be produced, and externally decorated with peptides to provide affinity for sub-cellular targets. The agents are able to highlight specific organelles in multiplexed XRF mapping, and are, in principle, a general and versatile tool for this, and other modes of biological imaging.

  9. Lead uptake in diverse plant families: a study applying X-ray absorption near edge spectroscopy.

    Science.gov (United States)

    Bovenkamp, Gudrun L; Prange, Alexander; Schumacher, Wolfgang; Ham, Kyungmin; Smith, Aaron P; Hormes, Josef

    2013-05-07

    The chemical environment of lead in roots and leaves of plants from four different plant families and a lichen from a former lead mining site in the Eifel Mountains in Germany was determined by Pb L3-edge XANES measurements using solid reference compounds and also aqueous solutions of different ionic strength simulating the plant environment. Pb(2+) ions in the plants were found to have two major coordinations, one with nine oxygen atoms in the first coordination shell similar to outer-sphere complexation and a second coordination with just three oxygen atoms similar to inner-sphere complexation. This can be interpreted assuming that lead is sorbed on the surface of cell walls depending on the concentration of lead in the soil solution. Pb L3-edge XANES spectra of dried and fresh plant samples are very similar because sorption does not change with removal of water but only because of the initial ionic strength. No bonding to biologically important groups (-S, - N) or precipitation (-PO4) was found.

  10. Study of lead accumulation in bones of Wistar rats by X-ray fluorescence analysis: aging effect.

    Science.gov (United States)

    Guimarães, Diana; Carvalho, Maria Luísa; Geraldes, Vera; Rocha, Isabel; Santos, José Paulo

    2012-01-01

    The accumulation of lead in several bones of Wistar rats with time was determined and compared for the different types of bones. Two groups were studied: a control group (n = 20), not exposed to lead and a contaminated group (n = 30), exposed to lead from birth, first indirectly through mother's milk, and then directly through a diet containing lead acetate in drinking water (0.2%). Rats age ranged from 1 to 11 months, with approximately 1 month intervals and each of the collections had 3 contaminated rats and 2 control rats. Iliac, femur, tibia-fibula and skull have been analysed by Energy Dispersive X-ray Fluorescence Technique (EDXRF). Samples of formaldehyde used to preserve the bone tissues were also analysed by Electrothermal Atomic Absorption (ETAAS), showing that there was no significant loss of lead from the tissue to the preservative. The bones mean lead concentration of exposed rats range from 100 to 300 μg g(-1) while control rats never exceeded 10 μg g(-1). Mean bone lead concentrations were compared and the concentrations were higher in iliac, femur and tibia-fibula and after that skull. However, of all the concentrations in the different collections, only those in the skull were statistically significantly different (p bones. Analysis of a radar chart also allowed us to say that these differences tend to diminish with age. The Spearman correlation test applied to mean lead concentrations showed strong and very strong positive correlations between all different types of bones. This test also showed that mean lead concentrations in bones are negatively correlated with the age of the animals. This correlation is strong in iliac and femur and very strong in tibia-fibula and skull. It was also shown that the decrease of lead accumulation with age is made by three plateaus of accumulation, which coincide, in all analysed bones, between 2nd-3rd and 9th-10th months.

  11. Dosimetry study for a new in vivo X-ray fluorescence (XRF) bone lead measurement system

    Science.gov (United States)

    Nie, Huiling; Chettle, David; Luo, Liqiang; O'Meara, Joanne

    2007-10-01

    A new 109Cd γ-ray induced bone lead measurement system has been developed to reduce the minimum detectable limit (MDL) of the system. The system consists of four 16 mm diameter detectors. It requires a stronger source compared to the "conventional" system. A dosimetry study has been performed to estimate the dose delivered by this system. The study was carried out by using human-equivalent phantoms. Three sets of phantoms were made to estimate the dose delivered to three age groups: 5-year old, 10-year old and adults. Three approaches have been applied to evaluate the dose: calculations, Monte Carlo (MC) simulations, and experiments. Experimental results and analytical calculations were used to validate MC simulation. The experiments were performed by placing Panasonic UD-803AS TLDs at different places in phantoms that representing different organs. Due to the difficulty of obtaining the organ dose and the whole body dose solely by experiments and traditional calculations, the equivalent dose and effective dose were calculated by MC simulations. The result showed that the doses delivered to the organs other than the targeted lower leg are negligibly small. The total effective doses to the three age groups are 8.45/9.37 μSv (female/male), 4.20 μSv, and 0.26 μSv for 5-year old, 10-year old and adult, respectively. An approval to conduct human measurements on this system has been received from the Research Ethics Board based on this research.

  12. The impact of EDTA on lead distribution and speciation in the accumulator Sedum alfredii by synchrotron X-ray investigation.

    Science.gov (United States)

    Tian, Sheng-ke; Lu, Ling-li; Yang, Xiao-e; Huang, Hua-gang; Brown, Patrick; Labavitch, John; Liao, Hai-bing; He, Zhen-li

    2011-03-01

    The in vivo localization and speciation of lead (Pb) in tissues of the accumulator Sedum alfredii grown in EDTA-Pb and Pb(NO(3))(2) was studied by synchrotron X-ray investigation. The presence of EDTA-Pb in solution resulted in a significant reduction of Pb accumulation in S. alfredii. Lead was preferentially localized in the vascular bundles regardless of treatments but the intensities of Pb were lower in the plants treated with EDTA. Lead was predominantly presented as a Pb-cell wall complex in the plants regardless of its supply form. However, a relatively high proportion of Pb was observed as Pb-EDTA complex when the plant was treated with EDTA-Pb, but as a mixture of Pb(3)(PO(4))(2), Pb-malic, and Pb-GSH when cultured with ionic Pb. These results suggest that EDTA does not increase the internal mobility of Pb, although the soluble Pb-EDTA complex could be transported and accumulated within the plants of S. alfredii.

  13. The determination of major and some minor constituents in lead zirconate-titanate compositions by x-ray fluorescence and atomic absorption spectrometry

    NARCIS (Netherlands)

    Willigen, van J.H.H.G.; Kruidhof, H.; Dahmen, E.A.M.F.

    1972-01-01

    An accurate X-ray fluorescence spectrometric method is described for the determination of lead, zirconium and titanium in lead zirconate-titanate ceramics. Careful matching of samples and standards by a borax fusion method resulted in a relative standard deviation of about 0.2% for the major constit

  14. Skull x-ray

    Science.gov (United States)

    X-ray - head; X-ray - skull; Skull radiography; Head x-ray ... There is low radiation exposure. X-rays are monitored and regulated to provide the minimum amount of radiation exposure needed to produce the image. Most ...

  15. Neck x-ray

    Science.gov (United States)

    X-ray - neck; Cervical spine x-ray; Lateral neck x-ray ... There is low radiation exposure. X-rays are monitored so that the lowest amount of radiation is used to produce the image. Pregnant women and ...

  16. Determining copper and lead binding in Larrea tridentata through chemical modification and X-ray absorption spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Polette, L.; Gardea-Torresdey, J.L.; Chianelli, R. [Univ. of Texas, El Paso, TX (United States). Dept. of Chemistry; Pickering, I.J.; George, G.N. [Stanford Synchrotron Radiation Lab., Menlo Park, CA (United States)

    1997-12-31

    Metal contamination in soils has become a widespread problem. Emerging technologies, such as phytoremediation, may offer low cost cleanup methods. The authors have identified a desert plant, Larrea tridentata (creosote bush), which naturally grows and uptakes copper and lead from a contaminated area near a smelting operation. They determined, through chemical modification of carboxyl groups with methanol, that these functional groups may be responsible for a portion of copper(II) binding. In contrast, lead binding was minimally affected by modification of carboxyl groups. X-ray absorption spectroscopy studies conducted at Stanford Synchrotron Radiation Laboratory (SSRL) further support copper binding to oxygen-coordinated ligands and also imply that the binding is not solely due to phytochelatins. The EXAFS data indicate the presence of both Cu-O and Cu-S back scatters, no short Cu-Cu interactions, but with significant Cu-Cu back scattering at 3.7 {angstrom} (unlike phytochelatins with predominantly Cu-S coordination and short Cu-Cu interactions at 2.7 {angstrom}). Cu EXAFS of roots and leaves also vary depending on the level of heavy metal contamination in the environment from which the various creosote samples were obtained. In contrast, Pb XANES data of roots and leaves of creosote collected from different contaminated sites indicate no difference in valence states or ligand coordination.

  17. The impact of EDTA on lead distribution and speciation in the accumulator Sedum alfredii by synchrotron X-ray investigation

    Energy Technology Data Exchange (ETDEWEB)

    Tian Shengke [MOE Key Laboratory of Environment Remediation and Ecological Health, College of Environmental and Resource Science, Zhejiang University, Hangzhou 310029 (China); Lu Lingli, E-mail: linglilulu@gmail.com [MOE Key Laboratory of Environment Remediation and Ecological Health, College of Environmental and Resource Science, Zhejiang University, Hangzhou 310029 (China); Yang Xiaoe, E-mail: xyang571@yahoo.com [MOE Key Laboratory of Environment Remediation and Ecological Health, College of Environmental and Resource Science, Zhejiang University, Hangzhou 310029 (China); Huang Huagang [MOE Key Laboratory of Environment Remediation and Ecological Health, College of Environmental and Resource Science, Zhejiang University, Hangzhou 310029 (China); Brown, Patrick; Labavitch, John [Department of Plant Sciences, University of California, Davis, CA 95616 (United States); Liao Haibing [MOE Key Laboratory of Environment Remediation and Ecological Health, College of Environmental and Resource Science, Zhejiang University, Hangzhou 310029 (China); He Zhenli [University of Florida, Institute of Food and Agricultural Sciences, Indian River Research and Education Center, Fort Pierce, FL 34945 (United States)

    2011-03-15

    The in vivo localization and speciation of lead (Pb) in tissues of the accumulator Sedum alfredii grown in EDTA-Pb and Pb(NO{sub 3}){sub 2} was studied by synchrotron X-ray investigation. The presence of EDTA-Pb in solution resulted in a significant reduction of Pb accumulation in S. alfredii. Lead was preferentially localized in the vascular bundles regardless of treatments but the intensities of Pb were lower in the plants treated with EDTA. Lead was predominantly presented as a Pb-cell wall complex in the plants regardless of its supply form. However, a relatively high proportion of Pb was observed as Pb-EDTA complex when the plant was treated with EDTA-Pb, but as a mixture of Pb{sub 3}(PO{sub 4}){sub 2}, Pb-malic, and Pb-GSH when cultured with ionic Pb. These results suggest that EDTA does not increase the internal mobility of Pb, although the soluble Pb-EDTA complex could be transported and accumulated within the plants of S. alfredii. - Research highlights: > The plants of S. alfredii are less effective in taking up Pb from the EDTA-Pb medium. > Pb is mainly localized in the vascular bundles and probably as Pb-cell wall complex. > EDTA does not increase the internal mobility of Pb within the plants of S. alfredii. > The Pb-EDTA complex could be transported and accumulated within the plants. - The plants of S. alfredii are able to transport and accumulate the Pb-EDTA complex, but are less effective in taking up Pb from the EDTA-Pb medium.

  18. Determination of heavy metals concentrations in airborne particulates matter (APM) from Manjung district, Perak using energy dispersive X-ray fluorescence (EDXRF) spectrometer

    Science.gov (United States)

    Arshad, Nursyairah; Hamzah, Zaini; Wood, Ab. Khalik; Saat, Ahmad; Alias, Masitah

    2015-04-01

    Airborne particulates trace metals are considered as public health concern as it can enter human lungs through respiratory system. Generally, any substance that has been introduced to the atmosphere that can cause severe effects to living things and the environment is considered air pollution. Manjung, Perak is one of the development districts that is active with industrial activities. There are many industrial activities surrounding Manjung District area such as coal fired power plant, quarries and iron smelting which may contribute to the air pollution into the environment. This study was done to measure the concentrations of Hg, U, Th, K, Cu, Fe, Cr, Zn, As, Se, Pb and Cd in the Airborne Particulate Matter (APM) collected at nine locations in Manjung District area within 15 km radius towards three directions (North, North-East and South-East) in 5 km intervals. The samples were collected using mini volume air sampler with cellulose filter through total suspended particulate (TSP). The sampler was set up for eight hours with the flow rate of 5 L/min. The filter was weighed before and after sample collection using microbalance, to get the amount of APM and kept in desiccator before analyzing. The measurement was done using calibrated Energy Dispersive X-Ray Fluorescence (EDXRF) Spectrometer. The air particulate concentrations were found below the Malaysia Air Quality Guidelines for TSP (260 µg/m3). All of the metals concentrations were also lower than the guidelines set by World Health Organization (WHO), Ontario Ministry of the Environment and Argonne National Laboratory, USA NCRP (1975). From the concentrations, the enrichment factor were calculated.

  19. [Shielding effect of clinical X-ray protector and lead glass against annihilation radiation and gamma rays of 99mTc].

    Science.gov (United States)

    Fukuda, Atsushi; Koshida, Kichiro; Yamaguchi, Ichiro; Takahashi, Masaaki; Kitabayashi, Keitarou; Matsubara, Kousuke; Noto, Kimiya; Kawabata, Chikako; Nakagawa, Hiroto

    2004-12-01

    Various pharmaceutical companies in Japan are making radioactive drugs available for positron emission tomography (PET) in hospitals without a cyclotron. With the distribution of these drugs to hospitals, medical check-ups and examinations using PET are expected to increase. However, the safety guidelines for radiation in the new deployment of PET have not been adequately improved. Therefore, we measured the shielding effect of a clinical X-ray protector and lead glass against annihilation radiation and gamma rays of (99m)Tc. We then calculated the shielding effect of a 0.25 mm lead protector, 1 mm lead, and lead glass using the EGS4 (Electron Gamma Shower Version 4) code. The shielding effects of 22-mm lead glass against annihilation radiation and gamma rays of (99m)Tc were approximately 31.5% and 93.3%, respectively. The clinical X-ray protector against annihilation radiation approximately doubled the skin-absorbed dose.

  20. Chest X Ray?

    Science.gov (United States)

    ... this page from the NHLBI on Twitter. Chest X Ray A chest x ray is a fast and painless imaging test ... tissue scarring, called fibrosis. Doctors may use chest x rays to see how well certain treatments are ...

  1. 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 ... different amounts of radiation. Calcium in bones absorbs x-rays the most, so bones look white. Fat ...

  2. Medical X-Rays

    Science.gov (United States)

    ... Benefits The discovery of X-rays and the invention of CT represented major advances in medicine. X- ... in X-ray and CT Examinations — X-ray definition, dose measurement, safety precautions, risk, and consideration with ...

  3. Simple method of determination of copper, mercury and lead in potable water with preliminary pre-concentration by total reflection X-ray fluorescence spectrometry

    Science.gov (United States)

    Hołyńska, B.; Ostachowicz, B.; Wȩgrzynek, D.

    1996-06-01

    Total reflection X-ray fluorescence spectrometry and chemical pre-concentration procedures have been applied for the analysis of trace concentrations of copper, mercury, and lead in drinking water samples. A simple total reflection module has been used in X-ray measurements. The elements under investigation were pre-concentrated by complexation using a mixture of carbamates followed by solvent extraction with methyl isobutyl ketone. The preconcentration procedure was tested with the use of twice-distilled water samples and samples of mineral and tap water spiked with known additions of copper, mercury, and lead. The obtained recovery and precision values are presented. The minimum detection limits for the determination of these elements in mineral and tap water samples were found to be 40 ng l -1, 60 ng l -1, and 60 ng l -1, respectively.

  4. Assessment of Personal Airborne Exposures and Surface Contamination from X-ray Vaporization of Beryllium Targets at the National Ignition Facility.

    Science.gov (United States)

    Paik, Samuel Y; Epperson, Patrick M; Kasper, Kenneth M

    2017-02-28

    This study presents air and surface sampling data collected over the first two years since beryllium was introduced as a target material at the National Ignition Facility. Over this time, 101 experiments with beryllium-containing targets were executed. The data provides an assessment of current conditions in the facility and a baseline for future impacts as new, reduced regulatory limits for beryllium are being proposed by both the Occupational Safety and Health Administration and Department of Energy. This study also investigates how beryllium deposits onto exposed surfaces as a result of x-ray vaporization and the effectiveness of simple decontamination measures in reducing the amount of removable beryllium from a surface. Based on 1,961 surface wipe samples collected from entrant components (equipment directly exposed to target debris) and their surrounding work areas during routine reconfiguration activities, only one result was above the beryllium release limit of 0.2 μg/100 cm(2) and 27 results were above the analytical reporting limit of 0.01 μg/100 cm(2), for a beryllium detection rate of 1.4%. Surface wipe samples collected from the internal walls of the NIF target chamber, however, showed higher levels of beryllium, with beryllium detected on 73% and 87% of the samples during the first and second target chamber entries (performed annually), respectively, with 23% of the samples above the beryllium release limit during the second target chamber entry. The analysis of a target chamber wall panel exposed during the first 30 beryllium-containing experiments (cumulatively) indicated that 87% of the beryllium contamination remains fixed onto the surface after wet wiping the surface and 92% of the non-fixed contamination was removed by decontaminating the surface using a dry wipe followed by a wet wipe. Personal airborne exposures assessed during access to entrant components and during target chamber entry indicated that airborne beryllium was not present

  5. In Situ Solid-State Reactions Monitored by X-ray Absorption Spectroscopy: Temperature-Induced Proton Transfer Leads to Chemical Shifts.

    Science.gov (United States)

    Stevens, Joanna S; Walczak, Monika; Jaye, Cherno; Fischer, Daniel A

    2016-10-24

    The dramatic colour and phase alteration with the solid-state, temperature-dependent reaction between squaric acid and 4,4'-bipyridine has been probed in situ with X-ray absorption spectroscopy. The electronic and chemical sensitivity to the local atomic environment through chemical shifts in the near-edge X-ray absorption fine structure (NEXAFS) revealed proton transfer from the acid to the bipyridine base through the change in nitrogen protonation state in the high-temperature form. Direct detection of proton transfer coupled with structural analysis elucidates the nature of the solid-state process, with intermolecular proton transfer occurring along an acid-base chain followed by a domino effect to the subsequent acid-base chains, leading to the rapid migration along the length of the crystal. NEXAFS thereby conveys the ability to monitor the nature of solid-state chemical reactions in situ, without the need for a priori information or long-range order.

  6. X-Ray Astronomy

    Science.gov (United States)

    Wu, S. T.

    2000-01-01

    Dr. S. N. Zhang has lead a seven member group (Dr. Yuxin Feng, Mr. XuejunSun, Mr. Yongzhong Chen, Mr. Jun Lin, Mr. Yangsen Yao, and Ms. Xiaoling Zhang). This group has carried out the following activities: continued data analysis from space astrophysical missions CGRO, RXTE, ASCA and Chandra. Significant scientific results have been produced as results of their work. They discovered the three-layered accretion disk structure around black holes in X-ray binaries; their paper on this discovery is to appear in the prestigious Science magazine. They have also developed a new method for energy spectral analysis of black hole X-ray binaries; four papers on this topics were presented at the most recent Atlanta AAS meeting. They have also carried Monte-Carlo simulations of X-ray detectors, in support to the hardware development efforts at Marshall Space Flight Center (MSFC). These computation-intensive simulations have been carried out entirely on the computers at UAH. They have also carried out extensive simulations for astrophysical applications, taking advantage of the Monte-Carlo simulation codes developed previously at MSFC and further improved at UAH for detector simulations. One refereed paper and one contribution to conference proceedings have been resulted from this effort.

  7. X-ray Absorption Spectroscopy of Zinc in Airborne Particulate Matter Shows Tire Debris Concentrated in > 0.5 μm Fraction

    Science.gov (United States)

    Pingitore, N. E.; Clague, J. W.; Gill, T. E.; Amaya, M. A.; Cahill, T. A.

    2009-12-01

    Using X-ray absorption spectroscopy (XAS), we speciated Zn in size-resolved fractions of particulate matter (PM) from El Paso, Texas. Spectral patterns indicated that Zn in tire debris is the dominant form of Zn in PM coarser than 0.5 μm in aerodynamic diameter. Although concentrated in the > 0.5 μm fraction, a large portion of the tire debris in PM is small enough to penetrate and deposit in the lower respiratory tract. We collected 3 sets of size-resolved samples of airborne particulate matter (PM) over periods of several days to several weeks in November 2008, and April and May 2009. Local PM compositions typically are dominated by anthropogenic input in November and geologic sources in April, and a mixture in May. The collection site is in the urban core of El Paso, TX, contiguous to the University of Texas at El Paso, 0.6 km from Interstate Highway 10, 0.4 km from State Highway 20, and 1 km from Cd. Juarez, Chihuahua, Mexico. The DRUM sampler (Davis Rotating Uniform size-cut Monitor) employs a rotating Lundgren-type impactor, draws 10 l per minute, and deposits PM on plastic strips mounted on rotating drums. The sampler collected and segregated ambient PM into 8 size cuts: 12-5 μm, 5-2.5, 2.5-1.15, 1.15-0.75, 0.75-0.56, 0.56-0.34, 0.34-0.26, and 0.26-0.09. We conducted the X-ray absorption spectroscopy (XAS) experiments at the Stanford Synchrotron Radiation Lightsource on beam line 7-3. Spectra of the 24 samples of PM and numerous model compounds were collected at the Zn K absorption edge in fluorescence mode using a 30-element Ge solid-state detector. The overall spectral patterns from the 3 seasons were similar to one another. But strikingly, each set of 8 XAS spectra displayed an obvious change in the Zn speciation at the 0.56-0.75 μm size cut. We compared the PM spectra to those of our suite of known model compounds and materials. The spectral pattern of the coarser size cuts was quite similar to those of the tires we tested. The Zn in the tires

  8. Monitoring the Phase Formation of Coevaporated Lead Halide Perovskite Thin Films by in Situ X-ray Diffraction.

    Science.gov (United States)

    Pistor, Paul; Borchert, Juliane; Fränzel, Wolfgang; Csuk, René; Scheer, Roland

    2014-10-02

    Perovskite solar cells based on (CH3NH3)Pb(I,Cl)3 have recently demonstrated rapidly increasing cell efficiencies. Here, we show progress identifying phases present during the growth of (CH3NH3)Pb(I,Cl)3 perovskite thin films with the vacuum-based coevaporation approach using two sources under varying deposition conditions. With in situ X-ray diffraction, crystalline phases can be identified and monitored in real time. For different (CH3NH3)I-to-PbCl2 flux ratios, two distinct (CH3NH3)Pb(IxCl(1-x))3 phases with high (x > 0.95) and with lower (x perovskite film to PbI2 at temperatures above 200 °C.

  9. Detection of lead in Zea mays by dual-energy X-ray microtomography at the SYRMEP beamline of the ELETTRA synchrotron and by atomic absorption spectroscopy.

    Science.gov (United States)

    Reale, Lucia; Kaiser, Jozef; Pace, Loretta; Lai, Antonia; Flora, Francesco; Angelosante Bruno, Antonella; Tucci, Adele; Zuppella, Paola; Mancini, Lucia; Tromba, Giuliana; Ruggieri, Fabrizio; Fanelli, Maria; Malina, Radomir; Liska, Miroslav; Poma, Anna

    2010-06-01

    This study is related to the application of the X-ray dual-energy microradiography technique together with the atomic absorption spectroscopy (AAS) for the detection of lead on Zea mays stem, ear, root, and leaf samples. To highlight the places with lead intake, the planar radiographs taken with monochromatic X-ray radiation in absorption regime with photon energy below and above the absorption edge of a given chemical element, respectively, are analyzed and processed. To recognize the biological structures involved in the intake, the dual-energy images with the lead signal have been compared with the optical images of the same Z. mays stem. The ear, stem, root, and leaf samples have also been analyzed with the AAS technique to measure the exact amount of the hyperaccumulated lead. The AAS measurement revealed that the highest intake occurred in the roots while the lowest in the maize ears and in the leaf. It seems there is a particular mechanism that protects the seeds and the leaves in the intake process.

  10. Abdominal x-ray

    Science.gov (United States)

    ... are, or may be, pregnant. Alternative Names Abdominal film; X-ray - abdomen; Flat plate; KUB x-ray ... Assistant Studies, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington, Seattle, WA. Also ...

  11. Extremity x-ray

    Science.gov (United States)

    ... degenerative) Bone tumor Broken bone (fracture) Dislocated bone Osteomyelitis (infection) Arthritis Other conditions for which the test ... Bone tumor Bone x-ray Broken bone Clubfoot Osteomyelitis X-ray Review Date 7/3/2016 Updated ...

  12. Absolute L-shell ionization and X-ray production cross sections of Lead and Thorium by 16-45 keV electron impact

    CERN Document Server

    Rahangdale, H V; De, S; Santos, J P; Mitra, D; Guerra, M; Saha, S

    2015-01-01

    The absolute L subshell specific electron impact ionization cross sections near the ionization threshold (16 < E < 45 keV) of Lead and Thorium are obtained from the measured L X-ray production cross sections. Monte Carlo simulation is done to account for the effect of the backscattered electrons and the final experimental results are compared with calculations performed using distorted wave Born approximation and the modified relativistic binary encounter Bethe model.The sensitivity of the results on the atomic parameters is explored. Observed agreements and discrepancies between the experimental results and theoretical estimates, and their dependence on the specific atomic parameters are reported.

  13. X-Ray Supernovae

    CERN Document Server

    Immler, S; Immler, Stefan; Lewin, Walter H.G.

    2002-01-01

    We present a review of X-ray observations of supernovae (SNe). By observing the (~0.1--100 keV) X-ray emission from young SNe, physical key parameters such as the circumstellar matter (CSM) density, mass-loss rate of the progenitor and temperature of the outgoing and reverse shock can be derived as a function of time. Despite intensive search over the last ~25 years, only 15 SNe have been detected in X-rays. We review the individual X-ray observations of these SNe and discuss their implications as to our understanding of the physical processes giving rise to the X-ray emission.

  14. Experimental demonstration of benchtop x-ray fluorescence computed tomography (XFCT) of gold nanoparticle-loaded objects using lead- and tin-filtered polychromatic cone-beams.

    Science.gov (United States)

    Jones, Bernard L; Manohar, Nivedh; Reynoso, Francisco; Karellas, Andrew; Cho, Sang Hyun

    2012-12-07

    This report presents the first experimental demonstration, to our knowledge, of benchtop polychromatic cone-beam x-ray fluorescence computed tomography (XFCT) for a simultaneous determination of the spatial distribution and amount of gold nanoparticles (GNPs) within small-animal-sized objects. The current benchtop experimental setup successfully produced XFCT images accurately showing the regions containing small amount of GNPs (on the order of 0.1 mg) within a 3 cm diameter plastic phantom. In particular, the performance of the current XFCT setup was improved remarkably (e.g., at least a factor of 3 reduction in XFCT scan time) using a tin-filtered polychromatic beam in comparison with a lead-filtered beam. The results of this study strongly suggest that the current benchtop XFCT configuration can be made practical with a few modifications such as the deployment of array detectors, while meeting realistic constraints on x-ray dose, scan time and image resolution for routine pre-clinical in vivo imaging with GNPs.

  15. X-Ray Polarimetry

    CERN Document Server

    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 soft X-ray polarimeters based on Bragg reflection. Developments in scintillator and solid-state hard X-ray detectors facilitate construction of both modular, large area Compton scattering polarimeters and compact devices suitable for use with focusing X-ray telescopes.

  16. Studies of cadmium, mercury and lead in man. The value of X-ray fluorescence measurements in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Boerjesson, J.

    1996-10-01

    Two XRF methods have been used for in vivo studies of mercury, cadmium and lead. Persons with a history of long-term occupational mercury exposure had elevated mercury concentrations in their kidneys (up to 65 {mu}g/g). The minimum detectable concentration varied between 12 and 45 {mu}g/g. Battery plant workers had elevated cadmium concentrations in their kidneys (up to 350 {mu}g/g) and liver (up to 80 {mu}g/g), with mean values about 3-5 times higher than the general population. The mean ratio between concentrations of cadmium in kidney and liver was 7. Levels in kidney and liver indicated that a simple integration of cadmium in work-place air is not sufficient to describe the body burden. Fingerbone lead in smelters was 6-8 times higher than in members of the general population. The half-time of bone lead in active workers was estimated to about 5 years during the accumulation phase. A model for description of a person`s lead exposure in terms of lead in fingerbone, lead in blood and time of exposure has been developed and can be used, e.g. for retrospective blood lead estimates if the period of exposure and the current fingerbone lead is known. This will be of value for the evaluation of toxic effects of long-term lead exposure when data on previous lead levels are lacking. In total, in vivo measurements of mercury, cadmium and lead give unique information, which has shown to be an important tool for understanding of metal kinetics and toxicity. If the precision and accuracy of the method can be further improved, the technique will also have a given place in the clinical practice. 168 refs, 9 figs, 3 tabs

  17. Study of interaction of iron and lead during their uptake process in wheat roots by total-reflection X-ray fluorescence spectrometry

    Science.gov (United States)

    Varga, Anita; Záray, Gyula; Fodor, Ferenc; Cseh, Edit

    1997-07-01

    Microwave assisted acidic digestion and total-reflection X-ray fluorescence spectrometry (TXRF) was used for the determination of lead and iron in wheat roots cultured in CaSO 4 solution, and treated with Pb(NO 3) 2 and Fe(III)-citrate or Fe(III)-EDTA under controlled conditions, respectively. It was established that lead has a stimulation effect on the iron uptake in the presence of Fe(III)-citrate. The lead uptake, however, is hardly influenced by iron independently from the complex forming agents applied. To check the stability of the accumulated iron and lead constituents, some of the roots were washed with various solutions and the removable iron and lead were also measured by TXRF. These experiments indicate that the presence of lead results in higher stability of iron constituents in the root; however, iron does not have any effect on the lead constituents, the stabilities of which increase in the order Pb-citrate

  18. Dental x-rays

    Science.gov (United States)

    ... X-rays are a form of high energy electromagnetic radiation. The x-rays penetrate the body to form ... for detecting cavities, unless the decay is very advanced and deep. Many ... The amount of radiation given off during the procedure is less than ...

  19. X-ray pulsar rush in 1998

    Energy Technology Data Exchange (ETDEWEB)

    Imanishi, K.; Tsujimoto, K.; Nishiuchi, Mamiko; Yokogawa, J.; Koyama, K. [Kyoto Univ., Faculty of Science, Kyoto (Japan)

    1999-08-01

    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 {approx} 10{sup 15} 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)

  20. X-Ray Surveys

    CERN Document Server

    Giommi, P; Perri, M

    1998-01-01

    A review of recent developments in the field of X-ray surveys, especially in the hard (2-10 and 5-10 keV) bands, is given. A new detailed comparison between the measurements in the hard band and extrapolations from ROSAT counts, that takes into proper account the observed distribution of spectral slopes, is presented. Direct comparisons between deep ROSAT and BeppoSAX images show that most hard X-ray sources are also detected at soft X-ray energies. This may indicate that heavily cutoff sources, that should not be detectable in the ROSAT band but are expected in large numbers from unified AGN schemes, are in fact detected because of the emerging of either non-nuclear components, or of reflected, or partially transmitted nuclear X-rays. These soft components may complicate the estimation of the soft X-ray luminosity function and cosmological evolution of AGN.

  1. Relationship between soil lead and airborne lead concentrations at Springfield, Missouri, USA

    Energy Technology Data Exchange (ETDEWEB)

    Sheets, R.W.; Kyger, J.R.; Biagioni, R.N.; Probst, S. [Department of Chemistry, Southwest Missouri State University, 65804 Springfield, MO (United States); Boyer, R.; Barke, K. [Greene County Health Department, 65802 Springfield, MO (United States)

    2001-04-23

    This study tests whether lead deposited to soil from automobiles during past years in a medium-sized US city (population 150000) may present a current health risk. It examines the relationship between current soil lead concentrations at nine locations within the city of Springfield, Missouri, and airborne lead levels measured at the same locations during years (1975-1981) when lead emissions from automobiles were much greater than at present. A strong, significant correlation is found between soil and airborne lead levels at eight of the sites (r=0.91, P<0.005 for soil lead vs. 1979 airborne lead), in low-traffic areas as well as in areas adjacent to heavy traffic flow. Residual lead concentrations in these soils are relatively low, even for the high-traffic sites, as expected for a medium sized city.

  2. Degradation process of lead chromate in paintings by Vincent van Gogh studied by means of synchrotron X-ray spectromicroscopy and related methods. 2. Original paint layer samples.

    Science.gov (United States)

    Monico, Letizia; Van der Snickt, Geert; Janssens, Koen; De Nolf, Wout; Miliani, Costanza; Dik, Joris; Radepont, Marie; Hendriks, Ella; Geldof, Muriel; Cotte, Marine

    2011-02-15

    The darkening of the original yellow areas painted with the chrome yellow pigment (PbCrO(4), PbCrO(4)·xPbSO(4), or PbCrO(4)·xPbO) is a phenomenon widely observed on several paintings by Vincent van Gogh, such as the famous different versions of Sunflowers. During our previous investigations on artificially aged model samples of lead chromate, we established for the first time that darkening of chrome yellow is caused by reduction of PbCrO(4) to Cr(2)O(3)·2H(2)O (viridian green), likely accompanied by the presence of another Cr(III) compound, such as either Cr(2)(SO(4))(3)·H(2)O or (CH(3)CO(2))(7)Cr(3)(OH)(2) [chromium(III) acetate hydroxide]. In the second part of this work, in order to demonstrate that this reduction phenomenon effectively takes place in real paintings, we study original paint samples from two paintings of V. van Gogh. As with the model samples, in view of the thin superficial alteration layers that are present, high lateral resolution spectroscopic methods that make use of synchrotron radiation (SR), such as microscopic X-ray absorption near edge (μ-XANES) and X-ray fluorescence spectrometry (μ-XRF) were employed. Additionally, μ-Raman and mid-FTIR analyses were carried out to completely characterize the samples. On both paint microsamples, the local presence of reduced Cr was demonstrated by means of μ-XANES point measurements. The presence of Cr(III) was revealed in specific areas, in some cases correlated to the presence of Ba(sulfate) and/or to that of aluminum silicate compounds.

  3. Comparison of direct (X-ray diffraction and infrared spectrophotometry) and indirect (infrared spectrophotometry) methods for the analysis of alpha-quartz in airborne dusts.

    Science.gov (United States)

    Kauffer, E; Masson, A; Moulut, J C; Lecaque, T; Protois, J C

    2005-11-01

    In this study, the alpha-quartz contents measured by different analytical techniques (X-ray diffraction, direct method; and infrared spectrophotometry, direct and indirect methods) were compared. The analyses were carried out on filters sampled in an industrial setting by means of a Dorr-Oliver cyclone. To verify the methodology used, filters loaded with pure alpha-quartz were also analysed. By and large, the agreement between the two direct methods was close on average, but on the basis of a comparison of the individual results, considerable differences exist. In absolute value, the mean relative deviation between the two techniques was infrared) were on average 13% lower than the results obtained by the two direct methods with a more important difference (23%) for samples where calcite was identified by X-ray diffraction in comparison with those where it was not (8%). This underestimation, which was not owing to dust losses during preparation, is probably explained by the elimination of organic compounds during dust calcinations or by the transformation of mineral compounds. The indirect method introduces additional sample handling operations with more risk of material loss. When the quantity of calcined material was <0.4 mg, the weighing operations necessary to correct any losses of material resulted in considerable variability. In terms of overall uncertainty, it would be better in this case not to carry out correction and to employ an operating mode favouring the recovery of a maximum of material while accepting a bias of about 5-7%.

  4. 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.

  5. Determination of Thermal Expansion Coefficients and Locating the Temperature-Induced Phase Transition in Methylammonium Lead Perovskites Using X-ray Diffraction.

    Science.gov (United States)

    Jacobsson, T Jesper; Schwan, L Josef; Ottosson, Mikael; Hagfeldt, Anders; Edvinsson, Tomas

    2015-11-16

    Lead halogen perovskites, and particularly methylammonium lead iodine, CH3NH3PbI3, have recently attracted considerable interest as alternative solar cell materials, and record solar cell efficiencies have now surpassed 20%. Concerns have, however, been raised about the thermal stability of methylammonium lead iodine, and a phase transformation from a tetragonal to a cubic phase has been reported at elevated temperature. Here, this phase transition has been investigated in detail using temperature-dependent X-ray diffraction measurements. The phase transformation is pinpointed to 54 °C, which is well within the normal operating range of a typical solar cell. The cell parameters were extracted as a function of the temperature, from which the thermal expansion coefficient was calculated. The latter was found to be rather high (αv = 1.57 × 10(-4) K(-1)) for both the tetragonal and cubic phases. This is 6 times higher than the thermal expansion coefficient for soda lime glass and CIGS and 11 times larger than that of CdTe. This could potentially be of importance for the mechanical stability of perovskite solar cells in the temperature cycling experienced under normal day-night operation. The experimental knowledge of the thermal expansion coefficients and precise determination of the cell parameters can potentially also be valuable while conducting density functional theory simulations on these systems in order to deliver more accurate band structure calculations.

  6. 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

  7. Determination of lead in clay enameled by X-ray fluorescence technique in Total reflection and by Scanning Electron Microscopy; Determinacion de plomo en esmaltado de barro por Fluorescencia de rayos X en reflexion total y Microscopia Electronica de Barrido

    Energy Technology Data Exchange (ETDEWEB)

    Zarazua O, G.; Carapia M, L. [Instituto Nacional de Investigaciones Nucleares, C.P. 52045 Estado de Mexico (Mexico)

    2000-07-01

    This work has the objective of determining lead free in the glazed commercial stewing pans using the X-ray fluorescence technique in Total reflection (FRX) and the observation and semiquantitative determination of lead by Analytical Scanning Electron Microscopy (ASEM). (Author)

  8. 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)

  9. Pelvis x-ray

    Science.gov (United States)

    X-ray - pelvis ... Tumors Degenerative conditions of bones in the hips, pelvis, and upper legs ... hip joint Tumors of the bones of the pelvis Sacroiliitis (inflammation of the area where the sacrum ...

  10. X-ray - skeleton

    Science.gov (United States)

    ... x-ray particles pass through the body. A computer or special film records the images. Structures that ... M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health ...

  11. Bone x-ray

    Science.gov (United States)

    ... or broken bone Bone tumors Degenerative bone conditions Osteomyelitis (inflammation of the bone caused by an infection) ... Multiple myeloma Osgood-Schlatter disease Osteogenesis imperfecta Osteomalacia Osteomyelitis Paget disease of the bone Rickets X-ray ...

  12. Hand x-ray

    Science.gov (United States)

    ... include fractures, bone tumors , degenerative bone conditions, and osteomyelitis (inflammation of the bone caused by an infection). ... chap 46. Read More Bone tumor Broken bone Osteomyelitis X-ray Review Date 9/8/2014 Updated ...

  13. Chest X-Ray

    Medline Plus

    Full Text Available ... breath, persistent cough, fever, chest pain or injury. It may also be useful to help diagnose and ... have some concerns about chest x-rays. However, it’s important to consider the likelihood of benefit to ...

  14. Short chain lead (II) alkanoates as ionic liquids and glass formers: A d.s.c., X-ray diffraction and FTIR spectroscopy study

    Energy Technology Data Exchange (ETDEWEB)

    Martinez Casado, F.J. [Departamento de Quimica Fisica, Facultad de Ciencias Quimicas, Universidad Complutense, 28040 Madrid (Spain); Sanchez Arenas, A. [Seccion Departamental de Fisica Aplicada I, Facultad de Veterinaria (Spain); Garcia Perez, M.V. [Departamento de Quimica Fisica, Facultad de Ciencias Quimicas, Universidad Complutense, 28040 Madrid (Spain); Redondo Yelamos, M.I. [Departamento de Quimica Fisica, Facultad de Ciencias Quimicas, Universidad Complutense, 28040 Madrid (Spain); Lopez de Andres, S. [Departamento de Cristalografia, Facultad de Ciencias Geologicas, Universidad Complutense, 28040 Madrid (Spain); Cheda, J.A.R. [Departamento de Quimica Fisica, Facultad de Ciencias Quimicas, Universidad Complutense, 28040 Madrid (Spain)]. E-mail: cheda@quim.ucm.es

    2007-03-15

    Three members of the lead (II) n-alkanoates (from etanoate to n-butanoate) have been synthesized, purified and studied by d.s.c., X-ray diffraction, and FTIR spectroscopy. Lead (II) acetate, propanoate, and butanoate present only a melting transition at T = (452.6, 398.2, and 346.5) K, with {delta}{sub f} H = (16.0, 13.1, and 15.6) kJ . mol{sup -1}, and {delta}{sub f} S (35.3, 32.8, and 45.1) J . mol{sup -1} . K{sup -1}, respectively. These temperature data correct to a great extent the historical values reported in the literature. These three members readily quench into a glass state. Their corresponding T {sub g} values are (314.4, 289.0, and 274.9) K, respectively, measured by d.s.c. at a heating rate of 5 K . min{sup -1}.

  15. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... that might interfere with the x-ray images. Women should always inform their physician and x-ray ... Safety page for more information about radiation dose. Women should always inform their physician or x-ray ...

  16. 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 ...

  17. Identification of sources of lead in the atmosphere by chemical speciation using X-ray absorption near-edge structure (XANES) spectroscopy.

    Science.gov (United States)

    Sakata, Kohei; Sakaguchi, Aya; Tanimizu, Masaharu; Takaku, Yuichi; Yokoyama, Yuka; Takahashi, Yoshio

    2014-02-01

    Sources of Pb pollution in the local atmosphere together with Pb species, major ions, and heavy metal concentrations in a size-fractionated aerosol sample from Higashi-Hiroshima (Japan) have been determined by X-ray absorption near-edge structure (XANES) spectroscopy, ion chromatography, and ICP-MS/AES, respectively. About 80% of total Pb was concentrated in fine aerosol particles. Lead species in the coarse aerosol particles were PbC2O4, 2PbCO3 Pb(OH)2, and Pb(NO3)2, whereas Pb species in the fine aerosol particles were PbC2O4, PbSO4, and Pb(NO3)2. Chemical speciation and abundance data suggested that the source of Pb in the fine aerosol particles was different from that of the coarse ones. The dominant sources of Pb in the fine aerosol particles were judged to be fly ash from a municipal solid waste incinerator and heavy oil combustion. For the coarse aerosol particles, road dust was considered to be the main Pb source. In addition to Pb species, elemental concentrations in the aerosols were also determined. The results suggested that Pb species in size-fractionated aerosols can be used to identify the origin of aerosol particles in the atmosphere as an alternative to Pb isotope ratio measurement.

  18. Factors influencing uncertainties of in vivo bone lead measurement using a (109)Cd K X-ray fluorescence clover leaf geometry detector system.

    Science.gov (United States)

    Behinaein, Sepideh; Chettle, David R; Marro, Leonora; Malowany, Morie; Fisher, Mandy; Fleming, David E B; Healey, Norm; Inskip, Mike; Arbuckle, Tye E; McNeill, Fiona E

    2014-12-01

    A (109)Cd K X-ray fluorescence (KXRF) measurement system consisting of four detectors in clover-leaf geometry is a non-invasive, low-radiation-dose method of measuring bone lead concentration. Its high precision in estimating the bone lead content makes it a promising tool for the determination of the low levels of lead currently found in the general population. After developing the clover-leaf geometry system, the system was used for the first time in a major survey in 2008 to measure the lead levels of 497 smelter employees (an occupationally exposed group with high lead levels). Since the delivered effective dose of the bone lead system in clover-leaf geometry is small (on the order of nSv), the technique can be used to measure the bone lead of sensitive populations such as the elderly and children. This detector system was used from 2009 to 2011, in a pilot study that measured the bone lead concentration of 263 environmentally exposed individuals (termed the EG group) residing in Toronto, Ontario, Canada. In this paper, the factors that influence uncertainties in lead content in tibia (cortical bone) and calcaneus (trabecular bone) are discussed based on gender, age, and body mass index (BMI) by using analysis of variance (ANOVA) and multiple linear regression models. Results from the two study groups (the EG group versus the occupationally exposed smelter employees) are compared where appropriate (i.e. for males older than 20). Results from univariate analyses showed that females have higher tibia uncertainty compared to males. We observed significant differences for both calcaneus and tibia uncertainty measures (p < 0.0005) among different age groups, where the uncertainties were highest in the lowest age group (<11 years). Lastly, and perhaps most significantly, we found that the product of source activity and measurement time influenced the precision of measurements greatly, and that this factor alone could account for the higher uncertainties observed for

  19. 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. ...

  20. A new anthropometric phantom of the human leg for calibrating in vivo measurements of stable lead in bone using x-ray fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Spitz, Henry; Jenkins, Mark; Lodwick, Jeffrey [Cincinnati Univ., OH (United States). Dept. of Mechanical, Industrial and Nuclear Engineering

    1997-12-31

    Full text. A new anthropometric phantom of the human leg has been developed for calibrating in vivo measurements of stable lead in the bone using x-ray fluorescence. The phantom reproduces the shape and radiological characteristics of the midshaft of the human leg and includes tissue substitutes for cortical bone, bone marrow, and muscle which have been formulated using polyurethanes and calcium carbonate to provide the desired characteristics of density x-ray attenuation, and calcium content. The phantom includes a set of simulated tibia bones, each containing a precisely known concentration of stable lead, that can be easily inserted into the leg. Formerly, of a set of plexiglas cylinders filled with plaster of-paris, each containing a known lead content, was the consensus standard calibration phantom. Tissue substitute materials used in the new anthropometric calibration phantom are much more uniform in density and composition than the plaster-of-paris phantoms and its realistic appearance provides a practical means of evaluating the variability in measurements results due to the changes in subject-detector positioning. Use of the new anthropometric calibration phantom results in a energy spectrum that closely resembles the spectrum observed when measuring a human subject. The energy spectrum produced by the plaster-of-paris phantom lacks the substantial Compton Scattering component produced by the leg muscle mass which leads to unrealistic estimates of in vivo measurement sensitivity. The minimum detection limit (MDL) for in vivo measurement of stable lead in bone, using an efficiency derived from the new anthropometric phantom, ranges from 18,6 parts per million (ppm) to 26,3 ppm using the K{sub {beta}1,3}/Elastic ratio or the K{sup 1}/Elastic ratio, respectively. These values are significantly greater than the MDL cited in the literature obtained using a efficiency derived the conventional cylindrical plaster-of-paris phantom. Likewise, the realistic shape of

  1. 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.

  2. A Burst Chasing X-ray Polarimeter

    Science.gov (United States)

    Hill, Joanne

    2007-01-01

    This viewgraph presentation reviews the rationale, design, and importance of an X-Ray Polarimeter. There is a brief discussion of Gamma Ray Bursts, followed by a review of the theories of Gamma-Ray Bursts Polarization. This leads to the question of "How do we measure the polarization?" and a discussion of the GRB x-ray emission, the photoelectric effect and photoelectric polarimetry. The requirements for the work, can only be approached using a gas detector. This leads to a discussion of a Micropattern Gas Polarimeter, and the Time-Projection Chamber (TPC) X-ray Polarimeter.

  3. 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...

  4. Tile concrete base materials as substitutes for lead shielding installations diagnostic X-ray; Losetas de materiales con base de hormigon como blindajes sustitutivos del plomo en instalaciones de rayos X de diagnostico

    Energy Technology Data Exchange (ETDEWEB)

    Pombar Camean, M.; Pasin, J.; Fuestes-Vazquez, V.; Alonso, E.; Pereira, B.

    2011-07-01

    In this paper we study the damping characteristics in the energy range of medical diagnostic X-ray product X-RAD trade name manufactured by Construction Radiotherapy Techniques (CTRADC) consisting of different composition tile with concrete base, for its characterization as a substitute shielding material lead.

  5. X-Ray Protection

    Science.gov (United States)

    1955-01-01

    15,000. • When developed In Kodak liquid X-ray developer for 5 min at a temperature of 200 C. b Film sensitivities vary with photon energy by the...for example temporomandibular -joint exposures where a skin dose of 25 r or more may be obtained during a single exposure with 65 kvp, 1.5 mm aluminum...communication. W. J. Updegrave, Temporomandibular articulation-X-ray examina- tion, Dental Radiography and Photography 26, No. 3, 41 (1953). H. 0. Wyckoff, R. J

  6. Determination of the feasibility of using a portable X-ray fluorescence (XRF) analyzer in the field for measurement of lead content of sieved soil.

    Science.gov (United States)

    Markey, Andrea M; Clark, C Scott; Succop, Paul A; Roda, Sandra

    2008-03-01

    Soil samples collected in housing areas with potential lead contamination generally are analyzed with flame atomic absorption spectrometry (FAAS) or other laboratory methods. Previous work indicates that field-portable X-ray fluorescence (XRF) analysis is capable of detecting soil lead levels comparable to those detected by FAAS in samples sieved to less than 125 microm in a laboratory. A considerable savings, both economical and in laboratory reporting time, would occur if a practical field method could be developed that does not require laboratory digestion and analysis. The XRF method also would provide immediate results that would facilitate the provision of information to residents and other interested parties more quickly than is possible with conventional laboratory methods. The goal of the study reported here was to determine the practicality of using the field-portable XRF analyzer for analysis of lead in soil samples that were sieved in the field. The practicality of using the XRF was determined by the amount of time it took to prepare and analyze the samples in the field and by the ease with which the procedure could be accomplished on site. Another objective of the study was to determine the effects of moisture on the process of sieving the soil. Seventy-eight samples were collected from 30 locations near 10 houses and were prepared and analyzed at the locations where they were collected. Mean soil lead concentrations by XRF were 816 ppm before drying and 817 ppm after drying, and by laboratory FAAS were 1,042 ppm. Correlation of field-portable XRF and FAAS results was excellent for samples sieved to less than 125 microm, with R2 values of .9902 and .992 before and after drying, respectively. The saturation ranged from 10 percent to 90 percent. At 65 percent saturation or higher, it was not feasible to sieve the soil in the field without a thorough drying step, since the soil would not pass through the sieve. Therefore the field method with sieving was

  7. 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.

  8. Experimental X-Ray Ghost Imaging

    Science.gov (United States)

    Pelliccia, Daniele; Rack, Alexander; Scheel, Mario; Cantelli, Valentina; Paganin, David M.

    2016-09-01

    We report an experimental proof of principle for ghost imaging in the hard-x-ray energy range. We use a synchrotron x-ray beam that is split using a thin crystal in Laue diffraction geometry. With an ultrafast imaging camera, we are 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 is correlated with the spatially resolved intensity measured in 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 nondestructive structural characterization using free electron lasers.

  9. Establishing nonlinearity thresholds with ultraintense X-ray pulses.

    Science.gov (United States)

    Szlachetko, Jakub; Hoszowska, Joanna; Dousse, Jean-Claude; Nachtegaal, Maarten; Błachucki, Wojciech; Kayser, Yves; Sà, Jacinto; Messerschmidt, Marc; Boutet, Sebastien; Williams, Garth J; David, Christian; Smolentsev, Grigory; van Bokhoven, Jeroen A; Patterson, Bruce D; Penfold, Thomas J; Knopp, Gregor; Pajek, Marek; Abela, Rafael; Milne, Christopher J

    2016-09-13

    X-ray techniques have evolved over decades to become highly refined tools for a broad range of investigations. Importantly, these approaches rely on X-ray measurements that depend linearly on the number of incident X-ray photons. The advent of X-ray free electron lasers (XFELs) is opening the ability to reach extremely high photon numbers within ultrashort X-ray pulse durations and is leading to a paradigm shift in our ability to explore nonlinear X-ray signals. However, the enormous increase in X-ray peak power is a double-edged sword with new and exciting methods being developed but at the same time well-established techniques proving unreliable. Consequently, accurate knowledge about the threshold for nonlinear X-ray signals is essential. Herein we report an X-ray spectroscopic study that reveals important details on the thresholds for nonlinear X-ray interactions. By varying both the incident X-ray intensity and photon energy, we establish the regimes at which the simplest nonlinear process, two-photon X-ray absorption (TPA), can be observed. From these measurements we can extract the probability of this process as a function of photon energy and confirm both the nature and sub-femtosecond lifetime of the virtual intermediate electronic state.

  10. Establishing nonlinearity thresholds with ultraintense X-ray pulses

    Science.gov (United States)

    Szlachetko, Jakub; Hoszowska, Joanna; Dousse, Jean-Claude; Nachtegaal, Maarten; Błachucki, Wojciech; Kayser, Yves; Sà, Jacinto; Messerschmidt, Marc; Boutet, Sebastien; Williams, Garth J.; David, Christian; Smolentsev, Grigory; van Bokhoven, Jeroen A.; Patterson, Bruce D.; Penfold, Thomas J.; Knopp, Gregor; Pajek, Marek; Abela, Rafael; Milne, Christopher J.

    2016-09-01

    X-ray techniques have evolved over decades to become highly refined tools for a broad range of investigations. Importantly, these approaches rely on X-ray measurements that depend linearly on the number of incident X-ray photons. The advent of X-ray free electron lasers (XFELs) is opening the ability to reach extremely high photon numbers within ultrashort X-ray pulse durations and is leading to a paradigm shift in our ability to explore nonlinear X-ray signals. However, the enormous increase in X-ray peak power is a double-edged sword with new and exciting methods being developed but at the same time well-established techniques proving unreliable. Consequently, accurate knowledge about the threshold for nonlinear X-ray signals is essential. Herein we report an X-ray spectroscopic study that reveals important details on the thresholds for nonlinear X-ray interactions. By varying both the incident X-ray intensity and photon energy, we establish the regimes at which the simplest nonlinear process, two-photon X-ray absorption (TPA), can be observed. From these measurements we can extract the probability of this process as a function of photon energy and confirm both the nature and sub-femtosecond lifetime of the virtual intermediate electronic state.

  11. 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 ( ...

  12. Abdomen X-Ray (Radiography)

    Science.gov (United States)

    ... Professions Site Index A-Z X-ray (Radiography) - Abdomen Abdominal x-ray uses a very small dose ... to produce pictures of the inside of the abdominal cavity. It is used to evaluate the stomach, liver, ...

  13. 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 ...

  14. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... patient. top of page How does the procedure work? X-rays are a form of radiation like ... very controlled x-ray beams and dose control methods to minimize stray (scatter) radiation. This ensures that ...

  15. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... radiation like light or radio waves. X-rays pass through most objects, including the body. Once it ... organs, allow more of the x-rays to pass through them. As a result, bones appear white ...

  16. 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 ... Your e-mail address: Personal message (optional): Bees: Wax: Notice: RadiologyInfo respects your privacy. Information entered here ...

  17. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... the body. X-rays are the oldest and most frequently used form of medical imaging. A bone ... bones. top of page How should I prepare? Most bone x-rays require no special preparation. You ...

  18. 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.

  19. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... of page What are some common uses of the procedure? A bone x-ray is used to: ... and x-rays. top of page What does the equipment look like? The equipment typically used for ...

  20. 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.

  1. X-Ray Exam: Hip

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Hip KidsHealth > For Parents > X-Ray Exam: Hip A A A What's in ... español Radiografía: cadera What It Is A hip X-ray is a safe and painless test that ...

  2. X-Ray Exam: Finger

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Finger KidsHealth > For Parents > X-Ray Exam: Finger A A A What's in ... español Radiografía: dedo What It Is A finger X-ray is a safe and painless test that ...

  3. X-Ray Exam: Foot

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Foot KidsHealth > For Parents > X-Ray Exam: Foot A A A What's in ... español Radiografía: pie What It Is A foot X-ray is a safe and painless test that ...

  4. X-Ray Exam: Wrist

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Wrist KidsHealth > For Parents > X-Ray Exam: Wrist A A A What's in ... español Radiografía: muñeca What It Is A wrist X-ray is a safe and painless test that ...

  5. X-Ray Exam: Ankle

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Ankle KidsHealth > For Parents > X-Ray Exam: Ankle A A A What's in ... español Radiografía: tobillo What It Is An ankle X-ray is a safe and painless test that ...

  6. X-Ray Exam: Pelvis

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Pelvis KidsHealth > For Parents > X-Ray Exam: Pelvis A A A What's in ... español Radiografía: pelvis What It Is A pelvis X-ray is a safe and painless test that ...

  7. X-Ray Exam: Forearm

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Forearm KidsHealth > For Parents > X-Ray Exam: Forearm A A A What's in ... español Radiografía: brazo What It Is A forearm X-ray is a safe and painless test that ...

  8. X-ray selected BALQSOs

    CERN Document Server

    Page, M J; Ceballos, M; Corral, A; Ebrero, J; Esquej, P; Krumpe, M; Mateos, S; Rosen, S; Schwope, A; Streblyanska, A; Symeonidis, M; Tedds, J A; Watson, M G

    2016-01-01

    We study a sample of six X-ray selected broad absorption line (BAL) quasi-stellar objects (QSOs) from the XMM-Newton Wide Angle Survey. All six objects are classified as BALQSOs using the classic balnicity index, and together they form the largest sample of X-ray selected BALQSOs. We find evidence for absorption in the X-ray spectra of all six objects. An ionized absorption model applied to an X-ray spectral shape that would be typical for non-BAL QSOs (a power law with energy index alpha=0.98) provides acceptable fits to the X-ray spectra of all six objects. The optical to X-ray spectral indices, alpha_OX, of the X-ray selected BALQSOs, have a mean value of 1.69 +- 0.05, which is similar to that found for X-ray selected and optically selected non-BAL QSOs of similar ultraviolet luminosity. In contrast, optically-selected BALQSOs typically have much larger alpha_OX and so are characterised as being X-ray weak. The results imply that X-ray selection yields intrinsically X-ray bright BALQSOs, but their X-ray sp...

  9. X-ray today

    Energy Technology Data Exchange (ETDEWEB)

    Neitzel, U. [Philips Medical Systems, Hamburg (Germany)

    2001-09-01

    The interest attracted by the new imaging modalities tends to overshadow the continuing importance of projection radiography and fluoroscopy. Nevertheless, projection techniques still represent by far the greatest proportion of diagnostic imaging examinations, and play an essential role in the growing number of advanced interventional procedures. This article describes some of the latest developments in X-ray imaging technology, using two products from the Philips range as examples: the Integris Allura cardiovascular system with 3D image reconstruction, and the BV Pulsera: a high-end, multi-functional mobile C-arm system with cardiac capabilities. (orig.)

  10. SMM x ray polychromator

    Science.gov (United States)

    Saba, J. L. R.

    1993-01-01

    The objective of the X-ray Polychromator (XRP) experiment was to study the physical properties of solar flare plasma and its relation to the parent active region to understand better the flare mechanism and related solar activity. Observations were made to determine the temperature, density, and dynamic structure of the pre-flare and flare plasma as a function of wavelength, space and time, the extent to which the flare plasma departs from thermal equilibrium, and the variation of this departure with time. The experiment also determines the temperature and density structure of active regions and flare-induced changes in the regions.

  11. Degradation process of lead chromate in paintings by Vincent van Gogh studied by means of synchrotron X-ray spectromicroscopy and related methods. 1. Artificially aged model samples.

    Science.gov (United States)

    Monico, Letizia; Van der Snickt, Geert; Janssens, Koen; De Nolf, Wout; Miliani, Costanza; Verbeeck, Johan; Tian, He; Tan, Haiyan; Dik, Joris; Radepont, Marie; Cotte, Marine

    2011-02-15

    On several paintings by artists of the end of the 19th century and the beginning of the 20th Century a darkening of the original yellow areas, painted with the chrome yellow pigment (PbCrO(4), PbCrO(4)·xPbSO(4), or PbCrO(4)·xPbO) is observed. The most famous of these are the various Sunflowers paintings Vincent van Gogh made during his career. In the first part of this work, we attempt to elucidate the degradation process of chrome yellow by studying artificially aged model samples. In view of the very thin (1-3 μm) alteration layers that are formed, high lateral resolution spectroscopic methods such as microscopic X-ray absorption near edge (μ-XANES), X-ray fluorescence spectrometry (μ-XRF), and electron energy loss spectrometry (EELS) were employed. Some of these use synchrotron radiation (SR). Additionally, microscopic SR X-ray diffraction (SR μ-XRD), μ-Raman, and mid-FTIR spectroscopy were employed to completely characterize the samples. The formation of Cr(III) compounds at the surface of the chrome yellow paint layers is particularly observed in one aged model sample taken from a historic paint tube (ca. 1914). About two-thirds of the chromium that is present at the surface has reduced from the hexavalent to the trivalent state. The EELS and μ-XANES spectra are consistent with the presence of Cr(2)O(3)·2H(2)O (viridian). Moreover, as demonstrated by μ-XANES, the presence of another Cr(III) compound, such as either Cr(2)(SO(4))(3)·H(2)O or (CH(3)CO(2))(7)Cr(3)(OH)(2) [chromium(III) acetate hydroxide], is likely.

  12. Use of X-ray fluorescence energy dispersive technique in the lead determination and other metals in excrements of otters (Lontra longicaudis)

    Energy Technology Data Exchange (ETDEWEB)

    Moraes, Liz Mary B.; Silva, Richard M.C.; Nascimento Filho, Virgilio F. [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Lab. de Instrumentacao Nuclear]. E-mail: lizmaryb@cena.usp.br; Ferreira, Carla Josef; Adriano, Leonardo R.; Ferreira, Jose Roberto [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil). Lab. de Ecotoxicologia

    2005-07-01

    This work had for objective to evaluate the contamination for Pb and other metals (Ti, Mn, Fe, Ni, Cu and Zn) in excrement samples of a neotropical otter population specie, found in river Betari, Alto Vale do Ribeira basin, Southeast Sao Paulo State. This river is a tributary of the Ribeira de Iguape river and part of its passage meets inside of the Parque Estadual Turistico do Alto Ribeira, one of the most conserved area of Brazilian Atlantic Forest. As the diet of these animals is based in fishes, it is an environmental interest in the determination of Pb in its excrements, since that is accumulating on the tropical chain path and in this region (in the decade of 1970) had the implanted a Pb extraction from galena mining. The analysis of the samples requires frequently the chemical digestion, with the disadvantages of being weak and expense. Aiming at to eliminate these disadvantages, the objective of the work was to use the X-ray fluorescence energy dispersive technique (EDXRF), for demanding a minimum preparation of the sample. Six excrement samples had been frozen, lyophilized and cryogenically milled, and after analyzed as pellet form, using a X-ray tube (target Mo, Zr filter, 25 kV/10 mA) and Si(Li) semiconductor spectrometer. The concentration was varied from 5.0 to 15.4 {mu}g g{sup -1} and it was possible also quantified other metals, showing maximum concentrations: Ti - 308, Mn - 38, Fe - 1131, Ni - 44, Cu . 2.8 and Zn . 92.4 {mu}g g{sup -1}. (author)

  13. Topological X-Rays Revisited

    Science.gov (United States)

    Lynch, Mark

    2012-01-01

    We continue our study of topological X-rays begun in Lynch ["Topological X-rays and MRI's," iJMEST 33(3) (2002), pp. 389-392]. We modify our definition of a topological magnetic resonance imaging and give an affirmative answer to the question posed there: Can we identify a closed set in a box by defining X-rays to probe the interior and without…

  14. 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.

  15. 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.

  16. 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...

  17. Soft X-ray optics

    CERN Document Server

    Spiller, Eberhard A

    1993-01-01

    This text describes optics mainly in the 10 to 500 angstrom wavelength region. These wavelengths are 50 to 100 times shorter than those for visible light and 50 to 100 times longer than the wavelengths of medical x rays or x-ray diffraction from natural crystals. There have been substantial advances during the last 20 years, which one can see as an extension of optical technology to shorter wavelengths or as an extension of x-ray diffraction to longer wavelengths. Artificial diffracting structures like zone plates and multilayer mirrors are replacing the natural crystals of x-ray diffraction.

  18. Supergiant Fast X-ray Transients

    CERN Document Server

    Sidoli, Lara

    2011-01-01

    The phenomenology of a subclass of High Mass X-ray Binaries hosting a blue supergiant companion, the so-called Supergiant Fast X-ray Transients (SFXTs), is reviewed. Their number is growing, mainly thanks to the discoveries performed by the INTEGRAL satellite, then followed by soft X-rays observations (both aimed at refining the source position and at monitoring the source behavior) leading to the optical identification of the blue supergiant nature of the donor star. Their defining properties are a transient X-ray activity consisting of sporadic, fast and bright flares, (each with a variable duration between a few minutes and a few hours), reaching 1E36-1E37 erg/s. The quiescence is at a luminosity of 1E32 erg/s, while their more frequent state consists of an intermediate X-ray emission of 1E33-1E34 erg/s (1-10 keV). Only the brightest flares are detected by INTEGRAL (>17 keV) during short pointings, with no detected persistent emission. The physical mechanism driving the short outbursts is still debated, al...

  19. X-ray optics developments at ESA

    DEFF Research Database (Denmark)

    Bavdaz, M.; Wille, E.; Wallace, K.;

    2013-01-01

    ) in collaboration with research institutions and industry, enabling leading-edge future science missions. Silicon Pore Optics (SPO) [1 to 21] and Slumped Glass Optics (SGO) [22 to 29] are lightweight high performance X-ray optics technologies being developed in Europe, driven by applications in observatory class......Future high energy astrophysics missions will require high performance novel X-ray optics to explore the Universe beyond the limits of the currently operating Chandra and Newton observatories. Innovative optics technologies are therefore being developed and matured by the European Space Agency (ESA...... reflective coatings [30 to 35]. In addition, the progress with the X-ray test facilities and associated beam-lines is discussed [36]. © (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only....

  20. X-ray signals in renal osteopathy

    Energy Technology Data Exchange (ETDEWEB)

    Rieden, K.

    1984-10-01

    Chronic renal insufficiency is associated with metabolic disturbances which ultimately lead to typical, partly extremely painful changes in the skeletal system the longer the disease persists. Regular X-ray control of certain skeletal segments allows early detection of renal oesteopathy if the radiological findings described in this article are carefully scrutinised and interpreted.

  1. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... bone absorbs much of the radiation while soft tissue, such as muscle, fat and organs, allow more of the x-rays to pass through them. As a result, bones appear white on the x-ray, soft tissue shows up in shades of gray and air ...

  2. X-Ray Diffraction Apparatus

    Science.gov (United States)

    Blake, David F. (Inventor); Bryson, Charles (Inventor); Freund, Friedmann (Inventor)

    1996-01-01

    An x-ray diffraction apparatus for use in analyzing the x-ray diffraction pattern of a sample is introduced. The apparatus includes a beam source for generating a collimated x-ray beam having one or more discrete x-ray energies, a holder for holding the sample to be analyzed in the path of the beam, and a charge-coupled device having an array of pixels for detecting, in one or more selected photon energy ranges, x-ray diffraction photons produced by irradiating such a sample with said beam. The CCD is coupled to an output unit which receives input information relating to the energies of photons striking each pixel in the CCD, and constructs the diffraction pattern of photons within a selected energy range striking the CCD.

  3. Focusing X-Ray Telescopes

    Science.gov (United States)

    O'Dell, Stephen; Brissenden, Roger; Davis, William; Elsner, Ronald; Elvis, Martin; Freeman, Mark; Gaetz, Terrance; Gorenstein, Paul; Gubarev, Mikhall; Jerlus, Diab; Juda, Michael; Kolodziejczak, Jeffrey; Murray, Stephen; Petre, Robert; Podgorski, William; Ramsey, Brian; Reid, Paul; Saha, Timo; Wolk, Scott; Troller-McKinstry, Susan; Weisskopf, Martin; Wilke, Rudeger; Zhang, William

    2010-01-01

    During the half-century history of x-ray astronomy, focusing x-ray telescopes, through increased effective area and finer angular resolution, have improved sensitivity by 8 orders of magnitude. Here, we review previous and current x-ray-telescope missions. Next, we describe the planned next-generation x-ray-astronomy facility, the International X-ray Observatory (IXO). We conclude with an overview of a concept for the next next-generation facility, Generation X. Its scientific objectives will require very large areas (about 10,000 sq m) of highly-nested, lightweight grazing-incidence mirrors, with exceptional (about 0.1-arcsec) resolution. Achieving this angular resolution with lightweight mirrors will likely require on-orbit adjustment of alignment and figure.

  4. X-Ray Tomographic Reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Bonnie Schmittberger

    2010-08-25

    Tomographic scans have revolutionized imaging techniques used in medical and biological research by resolving individual sample slices instead of several superimposed images that are obtained from regular x-ray scans. X-Ray fluorescence computed tomography, a more specific tomography technique, bombards the sample with synchrotron x-rays and detects the fluorescent photons emitted from the sample. However, since x-rays are attenuated as they pass through the sample, tomographic scans often produce images with erroneous low densities in areas where the x-rays have already passed through most of the sample. To correct for this and correctly reconstruct the data in order to obtain the most accurate images, a program employing iterative methods based on the inverse Radon transform was written. Applying this reconstruction method to a tomographic image recovered some of the lost densities, providing a more accurate image from which element concentrations and internal structure can be determined.

  5. X-ray monitoring optical elements

    Energy Technology Data Exchange (ETDEWEB)

    Stoupin, Stanislav; Shvydko, Yury; Katsoudas, John; Blank, Vladimir D.; Terentyev, Sergey A.

    2016-12-27

    An X-ray article and method for analyzing hard X-rays which have interacted with a test system. The X-ray article is operative to diffract or otherwise process X-rays from an input X-ray beam which have interacted with the test system and at the same time provide an electrical circuit adapted to collect photoelectrons emitted from an X-ray optical element of the X-ray article to analyze features of the test system.

  6. X-ray diagnostics for TFTR

    Energy Technology Data Exchange (ETDEWEB)

    von Goeler, S.; Hill, K.W.; Bitter, M.

    1982-12-01

    A short description of the x-ray diagnostic preparation for the TFTR tokamak is given. The x-ray equipment consists of the limiter x-ray monitoring system, the soft x-ray pulse-height-analysis-system, the soft x-ray imaging system and the x-ray crystal spectrometer. Particular attention is given to the radiation protection of the x-ray systems from the neutron environment.

  7. Surface and interface analysis of a Roman lead pipe ``fistula'': microchemistry of the soldering at the join, as seen by scanning Auger microscopy and X-ray photoelectron spectroscopy

    Science.gov (United States)

    Paparazzo, Ernesto

    1994-01-01

    Scanning Auger microscopy (SAM) and X-ray photoelectron spectroscopy (XPS) are used to study the surface and interface chemical composition of a Roman lead pipe (fistula). Experimental evidence is provided that the Romans used tin for soldering the join, and the chemical nature of the single elements, e.g. whether in metallic or combined form, is identified. SAM discloses the segregation of the chemical elements with a sub-micron spatial resolution, and large deviations in the quantitative results are found relative to the large-area averaged XPS results. Elemental depth profiles are obtained from all over the body of the pipe: we find that the lead is less oxidized at the join, and this region contains many more hydrocarbon species, which we interpret as deriving from the use of oil for anti-oxidizing purposes. Our experimental findings are consistent with Plinius' report on the lead-tin soldering techniques used in the Roman world.

  8. 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...

  9. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... are easily accessible and are frequently compared to current x-ray images for diagnosis and disease management. ... of North America, Inc. (RSNA). To help ensure current and accurate information, we do not permit copying ...

  10. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... patients and physicians. Because x-ray imaging is fast and easy, it is particularly useful in emergency ... diagnosis and treatment of the individual patient's condition. Ultrasound imaging, which uses sound waves instead of ionizing ...

  11. 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...

  12. CELESTIAL X-RAY SOURCES.

    Science.gov (United States)

    sources, (4) the physical conditions in the pulsating x-ray source in the Crab Nebula , and (5) miscellaneous related topics. A bibliography of all work performed under the contract is given. (Author)

  13. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... ionizing radiation to produce pictures of any bone in the body. It is commonly used to diagnose ... bone x-ray makes images of any bone in the body, including the hand, wrist, arm, elbow, ...

  14. Bone X-Ray (Radiography)

    Science.gov (United States)

    ... bony fragments following treatment of a fracture. guide orthopedic surgery, such as spine repair/fusion, joint replacement ... A portable x-ray machine is a compact apparatus that can be taken to the patient in ...

  15. 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? ... these links. About Us | Contact Us | FAQ | Privacy | Terms of Use | Links | Site Map Copyright © 2017 Radiological ...

  16. 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.

  17. 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)

  18. 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)

  19. X-Rays, Pregnancy and You

    Science.gov (United States)

    ... and Procedures Medical Imaging Medical X-ray Imaging X-Rays, Pregnancy and You Share Tweet Linkedin Pin ... the decision with your doctor. What Kind of X-Rays Can Affect the Unborn Child? During most ...

  20. X-ray shout echoing through space

    Science.gov (United States)

    2004-01-01

    observatories around the world were pointing their instruments at this mysterious source in the sky, named GRB 031203, in the attempt to decipher its nature. Also ESA's X-ray observatory, XMM-Newton, joined the hunt and observed the source in detail, using its on-board European Photon Imaging Camera (EPIC). The fading X-ray emission from GRB 031203 - called the `afterglow' - is clearly seen in XMM-Newton's images. But much more stunning are the two rings, centred on the afterglow, which appear to expand thousand times faster than the speed of light. Dr. Simon Vaughan, of the University of Leicester, United Kingdom, leads an international team of scientists studying GRB 031203. He explains that these rings are what astronomers call an `echo'. They form when the X-rays from the distant gamma-ray burst shine on a layer of dust in our own Galaxy. "The dust scatters some of the X-rays, causing XMM-Newton to observe these rings, much in the same way as fog scatters the light from a car's headlights," said Vaughan. Although the afterglow is the brightest feature seen in XMM-Newton's images, the expanding echo is much more spectacular. "It is like a shout in a cathedral," Vaughan said. "The shout of the gamma-ray burst is louder, but the Galactic reverberation, seen as the rings, is much more beautiful." The rings seem to expand because the X-rays scattered by dust farther from the direction of GRB 031203 take longer to reach us than those hitting the dust closer to the line of sight. However, nothing can move faster than light. "This is precisely what we expect because of the finite speed of light," said Vaughan. "The rate of expansion that we see is just a visual effect." He and his colleagues explain that we see two rings because there are two thin sheets of dust between the source of the gamma-ray burst and Earth, one closer to us creating the wider ring and one further away where the smaller ring is formed. Since they know precisely at what speed the X-ray light travels in space

  1. Methods of Attosecond X-Ray Pulse Generation

    CERN Document Server

    Zholents, Alexander

    2005-01-01

    Our attitude towards attosecond x-ray pulses has changed dramatically over the past several years. Not long ago x-ray pulses with a duration of a few hundred attoseconds were just science fiction for most of us, but they are already a tool for some researchers in present days. Breakthrough progress in the generation of solitary soft x-ray pulses of attosecond duration has been made by the laser community. Following this lead, people in the free electron laser community have begun to develop new ideas on how to generate attosecond x-ray pulses in the hard x-ray energy range. In this report I will review some of these ideas.

  2. X-ray Echo Spectroscopy.

    Science.gov (United States)

    Shvyd'ko, Yuri

    2016-02-26

    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 >10^{8}) with broadband ≃5-13  meV dispersing systems are introduced featuring more than 10^{3} signal enhancement. The technique is general, applicable in different photon frequency domains.

  3. 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.

  4. 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...

  5. Connections between X-ray and optical variability in the low mass X-ray binary 1735-444

    Science.gov (United States)

    Corbet, R. H. D.; Smale, A. P.; Charles, P. A.; Lewin, W. H. G.; Menzies, J. W.

    1989-01-01

    The results of a long duration (4 day) simultaneous optical and X-ray observation of the low mass X-ray binary 1735-444 are presented. The observed X-ray and optical fluxes are correlated; the strength of this correlation is increased when allowance is made for the relatively large orbital modulation of the optical light. A simple interpretation of the optical radiation as reprocessed X-rays in a blackbody disk leads to an implausibly low disk temperature if the disk is assumed to have constant geometry. 1735-444 exhibits bimodal behavior having an X-ray spectral hardness ratio versus source intensity which is similar to that previously seen in sources such as Cyg X-2.

  6. Quantum effets in nonresonant X-ray scattering

    Energy Technology Data Exchange (ETDEWEB)

    Slowik, Jan Malte

    2015-11-15

    Due to their versatile properties, X rays are a unique tool to investigate the structure and dynamics of matter. X-ray scattering is the fundamental principle of many imaging techniques. Examples are X-ray crystallography, which recently celebrated one hundred years and is currently the leading method in structure determination of proteins, as well as X-ray phase contrast imaging (PCI), which is an imaging technique with countless applications in biology, medicine, etc. The technological development of X-ray free electron lasers (XFEL) has brought X-ray imaging at the edge of a new scientific revolution. XFELs offer ultrashort X-ray pulses with unprecedented high X-ray fluence and excellent spatial coherence properties. These properties make them an outstanding radiation source for X-ray scattering experiments, providing ultrafast temporal resolution as well as atomic spatial resolution. However, the radiation-matter interaction in XFEL experiments also advances into a novel regime. This demands a sound theoretical fundament to describe and explore the new experimental possibilities. This dissertation is dedicated to the theoretical study of nonresonant X-ray scattering. As the first topic, I consider the near-field imaging by propagation based X-ray phase contrast imaging (PCI). I devise a novel theory of PCI, in which radiation and matter are quantized. Remarkably, the crucial interference term automatically excludes contributions from inelastic scattering. This explains the success of the classical description thus far. The second topic of the thesis is the X-ray imaging of coherent electronic motion, where quantum effects become particularly apparent. The electron density of coherent electronic wave packets - important in charge transfer and bond breaking - varies in time, typically on femto- or attosecond time scales. In the near future, XFELs are envisaged to provide attosecond X-ray pulses, opening the possibility for time-resolved ultrafast X-ray scattering

  7. Neutron and X-ray Spectroscopy

    CERN Document Server

    Hippert, Françoise; Hodeau, Jean Louis; Lelièvre-Berna, Eddy; Regnard, Jean-René

    2006-01-01

    Neutron and X-Ray Spectroscopy delivers an up-to-date account of the principles and practice of inelastic and spectroscopic methods available at neutron and synchrotron sources, including recent developments. The chapters are based on a course of lectures and practicals (the HERCULES course) delivered to young scientists who require these methods in their professional careers. Each chapter, written by a leading specialist in the field, introduces the basic concepts of the technique and provides an overview of recent work. This volume, which focuses on spectroscopic techniques in synchrotron radiation and inelastic neutron scattering, will be a primary source of information for physicists, chemists and materials scientists who wish to acquire a basic understanding of these techniques and to discover the possibilities offered by them. Emphasizing the complementarity of the neutron and X-ray methods, this tutorial will also be invaluable to scientists already working in neighboring fields who seek to extend thei...

  8. 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.

  9. Anisotropic imaging performance in indirect x-ray imaging detectors.

    Science.gov (United States)

    Badano, Aldo; Kyprianou, Iacovos S; Sempau, Josep

    2006-08-01

    We report on the variability in imaging system performance due to oblique x-ray incidence, and the associated transport of quanta (both x rays and optical photons) through the phosphor, in columnar indirect digital detectors. The analysis uses MANTIS, a combined x-ray, electron, and optical Monte Carlo transport code freely available. We describe the main features of the simulation method and provide some validation of the phosphor screen models considered in this work. We report x-ray and electron three-dimensional energy deposition distributions and point-response functions (PRFs), including optical spread in columnar phosphor screens of thickness 100 and 500 microm, for 19, 39, 59, and 79 keV monoenergetic x-ray beams incident at 0 degrees, 10 degrees, and 15 degrees. In addition, we present pulse-height spectra for the same phosphor thickness, x-ray energies, and angles of incidence. Our results suggest that the PRF due to the phosphor blur is highly nonsymmetrical, and that the resolution properties of a columnar screen in a tomographic, or tomosynthetic imaging system varies significantly with the angle of x-ray incidence. Moreover, we find that the noise due to the variability in the number of light photons detected per primary x-ray interaction, summarized in the information or Swank factor, is somewhat independent of thickness and incidence angle of the x-ray beam. Our results also suggest that the anisotropy in the PRF is not less in screens with absorptive backings, while the noise introduced by variations in the gain and optical transport is larger. Predictions from MANTIS, after additional validation, can provide the needed understanding of the extent of such variations, and eventually, lead to the incorporation of the changes in imaging performance with incidence angle into the reconstruction algorithms for volumetric x-ray imaging systems.

  10. Elimination of Airborne Lead Contamination from Caliber .22 Ammunition.

    Science.gov (United States)

    1987-06-01

    composition is comprised of the toxic heavy metals: lead and barium . The barium , however, is considered a minor contributor to the contamination...lead styphnate priming mixture and 2.9 grains of Winchester (WC371) propellant. This propellant quantity resulted in near the maximum recommended...standard lead styphnate primer mixture to four times the volume of the lead styphnate primer mixture. The amount of new primer mixture which produced

  11. Long X-ray burst monitoring with INTEGRAL

    DEFF Research Database (Denmark)

    X-ray bursts are thermonuclear explosions on the surface of accreting neutron stars in low mass X-ray binary systems. In the frame of the INTEGRAL observational Key Programme over the Galactic Center a good number of the known X-ray bursters are frequently being monitored. An international...... collaboration lead by the JEM-X team at the Danish National Space Center has proposed to exploit the improved sensitivity of the INTEGRAL instruments to investigate the observational properties and physics up to high energies of exceptional burst events lasting between a few tens of minutes and several hours...

  12. Stellar X-Ray Polarimetry

    Science.gov (United States)

    Swank, J.

    2011-01-01

    Most of the stellar end-state black holes, pulsars, and white dwarfs that are X-ray sources should have polarized X-ray fluxes. The degree will depend on the relative contributions of the unresolved structures. Fluxes from accretion disks and accretion disk corona may be polarized by scattering. Beams and jets may have contributions of polarized emission in strong magnetic fields. The Gravity and Extreme Magnetism Small Explorer (GEMS) will study the effects on polarization of strong gravity of black holes and strong magnetism of neutron stars. Some part of the flux from compact stars accreting from companion stars has been reflected from the companion, its wind, or accretion streams. Polarization of this component is a potential tool for studying the structure of the gas in these binary systems. Polarization due to scattering can also be present in X-ray emission from white dwarf binaries and binary normal stars such as RS CVn stars and colliding wind sources like Eta Car. Normal late type stars may have polarized flux from coronal flares. But X-ray polarization sensitivity is not at the level needed for single early type stars.

  13. 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.

  14. X-rays and magnetism.

    Science.gov (United States)

    Fischer, Peter; Ohldag, Hendrik

    2015-09-01

    Magnetism is among the most active and attractive areas in modern solid state physics because of intriguing phenomena interesting to fundamental research and a manifold of technological applications. State-of-the-art synthesis of advanced magnetic materials, e.g. in hybrid structures paves the way to new functionalities. To characterize modern magnetic materials and the associated magnetic phenomena, polarized x-rays have emerged as unique probes due to their specific interaction with magnetic materials. A large variety of spectroscopic and microscopic techniques have been developed to quantify in an element, valence and site-sensitive way properties of ferro-, ferri-, and antiferromagnetic systems, such as spin and orbital moments, and to image nanoscale spin textures and their dynamics with sub-ns time and almost 10 nm spatial resolution. The enormous intensity of x-rays and their degree of coherence at next generation x-ray facilities will open the fsec time window to magnetic studies addressing fundamental time scales in magnetism with nanometer spatial resolution. This review will give an introduction into contemporary topics of nanoscale magnetic materials and provide an overview of analytical spectroscopy and microscopy tools based on x-ray dichroism effects. Selected examples of current research will demonstrate the potential and future directions of these techniques.

  15. 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.

  16. Alpha proton x ray spectrometer

    Science.gov (United States)

    Rieder, Rudi; Waeke, H.; Economou, T.

    1994-01-01

    Mars Pathfinder will carry an alpha-proton x ray spectrometer (APX) for the determination of the elemental chemical composition of Martian rocks and soils. The instrument will measure the concentration of all major and some minor elements, including C, N, and O at levels above typically 1 percent.

  17. 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 ( ...

  18. 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 About Us News Physician ... An x-ray (radiograph) is a noninvasive medical test that helps physicians diagnose and treat medical conditions. ...

  19. 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...

  20. 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.

  1. 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.

  2. Be/X-ray binaries

    CERN Document Server

    Reig, Pablo

    2011-01-01

    The purpose of this work is to review the observational properties of Be/X-ray binaries. The open questions in Be/X-ray binaries include those related to the Be star companion, that is, the so-called "Be phenomenon", such as, timescales associated to the formation and dissipation of the equatorial disc, mass-ejection mechanisms, V/R variability, and rotation rates; those related to the neutron star, such as, mass determination, accretion physics, and spin period evolution; but also, those that result from the interaction of the two constituents, such as, disc truncation and mass transfer. Until recently, it was thought that the Be stars' disc was not significantly affected by the neutron star. In this review, I present the observational evidence accumulated in recent years on the interaction between the circumstellar disc and the compact companion. The most obvious effect is the tidal truncation of the disc. As a result, the equatorial discs in Be/X-ray binaries are smaller and denser than those around isolat...

  3. Magnetically Confined Wind Shocks in X-rays - a Review

    CERN Document Server

    ud-Doula, Asif

    2015-01-01

    A subset (~ 10%) of massive stars present strong, globally ordered (mostly dipolar) magnetic fields. The trapping and channeling of their stellar winds in closed magnetic loops leads to magnetically confined wind shocks (MCWS), with pre-shock flow speeds that are some fraction of the wind terminal speed. These shocks generate hot plasma, a source of X-rays. In the last decade, several developments took place, notably the determination of the hot plasma properties for a large sample of objects using XMM-Newton and Chandra, as well as fully self-consistent MHD modelling and the identification of shock retreat effects in weak winds. Despite a few exceptions, the combination of magnetic confinement, shock retreat and rotation effects seems to be able to account for X-ray emission in massive OB stars. Here we review these new observational and theoretical aspects of this X-ray emission and envisage some perspectives for the next generation of X-ray observatories.

  4. Thermal detectors as single photon X-ray spectrometers

    Science.gov (United States)

    Moseley, S. H.; Kelley, R. L.; Mather, J. C.; Mushotzky, R. F.; Szymkowiak, A. E.; Mccammon, D.

    1985-01-01

    In a thermal detector employed for X-ray spectroscopy applications, the energy of an X-ray is converted to heat in a small mass, and the energy of that X-ray inferred from the size of the temperature rise. The present investigation is concerned with the possibility to make an extremely low heat capacity calorimeter which can be employed as a thermal detector. Several types of calorimeters were fabricated and tested at temperatures as low as approximately 0.05 K. The obtained devices make use of thermistors constructed of melt-doped silicon, nuclear transmutation doped (NTD) germanium, and ion-implanted silicon with a variety of materials for the support and electrical leads. The utility of these microcalorimeters as X-ray spectrometers could be verified.

  5. 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.

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

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Scoliosis KidsHealth > For Parents > X-Ray Exam: Scoliosis A A A What's in ... español Radiografía: escoliosis What It Is A scoliosis X-ray is a relatively safe and painless test ...

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

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Neck KidsHealth > For Parents > X-Ray Exam: Neck A A A What's in ... español Radiografía: cuello What It Is A neck X-ray is a safe and painless test that ...

  8. X-Ray Exam: Femur (Upper Leg)

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Femur (Upper Leg) KidsHealth > For Parents > X-Ray Exam: Femur (Upper Leg) A A A ... español Radiografía: fémur What It Is A femur X-ray is a safe and painless test that ...

  9. X-Ray Exam: Cervical Spine

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Cervical Spine KidsHealth > For Parents > X-Ray Exam: Cervical Spine A A A What's ... columna cervical What It Is A cervical spine X-ray is a safe and painless test that ...

  10. Attosecond Hard X-ray Free Electron Laser

    Directory of Open Access Journals (Sweden)

    Sandeep Kumar

    2013-03-01

    Full Text Available In this paper, several schemes of soft X-ray and hard X-ray free electron lasers (XFEL and their progress are reviewed. Self-amplified spontaneous emission (SASE schemes, the high gain harmonic generation (HGHG scheme and various enhancement schemes through seeding and beam manipulations are discussed, especially in view of the generation of attosecond X-ray pulses. Our recent work on the generation of attosecond hard X-ray pulses is also discussed. In our study, the enhanced SASE scheme is utilized, using electron beam parameters of an XFEL under construction at Pohang Accelerator Laboratory (PAL. Laser, chicane and electron beam parameters are optimized to generate an isolated attosecond hard X-ray pulse at 0.1 nm (12.4 keV. The simulations show that the manipulation of electron energy beam profile may lead to the generation of an isolated attosecond hard X-ray of 150 attosecond pulse at 0.1 nm.

  11. X-MIME: An Imaging X-ray Spectrometer for Detailed Study of Jupiter's Icy Moons and the Planet's X-ray Aurora

    Science.gov (United States)

    Elsner, R. F.; Ramsey, B. D.; Waite, J. H.; Rehak, P.; Johnson, R. E.; Cooper, J. F.; Swartz, D. A.

    2004-01-01

    Remote observations with the Chandra X-ray Observatory and the XMM-Newton Observatory have shown that the Jovian system is a source of x-rays with a rich and complicated structure. The planet's polar auroral zones and its disk are powerful sources of x-ray emission. Chandra observations revealed x-ray emission from the Io Plasma Torus and from the Galilean moons Io, Europa, and possibly Ganymede. The emission from these moons is certainly due to bombardment of their surfaces of highly energetic protons, oxygen and sulfur ions from the region near the Torus exciting atoms in their surfaces and leading to fluorescent x-ray emission lines. Although the x-ray emission from the Galilean moons is faint when observed from Earth orbit, an imaging x-ray spectrometer in orbit around these moons, operating at 200 eV and above with 150 eV energy resolution, would provide a detailed mapping (down to 40 m spatial resolution) of the elemental composition in their surfaces. Such maps would provide important constraints on formation and evolution scenarios for the surfaces of these moons. Here we describe the characteristics of X-MIME, an imaging x-ray spectrometer under going a feasibility study for the JIMO mission, with the ultimate goal of providing unprecedented x-ray studies of the elemental composition of the surfaces of Jupiter's icy moons and Io, as well as of Jupiter's auroral x-ray emission.

  12. 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.

  13. X-Ray Visions of SS Cygni

    Science.gov (United States)

    Young, D. L.

    2004-12-01

    The Chandra X-Ray Observatory is the most sophisticated X-ray observatory launched by NASA. Chandra is designed to observe X-rays from highenergy regions of the universe, such as X-ray binary stars. On September 14, 2000, triggered by alerts from amateur astronomers worldwide, Chandra observed the outburst of the brightest northern dwarf nova SS Cygni. The cooperation of hundreds of amateur variable star astronomers and the Chandra X-Ray scientists and spacecraft specialists provided proof that the collaboration of amateur and professional astronomers is a powerful tool to study cosmic phenomena.

  14. X-rays from solar system objects

    CERN Document Server

    Bhardwaj, Anil; Gladstone, G Randall; Cravens, Thomas E; Lisse, Carey M; Dennerl, Konrad; Branduardi-Raymont, Graziella; Wargelin, Bradford J; Waite, J Hunter; Robertson, Ina; Ostgaard, Nikolai; Beiersdorfer, Peter; Snowden, Steven L; Kharchenko, Vasili; 10.1016/j.pss.2006.11.009

    2010-01-01

    During the last few years our knowledge about the X-ray emission from bodies within the solar system has significantly improved. Several new solar system objects are now known to shine in X-rays at energies below 2 keV. Apart from the Sun, the known X-ray emitters now include planets (Venus, Earth, Mars, Jupiter, and Saturn), planetary satellites (Moon, Io, Europa, and Ganymede), all active comets, the Io plasma torus (IPT), the rings of Saturn, the coronae (exospheres) of Earth and Mars, and the heliosphere. The advent of higher-resolution X-ray spectroscopy with the Chandra and XMM-Newton X-ray observatories has been of great benefit in advancing the field of planetary X-ray astronomy. Progress in modeling X-ray emission, laboratory studies of X-ray production, and theoretical calculations of cross-sections, have all contributed to our understanding of processes that produce X-rays from the solar system bodies. At Jupiter and Earth, both auroral and non-auroral disk X-ray emissions have been observed. X-ray...

  15. Soft X-ray induced damage in PVA-based membranes in water environment monitored by X-ray absorption spectroscopy

    Science.gov (United States)

    Tzvetkov, George; Späth, Andreas; Fink, Rainer H.

    2014-10-01

    The effect of synchrotron X-ray flux in a soft X-ray scanning-transmission microspectroscope (STXM) instrument on the chemical structure of air-filled poly(vinyl alcohol) (PVA) based microbubbles and their stabilizing shell has been examined. Prolonged soft X-ray illumination of the particles in aqueous suspension leads to the breaking of the microbubbles' protective polymer shell and substantial chemical changes. The latter were clarified via a micro-spot C K-edge near-edge X-ray absorption fine structure (NEXAFS) spectroscopy with further respect to the absorbed X-ray doses. Our results revealed a continuous degradation of the PVA network associated with formation of carbonyl- and carboxyl-containing species as well as an increased content of unsaturated bonds. The observed effects must be taken into account in studies of micro- and nanostructured polymer materials utilizing X-rays.

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

    Science.gov (United States)

    Sun, Tianxi; Macdonald, C A

    2013-02-07

    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.

  17. Long bone X-ray image stitching using Camera Augmented Mobile C-arm.

    Science.gov (United States)

    Wang, Lejing; Traub, Joerg; Heining, Sandro Michael; Benhimane, Selim; Euler, Ekkehard; Graumann, Rainer; Navab, Nassir

    2008-01-01

    X-ray images are widely used during surgery for long bone fracture fixation. Mobile C-arms provide X-ray images which are used to determine the quality of trauma reduction, i.e. the extremity length and mechanical axis of long bones. Standard X-ray images have a narrow field of view and can not visualize the entire long bone on a single image. In this paper, we propose a novel method to generate panoramic X-ray images in real time by using the previously introduced Camera Augmented Mobile C-arm. This advanced mobile C-arm system acquires registered X-ray and optical images by construction, which facilitates the generation of panoramic X-ray images based on first stitching the optical images and then embedding the X-ray images. We additionally introduce a method to reduce the parallax effect that leads to the blurring and measurement error on panoramic X-ray images. Visual marker tracking is employed to automatically stitch the sequence of video images and to rectify images. Our proposed method is suitable for intra-operative usage generating panoramic X-ray images, which enable metric measurements, with less radiation and without requirement of fronto-parallel setup and overlapping X-ray images. The results show that the panoramic X-ray images generated by our method are accurate enough (errors less than 1%) for metric measurements and suitable for many clinical applications in trauma reduction.

  18. Enhanced dynamic range x-ray imaging.

    Science.gov (United States)

    Haidekker, Mark A; Morrison, Logan Dain-Kelley; Sharma, Ajay; Burke, Emily

    2017-03-01

    X-ray images can suffer from excess contrast. Often, image exposure is chosen to visually optimize the region of interest, but at the expense of over- and underexposed regions elsewhere in the image. When image values are interpreted quantitatively as projected absorption, both over- and underexposure leads to the loss of quantitative information. We propose to combine multiple exposures into a composite that uses only pixels from those exposures in which they are neither under- nor overexposed. The composite image is created in analogy to visible-light high dynamic range photography. We present the mathematical framework for the recovery of absorbance from such composite images and demonstrate the method with biological and non-biological samples. We also show with an aluminum step-wedge that accurate recovery of step thickness from the absorbance values is possible, thereby highlighting the quantitative nature of the presented method. Due to the higher amount of detail encoded in an enhanced dynamic range x-ray image, we expect that the number of retaken images can be reduced, and patient exposure overall reduced. We also envision that the method can improve dual energy absorptiometry and even computed tomography by reducing the number of low-exposure ("photon-starved") projections.

  19. X-ray spectrometry and X-ray microtomography techniques for soil and geological samples analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kubala-Kukuś, A.; Banaś, D.; Braziewicz, J. [Institute of Physics, Jan Kochanowski University, ul. Świetokrzyska 15, 25-406 Kielce (Poland); Holycross Cancer Center, ul. Artwińskiego 3, 25-734 Kielce (Poland); Dziadowicz, M.; Kopeć, E. [Institute of Physics, Jan Kochanowski University, ul. Świetokrzyska 15, 25-406 Kielce (Poland); Majewska, U. [Institute of Physics, Jan Kochanowski University, ul. Świetokrzyska 15, 25-406 Kielce (Poland); Holycross Cancer Center, ul. Artwińskiego 3, 25-734 Kielce (Poland); Mazurek, M.; Pajek, M.; Sobisz, M.; Stabrawa, I. [Institute of Physics, Jan Kochanowski University, ul. Świetokrzyska 15, 25-406 Kielce (Poland); Wudarczyk-Moćko, J. [Holycross Cancer Center, ul. Artwińskiego 3, 25-734 Kielce (Poland); Góźdź, S. [Holycross Cancer Center, ul. Artwińskiego 3, 25-734 Kielce (Poland); Institute of Public Health, Jan Kochanowski University, IX Wieków Kielc 19, 25-317 Kielce (Poland)

    2015-12-01

    A particular subject of X-ray fluorescence analysis is its application in studies of the multielemental sample of composition in a wide range of concentrations, samples with different matrices, also inhomogeneous ones and those characterized with different grain size. Typical examples of these kinds of samples are soil or geological samples for which XRF elemental analysis may be difficult due to XRF disturbing effects. In this paper the WDXRF technique was applied in elemental analysis concerning different soil and geological samples (therapeutic mud, floral soil, brown soil, sandy soil, calcium aluminum cement). The sample morphology was analyzed using X-ray microtomography technique. The paper discusses the differences between the composition of samples, the influence of procedures with respect to the preparation of samples as regards their morphology and, finally, a quantitative analysis. The results of the studies were statistically tested (one-way ANOVA and correlation coefficients). For lead concentration determination in samples of sandy soil and cement-like matrix, the WDXRF spectrometer calibration was performed. The elemental analysis of the samples was complemented with knowledge of chemical composition obtained by X-ray powder diffraction.

  20. X-Ray Attenuation Cell

    Energy Technology Data Exchange (ETDEWEB)

    Ryutov, D.; Toor, A.

    2000-03-03

    To minimize the pulse-to-pulse variation, the LCLS FEL must operate at saturation, i.e. 10 orders of magnitude brighter spectral brilliance than 3rd-generation light sources. At this intensity, ultra-high vacuums and windowless transport are required. Many of the experiments, however, will need to be conducted at a much lower intensity thereby requiring a reliable means to reduce the x-ray intensity by many orders of magnitude without increasing the pulse-to-pulse variation. In this report we consider a possible solution for controlled attenuation of the LCLS x-ray radiation. We suggest using for this purpose a windowless gas-filled cell with the differential pumping. Although this scheme is easily realizable in principle, it has to be demonstrated that the attenuator can be made short enough to be practical and that the gas loads delivered to the vacuum line of sight (LOS) are acceptable. We are not going to present a final, optimized design. Instead, we will provide a preliminary analysis showing that the whole concept is robust and is worth further study. The spatial structure of the LCLS x-ray pulse at the location of the attenuator is shown in Fig. 1. The central high-intensity component, due to the FEL, has a FWHM of {approx}100 {micro}m. A second component, due to the undulator's broad band spontaneous radiation is seen as a much lower intensity ''halo'' with a FWHM of 1 mm. We discuss two versions of the attenuation cell. The first is directed towards a controlled attenuation of the FEL up to the 4 orders of magnitude in the intensity, with the spontaneous radiation halo being eliminated by collimators. In the second version, the spontaneous radiation is not sacrificed but the FEL component (as well as the first harmonic of the spontaneous radiation) gets attenuated by a more modest factor up to 100. We will make all the estimates assuming that the gas used in the attenuator is Xenon and that the energy of the FEL is 8.25 keV. At

  1. Controlling X-rays With Light

    Energy Technology Data Exchange (ETDEWEB)

    Glover, Ernie; Hertlein, Marcus; Southworth, Steve; Allison, Tom; van Tilborg, Jeroen; Kanter, Elliot; Krassig, B.; Varma, H.; Rude, Bruce; Santra, Robin; Belkacem, Ali; Young, Linda

    2010-08-02

    Ultrafast x-ray science is an exciting frontier that promises the visualization of electronic, atomic and molecular dynamics on atomic time and length scales. A largelyunexplored area of ultrafast x-ray science is the use of light to control how x-rays interact with matter. In order to extend control concepts established for long wavelengthprobes to the x-ray regime, the optical control field must drive a coherent electronic response on a timescale comparable to femtosecond core-hole lifetimes. An intense field is required to achieve this rapid response. Here an intense optical control pulse isobserved to efficiently modulate photoelectric absorption for x-rays and to create an ultrafast transparency window. We demonstrate an application of x-ray transparencyrelevant to ultrafast x-ray sources: an all-photonic temporal cross-correlation measurement of a femtosecond x-ray pulse. The ability to control x-ray/matterinteractions with light will create new opportunities at current and next-generation x-ray light sources.

  2. Research on cause of lead poisoning in children with a portable X - Ray fluorescence analyzer%便携式X线荧光分析仪用于儿童铅中毒溯源的研究

    Institute of Scientific and Technical Information of China (English)

    林国桢; 李科; 刘翔翊

    2012-01-01

    Objective:To evaluate the feasibility of a .portable X - Ray Fluorescence Analyzer (XRF) in searching the cause of pediatric lead poisoning. Methods:In a family with two children confirmed as lead poisoning, all articles that the children could reach or may be affected (including wall, furniture, foodstuff, dishware, water and toys) were detected for lead contents with a XRF to find out the latent exposure. Results:Among the sampled articles, sofa, paint of the balcony bars and baby powder had higher lead concentrations with 1741 mg/kg, 8700 mg/kg and more than 100000 mg/kg, respectively. But the two children had not yet bitten or licked the sofa and the bar painting was not peeling. But the children had been being rubbed baby powder by their parent since birth. Farther investigation revealed the lead in the powder came from red lead which was mixed intentionally. The blood lead levels of two children decreased rapidly after disuse of this baby powder. Conclusion:The portable XRF is an effective tool for searching the exposure source of pediatric lead poisoning in scene and can find out real cause for poisoning when integrated with questionnaire.%目的:掌握便携式X线荧光分析仪(XRF)用于铅中毒溯源调查的可行性.方法:在1家庭2幼儿铅中毒调查个案中,用XRF对其家庭内环境、食品、餐具、饮用水和儿童用品进行检测,寻找可疑铅暴露.结果:在抽查的27种物品中,铅含量较高的是皮沙发表面(1741 mg/kg)、阳台护栏油漆(8700 mg/kg)和散装无牌爽身粉(>100000 mg/kg),但两幼儿没有啃咬皮沙发的习惯,护栏油漆也没有破损脱落,两幼儿都有经常使用这种无牌散装爽身粉的习惯,经进一步调查爽身粉中的铅来自于配制中人为加入的红丹.病人脱离接触红丹爽身粉后血铅水平下降.结论:XRF是现场调查儿童铅中毒来源行之有效方法,结合问卷可快速找出暴露的原因.

  3. Diffractive X-Ray Telescopes

    Science.gov (United States)

    Skinner, Gerald K.

    2010-01-01

    Diffractive X-ray telescopes, using zone plates, phase Fresnel lenses, or related optical elements have the potential to provide astronomers with true imaging capability with resolution many orders of magnitude better than available in any other waveband. Lenses that would be relatively easy to fabricate could have an angular resolution of the order of micro-arc-seconds or even better, that would allow, for example, imaging of the distorted spacetime in the immediate vicinity of the super-massive black holes in the center of active galaxies. What then is precluding their immediate adoption? Extremely long focal lengths, very limited bandwidth, and difficulty stabilizing the image are the main problems. The history, and status of the development of such lenses is reviewed here and the prospects for managing the challenges that they present are discussed.

  4. Diffractive X-ray Telescopes

    CERN Document Server

    Skinner, Gerald K

    2010-01-01

    Diffractive X-ray telescopes using zone plates, phase Fresnel lenses, or related optical elements have the potential to provide astronomers with true imaging capability with resolution several orders of magnitude better than available in any other waveband. Lenses that would be relatively easy to fabricate could have an angular resolution of the order of micro-arc-seconds or even better, that would allow, for example, imaging of the distorted space- time in the immediate vicinity of the super-massive black holes in the center of active galaxies What then is precluding their immediate adoption? Extremely long focal lengths, very limited bandwidth, and difficulty stabilizing the image are the main problems. The history, and status of the development of such lenses is reviewed here and the prospects for managing the challenges that they present are discussed.

  5. An upgraded x-ray spectroscopy diagnostic on MST.

    Science.gov (United States)

    Clayton, D J; Almagri, A F; Burke, D R; Forest, C B; Goetz, J A; Kaufman, M C; O'Connell, R

    2010-10-01

    An upgraded x-ray spectroscopy diagnostic is used to measure the distribution of fast electrons in MST and to determine Z(eff) and the particle diffusion coefficient D(r). A radial array of 12 CdZnTe hard-x-ray detectors measures 10-150 keV Bremsstrahlung from fast electrons, a signature of reduced stochasticity and improved confinement in the plasma. A new Si soft-x-ray detector measures 2-10 keV Bremsstrahlung from thermal and fast electrons. The shaped output pulses from both detector types are digitized and the resulting waveforms are fit with Gaussians to resolve pileup and provide good time and energy resolution. Lead apertures prevent detector saturation and provide a well-known etendue, while lead shielding prevents pickup from stray x-rays. New Be vacuum windows transmit >2 keV x-rays, and additional Al and Be filters are sometimes used to reduce low energy flux for better resolution at higher energies. Measured spectra are compared to those predicted by the Fokker-Planck code CQL3D to deduce Z(eff) and D(r).

  6. 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.

  7. 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)

  8. Topological X-Rays and MRIs

    Science.gov (United States)

    Lynch, Mark

    2002-01-01

    Let K be a compact subset of the interior of the unit disk D in the plane and suppose one can't see through the boundary of D and identify K. However, assume that one can take "topological X-rays" of D which measure the "density" of K along the lines of the X-rays. By taking these X-rays from all directions, a "topological MRI" is generated for…

  9. Observation of femtosecond X-ray interactions with matter using an X-ray-X-ray pump-probe scheme.

    Science.gov (United States)

    Inoue, Ichiro; Inubushi, Yuichi; Sato, Takahiro; Tono, Kensuke; Katayama, Tetsuo; Kameshima, Takashi; Ogawa, Kanade; Togashi, Tadashi; Owada, Shigeki; Amemiya, Yoshiyuki; Tanaka, Takashi; Hara, Toru; Yabashi, Makina

    2016-02-01

    Resolution in the X-ray structure determination of noncrystalline samples has been limited to several tens of nanometers, because deep X-ray irradiation required for enhanced resolution causes radiation damage to samples. However, theoretical studies predict that the femtosecond (fs) durations of X-ray free-electron laser (XFEL) pulses make it possible to record scattering signals before the initiation of X-ray damage processes; thus, an ultraintense X-ray beam can be used beyond the conventional limit of radiation dose. Here, we verify this scenario by directly observing femtosecond X-ray damage processes in diamond irradiated with extraordinarily intense (∼10(19) W/cm(2)) XFEL pulses. An X-ray pump-probe diffraction scheme was developed in this study; tightly focused double-5-fs XFEL pulses with time separations ranging from sub-fs to 80 fs were used to excite (i.e., pump) the diamond and characterize (i.e., probe) the temporal changes of the crystalline structures through Bragg reflection. It was found that the pump and probe diffraction intensities remain almost constant for shorter time separations of the double pulse, whereas the probe diffraction intensities decreased after 20 fs following pump pulse irradiation due to the X-ray-induced atomic displacement. This result indicates that sub-10-fs XFEL pulses enable conductions of damageless structural determinations and supports the validity of the theoretical predictions of ultraintense X-ray-matter interactions. The X-ray pump-probe scheme demonstrated here would be effective for understanding ultraintense X-ray-matter interactions, which will greatly stimulate advanced XFEL applications, such as atomic structure determination of a single molecule and generation of exotic matters with high energy densities.

  10. The efficacy of x-ray pelvimetry

    Energy Technology Data Exchange (ETDEWEB)

    Barton, J.J. (Univ. of Illinois, Chicago); Garbaciak, J.A. Jr.; Ryan, G.M., Jr.

    1982-06-01

    Comparison is made of x-ray pelvimetry use on a public and private service in 1974 with experience in 1979, when the clinic service did no x-ray pelvimetry while the private service continued as before. It is concluded that the use of x-ray pelvimetry is inadequate as a predictor of cesarean section because of cephalopelvic disproportion, does not improve neonatal mortality, and poses potential hazards to the mother and fetus. Its use in the management of breech presentations is not currently established by our data. Guidelines are presented for the management of patients in labor without using x-ray pelvimetry.

  11. 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

  12. An Imaging X-Ray Polarimetry Mission

    Science.gov (United States)

    Weisskopf, Martin C.; Bellazini, Ronaldo; Costa, Enrico; Ramsey, Brian; O'Dell, Steve; Elsner, Ronald; Pavlov, George; Matt, Giorgio; Kaspi, Victoria; Tennant, Allyn; Coppi, Paolo; Wu, Kinwah; Siegmund, Oswald

    2008-01-01

    Technical progress both in x-ray optics and in polarization-sensitive x-ray detectors, which our groups have pioneered, enables a scientifically powerful---yet inexpensive---dedicated mission for imaging x-ray polarimetry. Such a mission is sufficiently sensitive to measure x-ray (linear) polarization for a broad range of cosmic sources --particularly those involving neutron stars, stellar black holes, and supermassive black holes (active galactic nuclei). We describe the technical elements, discuss a mission concept, and synopsize the important physical and astrophysical questions such a mission would address.

  13. Low Energy X-Ray Diagnostics - 1981.

    Science.gov (United States)

    1981-01-01

    appreciable back- [25] G. L. Johnson and R. F. Wuerker, X - RayO cs and ground at the diffraction line. It is for this reason X -Ray Microanalysis (Academic...I A-0AIIG 93 AWERICAN INST OF PHYSICS NEW YORK F/6 14/2 LOW ENERGY X -RAY DIAGNOSTICS - 1981.(U) 1961 D T ATTWOOO. 8 L HENKE AFOSAt-?SSA-61-00ORZN...RESOLUTION TEST CHART NATIONAl RJRAL AU M ’IAN[I)ARDS I ,* A Focusing, Filtering, and Scattering of V. Rehn Soft X -Rays by Mirrors 162 Synthetic

  14. 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).

  15. Symbiotic Stars in X-rays

    Science.gov (United States)

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

    2014-01-01

    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 9 white dwarf symbiotics that were not previously known to be X-ray sources and one that was previously detected as a supersoft X-ray source. The 9 new X-ray detections were the result of a survey of 41 symbiotic stars, and they increase the number of symbiotic stars known to be X-ray sources by approximately 30%. Swift/XRT detected all of the new X-ray sources at energies greater than 2 keV. Their X-ray spectra are consistent with thermal emission and fall naturally into three distinct groups. The first group contains those sources with a single, highly absorbed hard component, which we identify as probably coming from an accretion-disk boundary layer. The second group is composed of those sources with a single, soft X-ray spectral component, which likely arises in a region where low-velocity shocks produce X-ray emission, i.e. a colliding-wind region. The third group consists of those sources with both hard and soft X-ray spectral components. We also find that unlike in the optical, where rapid, stochastic brightness variations from the accretion disk typically are not seen, detectable UV flickering is a common property of symbiotic stars. Supporting our physical interpretation of the two X-ray spectral components, simultaneous Swift UV photometry shows that symbiotic stars with harder X-ray emission tend to have stronger UV flickering, which is usually associated with accretion through a disk. To place these new observations in the context of previous work on X-ray emission from symbiotic stars, we modified and extended the alpha/beta/gamma classification scheme for symbiotic-star X-ray spectra that was introduced by Muerset et al. based upon observations with the ROSAT satellite, to include a new sigma classification for sources with

  16. X-rays from the youngest stars

    Science.gov (United States)

    Feigelson, Eric D.

    1994-01-01

    The X-ray properties of classical and weak-lined T Tauri stars are briefly reviewed, emphasizing recent results from the ROSAT satellite and prospects for ASCA. The interpretation of the high level of T Tauri X-rays as enhanced solar-type magnetic activity is discussed and criticized. The census of X-ray emitters is significantly increasing estimates of galactic star formation efficiency, and X-ray emission may be important for self-regulation of star formation. ASCA images will detect star formation regions out to several kiloparsecs and will study the magnetically heated plasma around T Tauri stars. However, images will often suffer from crowding effects.

  17. The History of X-ray Free-Electron Lasers

    Energy Technology Data Exchange (ETDEWEB)

    Pellegrini, C.; /UCLA /SLAC

    2012-06-28

    The successful lasing at the SLAC National Accelerator Laboratory of the Linear Coherent Light Source (LCLS), the first X-ray free-electron laser (X-ray FEL), in the wavelength range 1.5 to 15 {angstrom}, pulse duration of 60 to few femtoseconds, number of coherent photons per pulse from 10{sup 13} to 10{sup 11}, is a landmark event in the development of coherent electromagnetic radiation sources. Until now electrons traversing an undulator magnet in a synchrotron radiation storage ring provided the best X-ray sources. The LCLS has set a new standard, with a peak X-ray brightness higher by ten orders of magnitudes and pulse duration shorter by three orders of magnitudes. LCLS opens a new window in the exploration of matter at the atomic and molecular scales of length and time. Taking a motion picture of chemical processes in a few femtoseconds or less, unraveling the structure and dynamics of complex molecular systems, like proteins, are some of the exciting experiments made possible by LCLS and the other X-ray FELs now being built in Europe and Asia. In this paper, we describe the history of the many theoretical, experimental and technological discoveries and innovations, starting from the 1960s and 1970s, leading to the development of LCLS.

  18. Hard x-ray imaging polarimeter for PolariS

    Science.gov (United States)

    Hayashida, Kiyoshi; Kim, Juyong; Sadamoto, Masaaki; Yoshinaga, Keigo; Gunji, Shuichi; Mihara, Tatehiro; Kishimoto, Yuji; Kubo, Hidetoshi; Mizuno, Tsunefumi; Takahashi, Hiromitsu; Dotani, Tadayasu; Yonetoku, Daisuke; Nakamori, Takeshi; Yoneyama, Tomokage; Ikeyama, Yuki; Kamitsukasa, Fumiyoshi

    2016-07-01

    Hard X-ray imaging polarimeters are developed for the X-ray γ-ray polaeimtery satellite PolariS. The imaging polarimter is scattering type, in which anisotropy in the direction of Compton scattering is employed to measure the hard X-ray (10-80 keV) polarization, and is installed on the focal planes of hard X-ray telescopes. We have updated the design of the model so as to cover larger solid angles of scattering direction. We also examine the event selection algorithm to optimize the detection efficiency of recoiled electrons in plastic scintillators. We succeed in improving the efficiency by factor of about 3-4 from the previous algorithm and criteria for 18-30 keV incidence. For 23 keV X-ray incidence, the recoiled electron energy is about 1 keV. We measured the efficiency to detect recoiled electrons in this case, and found about half of the theoretical limit. The improvement in this efficiency directly leads to that in the detection efficiency. In other words, however, there is still a room for improvement. We examine various process in the detector, and estimate the major loss is primarily that of scintillation light in a plastic scintillator pillar with a very small cross section (2.68mm squared) and a long length (40mm). Nevertheless, the current model provides the MDP of 6% for 10mCrab sources, which are the targets of PolariS.

  19. Bragg x-ray survey spectrometer for ITER.

    Science.gov (United States)

    Varshney, S K; Barnsley, R; O'Mullane, M G; Jakhar, S

    2012-10-01

    Several potential impurity ions in the ITER plasmas will lead to loss of confined energy through line and continuum emission. For real time monitoring of impurities, a seven channel Bragg x-ray spectrometer (XRCS survey) is considered. This paper presents design and analysis of the spectrometer, including x-ray tracing by the Shadow-XOP code, sensitivity calculations for reference H-mode plasma and neutronics assessment. The XRCS survey performance analysis shows that the ITER measurement requirements of impurity monitoring in 10 ms integration time at the minimum levels for low-Z to high-Z impurity ions can largely be met.

  20. A hard X-ray laboratory for monochromator characterisation

    Energy Technology Data Exchange (ETDEWEB)

    Hamelin, B. [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France)

    1997-04-01

    Since their installation at ILL during the 1970`s the ILL {gamma}-ray diffractometers have been intensively used in the development of neutron monochromators. However, the ageing of the sources and new developments in hard X-ray diffractometry lead to a decision at the end of 1995 to replace the existing {gamma}-ray laboratory with a hard X-ray laboratory, based on a 420 keV generator, making available in the long term several beam-lines for rapid characterisation of monochromator crystals. The facility is now installed and its characteristics and advantages are outlined. (author). 2 refs.

  1. Precision X-ray measurements on kaonic atoms at LNF

    CERN Document Server

    Marton, J

    2007-01-01

    After the successfully performed DEAR experiment at DAFNE - resulting in the most precise data on the hadronic shift and width in kaonic hydrogen up-to-now - the next step will be the measurement at the percent level using new X-ray detectors. These detectors (silicon drift detectors) are developed within the SIDDHARTA project. The asynchronous background will be suppressed using the time correlation between the kaon and the X-ray by 2-3 orders of magnitude. These measurements will lead to precise values of the isospin-dependent antikaon-nucleon scattering lengths, thus opening a new insight in the low-energy kaon nucleon interaction.

  2. Precision X-ray measurements on kaonic atoms at LNF

    OpenAIRE

    Marton, J.

    2007-01-01

    After the successfully performed DEAR experiment at DAFNE - resulting in the most precise data on the hadronic shift and width in kaonic hydrogen up-to-now - the next step will be the measurement at the percent level using new X-ray detectors. These detectors (silicon drift detectors) are developed within the SIDDHARTA project. The asynchronous background will be suppressed using the time correlation between the kaon and the X-ray by 2-3 orders of magnitude. These measurements will lead to pr...

  3. 改进型M-P神经网络在能量色散X荧光分析测定铅锌矿元素含量的应用研究%Research on the Application of Improved M-P Neural Network to the Determination of Lead and Zinc Ore Element Contents by Energy Disperse X-Ray Fluorescence Analysis

    Institute of Scientific and Technical Information of China (English)

    李飞; 葛良全; 张庆贤; 谷懿; 万志雄; 李王燕

    2012-01-01

    以新疆西天山铅锌矿样品的Cu,Fe,Pb等元素X荧光测量数据做训练样本,McCulloch-Pitts神经网络(M-P神经网络)为基础,基体效应为依据,建立新的神经网络模型对Zn进行定量预测.结果预测值与测量值的相对误差在<5%.此方法可较准确,快速的应用于现场X荧光测定,为X荧光光谱信息修正提供一种新方法.%Because of different constraints (such as different kinds of measurable elements, characteristic X-ray energy, changes in matrix composition, etc ), usually it's not easy to get accurate information of elements, resulting in mistakes in later data analysis of energy disperse X-ray fluorescence measurement The method is based on McCulloch-Pitts neural network (M-P neural network), according to matrix effect, to establish a new neural network model for quantitative forecasting of Zn by taking the data of X-ray fluorescence measurements of Cu, Fe, Pb, etc in lead-zinc mine in western Tianshan as the training sample. The relative error between predicted value and measured value is less than 5%. This method can be more accurate and rapid for X-ray fluorescence; it provides a new approach to correcting information of X-ray fluorescence.

  4. X-ray simulation algorithms used in ISP

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, John P. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-07-29

    ISP is a simulation code which is sometimes used in the USNDS program. ISP is maintained by Sandia National Lab. However, the X-ray simulation algorithm used by ISP was written by scientists at LANL – mainly by Ed Fenimore with some contributions from John Sullivan and George Neuschaefer and probably others. In email to John Sullivan on July 25, 2016, Jill Rivera, ISP project lead, said “ISP uses the function xdosemeters_sim from the xgen library.” The is a fortran subroutine which is also used to simulate the X-ray response in consim (a descendant of xgen). Therefore, no separate documentation of the X-ray simulation algorithms in ISP have been written – the documentation for the consim simulation can be used.

  5. Synchrotron X-ray induced solution precipitation of nanoparticles

    CERN Document Server

    Lee, H J; Hwu, Y; Tsai, W L

    2003-01-01

    By irradiating a solution in electroless Ni deposition using synchrotron X-rays, Ni composite was found to nucleate homogeneously and eventually precipitate in the form of nanoparticles. The size of the nanoparticles precipitated is rather uniform (100-300 nm depending on the applied temperature). By the addition of an organic acid, well-dispersed nanoparticles could be effectively deposited on glass substrate. The hydrated electrons (e sub a sub q sup -), products of radiolysis of water molecules by synchrotron X-rays, may be responsible for the effective reduction of the metal ions, resulting in homogeneous nucleation and nanoparticle formation. Our results suggest that synchrotron X-ray can be used to induce solution precipitation of nanoparticles and therefore lead to a new method of producing nanostructured particles and coating.

  6. Soft X ray properties of the Geminga pulsar

    Science.gov (United States)

    Halpern, J. P.; Ruderman, M.

    1993-01-01

    The ROSAT soft x ray spectrum and pulse profile of the Geminga pulsar are analyzed and interpreted in terms of thermal emission from the surface of the neutron star. The x ray spectrum appears to consist of two blackbody components with T1 = (5.2 +/- 1.0) x 10 5 K and T2 approximately 3 x 106 K, respectively. The inferred ratio of surface areas, A2/A1, is approximately 3 x 10-5. Both components are highly modulated at the pulsar rotation period, but the harder x ray pulse is narrower, and leads the main (soft) x ray pulse by about 105 deg of phase. The soft x ray component is interpreted as photospheric cooling of much of the neutron star's surface area, while the small, hot region could be part of the much smaller polar cap heated by energetic particles flowing inward from the magnetospheric accelerator which is responsible for the production of Geminga's gamma rays. Geminga's gamma ray emission is consistent with outer-magnetosphere accelerator models for highly inclined dipoles. These predict the beaming of energetic gamma rays close enough to the star to give copious e(+/-) production in the stellar magnetic field and a large circumstellar pair density from pair inflow toward the surface. These pairs may quench radio emission, and also reflect most of the hard polar cap x rays back to the stellar surface by cyclotron resonance scattering. They are then reemitted from that much larger area at the lower temperature T1. The single-peaked nature of the x ray pulse and its energy-dependent phase suggest an off-center dipole geometry for the surface magnetic field. Under the assumption that the soft x ray emission comes from the full surface of a neutron star of radius R = 10 km, a distance estimate of (150-400) pc is derived. This range is consistent with the fit interstellar column density of (1.5 +/- 0.5) x 1020 cm-2. Distances less than 150 pc are probably ruled out both by the lower limit on the column density, and also by the requirement that the Rayleigh

  7. X-ray computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kalender, Willi A [Institute of Medical Physics, University Erlangen-Nuernberg, Henkestr. 91, D-91052 Erlangen (Germany)

    2006-07-07

    X-ray computed tomography (CT), introduced into clinical practice in 1972, was the first of the modern slice-imaging modalities. To reconstruct images mathematically from measured data and to display and to archive them in digital form was a novelty then and is commonplace today. CT has shown a steady upward trend with respect to technology, performance and clinical use independent of predictions and expert assessments which forecast in the 1980s that it would be completely replaced by magnetic resonance imaging. CT not only survived but exhibited a true renaissance due to the introduction of spiral scanning which meant the transition from slice-by-slice imaging to true volume imaging. Complemented by the introduction of array detector technology in the 1990s, CT today allows imaging of whole organs or the whole body in 5 to 20 s with sub-millimetre isotropic resolution. This review of CT will proceed in chronological order focussing on technology, image quality and clinical applications. In its final part it will also briefly allude to novel uses of CT such as dual-source CT, C-arm flat-panel-detector CT and micro-CT. At present CT possibly exhibits a higher innovation rate than ever before. In consequence the topical and most recent developments will receive the greatest attention. (review)

  8. SMM X-ray polychromator

    Science.gov (United States)

    Strong, Keith T.; Haisch, Bernhard M. (Compiler); Lemen, James R. (Compiler); Acton, L. W.; Bawa, H. S.; Claflin, E. S.; Freeland, S. L.; Slater, G. L.; Kemp, D. L.; Linford, G. A.

    1988-01-01

    The range of observing and analysis programs accomplished with the X-Ray Polychromator (XRP) instruments during the decline of solar cycle 21 and the rise of the solar cycle 22 is summarized. Section 2 describes XRP operations and current status. This is meant as a guide on how the instrument is used to obtain data and what its capabilities are for potential users. The science section contains a series of representative abstracts from recently published papers on major XRP science topics. It is not meant to be a complete list but illustrates the type of science that can come from the analysis of the XRP data. There then follows a series of appendixes that summarize the major data bases that are available. Appendix A is a complete bibliography of papers and presentations produced using XRP data. Appendix B lists all the spectroscopic data accumulated by the Flat Crystal Spectrometer (FCS). Appendix C is a compilation of the XRP flare catalogue for events equivalent to a GOES C-level flare or greater. It lists the start, peak and end times as well as the peak Ca XIX flux.

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

    Science.gov (United States)

    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.

  10. Multilayer on-chip stacked Fresnel zone plates: Hard x-ray fabrication and soft x-ray simulations

    Energy Technology Data Exchange (ETDEWEB)

    Li, Kenan; Wojcik, Michael J.; Ocola, Leonidas E.; Divan, Ralu; Jacobsen, Chris

    2015-11-01

    Fresnel zone plates are widely used as x-ray nanofocusing optics. To achieve high spatial resolution combined with good focusing efficiency, high aspect ratio nanolithography is required, and one way to achieve that is through multiple e-beam lithography writing steps to achieve on-chip stacking. A two-step writing process producing 50 nm finest zone width at a zone thickness of 1.14 µm for possible hard x-ray applications is shown here. The authors also consider in simulations the case of soft x-ray focusing where the zone thickness might exceed the depth of focus. In this case, the authors compare on-chip stacking with, and without, adjustment of zone positions and show that the offset zones lead to improved focusing efficiency. The simulations were carried out using a multislice propagation method employing Hankel transforms.

  11. X-raying clumped stellar winds

    CERN Document Server

    Oskinova, L M; Feldmeier, A

    2008-01-01

    X-ray spectroscopy is a sensitive probe of stellar winds. X-rays originate from optically thin shock-heated plasma deep inside the wind and propagate outwards throughout absorbing cool material. Recent analyses of the line ratios from He-like ions in the X-ray spectra of O-stars highlighted problems with this general paradigm: the measured line ratios of highest ions are consistent with the location of the hottest X-ray emitting plasma very close to the base of the wind, perhaps indicating the presence of a corona, while measurements from lower ions conform with the wind-embedded shock model. Generally, to correctly model the emerging X-ray spectra, a detailed knowledge of the cool wind opacities based on stellar atmosphere models is prerequisite. A nearly grey stellar wind opacity for the X-rays is deduced from the analyses of high-resolution X-ray spectra. This indicates that the stellar winds are strongly clumped. Furthermore, the nearly symmetric shape of X-ray emission line profiles can be explained if t...

  12. 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…

  13. X-ray lasers: Multicolour emission

    Science.gov (United States)

    Feng, Chao; Deng, Haixiao

    2016-11-01

    The X-ray free-electron laser at the SLAC National Accelerator Laboratory in the US can now generate multicolour X-ray pulses with unprecedented brightness using the fresh-slice technique. The development opens the way to new forms of spectroscopy.

  14. New Insights into X-ray Binaries

    CERN Document Server

    Casares, Jorge

    2009-01-01

    X-ray binaries are excellent laboratories to study collapsed objects. On the one hand, transient X-ray binaries contain the best examples of stellar-mass black holes while persistent X-ray binaries mostly harbour accreting neutron stars. The determination of stellar masses in persistent X-ray binaries is usually hampered by the overwhelming luminosity of the X-ray heated accretion disc. However, the discovery of high-excitation emission lines from the irradiated companion star has opened new routes in the study of compact objects. This paper presents novel techniques which exploits these irradiated lines and summarises the dynamical masses obtained for the two populations of collapsed stars: neutron stars and black holes.

  15. X-ray Fourier ptychographic microscopy

    CERN Document Server

    Simons, H; Guigay, J P; Detlefs, C

    2016-01-01

    Following the recent developement of Fourier ptychographic microscopy (FPM) in the visible range by Zheng et al. (2013), we propose an adaptation for hard x-rays. FPM employs ptychographic reconstruction to merge a series of low-resolution, wide field of view images into a high-resolution image. In the x-ray range this opens the possibility to overcome the limited numerical aperture of existing x-ray lenses. Furthermore, digital wave front correction (DWC) may be used to charaterize and correct lens imperfections. Given the diffraction limit achievable with x-ray lenses (below 100 nm), x-ray Fourier ptychographic microscopy (XFPM) should be able to reach resolutions in the 10 nm range.

  16. X-ray diffraction: instrumentation and applications.

    Science.gov (United States)

    Bunaciu, Andrei A; Udriştioiu, Elena Gabriela; Aboul-Enein, Hassan Y

    2015-01-01

    X-ray diffraction (XRD) is a powerful nondestructive technique for characterizing crystalline materials. It provides information on structures, phases, preferred crystal orientations (texture), and other structural parameters, such as average grain size, crystallinity, strain, and crystal defects. X-ray diffraction peaks are produced by constructive interference of a monochromatic beam of X-rays scattered at specific angles from each set of lattice planes in a sample. The peak intensities are determined by the distribution of atoms within the lattice. Consequently, the X-ray diffraction pattern is the fingerprint of periodic atomic arrangements in a given material. This review summarizes the scientific trends associated with the rapid development of the technique of X-ray diffraction over the past five years pertaining to the fields of pharmaceuticals, forensic science, geological applications, microelectronics, and glass manufacturing, as well as in corrosion analysis.

  17. LOBSTER - New Space X-Ray telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Hudec, R. [Astronomical Institute, Academy of Sciences of the Czech Republic, CZ-251 65 Ondrejov (Czech Republic); Pina, L. [Faculty of Nuclear Science, Czech Technical University, Prague (Czech Republic); Simon, V. [Astronomical Institute, Academy of Sciences of the Czech Republic, CZ-251 65 Ondrejov (Czech Republic); Sveda, L. [Faculty of Nuclear Science, Czech Technical University, Prague (Czech Republic); Inneman, A.; Semencova, V. [Center for Advanced X-ray Technologies, Reflex, Prague (Czech Republic); Skulinova, M. [Astronomical Institute, Academy of Sciences of the Czech Republic, CZ-251 65 Ondrejov (Czech Republic)

    2007-04-15

    We discuss the technological and scientific aspects of fully innovative very wide-field X-ray telescopes with high sensitivity. The prototypes of Lobster telescopes designed, developed and tested are very promising, allowing the proposals for space projects with very wide-field Lobster Eye X-ray optics to be considered for the first time. The novel telescopes will monitor the sky with unprecedented sensitivity and angular resolution of order of 1 arcmin. They are expected to contribute essentially to study of various astrophysical objects such as AGN, SNe, Gamma-ray bursts (GRBs), X-ray flashes (XRFs), galactic binary sources, stars, CVs, X-ray novae, various transient sources, etc. For example, the Lobster optics based X-ray All Sky Monitor is capable to detect around 20 GRBs and 8 XRFs yearly and this will surely significantly contribute to the related science.

  18. Globular Cluster X-ray Sources

    CERN Document Server

    Verbunt, F

    2004-01-01

    After a brief historical overview we discuss the luminous X-ray sources in globular clusters of our Galaxy. This is followed by an overview of the very luminous X-ray sources studied in globular clusters of 14 other galaxies, and a discussion of their formation and the relation to X-ray sources outside globular clusters. We describe the discovery and classification of low-luminosity X-ray sources, and end the review with some remarks on the formation and evolution of X-ray sources in globular clusters. Observational results are summarized in three tables. Comments are very welcome. Please send them to F.W.M.Verbunt@astro.uu.nl and lewin@mit.edu.

  19. X-Rays from Green Pea Analogs

    Science.gov (United States)

    Brorby, Matthew

    2014-09-01

    X-rays may have contributed to the heating and reionization of the IGM in the early universe. High mass X-ray binaries (HMXB) within small, low-metallicity galaxies are expected to be the main source of X-rays at this time. Since studying these high-redshift galaxies is currently impossible, we turn to local analogs that have the same properties the galaxies in the early are expected to have. A number of recent studies have shown an enhanced number of HMXBs in nearby low metallicity galaxies. We propose to observe a sample of metal-deficient luminous compact galaxies (LCG) in order to determine if the X-ray luminosity is enhanced relative to SFR, thereby providing further evidence to the importance of X-rays in the early universe.

  20. An X-ray view of quasars

    CERN Document Server

    Singh, K P

    2013-01-01

    I present an overview of observational studies of quasars of all types, with particular emphasis on X-ray observational studies. The presentation is based on the most popularly accepted unified picture of quasars - collectively referred to as AGN (active galactic nuclei) in this review. Characteristics of X-ray spectra and X-ray variability obtained from various X-ray satellites over the last 5 decades have been presented and discussed. The contribution of AGN in understanding the cosmic X-ray background is discussed very briefly. Attempt has been made to provide up-to-date information; however, this is a vast subject and this presentation is not intended to be comprehensive.

  1. Synchrotron x-ray ultrafast x-ray imaging on dynamic multiphase flow studies

    Science.gov (United States)

    Wang, Yujie; Fezzaa, Kamel; Wang, Jin; Im, Kyoung-Su

    2007-03-01

    To overcome the long-exposure time of x-ray imaging for liquid systems. In the past year, we have developed the first ultrafast white-beam synchrotron x-ray phase-contrast imaging technique in the world. With its unprecedented temporal (0.5 μs) and spatial resolutions (1 μm), this new technique has already shown great promises in the study of complex fluid mechanical systems. It can probe complex surface morphology and transient dynamics of these interfaces of fluid mechanical systems without the nuisance of multiple scattering. This technique is a big step forward in comparison to millisecond-temporal and micrometer-spatial imaging resolutions normally achieved at various synchrotron sources. With the development of this new technique, we can already carry out research in fluid mechanical systems in competition with world-leading research groups. Our study of the primary breakup process of a coaxial air-assisted liquid jet revealed that the dynamics is dominated by a ``liquid membrane breakup'' process instead of a simple ``ligament mediated breakup'' process owing to our far superior temporal and spatial resolutions. This observation will naturally lead to a cascade idea for the unified treatment of liquid jets, droplets, and liquid membranes breakup mechanism.

  2. Stacked, filtered multi-channel X-ray diode array

    Science.gov (United States)

    MacNeil, L. P.; Dutra, E. C.; Compton, S. M.; Jacoby, B. A.; Raphaelian, M. L.

    2015-08-01

    There are many types of X-ray diodes that are used for X-ray flux or spectroscopic measurements and for estimating the spectral shape of the VUV to soft X-ray spectrum. However, a need arose for a low cost, robust X-ray diode to use for experiments in hostile environments on multiple platforms, and for experiments that utilize forces that may destroy the diode(s). Since the typical proposed use required a small size with a minimal single line-of-sight, a parallel array could not be used. So, a stacked, filtered multi-channel X-ray diode array was developed, called the MiniXRD. To achieve significant cost savings while maintaining robustness and ease of field setup, repair, and replacement, we designed the system to be modular. The filters were manufactured in-house and cover the range from 450 eV to 5000 eV. To achieve the line-of-sight accuracy needed, we developed mounts and laser alignment techniques. We modeled and tested elements of the diode design at NSTec Livermore Operations (NSTec / LO) to determine temporal response and dynamic range, leading to diode shape and circuitry changes to optimize impedance and charge storage. We fielded individual and stacked systems at several national facilities as ancillary `ride-along' diagnostics to test and improve the design usability. We present the MiniXRD system performance which supports consideration as a viable low-cost alternative for multiple-channel low-energy X-ray measurements. This diode array is currently at Technical Readiness Level (TRL) 6.

  3. Stacked, filtered multi-channel X-ray diode array

    Energy Technology Data Exchange (ETDEWEB)

    MacNeil, Lawrence [National Security Technologies, LLC. (NSTec), Mercury, NV (United States); Dutra, Eric [National Security Technologies, LLC. (NSTec), Mercury, NV (United States); Raphaelian, Mark [National Security Technologies, LLC. (NSTec), Mercury, NV (United States); Compton, Steve [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Jacoby, Barry [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-08-01

    There are many types of X-ray diodes used for X-ray flux or spectroscopic measurements and for estimating the spectral shape of the VUV to soft X-ray spectrum. However, a need exists for a low-cost, robust X-ray diode to use for experiments in hostile environments on multiple platforms, and for experiments that utilize forces that may destroy the diode(s). Since the typical proposed use required a small size with a minimal single line-of-sight, a parallel array could not be used. So, a stacked, filtered multi-channel X-ray diode array was developed, called the MiniXRD. To achieve significant cost savings while maintaining robustness and ease of field setup, repair, and replacement, we designed the system to be modular. The filters were manufactured in-house and cover the range from 450 eV to 5000 eV. To achieve the line-of-sight accuracy needed, we developed mounts and laser alignment techniques. We modeled and tested elements of the diode design at NSTec Livermore Operations (NSTec / LO) to determine temporal response and dynamic range, leading to diode shape and circuitry changes to optimize impedance and charge storage. The authors fielded individual and stacked systems at several national facilities as ancillary "ride-along" diagnostics to test and improve the design usability. This paper presents the MiniXRD system performance, which supports consideration as a viable low-costalternative for multiple-channel low-energy X-ray measurements. This diode array is currently at Technical Readiness Level (TRL) 6.

  4. 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.

  5. X-Ray Background from Early Binaries

    Science.gov (United States)

    Kohler, Susanna

    2016-11-01

    What impact did X-rays from the first binary star systems have on the universe around them? A new study suggests this radiation may have played an important role during the reionization of our universe.Ionizing the UniverseDuring the period of reionization, the universe reverted from being neutral (as it was during recombination, the previous period)to once again being ionized plasma a state it has remained in since then. This transition, which occurred between 150 million and one billion years after the Big Bang (redshift of 6 z 20), was caused by the formation of the first objects energetic enough to reionize the universes neutral hydrogen.ROSAT image of the soft X-ray background throughout the universe. The different colors represent different energy bands: 0.25 keV (red), 0.75 keV (green), 1.5 keV (blue). [NASA/ROSAT Project]Understanding this time period in particular, determining what sources caused the reionization, and what the properties were of the gas strewn throughout the universe during this time is necessary for us to be able to correctly interpret cosmological observations.Conveniently, the universe has provided us with an interesting clue: the large-scale, diffuse X-ray background we observe all around us. What produced these X-rays, and what impact did this radiation have on the intergalactic medium long ago?The First BinariesA team of scientists led by Hao Xu (UC San Diego) has suggested that the very first generation of stars might be an important contributor to these X-rays.This hypothetical first generation, Population III stars, are thought to have formed before and during reionization from large clouds of gas containing virtually no metals. Studies suggest that a large fraction of Pop III stars formed in binaries and when those stars ended their lives as black holes, ensuing accretion from their companions could produceX-ray radiation.The evolution with redshift of the mean X-ray background intensities. Each curve represents a different

  6. X-ray in Zeta-Ori

    Science.gov (United States)

    López-García, M. A.; López-Santiago, J. L.; Albacete-Colombo, J. F.; De Castro, E.

    2013-05-01

    Nearby star-forming regions are ideal laboratories to study high-energy emission processes but they usually present high absorption what makes difficult to detect the stellar population inside the molecular complex. As young late-type stars show high X-ray emission and X-ray photons are little absorbed by interstellar material, X-ray dedicated surveys are an excellent tool to detect the low-mass stellar population in optically absorbed regions. In this work, we present a study of the star-forming region Zeta-Ori and its surroundings. We combine optical, infrared and X-ray data. Properties of the X-ray emiting plasma and infrared features of the young stellar objects detected in the XMM-Newton observation are determined. The southern part of the Orion B giant molecular cloud complex harbor other star forming regions, as NGC 2023 and NGC 2024, we use this regions to compare. We study the spectral energy distribution of X-ray sources. Combining these results with infrared, the X-ray sources are classified as class I, class II and class III objects. The X-ray spectrum and ligth curve of detected X-ray sources is analyzed to found flares. We use a extincion-independent index to select the stars with circumstellar disk, and study the relationship between the present of disk and the flare energy. The results are similar to others studies and we conclude that the coronal properties of class II and class III objects in this region do not differ significantly from each other and from stars of similar infrared class in the ONC.

  7. X-ray Scattered Halo around IGR J17544-2619

    CERN Document Server

    Mao, Junjie; Zhang, Shuang-Nan

    2014-01-01

    X-ray photons coming from an X-ray point source not only arrive at the detector directly, but also can be strongly forward-scattered by the interstellar dust along the line of sight (LOS), leading to a detectable diffuse halo around the X-ray point source. The geometry of small angle X-ray scattering is straightforward, namely, the scattered photons travel longer paths and thus arrive later than the unscattered ones; thus the delay time of X-ray scattered halo photons can reveal information of the distances of the interstellar dust and the point source. Here we present a study of the X-ray scattered around IGR J17544-2619, which is one of the so-called supergiant fast X-ray transients. IGR J17544-2619 underwent a striking outburst when observed with Chandra on 2004 July 3, providing a near delta-function lightcurve. We find that the X-ray scattered halo around IGR J17544-2619 is produced by two interstellar dust clouds along the LOS. The one which is closer to the observer gives the X-ray scattered at larger ...

  8. 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

  9. Soft X-Ray Laser Development

    Science.gov (United States)

    1989-10-01

    AND SUBTrI 5. FUNDING NUMBERS Soft X-ray Laser Development 61102F/2301/A8 L AUTHOR(S) ( Szymon Suckewer 7. PERFORMING ORGANIZATION NAME(S) AND ADORESS...REPORT Report of Progress on Soft X-ray Laser Development submitted to Air Force Office of Scientific Research by Acession For DT!C T.IB Princeton...x-ray laser development by Jaegl6 and coworkers 6, however the present work on aluminium plasmas pumped with a low energy Nd laser was primarily

  10. 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.

  11. X-ray phase-contrast methods

    Energy Technology Data Exchange (ETDEWEB)

    Lider, V. V., E-mail: lider@ns.crys.ras.ru; Kovalchuk, M. V. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation)

    2013-11-15

    This review is devoted to a comparative description of the methods for forming X-ray phase-contrast images of weakly absorbing (phase) objects. These include the crystal interferometer method, the Talbot interferometer method, diffraction-enhanced X-ray imaging, and the in-line method. The potential of their practical application in various fields of science and technology is discussed. The publications on the development and optimization of X-ray phase-contrast methods and the experimental study of phase objects are analyzed.

  12. X-rays from Alpha Centauri

    Science.gov (United States)

    Nugent, J.; Garmire, G.

    1978-01-01

    HEAO 1 observations of soft X-ray emission from a point source in the vicinity of Alpha Cen are reported. The source, designated H1437-61, is tentatively identified with Alpha Cen, and an X-ray luminosity comparable to that of the sun in an active state is estimated. A temperature of about 500,000 K and an emission integral of 5 x 10 to the 50th per cu cm are obtained. Coronal emission is suggested as the X-ray-producing mechanism.

  13. Speckle Scanning Based X-ray Imaging

    CERN Document Server

    Berujon, Sebastien

    2015-01-01

    The X-ray near field speckle scanning concept is an approach recently introduced to obtain absorption, phase and darkfield images of a sample. In this paper, we demonstrate ways of recovering from a sample its ultra-small angle X-ray scattering distribution using numerical deconvolution, and the 2D phase gradient signal from random step scans, the latter being used to elude the flat field correction error. Each feature is explained theoretically and demonstrated experimentally at a synchrotron X-ray facility.

  14. Optics for coherent X-ray applications

    OpenAIRE

    2014-01-01

    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 w...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-07-01

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

  16. The Study of Selecting Sample Detecting Position and Lead Plate Inner Material in Thin Film Method X-Ray Fluorescence Measurement%薄膜法X射线荧光测量中样品检测位置及防护铅板内衬材料的选择研究

    Institute of Scientific and Technical Information of China (English)

    甘婷婷; 张玉钧; 赵南京; 殷高方; 董欣欣; 王亚萍; 刘建国; 刘文清

    2015-01-01

    (1)以型号316不锈钢金属板为研究对象,对薄膜法X射线荧光光谱测量中,样品检测位置的选择进行研究,确定了最佳的样品检测位置为样品距离X射线管和探测器水平基线1 cm处,并且与X射线管和探测器水平基线成16°角度。(2)以工业环境空气重金属污染物Pb ,Cd ,Cr为主要分析对象,在有铅板防护情况下进行薄膜法X射线荧光光谱测量研究,发现X射线会穿透样品薄膜而继续激发防护铅板,使得滤膜背景光谱中有较强的铅谱线干扰,会对实际样品中铅元素的测量产生影响。在薄样和防护铅板之间加上一层隔离材料,可有效避免防护铅板中铅谱线对样品测量产生的干扰。(3)以型号316不锈钢、黄铜、铝材、紫铜和聚四氟乙烯几种硬质隔离材料作为铅板内衬材料进行选择研究,结果表明:紫铜的X射线荧光光谱中所含元素的谱线最少,谱图中没有出现重金属Cr ,Cd ,Pb的谱峰,并且能量较高部分靶材散射光谱强度较弱,对实际样品中重金属元素Cr ,Cd和Pb的测量不会产生干扰,作为铅板的内衬金属材料可以避免防护铅板中铅元素谱线的干扰,是最佳的薄膜法X射线荧光光谱分析中铅板的内衬金属材料。该研究为组装及搭建便携式大气及水体重金属X射线荧光光谱分析仪提供了重要的理论依据。%(1) In this paper type 316 stainless steel metal plate as the research object ,the selection of sample detecting position was studied when thin film method X-ray fluorescence measurement was conducted .The study showed that the optimal location for the sample detection was sample distance X-ray tube and detector baseline 1cm with the baseline into a 16°angle .(2) Heavy metal pollutants of Pb ,Cd and Cr in industrial ambient air as the main analysis object ,when thin film method X-ray fluorescence conducted with lead plate protection ,X-rays

  17. Searching for supergiant fast X-ray transients with Swift

    CERN Document Server

    Romano, P; Esposito, P; Sbarufatti, B; Haberl, F; Ponti, G; D'Avanzo, P; Ducci, L; Segreto, A; Jin, C; Masetti, N; Del Santo, M; Campana, S; Mangano, V

    2016-01-01

    Supergiant fast X-ray transients (SFXTs) are high mass X-ray binaries (HMXBs) hosting a neutron star and an OB supergiant companion. We examine the available Swift data, as well as other new or archival/serendipitous data, on three sources: IGR J17407-2808, 2XMM J185114.3-000004, and IGR J18175-2419, whose X-ray characteristics qualify them as candidate SFXT, in order to explore their properties and test whether they are consistent with an SFXT nature. As IGR J17407-2808 and 2XMM J185114.3-000004 triggered the Burst Alert Telescope on board Swift, the Swift data allow us to provide their first arcsecond localisations, leading to an unequivocal identification of the source CXOU J174042.0-280724 as the soft X-ray counterpart of IGR J17407-2808, as well as their first broadband spectra, which can be fit with models generally describing accreting neutron stars in HMXBs. While still lacking optical spectroscopy to assess the spectral type of the companion, we propose 2XMM J185114.3-000004 as a very strong SFXT can...

  18. 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...

  19. Calibration of X-ray absorption in our Galaxy

    CERN Document Server

    Willingale, R; Beardmore, A P; Tanvir, N R; O'Brien, P T

    2013-01-01

    Prediction of the soft X-ray absorption along lines of sight through our Galaxy is crucial for understanding the spectra of extragalactic sources, but requires a good estimate of the foreground column density of photoelectric absorbing species. Assuming uniform elemental abundances this reduces to having a good estimate of the total hydrogen column density, N(Htot)=N(HI)+2N(H2). The atomic component, N(HI), is reliably provided using the mapped 21 cm radio emission but estimating the molecular hydrogen column density, N(H2), expected for any particular direction, is difficult. The X-ray afterglows of GRBs are ideal sources to probe X-ray absorption in our Galaxy because they are extragalactic, numerous, bright, have simple spectra and occur randomly across the entire sky. We describe an empirical method, utilizing 493 afterglows detected by the Swift XRT, to determine N(Htot) through the Milky Way which provides an improved estimate of the X-ray absorption in our Galaxy and thereby leads to more reliable meas...

  20. X-ray diffraction at Matter in Extreme Conditions endstation

    Science.gov (United States)

    Xing, Zhou; Galtier, Eric; Lee, Hae Ja; Nagler, Bob

    2015-11-01

    Understanding dynamic response at the atomic level under extreme conditions is highly sought after goal to science frontiers studying warm dense matter, high pressure, geoscience, astrophysics, and planetary science. Thus it is of importance to determine the high pressure phases or metastable phases of material under shock compression. In situ X-ray diffraction technique using LCLS free electron laser X-ray is a powerful tool to record structural behavior and microstructure evolution in dense matter. Shock-induced compression and phase transitions of material lead to changes of the lattice spacing or evolution of new X-ray diffraction patterns. In this talk, we describe a platform dedicated for the X-ray diffraction studies at Matter in Extreme Conditions (MEC), which can be used to reconstruct a complete diffraction pattern from numerous detectors, optimize detector positioning in a timely manner, extract the lattice spacing profiles and texture features. This platform is available to the user community for real-time analysis. We will also discuss experimental results, using this platform, on the crystalline silicon phase transitions up to 60 GPa.

  1. [Flat-panel detectors in X-ray systems].

    Science.gov (United States)

    Spahn, M; Heer, V; Freytag, R

    2003-05-01

    For all application segments X-ray systems with flat-panel detectors increasingly enter the market. In digital radiography,mammography and cardiologic angiography flat-panel detectors are already well established while they are made ready for market introduction in general angiography and fluoroscopy. Two flat-panel detector technologies are available. One technology is based on an indirect conversion process of X-rays while the other one uses a direct conversion method. For radiography and dynamic applications the indirect method provides substantial advantages, while the direct method has some benefits for mammography. In radiography and mammography flat-panel detectors lead to clear improvements with respect to workflow, image quality and dose reduction potentials. These improvements are fostered by the immediate availability of the image, the large dynamic range and the high sensitivity to X-rays. New applications and the use of complex image processing algorithms have the potential to enlarge the present diagnostic range of applications. Up to now, image intensifiers are still the well-established technology for angiography and fluoroscopy. Nevertheless flat-panel detectors begin to enter this field, especially in cardiologic angiography. Characteristics of flat-panel detectors such as the availability of distortion-free images, the excellent contrast resolution, the large dynamic range, the high sensitivity to X-rays and the usability in magnetic fields provide the basis for improved and new diagnostic and interventional methods.

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

    Science.gov (United States)

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

    2015-03-01

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

  3. 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.

  4. X-ray induced optical reflectivity

    Directory of Open Access Journals (Sweden)

    Stephen M. Durbin

    2012-12-01

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

  5. 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.

  6. 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.

  7. Astrophysics: Unexpected X-ray flares

    Science.gov (United States)

    Campana, Sergio

    2016-10-01

    Two sources of highly energetic flares have been discovered in archival X-ray data of 70 nearby galaxies. These flares have an undetermined origin and might represent previously unknown astrophysical phenomena. See Letter p.356

  8. 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....

  9. 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...

  10. 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...

  11. 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...

  12. X-ray crystallographic studies of metalloproteins.

    Science.gov (United States)

    Volbeda, Anne

    2014-01-01

    Many proteins require metals for their physiological function. In combination with spectroscopic characterizations, X-ray crystallography is a very powerful method to correlate the function of protein-bound metal sites with their structure. Due to their special X-ray scattering properties, specific metals may be located in metalloprotein structures and eventually used for phasing the diffracted X-rays by the method of Multi-wavelength Anomalous Dispersion (MAD). How this is done is the principle subject of this chapter. Attention is also given to the crystallographic characterization of different oxidation states of redox active metals and to the complication of structural changes that may be induced by X-ray irradiation of protein crystals.

  13. 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)

  14. 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 ...

  15. Milli X-Ray Fluorescence Spectrometer

    Data.gov (United States)

    Federal Laboratory Consortium — The Eagle III Micro XRF unit is similar to a traditional XRF unit, with the primary difference being that the X-rays are focused by a polycapillary optic into a spot...

  16. 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.

  17. 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.

  18. Capillary Optics generate stronger X-rays

    Science.gov (United States)

    1996-01-01

    NASA scientist, in the Space Sciences lab at Marshall, works with capillary optics that generate more intense X-rays than conventional sources. This capability is useful in studying the structure of important proteins.

  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. Spectroscopy in X-ray astronomy

    Science.gov (United States)

    Andresen, R.

    1981-01-01

    Detailed features in cosmic X-ray sources and their associated temporal variation over a wide energy range were studied. Excess emission and absorption at approximately 6 to 7 kiloelectron volts in the spectra of supernova remnants, binary X-ray sources, and clusters of galaxies were observed. A gas scintillation proportional counter (GSPC) will be used as the detector system. In the gas scintillator the principal limitation is due to the statistics of the initial ionization process only.

  1. Globular cluster x-ray sources.

    Science.gov (United States)

    Pooley, David

    2010-04-20

    Globular clusters and x-ray astronomy have a long and fruitful history. Uhuru and OSO-7 revealed highly luminous (> 10(36) ergs(-1)) x-ray sources in globular clusters, and Einstein and ROSAT revealed a larger population of low-luminosity (luminosity sources were low-mass x-ray binaries in outburst and that they were orders of magnitude more abundant per unit mass in globular clusters than in the rest of the galaxy. However, the low-luminosity sources proved difficult to classify. Many ideas were put forth--low-mass x-ray binaries in quiescence (qLMXBs), cataclysmic variables (CVs), active main-sequence binaries (ABs), and millisecond pulsars (MSPs)--but secure identifications were scarce. In ROSAT observations of 55 clusters, about 25 low-luminosity sources were found. Chandra has now observed over 80 Galactic globular clusters, and these observations have revealed over 1,500 x-ray sources. The superb angular resolution has allowed for many counterpart identifications, providing clues to the nature of this population. It is a heterogeneous mix of qLMXBs, CVs, ABs, and MSPs, and it has been shown that the qLMXBs and CVs are both, in part, overabundant like the luminous LMXBs. The number of x-ray sources in a cluster correlates very well with its encounter frequency. This points to dynamical formation scenarios for the x-ray sources and shows them to be excellent tracers of the complicated internal dynamics. The relation between the encounter frequency and the number of x-ray sources has been used to suggest that we have misunderstood the dynamical states of globular clusters.

  2. Globular cluster x-ray sources

    Science.gov (United States)

    Pooley, David

    2010-01-01

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

  3. Lacquer polishing of X-ray optics

    Science.gov (United States)

    Catura, R. C.; Joki, E. G.; Roethig, D. T.; Brookover, W. J.

    1987-01-01

    Techniques for polishing figured X-ray optics by a lacquer-coating process are described. This acrylic lacquer coating has been applied with an optical quality of an eighth-wave in red light and very effectively covers surface roughness with spatial wavelengths less than about 0.2 mm. Tungsten films have been deposited on the lacquer coatings to provide highly efficient X-ray reflectivity.

  4. X-ray scattering from dense plasmas

    Energy Technology Data Exchange (ETDEWEB)

    McSherry, D.J

    2000-09-01

    Dense plasmas were studied by probing them with kilovolt x-rays and measuring those scattered at various angles. The Laser-Produced x-ray source emitted Ti He alpha 4.75 keV x-rays. Two different plasma types were explored. The first was created by laser driven shocks on either side of a sample foil consisting of 2 micron Al layer, sandwiched between two 1 micron CH layers. We have observed a peak in the x-ray scattering cross section, indicating diffraction from the plasma. However, the experimentally inferred plasma density, broadly speaking, did not always agree with the hydrodynamic simulation MEDX (A modified version of MEDUSA). The second plasma type that we studied was created by soft x-ray heating on either side of a sample foil, this time consisting of 1 micron layer of Al, sandwiched between two 0.2 micron CH layers. Two foil targets, each consisting of a 0.1 micron thick Au foil mounted on 1 micron of CH, where placed 4 mm from the sample foil. The soft x-rays where produced by laser irradiating these two foil targets. We found that, 0.5 ns after the peak of the laser heating pulses, the measured cross sections more closely matched those simulated using the Thomas Fermi model than the Inferno model. Later in time, at 2 ns, the plasma is approaching a weakly coupled state. This is the first time x-ray scattering cross sections have been measured from dense plasmas generated by radiatively heating both sides of the sample. Moreover, these are absolute values typically within a factor of two of expectation for early x-ray probe times. (author)

  5. X-ray induced optical reflectivity

    OpenAIRE

    2012-01-01

    The change in optical reflectivity induced by intense x-ray pulses can now be used to study ultrafast many body responses in solids in the femtosecond time domain. X-ray absorption creates photoelectrons and core level holes subsequently filled by Auger or fluorescence processes, and these excitations ultimately add conduction and valence band carriers that perturb optical reflectivity. Optical absorption associated with band filling and band gap narrowing is shown to explain the basic featur...

  6. X- rays and matter- the basic interactions

    DEFF Research Database (Denmark)

    Als-Nielsen, Jens

    2008-01-01

    In this introductory article we attempt to provide the theoretical basis for developing the interaction between X-rays and matter, so that one can unravel properties of matter by interpretation of X-ray experiments on samples. We emphasize that we are dealing with the basics, which means that we ...... this article: J. Als-Nielsen, C. R. Physique 9 (2008). Udgivelsesdato: 18 April...

  7. 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

  8. Determination of cadmium,lead and inorganic arsenic in rice by X - ray fluorescence spectrometer%X射线荧光光谱法测定稻谷中镉、铅和无机砷

    Institute of Scientific and Technical Information of China (English)

    骆倩; 张谷平; 赵美凤; 宁晖; 房芳; 杜文凯; 高梦莎

    2016-01-01

    The contents of cadmium,lead and total arsenic in rice were determined by three types of X -ray fluorescence spectrometer and were compared with determination of cadmium by national standard GB / T 5009. 15 - 2003,determination of lead by national standard GB / T 5009. 12 - 2003 and determina-tion of inorganic arsenic by national standard GB / T 5009. 11 - 2003. The results of 67 samples showed that three regression equations were Y = 0. 849 5X + 0. 062 1,Y = 0. 619 7X + 0. 049 3 and Y = 0. 872X+ 0. 006 4,with correlation coefficient 0. 971 1,0. 850 9 and 0. 972 9,respectively,which showed a very significant correlation. The qualitative judgment correct rate reached 65. 7%~ 91. 0% . For the tes-ting result which was in the range of 0. 16 mg / kg ~ 0. 24 mg / kg,the qualitative judgment correct rate was 38. 1%~ 81. 0%,out of the range the qualitative judgment correct rate was 78. 3%~ 95. 7% . The quan-titative judgment coincidence rate reached19. 4%~ 44. 8% . For testing result which was lower than or e-qual to 0. 2mg / kg (≤0. 2 mg / kg),its coincidence rate was 17. 6% ~ 37. 3%,otherwise,the coinci-dence rate was 25. 0%~ 68. 8% .%选用3种型号X 射线荧光光谱仪,测定稻谷样品中的镉、铅和总砷含量,并分别与GB/ T 5009.15—2003镉、GB/ T 5009.12—2003铅和GB/ T 5009.11—2003无机砷标准方法测定结果进行比较。67个稻谷样品镉测定结果比较表明,两者的相关系数分别为0.9711、0.8509和0.9729,均呈极显著相关,回归方程分别为Y =0.8495X +0.0621、Y =0.6197X +0.0493和Y =0.872X +0.0064;定性判定正确率为65.7%~91.0%,检测结果在0.16 mg / kg≤0≤0.24 mg / kg 范围内,定性判定正确率在38.1%~81.0%,检测结果在<0.16 mg / kg或>0.24 mg / kg范围内,定性判定正确率在78.3%~95.7%;定量判定符合率在19.4%~44.8%,检测结果在≤0.2 mg / kg 范围

  9. Elliptical X-Ray Spot Measurement

    CERN Document Server

    Richardson, R A; Weir, J T; Richardson, Roger A.; Sampayan, Stephen; Weir, John T.

    2000-01-01

    The so-called roll bar measurement uses a heavy metal material, optically thick to x-rays, to form a shadow of the x-ray origination spot. This spot is where an energetic electron beam interacts with a high Z target. The material (the "roll bar") is slightly curved to avoid alignment problems. The roll bar is constructed and positioned so that the x-rays are shadowed in the horizontal and vertical directions, so information is obtained in two dimensions. If a beam profile is assumed (or measured by other means), the equivalent x-ray spot size can be calculated from the x-ray shadow cast by the roll bar. Thus the ellipticity of the beam can be calculated, assuming the ellipse of the x-ray spot is aligned with the roll bar. The data is recorded using a scintillator and gated camera. Data will be presented from measurements using the ETA II induction LINAC. The accuracy of the measurement is checked using small elliptical targets.

  10. 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.

  11. The X-ray imager on AXO

    Science.gov (United States)

    Budtz-Jørgensen, C.; Kuvvetli, I.; Westergaard, N. J.; Jonasson, P.; Reglero, V.; Eyles, C.

    2001-02-01

    DSRI has initiated a development program of CZT X-ray and gamma-ray detectors employing strip readout techniques. A dramatic improvement of the energy response was found operating the detectors as the so-called drift detectors. For the electronic readout, modern ASIC chips were investigated. Modular design and the low-power electronics will make large area detectors using the drift strip method feasible. The performance of a prototype CZT system will be presented and discussed. One such detector system has been proposed for future space missions: the X-Ray Imager (XRI) on the Atmospheric X-ray Observatory (AXO), which is a mission proposed to the Danish Small Satellite Program and is dedicated to observations of X-ray generating processes in the Earth's atmosphere. Of special interest will be simultaneous optical and X-ray observations of sprites that are flashes appearing directly above an active thunderstorm system. Additional objective is a detailed mapping of the auroral X-ray and optical emission. XRI comprises a coded mask and a 20×40 cm 2 CZT detector array covering an energy range from 5 to 200 keV.

  12. Coherence in X-ray physics.

    Science.gov (United States)

    Lengeler, B

    2001-06-01

    Highly brilliant synchrotron radiation sources have opened up the possibility of using coherent X-rays in spectroscopy and imaging. Coherent X-rays are characterized by a large lateral coherence length. Speckle spectroscopy is extended to hard X-rays, improving the resolution to the nm range. It has become possible to image opaque objects in phase contrast with a sensitivity far superior to imaging in absorption contrast. All the currently available X-ray sources are chaotic sources. Their characterization in terms of coherence functions of the first and second order is introduced. The concept of coherence volume, defined in quantum optics terms, is generalized for scattering experiments. When the illuminated sample volume is smaller than the coherence volume, the individuality of the defect arrangement in a sample shows up as speckle in the scattered intensity. Otherwise, a configurational average washes out the speckle and only diffuse scattering and possibly Bragg reflections will survive. The loss of interference due to the finite detection time, to the finite detector pixel size and to uncontrolled degrees of freedom in the sample is discussed at length. A comparison between X-ray scattering, neutron scattering and mesoscopic electron transport is given. A few examples illustrate the possibilities of coherent X-rays for imaging and intensity correlation spectroscopy.

  13. 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,

  14. Echoes in X-ray Binaries

    CERN Document Server

    O'Brien, K; Hynes, R; Chen, W; Haswell, C; Still, M

    2002-01-01

    We present a method of analysing the correlated X-ray and optical/UV variability in X-ray binaries, using the observed time delays between the X-ray driving lightcurves and their reprocessed optical echoes. This allows us to determine the distribution of reprocessing sites within the binary. We model the time-delay transfer functions by simulating the distribution of reprocessing regions, using geometrical and binary parameters. We construct best-fit time-delay transfer functions, showing the regions in the binary responsible for the reprocessing of X-rays. We have applied this model to observations of the Soft X-ray Transient, GRO j1655-40. We find the optical variability lags the X-ray variability with a mean time delay of 19.3$pm{2.2}$ seconds. This means that the outer regions of the accretion disc are the dominant reprocessing site in this system. On fitting the data to a simple geometric model, we derive a best-fit disk half-opening angle of 13.5$^{+2.1}_{-2.8}$ degrees, which is similar to that observe...

  15. 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.

  16. Optics for coherent X-ray applications

    Energy Technology Data Exchange (ETDEWEB)

    Yabashi, Makina, E-mail: yabashi@spring8.or.jp [RIKEN SPring-8 Center, Kouto 1-1-1, Sayo, Hyogo 679-5148 (Japan); Tono, Kensuke [Japan Synchrotron Radiation Research Institute (JASRI), Kouto 1-1-1, Sayo, Hyogo 679-5198 (Japan); Mimura, Hidekazu [The University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-8656 (Japan); Matsuyama, Satoshi; Yamauchi, Kazuto [Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871 (Japan); Tanaka, Takashi; Tanaka, Hitoshi; Tamasaku, Kenji [RIKEN SPring-8 Center, Kouto 1-1-1, Sayo, Hyogo 679-5148 (Japan); Ohashi, Haruhiko; Goto, Shunji [Japan Synchrotron Radiation Research Institute (JASRI), Kouto 1-1-1, Sayo, Hyogo 679-5198 (Japan); Ishikawa, Tetsuya [RIKEN SPring-8 Center, Kouto 1-1-1, Sayo, Hyogo 679-5148 (Japan)

    2014-08-27

    Developments of optics for coherent X-ray applications and their role in diffraction-limited storage rings are described. 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.

  17. UK contributions to the development of X-ray astronomy as a major international discipline.

    Science.gov (United States)

    Pounds, K.; Watson, M.

    The historic discovery of Sco X-1 in 1962 found space science groups at UCL and Leicester well placed to respond, having a solar X-ray instrument currently in orbit and the proven and versatile Skylark sounding rocket available. Increasingly sophisticated experiments flown on Skylark from 1967 helped build scientific and technical expertise, leading to the successful Ariel 5 satellite, launched in 1974. Over the following 6 years, Ariel 5 made a number of seminal discoveries, including the first uncontested stellar black hole binary, multi-million degree gas pervading galaxy clusters, and powerful X-ray emission from Seyfert galaxies. Although by 1980 funding cuts had led to termination of the Ariel and Skylark programmes, UK university groups were able to continue a leading role in the first ESA X-ray satellite and contribute significantly to major X-ray astronomy projects led by Japan and Germany. The respective {EXOSAT}, {Ginga} and {ROSAT} missions ensured X-ray astronomy continued to grow strongly during an unplanned 20-year gap between NASA X-ray astronomy missions, a residual benefit being the strong international base of X-ray astronomy, currently providing powerful and complementary X-ray Observatories from the USA, Europe and Japan.

  18. Explosives detection using photoneutrons produced by X-rays

    Science.gov (United States)

    Yang, Yigang; Li, Yuanjing; Wang, Haidong; Li, Tiezhu; Wu, Bin

    2007-08-01

    The detection of explosives has become a critical issue after recent terrorist attacks. This paper describes research on explosives detection using photoneutrons from a photoneutron convertor that consists of 20 kg heavy water in an aluminum container whose shape was optimized to most effectively convert X-rays to photoneutrons. The X-rays were produced by a 9 MeV electron accelerator with an average electron current of 100 μA, resulted in a photoneutron yield of >10 11 n/s. Monte-Carlo simulations show that the radiation field is composed of X-ray pulses, fast neutron pulses and thermal neutrons. Both the X-ray and fast neutron pulses are 5 μs wide with a 300 Hz repetition frequency. The thermal neutron flux, which is higher than 10 4 n/cm 2/s, is essentially time invariant. A time shielding circuit was developed for the spectrometry system to halt the sampling process during the intense X-ray pulses. Paraffin, boron carbide and lead were used to protect the detector from interference from the X-rays, fast neutrons, thermal neutrons and background γ-rays coming from the system materials induced by photoneutrons. 5″×5″ NaI (Tl) scintillators were chosen as the detectors to detect the photoneutrons induced γ-rays from the inspected explosive simulant. Nitrogen (6.01 cps) 10.828 MeV γ-rays were detected with one detector from a 50 kg carbamide block placed 60 cm in front of the detector. A collimator was used to reduce the number of background 10.828 MeV γ-rays coming from the nitrogen in the air to improve the signal to background ratio from 0.136 to 1.81. A detector array of seven 5″×5″ NaI (Tl) detectors was used to measure the 2-D distributions of N and H in the sample. The combination of photoneutron analysis and X-ray imaging shows promise for enhancing explosives detection capabilities.

  19. X-ray imaging in advanced studies of ophthalmic diseases.

    Science.gov (United States)

    Antunes, Andrea; Safatle, Angélica M V; Barros, Paulo S M; Morelhão, Sérgio L

    2006-07-01

    Microscopic characterization of pathological tissues has one major intrinsic limitation, the small sampling areas with respect to the extension of the tissues. Mapping possible changes on vast tissues and correlating them with large ensembles of clinical cases is not a feasible procedure for studying most diseases, as for instance vision loss related diseases and, in particular, the cataract. Although intraocular lens implants are successful treatments, cataract still is a leading public-health issue that grows in importance as the population increases and life expectancy is extended worldwide. In this work we have exploited the radiation-tissue interaction properties of hard x-rays--very low absorption and scattering--to map distinct lesions on entire eye lenses. At the used synchrotron x-ray photon energy of 20 keV (wavelength lambda=0.062 nm), scattering and refraction are angular resolved effects. It allows the employed x-ray image technique to efficiently characterize two types of lesions in eye lenses under cataractogenesis: distributions of tiny scattering centers and extended areas of fiber cell compaction. The data collection procedure is relatively fast; allowing dozens of samples to be totally imaged (scattering, refraction, and mass absorption images) in a single day of synchrotron beam time. More than 60 cases of canine cataract, not correlated to specific causes, were investigated in this first application of x-rays to image entire lenses. Cortical opacity cases, or partial opacity, could be related to the presence of calcificated tissues at the cortical areas, clearly visible in the images, whose elemental contents were verified by micro x-ray fluorescence as very rich in calcium. Calcificated tissues were also observed at nuclear areas in some cases of hypermature cataract. Total opacity cases without distinguishable amount of scattering centers consist in 70% of the analyzed cases, where remarkable fissure marks owing to extended areas of fiber

  20. X-ray ablation measurements and modeling for ICF applications

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Andrew Thomas [Univ. of California, Berkeley, CA (United States)

    1996-09-01

    X-ray ablation of material from the first wall and other components of an ICF (Inertial Confinement Fusion) chamber is a major threat to the laser final optics. Material condensing on these optics after a shot may cause damage with subsequent laser shots. To ensure the successful operation of the ICF facility, removal rates must be predicted accurately. The goal for this dissertation is to develop an experimentally validated x-ray response model, with particular application to the National Ignition Facility (NIF). Accurate knowledge of the x-ray and debris emissions from ICF targets is a critical first step in the process of predicting the performance of the target chamber system. A number of 1-D numerical simulations of NIF targets have been run to characterize target output in terms of energy, angular distribution, spectrum, and pulse shape. Scaling of output characteristics with variations of both target yield and hohlraum wall thickness are also described. Experiments have been conducted at the Nova laser on the effects of relevant x-ray fluences on various materials. The response was diagnosed using post-shot examinations of the surfaces with scanning electron microscope and atomic force microscope instruments. Judgments were made about the dominant removal mechanisms for each material. Measurements of removal depths were made to provide data for the modeling. The finite difference ablation code developed here (ABLATOR) combines the thermomechanical response of materials to x-rays with models of various removal mechanisms. The former aspect refers to energy deposition in such small characteristic depths (~ micron) that thermal conduction and hydrodynamic motion are significant effects on the nanosecond time scale. The material removal models use the resulting time histories of temperature and pressure-profiles, along with ancillary local conditions, to predict rates of surface vaporization and the onset of conditions that would lead to spallation.

  1. X-ray ablation measurements and modeling for ICF applications

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, A.T.

    1996-09-01

    X-ray ablation of material from the first wall and other components of an ICF (Inertial Confinement Fusion) chamber is a major threat to the laser final optics. Material condensing on these optics after a shot may cause damage with subsequent laser shots. To ensure the successful operation of the ICF facility, removal rates must be predicted accurately. The goal for this dissertation is to develop an experimentally validated x-ray response model, with particular application to the National Ignition Facility (NIF). Accurate knowledge of the x-ray and debris emissions from ICF targets is a critical first step in the process of predicting the performance of the target chamber system. A number of 1-D numerical simulations of NIF targets have been run to characterize target output in terms of energy, angular distribution, spectrum, and pulse shape. Scaling of output characteristics with variations of both target yield and hohlraum wall thickness are also described. Experiments have been conducted at the Nova laser on the effects of relevant x-ray fluences on various materials. The response was diagnosed using post-shot examinations of the surfaces with scanning electron microscope and atomic force microscope instruments. Judgments were made about the dominant removal mechanisms for each material. Measurements of removal depths were made to provide data for the modeling. The finite difference ablation code developed here (ABLATOR) combines the thermomechanical response of materials to x-rays with models of various removal mechanisms. The former aspect refers to energy deposition in such small characteristic depths ({approx} micron) that thermal conduction and hydrodynamic motion are significant effects on the nanosecond time scale. The material removal models use the resulting time histories of temperature and pressure-profiles, along with ancillary local conditions, to predict rates of surface vaporization and the onset of conditions that would lead to spallation.

  2. X-ray excited optical luminescence, photoluminescence, photostimulated luminescence and x-ray photoemission spectroscopy studies on BaFBr:Eu

    CERN Document Server

    Subramanian, N; Govinda-Rajan, K; Mohammad-Yousuf; Santanu-Bera; Narasimhan, S V

    1997-01-01

    The results of x-ray excited optical luminescence (XEOL), photoluminescence (PL), photostimulated luminescence (PSL) and x-ray photoemission spectroscopy (XPS) studies on the x-ray storage phosphor BaFBr:Eu are presented in this paper. Analyses of XEOL, PL and PSL spectra reveal features corresponding to the transitions from 4f sup 6 td sup 1 to 4f sup 7 configurations in different site symmetries of Eu sup 2 sup +. Increasing x-ray dose is seen to lead to a red shift in the maximum of the PL excitation spectrum for the 391 nm emission. The XEOL and XPS spectra do not show any signature of Eu sup 3 sup + in the samples studied by us, directly raising doubts about the model of Takahashi et al in which Eu sup 2 sup + is expected to ionize to Eu sup 3 sup + upon x-ray irradiation and remain stable until photostimulation. XEOL and PSL experiments with simultaneous x-ray irradiation and He - Ne laser excitation as well as those with sequential x-ray irradiation and laser stimulation bring out the competition betwe...

  3. A Monte Carlo study of x-ray fluorescence in x-ray detectors.

    Science.gov (United States)

    Boone, J M; Seibert, J A; Sabol, J M; Tecotzky, M

    1999-06-01

    Advances in digital x-ray detector systems have led to a renewed interest in the performance of x-ray phosphors and other detector materials. Indirect flat panel x-ray detector and charged coupled device (CCD) systems require a more technologically challenging geometry, whereby the x-ray beam is incident on the front side of the scintillator, and the light produced must diffuse to the back surface of the screen to reach the photoreceptor. Direct detector systems based on selenium have also enjoyed a growing interest, both commercially and academically. Monte Carlo simulation techniques were used to study the x-ray scattering (Rayleigh and Compton) and the more prevalent x-ray fluorescence properties of seven different x-ray detector materials, Gd2O2S, CsI, Se, BaFBr, YTaO4, CaWO4, and ThO2. The redistribution of x-ray energy, back towards the x-ray source, in a forward direction through the detector, and lateral reabsorption in the detector was computed under monoenergetic conditions (1 keV to 130 keV by 1 keV intervals) with five detector thicknesses, 30, 60, 90, 120, and 150 mg/cm2 (Se was studied from 30 to 1000 mg/cm2). The radial distribution (related to the point spread function) of reabsorbed x-ray energy was also determined. Representative results are as follows: At 55 keV, more (31.3%) of the incident x-ray energy escaped from a 90 mg/cm2Gd2O2S detector than was absorbed (27.9%). Approximately 1% of the total absorbed energy was reabsorbed greater than 0.5 mm from the primary interaction, for 90 mg/cm2 CsI exposed at 100 kVp. The ratio of reabsorbed secondary (fluorescence + scatter) radiation to the primary radiation absorbed in the detectors (90 mg/cm2) (S/P) was determined as 10%, 16%, 2%, 12%, 3%, 3%, and 0.3% for a 100 kVp tungsten anode x-ray spectrum, for the Gd2O2S, CsI, Se, BaFBr, YTaO4, CaWO4, and ThO2 detectors, respectively. The results indicate significant x-ray fluorescent escape and reabsorption in common x-ray detectors. These findings

  4. 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.

  5. Systematic Errors in Dimensional X-ray Computed Tomography

    DEFF Research Database (Denmark)

    of the measurement. As a consequence, there is a high risk that on the basis of defective measurement results, a manufactured product is wrongly rejected in conformance testing. According to guidelines and standards, systematic error influences on a final measurand must be avoided or at least known so......A result of a measurement is usually affected by a measurement error which cannot be avoided in practice. Particularly in production metrology, systematic errors from, e.g, temperature influences, drift effects, etc., may lead to high measurement deviation in respect to the true value...... that it is possible to compensate them. In dimensional X-ray computed tomography (CT), many physical quantities influence the final result. However, it is important to know which factors in CT measurements potentially lead to systematic errors. In this talk, typical error sources in dimensional X-ray CT are discussed...

  6. Evaluating X-ray absorption of nano-bismuth oxide ointment for decreasing risks associated with X-ray exposure among operating room personnel and radiology experts

    Directory of Open Access Journals (Sweden)

    M. Rashidi

    2015-12-01

      Conclusion: It seems that due to higher atomic number and lower toxicity, Bi2O3 nanoparticles have better efficiency in X-ray absorbtion, comparing to the lead. Cream and ointment of bismuth oxide nanoparticles can be used as X-ray absorbant for different professions such as physicians, dentists, radiology experts, and operating room staff and consequently increase health and safety of these employees.

  7. Low energy x-ray spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Woodruff, W.R.

    1981-06-05

    A subkilovolt spectrometer has been produced to permit high-energy-resolution, time-dependent x-ray intensity measurements. The diffracting element is a curved mica (d = 9.95A) crystal. To preclude higher order (n > 1) diffractions, a carbon x-ray mirror that reflects only photons with energies less than approx. 1.1 keV is utilized ahead of the diffracting element. The nominal energy range of interest is 800 to 900 eV. The diffracted photons are detected by a gold-surface photoelectric diode designed to have a very good frequency response, and whose current is recorded on an oscilloscope. A thin, aluminium light barrier is placed between the diffracting crystal and the photoelectric diode detector to keep any uv generated on or scattered by the crystal from illuminating the detector. High spectral energy resolution is provided by many photocathodes between 8- and 50-eV wide placed serially along the diffracted x-ray beam at the detector position. The spectrometer was calibrated for energy and energy dispersion using the Ni L..cap alpha../sub 1/ /sub 2/ lines produced in the LLNL IONAC accelerator and in third order using a molybdenum target x-ray tube. For the latter calibration the carbon mirror was replaced by one surfaced with rhodium to raise the cut-off energy to about 3 keV. The carbon mirror reflection dependence on energy was measured using one of our Henke x-ray sources. The curved mica crystal diffraction efficiency was measured on our Low-Energy x-ray (LEX) machine. The spectrometer performs well although some changes in the way the x-ray mirror is held are desirable. 16 figures.

  8. 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.

  9. Low Energy Plasma Focus as an Intense X-ray Source for Radiography

    Institute of Scientific and Technical Information of China (English)

    S. Hussain; M. Zakaullah; Shujaat Ali; A. Waheed

    2004-01-01

    Study on X-ray emission from a low energy (1.8 k J) plasma focus device powered by a 9 μF capacitor bank, charged at 20 kV and giving peak discharge current of about 175 kA by using a lead-inserted copper-tapered anode is reported. The X-ray yield in different energy windows is measured as a function of hydrogen filling pressure. The maximum yield in 4π-geometry is found to be (27.3±1.1) J and corresponding wall plug efficiency for X-ray generation is 1.52 ±0.06%. X-ray emission, presumably due to bombarding activity of electrons in current sheath at the anode tip was dominant, which is confirmed by the pinhole images. The feasibility of the device as an intense X-ray source for radiography is demonstrated.

  10. Suzaku Detection of Diffuse Hard X-Ray Emission outside Vela X

    CERN Document Server

    Katsuda, Satoru; Petre, Robert; Yamaguchi, Hiroya; Tsunemi, Hiroshi; Bocchino, Fabrizio; Bamba, Aya; Miceli, Marco; Hewitt, John W; Temim, Tea; Uchida, Hiroyuki; Yoshii, Rie

    2011-01-01

    Vela X is a large, 3x2 degrees, radio-emitting pulsar wind nebula (PWN) powered by the Vela pulsar in the Vela supernova remnant. Using four Suzaku/XIS observations pointed just outside Vela X, we find hard X-ray emission extending throughout the fields of view. The hard X-ray spectra are well represented by a power-law. The photon index is measured to be constant at Gamma~2.4, similar to that of the southern outer part of Vela X. The power-law flux decreases with increasing distance from the pulsar. These properties lead us to propose that the hard X-ray emission is associated with the Vela PWN. The larger X-ray extension found in this work strongly suggests that distinct populations relativistic electrons form the X-ray PWN and Vela X, as was recently inferred from multiwavelength spectral modeling of Vela X.

  11. Suzaku Detection of Diffuse Hard X-Ray Emission Outside Vela X

    Science.gov (United States)

    Katsuda, Satoru; Mori, Koji; Petre, Robert; Yamaguchi, Hiroya; Tsunemi, Hiroshi; Bocchino, Fabrizio; Bamba, Aya; Miceli, Marco; Hewitt, John W.; Temim, Tea; Uchida, Hiroyuki; Yoshii, Rie

    2011-01-01

    Vela X is a large, 3 deg x 2 deg, radio-emitting pulsar wind nebula (PWN) powered by the Vela pulsar in the Vela supernova remnant. Using four Suzaku/XIS observations pointed just outside Vela X, we find hard X-ray emission extending throughout the fields of view. The hard X-ray spectra are well represented by a power-law. The photon index is measured to be constant at Gamma approximates 2.4, similar to that of the southern outer part of Vela X. The power-law flux decreases with increasing distance from the pulsar. These properties lead us to propose that the hard X-ray emission is associated with the Vela PWN. The larger X-ray extension found in this work strongly suggests that distinct populations relativistic electrons form the X-ray PWN and Vela X, as was recently inferred from multiwavelength spectral modeling of Vela X.

  12. Stopping Narrow-Band X-Ray Pulses in Nuclear Media

    Science.gov (United States)

    Kong, Xiangjin; Pálffy, Adriana

    2016-05-01

    A control mechanism for stopping x-ray pulses in resonant nuclear media is investigated theoretically. We show that narrow-band x-ray pulses can be mapped and stored as nuclear coherence in a thin-film planar x-ray cavity with an embedded 57Fe nuclear layer. The pulse is nearly resonant to the 14.4 keV Mössbauer transition in the 57Fe nuclei. The role of the control field is played here by a hyperfine magnetic field which induces interference effects reminiscent of electromagnetically induced transparency. We show that, by switching off the control magnetic field, a narrow-band x-ray pulse can be completely stored in the cavity for approximately 100 ns. Additional manipulation of the external magnetic field can lead to both group velocity and phase control of the pulse in the x-ray cavity sample.

  13. Hard X-ray Spectroscopic, Microwave and H-alpha Linear Polarization Studies with Hard X-Ray Observations from HESSI

    Science.gov (United States)

    Kiplinger, Alan L.

    2005-01-01

    The Principal Investigator (P.I.) has been pursuing a three year grant under NASA's Sun-Earth Connection Guest Investigator Program in support of the Ramaty High Energy Solar Spectroscopic Imager (RHESSI). An objective of these efforts is to combine X-ray and other data on solar flares, coronal mass ejections and interplanetary particle events in order to obtain a more comprehensive recognition of signatures, and understanding of interplanetary proton events. Thus, part of these efforts are to investigate if signatures seen in hard X-rays and microwaves can lead to better predictions of interplanetary proton events that can be dangerous to astronauts and spacecraft. The original proposal was written in May, 2000 and it discusses a three-pronged approach for data comparisons with three new types of instrumentation observing at X-ray, microwave and optical wavelengths. The major impetus behind this work and the proposal is that the P.I. discovered a strong correlation between a particular type of hard X-ray signature seen in spectral evolutions and interplanetary proton events (Kiplinger, 1995). The basic signature is that hard X-ray flux peaks either exhibit spectra that soften on their decays (Le. show fewer and fewer high energy X-rays with time) or they harden during decays (i.e. high energy X-rays decay significantly slower that lower energy X-rays). This signature is called progressive hardening. Studies were conducted over an eight-year period of data from the Hard X-Ray Burst Spectrometer (HXRBS) of the Solar maximum mission. Out of the 750 well observed flares studied, 41 flares had major associated proton events. Of these, 29 events were predicted on the basis of progressive hardening for a hit rate of 71%. The 152 largest flares had a hit rate of 82%.

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

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Shouyuan; Golovin, Grigory [Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, NE 68588 (United States); Miller, Cameron [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Haden, Daniel; Banerjee, Sudeep; Zhang, Ping; Liu, Cheng; Zhang, Jun; Zhao, Baozhen [Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, NE 68588 (United States); Clarke, Shaun; Pozzi, Sara [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Umstadter, Donald, E-mail: donald.umstadter@unl.edu [Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, NE 68588 (United States)

    2016-01-01

    We report the results of experimental and numerical-simulation studies of shielded radiography using narrowband MeV-energy X-rays from a compact all-laser-driven inverse-Compton-scattering X-ray light source. This recently developed X-ray light source is based on a laser-wakefield accelerator with ultra-high-field gradient (GeV/cm). We demonstrate experimentally high-quality radiographic imaging (image contrast of 0.4 and signal-to-noise ratio of 2:1) of a target composed of 8-mm thick depleted uranium shielded by 80-mm thick steel, using a 6-MeV X-ray beam with a spread of 45% (FWHM) and 10{sup 7} photons in a single shot. The corresponding dose of the X-ray pulse measured in front of the target is ∼100 nGy/pulse. Simulations performed using the Monte-Carlo code MCNPX accurately reproduce the experimental results. These simulations also demonstrate that the narrow bandwidth of the Compton X-ray source operating at 6 and 9 MeV leads to a reduction of deposited dose as compared to broadband bremsstrahlung sources with the same end-point energy. The X-ray beam’s inherently low-divergence angle (∼mrad) is advantageous and effective for interrogation at standoff distance. These results demonstrate significant benefits of all-laser driven Compton X-rays for shielded radiography.

  15. 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.

  16. 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.

  17. 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.

  18. 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...

  19. Imaging in Hard X-ray Astronomy

    CERN Document Server

    Li Ti Pei

    2002-01-01

    The energy range of hard X-rays is a key waveband to the study of high energy processes in celestial objects, but still remains poorly explored. In contrast to direct imaging methods used in the low energy X-ray and high energy gamma-ray bands, currently imaging in the hard X-ray band is mainly achieved through various modulation techniques. A new inversion technique, the direct demodulation method, has been developed since early 90s. With this technique, wide field and high resolution images can be derived from scanning data of a simple collimated detector. The feasibility of this technique has been confirmed by experiment, balloon-borne observation and analyzing simulated and real astronomical data. Based the development of methodology and instrumentation, a high energy astrophysics mission -- Hard X-ray Modulation Telescope (HXMT) has been proposed and selected in China for a four-year Phase-A study. The main scientific objectives are a full-sky hard X-ray (20-200 keV) imaging survey and high signal-to-noi...

  20. X-ray emission processes in stars

    CERN Document Server

    Testa, Paola

    2010-01-01

    A decade of X-ray stellar observations with Chandra and XMM-Newton has led to significant advances in our understanding of the physical processes at work in hot (magnetized) plasmas in stars and their immediate environment, providing new perspectives and challenges, and in turn the need for improved models. The wealth of high-quality stellar spectra has allowed us to investigate, in detail, the characteristics of the X-ray emission across the HR diagram. Progress has been made in addressing issues ranging from classical stellar activity in stars with solar-like dynamos (such as flares, activity cycles, spatial and thermal structuring of the X-ray emitting plasma, evolution of X-ray activity with age), to X-ray generating processes (e.g. accretion, jets, magnetically confined winds) that were poorly understood in the pre-Chandra/XMM-Newton era. I discuss the progress made in the study of high energy stellar physics and its impact in a wider astrophysical context, focusing on the role of spectral diagnostics no...

  1. X-ray echo spectroscopy (Conference Presentation)

    Science.gov (United States)

    Shvyd'ko, Yuri V.

    2016-09-01

    X-ray echo spectroscopy, a counterpart of neutron spin-echo, was recently introduced [1] 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-meV and 0.02-meV ultra-high-resolution IXS applications (resolving power > 10^8) with broadband 5-13 meV dispersing systems will be presented featuring more than 1000-fold signal enhancement. The technique is general, applicable in different photon frequency domains. [1.] Yu. Shvyd'ko, Phys. Rev. Lett. 116, accepted (2016), arXiv:1511.01526.

  2. X-ray absorption spectroscopy of metalloproteins.

    Science.gov (United States)

    Ward, Jesse; Ollmann, Emily; Maxey, Evan; Finney, Lydia A

    2014-01-01

    Metalloproteins are enormously important in biology. While a variety of techniques exist for studying metals in biology, X-ray absorption spectroscopy is particularly useful in that it can determine the local electronic and physical structure around the metal center, and is one of the few avenues for studying "spectroscopically silent" metal ions like Zn(II) and Cu(I) that have completely filled valence bands. While X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) are useful for studying metalloprotein structure, they suffer the limitation that the detected signal is an average of all the various metal centers in the sample, which limits its usefulness for studying metal centers in situ or in cell lysates. It would be desirable to be able to separate the various proteins in a mixture prior to performing X-ray absorption studies, so that the derived signal is from one species only. Here we describe a method for performing X-ray absorption spectroscopy on protein bands following electrophoretic separation and western blotting.

  3. X-ray optics of gold nanoparticles.

    Science.gov (United States)

    Letfullin, Renat R; Rice, Colin E W; George, Thomas F

    2014-11-01

    Gold nanoparticles have been investigated as contrast agents for traditional x-ray medical procedures, utilizing the strong absorption characteristics of the nanoparticles to enhance the contrast of the detected x-ray image. Here we use the Kramers-Kronig relation for complex atomic scattering factors to find the real and imaginary parts of the index of refraction for the medium composed of single-element materials or compounds in the x-ray range of the spectrum. These complex index of refraction values are then plugged into a Lorenz-Mie theory to calculate the absorption efficiency of various size gold nanoparticles for photon energies in the 1-100 keV range. Since the output from most medical diagnostic x-ray devices follows a wide and filtered spectrum of photon energies, we introduce and compute the effective intensity-absorption-efficiency values for gold nanoparticles of radii varying from 5 to 50 nm, where we use the TASMIP model to integrate over all spectral energies generated by typical tungsten anode x-ray tubes with kilovolt potentials ranging from 50 to 150 kVp.

  4. 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...

  5. Ultrafast X-Ray Coherent Control

    Energy Technology Data Exchange (ETDEWEB)

    Reis, David

    2009-05-01

    This main purpose of this grant was to develop the nascent eld of ultrafast x-ray science using accelerator-based sources, and originally developed from an idea that a laser could modulate the di racting properties of a x-ray di racting crystal on a fast enough time scale to switch out in time a shorter slice from the already short x-ray pulses from a synchrotron. The research was carried out primarily at the Advanced Photon Source (APS) sector 7 at Argonne National Laboratory and the Sub-Picosecond Pulse Source (SPPS) at SLAC; in anticipation of the Linac Coherent Light Source (LCLS) x-ray free electron laser that became operational in 2009 at SLAC (all National User Facilities operated by BES). The research centered on the generation, control and measurement of atomic-scale dynamics in atomic, molecular optical and condensed matter systems with temporal and spatial resolution . It helped develop the ultrafast physics, techniques and scienti c case for using the unprecedented characteristics of the LCLS. The project has been very successful with results have been disseminated widely and in top journals, have been well cited in the eld, and have laid the foundation for many experiments being performed on the LCLS, the world's rst hard x-ray free electron laser.

  6. X-ray film spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez-Trelles, F.; Caputo, M.C. (Buenos Aires Univ. Nacional (Argentina). Lab. de Fisica del Plasma; Ministerio de Defensa, Buenos Aires (Argentina). DIGID)

    1982-02-15

    A multi-pinhole camera using film as a detector is described. Separation of variables in the master-curve sense leads to integral exposure equations which are solved by regularization. A filter-selection method is used to maximize the information content of a given set of measurements. Numerical simulation examples of the unfolding procedure are shown and the inversion error is evaluated. The essential role of absorption edges of filters and detectors for increasing the information content is emphasized and the method is compared with other absorption-edge techniques. A discussion of the present limitations of the method is given.

  7. Femtosecond X-ray Absorption Spectroscopy at a Hard X-ray Free Electron Laser

    DEFF Research Database (Denmark)

    Lemke, Henrik T.; Bressler, Christian; Chen, Lin X.

    2013-01-01

    X-ray free electron lasers (XFELs) deliver short (<100 fs) and intense (similar to 10(12) photons) pulses of hard X-rays, making them excellent sources for time-resolved studies. Here we show that, despite the inherent instabilities of current (SASE based) XFELs, they can be used for measuring hi...

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

    CERN Document Server

    Hamaguchi, K; Gull, T; Ishibashi, K; Pittard, J M; Hillier, D J; Damineli, A; Davidson, K; Nielsen, K E; Kober, G V; Hamaguchi, Kenji; Corcoran, Michael F.; Gull, Theodore; Ishibashi, Kazunori; Pittard, Julian M.; 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 significantly on timescales of hours. The lowest X-ray flux in the 2-10 keV band seen by XMM-Newton was only 0.7% of the maximum seen by RXTE just before the X-ray minimum. The slope of the X-ray continuum above 5 keV did not vary in any observation, which suggests that the electron temperature of the hottest plasma associated with the stellar source did not vary significantly at any phase. Through the minimum, the absorption to the stellar source increased by a factor of 5-10 to NH ~3-4E23 cm-2. The thermal Fe XXV emission line show...

  9. Hard X-ray emission from neutron star X-ray binaries

    Energy Technology Data Exchange (ETDEWEB)

    Di Salvo, T.; Santangelo, A.; Segreto, A

    2004-06-01

    In this paper we review our current knowledge of the hard X-ray emission properties of accreting X-ray Binary Pulsars and old accreting neutron stars in Low Mass X-ray Binaries in light of 7 years of BeppoSAX and RXTE observations. The paper is divided in two parts. In the first part we review the more recent findings on the phase-dependent broad band continua and cyclotron resonance scattering features observed in many systems of the X-ray Binary Pulsar class. In the second part we review the hard X-ray emission of LMXRB focussing on the hard X-ray components extending up to energies of a few hundred keV that have been clearly detected in sources of both the atoll and Z classes. The presence and characteristics of these hard emission components are then discussed in relation to source properties and spectral state. We, also, briefly mention models that have been proposed for the hard X-ray emission of neutron star X-ray binaries.

  10. X-ray Polarization from High Mass X-ray Binaries

    CERN Document Server

    Kallman, T; Blondin, J

    2015-01-01

    X-ray astronomy allows study of objects which may be associated with compact objects, i.e. neutron stars or black holes, and also may contain strong magnetic fields. Such objects are categorically non-spherical, and likely non-circular when projected on the sky. Polarization allows study of such geoemetric effects, and X-ray polarimetry is likely to become feasible for a significant number of sources in the future. A class of potential targets for future X-ray polarization observations is the high mass X-ray binaries (HMXBs), which consist of a compact object in orbit with an early type star. In this paper ws show that X-ray polarization from HMXBs has a distinct signature which depends on the source inclination and orbital phase. The presence of the X-ray source displaced from the star creates linear polarization even if the primary wind is spherically symmetric whenever the system is viewed away from conjunction. Direct X-rays dilute this polarization whenever the X-ray source is not eclipsed; at mid-eclips...

  11. X-ray Polarization in Relativistic Jets

    CERN Document Server

    McNamara, Aimee L; Wu, Kinwah

    2009-01-01

    We investigate the polarization properties of Comptonized X-rays from relativistic jets in Active Galactic Nuclei (AGN) using Monte Carlo simulations. We consider three scenarios commonly proposed for the observed X-ray emission in AGN: Compton scattering of blackbody photons emitted from an accretion disk; scattering of cosmic microwave background (CMB) photons; and self-Comptonization of intrinsically polarized synchrotron photons emitted by jet electrons. Our simulations show that for Comptonization of disk and CMB photons, the degree of polarization of the scattered photons increases with the viewing inclination angle with respect to the jet axis. In both cases the maximum linear polarization is approximately 20%. In the case of synchrotron self-Comptonization (SSC), we find that the resulting X-ray polarization depends strongly on the seed synchrotron photon injection site, with typical fractional polarizations of approximately P = 10 - 20% when synchrotron emission is localized near the jet base, while ...

  12. X-Ray Detector Simulations - Oral Presentation

    Energy Technology Data Exchange (ETDEWEB)

    Tina, Adrienne [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-08-20

    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.

  13. Bone diagnosis by X-ray techniques

    Energy Technology Data Exchange (ETDEWEB)

    Lima, I. [Nuclear Engineering Program/COPPE/UFRJ, P.O. Box 68509, Av. Horacio Macedo, 2030, Sala I-133, Cidade Universitaria, Zip Code: 21941-972 Rio de Janeiro, RJ (Brazil)], E-mail: inaya@lin.ufrj.br; Anjos, M.J. [Nuclear Engineering Program/COPPE/UFRJ, P.O. Box 68509, Av. Horacio Macedo, 2030, Sala I-133, Cidade Universitaria, Zip Code: 21941-972 Rio de Janeiro, RJ (Brazil); Physics Institute, UERJ (Brazil); Farias, M.L.F. [University Hospital, UFRJ (Brazil); Parcegoni, N.; Rosenthal, D. [Biophysics Institute, UFRJ (Brazil); Duarte, M.E.L. [Histologic and Embriology Department, UFRJ (Brazil); Lopes, R.T. [Nuclear Engineering Program/COPPE/UFRJ, P.O. Box 68509, Av. Horacio Macedo, 2030, Sala I-133, Cidade Universitaria, Zip Code: 21941-972 Rio de Janeiro, RJ (Brazil)

    2008-12-15

    In this work, two X-ray techniques used were 3D microcomputed tomography (micro-CT) and X-ray microfluorescence (micro-XRF) in order to investigate the internal structure of the bone samples. Those two techniques work together, e.g. as a complement to each other, to characterize bones structure and composition. Initially, the specimens were used to do the scan procedure in the microcomputer tomography system and the second step consists of doing the X-ray microfluorescence analysis. The results show that both techniques are powerful methods for analyzing, inspecting and characterizing bone samples: they are alternative procedures for examining bone structures and compositions and they are complementary.

  14. Microfabrication of hard x-ray lenses

    DEFF Research Database (Denmark)

    Stöhr, Frederik

    in the vertical and horizontal directions was addressed. A functioning prototype of a 2D silicon objective for use in a bright-field hard-XRM was demonstrated. The results are promising; showing acceptably low aberration and performance close to theoretical expectations. A resolution of 300 nm with 17 keV x......This thesis deals with the development of silicon compound refractive lenses (Si-CRLs) for shaping hard x-ray beams. The CRLs are to be fabricated using state of the art microfabrication techniques. The primary goal of the thesis work is to produce Si-CRLs with considerably increased structure...... intense and wider line beams with narrower waists. The thesis starts with a review of alternative x-ray lenses. Si-CRLs are identified as valuable optical components that allow shaping hard x-rays efficiently and creating beam waists that are clearly in the nanometer range. They stand out...

  15. Filtered fluorescer x-ray detector

    Energy Technology Data Exchange (ETDEWEB)

    Bruns, H.C.; Emig, J.A.; Thoe, R.S.; Springer, P.T.; Hernandez, J.A.

    1995-04-01

    Recently, an instrument capable of measuring x-rays between 8 and 90 keV was conceived to help understand conditions pertaining to pulsed power research. This resulted in the development of a versatile device that would incrementally detect x-rays emitted at predetermined energy bands over this range. To accomplish this, an array of well characterized filter-fluorescer combinations were produced which would allow fluoresced x-rays to be observed by time resolved electro-optical devices. As many as sixteen channels could be utilized with each channel having a corresponding background channel. Upon completion of the device, a three week series of experiments was then successfully carried out.

  16. X-Ray Wakes in Abell 160

    CERN Document Server

    Drake, N; Sakelliou, I; Pinkney, J C; Drake, Nick; Merrifield, Michael R.; Sakelliou, Irini; Pinkney, Jason C.

    2000-01-01

    `Wakes' of X-ray emission have now been detected trailing behind a few (at least seven) elliptical galaxies in clusters. To quantify how widespread this phenomenon is, and what its nature might be, we have obtained a deep (70 ksec) X-ray image of the poor cluster Abell 160 using the ROSAT HRI. Combining the X-ray data with optical positions of confirmed cluster members, and applying a statistic designed to search for wake-like excesses, we confirm that this phenomenon is observed in galaxies in this cluster. The probability that the detections arise from chance is less than 0.0038. Further, the wakes are not randomly distributed in direction, but are preferentially oriented pointing away from the cluster centre. This arrangement can be explained by a simple model in which wakes arise from the stripping of their host galaxies' interstellar media due to ram pressure against the intracluster medium through which they travel.

  17. Contact x-ray microscopy using Asterix

    Science.gov (United States)

    Conti, Aldo; Batani, Dimitri; Botto, Cesare; Masini, Alessandra; Bernardinello, A.; Bortolotto, Fulvia; Moret, M.; Poletti, G.; Piccoli, S.; Cotelli, F.; Lora Lamia Donin, C.; Stead, Anthony D.; Marranca, A.; Eidmann, Klaus; Flora, Francesco; Palladino, Libero; Reale, Lucia

    1997-10-01

    The use of a high energy laser source for soft x-ray contact microscopy is discussed. Several different targets were used and their emission spectra compared. The x-ray emission, inside and outside the Water Window, was characterized in detail by means of many diagnostics, including pin hole and streak cameras. Up to 12 samples holders per shot were exposed thanks to the large x-ray flux and the geometry of the interaction chamber. Images of several biological samples were obtained, including Chlamydomonas and Crethidia green algae, fish and boar sperms and Saccharomyces Cerevisiae yeast cells. A 50 nm resolution was reached on the images of boar sperm. Original information concerning the density of inner structures of Crethidia green algae were obtained.

  18. The X-ray imager on AXO

    DEFF Research Database (Denmark)

    Budtz-Jørgensen, Carl; Kuvvetli, Irfan; Westergaard, Niels Jørgen Stenfeldt

    2001-01-01

    DSRI has initiated a development program of CZT X-ray and gamma-ray detectors employing strip readout techniques. A dramatic improvement of the energy response was found operating the detectors as the so-called drift detectors. For the electronic readout, modern ASIC chips were investigated....... Modular design and the low-power electronics will make large area detectors using the drift strip method feasible. The performance of a prototype CZT system will be presented and discussed. One such detector system has been proposed for future space missions: the X-Ray Imager (XRI) on the Atmospheric X...... thunderstorm system. Additional objective is a detailed mapping of the auroral X-ray and optical emission. XRI comprises a coded mask and a 20 x 40cm(2) CZT detector array covering an energy range from 5 to 200keV....

  19. Electromagnetically induced transparency for x rays

    CERN Document Server

    Buth, Christian; Young, Linda

    2007-01-01

    Electromagnetically induced transparency (EIT) is predicted for x rays in laser-dressed neon gas. The x-ray photoabsorption cross section and polarizability near the Ne K edge are calculated using an ab initio theory suitable for optical strong-field problems. The laser wavelength is tuned close to the transition between 1s^-1 3s and 1s^-1 3p (approximately 800nm). The minimum laser intensity required to observe EIT is of the order of 10^12 W/cm^2. The ab initio results are discussed in terms of an exactly solvable three-level model. This work opens new opportunities for research with ultrafast x-ray sources.

  20. Supernova remnants: the X-ray perspective

    Science.gov (United States)

    Vink, Jacco

    2012-12-01

    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 fresh nucleosynthesis, and resulted in the identification of regions near shock fronts that emit X-ray synchrotron radiation. Since X-ray synchrotron radiation requires 10-100 TeV electrons, which lose their energies rapidly, the study of X-ray synchrotron radiation has revealed those regions where active and rapid particle acceleration is taking place. In this text all the relevant aspects of X-ray emission from supernova remnants are reviewed and put into the context of supernova explosion properties and the physics and evolution of supernova remnants. The first half of this review has a more tutorial style and discusses the basics of supernova remnant physics and X-ray spectroscopy of the hot plasmas they contain. This includes hydrodynamics, shock heating, thermal conduction, radiation processes, non-equilibrium ionization, He-like ion triplet lines, and cosmic ray acceleration. The second half offers a review of the advances made in field of X-ray spectroscopy of supernova remnants during the last 15 year. This period coincides with the availability of X-ray imaging spectrometers. In addition, I discuss the results of high resolution X-ray spectroscopy with the Chandra and XMM-Newton gratings. Although these instruments are not ideal for studying extended sources, they nevertheless provided interesting results for a limited number of remnants. These results provide a glimpse of what may be achieved with future microcalorimeters that will be available on board future X-ray

  1. The quantum X-ray radiology apparatus

    CERN Document Server

    Hilt, B; Prevot, G

    2000-01-01

    The paper entitled 'New Quantum Detection System for Very Low Dose X-ray Radiology', presented at the talk session, discusses the preliminary data obtained using a new quantum X-ray radiology system with a high-efficiency solid-state detector and highly sensitive electronics, making it possible to reduce significantly the dose administered to a patient in X-ray radiology examinations. The present paper focuses more on the technological aspects of the apparatus, such as the integration of the detector with the two Asics, and the computer system. Namely, it is shown how the computer system calibrates the detection system, acquires the data in real time, and controls the scan parameters and image filtering process.

  2. Novel X-ray telescopes for wide-field X-ray monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Hudec, R. [Academy of science of Czech Republic, Ondrejov (Czech Republic); Inneman, A. [Centre for advanced X-ray technologies Reflex sro, Prague (Czech Republic); Pina, L.; Sveda, L. [Czech Technical Univ., Prague (Czech Republic). Faculty of Nuclear Science

    2005-07-15

    We report on fully innovative very wide-field of view X-ray telescopes with high sensitivity as well as large field of view. The prototypes are very promising, allowing the proposals for space projects with very wide-field Lobster-eye X-ray optics to be considered. The novel telescopes will monitor the sky with unprecedented sensitivity and angular resolution of order of 1 arcmin. They are expected to contribute essentially to study and to understand various astrophysical objects such as AGN, SNe, Gamma-ray bursts (GRBs), X-ray flashes (XRFs), galactic binary sources, stars, CVs, X-ray novae, various transient sources, etc. The Lobster optics based X-ray All Sky Monitor is capable to detect around 20 GRBs and 8 XRFs yearly and this will surely significantly contribute to the related science.

  3. Probing nucleobase photoprotection with soft x-rays

    Directory of Open Access Journals (Sweden)

    Osipov T.

    2013-03-01

    Full Text Available Nucleobases absorb strongly in the ultraviolet region, leading to molecular excitation into reactive states. The molecules avoid the photoreactions by funnelling the electronic energy into less reactive states on an ultrafast timescale via non-Born-Oppenheimer dynamics. Current theory on the nucleobase thymine discusses two conflicting pathways for the photoprotective dynamics. We present our first results of our free electron laser based UV-pump soft x-ray-probe study of the photoprotection mechanism of thymine. We use the high spatial sensitivity of the Auger electrons emitted after the soft x-ray pulse induced core ionization. Our transient spetra show two timescales on the order of 200 fs and 5 ps, in agreement with previous (all UV ultrafast experiments. The timescales appear at different Auger kinetic energies which will help us to decipher the molecular dynamics.

  4. Modern Developments in X-Ray and Neutron Optics

    CERN Document Server

    Erko, Alexei; Krist, Thomas; Michette, Alan G

    2008-01-01

    This volume describes modern developments in reflective, refractive and diffractive optics for short wavelength radiation as well as recent theoretical approaches to modelling and ray-tracing the X-ray and neutron optical systems. It is based on the joint research activities of specialists in X-ray and neutron optics from 11 countries, working together under the framework of the European Programme for Cooperation in Science and Technology (COST, Action P7) in the period 2002--2006. The chapters are written by leading specialists from European laboratories, universities and large facilities. In addition to new ideas and concepts, the contents provide a large amount of practical information about recently implemented devices and methods.

  5. Ultraluminous X-ray Sources in Interacting Galaxies

    CERN Document Server

    Swartz, Douglas A

    2009-01-01

    I give a brief review of how X-rays from nearby galaxies are used as direct tracers of recent star formation. This leads to the conclusion that it is the most luminous point-like sources that are associated with star formation and that the majority of these are high-mass X-ray binaries.I then discuss a recent study that shows that ULXs are preferentially found in regions as young as or younger than typical HII regions in their host galaxies. Finally, I describe a new study that attempts to determine the maximum luminosity of ULXs in the local universe by searching for them in interacting galaxies where the star formation rate is high.

  6. Active star-forming galaxies in the X ray foreground

    Science.gov (United States)

    Griffiths, R. E.; Padovani, P.

    1989-01-01

    Star forming galaxies were discovered as a component of the X-ray background (XRB) in the Einstein deep surveys. Such star forming galaxies may be largely powered by superluminous Population 1 massive X-ray binaries (MXRB), formed in the wake of star formation in regions of low metallicity. The star forming galaxies with moderate numbers of MXRB may evolve into the infrared starburst galaxies found at low redshifts using IRAS (Infrared Astronomy Satellite), and may also be related to those galaxies identified with sub-mJy radio sources. A conservative contribution to the XRB of at least approximately 15 percent, without evolution is estimated. It is shown that moderate evolution leads to a contribution at least equalling that of quasars. Above 3 keV, star forming galaxies may dominate the XRB.

  7. Tokamak Spectroscopy for X-Ray Astronomy

    Science.gov (United States)

    Fournier, Kevin B.; Finkenthal, M.; Pacella, D.; May, M. J.; Soukhanovskii, V.; Mattioli, M.; Leigheb, M.; Rice, J. E.

    2000-01-01

    This paper presents the measured x-ray and Extreme Ultraviolet (XUV) spectra of three astrophysically abundant elements (Fe, Ca and Ne) from three different tokamak plasmas. In every case, each spectrum touches on an issue of atomic physics that is important for simulation codes to be used in the analysis of high spectral resolution data from current and future x-ray telescopes. The utility of the tokamak as a laboratory test bed for astrophysical data is demonstrated. Simple models generated with the HULLAC suite of codes demonstrate how the atomic physics issues studied can affect the interpretation of astrophysical data.

  8. European XFEL: Soft X-Ray instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Molodtsov, S. L., E-mail: serguei.molodtsov@xfel.eu [European XFEL GmbH (Germany)

    2011-12-15

    The currently constructed European X-Ray Free Electron Laser (XFEL) will generate new knowledge in almost all the technical and scientific disciplines that are shaping our daily life-including nanotechnology, medicine, pharmaceutics, chemistry, materials science, power engineering and electronics. On 8 January 2009, civil engineering work (tunnels, shafts, halls) has been started at all three construction sites. In this presentation status and parameters of the European XFEL facility and instrumentation as well as planned research applications particularly in the range of soft X-rays are reviewed.

  9. Imaging plates calibration to X-rays

    Science.gov (United States)

    Curcio, A.; Andreoli, P.; Cipriani, M.; Claps, G.; Consoli, F.; Cristofari, G.; De Angelis, R.; Giulietti, D.; Ingenito, F.; Pacella, D.

    2016-05-01

    The growing interest for the Imaging Plates, due to their high sensitivity range and versatility, has induced, in the last years, to detailed characterizations of their response function in different energy ranges and kind of radiation/particles. A calibration of the Imaging Plates BAS-MS, BAS-SR, BAS-TR has been performed at the ENEA-Frascati labs by exploiting the X-ray fluorescence of different targets (Ca, Cu, Pb, Mo, I, Ta) and the radioactivity of a BaCs source, in order to cover the X-ray range between few keV to 80 keV.

  10. Single Particle X-ray Diffractive Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Bogan, M J; Benner, W H; Boutet, S; Rohner, U; Frank, M; Seibert, M; Maia, F; Barty, A; Bajt, S; Riot, V; Woods, B; Marchesini, S; Hau-Riege, S P; Svenda, M; Marklund, E; Spiller, E; Hajdu, J; Chapman, H N

    2007-10-01

    In nanotechnology, strategies for the creation and manipulation of nanoparticles in the gas phase are critically important for surface modification and substrate-free characterization. Recent coherent diffractive imaging with intense femtosecond X-ray pulses has verified the capability of single-shot imaging of nanoscale objects at sub-optical resolutions beyond the radiation-induced damage threshold. By intercepting electrospray-generated particles with a single 15 femtosecond soft-X-ray pulse, we demonstrate diffractive imaging of a nanoscale specimen in free flight for the first time, an important step toward imaging uncrystallized biomolecules.

  11. Radiobiological studies using gamma and x rays.

    Energy Technology Data Exchange (ETDEWEB)

    Potter, Charles Augustus; Longley, Susan W.; Scott, Bobby R.; Lin, Yong; Wilder, Julie; Hutt, Julie A.; Padilla, Mabel T.; Gott, Katherine M.

    2013-02-01

    There are approximately 500 self-shielded research irradiators used in various facilities throughout the U.S. These facilities use radioactive sources containing either 137Cs or 60Co for a variety of biological investigations. A report from the National Academy of Sciences[1] described the issues with security of particular radiation sources and the desire for their replacement. The participants in this effort prepared two peer-reviewed publications to document the results of radiobiological studies performed using photons from 320-kV x rays and 137Cs on cell cultures and mice. The effectiveness of X rays was shown to vary with cell type.

  12. Effects of X-Ray Dose On Rhizosphere Studies Using X-Ray Computed Tomography.

    Directory of Open Access Journals (Sweden)

    Susan Zappala

    Full Text Available 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 as root washing. However, one routinely unreported aspect of X-ray CT is the potential effect of X-ray dose on the soil-borne microorganisms and plants in rhizosphere investigations. Here we aimed to i highlight the need for more consistent reporting of X-ray CT parameters for dose to sample, ii to provide an overview of previously reported impacts of X-rays on soil microorganisms and plant roots and iii present new data investigating the response of plant roots and microbial communities to X-ray exposure. Fewer than 5% of the 126 publications included in the literature review contained sufficient information to calculate dose and only 2.4% of the publications explicitly state an estimate of dose received by each sample. We conducted a study involving rice roots growing in soil, observing no significant difference between the numbers of root tips, root volume and total root length in scanned versus unscanned samples. In parallel, a soil microbe experiment scanning samples over a total of 24 weeks observed no significant difference between the scanned and unscanned microbial biomass values. We conclude from the literature review and our own experiments that X-ray CT does not impact plant growth or soil microbial populations when employing a low level of dose (<30 Gy. However, the call for higher throughput X-ray CT means that doses that biological samples receive are likely to increase and thus should be closely monitored.

  13. 20 CFR 718.102 - Chest roentgenograms (X-rays).

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Chest roentgenograms (X-rays). 718.102... roentgenograms (X-rays). (a) A chest roentgenogram (X-ray) shall be of suitable quality for proper classification...-rays as described in Appendix A. (b) A chest X-ray to establish the existence of pneumoconiosis...

  14. Differential phase contrast X-ray imaging system and components

    Science.gov (United States)

    Stutman, Daniel; Finkenthal, Michael

    2014-07-01

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

  15. Differential phase contrast X-ray imaging system and components

    Energy Technology Data Exchange (ETDEWEB)

    Stutman, Daniel; Finkenthal, Michael

    2017-01-31

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

  16. Pushing the Boundaries of Suborbital Soft X-ray Spectroscopy

    Science.gov (United States)

    McEntaffer, Randall

    optics are planned for every future large X-ray mission and flight-proving the design is extremely important. The gratings will be radially grooved and blazed to reduce grating aberrations and to focus the spectrum to one side of zero-order. Gratings of this type have been well developed by the IXO Off- Plane X-ray Grating Spectrometer concept study, but have not been flight proven. The spectrum will be focused onto high spatial resolution CCD detectors. OGRE will draw heavily from the heritage gained from OGRESS. OGRE will observe Capella. Due to its high flux and spectral line density, Capella is an ideal target for showcasing the resolution capabilities of our instrument. As an important calibration target, our improved resolution measurements will be extremely helpful for many future X-ray observations. OGRESS has already provided three thesis projects for past graduate students. The upgrades and flights proposed here will produce at least two more PhD theses. This program in hands-on training of young scientists in the techniques of instrumental X-ray astronomy has proven very successful over nearly three decades, leading to high rates of launch, publication, graduation, and flight qualification of instrumental PI's. It will also provide full experiment cycle experience - design, fabrication, tolerancing, assembly, flight-qualification, calibration, integration, launch, and data analysis - with reflection gratings, GEM and CCD detectors, and other technologies suitable for adaptation to NASA's major missions. The University of Iowa and University of Colorado programs in suborbital X-ray astronomy represent an exciting mix of compelling science, cutting- edge technology development, and training of young scientists.

  17. X-ray diffraction from single GaAs nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Biermanns, Andreas

    2012-11-12

    In recent years, developments in X-ray focussing optics have allowed to produce highly intense, coherent X-ray beams with spot sizes in the range of 100 nm and below. Together with the development of new experimental stations, X-ray diffraction techniques can now be applied to study single nanometer-sized objects. In the present work, X-ray diffraction is applied to study different aspects of the epitaxial growth of GaAs nanowires. Besides conventional diffraction methods, which employ X-ray beams with dimensions of several tens of {mu}m, special emphasis lies on the use of nanodiffraction methods which allow to study single nanowires in their as-grown state without further preparation. In particular, coherent X-ray diffraction is applied to measure simultaneously the 3-dimensional shape and lattice parameters of GaAs nanowires grown by metal-organic vapor phase epitaxy. It is observed that due to a high density of zinc-blende rotational twins within the nanowires, their lattice parameter deviates systematically from the bulk zinc-blende phase. In a second step, the initial stage in the growth of GaAs nanowires on Si (1 1 1) surfaces is studied. This nanowires, obtained by Ga-assisted growth in molecular beam epitaxy, grow predominantly in the cubic zinc-blende structure, but contain inclusions of the hexagonal wurtzite phase close to their bottom interface. Using nanodiffraction methods, the position of the different structural units along the growth axis is determined. Because the GaAs lattice is 4% larger than silicon, these nanowires release their lattice mismatch by the inclusion of dislocations at the interface. Whereas NWs with diameters below 50 nm are free of strain, a rough interface structure in nanowires with diameters above 100 nm prevents a complete plastic relaxation, leading to a residual strain at the interface that decays elastically along the growth direction. Finally, measurements on GaAs-core/InAs-shell nanowire heterostructures are presented

  18. Towards laboratory x-ray nanotomography: instrumental improvements on a SEM-based system

    Science.gov (United States)

    Gomes Perini, L. A.; Bleuet, P.; Buijsse, B.; Kwakman, L. F. Tz.; Parker, W.

    2016-10-01

    We aim at resolving deca-nanometer features in microelectronic samples using a laboratory SEM-based X-ray tomography microscope. Such a system produces X-rays through the interaction between a focused SEM electron beam and a metallic target. The effective source size of the X-ray beam can be adjusted by varying the target material and geometry. For instance, the use of tungsten nanowires (few hundred nanometers of length) combined with a high electron beam current leads to an increased X-ray flux generated in a reduced volume, necessary for detecting interface details of the analyzed object. It improves resolution and signal-to-noise ratio (SNR), but is also sensitive to electron beam-target instabilities during the scan. To improve robustness, a FFT-based image correlation is integrated in the process through a closed-loop control scheme. It allows stabilizing the electron beam on the target and to preserve the X-ray flux intensity and alignment. Also, a state of the art high-resolution scientific-CMOS (sCMOS) X-ray detector was installed, allowing to reduce noise and to increase quantum efficiency. Results show that such numerical and equipment improvements lead to significant gains in spatial resolution, SNR and scanning time of the SEM-based tomography. It paves the way to routine, high resolution, 3D X-ray imaging in the laboratory.

  19. The Physical Basis of the LX = Lbol Empirical Law for O-Star X-Rays

    Science.gov (United States)

    Owocki, S. P.; Sundqvist, J. O.; Cohen, D. H.; Gayley, K. G.

    2012-12-01

    X-ray satellites since Einstein have empirically established that the X-ray luminosity from single O-stars scales linearly with bolometric luminosity, LX = 10-7 Lbol. But straightforward forms of the most favored model, in which X-rays arise from instability-generated shocks embedded in the stellar wind, predict a steeper scaling, either with mass-loss rate LX = M = Lbol1.7 if the shocks are radiative, or with LX = M2 = Lbol3.4 if they are adiabatic. We present here a generalized formalism that bridges these radiative vs. adiabatic limits in terms of the ratio of the shock cooling length to the local radius. Noting that the thin-shell instability of radiative shocks should lead to extensive mixing of hot and cool material, we then propose that the associated softening and weakening of the X-ray emission can be parameterized by the cooling length ratio raised to a power m, the “mixing exponent". For physically reasonable values m ≍ 0.4, this leads to an X-ray luminosity LX = M0.6 = Lbol that matches the empirical scaling. We conclude by noting that such thin-shell mixing may also be important for X-rays from colliding wind binaries, and that future numerical simulation studies will be needed to test this thin-shell mixing ansatz for X-ray emission.

  20. Polymer Compund Refractive Lenses for Hard X-ray Nanofocusing

    OpenAIRE

    Krywka, Christina; Last, Arndt; Marschall, Felix; Markus, Otto; Georgi, Sebastian; Mueller, Martin; Mohr, Jürgen

    2016-01-01

    Compound refractive lenses fabricated out of SU-8 negative photoresist have been used to generate a nanofocused, i.e. sub-μm sized X-ray focal spot at an X-ray nanodiffraction setup. X-ray microscopy and X-ray diffraction techniques have conceptually different demands on nanofocusing optical elements and so with the application of X-ray nanodiffraction in mind, this paper presents the results of an initial characterization of polymer lenses used as primary focusin...

  1. An X-ray and optical study of the ultracompact X-ray binary A 1246-58

    NARCIS (Netherlands)

    in 't Zand, J. J. M.; Bassa, C. G.; Keek, L.; Verbunt, F.; Mendez, M.; Markwardt, C. B.; Jonker, P.G.

    2008-01-01

    Results are discussed of an X-ray and optical observation campaign of the low-mass X-ray binary A 1246-58 performed with instruments on Satellite per Astronomia X ("BeppoSAX"), the Rossi X-ray Timing Explorer (RXTE), the X-ray Multi-mirror Mission ("XMM-Newton"), the Swift mission, and the Very Larg

  2. An X-ray and optical study of the ultracompact X-ray binary A1246-58

    NARCIS (Netherlands)

    Zand, J. J. M. in 't

    2008-01-01

    Results are discussed of an X-ray and optical observation campaign of the low-mass X-ray binary A 1246-58 performed with instruments on Satellite per Astronomia X (’BeppoSAX’), the Rossi X-ray Timing Explorer (RXTE), the X-ray Multi-mirror Mission (’XMM-Newton’), the Swift mission, and the Very Larg

  3. Optical and X-ray monitoring of the NLS1 galaxy Ark 564

    CERN Document Server

    Papadakis, I E; Negoro, H; Detsis, E; Papamastorakis, J; Gliozzi, M

    2000-01-01

    The Narrow-line Seyfert galaxy Ark 564 was monitored between June 04, 2000 and June 24, 2000 from Skinakas Observatory. The B,V,R and I band light curves show night to night variations of 0.1 mag. Comparison with X-ray data from a simultaneous ASCA observation shows that the X-ray variations are more pronounced than in the optical band. Cross correlation analysis yields a time lag of ~ 0.8 days in the sense that the X-rays are leading the optical but with low statistical significance. We discuss possible implications of our results to current physical models of AGN.

  4. Feasibility study of total reflection X-ray fluorescence analysis using a liquid metal jet X-ray tube

    Energy Technology Data Exchange (ETDEWEB)

    Maderitsch, A.; Smolek, S. [Atominstitut, Vienna University of Technology, Stadionallee 2, 1020 Wien (Austria); Wobrauschek, P., E-mail: wobi@ati.ac.at [Atominstitut, Vienna University of Technology, Stadionallee 2, 1020 Wien (Austria); Streli, C. [Atominstitut, Vienna University of Technology, Stadionallee 2, 1020 Wien (Austria); Takman, P. [Excillum AB, Finlandsgatan 14, 164 74 Kista (Sweden)

    2014-09-01

    Total reflection X-ray spectroscopy (TXRF) is a powerful analytical technique for qualitative and quantitative analysis of trace and ultratrace elements in a sample with lower limits of detection (LLDs) of pg/g to ng/g in concentration and absolute high fg levels are attainable. Several X-ray sources, from low power (few W), 18 kW rotating anodes to synchrotron radiation, are in use for the excitation and lead accordingly to their photon flux delivered on the sample the detection limits specified. Not only the power, but also the brilliance and focal shape are of importance for TXRF. A microfocus of 50–100 μm spot size or the line focus of diffraction tubes is best suited. Excillum developed a new approach in the design of a source: the liquid metal jet anode. In this paper the results achieved with this source are described. A versatile TXRF spectrometer with vacuum chamber designed at Atominstitut was used for the experiments. A multilayer monochromator selecting the intensive Ga-Kα radiation was taken and the beam was collimated by 50 μm slits. Excellent results regarding geometric beam stability, high fluorescence intensities and low background were achieved leading to detection limits in the high fg range for Ni. A 100 mm{sup 2} silicon drift detector (SDD) collimated to 80 mm{sup 2} was used to collect the fluorescence radiation. The results from measurements on single element samples are presented. - Highlights: • Using a new X-ray source for TXRF • Liquid metal jet X-ray source from Excillum • Offers improvements for lab based TXRF spectrometers • Can also be important for related techniques.

  5. 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.

  6. Spectroscopy and X-Ray Astronomy

    Science.gov (United States)

    Holt, Stephen S.

    2000-01-01

    The new x-ray astronomical observatories have sufficient spectroscopic capability to allow the determination of plasma conditions in the form of velocities, temperatures, densities, and turbulence parameters at levels that were previously unattainable. The utilization of these diagnostics are possible only if the atomic and plasma physics are well-enough understood to match the observational sensitivity.

  7. X-ray emission from red quasars

    Science.gov (United States)

    Bregman, J. N.; Glassgold, A. E.; Huggins, P. J.; Kinney, A. L.

    1985-01-01

    A dozen red quasars were observed with the Einstein Observatory in order to determine their X-ray properties. The observations show that for all these sources, the infrared-optical continuum is so steep that when extrapolated to higher frequencies, it passes orders of magnitude below the measured X-ray flux. The X-ray emission is better correlated with the radio than with the infrared flux, suggesting a connection between the two. By applying the synchrotron-self-Compton model to the data, it is found that the infrared-optical region has a size of 0.01 pc or more and a magnetic field more than 0.1 G, values considerably different than are found in the radio region. Unlike other quasars, the ionizing continuum is dominated by the X-ray emission. The peculiar line ratios seen in these objects can be understood with a photoionization model, provided that the photon to gas density ratio (ionization parameter) is an order of magnitude less than in typical quasars.

  8. Reconstructing misaligned x-ray CT data

    Energy Technology Data Exchange (ETDEWEB)

    Divin, C. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-10-24

    Misalignment errors for x-ray computed tomography (CT) systems can manifest as artifacts and a loss of spatial and contrast resolution. To mitigate artifacts, significant effort is taken to determine the system geometry and minimizing any residual error in the system alignment. This project improved our ability to post-correct data which was acquired on a misaligned CT system.

  9. X-ray voltabsorptometry on redox proteins

    Energy Technology Data Exchange (ETDEWEB)

    Ascone, Isabella [Dipartimento di Fisica, Universita di Roma ' La Sapienza' , P.le A. Moro 5, 00185 Rome (Italy) and LURE/CNRS Centre Universitaire Paris-Sud, bat. 209 D, B.P. 34, 91898 Orsay Cedex (France)]. E-mail: i.ascone@caspur.it; Zamponi, Silvia [Dipartimento di Scienze Chimiche, Universita di Camerino, Via S. Agostino 1, 62032 Camerino (Italy); Cognigni, Andrea [LURE/CNRS Centre Universitaire Paris-Sud, bat. 209 D, B.P. 34, 91898 Orsay Cedex (France); Marmocchi, Franco [Dipartimento di Biologia Molecolare, Cellulare e Animale, Universita di Camerino, Via Camerini, 1 Camerino (Italy); Marassi, Roberto [Dipartimento di Scienze Chimiche, Universita di Camerino, Via S. Agostino 1, 62032 Camerino (Italy)

    2005-04-15

    Biological X-ray absorption spectroscopy (BioXAS) is able to describe the metal environment in a metalloprotein and is sensitive to metal oxidation state. Coupling of BioXAS and electrochemistry permits the characterization of different oxidation states and avoids uncontrolled protein redox state changes due to X-ray beam irradiation. XAS spectroelectrochemistry requires electrochemical cells specifically designed to meet the requirements of both XAS measurements and electrochemical effectiveness in potential control. In this context, this paper describes a new cell tested with different types of working electrodes developed for BioXAS, in particular for in situ studies of redox proteins. The XAS electrochemical measurements of a relatively high-molecular-weight protein (Cu,Zn superoxide dismutase) for which it is difficult to observe direct electrochemistry have been achieved. New working electrodes, capable of fast and unmediated electron transfer, are described. The cell permits to isolate protein redox states and to measure X-ray absorption intensity during a potential scan (X-ray voltabsorptometry)

  10. Outbursts in ultracompact X-ray binaries

    CERN Document Server

    Hameury, J -M

    2016-01-01

    Very faint X-ray binaries appear to be transient in many cases with peak luminosities much fainter than that of usual soft X-ray transients, but their nature still remains elusive. We investigate the possibility that this transient behaviour is due to the same thermal/viscous instability which is responsible for outbursts of bright soft X-ray transients, occurring in ultracompact binaries for adequately low mass-transfer rates. More generally, we investigate the observational consequences of this instability when it occurs in ultracompact binaries. We use our code for modelling the thermal-viscous instability of the accretion disc, assumed here to be hydrogen poor. We also take into account the effects of disc X-ray irradiation, and consider the impact of the mass-transfer rate on the outburst brightness. We find that one can reproduce the observed properties of both the very faint and the brighter short transients (peak luminosity, duration, recurrence times), provided that the viscosity parameter in quiesce...

  11. Supernova remnants: the X-ray perspective

    NARCIS (Netherlands)

    Vink, J.

    2012-01-01

    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 i

  12. Fourier techniques in X-ray timing

    NARCIS (Netherlands)

    M. van der Klis

    1988-01-01

    Basic principles of Fourier techniques often used in X-ray time series analysis are reviewed. The relation between the discrete Fourier transform and the continuous Fourier transform is discussed to introduce the concepts of windowing and aliasing. The relation is derived between the power spectrum

  13. X-ray spectroscopy of manganese clusters

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-06-01

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

  14. X-Ray Diffraction Analysis Program

    Science.gov (United States)

    Wiedemann, K. E.; Unnam, J.; Naidu, S. V. N.; Houska, C. R.

    1986-01-01

    SOPAD separates overlapping peaks and analyzes derivatives of X-ray diffraction data. SOPAD helps analyst get most information out of available diffraction data. SOPAD uses Marquardt-type nonlinear regression routine to refine initial estimates of individual peak positions, intensities, shapes, and half-widths.

  15. Neutron and X-ray Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Carini, Gabriella [SLAC National Accelerator Lab., Menlo Park, CA (United States); Denes, Peter [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Gruener, Sol [Cornell Univ., Ithaca, NY (United States); Lessner, Elianne [Dept. of Energy (DOE), Washington DC (United States). Office of Science Office of Basic Energy Sciences

    2012-08-01

    The Basic Energy Sciences (BES) X-ray and neutron user facilities attract more than 12,000 researchers each year to perform cutting-edge science at these state-of-the-art sources. While impressive breakthroughs in X-ray and neutron sources give us the powerful illumination needed to peer into the nano- to mesoscale world, a stumbling block continues to be the distinct lag in detector development, which is slowing progress toward data collection and analysis. Urgently needed detector improvements would reveal chemical composition and bonding in 3-D and in real time, allow researchers to watch “movies” of essential life processes as they happen, and make much more efficient use of every X-ray and neutron produced by the source The immense scientific potential that will come from better detectors has triggered worldwide activity in this area. Europe in particular has made impressive strides, outpacing the United States on several fronts. Maintaining a vital U.S. leadership in this key research endeavor will require targeted investments in detector R&D and infrastructure. To clarify the gap between detector development and source advances, and to identify opportunities to maximize the scientific impact of BES user facilities, a workshop on Neutron and X-ray Detectors was held August 1-3, 2012, in Gaithersburg, Maryland. Participants from universities, national laboratories, and commercial organizations from the United States and around the globe participated in plenary sessions, breakout groups, and joint open-discussion summary sessions. Sources have become immensely more powerful and are now brighter (more particles focused onto the sample per second) and more precise (higher spatial, spectral, and temporal resolution). To fully utilize these source advances, detectors must become faster, more efficient, and more discriminating. In supporting the mission of today’s cutting-edge neutron and X-ray sources, the workshop identified six detector research challenges

  16. X-ray scattering from liquid interfaces

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Synchrotron radiation X-ray scattering is a useful tool for structural characterization of liquid interfaces.Specular refiectivity provides precise measurement of the interfacial widths and of the ordering of surfactants adsorbed to these interfaces. Diffuse scattering gives information on phase transitions and domain formation in surfactant monolayers and on interfacial fluctuations confined by and coupled across fluidic films.

  17. 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 pri......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-rays (wavelength around 2 A) since they match the absorption edges of sulfur and chlorine....... A 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...

  18. Hard x-ray telescope mission

    DEFF Research Database (Denmark)

    Gorenstein, P.; Worrall, D.; Joensen, K.D.

    1996-01-01

    The Hard X-Ray Telescope was selected for study as a possible new intermediate size mission for the early 21st century. Its principal attributes are: (1) multiwavelength observing with a system of focussing telescopes that collectively observe from the UV to over 1 MeV, (2) much higher sensitivity...

  19. X-ray microscopy of human malaria

    Energy Technology Data Exchange (ETDEWEB)

    Magowan, C.; Brown, J.T.; Mohandas, N.; Meyer-Ilse, W. [Ernest Orlando Lawrence Berkeley National Lab., CA (United States)

    1997-04-01

    Associations between intracellular organisms and host cells are complex and particularly difficult to examine. X-ray microscopy provides transmission images of subcellular structures in intact cells at resolutions superior to available methodologies. The spatial resolution is 50-60nm with a 1 micron depth of focus, superior to anything achievable with light microscopy. Image contrast is generated by differences in photoelectric absorption by the atoms in different areas (i.e. subcellular structures) throughout the full thickness of the sample. Absorption due to carbon dominates among all the elements in the sample at 2.4 nm x-ray wavelength. Thus images show features or structures, in a way not usually seen by other types of microscopy. The authors used soft x-ray microscopy to investigate structural development of Plasmodium falciparum malaria parasites in normal and genetically abnormal erythrocytes, and in infected erythrocytes treated with compounds that have anti-malarial effects. X-ray microscopy showed newly elaborated structures in the cytosol of unstained, intact erythrocytes, redistribution of mass (carbon) in infected erythrocytes, and aberrant parasite morphology. Better understanding of the process of intracellular parasite maturation and the interactions between the parasite and its host erythrocyte can help define new approaches to the control of this deadly disease.

  20. X-ray holography with atomic resolution

    Science.gov (United States)

    Tegze, Miklós; Faigel, Gyula

    1996-03-01

    DIFFRACTION methods for crystallographic structure determination suffer from the so-called 'phase problem'; a diffraction pattern provides intensity but not phase information for the scattered beams, and therefore cannot be uniquely inverted to obtain the crystal structure of a sample. Holographic methods1, on the other hand, offer a means of extracting both intensity and phase information. To be useful for crystallographic applications, holography must be implemented with radiation of sufficiently small wavelength to resolve atomic-scale features2. One method, electron-emission holography3-9, uses electron waves and is a powerful tool for studying surface structure; but it cannot image the internal structure of solids because of complications arising from the highly anisotropic nature of electron scattering processes. A proposed alternative method uses X-rays2,10-13, which scatter more isotropically than electrons. Here we demonstrate the efficacy of atomic-scale X-ray holography by obtaining direct images of the three-dimensional arrangement of strontium atoms in the cubic perovskite SrTiO3. With more intense synchrotron sources for illumination, and with the development of improved X-ray detectors, X-ray holography should become a powerful general technique for unambiguous structure determination in condensed matter systems.

  1. Soft X-ray follow-up of five hard X-ray emitters

    CERN Document Server

    Pavan, L; Ferrigno, C; Falanga, M; Campana, S; Paltani, S; Stella, L; Walter, R

    2013-01-01

    We studied the soft-X-ray emission of five hard-X sources: IGR J08262-3736, IGR J17354-3255, IGR J16328-4726, SAX J1818.6-1703 and IGR J17348-2045. These sources are: a confirmed supergiant high mass X-ray binary (IGR J08262-3736); candidates (IGR J17354-3255, IGR J16328- 4726) and confirmed (SAX J1818.6-1703) supergiant fast X-ray transients; IGR J17348-2045 is one of the as-yet unidentified objects discovered with INTEGRAL. Thanks to dedicated XMM-Newton observations, we obtained the first detailed soft X-ray spectral and timing study of IGR J08262-3736. The results obtained from the observations of IGR J17354-3255 and IGR J16328-4726 provided further support in favor of their association with the class of Supergiant Fast X-ray Transients. SAX J1818.6-1703, observed close to phase 0.5, was not detected by XMM-Newton, thus supporting the idea that this source reaches its lowest X-ray luminosity (~10^32 erg/s) around apastron. For IGR J17348-2045 we identified for the first time the soft X-ray counterpart and...

  2. X-ray Chirped Pulse Amplification: towards GW Soft X-ray Lasers

    Directory of Open Access Journals (Sweden)

    Marta Fajardo

    2013-07-01

    Full Text Available Extensive modeling of the seeding of plasma-based soft X-ray lasers is reported in this article. Seminal experiments on amplification in plasmas created from solids have been studied in detail and explained. Using a transient collisional excitation scheme, we show that a 18 µJ, 80 fs fully coherent pulse is achievable by using plasmas pumped by a compact 10 Hz laser. We demonstrate that direct seeding of plasmas created by nanosecond lasers is not efficient. Therefore, we propose and fully study the transposition to soft X-rays of the Chirped Pulse Amplification (CPA technique. Soft X-ray pulses with energy of 6 mJ and 200 fs duration are reachable by seeding plasmas pumped by compact 100 J, sub-ns, 1 shot/min lasers. These soft X-ray lasers would reach GW power, corresponding to an increase of 100 times as compared to the highest peak power achievable nowadays in the soft X-ray region (30 eV–1 keV. X-ray CPA is opening new horizon for soft x-ray ultra-intense sources.

  3. Three dimensional subsurface elemental identification of minerals using confocal micro-X-ray fluorescence and micro-X-ray computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Cordes, Nikolaus L., E-mail: ncordes@lanl.gov [Polymers and Coatings Group, Material Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Seshadri, Srivatsan, E-mail: srivatsan.seshadri@zeiss.com [Carl Zeiss X-ray Microscopy, Inc., Pleasanton, CA 94588 (United States); Havrilla, George J. [Chemical Diagnostics and Engineering, Chemistry Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Yuan, Xiaoli [Julius Kruttschnitt Mineral Research Centre, University of Queensland, Indooroopilly, Brisbane, QLD 4068 (Australia); Feser, Michael [Carl Zeiss X-ray Microscopy, Inc., Pleasanton, CA 94588 (United States); Patterson, Brian M. [Polymers and Coatings Group, Material Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2015-01-01

    Current non-destructive elemental characterization methods, such as scanning electron microscopy-based energy dispersive spectroscopy (SEM–EDS) and micro-X-ray fluorescence spectroscopy (MXRF), are limited to either elemental identification at the surface (SEM–EDS) or suffer from an inability to discriminate between surface or depth information (MXRF). Thus, a non-destructive elemental characterization of individual embedded particles beneath the surface is impossible with either of these techniques. This limitation can be overcome by using laboratory-based 3D confocal micro-X-ray fluorescence spectroscopy (confocal MXRF). This technique utilizes focusing optics on the X-ray source and detector which allows for spatial discrimination in all three dimensions. However, the voxel-by-voxel serial acquisition of a 3D elemental scan can be very time-intensive (~ 1 to 4 weeks) if it is necessary to locate individual embedded particles of interest. As an example, if each point takes a 5 s measurement time, a small volume of 50 × 50 × 50 pixels leads to an acquisition time of approximately 174 h, not including sample stage movement time. Initially screening the samples for particles of interest using micro-X-ray computed tomography (micro-CT) can significantly reduce the time required to spatially locate these particles. Once located, these individual particles can be elementally characterized with confocal MXRF. Herein, we report the elemental identification of high atomic number surface and subsurface particles embedded in a mineralogical matrix by coupling micro-CT and confocal MXRF. Synergistically, these two X-ray based techniques first rapidly locate and then elementally identify individual subsurface particles. - Highlights: • Coupling of confocal X-ray fluorescence spectroscopy and X-ray computed tomography • Qualitative elemental identification of surface and subsurface mineral particles • Non-destructive particle size measurements • Utilization of

  4. Liquid explosions induced by X-ray laser pulses

    Science.gov (United States)

    Stan, Claudiu; Laksmono, Hartawan; Sierra, Raymond; McQueen, Trevor; Milathianaki, Despina; Koglin, Jason; Lane, Thomas; Messerschmidt, Marc; Williams, Garth; Hayes, Matt; Guillet, Serge; Botha, Sabine; Nass, Karol; Schlichting, Ilme; Shoeman, Robert; Stone, Howard; Boutet, Sébastien

    2015-11-01

    Sudden generation and release of enough energy to vaporize matter are encountered in systems that range from supernovae explosions and asteroid impacts to applications in fusion energy generation, materials processing, and laser surgery. Understanding these strong explosions is important to both fundamental science and technical applications. We studied a new type of microexplosion, induced by absorption of X-ray pulses from a free-electron laser in micron-sized drops and jets of water. These explosions are related to, but different from, those observed in experiments performed with optical lasers. Unlike explosions caused by optical lasers, X-ray laser explosions produce symmetric expansion patterns that are simpler to rationalize. The release of energy initially concentrated in a small region inside drops and jets leads to ballistic vapor flow and inertial liquid flow. The kinematics of these flows indicates that the conversion of the energy deposited by X-rays into flow has a scaling that is similar to the one encountered in shock waves.

  5. Deterministic Chaos in the X-ray Sources

    Science.gov (United States)

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

    2015-12-01

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

  6. X-ray Synchrotron Radiation in a Plasma Wiggler

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Shuoquin; /UCLA /SLAC, SSRL

    2005-09-27

    A relativistic electron beam can radiate due to its betatron motion inside an ion channel. The ion channel is induced by the electron bunch as it propagates through an underdense plasma. In the theory section of this thesis the formation of the ion channel, the trajectories of beam electrons inside the ion channel, the radiation power and the radiation spectrum of the spontaneous emission are studied. The comparison between different plasma wiggler schemes is made. The difficulties in realizing stimulated emission as the beam traverses the ion channel are investigated, with particular emphasis on the bunching mechanism, which is important for the ion channel free electron laser. This thesis reports an experiment conducted at the Stanford Linear Accelerator Center (SLAC) to measure the betatron X-ray radiations for the first time. They first describe the construction and characterization of the lithium plasma source. In the experiment, the transverse oscillations of the SLAC 28.5 GeV electron beam traversing through a 1.4 meter long lithium plasma source are clearly seen. These oscillations lead to a quadratic density dependence of the spontaneously emitted betatron X-ray radiation. The divergence angle of the X-ray radiation is measured. The absolute photon yield and the spectral brightness at 14.2 KeV photon energy are estimated and seen to be in reasonable agreement with theory.

  7. 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...

  8. An Observational Diagnostic for Ultraluminous X-Ray Sources

    CERN Document Server

    Kalogera, V; Ivanova, N; King, A R

    2004-01-01

    We consider observational tests for the nature of Ultraluminous X-ray sources (ULXs). These must distinguish between thermal-timescale mass transfer on to stellar-mass black holes leading to anisotropic X-ray emission, and accretion on to intermediate-mass black holes. We suggest that long-term transient behavior via the thermal-viscous disk instability could discriminate between these two possibilities for ULXs in regions of young stellar populations. Thermal-timescale mass transfer generally produces stable disks and persistent X-ray emission. In contrast, mass transfer from massive stars to black holes produces unstable disks and thus transient behavior, provided that the black hole mass exceeds some minimum value. This minimum mass depends primarily on the donor mass and evolutionary state. We show that it exceeds 50 solar masses for a large fraction (greater than 90%) of the mass-transfer lifetime for the most likely donors in young clusters. Thus if long-term monitoring reveals a large transient fractio...

  9. Turbulent heating in galaxy clusters brightest in X-rays.

    Science.gov (United States)

    Zhuravleva, I; Churazov, E; Schekochihin, A A; Allen, S W; Arévalo, P; Fabian, A C; Forman, W R; Sanders, J S; Simionescu, A; Sunyaev, R; Vikhlinin, A; Werner, N

    2014-11-06

    The hot (10(7) to 10(8) kelvin), X-ray-emitting intracluster medium (ICM) is the dominant baryonic constituent of clusters of galaxies. In the cores of many clusters, radiative energy losses from the ICM occur on timescales much shorter than the age of the system. Unchecked, this cooling would lead to massive accumulations of cold gas and vigorous star formation, in contradiction to observations. Various sources of energy capable of compensating for these cooling losses have been proposed, the most promising being heating by the supermassive black holes in the central galaxies, through inflation of bubbles of relativistic plasma. Regardless of the original source of energy, the question of how this energy is transferred to the ICM remains open. Here we present a plausible solution to this question based on deep X-ray data and a new data analysis method that enable us to evaluate directly the ICM heating rate from the dissipation of turbulence. We find that turbulent heating is sufficient to offset radiative cooling and indeed appears to balance it locally at each radius-it may therefore be the key element in resolving the gas cooling problem in cluster cores and, more universally, in the atmospheres of X-ray-emitting, gas-rich systems on scales from galaxy clusters to groups and elliptical galaxies.

  10. Laser-driven soft-X-ray undulator source

    Energy Technology Data Exchange (ETDEWEB)

    Fuchs, Matthias

    2010-08-04

    The experimental results described in this thesis demonstrate the successful synergy between the research fields described above: the development of an undulator source driven by laser-plasma accelerated electron beams. First efforts in this new field have led to the production of radiation in the visible to infrared part of the electromagnetic spectrum [Schlenvoigt et al., 2008]. In contrast to these early achievements, the experiment described here shows the successful production of laser-driven undulator radiation in the soft-X-ray range with a remarkable reproducibility. The source produced tunable, collimated beams with a wavelength of {proportional_to}17 nm from a compact setup. Undulator spectra were detected in {proportional_to}70% of consecutive driver-laser shots, which is a remarkable reproducibility for a first proof-of-concept demonstration using ultra-high intensity laser systems. This can be attributed to a stable electron acceleration scheme as well as to the first application of miniature magnetic quadrupole lenses with laseraccelerated beams. The lenses significantly reduce the electron beam divergence and its angular shot-to-shot fluctuations The setup of this experiment is the foundation of potential university-laboratory-sized, highly-brilliant hard X-ray sources. By increasing the electron energy to about 1 GeV, X-ray pulses with an expected duration of {proportional_to}10 fs and a photon energy of 1 keV could be produced in an almost identical arrangement. It can also be used as a testbed for the development of a free-electron laser of significantly smaller dimension than facilities based on conventional accelerators [Gruener et al., 2007]. Such compact sources have the potential for application in many fields of science. In addition, these developments could lead to ideal sources for ultrafast pump-probe experiments due to the perfect synchronization of the X-ray beam to the driver laser. (orig.)

  11. Analysis of sculptures using XRF and X-ray radiography

    Science.gov (United States)

    Calza, C.; Oliveira, D. F.; Freitas, R. P.; Rocha, H. S.; Nascimento, J. R.; Lopes, R. T.

    2015-11-01

    This work reports the analysis of two sacred images on polychrome wood using X-ray Radiography and Energy Dispersive X-Ray Fluorescence. The first case is the analysis of a sculpture portraying Saint Sebastian, the patron saint of Rio de Janeiro, which is considered the second most ancient sacred image of Brazil. This sculpture was made in Portugal and was transported to Brazil by Estácio Sá, founder of the city of Rio de Janeiro, in 1565. Nowadays, it is located on the main altar of the Church of Capuchin Friars. The second case is the analysis of a sculpture representing Our Lady of Conception, which is located in the D. João VI Museum (EBA/UFRJ, Rio de Janeiro). The objective of these analyses was to evaluate the general conditions of the sculptures, identifying possible problems and internal damages, areas that revealed signs of previous retouchings and the materials and pigments employed by the artists, in order to assist its restoration procedures. EDXRF measurements were carried out with a portable system, developed at the Nuclear Instrumentation Laboratory, consisting of a Si-PIN XR-100CR detector from Amptek and an Oxford TF3005 X-ray tube with W anode. An X-ray source, a CR System GE CR50P and IP detectors were used to perform the radiographs. The XRF analysis of the sculptures identified the original pigments in both cases and the radiographic images revealed details of the manufacture; restored regions; extensive use of lead white; presence of cracks on the wood; use of nails and spikes, etc.

  12. Energy-dispersive X-ray diffraction mapping on a benchtop X-ray fluorescence system

    OpenAIRE

    Lane, D W.; Nyombi, A.; Shackel, J.

    2014-01-01

    A method for energy-dispersive X-ray diffraction mapping is presented, using a conventional low-power benchtop X-ray fluorescence spectrometer, the Seiko Instruments SEA6000VX. Hyper spectral X-ray maps with a 10µm step size were collected from polished metal surfaces, sectioned Bi, Pb and steel shot gun pellets. Candidate diffraction lines were identified by eliminating those that matched a characteristic line for an element and those predicted for escape peaks, sum peaks, and Rayleigh and C...

  13. X-ray spectral properties of accretion discs in X-ray binaries

    Energy Technology Data Exchange (ETDEWEB)

    White, N.E.; Stella, L.; Parmar, A.N.

    1988-01-01

    Exosat observations are used to compare the spectral properties of the persistent emission from a number of X-ray burst sources, high-luminosity low-mass X-ray binaries (LMXRB) and galactic black hole candidates with various models for X-ray emission from an accretion disk surrounding a compact object in a binary system. It is shown that only a Comptonization model provides a good fit to all of the spectra considered. The fits to the spectra of the high-luminosity LMXRB systems necessitate an additional blackbody component with a luminosity 16 to 34 percent that from the Comptonized component. 82 references.

  14. Microfocussing of synchrotron X-rays using X-ray refractive lens developed at Indus-2 deep X-ray lithography beamline

    Indian Academy of Sciences (India)

    V P Dhamgaye; M K Tiwari; K J S Sawhney; G S Lodha

    2014-07-01

    X-ray lenses are fabricated in polymethyl methacrylate using deep X-ray lithography beamline of Indus-2. The focussing performance of these lenses is evaluated using Indus-2 and Diamond Light Source Ltd. The process steps for the fabrication of X-ray lenses and microfocussing at 10 keV at moderate and low emittance sources are compared.

  15. Principles of femtosecond X-ray/optical cross-correlation with X-ray induced transient optical reflectivity in solids

    OpenAIRE

    Eckert, S.; Beye, M.; Schlotter, W. F.; Dakovski, G. L.; Khalil, M.; Huse, N.; Föhlisch, A.; Pietzsch, A.; Quevedo, W.; Hantschmann, M.; Ochmann, M.; Ross, M.; Minitti, M. P.; Turner, J. J.; Moeller, S. P.

    2015-01-01

    The discovery of ultrafast X-ray induced optical reflectivity changes enabled the development of X-ray/optical cross correlation techniques at X-ray free electron lasers worldwide. We have now linked through experiment and theory the fundamental excitation and relaxation steps with the transient optical properties in finite solid samples. Therefore, we gain a thorough interpretation and an optimized detection scheme of X-ray induced changes to the refractive index and the X-ray/optical cross ...

  16. Neutron and X-ray Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Carini, Gabriella [SLAC National Accelerator Lab., Menlo Park, CA (United States); Denes, Peter [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Gruener, Sol [Cornell Univ., Ithaca, NY (United States); Lessner, Elianne [Dept. of Energy (DOE), Washington DC (United States). Office of Science Office of Basic Energy Sciences

    2012-08-01

    The Basic Energy Sciences (BES) X-ray and neutron user facilities attract more than 12,000 researchers each year to perform cutting-edge science at these state-of-the-art sources. While impressive breakthroughs in X-ray and neutron sources give us the powerful illumination needed to peer into the nano- to mesoscale world, a stumbling block continues to be the distinct lag in detector development, which is slowing progress toward data collection and analysis. Urgently needed detector improvements would reveal chemical composition and bonding in 3-D and in real time, allow researchers to watch “movies” of essential life processes as they happen, and make much more efficient use of every X-ray and neutron produced by the source The immense scientific potential that will come from better detectors has triggered worldwide activity in this area. Europe in particular has made impressive strides, outpacing the United States on several fronts. Maintaining a vital U.S. leadership in this key research endeavor will require targeted investments in detector R&D and infrastructure. To clarify the gap between detector development and source advances, and to identify opportunities to maximize the scientific impact of BES user facilities, a workshop on Neutron and X-ray Detectors was held August 1-3, 2012, in Gaithersburg, Maryland. Participants from universities, national laboratories, and commercial organizations from the United States and around the globe participated in plenary sessions, breakout groups, and joint open-discussion summary sessions. Sources have become immensely more powerful and are now brighter (more particles focused onto the sample per second) and more precise (higher spatial, spectral, and temporal resolution). To fully utilize these source advances, detectors must become faster, more efficient, and more discriminating. In supporting the mission of today’s cutting-edge neutron and X-ray sources, the workshop identified six detector research challenges

  17. Stopping x-ray pulses in a thin-film cavity via electromagnetically induced transparency

    CERN Document Server

    Kong, Xiangjin

    2015-01-01

    Stopping light via an electromagnetically induced transparency setup for x-ray pulses in a thin film planar x-ray cavity is investigated theoretically. The pulse is nearly resonant to the 14.4 keV M\\"ossbauer transition in $^{57}\\mathrm{Fe}$, with one nm-thin layer of the latter embedded in the thin-film x-ray cavity. Via a moderate hyperfine magnetic field which takes over the role of the control field, electromagnetically induced transparency and slowing down of the x-ray pulse occurs in the cavity setup. We show that by switching off the control magnetic field, a narrowband x-ray pulse can be completely stored in the cavity for approx. hundred ns. Coherent storage occurs in this scenario by imprinting the x-ray field onto nuclear coherences in a controllable and robust manner. Additional manipulation of the external magnetic field can lead to both group velocity and phase control of the pulse in the x-ray cavity sample.

  18. 3D Hydrodynamic & Radiative Transfer Models of X-ray Emission from Colliding Wind Binaries

    CERN Document Server

    Russell, Christopher M P; Owocki, Stanley P; Corcoran, Michael F; Hamaguchi, Kenji; Sugawara, Yasuharu

    2014-01-01

    Colliding wind binaries (CWBs) are unique laboratories for X-ray astrophysics. The massive stars in these systems possess powerful stellar winds with speeds up to $\\sim$3000 km s$^{-1}$, and their collision leads to hot plasma (up to $\\sim10^8$K) that emit thermal X-rays (up to $\\sim$10 keV). Many X-ray telescopes have observed CWBs, including Suzaku, and our work aims to model these X-ray observations. We use 3D smoothed particle hydrodynamics (SPH) to model the wind-wind interaction, and then perform 3D radiative transfer to compute the emergent X-ray flux, which is folded through X-ray telescopes' response functions to compare directly with observations. In these proceedings, we present our models of Suzaku observations of the multi-year-period, highly eccentric systems $\\eta$ Carinae and WR 140. The models reproduce the observations well away from periastron passage, but only $\\eta$ Carinae's X-ray spectrum is reproduced at periastron; the WR 140 model produces too much flux during this more complicated p...

  19. X-ray emission from protostellar jet HH 154: the first evidence of a diamond shock?

    CERN Document Server

    Bonito, R; Miceli, M; Peres, G; Micela, G; Favata, F

    2011-01-01

    X-ray emission from about ten protostellar jets has been discovered and it appears as a feature common to the most energetic jets. Although X-ray emission seems to originate from shocks internal to jets, the mechanism forming these shocks remains controversial. One of the best studied X-ray jet is HH 154 that has been observed by Chandra over a time base of about 10 years. We analyze the Chandra observations of HH 154 by investigating the evolution of its X-ray source. We show that the X-ray emission consists of a bright stationary component and a faint elongated component. We interpret the observations by developing a hydrodynamic model describing a protostellar jet originating from a nozzle and compare the X-ray emission synthesized from the model with the X-ray observations. The model takes into account the thermal conduction and radiative losses and shows that the jet/nozzle leads to the formation of a diamond shock at the nozzle exit. The shock is stationary over the period covered by our simulations and...

  20. Soft x-ray scattering using FEL radiation for probing near-solid density plasmas at few electronvolt temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Toleikis, S; Faustlin, R R; Cao, L; Doppner, T; Dusterer, S; Forster, E; Fortmann, C; Glenzer, S H; Gode, S; Gregori, G; Irsig, R; Laarmann, T; Lee, H J; Li, B; Meiwes-Broer, K; Przystawik, A; Radcliffe, P; Redmer, R; Tavella, F; Thiele, R; Tiggesbaumker, J; Truong, N X; Uschmann, I; Zastrau, U; Tschentscher, T

    2009-03-03

    We report on soft x-ray scattering experiments on cryogenic hydrogen and simple metal targets. As a source of intense and ultrashort soft x-ray pulses we have used free-electron laser radiation at 92 eV photon energy from FLASH at DESY, Hamburg. X-ray pulses with energies up to 100 {micro}J and durations below 50 fs provide interaction with the target leading simultaneously to plasma formation and scattering. Experiments exploiting both of these interactions have been carried out, using the same experimental setup. Firstly, recording of soft x-ray inelastic scattering from near-solid density hydrogen plasmas at few electronvolt temperatures confirms the feasibility of this diagnostics technique. Secondly, the soft x-ray excitation of few electronvolt solid-density plasmas in simple metals could be studied by recording soft x-ray line and continuum emission integrated over emission times from fs to ns.

  1. X-ray-induced radiophotodynamic therapy (RPDT) using lanthanide micelles: Beyond depth limitations

    Institute of Scientific and Technical Information of China (English)

    Slavka Kascakova[1,2; Alexandre Giuliani[1,3; Sara Lacerda[4; Agnes Pallier[4; Pascal Mercere[1; eva Toth[4; Matthieu Refregiers[1

    2015-01-01

    We report lanthanide-based micelles integrating hypericin (Hyp) for X-ray- triggered photodynamic therapy (PDT). The lanthanide luminescence induced by X-ray irradiation excites the photosensitizer, which leads to the generation of singlet oxygen. This versatile approach can be extended to other photosensitizers or other types of liponanoparticles and can allow for magnetic resonance imaging (MRI) guidance.

  2. Soft X-ray Absorbers Enabling Study of the Diffuse X-ray Background Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Absorbers for soft x-rays need to be made thinner and with larger area, to collect more photons, and with minimal number of support stems. However, the structure is...

  3. Calculation of x-ray scattering patterns from nanocrystals at high x-ray intensity

    CERN Document Server

    Abdullah, Malik Muhammad; Son, Sang-Kil; Santra, Robin

    2016-01-01

    We present a generalized method to describe the x-ray scattering intensity of the Bragg spots in a diffraction pattern from nanocrystals exposed to intense x-ray pulses. Our method involves the subdivision of a crystal into smaller units. In order to calculate the dynamics within every unit we employ a Monte-Carlo (MC)-molecular dynamics (MD)-ab-initio hybrid framework using real space periodic boundary conditions. By combining all the units we simulate the diffraction pattern of a crystal larger than the transverse x-ray beam profile, a situation commonly encountered in femtosecond nanocrystallography experiments with focused x-ray free-electron laser radiation. Radiation damage is not spatially uniform and depends on the fluence associated with each specific region inside the crystal. To investigate the effects of uniform and non-uniform fluence distribution we have used two different spatial beam profiles, gaussian and flattop.

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

    DEFF Research Database (Denmark)

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

    1992-01-01

    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......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...

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

    Energy Technology Data Exchange (ETDEWEB)

    Larson, B.C.

    1999-05-23

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

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

    CERN Document Server

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

    2016-01-01

    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 therefore a more superficial analysis. We show that the combination of both excitation sources can provide extremely valuable information about the structure of the artwork.

  7. Nanofocusing refractive X-ray lenses

    Energy Technology Data Exchange (ETDEWEB)

    Boye, Pit

    2010-02-05

    This thesis is concerned with the optimization and development of the production of nanofocusing refractive X-ray lenses. These optics made of either silicon or diamond are well-suited for high resolution X-ray microscopy. The goal of this work is the design of a reproducible manufacturing process which allows the production of silicon lenses with high precision, high quality and high piece number. Furthermore a process for the production of diamond lenses is to be developed and established. In this work, the theoretical basics of X-rays and their interaction with matter are described. Especially, aspects of synchrotron radiation are emphasized. Important in X-ray microscopy are the different optics. The details, advantages and disadvantages, in particular those of refractive lenses are given. To achieve small X-ray beams well beyond the 100 nm range a small focal length is required. This is achieved in refractive lenses by moving to a compact lens design where several single lenses are stacked behind each other. The, so-called nanofocusing refractive lenses (NFLs) have a parabolic cylindrical shape with lateral structure sizes in the micrometer range. NFLs are produced by using micro-machining techniques. These micro-fabrication processes and technologies are introduced. The results of the optimization and the final fabrication process for silicon lenses are presented. Subsequently, two experiments that are exemplary for the use of NFLs, are introduced. The rst one employs a high-resolution scanning fluorescence mapping of a geological sample, and the second one is a coherent x-ray diffraction imaging (CXDI) experiment. CXDI is able to reconstruct the illuminated object from recorded coherent diffraction patterns. In a scanning mode, referred to as ptychography, this method is even able to reconstruct the illumination and the object simultaneously. Especially the reconstructed illumination and the possibility of computed propagation of the wave field along the

  8. X-RAY POLARIZATION FROM HIGH-MASS X-RAY BINARIES

    Energy Technology Data Exchange (ETDEWEB)

    Kallman, T. [NASA/GSFC, Code 662, Greenbelt, MD 20771 (United States); Dorodnitsyn, A. [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Blondin, J. [Department of Physics, North Carolina State University, Raleigh, NC 27695-8202 (United States)

    2015-12-10

    X-ray astronomy allows study of objects that may be associated with compact objects, i.e., neutron stars or black holes, and also may contain strong magnetic fields. Such objects are categorically nonspherical, and likely noncircular when projected on the sky. Polarization allows study of such geometric effects, and X-ray polarimetry is likely to become feasible for a significant number of sources in the future. Potential targets for future X-ray polarization observations are the high-mass X-ray binaries (HMXBs), which consist of a compact object in orbit with an early-type star. In this paper we show that X-ray polarization from HMXBs has a distinct signature that depends on the source inclination and orbital phase. The presence of the X-ray source displaced from the star creates linear polarization even if the primary wind is spherically symmetric whenever the system is viewed away from conjunction. Direct X-rays dilute this polarization whenever the X-ray source is not eclipsed; at mid-eclipse the net polarization is expected to be small or zero if the wind is circularly symmetric around the line of centers. Resonance line scattering increases the scattering fraction, often by large factors, over the energy band spanned by resonance lines. Real winds are not expected to be spherically symmetric, or circularly symmetric around the line of centers, owing to the combined effects of the compact object gravity and ionization on the wind hydrodynamics. A sample calculation shows that this creates polarization fractions ranging up to tens of percent at mid-eclipse.

  9. The ITER core imaging x-ray spectrometer: x-ray calorimeter performance.

    Science.gov (United States)

    Beiersdorfer, P; Brown, G V; Clementson, J; Dunn, J; Morris, K; Wang, E; Kelley, R L; Kilbourne, C A; Porter, F S; Bitter, M; Feder, R; Hill, K W; Johnson, D; Barnsley, R

    2010-10-01

    We describe the anticipated performance of an x-ray microcalorimeter instrument on ITER. As part of the core imaging x-ray spectrometer, the instrument will augment the imaging crystal spectrometers by providing a survey of the concentration of heavy ion plasma impurities in the core and possibly ion temperature values from the emission lines of different elemental ions located at various radial positions.

  10. The X-ray Spectral Evolution of Galactic Black Hole X-ray Binaries Toward Quiescence

    CERN Document Server

    Plotkin, Richard M; Jonker, Peter G

    2013-01-01

    Most transient black hole X-ray binaries (BHXBs) spend the bulk of their time in a quiescent state, where they accrete matter from their companion star at highly sub-Eddington luminosities (we define quiescence here as a normalized Eddington ratio l_x = L_{0.5-10 keV}}/L_{Edd} < 1e-5). Here, we present Chandra X-ray imaging spectroscopy for three BHXB systems (H 1743-322, MAXI J1659-152, and XTE J1752-223) as they fade into quiescence following an outburst. Multiple X-ray observations were taken within one month of each other, allowing us to track each individual system's X-ray spectral evolution during its decay. We compare these three systems to other BHXB systems. We confirm that quiescent BHXBs have softer X-ray spectra than low-hard state BHXBs, and that quiescent BHXB spectral properties show no dependence on the binary system's orbital parameters. However, the observed anti-correlation between X-ray photon index and l_x in the low-hard state does not continue once a BHXB enters quiescence. Instead, ...

  11. Development of X-ray CCD camera based X-ray micro-CT system

    Science.gov (United States)

    Sarkar, Partha S.; Ray, N. K.; Pal, Manoj K.; Baribaddala, Ravi; Agrawal, Ashish; Kashyap, Y.; Sinha, A.; Gadkari, S. C.

    2017-02-01

    Availability of microfocus X-ray sources and high resolution X-ray area detectors has made it possible for high resolution microtomography studies to be performed outside the purview of synchrotron. In this paper, we present the work towards the use of an external shutter on a high resolution microtomography system using X-ray CCD camera as a detector. During micro computed tomography experiments, the X-ray source is continuously ON and owing to the readout mechanism of the CCD detector electronics, the detector registers photons reaching it during the read-out period too. This introduces a shadow like pattern in the image known as smear whose direction is defined by the vertical shift register. To resolve this issue, the developed system has been incorporated with a synchronized shutter just in front of the X-ray source. This is positioned in the X-ray beam path during the image readout period and out of the beam path during the image acquisition period. This technique has resulted in improved data quality and hence the same is reflected in the reconstructed images.

  12. Magnetar-like X-ray bursts from an anomalous X-ray pulsar.

    Science.gov (United States)

    Gavriil, F P; Kaspi, V M; Woods, P M

    2002-09-12

    Anomalous X-ray pulsars (AXPs) are a class of rare X-ray emitting pulsars whose energy source has been perplexing for some 20 years. Unlike other X-ray emitting pulsars, AXPs cannot be powered by rotational energy or by accretion of matter from a binary companion star, hence the designation 'anomalous'. Many of the rotational and radiative properties of the AXPs are strikingly similar to those of another class of exotic objects, the soft-gamma-ray repeaters (SGRs). But the defining property of the SGRs--their low-energy-gamma-ray and X-ray bursts--has not hitherto been observed for AXPs. Soft-gamma-ray repeaters are thought to be 'magnetars', which are young neutron stars whose emission is powered by the decay of an ultra-high magnetic field; the suggestion that AXPs might also be magnetars has been controversial. Here we report two X-ray bursts, with properties similar to those of SGRs, from the direction of the anomalous X-ray pulsar 1E1048.1 - 5937. These events imply a close relationship (perhaps evolutionary) between AXPs and SGRs, with both being magnetars.

  13. The Cambridge-Cambridge X-ray Serendipity Survey: I X-ray luminous galaxies

    Science.gov (United States)

    Boyle, B. J.; Mcmahon, R. G.; Wilkes, B. J.; Elvis, M.

    1994-01-01

    We report on the first results obtained from a new optical identification program of 123 faint X-ray sources with S(0.5-2 keV) greater than 2 x 10(exp -14) erg/s/sq cm serendipitously detected in ROSAT PSPC pointed observations. We have spectroscopically identified the optical counterparts to more than 100 sources in this survey. Although the majority of the sample (68 objects) are QSO's, we have also identified 12 narrow emission line galaxies which have extreme X-ray luminosities (10(exp 42) less than L(sub X) less than 10(exp 43.5) erg/s). Subsequent spectroscopy reveals them to be a mixture of star-burst galaxies and Seyfert 2 galaxies in approximately equal numbers. Combined with potentially similar objects identified in the Einstein Extended Medium Sensitivity Survey, these X-ray luminous galaxies exhibit a rate of cosmological evolution, L(sub X) varies as (1 + z)(exp 2.5 +/- 1.0), consistent with that derived for X-ray QSO's. This evolution, coupled with the steep slope determined for the faint end of the X-ray luminosity function (Phi(L(sub X)) varies as L(sub X)(exp -1.9)), implies that such objects could comprise 15-35% of the soft (1-2 keV) X-ray background.

  14. A Transmissive X-ray Polarimeter Design For Hard X-ray Focusing Telescopes

    CERN Document Server

    Li, Hong; Ji, Jianfeng; Deng, Zhi; He, Li; Zeng, Ming; Li, Tenglin; Liu, Yinong; Heng, Peiyin; Wu, Qiong; Han, Dong; Dong, Yongwei; Lu, Fangjun; Zhang, Shuangnan

    2015-01-01

    The X-ray Timing and Polarization (XTP) is a mission concept for a future space borne X-ray observatory and is currently selected for early phase study. We present a new design of X-ray polarimeter based on the time projection gas chamber. The polarimeter, placed above the focal plane, has an additional rear window that allows hard X-rays to penetrate (a transmission of nearly 80% at 6 keV) through it and reach the detector on the focal plane. Such a design is to compensate the low detection efficiency of gas detectors, at a low cost of sensitivity, and can maximize the science return of multilayer hard X-ray telescopes without the risk of moving focal plane instruments. The sensitivity in terms of minimum detectable polarization, based on current instrument configuration, is expected to be 3% for a 1mCrab source given an observing time of 10^5 s. We present preliminary test results, including photoelectron tracks and modulation curves, using a test chamber and polarized X-ray sources in the lab.

  15. Development of X-ray CCD camera based X-ray micro-CT system.

    Science.gov (United States)

    Sarkar, Partha S; Ray, N K; Pal, Manoj K; Baribaddala, Ravi; Agrawal, Ashish; Kashyap, Y; Sinha, A; Gadkari, S C

    2017-02-01

    Availability of microfocus X-ray sources and high resolution X-ray area detectors has made it possible for high resolution microtomography studies to be performed outside the purview of synchrotron. In this paper, we present the work towards the use of an external shutter on a high resolution microtomography system using X-ray CCD camera as a detector. During micro computed tomography experiments, the X-ray source is continuously ON and owing to the readout mechanism of the CCD detector electronics, the detector registers photons reaching it during the read-out period too. This introduces a shadow like pattern in the image known as smear whose direction is defined by the vertical shift register. To resolve this issue, the developed system has been incorporated with a synchronized shutter just in front of the X-ray source. This is positioned in the X-ray beam path during the image readout period and out of the beam path during the image acquisition period. This technique has resulted in improved data quality and hence the same is reflected in the reconstructed images.

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

    CERN Document Server

    Warwick, R S

    2014-01-01

    Using the XMM-Newton Slew Survey, we construct a hard-band selected sample of low-luminosity Galactic X-ray sources. Two source populations are represented, namely coronally-active stars and binaries (ASBs) and cataclysmic variables (CVs), with X-ray luminosities collectively spanning the range 10^(28-34) erg/s (2-10 keV). We derive the 2-10 keV X-ray luminosity function (XLF) and volume emissivity of each population. Scaled to the local stellar mass density, the latter is found to be 1.08 +/- 0.16 x 10^28 erg/s/M and 2.5 +/- 0.6 x 10^27 erg/s/M, for the ASBs and CVs respectively, which in total is a factor 2 higher than previous estimates. We employ the new XLFs to predict the X-ray source counts on the Galactic plane at l = 28.5 deg and show that the result is consistent with current observational constraints. The X-ray emission of faint, unresolved ASBs and CVs can account for a substantial fraction of the Galactic ridge X-ray emission (GRXE). We discuss a model in which roughly 80 per cent of the 6-10 keV...

  17. HERMES: a soft X-ray beamline dedicated to X-ray microscopy.

    Science.gov (United States)

    Belkhou, Rachid; Stanescu, Stefan; Swaraj, Sufal; Besson, Adrien; Ledoux, Milena; Hajlaoui, Mahdi; Dalle, Didier

    2015-07-01

    The HERMES beamline (High Efficiency and Resolution beamline dedicated to X-ray Microscopy and Electron Spectroscopy), built at Synchrotron SOLEIL (Saint-Auban, France), is dedicated to soft X-ray microscopy. The beamline combines two complementary microscopy methods: XPEEM (X-ray Photo Emitted Electron Microscopy) and STXM (Scanning Transmission X-ray Microscopy) with an aim to reach spatial resolution below 20 nm and to fully exploit the local spectroscopic capabilities of the two microscopes. The availability of the two methods within the same beamline enables the users to select the appropriate approach to study their specific case in terms of sample environment, spectroscopy methods, probing depth etc. In this paper a general description of the beamline and its design are presented. The performance and specifications of the beamline will be reviewed in detail. Moreover, the article is aiming to demonstrate how the beamline performances have been specifically optimized to fulfill the specific requirements of a soft X-ray microscopy beamline in terms of flux, resolution, beam size etc. Special attention has been dedicated to overcome some limiting and hindering problems that are usually encountered on soft X-ray beamlines such as carbon contamination, thermal stability and spectral purity.

  18. X-ray luminosity functions of different morphological and X-ray type AGN populations

    CERN Document Server

    Pović, M; Sánchez-Portal, M; Bongiovanni, A; Cepa, J; Lorenzo, M Fernández; Lara-López, M A; Gallego, J; Ederoclite, A; Márquez, I; Masegosa, J; Alfaro, E; Castañeda, H; González-Serrano, J I; González, J J; 10.1002/asna.201211840

    2013-01-01

    Luminosity functions are one of the most important observational clues when studying galaxy evolution over cosmic time. In this paper we present the X-ray luminosity functions of X-ray detected AGN in the SXDS and GWS fields. The limiting fluxes of our samples are 9.0x10^(-15) and 4.8x10^(-16) erg/cm^2/sec^(-1) in the 0.5 - 7.0 keV band in the two fields, respectively. We carried out analysis in three X-ray bands and in two redshift intervals up to z < 1.4. Moreover, we derive the luminosity functions for different optical morphologies and X-ray types. We confirm strong luminosity evolution in all three bands, finding the most luminous objects at higher redshift. However, no signs of density evolution are found in any tested X-ray band. We obtain similar results for compact and early-type objects. Finally, we observe the `Steffen effect', where X-ray type-1 sources are more numerous at higher luminosities in comparison with type-2 sources.

  19. Evaluation of airborne lead levels in storage battery workshops and some welding environments in Kumasi metropolis in Ghana.

    Science.gov (United States)

    Dartey, E; Adimado, A A; Agyarko, K

    2010-05-01

    Airborne lead levels were assessed in nine workshops, three each from battery, electronic repair, and welding sources within the Kumasi Metropolis in Ghana. Samples were collected at 0, 2.5, and 5.0 m away from the emission source at the workshops during working hours and another at 5.0 m during break hours. Airborne lead particulates were collected and analyzed using the filter membrane technique and flame atomic absorption spectrophotometry, respectively. There were significant differences (p < or = 0.05) among the air lead levels from the workshops. Workshop 3b produced the highest significant values of air lead concentrations of 2,820.31 +/- 53.89, 2,406.74 +/- 71.87, 754.55 +/- 72.52, and 549.01 +/- 67.30 microg/m(3) at distances of 0, 2.5, 5.0, and 5.0 m (break-time measurement), respectively, while workshop 1w significantly produced the lowest air lead concentration values of 261.06 +/- 21.60, 190.92 +/- 36.90, 86.43 +/- 16.26, and 61.05 +/- 3.88 microg/m(3) at distances of 0, 2.5, 5.0, and 5.0 m (break-time measurement), respectively. The air lead levels reduced with distance from emission source at the workshops. At all the distances of measurement at working hours, the airborne lead levels were higher than the World Health Organization standard of 50 microg/m(3) and exceeded the threshold limit values of 100 to 150 microg/m(3) recommended in most jurisdictions. Workers and people in the immediate environs were exposed to air lead levels that were too high by most international standards, thus posing a serious threat to their health.

  20. A Test Facility For Astronomical X-Ray Optics

    DEFF Research Database (Denmark)

    Lewis, R. A.; Bordas, J.; Christensen, Finn Erland

    1989-01-01

    Grazing incidence x-ray optics for x-ray astronomical applications are used outside the earths atmosphere. These devices require a large collection aperture and the imaging of an x-ray source which is essentially placed at infinity. The ideal testing system for these optical elements has to appro......Grazing incidence x-ray optics for x-ray astronomical applications are used outside the earths atmosphere. These devices require a large collection aperture and the imaging of an x-ray source which is essentially placed at infinity. The ideal testing system for these optical elements has...

  1. Test facility for astronomical x-ray optics

    DEFF Research Database (Denmark)

    Christensen, Finn Erland; Lewis, Robert A.; Bordas, J.

    1990-01-01

    Grazing incidence x-ray optics for x-ray astronomical applications are used outside the earth's atmosphere. These devices require a large collection aperture and the imaging of an x-ray source that is essentially placed at infinity. The ideal testing system for these optical elements has to appro......Grazing incidence x-ray optics for x-ray astronomical applications are used outside the earth's atmosphere. These devices require a large collection aperture and the imaging of an x-ray source that is essentially placed at infinity. The ideal testing system for these optical elements has...

  2. X-ray bursts observed with JEM-X

    DEFF Research Database (Denmark)

    Brandt, Søren Kristian; Chenevez, Jérôme; Lund, Niels;

    2006-01-01

    We report on the search for X-ray bursts in the JEM-X X-ray monitor on INTEGRAL during the first two years of operations. More than 350 bursts from 25 different type-I X-ray burst sources were found.......We report on the search for X-ray bursts in the JEM-X X-ray monitor on INTEGRAL during the first two years of operations. More than 350 bursts from 25 different type-I X-ray burst sources were found....

  3. Material analysis with X-ray microdiffraction

    Energy Technology Data Exchange (ETDEWEB)

    Friedel, F.; Winkler, U.; Holtz, B. [ThyssenKrupp Stahl AG, Duisburg (Germany); Seyrich, R.; Ullrich, H.J. [Dresden University of Technology (Germany)

    2005-01-01

    Steel has continued to develop its status as a lightweight construction material for the design of vehicle bodies, most recently with the development of multi-phase steel. With a specific mixture of different phases in the steel microstructure, multi-phase steel combines high stability with good forming capacity. The characterisation of the complex structure of the multi-phase steel represents a challenge for metallurgists. For some years a new generation of X-ray diffractometers with two-dimensional (area) detectors and apparatus for local dissolved measurements are available to customers. This paper reports the applications and advantages of the modern X-ray diffractometry method. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  4. X-ray focusing using microchannel plates

    Science.gov (United States)

    Kaaret, P.; Geissbuehler, P.; Chen, A.; Glavinas, E.

    1992-01-01

    We present measurements of the X-ray focusing properties of square-pore microchannel plates (MCP's). Square-pore MCP's contain large numbers of closely packed optical surfaces, as required for grazing incidence X-ray optics. The surface of individual MCP channels has been measured and found to have high microroughness transverse to the channel axis and low microroughness parallel to the axis. The high frequency transverse roughness, on length scales greater than 400 nm, has a rms value of 5.9 nm and a Gaussian autocorrelation function with correlation length of 1.41 micron. We find that the geometric misalignments of the surfaces of different channels limit the angular resolution obtainable with current samples of MCP's to 7.1 arcmin.

  5. Beyond Chandra - the X-ray Surveyor

    CERN Document Server

    Weisskopf, Martin C; Tananbaum, Harvey; Vikhlinin, Alexey

    2015-01-01

    Over the past 16 years, NASA's Chandra X-ray Observatory has provided an unparalleled means for exploring the universe with its half-arcsecond angular resolution. Chandra studies have deepened our understanding of galaxy clusters, active galactic nuclei, galaxies, supernova remnants, planets, and solar system objects addressing almost all areas of current interest in astronomy and astrophysics. As we look beyond Chandra, it is clear that comparable or even better angular resolution with greatly increased photon throughput is essential to address even more demanding science questions, such as the formation and subsequent growth of black hole seeds at very high redshift; the emergence of the first galaxy groups; and details of feedback over a large range of scales from galaxies to galaxy clusters. Recently, NASA Marshall Space Flight Center, together with the Smithsonian Astrophysical Observatory, has initiated a concept study for such a mission named the X-ray Surveyor. This study starts with a baseline payloa...

  6. Tomographic x-ray absorption spectroscopy.

    Energy Technology Data Exchange (ETDEWEB)

    Schroer, C. G.; Kuhlmann, M.; Gunzler, T. F.; Lengeler, B.; Richwin, M.; Griesebock, B.; Lutzenkirchen-Hecht, D.; Frahm, R.; Ziegler, E.; Mashayekhi, A.; Haeffner, D. R.; Grunwaldt, J. -D.; Baiker, A.; Experimental Facilities Division (APS); Aachen Univ.; HASYLAB at DESY; Bergische Univ. Wuppertal; ESRF; Inst. for Chemical and Bioengineering

    2004-01-01

    Hard x-ray absorption spectroscopy is combined with scanning microtomography to reconstruct full near edge spectra of an elemental species at each point on an arbitrary virtual section through a sample. These spectra reveal the local concentration of different chemical compounds of the absorbing element inside the sample and give insight into the oxidation state and the local projected free density of states. The method is implemented by combining a quick scanning monochromator and data acquisition system with a scanning microprobe setup based on refractive x-ray lenses. The full XANES spectra reconstructed at each point of the tomographic slice allow one to detect slight variations in concentration of the chemical compounds, such as Cu and Cu(I){sub 2}O.

  7. X-Ray Polarimetry with GEMS

    Science.gov (United States)

    Strohmayer, Tod

    2011-01-01

    The polarization properties of cosmic X-ray sources are still largely unexplored. The Gravity and Extreme Magnetism SMEX (GEMS) will carry out the first sensitive X-ray polarization survey of a wide range of sources including; accreting compact objects (black holes and neutron stars), AGN, supernova remnants, magnetars and rotation-powered pulsars. GEMS employs grazing-incidence foil mirrors and novel time-projection chamber (TPC) polarimeters leveraging the photoelectric effect to achieve high polarization sensitivity in the 2 - 10 keV band. I will provide an update of the project status, illustrate the expected performance with several science examples, and provide a brief overview of the data analysis challenges

  8. Burst Detector X-Ray IIR

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-02-01

    The Burst Detector X-Ray (BDX) instrument for the Block IIR series of Global Positioning System satellites is described. The BDX instrument can locate and characterize exoatmospheric nuclear detonations by using four sensors consisting of sets of filters over silicon diodes to detect x rays of various energies from the burst. On the BDX-IIR, a fifth sensor with a response spanning those of the other sensors confirms coincidences among the four main channels. The mechanical and electronic features of the BDX-IIR and its sensors are described. The calibrations and the system tests used in flight are presented. The commands for the BDX-IIR are given. The messages sent from the BDX-IIR are described in detail.

  9. How x rays inhibit amphibian limb regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Maden, M.; Wallace, H.

    1976-07-01

    The effects of an inhibiting dose of 2,000 rad of x-rays on the regenerating limbs of axolotl larvae have been examined in a histological and cytological study. Particular attention was paid to the mitotic indices of normal and irradiated epidermal and blastemal cells. Both the characteristic pattern of epidermal mitotic stimulation which normally follows amputation and the later increase in blastemal mitoses are suppressed by irradiation. In most cells the effects are permanent, but in a small proportion a mitotic delay is induced and upon subsequent division chromosome damage in the form of micronuclei is revealed. Thus irradiated cells which do divide almost certainly die. These results are discussed in relation to other theories of x-ray inhibition of regeneration with particular reference to the view that irradiated cells can be reactivated.

  10. X-ray detection using magnetic calorimeters

    Energy Technology Data Exchange (ETDEWEB)

    Schoenefeld, J. E-mail: e62@urz.uni-heidelberg.de; Enss, C.; Fleischmann, A.; Sollner, J.; Horst, K.; Adams, J.S.; Kim, Y.H.; Seidel, G.M.; Bandler, S.R

    2000-04-07

    Using a magnetic calorimeter, we have obtained an energy resolution of 13 eV in the detection of 6 keV X-rays. The calorimeter consisted of a 50 {mu}m diameter, 25 {mu}m thick Au sensor doped with 300 ppm Er. A 100x100 {mu}m square, 8 {mu}m thick Au absorber was attached to the sensor. At the operating temperature of 33 mK and with a field of 3 mT, the calorimeter had a heat capacity of 1.3x10{sup -12} J/K. With a magnetic calorimeter optimized for X-ray detection an order of magnitude improvement in resolution should be possible.

  11. XRASE: The X-Ray Spectroscopic Explorer

    DEFF Research Database (Denmark)

    Schnopper, H.W.; Silver, E.; Murray, S.

    2001-01-01

    The X-Ray Spectroscopic Explorer (XRASE) has a unique combination of features that will make it possible to address many of NASA's scientific goals. These include how galaxy clusters form, the physics and chemistry of the ISM, the heating of stellar coronae, the amount and content of intergalactic...... baryonic matter, the mass of black holes and the formation of disks and jets in AGN and galactic binaries. XRASE has a thin foil, multilayered telescope with a large collecting area up to 10 keV, especially in the Fe K alpha region (1100 cm(2)). Its microcalorimeter array combines high energy resolution (7...... eV at 6 keV) and efficiency with a field-of-view of 26 arcmin(2) . A deep orbit allows for long, continuous observations. Monitoring instruments in the optical (WOM-X), UV (TAUVEX) and hard X-RAY (GRAM) bands will offer exceptional opportunities to make simultaneous multi-wavelength observations....

  12. Soft X-ray Polarimetry Development

    Science.gov (United States)

    Marshall, Herman; Schulz, Norbert S.; Heine, Sarah

    2016-07-01

    We present continued development of a telescope for measuring linear X-ray polarization over the 0.2-0.8 keV band. We employ multilayer-coated mirrors as Bragg reflectors at the Brewster angle. By matching to the dispersion of a spectrometer, one may take advantage of high multilayer reflectivities and achieve polarization modulation factors over 95%. We have constructed a source of polarized X-rays that operates at a wide range of energies with a selectable polarization angle. We will present results from measurements of new laterally graded multilayer mirrors and new gratings essential to the design. Finally, we will present a design for a small telescope for suborbital or orbital missions. A suborbital mission could measure the polarization of a blazar such as Mk 421 to 5-10 percent while an orbital version could measure the polarizations of neutron stars, active galactic nuclei, and blazars.

  13. Modeling X-ray Emission Around Galaxies

    CERN Document Server

    Anderson, Michael E

    2014-01-01

    Extended X-ray emission can be studied either spatially (through its surface brightness profile) or spectrally (by analyzing the spectrum at various locations in the field). Both techniques have advantages and disadvantages, and when the emission becomes particularly faint and/or extended, the two methods can disagree. We argue that an ideal approach would be to model the events file directly, and therefore to use both the spectral and spatial information which are simultaneously available for each event. In this work we propose a first step in this direction, introducing a method for spatial analysis which can be extended to leverage spectral information simultaneously. We construct a model for the entire X-ray image in a given energy band, and generate a likelihood function to compare the model to the data. A critical goal of this modeling is disentangling vignetted and unvignetted backgrounds through their different spatial distributions. Employing either maximum likelihood or Markov Chain Monte Carlo, we ...

  14. X-ray Compton line scan tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kupsch, Andreas; Lange, Axel; Jaenisch, Gerd-Ruediger [Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin (Germany). Fachgruppe 8.5 - Mikro-ZfP; Hentschel, Manfred P. [Technische Univ. Berlin (Germany); Kardjilov, Nikolay; Markoetter, Henning; Hilger, Andre; Manke, Ingo [Helmholtz-Zentrum Berlin (HZB) (Germany); Toetzke, Christian [Potsdam Univ. (Germany)

    2015-07-01

    The potentials of incoherent X-ray scattering (Compton) computed tomography (CT) are investigated. The imaging of materials of very different atomic number or density at once is generally a perpetual challenge for X-ray tomography or radiography. In a basic laboratory set-up for simultaneous perpendicular Compton scattering and direct beam attenuation tomography are conducted by single channel photon counting line scans. This results in asymmetric distortions of the projection profiles of the scattering CT data set. In a first approach, corrections of Compton scattering data by taking advantage of rotational symmetry yield tomograms without major geometric artefacts. A cylindrical sample composed of PE, PA, PVC, glass and wood demonstrates similar Compton contrast for all the substances, while the conventional absorption tomogram only reveals the two high order materials. Comparison to neutron tomography reveals astonishing similarities except for the glass component (without hydrogen). Therefore, Compton CT offers the potential to replace neutron tomography, which requires much more efforts.

  15. Large thin adaptive x-ray mirrors

    Science.gov (United States)

    Doel, Peter; Atkins, Carolyn; Thompson, Samantha; Brooks, David; Yao, Jun; Feldman, Charlotte; Willingale, Richard; Button, Tim; Zhang, Dou; James, Ady

    2007-09-01

    This paper describes the progress made in a proof of concept study and recent results of a research program into large active x-ray mirrors that is part of the UK Smart X-ray Optics project. The ultimate aim is to apply the techniques of active/adaptive optics to the next generation of nested shell astronomical X-ray space telescopes. A variety of deformable mirror technologies are currently available, the most promising of which for active X-ray mirrors are probably unimorph and bimorph piezoelectric mirrors. In this type of mirror one or more sheets of piezoelectric material are bonded to or coated with a passive reflective layer. On the back or between the piezoceramic layer/layers are series of electrodes. Application of an electric field causes the piezoelectric material to undergo local deformation thus changing the mirror shape. Starting in 2005 a proof of concept active mirror research program has been undertaken. This work included modelling and development of actively controlled thin shell mirrors. Finite element models of piezo-electric actuated mirrors have been developed and verified against experimental test systems. This has included the modelling and test of piezo-electric hexagonal unimorph segments. Various actuator types and low shrinkage conductive bonding methods have been investigated and laboratory tests of the use of piezo-electric actuators to adjust the form of an XMM-Newton space telescope engineering model mirror shell have been conducted and show that movement of the optics at the required level is achievable. Promising technological approaches have been identified including moulded piezo-ceramics and piezo-electrics fibre bundles.

  16. Sample holder for X-ray diffractometry

    Science.gov (United States)

    Hesch, Victor L.

    1992-01-01

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

  17. Early x-ray diagnosis of coxarthrosis

    Energy Technology Data Exchange (ETDEWEB)

    Lingg, G.; Nebel, G.

    Radiological and pathological comparisons on specimen of femur head and neck at autopsy have shown a statistical relationship between osteophytosis of the femoral head and ulcerations of the joint cartilage. Especially, there are highly significant relationships between the length of osteophytes and the diameter of the ulcera. The 'plaque'-sign is shown to be a very sensitive indicator of early arthrosis. So there exist semiquantitative parameters for the X-ray diagnosis of early coxarthrosis.

  18. [X-ray diffraction spectrum of heroin].

    Science.gov (United States)

    Hu, X; Kan, J; Yuan, B

    1999-06-01

    In this paper, practical measured X-ray diffraction spectra of heroin and opium are given and the parameters of each diffraction peak of the heroin are listed. The heroin belongs to orthorhombic crystal system; the basic vectors of the primitive cell are: a = 8.003, b = 14.373, c = 16.092 x 10(-10) m. As compared with the standard spectra of pure heroin and sucrose, the main doped additive checked by us, is sugar affirmatively.

  19. X-ray Studies of Flaring Plasma

    Indian Academy of Sciences (India)

    B. Sylwester; J. Sylwester; K. J. H. Phillips

    2008-03-01

    We present some methods of X-ray data analysis employed in our laboratory for deducing the physical parameters of flaring plasma. For example, we have used a flare well observed with Polish instrument RESIK aboard Russian CORONAS-F satellite. Based on a careful instrument calibration, the absolute fluxes in a number of individual spectral lines have been obtained. The analysis of these lines allows us to follow the evolution of important thermodynamic parameters characterizing the emitting plasma throughout this flare evolution.

  20. Surface-Enhanced X-Ray Fluorescence

    Science.gov (United States)

    Anderson, Mark

    2010-01-01

    Surface-enhanced x-ray fluorescence (SEn-XRF) spectroscopy is a form of surface- enhanced spectroscopy that was conceived as a means of obtaining greater sensitivity in x-ray fluorescence (XRF) spectroscopy. As such, SEn-XRF spectroscopy joins the ranks of such other, longer-wavelength surface-enhanced spectroscopies as those based on surface-enhanced Raman scattering (SERS), surface-enhanced resonance Raman scattering (SERRS), and surfaceenhanced infrared Raman absorption (SEIRA), which have been described in previous NASA Tech Briefs articles. XRF spectroscopy has been used in analytical chemistry for determining the elemental compositions of small samples. XRF spectroscopy is rapid and quantitative and has been applied to a variety of metal and mineralogical samples. The main drawback of XRF spectroscopy as practiced heretofore is that sensitivity has not been as high as required for some applications. In SEn-XRF as in the other surface-enhanced spectroscopies, one exploits several interacting near-field phenomena, occurring on nanotextured surfaces, that give rise to local concentrations of incident far-field illumination. In this case, the far-field illumination comes from an x-ray source. Depending on the chemical composition and the geometry of a given nanotextured surface, these phenomena could include the lightning-rod effect (concentration of electric fields at the sharpest points on needlelike surface features), surface plasmon resonances, and grazing incidence geometric effects. In the far field, the observable effect of these phenomena is an increase in the intensity of the spectrum of interest - in this case, the x-ray fluorescence spectrum of chemical elements of interest that may be present within a surface layer at distances no more than a few nanometers from the surface.

  1. POST TRAUMATIC KNEE FRACTURE ( X-RAY

    Directory of Open Access Journals (Sweden)

    Dr. Jalaja Prakash.

    2013-06-01

    Full Text Available A 51 year old male patient met with a road traffic accident on August 2010. On examination thepatient was unable to stand and walk. His right knee was swollen and complained of pain withinstability. The X-Ray of patient showed transverse fracture of patella along with comminutedfracture of lower end of femur. He was treated with “K” wire and internal fixation. The patient wasadvised early physiotherapy which include range of motion exercises, knee strengthening and gaittraining.

  2. Basic of X-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Giacovazzo, C. [Bari Univ. (Italy). Dip. Geomineralogico

    1996-09-01

    The basic concepts of X-ray diffraction may be more easily understood if it is made preliminary use of a mathematical background. In these pages the authors will first define the delta function and its use for the representation of a lattice. Then the concepts of Fourier transform and convolution are given. At the end of this talk one should realize that a crystal is the convolution of the lattice with a function representing the content of the unit cell.

  3. Compton polarimeter as a focal plane detector for hard X-ray telescope: sensitivity estimation with Geant4 simulations

    Science.gov (United States)

    Chattopadhyay, T.; Vadawale, S. V.; Pendharkar, J.

    2013-04-01

    X-ray polarimetry can be an important tool for investigating various physical processes as well as their geometries at the celestial X-ray sources. However, X-ray polarimetry has not progressed much compared to the spectroscopy, timing and imaging mainly due to the extremely photon-hungry nature of X-ray polarimetry leading to severely limited sensitivity of X-ray polarimeters. The great improvement in sensitivity in spectroscopy and imaging was possible due to focusing X-ray optics which is effective only at the soft X-ray energy range. Similar improvement in sensitivity of polarisation measurement at soft X-ray range is expected in near future with the advent of GEM based photoelectric polarimeters. However, at energies >10 keV, even spectroscopic and imaging sensitivities of X-ray detector are limited due to lack of focusing optics. Thus hard X-ray polarimetry so far has been largely unexplored area. On the other hand, typically the polarisation degree is expected to increase at higher energies as the radiation from non-thermal processes is dominant fraction. So polarisation measurement in hard X-ray can yield significant insights into such processes. With the recent availability of hard X-ray optics (e.g. with upcoming NuSTAR, Astro-H missions) which can focus X-rays from 5 KeV to 80 KeV, sensitivity of X-ray detectors in hard X-ray range is expected to improve significantly. In this context we explore feasibility of a focal plane hard X-ray polarimeter based on Compton scattering having a thin plastic scatterer surrounded by cylindrical array scintillator detectors. We have carried out detailed Geant4 simulation to estimate the modulation factor for 100 % polarized beam as well as polarimetric efficiency of this configuration. We have also validated these results with a semi-analytical approach. Here we present the initial results of polarisation sensitivities of such focal plane Compton polarimeter coupled with the reflection efficiency of present era hard X-ray

  4. The X-ray Telescope of CAST

    CERN Document Server

    Kuster, M; Cebrián, S; Davenport, M; Elefteriadis, C; Englhauser, J; Fischer, H; Franz, J; Friedrich, P; Hartmann, R; Heinsius, F H; Hoffmann, Dieter H H; Hoffmeister, G; Joux, J N; Königsmann, K C; Kang, D; Kotthaus, R; Lasseur, C; Lippitsch, A; Lutz, G; Morales, J; Papaevangelou, T; Rodríguez, A; Strüder, L; Vogel, J; Zioutas, K

    2007-01-01

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

  5. The x-ray telescope of CAST

    Science.gov (United States)

    Kuster, M.; Bräuninger, H.; Cebrián, S.; Davenport, M.; Eleftheriadis, C.; Englhauser, J.; Fischer, H.; Franz, J.; Friedrich, P.; Hartmann, R.; Heinsius, F. H.; Hoffmann, D. H. H.; Hoffmeister, G.; Joux, J. N.; Kang, D.; Königsmann, K.; Kotthaus, R.; Papaevangelou, T.; Lasseur, C.; Lippitsch, A.; Lutz, G.; Morales, J.; Rodríguez, A.; Strüder, L.; Vogel, J.; Zioutas

    2007-06-01

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

  6. Hard X-ray Timing with EXIST

    CERN Document Server

    Grindlay, J E

    2004-01-01

    The Energetic X-ray Timing Survey Telescope (EXIST) mission concept is under study as the Black Hole Finder Probe (BHFP), one of the three Einstein Probe missions in the Beyond Einstein Program in the current NASA Strategic Plan. EXIST would conduct an all-sky imaging hard X-ray ($\\sim$10-600 keV) survey with unprecedented sensitivity: about 5 $\\times 10^{-13}$ cgs over any factor of 2 bandwidth, or comparable to that achieved at soft X-rays in the ROSAT survey. The proposed angular resolution of 5arcmin, temporal resolution of 10microsec, energy resolution of 1-4 keV over the broad band, and duty cycle of 0.2-0.5 for continuous coverage of any source provide an unprecedented phase space for timing and spectral studies of black holes --from stellar to supermassive, as well as neutron stars and accreting white dwarfs. The large sky coverage allows intrinsically rare events to be studied. One particularly exciting example is the possible detection of tidal disruption of stars near quiescent AGN. Super flares fr...

  7. X-Ray parameters of lumbar spine

    Directory of Open Access Journals (Sweden)

    Otabek Ablyazov

    2012-05-01

    Full Text Available Knowledge of anatomic spinal structures, especially its relation-ship to the functions performed, is necessary to form a correct diagnosis. The anatomical structure of the vertebrae varies de-pending on the level of the spinal segment. Normal anatomical parameters, derived from bone structures of the spine, are roughly determined by X-ray method.This paper presents the results of the survey radiography of the lumbar spine in a straight line and lateral projections in 30 individ-uals without pathology spine, aged 21-60 years with frequently observed lumbar spinal stenosis stenosis. Applying X-ray method there were studied shape, height, and the contours of the vertebral bodies and intervertebral disc in the front (interpedicular and sagittal planes; there were measured dimensions of the lumbar canal and foramen holes in the same planes. Using X-ray method can fully identify the bone parameters of vertebral column. How-ever, the informativity of the method depends on knowledge of radiologist about topographic anatomical features of spine.

  8. The CAST X-ray telescope

    Energy Technology Data Exchange (ETDEWEB)

    Rosu, Madalin M. [Institut fuer Kernphysik, Technische Universitaet Darmstadt (Germany)

    2010-07-01

    CAST (CERN Axion Solar Telescope) is a project at the European Organization for Nuclear Research CERN in Geneva, which searches for Axions coming from the Sun. The most sensitive detector system used at CAST is the X-ray Wolter type I telescope. Its two constituents, the X-ray mirror optics and the fully depleted EPIC pn-CCD detector, were originally built for ABRIXAS and XMM-Newton space missions. Their combined use provides the X-ray telescope with the highest axion discovery potential of all CAST detectors, excellent imaging capability and almost 100% data tacking reliability in conditions of low background which is suppressed by a factor of 155 by focusing the photons from the aperture of the magnet of 14.5 cm{sup 2} to a spot of roughly 9.3 mm{sup 2} on the CCD chip. For achieving a high sensitivity the CCD chip is operated at -130 C in a vacuum vessel made of aluminum and a passive shield of copper and led to reduce the external {gamma}-ray. All these combined with a extremely thin and homogeneous entrance window of 20 nm located on the back side of the chip result in a quantum efficiency of >95% in the photon energy range of 1 to 7 keV, which is the interesting region for the axion search with the CAST experiment.

  9. AGN variability at hard X-rays

    CERN Document Server

    Soldi, S; Beckmann, V; Lubinski, P

    2010-01-01

    We present preliminary results on the variability properties of AGN above 20 keV in order to show the potential of the INTEGRAL IBIS/ISGRI and Swift/BAT instruments for hard X-ray timing analysis of AGN. The 15-50 keV light curves of 36 AGN observed by BAT during 5 years show significantly larger variations when the blazar population is considered (average normalized excess variance = 0.25) with respect to the Seyfert one (average normalized excess variance = 0.09). The hard X-ray luminosity is found to be anti-correlated to the variability amplitude in Seyfert galaxies and correlated to the black hole mass, confirming previous findings obtained with different AGN hard X-ray samples. We also present results on the Seyfert 1 galaxy IC 4329A, as an example of spectral variability study with INTEGRAL/ISGRI data. The position of the high-energy cut-off of this source is found to have varied during the INTEGRAL observations, pointing to a change of temperature of the Comptonising medium. For several bright Seyfert...

  10. Theoretical spectra of nonmagnetized low-mass X-ray binaries

    Science.gov (United States)

    Czerny, Bozena; Czerny, Michal; Grindlay, Jonathan E.

    1986-01-01

    Theoretical X-ray spectra of low-mass X-ray binaries with negligible magnetic fields are presented. The geometry of the X-ray emitting region, the energetic efficiency of the accretion in the disk and in the boundary layer which leads to a relation between the disk and the boundary layer luminosities, and the irradiation of the disk by the boundary layer are studied. The model of the radiation spectrum emerging from the neutron star and the innermost part of the disk is presented. The relativistic and Doppler effects and their influence on the spectrum as a function of inclination angle are discussed. A simple method for comparing the spectrum model with observations by studying the hardness ratio is given, and the results for three X-ray sources in globular clusters observed by the Einstein satellite are presented. The range of applicability of the spectrum models is also discussed.

  11. Chandra Studies of Unidentified X-ray Sources in the Galactic Bulge

    Science.gov (United States)

    Mori, Hideyuki

    2013-09-01

    We propose to study a complete X-ray sample in the luminosity range of > 10^34 erg s^-1 in the Galactic bulge, including 5 unidentified sources detected in the ROSAT All Sky Survey. Our goal is to obtain a clear picture about X-ray populations in the bulge, by utilizing the excellent Chandra position accuracy leading to unique optical identification together with the X-ray spectral properties. This is a new step toward understanding the formation history of the bulge. Furthermore, because the luminosity range we observe corresponds to a ``missing link'' region ever studied for a neutron star or blackhole X-ray binary, our results are also unique to test accretion disk theories at intermediate mass accretion rates.

  12. Synthesis and characterisation of ion-implanted epoxy composites for X-ray shielding

    Energy Technology Data Exchange (ETDEWEB)

    Noor Azman, N.Z. [Department of Imaging and Applied Physics, Faculty of Science and Engineering, Curtin University, GPO Box U1987, Perth, WA 6845 (Australia); School of Physics, Universiti Sains Malaysia, 11800 Penang (Malaysia); Siddiqui, S.A. [Department of Imaging and Applied Physics, Faculty of Science and Engineering, Curtin University, GPO Box U1987, Perth, WA 6845 (Australia); Ionescu, M. [Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights, NSW 2234 (Australia); Low, I.M., E-mail: j.low@curtin.edu.au [Department of Imaging and Applied Physics, Faculty of Science and Engineering, Curtin University, GPO Box U1987, Perth, WA 6845 (Australia)

    2012-09-15

    The epoxy samples were implanted with heavy ions such as tungsten (W), gold (Au) and lead (Pb) to investigate the attenuation characteristics of these composites. Near-surface composition depth profiling of ion-implanted epoxy systems was studied using Rutherford Backscattering Spectroscopy (RBS). The effect of implanted ions on the X-ray attenuation was studied with a general diagnostic X-ray machine with X-ray tube voltages from 40 to 100 kV at constant exposure 10 mAs. Results show that the threshold of implanted ions above which X-ray mass attenuation coefficient, {mu}{sub m} of the ion-implanted epoxy composite is distinguishably higher than the {mu}{sub m} of the pure epoxy sample is different for W, Au and Pb.

  13. Measurement of 238U muonic x-rays with a germanium detector setup

    Energy Technology Data Exchange (ETDEWEB)

    Esch, Ernst I [Los Alamos National Laboratory; Jason, Andrew [Los Alamos National Laboratory; Miyadera, Haruo [Los Alamos National Laboratory; Hoteling, Nathan J [Los Alamos National Laboratory; Heffner, Robert H [Los Alamos National Laboratory; Adelmann, Andreas [PAUL SCHERRER INSTITUT; Stocki, Trevor [HEALTH CANADA; Mitchell, Lee [NAVAL RESEARCH LAB

    2009-01-01

    In the field of nuclear non-proliferation muon interactions with materials are of great interest. This paper describes an experiment conducted at the Paul Scherrer Institut (PSI) in Switzerland where a muon beam is stopped in a uranium target. The muons produce characteristic muonic x-rays. Muons will penetrate shielding easily and the produced characteristic x-rays can be used for positive isotope identification. Furthermore, the x-rays for uranium isotopes lie in the energy range of 6-7 MeV, which allows them to have an almost optimal mean free path in heavy shielding such as lead or steel. A measurement was conducted at PSI to prove the feasibility of detecting muonic x-rays from a large sample of depleted uranium (several kilograms) with a germanium detector. In this paper, the experimental setup and analysis of the measurement itself is presented.

  14. Investigation on new scintillators for subnanosecond time-resolved x-ray measurements

    Science.gov (United States)

    Haruki, R.; Shibuya, K.; Nishikido, F.; Koshimizu, M.; Yoda, Y.; Kishimoto, S.

    2010-03-01

    We investigated new x-ray detectors for nuclear resonant scattering measurements with high energy x rays. The organic-inorganic perovskite scintillator of phenethylamine lead halide ((C6H5C2H4NH3)2PbX4) (X:Br, I) was used. These compounds have fast light emission due to an exciton. They include heavy atoms, which make the detector to have high efficiency to high energy x rays. The merit of these scintillators is that we can make a thick crystal compared to a Si wafer which is used in an avalanche photo-diode detector. We successfully measured 67.41 keV x ray signals, the energy of 61Ni nuclear resonant scattering, with high detection efficiency of 42.5 % by the scintillator.

  15. Hard X-ray Detector Calibrations for the FOXSI Sounding Rocket

    Science.gov (United States)

    Lopez, A.; Glesener, L.; Buitrago Casas, J. C.; Han, R.; Ishikawa, S. N.; Christe, S.; Krucker, S.

    2015-12-01

    In the study of high-energy solar flares, detailed X-ray images and spectra of the Sun are required. The Focusing Optics X-ray Solar Imager (FOXSI) sounding rocket experiment is used to test direct-focusing X-ray telescopes and Double-sided Silicon Strip Detectors (DSSD) for solar flare study and to further understand coronal heating. The measurement of active region differential emission measures, flare temperatures, and possible quiet-Sun emission requires a precisely calibrated spectral response. This poster describes recent updates in the calibration of FOXSI's DSSDs based on new calibration tests that were performed after the second flight. The gain for each strip was recalculated using additional radioactive sources. Additionally, the varying strip sensitivity across the detectors was investigated and based on these measurements, the flight images were flatfielded. These improvements lead to more precise X-ray data for future FOXSI flights and show promise for these new technologies in imaging the Sun.

  16. Hard-X-Ray-Induced Multistep Ultrafast Dissociation

    Science.gov (United States)

    Travnikova, Oksana; Marchenko, Tatiana; Goldsztejn, Gildas; Jänkälä, Kari; Sisourat, Nicolas; Carniato, Stéphane; Guillemin, Renaud; Journel, Loïc; Céolin, Denis; Püttner, Ralph; Iwayama, Hiroshi; Shigemasa, Eiji; Piancastelli, Maria Novella; Simon, Marc

    2016-05-01

    Creation of deep core holes with very short (τ ≤1 fs ) lifetimes triggers a chain of relaxation events leading to extensive nuclear dynamics on a few-femtosecond time scale. Here we demonstrate a general multistep ultrafast dissociation on an example of HCl following Cl 1 s →σ* excitation. Intermediate states with one or multiple holes in the shallower core electron shells are generated in the course of the decay cascades. The repulsive character and large gradients of the potential energy surfaces of these intermediates enable ultrafast fragmentation after the absorption of a hard x-ray photon.

  17. Elemental analysis by means of X-ray attenuation measurements

    Science.gov (United States)

    Cesareo, Roberto; Giannini, Marino

    1980-03-01

    Radioactive sources of 109Cd, 241Am and 57Co were employed to measure the attenuation coefficient of biological materials such as whole blood, red blood cells, plasma, urine, water and of materials of interest for computed tomography, such as plexiglas, polyethylene, nylon, teflon, etc. The experimental errors range between 0.3% and 1%. A method is also presented which allows quantitative analysis of materials by measuring their attenuation coefficient at various monoenergetic X-ray energies. As an example, attenuation measurements at 60 keV and 122 keV were employed in order to determine the concentration of lead and copper in silver alloys.

  18. X-ray Probes of Magnetospheric Interactions with Jupiter's Auroral zones, the Galilean Satellites, and the Io Plasma Torus

    Science.gov (United States)

    Elsner, R. F.; Ramsey, B. D.; Waite, J. H., Jr.; Rehak, P.; Johnson, R. E.; Cooper, J. F.; Swartz, D. A.

    2004-01-01

    Remote observations with the Chandra X-ray Observatory and the XMM-Newton Observatory have shown that the Jovian system is a source of x-rays with a rich and complicated structure. The planet's polar auroral zones and its disk are powerful sources of x-ray emission. Chandra observations revealed x-ray emission from the Io Plasma Torus and from the Galilean moons Io, Europa, and possibly Ganymede. The emission from these moons is certainly due to bombardment of their surfaces of highly energetic protons, oxygen and sulfur ions from the region near the Torus exciting atoms in their surfaces and leading to fluorescent x-ray emission lines. Although the x-ray emission from the Galilean moons is faint when observed fiom Earth orbit, an imaging x-ray spectrometer in orbit around these moons, operating at 200 eV and above with 150 eV energy resolution, would provide a detailed mapping (down to 40 m spatial resolution) of the elemental composition in their surfaces. Here we describe the physical processes leading to x-ray emission fiom the surfaces of Jupiter's moons and the instrumental properties, as well as energetic ion flux models or measurements, required to map the elemental composition of their surfaces. We discuss the proposed scenarios leading to possible surface compositions. For Europa, the two most extreme are (1) a patina produced by exogenic processes such as meteoroid bombardment and ion implantation, and (2) upwelling of material fiom the subsurface ocean. We also describe the characteristics of X - m , an imaging x-ray spectrometer under going a feasibility study for the JIM0 mission, with the ultimate goal of providing unprecedented x-ray studies of the elemental composition of the surfaces of Jupiter's icy moons and Io, as well as of Jupiter's auroral x-ray emission.

  19. The imaging of nanostructures with novel x-ray methods

    Science.gov (United States)

    Dietze, Sebastian

    -hand and left-hand circular polarization. These methods lead to very similar results for the magnetic domain reconstruction, proving the viability of this technique. Thus, dichroic CDI may be applied to a much wider class of materials than was previously possible. Finally, persistent photocoductivity was induced during nano-diffraction. The resistivity of vanadium dioxide (VO2) decreased by over one-order of magnitude upon localized illumination with x-rays at room temperature. Despite this reduction, the structure remained in the monoclinic phase and had no signature of the high-temperature tetragonal phase that is usually associated with the lower resistance. Once illumination ceased, relaxation to the insulating state took tens of hours near room temperature. However, a full recovery of the insulating state was achieved within minutes by thermal cycling. This behavior is consistent with random local-potential fluctuations and random distribution of discrete recombination sites used to model residual photoconductivity.

  20. Next Generation X-ray Polarimeter

    Science.gov (United States)

    Hill-Kittle, Joe

    The emission regions of many types of X-ray sources are small and cannot be spatially resolved without interferometry techniques that haven't yet been developed. In order to understand the emission mechanisms and emission geometry, alternate measurement techniques are required. Most microphysical processes that affect X-rays, including scattering and magnetic emission processes are imprinted as polarization signatures. X-ray polarization also reveals exotic physical processes occurring in regions of very strong gravitational and magnetic fields. Observations of X-ray polarization will provide a measurement of the geometrical distribution of gas and magnetic fields without foreground depolarization that affects longer wavelengths (e.g. Faraday rotation in the radio). Emission from accretion disks has an inclination-dependent polarization. The polarization signature is modified by extreme gravitational forces, which bend light, essentially changing the contribution of each part of the disk to the integrated total intensity seen by distant observers. Because gravity has the largest effect on the innermost parts of the disk (which are the hottest, and thus contributes to more high energy photons), the energy dependent polarization is diagnostic of disk inclination, black hole mass and spin. Increasing the sensitive energy band will make these measurements possible. X-ray polarimetry will also enable the study of the origin of cosmic rays in the universe, the nature of black holes, the role of black holes in the evolution of galaxies, and the interaction of matter with the highest physically possible magnetic fields. These objectives address NASA's strategic interest in the origin, structure, and evolution of the universe. We propose a two-year effort to develop the Next Generation X-ray Polarimeter (NGXP) that will have more than ten times the sensitivity of the current state of the art. NGXP will make possible game changing measurements of classes of astrophysical

  1. Analytical characterization of a new mobile X-ray fluorescence and X-ray diffraction instrument combined with a pigment identification case study

    Energy Technology Data Exchange (ETDEWEB)

    Van de Voorde, Lien, E-mail: lien.vandevoorde@ugent.be [Ghent University, Department of Analytical Chemistry, X-ray Microspectroscopy and Imaging Research Group, Krijgslaan 281 S12, B-9000 Gent (Belgium); Vekemans, Bart [Ghent University, Department of Analytical Chemistry, X-ray Microspectroscopy and Imaging Research Group, Krijgslaan 281 S12, B-9000 Gent (Belgium); Verhaeven, Eddy [Antwerp University, Faculty of Design Sciences, Mutsaardstraat 31, B-2000 Antwerpen (Belgium); Tack, Pieter; De Wolf, Robin; Garrevoet, Jan [Ghent University, Department of Analytical Chemistry, X-ray Microspectroscopy and Imaging Research Group, Krijgslaan 281 S12, B-9000 Gent (Belgium); Vandenabeele, Peter [Ghent University, Department of Archaeology, Archaeometry Research Group, Sint-Pietersnieuwstraat 35, B-9000 Gent (Belgium); Vincze, Laszlo [Ghent University, Department of Analytical Chemistry, X-ray Microspectroscopy and Imaging Research Group, Krijgslaan 281 S12, B-9000 Gent (Belgium)

    2015-08-01

    A new, commercially available, mobile system combining X-ray diffraction and X-ray fluorescence has been evaluated which enables both elemental analysis and phase identification simultaneously. The instrument makes use of a copper or molybdenum based miniature X-ray tube and a silicon-Pin diode energy-dispersive detector to count the photons originating from the samples. The X-ray tube and detector are both mounted on an X-ray diffraction protractor in a Bragg–Brentano θ:θ geometry. The mobile instrument is one of the lightest and most compact instruments of its kind (3.5 kg) and it is thus very useful for in situ purposes such as the direct (non-destructive) analysis of cultural heritage objects which need to be analyzed on site without any displacement. The supplied software allows both the operation of the instrument for data collection and in-depth data analysis using the International Centre for Diffraction Data database. This paper focuses on the characterization of the instrument, combined with a case study on pigment identification and an illustrative example for the analysis of lead alloyed printing letters. The results show that this commercially available light-weight instrument is able to identify the main crystalline phases non-destructively, present in a variety of samples, with a high degree of flexibility regarding sample size and position. - Highlights: • New X-ray fluorescence and X-ray diffraction instrument for non-destructive analysis • Commercially available, mobile system • One of the lightest and most compact of its kind • Characterization, data acquisition and analysis are performed. • Results of measurements on pigment model samples and cultural heritage materials.

  2. Formation and evolution of X-ray binaries

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    We review recent progress in theoretical understanding of X-ray binaries,which has largely been driven by new observations.We select several topics including formation of compact low-mass X-ray binaries,the evolutionary connection between low-mass X-ray binaries and binary and millisecond radio pulsars,and ultraluminous X-ray sources,to illustrate the interplay between theories and observations.

  3. Synergy between X-ray and infrared observations

    CERN Document Server

    Alexander, D M

    2016-01-01

    We briefly review the synergy between X-ray and infrared observations for Active Galactic Nuclei (AGNs) detected in cosmic X-ray surveys, primarily with XMM-Newton, Chandra, and NuSTAR. We focus on two complementary aspects of this X-ray-infrared synergy (1) the identification of the most heavily obscured AGNs and (2) the connection between star formation and AGN activity. We also briefly discuss future prospects for X-ray-infrared studies over the next decade.

  4. Be-Phenomenon in Neutron Star X-ray Binaries

    Science.gov (United States)

    Kühnel, M.; Kretschmar, P.; Fürst, F.; Pottschmidt, K.; Hemphill, P.; Rothschild, R. E.; Okazaki, A. T.; Sagredo, M.; Wilms, J.

    2017-02-01

    In this work we provide a brief insight into two aspects of Be/X-ray binaries, which are probably involved in production of X-ray outbursts: the evolution of the Be star disk, in particular of its size, and the binary geometry which drives gravitational interaction. Simultaneous X-ray and optical data will aid our investigation of the evolution of Be stars in binaries and the X-ray outburst mechanism.

  5. SZ/X-ray scaling relations using X-ray data and Planck Nominal maps

    Science.gov (United States)

    De Martino, I.; Atrio-Barandela, F.

    2016-09-01

    We determine the relation between the Comptonization parameter predicted using X-ray data YC, Xray and the X-ray luminosity LX, both magnitudes derived from ROSAT data, with the Comptonization parameter YC, SZ measured on Planck 2013 foreground cleaned Nominal maps. The 560 clusters of our sample includes clusters with masses M ≥ 1013 M⊙, one order of magnitude smaller than those used by the Planck Collaboration in a similar analysis. It also contains eight times more clusters in the redshift interval z ≤ 0.3. The prediction of the β = 2/3 model convolved with the Planck antenna beam agrees with the anisotropies measured in foreground cleaned Planck Nominal maps within the X-ray emitting region, confirming the results of an earlier analysis. The universal pressure profile overestimates the signal by a 15-21 per cent depending on the angular aperture. We show that the discrepancy is not due to the presence of cool-core systems but it is an indication of a brake in the LX - M relation towards low mass systems. We show that relation of the Comptonization parameter averaged over the region that emits 99 per cent of the X-ray flux and and the X-ray luminosity is consistent with the predictions of the self-similar model. We confirm previous findings that the scaling relations studied here do not evolve with redshift within the range probed by our catalogue.

  6. 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

    We present spectroscopic X-ray data of two candidate ultracompact X-ray binaries (UCXBs): 4U 0614+091 and 4U 1543-624. We confirm the presence of a broad O viii Ly alpha reflection line (at a parts per thousand 18 angstrom) using XMM-Newton and Chandra observations obtained in 2012 and 2013....... The 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...

  7. X-ray Properties of an Unbiased Hard X-ray Detected Sample of AGN

    Science.gov (United States)

    Winter, Lisa M.; Mushotzky, Richard F.; Tueller, Jack; Markwardt, Craig

    2007-01-01

    The SWIFT gamma ray observatory's Burst Alert Telescope (BAT) has detected a sample of active galactic nuclei (AGN) based solely on their hard X-ray flux (14-195keV). In this paper, we present for the first time XMM-Newton X-ray spectra for 22 BAT AGXs with no previously analyzed X-ray spectra. If our sources are a representative sample of the BAT AGN, as we claim, our results present for the first time global X-ray properties of an unbiased towards absorption (n(sub H) = 0.03), AGN sample. We find 9/22 low absorption (n(sub H) 2.0 keV. Five of the complex sources (NGC 612, ESO 362-G018, MRK 417, ESO 506-G027, and NGC 6860) are classified as Compton-thick candidates. Further, we find four more sources (SWIFT J0641.3+3257, SWIFT J0911.2+4533, SWIFT J1200.8+0650, and NGC 4992) with properties consistent with the hidden/buried AGN reported by Ueda et al. (2007). Finally, we include a comparison of the XMM EPIC spectra with available SWIFT X-ray Telescope (XRT) observations. From these comparisons, we find 6/16 sources with varying column densities, 6/16 sources with varying power law indices, and 13/16 sources with varying fluxes, over periods of hours to months. Flux and power law index are correlated for objects where both parameters vary.

  8. RXTE detects X-ray bursts from Circinus X-1

    NARCIS (Netherlands)

    Linares, M.; Soleri, P.; Watts, A.; Altamirano, D.; Armas-Padilla, M.; Cavecchi, Y.; Degenaar, N.; Kalamkar, M.; Kaur, R.; van der Klis, M.; Patruno, A.; Wijnands, R.; Yang, Y.; Casella, P.; Rea, N.

    2010-01-01

    After the recent report of X-ray re-brightening (ATel #2608), RXTE has observed the peculiar neutron star X-ray binary Cir X-1 eleven times during the last two weeks (May 11-25, 2010). We report the detection of nine X-ray bursts in RXTE-PCA data, 25 years after the first -and the only previous- det

  9. Obscuring Supersoft X-ray Sources in Stellar Winds

    DEFF Research Database (Denmark)

    Nielsen, Mikkel Thomas Bøje; Dominik, Carsten; Nelemans, Gijs

    2011-01-01

    We investigate the possibility of obscuring supersoft X-ray sources in the winds of companion stars. We derive limits on the amount of circumstellar material needed to fully obscure a 'canonical' supersoft X-ray source in the Large Magellanic Cloud, as observed with the Chandra X-ray Observatory....

  10. X-ray holographic microscopy: Improved images of zymogen granules

    Energy Technology Data Exchange (ETDEWEB)

    Jacobsen, C.; Howells, M.; Kirz, J.; McQuaid, K.; Rothman, S.

    1988-10-01

    Soft x-ray holography has long been considered as a technique for x-ray microscopy. It has been only recently, however, that sub-micron resolution has been obtained in x-ray holography. This paper will concentrate on recent progress we have made in obtaining reconstructed images of improved quality. 15 refs., 6 figs.

  11. Phosphor Scanner For Imaging X-Ray Diffraction

    Science.gov (United States)

    Carter, Daniel C.; Hecht, Diana L.; Witherow, William K.

    1992-01-01

    Improved optoelectronic scanning apparatus generates digitized image of x-ray image recorded in phosphor. Scanning fiber-optic probe supplies laser light stimulating luminescence in areas of phosphor exposed to x rays. Luminescence passes through probe and fiber to integrating sphere and photomultiplier. Sensitivity and resolution exceed previously available scanners. Intended for use in x-ray crystallography, medical radiography, and molecular biology.

  12. X-Ray Exam: Lower Leg (Tibia and Fibula)

    Science.gov (United States)

    ... 2-Year-Old X-Ray Exam: Lower Leg (Tibia and Fibula) KidsHealth > For Parents > X-Ray Exam: Lower Leg (Tibia and Fibula) A A A What's in this ... Child If You Have Questions en español Radiografía: tibia y peroné What It Is An X-ray ...

  13. X-Ray Exam: Bone Age Study (For Parents)

    Science.gov (United States)

    ... Old Feeding Your 1- to 2-Year-Old X-Ray Exam: Bone Age Study KidsHealth > For Parents > X-Ray Exam: Bone Age Study A A A ... system. It's usually done by taking a single X-ray of the left wrist, hand, and fingers. ...

  14. X-ray Pulsar in the Crab Nebula.

    Science.gov (United States)

    Fritz, G; Henry, R C; Meekins, J F; Chubb, T A; Friedman, H

    1969-05-09

    X-ray pulsations have been observed in the Crab Nebula at a frequency closely matching the radio and optical pulsations. About 5 percent of the total x-ray power of the nebula appears in the pulsed component. The x-ray pulsations have the form of a main pulse and an interpulse separated by about 12 milliseconds.

  15. Compact X-ray Sources in Nearby Galaxy Nuclei

    CERN Document Server

    Colbert, E J M

    1998-01-01

    We have found compact, near-nuclear X-ray sources in 21 (54\\%) of a complete sample of 39 nearby face-on spiral and elliptical galaxies with available ROSAT HRI data. ROSAT X-ray luminosities (0.2 $-$ 2.4 keV) of these compact X-ray sources are $\\sim$10$^{37}

  16. Broad-band hard X-ray reflectors

    DEFF Research Database (Denmark)

    Joensen, K.D.; Gorenstein, P.; Hoghoj, P.;

    1997-01-01

    Interest in optics for hard X-ray broad-band application is growing. In this paper, we compare the hard X-ray (20-100 keV) reflectivity obtained with an energy-dispersive reflectometer, of a standard commercial gold thin-film with that of a 600 bilayer W/Si X-ray supermirror. The reflectivity of ...

  17. INTEGRAL monitoring of unusually long X-ray bursts

    DEFF Research Database (Denmark)

    Chenevez, Jérôme; Falanga, M.; Kuulkers, E.;

    2008-01-01

    X-ray bursts are thermonuclear explosions on the surface of accreting neutron stars in X-ray binaries. As most of the known X-ray bursters are frequently observed by INTEGRAL, an international collaboration have been taking advantage of its instrumentation to specifically monitor the occurrence...

  18. X-ray Polarization Probes of SNR and PWN

    Science.gov (United States)

    Romani, Roger W.

    2016-04-01

    X-ray synchrotron radiation traces the high energy extrema of e+/e- accelerated by pulsar magnetospheres and supernova shocks. X-ray polarization lets us probe the unresolved geometry of these relativistic shock structures. I summarize what we know about magnetic field geometries in these nebulae and the prospects for learning more from X-ray polarimetry.

  19. 14th International Conference on X-Ray Lasers

    CERN Document Server

    Menoni, Carmen; Marconi, Mario

    2016-01-01

    These proceedings comprise invited and contributed papers presented at the 14th International Conference on X-Ray Lasers (ICXRL 2014). This conference is part of a continuing series dedicated to recent developments and applications of x-ray lasers and other coherent x-ray sources with attention to supporting technologies and instrumentation. New results in the generation of intense, coherent x-rays and progress toward practical devices and their applications in numerous fields are reported. Areas of research in plasma-based x-ray lasers, 4th generation accelerator-based sources and higher harmonic generation, and other x-ray generation schemes are covered.  The scope of ICXRL 2014 included, but was not limited to: Laser-pumped X-ray lasers Discharge excitation and other X-ray laser pumping methods Injection/seeding of X-ray amplifiers New lasing transitions and novel X-ray laser schemes High Harmonic sources-Free-electron laser generation in the XUV and X-ray range Novel schemes for coherent XUV and X-ray ge...

  20. Resonant x-ray scattering in correlated systems

    CERN Document Server

    Ishihara, Sumio

    2017-01-01

    The research and its outcomes presented here is devoted to the use of x-ray scattering to study correlated electron systems and magnetism. Different x-ray based methods are provided to analyze three dimensional electron systems and the structure of transition-metal oxides. Finally the observation of multipole orderings with x-ray diffraction is shown.

  1. X-Rays from Saturn and its Rings

    Science.gov (United States)

    Bhardwaj, Anil; Elsner, Ron F.; Waite, J. Hunter; Gladstone, G. Randall; Cravens, Tom E.; Ford, Peter G.

    2005-01-01

    In January 2004 Saturn was observed by Chandra ACIS-S in two exposures, 00:06 to 11:00 UT on 20 January and 14:32 UT on 26 January to 01:13 UT on 27 January. Each continuous observation lasted for about one full Saturn rotation. These observations detected an X-ray flare from the Saturn's disk and indicate that the entire Saturnian X-ray emission is highly variable -- a factor of $\\sim$4 variability in brightness in a week time. The Saturn X-ray flare has a time and magnitude matching feature with the solar X-ray flare, which suggests that the disk X-ray emission of Saturn is governed by processes happening on the Sun. These observations also unambiguously detected X-rays from Saturn's rings. The X-ray emissions from rings are present mainly in the 0.45-0.6 keV band centered on the atomic OK$\\alpha$ fluorescence line at 525 eV: indicating the production of X-rays due to oxygen atoms in the water icy rings. The characteristics of X-rays from Saturn's polar region appear to be statistically consistent with those from its disk X-rays, suggesting that X-ray emission from the polar cap region might be an extension of the Saturn disk X-ray emission.

  2. Focusing high-energy x-rays by a PMMA compound x-ray lens on Beijing synchrotron radiation facility

    Institute of Scientific and Technical Information of China (English)

    Le Zi-Chun; Liang Jing-Qiu; Dong Wen; Zhu Pei-Ping; Peng Liang-Qiang; Wang Wei-Biao; Huang Wan-Xia; Yuan Qing-Xi; Wang Jun-Yue

    2007-01-01

    The x-ray compound lens is a novel refractive x-ray optical device. This paper reports the authors' recent research on a polymethyl methacrylate (PMMA) compound x-ray lens. Firstly the designing and LIGA fabrication process for the PMMA compound x-ray lens are briefly described. Then, a method for theoretical analysis, as well as the experimental system for measurement is also introduced. Finally, the focusing spots for 8keV monochromatic x-rays by the PMMA compound x-ray lens are measured and analysed. According to the experimental results, it is concluded that the PMMA compound x-ray lens promises a good focusing performance under the high-energy x-rays.

  3. Stig Sundell at the bent crystal X-ray spectrometer for the X-ray shift experiment.

    CERN Multimedia

    1976-01-01

    The bent crystal X-ray spectrometer is being used to measure small shifts in the frequencies of X-rays emitted from the lower electron energy levels, in order to learn about the size of the nuclei concerned

  4. Making use of x-ray optical effects in photoelectron-, Auger electron-, and x-ray emission spectroscopies: Total reflection, standing-wave excitation, and resonant effects

    Energy Technology Data Exchange (ETDEWEB)

    Yang, S.-H. [IBM Almaden Research Center, San Jose, California 95120 (United States); Gray, A. X. [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94740 (United States); Department of Physics, University of California at Davis, Davis, California 95616 (United States); Stanford Institute for Materials and Energy Science, Stanford University and SLAC National Accelerator Laboratory, Menlo Park, California 94025 (United States); Kaiser, A. M. [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94740 (United States); Department of Physics, University of California at Davis, Davis, California 95616 (United States); Peter Grunberg Institute, PGI-6, Forschungszentrum Juelich, 52425 Juelich (Germany); Mun, B. S. [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Department of Applied Physics, Hanyang University, Ansan, Gyeonggi 426-791 (Korea, Republic of); Sell, B. C. [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94740 (United States); Department of Physics, University of California at Davis, Davis, California 95616 (United States); Department of Physics, Otterbein College, Westerville, Ohio 43081 (United States); Kortright, J. B. [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94740 (United States); Fadley, C. S. [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94740 (United States); Department of Physics, University of California at Davis, Davis, California 95616 (United States)

    2013-02-21

    We present a general theoretical methodology and related open-access computer program for carrying out the calculation of photoelectron, Auger electron, and x-ray emission intensities in the presence of several x-ray optical effects, including total reflection at grazing incidence, excitation with standing-waves produced by reflection from synthetic multilayers and at core-level resonance conditions, and the use of variable polarization to produce magnetic circular dichroism. Calculations illustrating all of these effects are presented, including in some cases comparisons to experimental results. Sample types include both semi-infinite flat surfaces and arbitrary multilayer configurations, with interdiffusion/roughness at their interfaces. These x-ray optical effects can significantly alter observed photoelectron, Auger, and x-ray intensities, and in fact lead to several generally useful techniques for enhancing surface and buried-layer sensitivity, including layer-resolved densities of states and depth profiles of element-specific magnetization. The computer program used in this study should thus be useful for a broad range of studies in which x-ray optical effects are involved or are to be exploited in next-generation surface and interface studies of nanoscale systems.

  5. X-Ray Comb Generation from Nuclear-Resonance-Stabilized X-Ray Free-Electron Laser Oscillator for Fundamental Physics and Precision Metrology

    Energy Technology Data Exchange (ETDEWEB)

    Adams, B. W.; Kim, K. -J.

    2015-03-31

    An x-ray free-electron laser oscillator (XFELO) is a next-generation x-ray source, similar to free-electron laser oscillators at VUV and longer wavelengths but using crystals as high-reflectivity x-ray mirrors. Each output pulse from an XFELO is fully coherent with high spectral purity. The temporal coherence length can further be increased drastically, from picoseconds to microseconds or even longer, by phase-locking successive XFELO output pulses, using the narrow nuclear resonance lines of nuclei such as Fe-57 as a reference. We show that the phase fluctuation due to the seismic activities is controllable and that due to spontaneous emission is small. The fluctuation of electron-bunch spacing contributes mainly to the envelope fluctuation but not to the phase fluctuation. By counting the number of standing-wave maxima formed by the output of the nuclear-resonance-stabilized (NRS) XFELO over an optically known length, the wavelength of the nuclear resonance can be accurately measured, possibly leading to a new length or frequency standard at x-ray wavelengths. A NRS-XFELO will be an ideal source for experimental x-ray quantum optics as well as other fundamental physics. The technique can be refined for other, narrower resonances such as Ta-181 or Sc-45.

  6. X-ray Cryogenic Facility (XRCF) Handbook

    Science.gov (United States)

    Kegley, Jeffrey R.

    2016-01-01

    The X-ray & Cryogenic Facility (XRCF) Handbook is a guide for planning operations at the facility. A summary of the capabilities, policies, and procedures is provided to enhance project coordination between the facility user and XRCF personnel. This handbook includes basic information that will enable the XRCF to effectively plan and support test activities. In addition, this handbook describes the facilities and systems available at the XRCF for supporting test operations. 1.2 General Facility Description The XRCF was built in 1989 to meet the stringent requirements associated with calibration of X-ray optics, instruments, and telescopes and was subsequently modified in 1999 & 2005 to perform the challenging cryogenic verification of Ultraviolet, Optical, and Infrared mirrors. These unique and premier specialty capabilities, coupled with its ability to meet multiple generic thermal vacuum test requirements for large payloads, make the XRCF the most versatile and adaptable space environmental test facility in the Agency. XRCF is also recognized as the newest, most cost effective, most highly utilized facility in the portfolio and as one of only five NASA facilities having unique capabilities. The XRCF is capable of supporting and has supported missions during all phases from technology development to flight verification. Programs/projects that have benefited from XRCF include Chandra, Solar X-ray Imager, Hinode, and James Webb Space Telescope. All test programs have been completed on-schedule and within budget and have experienced no delays due to facility readiness or failures. XRCF is currently supporting Strategic Astrophysics Technology Development for Cosmic Origins. Throughout the years, XRCF has partnered with and continues to maintain positive working relationships with organizations such as ATK, Ball Aerospace, Northrop Grumman Aerospace, Excelis (formerly Kodak/ITT), Smithsonian Astrophysical Observatory, Goddard Space Flight Center, University of Alabama

  7. Quantitative cone beam X-ray luminescence tomography/X-ray computed tomography imaging

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Dongmei; Zhu, Shouping, E-mail: zhusp2009@gmail.com; Chen, Xueli; Chao, Tiantian; Cao, Xu; Zhao, Fengjun; Huang, Liyu; Liang, Jimin [Engineering Research Center of Molecular and Neuro Imaging of Ministry of Education and School of Life Science and Technology, Xidian University, Xi' an, Shaanxi 710071 (China)

    2014-11-10

    X-ray luminescence tomography (XLT) is an imaging technology based on X-ray-excitable materials. The main purpose of this paper is to obtain quantitative luminescence concentration using the structural information of the X-ray computed tomography (XCT) in the hybrid cone beam XLT/XCT system. A multi-wavelength luminescence cone beam XLT method with the structural a priori information is presented to relieve the severe ill-posedness problem in the cone beam XLT. The nanophosphors and phantom experiments were undertaken to access the linear relationship of the system response. Then, an in vivo mouse experiment was conducted. The in vivo experimental results show that the recovered concentration error as low as 6.67% with the location error of 0.85 mm can be achieved. The results demonstrate that the proposed method can accurately recover the nanophosphor inclusion and realize the quantitative imaging.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-05-01

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

  9. Fundamental x-ray interaction limits in diagnostic imaging detectors: spatial resolution.

    Science.gov (United States)

    Hajdok, G; Battista, J J; Cunningham, I A

    2008-07-01

    The practice of diagnostic x-ray imaging has been transformed with the emergence of digital detector technology. Although digital systems offer many practical advantages over conventional film-based systems, their spatial resolution performance can be a limitation. The authors present a Monte Carlo study to determine fundamental resolution limits caused by x-ray interactions in four converter materials: Amorphous silicon (a-Si), amorphous selenium, cesium iodide, and lead iodide. The "x-ray interaction" modulation transfer function (MTF) was determined for each material and compared in terms of the 50% MTF spatial frequency and Wagner's effective aperture for incident photon energies between 10 and 150 keV and various converter thicknesses. Several conclusions can be drawn from their Monte Carlo study. (i) In low-Z (a-Si) converters, reabsorption of Compton scatter x rays limits spatial resolution with a sharp MTF drop at very low spatial frequencies (x rays plays a dominant role, resulting in a mid-frequency (1-5 cycles/mm) MTF drop. (ii) Coherent scatter plays a minor role in the x-ray interaction MTF. (iii) The spread of energy due to secondary electron (e.g., photoelectrons) transport is significant only at very high spatial frequencies. (iv) Unlike the spread of optical light in phosphors, the spread of absorbed energy from x-ray interactions does not significantly degrade spatial resolution as converter thickness is increased. (v) The effective aperture results reported here represent fundamental spatial resolution limits of the materials tested and serve as target benchmarks for the design and development of future digital x-ray detectors.

  10. Modeling and characterization of X-ray yield in a polychromatic, lab-scale, X-ray computed tomography system

    Energy Technology Data Exchange (ETDEWEB)

    Mertens, J.C.E.; Chawla, Nikhilesh, E-mail: nchawla@asu.edu

    2015-05-21

    A modular X-ray computed micro-tomography (µXCT) system is characterized in terms of X-ray yield resulting both from the generated X-ray spectrum and from X-ray detection with an energy-sensitive detector. The X-ray computed tomography system is composed of a commercially available cone-beam microfocus X-ray source and a modular optically-coupled-CCD-scintillator X-ray detector. The X-ray yield is measured and reported in units independent from exposure time, X-ray tube beam target current, and cone-beam-to-detector geometry. The polychromatic X-ray source is modeled as a broad Bremsstrahlung X-ray spectrum in order to understand the effect of the controllable parameters, that is, X-ray tube accelerating voltage and X-ray beam filtering. An approach is adopted which expresses the absolute number of emitted X-rays. The response of the energy-sensitive detector to the modeled spectrum is modeled as a function of scintillator composition and thickness. The detection efficiency model for the polychromatic X-ray detector considers the response of the light collection system and the electronic imaging array in order to predict absolute count yield under the studied conditions. The modeling approach is applied to the specific hardware implemented in the current µXCT system. The model's predictions for absolute detection rate are in reasonable agreement with measured values under a range of conditions applied to the system for X-ray microtomography imaging, particularly for the LuAG:Ce scintillator material.

  11. X-ray pinhole camera setups used in the Atomki ECR Laboratory for plasma diagnostics.

    Science.gov (United States)

    Rácz, R; Biri, S; Pálinkás, J; Mascali, D; Castro, G; Caliri, C; Romano, F P; Gammino, S

    2016-02-01

    Imaging of the electron cyclotron resonance (ECR) plasmas by using CCD camera in combination with a pinhole is a non-destructive diagnostics method to record the strongly inhomogeneous spatial density distribution of the X-ray emitted by the plasma and by the chamber walls. This method can provide information on the location of the collisions between warm electrons and multiple charged ions/atoms, opening the possibility to investigate the direct effect of the ion source tuning parameters to the plasma structure. The first successful experiment with a pinhole X-ray camera was carried out in the Atomki ECR Laboratory more than 10 years ago. The goal of that experiment was to make the first ECR X-ray photos and to carry out simple studies on the effect of some setting parameters (magnetic field, extraction, disc voltage, gas mixing, etc.). Recently, intensive efforts were taken to investigate now the effect of different RF resonant modes to the plasma structure. Comparing to the 2002 experiment, this campaign used wider instrumental stock: CCD camera with a lead pinhole was placed at the injection side allowing X-ray imaging and beam extraction simultaneously. Additionally, Silicon Drift Detector (SDD) and High Purity Germanium (HPGe) detectors were installed to characterize the volumetric X-ray emission rate caused by the warm and hot electron domains. In this paper, detailed comparison study on the two X-ray camera and detector setups and also on the technical and scientific goals of the experiments is presented.

  12. A broadband x-ray imaging spectroscopy with high-angular resolution: the FORCE mission

    Science.gov (United States)

    Mori, Koji; Tsuru, Takeshi Go; Nakazawa, Kazuhiro; Ueda, Yoshihiro; Okajima, Takashi; Murakami, Hiroshi; Awaki, Hisamitsu; Matsumoto, Hironori; Fukazawa, Yasushi; Tsunemi, Hiroshi; Takahashi, Tadayuki; Zhang, William W.

    2016-07-01

    We are proposing FORCE (Focusing On Relativistic universe and Cosmic Evolution) as a future Japan-lead Xray observatory to be launched in the mid 2020s. Hitomi (ASTRO-H) possesses a suite of sensitive instruments enabling the highest energy-resolution spectroscopy in soft X-ray band, a broadband X-ray imaging spectroscopy in soft and hard X-ray bands, and further high energy coverage up to soft gamma-ray band. FORCE is the direct successor to the broadband X-ray imaging spectroscopy aspect of Hitomi (ASTRO-H) with significantly higher angular resolution. The current design of FORCE defines energy band pass of 1-80 keV with angular resolution of black holes" in various mass-scales: "buried supermassive black holes (SMBHs)" (> 104 M⊙) residing in the center of galaxies in a cosmological distance, "intermediate-mass black holes" (102-104 M⊙) acting as the possible seeds from which SMBHs grow, and "orphan stellar-mass black holes" (mirror and wide-band X-ray detector. The focal length is currently planned to be 10 m. The silicon mirror with multi-layer coating is our primary choice to achieve lightweight, good angular optics. The detector is a descendant of hard X-ray imager onboard Hitomi (ASTRO-H) replacing its silicon strip detector with SOI-CMOS silicon pixel detector, allowing an extension of the low energy threshold down to 1 keV or even less.

  13. From zone plate to microcalorimeter . 50 years of cosmic X-ray spectroscopy at SRON

    Science.gov (United States)

    Bleeker, J.; Verbunt, F.

    The first method used by the SRON Laboratory for Space Research at Utrecht to spectroscopically image the Sun in X-rays employed Fresnel zone plates. Four Fresnel plates, covering four specific wavelengths, were flown on an Aerobee rocket in 1967 and gave a first useful X-ray image of the Sun in the Si-X line at 51 Å. The technique developed for the solar X-ray images enabled SRON to become the Lead Investigator for the grating spectrographs on several major X-ray satellites, i.e. on the Einstein and EXOSAT satellites, launched in November 1978 and May 1983 respectively, and on the Chandra and XMM-Newton observatories both launched in 1999. Since then, a considerable effort was put into the development of cryogenically cooled, non-dispersive X-ray spectrometers as model payload elements for the XEUS, IXO and Athena mission studies. This paper briefly reviews these developments, highlights some of the resulting scientific insights and offers a few thoughts on the present outlook for a next generation X-ray observatory. The biggest challenge for the realization of such a mission is not primarily technical: global coordination and collaboration, both among scientists and the major space agencies, is a prerequisite for a successful next major leap in this discipline.

  14. A toy model for X-ray spectral variability of active galactic nuclei

    CERN Document Server

    Cao, Xinwu

    2014-01-01

    The long term X-ray spectral variability of ten active galactic nuclei (AGN) shows a positive spectral index-flux correlation for each object (Sobolewska & Papadakis 2009). An inner advection dominated accretion flow (ADAF) may connect to a thin disc/corona at a certain transition radius, which are responsible for hard X-ray emission in AGN. The ADAF is hot and its X-ray spectrum is hard, while the corona above the disc is relatively cold and its X-ray spectrum is therefore soft. The radiation efficiency of the ADAF is usually much lower than that of the thin disc. The increase of the transition radius may lead to decreases of the spectral index (i.e., a hard spectrum) and the X-ray luminosity even if the accretion rate is fixed, and vice versa. We propose that such X-ray variability is caused by the change of the transition radius. Our model calculations can reproduce the observed index-flux correlations, if the transition radius fluctuates around an equilibrium position, and the radiation efficiency of ...

  15. Scattering-compensated cone beam x-ray luminescence computed tomography

    Science.gov (United States)

    Gao, Peng; Rong, Junyan; Pu, Huangsheng; Liu, Wenlei; Liao, Qimei; Lu, Hongbing

    2016-04-01

    X-ray luminescence computed tomography (XLCT) opens new possibilities to perform molecular imaging with x-ray. It is a dual modality imaging technique based on the principle that some nanophosphors can emit near-infrared (NIR) light when excited by x-rays. The x-ray scattering effect is a great issue in both CT and XLCT reconstruction. It has been shown that if the scattering effect compensated, the reconstruction average relative error can be reduced from 40% to 12% in the in the pencil beam XLCT. However, the scattering effect in the cone beam XLCT has not been proved. To verify and reduce the scattering effect, we proposed scattering-compensated cone beam x-ray luminescence computed tomography using an added leading to prevent the spare x-ray outside the irradiated phantom in order to decrease the scattering effect. Phantom experiments of two tubes filled with Y2O3:Eu3+ indicated that the proposed method could reduce the scattering by a degree of 30% and can reduce the location error from 1.8mm to 1.2mm. Hence, the proposed method was feasible to the general case and actual experiments and it is easy to implement.

  16. X-ray pinhole camera setups used in the Atomki ECR Laboratory for plasma diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Rácz, R., E-mail: rracz@atomki.hu; Biri, S.; Pálinkás, J. [Institute for Nuclear Research (Atomki), Hungarian Academy of Sciences, Bem tér 18/C, H-4026 Debrecen (Hungary); Mascali, D.; Castro, G.; Caliri, C.; Gammino, S. [Instituto Nazionale di Fisica Nucleare—Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania (Italy); Romano, F. P. [Instituto Nazionale di Fisica Nucleare—Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania (Italy); CNR, Istituto per i Beni Archeologici e Monumentali, Via Biblioteca 4, 95124 Catania (Italy)

    2016-02-15

    Imaging of the electron cyclotron resonance (ECR) plasmas by using CCD camera in combination with a pinhole is a non-destructive diagnostics method to record the strongly inhomogeneous spatial density distribution of the X-ray emitted by the plasma and by the chamber walls. This method can provide information on the location of the collisions between warm electrons and multiple charged ions/atoms, opening the possibility to investigate the direct effect of the ion source tuning parameters to the plasma structure. The first successful experiment with a pinhole X-ray camera was carried out in the Atomki ECR Laboratory more than 10 years ago. The goal of that experiment was to make the first ECR X-ray photos and to carry out simple studies on the effect of some setting parameters (magnetic field, extraction, disc voltage, gas mixing, etc.). Recently, intensive efforts were taken to investigate now the effect of different RF resonant modes to the plasma structure. Comparing to the 2002 experiment, this campaign used wider instrumental stock: CCD camera with a lead pinhole was placed at the injection side allowing X-ray imaging and beam extraction simultaneously. Additionally, Silicon Drift Detector (SDD) and High Purity Germanium (HPGe) detectors were installed to characterize the volumetric X-ray emission rate caused by the warm and hot electron domains. In this paper, detailed comparison study on the two X-ray camera and detector setups and also on the technical and scientific goals of the experiments is presented.

  17. Self-organized criticality in X-ray flares of gamma-ray burst afterglows

    CERN Document Server

    Wang, F Y

    2013-01-01

    X-ray flares detected in nearly half of gamma-ray burst (GRB) afterglows are one of the most intriguing phenomena in high-energy astrophysics. All the observations indicate that the central engines of bursts, after the gamma-ray emission has ended, still have long periods of activity, during which energetic explosions eject relativistic materials, leading to late-time X-ray emission. It is thus expected that X-ray flares provide important clues to the nature of the central engines of GRBs, and more importantly, unveil the physical mechanism of the flares themselves, which has so far remained mysterious. Here we report statistical results of X-ray flares of GRBs with known redshifts, and show that X-ray flares and solar flares share three statistical properties: power-law frequency distributions for energies, durations, and waiting times. All of the distributions can be well understood within the physical framework of a self-organized criticality (SOC) system. The statistical properties of X-ray flares of GRBs...

  18. Hard X-Ray Burst Detected From Caltech Plasma Jet Experiment Magnetic Reconnection Event

    Science.gov (United States)

    Marshall, Ryan S.; Bellan, Paul M.

    2016-10-01

    In the Caltech plasma jet experiment a 100 kA MHD driven jet becomes kink unstable leading to a Rayleigh-Taylor instability that quickly causes a magnetic reconnection event. Movies show that the Rayleigh-Taylor instability is simultaneous with voltage spikes across the electrodes that provide the current that drives the jet. Hard x-rays between 4 keV and 9 keV have now been observed using an x-ray scintillator detector mounted just outside of a kapton window on the vacuum chamber. Preliminary results indicate that the timing of the x-ray burst coincides with a voltage spike on the electrodes occurring in association with the Rayleigh-Taylor event. The x-ray signal accompanies the voltage spike and Rayleigh-Taylor event in approximately 50% of the shots. A possible explanation for why the x-ray signal is sometimes missing is that the magnetic reconnection event may be localized to a specific region of the plasma outside the line of sight of the scintillator. The x-ray signal has also been seen accompanying the voltage spike when no Rayleigh-Taylor is observed. This may be due to the interframe timing on the camera being longer than the very short duration of the Rayleigh-Taylor instability.

  19. X-ray experiments for Space applications in intermediate energy range

    CERN Document Server

    Yadav, Vipin K; Nandi, Anuj; Palit, Sourav

    2009-01-01

    X-ray experiments in the intermediate energy range (1-50 keV) are carried out at the Indian Centre for Space Physics (ICSP), Kolkata for space application. The purpose is to carry out developmental studies of space instruments to observe energetic phenomena from compact objects (black hole and compact stars) and active stars and their testing and evaluation. The testing/evaluation setup primarily consists of an X-ray generator, various X-ray imaging masks, an X-ray imager (CMOS) and an X-ray spectrometer (Si-PIN photo-diode). The X-ray generator (Mo target) operates in 1-50 kV anode voltage, and 1-30 mA beam current. A 45 feet long shielded collimator is used to collimate the beam which leads to the detector chamber having a 30 arc-sec angular diameter. Two types of imaging masks are used - conventional Coded Aperture Masks (CAM) and Tungsten Fresnel half-period zone-plates (ZPs) having angular resolutions of a few tens of arc-sec. The Moire fringe pattern produced by the composite shadows of two ZPs is inver...

  20. X-ray pinhole camera setups used in the Atomki ECR Laboratory for plasma diagnostics

    Science.gov (United States)

    Rácz, R.; Biri, S.; Pálinkás, J.; Mascali, D.; Castro, G.; Caliri, C.; Romano, F. P.; Gammino, S.

    2016-02-01

    Imaging of the electron cyclotron resonance (ECR) plasmas by using CCD camera in combination with a pinhole is a non-destructive diagnostics method to record the strongly inhomogeneous spatial density distribution of the X-ray emitted by the plasma and by the chamber walls. This method can provide information on the location of the collisions between warm electrons and multiple charged ions/atoms, opening the possibility to investigate the direct effect of the ion source tuning parameters to the plasma structure. The first successful experiment with a pinhole X-ray camera was carried out in the Atomki ECR Laboratory more than 10 years ago. The goal of that experiment was to make the first ECR X-ray photos and to carry out simple studies on the effect of some setting parameters (magnetic field, extraction, disc voltage, gas mixing, etc.). Recently, intensive efforts were taken to investigate now the effect of different RF resonant modes to the plasma structure. Comparing to the 2002 experiment, this campaign used wider instrumental stock: CCD camera with a lead pinhole was placed at the injection side allowing X-ray imaging and beam extraction simultaneously. Additionally, Silicon Drift Detector (SDD) and High Purity Germanium (HPGe) detectors were installed to characterize the volumetric X-ray emission rate caused by the warm and hot electron domains. In this paper, detailed comparison study on the two X-ray camera and detector setups and also on the technical and scientific goals of the experiments is presented.

  1. X-ray Measurements of Black Hole X-ray Binary Source GRS 1915+105 and the Evolution of Hard X-ray Spectrum

    Indian Academy of Sciences (India)

    R. K. Manchanda

    2000-06-01

    We report the spectral measurement of GRS 1915+105 in the hard X-ray energy band of 20-140keV. The observations were made on March 30th, 1997 during a quiescent phase of the source. We discuss the mechanism of emission of hard X-ray photons and the evolution of the spectrum by comparing the data with earlier measurements and an axiomatic model for the X-ray source.

  2. X-Ray photoelectron Spectroscopy Applications

    Energy Technology Data Exchange (ETDEWEB)

    Engelhard, Mark H.; Droubay, Timothy C.; Du, Yingge

    2017-01-03

    With capability for obtaining quantitative elemental composition, chemical and electronic state, and overlayer thickness information from the top ~10 nm of a sample surface, X-ray Photoelectron Spectroscopy (XPS) or Electron Spectroscopy for Chemical Analysis (ESCA) is a versatile and widely used technique for analyzing surfaces. The technique is applied to a host of materials, from insulators to conductors in virtually every scientific field and sub-discipline. More recently, XPS has been extended under in-situ and operando conditions. Following a brief introduction to XPS principles and instrument components, this article exemplifies widely ranging XPS applications in material and life sciences.

  3. The X-ray Telescope of CAST

    OpenAIRE

    Kuster, M.; Bräuninger, H.; Cébrian, S.; Davenport, M.; Elefteriadis, C.; Englhauser, J.; Fischer, H.; Franz, J.; Friedrich, P.; R. Hartmann; Heinsius, F.H.; Hoffmann, D.H.H.; Hoffmeister, G.; Joux, J. N.; Kang, D.

    2007-01-01

    The Cern Axion Solar Telescope (CAST) is in operation and taking data since 2003. The main objective of the CAST experiment is to search for a hypothetical pseudoscalar boson, the axion, which might be produced in the core of the sun. The basic physics process CAST is based on is the time inverted Primakoff effect, by which an axion can be converted into a detectable photon in an external electromagnetic field. The resulting X-ray photons are expected to be thermally distributed between 1 and...

  4. Aviation security x-ray detection challenges

    Science.gov (United States)

    Harvey, T.

    2016-05-01

    In this paper, a review of the background and some drivers are provided for X-ray screening for aviation security. Some of the key considerations are highlighted along with impacts of the image-based approaches and signature approaches. The role of information theory is discussed along with some recent work that may influence the technical direction by posing the question: "what measurements, parameters and metrics should be considered in future system design?" A path forward should be based on information theory, however electronic machines will likely interface with humans and be dollar-cost driven, so ultimately solutions must consider additional parameters other than only technical performance factors.

  5. X-ray characterisation of nanostructured materials

    DEFF Research Database (Denmark)

    Oddershede, Jette

    austenite produced using a novel method showed that CrN formed even at temperatures below 450± where the mobility of Cr is very low. 3) Carbon nanotubes, a non-crystalline material with a periodic structure. It was shown that the mean bulk structural properties of the nanotubes can be obtained from XRPD...... of the experi- mental XRPD patterns, the need for new interpretation methods has arisen. The method described in the present thesis is by no means new, in fact it was developed by Debye in 1915. However, the Debye method it is rather computationally heavy, so in practise it is only applicable to the X-ray char...

  6. Elements of modern X-ray physics

    CERN Document Server

    Als-Nielsen, Jens

    2011-01-01

    Eagerly awaited, this second edition of a best-selling text comprehensively describes from a modern perspective the basics of x-ray physics as well as the completely new opportunities offered by synchrotron radiation. Written by internationally acclaimed authors, the style of the book is to develop the basic physical principles without obscuring them with excessive mathematics. The second edition differs substantially from the first edition, with over 30% new material, including: A new chapter on non-crystalline diffraction - designed to appeal to the large community wh

  7. Next-Generation X-Ray Astronomy

    Science.gov (United States)

    White, Nicholas E.

    2011-01-01

    The future timing capabilities in X-ray astronomy will be reviewed. This will include reviewing the missions in implementation: Astro-H, GEMS, SRG, and ASTROSAT; those under study: currently ATHENA and LOFT; and new technologies that may enable future missions e.g. Lobster eye optics. These missions and technologies will bring exciting new capabilities across the entire time spectrum from micro-seconds to years that e.g. will allow us to probe close to the event horizon of black holes and constrain the equation of state of neutron stars.

  8. The BMW X-ray Cluster Survey

    CERN Document Server

    Moretti, A; Campana, S; Covino, S; Lazzati, D; Longhetti, M; Molinari, E; Panzera, M R; Tagliaferri, G; Dell'Antonio, I P; Moretti, Alberto; Guzzo, Luigi; Campana, Sergio; Covino, Stefano; Lazzati, Davide; Longhetti, Marcella; Molinari, Emilio; Panzera, Maria Rosa; Tagliaferri, Gianpiero; Antonio, Ian Dell'

    2001-01-01

    We describe the main features of the BMW survey of serendipitous X-ray clusters, based on the still unexploited ROSAT-HRI archival observations. The sky coverage, surface density and first deep optical CCD images of the candidates indicate that this sample can represent an excellent complement to the existing PSPC deep cluster surveys and will provide us with a fully independent probe of the evolution of the cluster abundance, in addition to significantly increasing the number of clusters known at z>0.6.

  9. Laboratory for X-Ray Optics

    Science.gov (United States)

    1993-04-29

    Kearney, "El uso de las pelfculas delgadas en la optica de rayos - x ," Proc. Symposium on the Physics of Superlattices, May 1991, in press. 6. J.M...Bolling Air Force Base ELEMENT NO. NO. NO ACCESSION NO Washin ton, D.C. 20332- //( ~ ~ C 11. TITLE (Incluft Security Claw ffation) [ TLaboratory for X ...three years under contract AFOSR-90-O 140, "Laboratory for X -Ray O.ptics. Duig thspro we concenrae our effrt in two areas: 1) grwth of epitaxial

  10. The X-ray Polarimetry Explorer (XPE)

    Science.gov (United States)

    Ramsey, Brian

    2004-01-01

    We present details of a Thomson scattering polarimeter suitable for a small-explorer- class mission. Termed XPE, for X-Ray Polarimetry Explorer, the instrument consists of a beryllium scattering cone surrounded by an annular multiwire proportional counter which registers the energy and position of scattered source photons. The polarimeter is sensitive over an energy range of 7-27 keV and will achieve 3% minimum detectable polarization of Her X-1 in a 1/2-day observation, and cover a 30-target core observation program, at the same sensitivity level, in approximately 8 months.

  11. Glancing angle synchrotron X-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Cernik, R.J. [Daresbury Lab., Warrington, WA (United States)

    1996-09-01

    This paper describes in basic detail some of the techniques that can be used to study thin films and surfaces. These are all in the X-ray region and cover reflectivity, diffraction form polycrystalline films, textured films and single crystal films. Other effects such as fluorescence and diffuse scattering are mentioned but not discussed in detail. Two examples of the reflectivity from multilayers and the diffraction from iron oxide films are discussed. The advantages of the synchrotron for these studies is stressed and the experimental geometries that can be employed are described i detail. A brief bibliography is provided at the end to accompany this part of the 1996 Frascati school.

  12. X-ray optics for axion helioscopes

    DEFF Research Database (Denmark)

    Jakobsen, Anders Clemen; Pivovaroff, Michael J.; Christensen, Finn Erland

    2013-01-01

    A method of optimizing grazing incidence x-ray coatings in ground based axion helioscopes is presented. Software has been been developed to find the optimum coating when taking both axion spectrum and Micromegas detector quantum efficiency into account. A comparison of the relative effective area...... in the telescope using different multilayer material combinations is produced. Similar methods are used for IAXO, a planned axion helioscope. Additionally, the optimal focal length is modelled while taking into account the least possible background contribution from the detector. © (2013) COPYRIGHT Society...

  13. Wakefield Undulator For Generating X-rays

    CERN Document Server

    Opanasenko, A N

    2004-01-01

    Conception of wakefield undulator (WFU) with very short period is presented. In the base of photon generation by the WFU lies a new mechanism of undulator-type radiation emitted by an ultrarelativistic electron bunch that undulates due to non-synchronous spatial harmonics of its wakefields while the bunch moves along a periodic waveguide. The creation of the WFU with sub-millimeter periods due to advanced accelerator technology opens possibilities to generate hard X-rays employing relatively low electron energies without external alternative fields.

  14. Hard X-rays from NGC 4151: A thermal origin?

    Science.gov (United States)

    Titarchuk, Lev; Mastichiadis, Apostolos

    1994-01-01

    We present a model for explaining the recent combined X-ray and low-energy gamma-ray observations of the Seyfert galaxy NGC 4151. According to this model, soft photons become Comptonized in a hot spot producing simultaneously the low-energy power law as observed by Ginga and the high-energy cutoff observed by the Oriented Scintillation Spectrometer Experiment (OSSE). Implementing recently developed theoretical calculations toward a generalized theory of Comptonization, we were able to find fits to the observations using only two parameters which characterize the physical quantities of the emission region: the plasma cloud optical depth and its temperature. We find that there is no need for additional nonthermal, reflection, or higher temperature thermal components to fit the aforementioned OSSE and Ginga observations. We derive in addition the size of the photon region and the temperature of the upscattered soft photons. We should emphasize, also, that any attempt at fitting only the high-energy parts of the spectrum (photon energies greater than 60 keV) by the Sunyaev & Titarchuk (1980) nonrelativistic Comptonization model leads to an underestimate of the Comptonization parameter y (or, equivalently, to an overestimation of the X-ray power-law spectral slope) and leads, as a result, to incorrect proportions between the low-energy and high-energy parts of the spectrum.

  15. Femtosecond X-ray scattering in condensed matter

    Energy Technology Data Exchange (ETDEWEB)

    Korff Schmising, Clemens von

    2008-11-24

    This thesis investigates the manifold couplings between electronic and structural properties in crystalline Perovskite oxides and a polar molecular crystal. Ultrashort optical excitation changes the electronic structure and the dynamics of the connected reversible lattice rearrangement is imaged in real time by femtosecond X-ray scattering experiments. An epitaxially grown superlattice consisting of alternating nanolayers of metallic and ferromagnetic strontium ruthenate (SRO) and dielectric strontium titanate serves as a model system to study optically generated stress. In the ferromagnetic phase, phonon-mediated and magnetostrictive stress in SRO display similar sub-picosecond dynamics, similar strengths but opposite sign and different excitation spectra. The amplitude of the magnetic component follows the temperature dependent magnetization square, whereas the strength of phononic stress is determined by the amount of deposited energy only. The ultrafast, phonon-mediated stress in SRO compresses ferroelectric nanolayers of lead zirconate titanate in a further superlattice system. This change of tetragonal distortion of the ferroelectric layer reaches up to 2 percent within 1.5 picoseconds and couples to the ferroelectric soft mode, or ion displacement within the unit cell. As a result, the macroscopic polarization is reduced by up to 100 percent with a 500 femtosecond delay that is due to final elongation time of the two anharmonically coupled modes. Femtosecond photoexcitation of organic chromophores in a molecular, polar crystal induces strong changes of the electronic dipole moment via intramolecular charge transfer. Ultrafast changes of transmitted X-ray intensity evidence an angular rotation of molecules around excited dipoles following the 10 picosecond kinetics of the charge transfer reaction. Transient X-ray scattering is governed by solvation, masking changes of the chromophore's molecular structure. (orig.)

  16. Bone age assessment by dual-energy X-ray absorptiometry in children: An alternative for X-ray?

    NARCIS (Netherlands)

    D.H.M. Heppe (Denise); H.R. Taal (Rob); G.D.S. Ernst (Gesina); E.L.T. van den Akker (Erica); M.H. Lequin (Maarten); A.C.S. Hokken-Koelega (Anita); J.J.M. Geelhoed (Miranda); V.W.V. Jaddoe (Vincent)

    2012-01-01

    textabstractObjective: The aim of the study was to validate dual-energy X-ray absorptiometry (DXA) as a method to assess bone age in children. Methods: Paired dual-energy X-ray absorptiometry (DXA) scans and X-rays of the left hand were performed in 95 children who attended the paediatric endocrinol

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

    DEFF Research Database (Denmark)

    Rana, Vikram; Loh, Alan; Corbel, Stephane

    2016-01-01

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

  18. The color of X-rays: Spectral X-ray computed tomography using energy sensitive pixel detectors

    NARCIS (Netherlands)

    Schioppa, E.J.

    2014-01-01

    Energy sensitive X-ray imaging detectors are produced by connecting a semiconductor sensor to a spectroscopic pixel readout chip. In this thesis, the applicability of such detectors to X-ray Computed Tomography (CT) is studied. A prototype Medipix based silicon detector is calibrated using X-ray flu

  19. Calculation of x-ray scattering patterns from nanocrystals at high x-ray intensity

    OpenAIRE

    Malik Muhammad Abdullah; Zoltan Jurek; Sang-Kil Son; Robin Santra

    2016-01-01

    We present a generalized method to describe the x-ray scattering intensity of the Bragg spots in a diffraction pattern from nanocrystals exposed to intense x-ray pulses. Our method involves the subdivision of a crystal into smaller units. In order to calculate the dynamics within every unit we employ a Monte-Carlo (MC)-molecular dynamics (MD)-ab-initio hybrid framework using real space periodic boundary conditions. By combining all the units we simulate the diffraction pattern of a crystal la...

  20. Fundamentals of energy dispersive X-ray analysis

    CERN Document Server

    Russ, John C; Kiessling, R; Charles, J

    1984-01-01

    Fundamentals of Energy Dispersive X-ray Analysis provides an introduction to the fundamental principles of dispersive X-ray analysis. It presents descriptions, equations, and graphs to enable the users of these techniques to develop an intuitive and conceptual image of the physical processes involved in the generation and detection of X-rays. The book begins with a discussion of X-ray detection and measurement, which is accomplished by one of two types of X-ray spectrometer: energy dispersive or wavelength dispersive. The emphasis is on energy dispersive spectrometers, given their rather wid