WorldWideScience

Sample records for equatorial x-ray intensities

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

    Directory of Open Access Journals (Sweden)

    Malik Muhammad Abdullah

    2016-09-01

    Full Text Available 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-molecular dynamics-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.

  2. Compton spectra of atoms at high x-ray intensity

    Science.gov (United States)

    Son, Sang-Kil; Geffert, Otfried; Santra, Robin

    2017-03-01

    Compton scattering is the nonresonant inelastic scattering of an x-ray photon by an electron and has been used to probe the electron momentum distribution in gas-phase and condensed-matter samples. In the low x-ray intensity regime, Compton scattering from atoms dominantly comes from bound electrons in neutral atoms, neglecting contributions from bound electrons in ions and free (ionized) electrons. In contrast, in the high x-ray intensity regime, the sample experiences severe ionization via x-ray multiphoton multiple ionization dynamics. Thus, it becomes necessary to take into account all the contributions to the Compton scattering signal when atoms are exposed to high-intensity x-ray pulses provided by x-ray free-electron lasers (XFELs). In this paper, we investigate the Compton spectra of atoms at high x-ray intensity, using an extension of the integrated x-ray atomic physics toolkit, xatom. As the x-ray fluence increases, there is a significant contribution from ionized electrons to the Compton spectra, which gives rise to strong deviations from the Compton spectra of neutral atoms. The present study provides not only understanding of the fundamental XFEL-matter interaction but also crucial information for single-particle imaging experiments, where Compton scattering is no longer negligible. , which features invited work from the best early-career researchers working within the scope of J. Phys. B. This project is part of the Journal of Physics series’ 50th anniversary celebrations in 2017. Sang-Kil Son was selected by the Editorial Board of J. Phys. B as an Emerging Leader.

  3. Intense soft X-ray flux from Her-1

    Science.gov (United States)

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

    1976-01-01

    An intense flux of soft X-rays extending up to at least 1 keV has been observed from Her X-1. If the soft X-ray intensity is corrected for interstellar absorption the luminosity between 0.16 and 1 keV is comparable to that from 2-10 keV. The soft X-rays are modulated with the 1.24 sec period observed at higher energies but are approximately 180 deg out of phase with the high energy flux. These results extend the detection of this flux to higher energy, a different binary phase, and to a time 19 periods (of the 35 day cycle) later. These observations suggest that this soft emission is a stable feature in the spectrum of this source during its X-ray on state and that this emission is local to Her X-1.

  4. Intense picosecond x-rays from structured targets

    Science.gov (United States)

    Kulcsar, Gabor

    Laser plasmas from a new type of nanostructured surface are studied. This nanowire surface is especially useful as a very high absorption target for high power (1 TW) subpicosecond laser-matter interaction. The ensemble of oriented 10-200 nm metallic fibers of this material have linear absorption of 1 m m light greater than 95%. When irradiated by 1 ps pulses at intensities up to 1017 W/cm-2, these targets produce a pulse of x-rays (average energy > 1.5 keV) 30 times more efficiently than do uniform solid targets, while preserving several-picosecond emission times. X-ray conversion efficiencies from the nanowire target and from previously investigated grating and `smoke' targets are compared to those of flat targets for various angles of incidence and polarizations. Streak camera results show that a bright picosecond measure x-ray pulse is emitted from the near-solid density plasma created from the nanowire target. The measured x-ray pulse length is resolution-limited ( glass system is based on a feedback-controlled mode-locked oscillator capable of providing high contrast 1 ps pulses at a wavelength of 1.054 m m, with energies up to 5 m J/pulse. The characteristics of the CPA system are described. A new detector was developed to measure absolute x-ray yield, in various spectral ranges, radiated from the solid-density plasma. A calibrated silicon PIN photodiode connected to a charge-sensitive amplifier circuit allows x-ray yield measurements from picosecond pulses. If properly filtered the detector can measure the amount of x-rays radiated in a narrow spectral range. The electrical and spectral characteristics of the PIN photodiode detectors are given.

  5. X-ray investigations in intensive care units

    Energy Technology Data Exchange (ETDEWEB)

    Pokieser, H.

    1981-10-01

    From special care following surgery and from arteficial respiration of polio patients the modern and very special intensive medical care has developed. At the same time the provisional bedside radiology was improved to one branch of clinical radiology with special organisation and methods of investigation. Importance and urgency of radiological information are requiring close cooperation of all medical branches. Functions of these different groups have to be defined. The movable X-ray apparatus of 20 kV output is necessary for every intensive care unit. Hard beam technique for lung X-rays, scattered radiation grids and adequate positioning of the patient are important to get the same high quality pictures than from the radiological department.

  6. Towards phasing using high X-ray intensity

    Directory of Open Access Journals (Sweden)

    Lorenzo Galli

    2015-11-01

    Full Text Available X-ray free-electron lasers (XFELs show great promise for macromolecular structure determination from sub-micrometre-sized crystals, using the emerging method of serial femtosecond crystallography. The extreme brightness of the XFEL radiation can multiply ionize most, if not all, atoms in a protein, causing their scattering factors to change during the pulse, with a preferential `bleaching' of heavy atoms. This paper investigates the effects of electronic damage on experimental data collected from a Gd derivative of lysozyme microcrystals at different X-ray intensities, and the degree of ionization of Gd atoms is quantified from phased difference Fourier maps. A pattern sorting scheme is proposed to maximize the ionization contrast and the way in which the local electronic damage can be used for a new experimental phasing method is discussed.

  7. Performance of multilayers in intense synchrotron x-ray beams

    Energy Technology Data Exchange (ETDEWEB)

    Ziegler, E.; Lepetre, Y.; Joksch, S.; Saile, V.; Mourikis, S.; Viccaro, P. J.; Rolland, G.; Laugier, F.

    1989-07-01

    The use of multilayer reflectors under intense synchroton x-ray beams requires to develop a new generation of multilayered materials that can withstand a high-power load in excess of 100 W/mm/sup 2/. Multilayers with the high-/ital Z/ layer consisting either of a pure element or of compounds such as carbides, nitrides, or silicides have been produced. Because the fabrication conditions are not yet optimized, thin films with satisfactory layer were not obtained leading to poor reflectivities. Such multilayers have been both thermally annealed in a furnace and exposed to a synchrotron beam with a power density of about 1 W/mm/sup 2/. The resulting damage ranges from the total destruction of the layering to a reduction of the reflectivity by typically 40%--60%. In some cases an only 1%--15% loss in reflectivity has been observed.

  8. Compressive x-ray phase tomography based on the transport of intensity equation.

    Science.gov (United States)

    Tian, Lei; Petruccelli, Jonathan C; Miao, Qin; Kudrolli, Haris; Nagarkar, Vivek; Barbastathis, George

    2013-09-01

    We develop and implement a compressive reconstruction method for tomographic recovery of refractive index distribution for weakly attenuating objects in a microfocus x-ray system. This is achieved through the development of a discretized operator modeling both the transport of intensity equation and the x-ray transform that is suitable for iterative reconstruction techniques.

  9. Relationship between x-ray illumination field size and flat field intensity and its impacts on x-ray imaging.

    Science.gov (United States)

    Dong, Xue; Niu, Tianye; Jia, Xun; Zhu, Lei

    2012-10-01

    X-ray cone-beam CT (CBCT) is being increasingly used for various clinical applications, while its performance is still hindered by image artifacts. This work investigates a new source of reconstruction error, which is often overlooked in the current CBCT imaging. The authors find that the x-ray flat field intensity (I(0)) varies significantly as the illumination volume size changes at different collimator settings. A wrong I(0) value leads to inaccurate CT numbers of reconstructed images as well as wrong scatter measurements in the CBCT research. The authors argue that the finite size of x-ray focal spot together with the detector glare effect cause the I(0) variation at different illumination sizes. Although the focal spot of commercial x-ray tubes typically has a nominal size of less than 1 mm, the off-focal-spot radiation covers an area of several millimeters on the tungsten target. Due to the large magnification factor from the field collimator to the detector, the penumbra effects of the collimator blades result in different I(0) values for different illumination field sizes. Detector glare further increases the variation, since one pencil beam of incident x-ray is scattered into an area of several centimeters on the detector. In this paper, the authors study these two effects by measuring the focal spot distribution with a pinhole assembly and the detector point spread function (PSF) with an edge-spread function method. The authors then derive a formula to estimate the I(0) value for different illumination field sizes, using the measured focal spot distribution and the detector PSF. Phantom studies are carried out to investigate the accuracy of scatter measurements and CT images with and without considering the I(0) variation effects. On our tabletop system with a Varian Paxscan 4030CB flat-panel detector and a Varian RAD-94 x-ray tube as used on a clinical CBCT system, the focal spot distribution has a measured full-width-at-half-maximum (FWHM) of around 0

  10. Simulation of intense laser-dense matter interactions. X-ray production and laser absorption

    Energy Technology Data Exchange (ETDEWEB)

    Ueshima, Yutaka; Kishimoto, Yasuaki; Sasaki, Akira [Japan Atomic Energy Research Inst., Neyagawa, Osaka (Japan). Kansai Research Establishment; Sentoku, Yasuhiko; Tajima, Toshiki

    1998-03-01

    The development of short-pulse ultra high intensity lasers will enable us to generate short-pulse intense soft and hard X-rays. Acceleration of an electron in laser field generates intense illuminated located radiation, Larmor radiation, around KeV at 10{sup 18} W/cm{sup 2} with 100 TW and 1 {mu}m wave length laser. The Coulomb interaction between rest ions and relativistic electron generates broad energy radiation, bremsstrahlung emission, over MeV at 10{sup 18} W/cm{sup 2} with the same condition. These intense radiations come in short pulses of the same order as that of the irradiated laser. The generated intense X-rays, Larmor and bremsstrahlung radiation, can be applied to sources of short pulse X-ray, excitation source of inner-shell X-ray laser, position production and nuclear excitation, etc. (author)

  11. Development of X-Ray Sources Using Intense Laser Pulses and Their Applications to X-Ray Microscopy

    Science.gov (United States)

    Kim, H. T.; Lee, K. H.; Yun, H.; Kim, I. J.; Kim, C. M.; Pae, K. H.; Sung, J. H.; Lee, S. K.; Jeong, T. M.; Nam, C. H.

    We report the development of x-ray sources and their applications to x-ray microscopy. We applied a Ni-like Ag x-ray laser at 13.9 nm to Fourier transform holography (FTH) and obtained a reconstructed image with a resolution of 87 nm using a single-shot x-ray laser pulse. As the achievable spatial resolution of the single-shot FTH is limited by the strength of the reference wave, we enhanced the resolution of the x-ray imaging using the holography with extended reference by autocorrelation linear differential operation (HERALDO). Clear holograms could be recorded over the full size of an x-ray CCD, and the hologram reconstruction provided an image with a minimum resolution of 24 nm, close to the diffraction limited resolution of the imaging system.

  12. Two electron response to an intense x-ray free electron laser pulse

    Energy Technology Data Exchange (ETDEWEB)

    Moore, L R; Parker, J S; Meharg, K J; Armstrong, G S J; Taylor, K T, E-mail: l.moore@qub.ac.u [DAMTP, David Bates Building, Queen' s University Belfast, Belfast, BT7 1NN (United Kingdom)

    2009-11-01

    New x-ray free electron lasers (FELs) promise an ultra-fast ultra-intense regime in which new physical phenomena, such as double core hole formation in at atom, should become directly observable. Ahead of x-ray FEL experiments, an initial key task is to theoretically explore such fundamental laser-atom interactions and processes. To study the response of a two-electron positive ion to an intense x-ray FEL pulse, our theoretical approach is a direct numerical integration, incorporating non-dipole Hamiltonian terms, of the full six-dimensional time-dependent Schroedinger equation. We present probabilities of double K-shell ionization in the two-electron positive ions Ne{sup 8+} and Ar{sup 16+} exposed to x-ray FEL pulses with frequencies in the range 50 au to 300 au and intensities in the range 10{sup 17} to 10{sup 22} W/cm{sup 2}.

  13. ANALYSIS AND MITIGATION OF X-RAY HAZARD GENERATED FROM HIGH INTENSITY LASER-TARGET INTERACTIONS

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, R.; Liu, J.C.; Prinz, A.A.; Rokni, S.H.; Woods, M.; Xia, Z.; /SLAC

    2011-03-21

    Interaction of a high intensity laser with matter may generate an ionizing radiation hazard. Very limited studies have been made, however, on the laser-induced radiation protection issue. This work reviews available literature on the physics and characteristics of laser-induced X-ray hazards. Important aspects include the laser-to-electron energy conversion efficiency, electron angular distribution, electron energy spectrum and effective temperature, and bremsstrahlung production of X-rays in the target. The possible X-ray dose rates for several femtosecond Ti:sapphire laser systems used at SLAC, including the short pulse laser system for the Matter in Extreme Conditions Instrument (peak power 4 TW and peak intensity 2.4 x 10{sup 18} W/cm{sup 2}) were analysed. A graded approach to mitigate the laser-induced X-ray hazard with a combination of engineered and administrative controls is also proposed.

  14. Radiation exposure during chest X-ray examinations in a premature intensive care unit: phantom studies

    Energy Technology Data Exchange (ETDEWEB)

    Duetting, T.; Foerste, B.; Darge, K.; Troeger, J. [Heidelberg Univ. (Germany). Dept. of Paediatric Radiology; Knoch, T. [Heidelberg Univ. (Germany). Central Radiation Protection

    1999-03-01

    Background. There are few reports on the radiation dose received by infants, their family and radiographers exposed to scatter radiation in a premature baby intensive care unit. Objective. To evaluate the degree of radiation exposure from diagnostic X-ray examinations with mobile X-ray machines in a premature intensive care unit. Materials and methods. The radiation exposure of an adjacent newborn, the radiographer and other persons in the room was simulated using phantoms during X-ray examination of the chest using vertical and horizontal beams. Results. Most of the measured doses were below the registration limit of the measuring apparatus and had to be extrapolated by multiple exposures. Without exception, the maximal doses were significantly lower than the permitted limit for persons not professionally exposed to X-rays. Conclusions. Recommendations to avoid unnecessary radiation exposure are given. (orig.) With 2 figs., 3 tabs., 10 refs.

  15. Direct intensity calibration of X-ray grazing-incidence microscopes with home-lab source

    Science.gov (United States)

    Li, Yaran; Xie, Qing; Chen, Zhiqiang; Xin, Qiuqi; Wang, Xin; Mu, Baozhong; Wang, Zhanshan; Liu, Shenye; Ding, Yongkun

    2018-01-01

    Direct intensity calibration of X-ray grazing-incidence microscopes is urgently needed in quantitative studies of X-ray emission from laser plasma sources in inertial confinement fusion. The existing calibration methods for single reflecting mirrors, crystals, gratings, filters, and X-ray detectors are not applicable for such X-ray microscopes due to the specific optical structure and the restrictions of object-image relation. This article presents a reliable and efficient method that can be performed using a divergent X-ray source and an energy dispersive Si-PIN (silicon positive-intrinsic-negative) detector in an ordinary X-ray laboratory. The transmission theory of X-ray flux in imaging diagnostics is introduced, and the quantities to be measured are defined. The calibration method is verified by a W/Si multilayer-coated Kirkpatrick-Baez microscope with a field of view of ˜95 μm at 17.48 keV. The mirror reflectance curve in the 1D coordinate is drawn with a peak value of 20.9% and an uncertainty of ˜6.0%.

  16. Calculated X-ray Intensities Using Monte Carlo Algorithms: A Comparison to Experimental EPMA Data

    Science.gov (United States)

    Carpenter, P. K.

    2005-01-01

    Monte Carlo (MC) modeling has been used extensively to simulate electron scattering and x-ray emission from complex geometries. Here are presented comparisons between MC results and experimental electron-probe microanalysis (EPMA) measurements as well as phi(rhoz) correction algorithms. Experimental EPMA measurements made on NIST SRM 481 (AgAu) and 482 (CuAu) alloys, at a range of accelerating potential and instrument take-off angles, represent a formal microanalysis data set that has been widely used to develop phi(rhoz) correction algorithms. X-ray intensity data produced by MC simulations represents an independent test of both experimental and phi(rhoz) correction algorithms. The alpha-factor method has previously been used to evaluate systematic errors in the analysis of semiconductor and silicate minerals, and is used here to compare the accuracy of experimental and MC-calculated x-ray data. X-ray intensities calculated by MC are used to generate a-factors using the certificated compositions in the CuAu binary relative to pure Cu and Au standards. MC simulations are obtained using the NIST, WinCasino, and WinXray algorithms; derived x-ray intensities have a built-in atomic number correction, and are further corrected for absorption and characteristic fluorescence using the PAP phi(rhoz) correction algorithm. The Penelope code additionally simulates both characteristic and continuum x-ray fluorescence and thus requires no further correction for use in calculating alpha-factors.

  17. Femtosecond response of polyatomic molecules to ultra-intense hard X-rays

    Science.gov (United States)

    Rudenko, A.; Inhester, L.; Hanasaki, K.; Li, X.; Robatjazi, S. J.; Erk, B.; Boll, R.; Toyota, K.; Hao, Y.; Vendrell, O.; Bomme, C.; Savelyev, E.; Rudek, B.; Foucar, L.; Southworth, S. H.; Lehmann, C. S.; Kraessig, B.; Marchenko, T.; Simon, M.; Ueda, K.; Ferguson, K. R.; Bucher, M.; Gorkhover, T.; Carron, S.; Alonso-Mori, R.; Koglin, J. E.; Correa, J.; Williams, G. J.; Boutet, S.; Young, L.; Bostedt, C.; Son, S.-K.; Santra, R.; Rolles, D.

    2017-06-01

    X-ray free-electron lasers enable the investigation of the structure and dynamics of diverse systems, including atoms, molecules, nanocrystals and single bioparticles, under extreme conditions. Many imaging applications that target biological systems and complex materials use hard X-ray pulses with extremely high peak intensities (exceeding 1020 watts per square centimetre). However, fundamental investigations have focused mainly on the individual response of atoms and small molecules using soft X-rays with much lower intensities. Studies with intense X-ray pulses have shown that irradiated atoms reach a very high degree of ionization, owing to multiphoton absorption, which in a heteronuclear molecular system occurs predominantly locally on a heavy atom (provided that the absorption cross-section of the heavy atom is considerably larger than those of its neighbours) and is followed by efficient redistribution of the induced charge. In serial femtosecond crystallography of biological objects—an application of X-ray free-electron lasers that greatly enhances our ability to determine protein structure—the ionization of heavy atoms increases the local radiation damage that is seen in the diffraction patterns of these objects and has been suggested as a way of phasing the diffraction data. On the basis of experiments using either soft or less-intense hard X-rays, it is thought that the induced charge and associated radiation damage of atoms in polyatomic molecules can be inferred from the charge that is induced in an isolated atom under otherwise comparable irradiation conditions. Here we show that the femtosecond response of small polyatomic molecules that contain one heavy atom to ultra-intense (with intensities approaching 1020 watts per square centimetre), hard (with photon energies of 8.3 kiloelectronvolts) X-ray pulses is qualitatively different: our experimental and modelling results establish that, under these conditions, the ionization of a molecule is

  18. Influence of X-ray tube spectral distribution on uncertainty of calculated fluorescent radiation intensity

    Energy Technology Data Exchange (ETDEWEB)

    Sitko, Rafal [Institute of Chemistry, Silesian University, 40-006 Katowice (Poland)], E-mail: rafal.sitko@us.edu.pl

    2007-08-15

    The relative radiation intensity (R{sub i}) defined as fluorescent radiation intensity of analyte in specimen to fluorescent radiation intensity of pure element or compound, e.g., oxide is used in calculation in both fundamental parameter methods and in theoretical influence coefficient algorithms. Accuracy of calculated R{sub i} is determined by uncertainties of atomic parameters, spectrometer geometry and also by X-ray tube spectral distribution. This paper presents the differences between R{sub i} calculated using experimental and theoretical X-ray tube spectra evaluated by three different algorithms proposed by Pella et al., Ebel, and Finkelshtein-Pavlova. The calculations are performed for the most common targets, i.e., Cr, Mo, Rh and W. In this study, R{sub i} is calculated for V, Cr, Mn, Fe, Co, Ni, Cu and Mo in steels as an example. The differences between R{sub i} calculated using different X-ray tube spectrum algorithms are presented when pure element standard, multielement standard similar to the analyzed material and one pure element standard for all analytes is used in X-ray fluorescence analysis. The differences between R{sub i} for intermediate-thickness samples (and also for thin films) and for X-ray tube, which ran for many hours, are also evaluated.

  19. Development of a compact beam intensity monitor for micro X-ray absorption fine structure measurements

    CERN Document Server

    Hayakawa, S; Oshima, M; Hirokawa, T

    2001-01-01

    A compact beam intensity monitor detecting an X-ray excited sample current from a thin metal foil was developed for micro X-ray absorption fine structure (XAFS) measurements. By utilizing gas amplification caused by the ejected photoelectrons or Auger electrons, the monitor can achieve better sensitivity than what can be realized with the ionization chamber. Fluctuation of the beam intensity through the pinhole of 10 mu m was precisely measured by using this monitor, and the XAFS spectrum from a Ni thin foil was successfully measured with adequate normalization.

  20. X-ray diagnosis of pneumothorax in intensive care units

    Energy Technology Data Exchange (ETDEWEB)

    Galanski, M.; Hartenauer, U.; Krumme, B.

    1981-10-01

    Pneumothorax is the most severe manifestation of pulmonary barotrauma which occurs in mechanical ventilation. Diagnosis of pneumothorax in intensive care radiology is of particular difficulty. Chest radiographs in supine position show a variety of signs which may be helpful but are not conclusive. There are different techniques for verification of ventrally located pneumothorax. 45/sup 0/ tangential radiographs of the hemithorax in question are most conclusive for demonstration of extrapulmonary air located inside the pleural cavity. This 45/sup 0/ technique is easy to carry out without changing the patients position.

  1. Ultrafast unequilibrium electron dynamics of aluminium interacting with an ultra-intense x-ray pulse

    Science.gov (United States)

    Gao, Cheng; Zeng, Jiaolong; Yuan, Jianmin

    2017-10-01

    Ultrafast nonequilibrium dynamics of free electrons in an ultra-intense and ultrafast x-ray pulse interacting with a solid-density aluminium is investigated by solving Fokker-Planck equation. X-ray propagation through aluminium is determined by solving a one-dimensional radiative transfer equation which is coupled with a time-dependent rate equation. Although high energy electrons are evidently nonequilibrium, they account for a small population fraction in the total free electrons. The transmission of an ultra-intense x-ray pulse through a 1 um thick solid-density aluminium sample is calculated and compared with a recent experiment, where good agreement is found and saturable absorption is evidently observed.

  2. Turning solid aluminium transparent by intense soft X-ray photoionization

    NARCIS (Netherlands)

    Nagler, B.; Zastrau, U.; Faustlin, R. R.; Vinko, S. M.; Whitcher, T.; Nelson, A. J.; Sobierajski, R.; Krzywinski, J.; Chalupsky, J.; Abreu, E.; Bajt, S.; Bornath, T.; Burian, T.; Chapman, H.; Cihelka, J.; Doppner, T.; Duesterer, S.; Dzelzainis, T.; Fajardo, M.; Forster, E.; Fortmann, C.; Galtier, E.; Glenzer, S. H.; Gode, S.; Gregori, G.; Hajkova, V.; Heimann, P.; Juha, L.; Jurek, M.; Khattak, F. Y.; Khorsand, A. R.; Klinger, D.; Kozlova, M.; Laarmann, T.; Lee, H. J.; Lee, R. W.; Meiwes-Broer, K. H.; Mercere, P.; Murphy, W. J.; Przystawik, A.; Redmer, R.; Reinholz, H.; Riley, D.; Ropke, G.; Rosmej, F.; Saksl, K.; Schott, R.; Thiele, R.; Tiggesbaumker, J.; Toleikis, S.; Tschentscher, T.; Uschmann, I.; Vollmer, H. J.; Wark, J. S.

    2009-01-01

    Saturable absorption is a phenomenon readily seen in the optical and infrared wavelengths. It has never been observed in core-electron transitions owing to the short lifetime of the excited states involved and the high intensities of the soft X-rays needed. We report saturable absorption of an

  3. Generation of intense soft X-rays from capillary discharge plasmas

    Indian Academy of Sciences (India)

    At Laser Plasma Division, RRCAT, a program on high voltage capillary discharge had been started. The system consists of a 400 kV Marx bank, water line capacitor, spark gap and capillary chamber. The initial results of the emission of intense short soft X-ray pulses (5–10 ns) from the capillary discharge are reported.

  4. A two-stage series diode for intense large-area moderate pulsed X rays production.

    Science.gov (United States)

    Lai, Dingguo; Qiu, Mengtong; Xu, Qifu; Su, Zhaofeng; Li, Mo; Ren, Shuqing; Huang, Zhongliang

    2017-01-01

    This paper presents a method for moderate pulsed X rays produced by a series diode, which can be driven by high voltage pulse to generate intense large-area uniform sub-100-keV X rays. A two stage series diode was designed for Flash-II accelerator and experimentally investigated. A compact support system of floating converter/cathode was invented, the extra cathode is floating electrically and mechanically, by withdrawing three support pins several milliseconds before a diode electrical pulse. A double ring cathode was developed to improve the surface electric field and emission stability. The cathode radii and diode separation gap were optimized to enhance the uniformity of X rays and coincidence of the two diode voltages based on the simulation and theoretical calculation. The experimental results show that the two stage series diode can work stably under 700 kV and 300 kA, the average energy of X rays is 86 keV, and the dose is about 296 rad(Si) over 615 cm(2) area with uniformity 2:1 at 5 cm from the last converter. Compared with the single diode, the average X rays' energy reduces from 132 keV to 88 keV, and the proportion of sub-100-keV photons increases from 39% to 69%.

  5. Neonatal doses from X ray examinations by birth weight in a neonatal intensive care unit

    Energy Technology Data Exchange (ETDEWEB)

    Ono, K.; Akahane, K.; Aota, T.; Hada, M.; Takano, Y.; Kai, M.; Kusama, T

    2003-07-01

    The aim of this study was to investigate the frequency and type of X ray examinations performed on neonates classified according to their birth weight in a neonatal intensive care unit (NICU). In this study, the radiology records of 2408 neonates who were admitted to the NICU of Oita Prefectural Hospital between January 1994 and September 1999 were investigated. This study revealed that the neonates with earlier gestational ages and lower birth weights required longer NICU stays and more frequent X ray examinations made using a mobile X ray unit. The average number of X ray examinations performed on neonates of less than 750 g birth weight was 26 films per neonate. In regard to computed tomography and fluoroscopy, no significant relationship was found between the birth weight and number of X rays. This study revealed that the entrance-surface dose per neonate was dependent upon the birth weight, while the maximum dose was not dependent upon the birth weight. The average neonatal dose in the NICU was predominantly from computed tomography and fluoroscopy. The individual dose varied widely among neonates. (author)

  6. Spectroscopic study of site selective DNA damage induced by intense soft X-rays

    CERN Document Server

    Fujii, K

    2003-01-01

    To investigate the mechanisms of DNA damage induced by direct photon impact, we observed the near edge X-ray absorption fine structures (NEXAFS) of DNA nucleobases using monochromatic synchrotron soft X-rays around nitrogen and oxygen K-shell excitation regions. Each spectrum obtained has unique structure corresponding to pi* excitation of oxygen or nitrogen 1s electron. These aspects open a way of nucleobase-selective photo-excitation in a DNA molecule using high resolution monochromatized soft X-rays. From the analysis of polarization-dependent intensities of the pi* resonance peak, it is clarified that adenine, guanine an uracil form orientated surface structure. Furthermore from the direct measurement of positive ions desorbed from photon irradiated DNA components, it is revealed that the sugar moiety is a fragile site in a DNA molecule. (author)

  7. Increase in the Reflected Intensity of X-Ray Films Using Photonic Crystals

    Science.gov (United States)

    Aly, Arafa H.; Eissa, M. F.

    Photographic film is the familiar image of recording X-ray method. Examinations performed with radiographic intensifying screens reduce the patient’s exposure to radiation of X-rays compared with those without radiographic intensifying screens, where it directs less than half of the light emitted from the X-ray film with a screen interaction. A reflective layer made of magnesium oxide or titanium dioxide is located between the screen and the base of the film; this layer can help regain the control of the header light in other directions and is forwarded to the film. One-dimensional array of photonic crystals (PCs) consists of MgO with Al and TiO2 with Al used as reflectors. This array may increase the reflected intensity by an amount of 10.88% if MgO-Al PCs with periodicity N=1 are used as reflectors.

  8. New mobile X-ray generator for the application in the intensive care department

    Energy Technology Data Exchange (ETDEWEB)

    Lutz, K.; Murmann, J.; Wetzel, G.

    1982-01-01

    This report introduces a new, mobile radiologic unit, the MOBILETT which has been used in the X-ray department of the Chirurgische Universitaetsklinik at Erlangen since November 1981. This system is a compact, highly mobile X-ray unit whose technical specifications (high-frequency generator with a performance of up to 30 kW, high input power of up to 400 mA and shortest exposure time down from 3 ms with a total weight of only 230 kg) show that this instrument has been designed particularly for the application in intensive care departments. The study reports about the application of this system in the intensive care department, about its handling and operation as well as its adaptation to any intensive care patient.

  9. Origin-independent calculation of quadrupole intensities in X-ray spectroscopy

    CERN Document Server

    Bernadotte, Stephan; Jacob, Christoph R

    2012-01-01

    For electronic excitations in the ultraviolet and visible range of the electromagnetic spectrum, the intensities are usually calculated within the dipole approximation, which assumes that the oscillating electric field is constant over the whole molecule. For the short wavelengths used in X-ray spectroscopy, this dipole approximation breaks down and it becomes necessary to include higher-order contributions. In quantum-chemical approaches to X-ray spectroscopy, these so-called quadrupole intensities have so far been calculated by including contributions depending on the square of the electric-quadrupole and magnetic-dipole transition moments. However, the resulting quadrupole intensities depend on the choice of the origin of the coordinate system. Here, we show that for obtaining an origin-independent theory, one has to include all contributions that are of the same order in the wave vector consistently. This leads to two additional contributions depending on products of the electric-dipole and electric-octup...

  10. The effect of ionizing photons (VUV + soft X-rays) in the equatorial and polar surfaces of the Europa moon

    Science.gov (United States)

    Pilling, Sergio; Alexandre Souza Bergantini, M.

    Europa is the sixth-closest moon of the planet Jupiter, and the smallest of the four Galilean satellites, but still the sixth-largest moon in the Solar System being only slightly smaller than Earth's Moon. Its cold surface is covered mainly by water ice and a small fraction of other molecular frozen species such as CO _{2}, NH _{3}, and SO _{2}. Since Europa has only a very thin O _{2} rich atmosphere, the surface is constantly exposed to space ionizing agents such as UV and soft X-rays photons, electrons and ions. In this work we investigate the effects produced by vacuum ultraviolet (VUV) and soft X-rays (and possibly secondary electrons) on the surface of Europa Moon, simulating this way the space weathering and the prebiotic photochemistry induced by solar photons on this moon. The experiments have been performed using a high vacuum portable chamber from the Laboratorio de Astroquimica e Astrobiologia (LASA/UNIVAP) coupled to the spherical grating monochromator (SGM) beamline in the Brazilian Synchrotron Light Source (LNLS) at Campinas, Brazil. The beamline was operated in off-focus and white beam mode, which produces a wide band spectral range of photons, mainly from 6 eV up to 1200 eV, with the total average flux at the sample of about 1x10 (14) photons cm (-2) s (-1) . The experiments simulate roughly 10.7 years of solar irradiation (energy delivered) on the Europa surface. In-situ sample analyses were performed by a Fourier transform infrared spectrometer. The samples were produced by the adsorption of a gaseous mixture containing H _{2}O:CO _{2}:NH _{3}:SO _{2} (10:1:1:1) at very low temperature (12 K) and than were slowly heated (2 K/min) to the temperatures in which the irradiation occur, i.e. at 90K and 50K, simulating this way the equatorial and polar regions of the moon. This scenario simulates the cold molecular delivery from comets in the early phases of this Jupiter’s moon. The infrared spectra of irradiated samples have presented the formation

  11. L X-ray energy shifts and intensity ratios in tantalum with C and N ions

    Indian Academy of Sciences (India)

    Abstract. The energy shifts and intensity ratios of different L X-ray components in tantalum el- ement due to 10 MeV carbon and 12 MeV nitrogen ions are estimated. From the observed energy shifts, the possible number of simultaneous vacancies in M shell are estimated. A comparison of. Lα/Lβ2 15. , Lβ1. /Lγ1 and Lγ2 ...

  12. L X-ray energy shifts and intensity ratios in tantalum with C and N ...

    Indian Academy of Sciences (India)

    The energy shifts and intensity ratios of different L X-ray components in tantalum element due to 10 MeV carbon and 12 MeV nitrogen ions are estimated. From the observed energy shifts, the possible number of simultaneous vacancies in M shell are estimated. A comparison of L/L 2,15, L 1/L 1 and L 2,3/L 4,4 with ...

  13. Aerogel Cherenkov detector for characterizing the intense flash x-ray source, Cygnus, spectrum

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Y., E-mail: yhkim@lanl.gov; Herrmann, H. W.; McEvoy, A. M.; Young, C. S.; Hamilton, C. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Schwellenbach, D. D.; Malone, R. M.; Kaufman, M. I.; Smith, A. S. [National Security Technologies, LLC, Los Alamos, New Mexico 87544 (United States)

    2016-11-15

    An aerogel Cherenkov detector is proposed to measure the X-ray energy spectrum from the Cygnus—intense flash X-ray source operated at the Nevada National Security Site. An array of aerogels set at a variety of thresholds between 1 and 3 MeV will be adequate to map out the bremsstrahlung X-ray production of the Cygnus, where the maximum energy of the spectrum is normally around 2.5 MeV. In addition to the Cherenkov radiation from aerogels, one possible competing light-production mechanism is optical transition radiation (OTR), which may be significant in aerogels due to the large number of transitions from SiO{sub 2} clusters to vacuum voids. To examine whether OTR is a problem, four aerogel samples were tested using a mono-energetic electron beam (varied in the range of 1–3 MeV) at NSTec Los Alamos Operations. It was demonstrated that aerogels can be used as a Cherenkov medium, where the rate of the light production is about two orders magnitude higher when the electron beam energy is above threshold.

  14. Mapping the continuous reciprocal space intensity distribution of X-ray serial crystallography.

    Science.gov (United States)

    Yefanov, Oleksandr; Gati, Cornelius; Bourenkov, Gleb; Kirian, Richard A; White, Thomas A; Spence, John C H; Chapman, Henry N; Barty, Anton

    2014-07-17

    Serial crystallography using X-ray free-electron lasers enables the collection of tens of thousands of measurements from an equal number of individual crystals, each of which can be smaller than 1 µm in size. This manuscript describes an alternative way of handling diffraction data recorded by serial femtosecond crystallography, by mapping the diffracted intensities into three-dimensional reciprocal space rather than integrating each image in two dimensions as in the classical approach. We call this procedure 'three-dimensional merging'. This procedure retains information about asymmetry in Bragg peaks and diffracted intensities between Bragg spots. This intensity distribution can be used to extract reflection intensities for structure determination and opens up novel avenues for post-refinement, while observed intensity between Bragg peaks and peak asymmetry are of potential use in novel direct phasing strategies.

  15. Size-dependent ultrafast ionization dynamics of nanoscale samples in intense femtosecond x-ray free-electron-laser pulses.

    Science.gov (United States)

    Schorb, Sebastian; Rupp, Daniela; Swiggers, Michelle L; Coffee, Ryan N; Messerschmidt, Marc; Williams, Garth; Bozek, John D; Wada, Shin-Ichi; Kornilov, Oleg; Möller, Thomas; Bostedt, Christoph

    2012-06-08

    All matter exposed to intense femtosecond x-ray pulses from the Linac Coherent Light Source free-electron laser is strongly ionized on time scales competing with the inner-shell vacancy lifetimes. We show that for nanoscale objects the environment, i.e., nanoparticle size, is an important parameter for the time-dependent ionization dynamics. The Auger lifetimes of large Ar clusters are found to be increased compared to small clusters and isolated atoms, due to delocalization of the valence electrons in the x-ray-induced nanoplasma. As a consequence, large nanometer-sized samples absorb intense femtosecond x-ray pulses less efficiently than small ones.

  16. Development of a software for reconstruction of X-ray fluorescence intensity maps

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Andre Pereira de; Braz, Delson; Mota, Carla Lemos, E-mail: apalmeid@gmail.co, E-mail: delson@lin.ufrj.b, E-mail: clemos@con.ufrj.b [Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear; Oliveira, Luis Fernando de; Barroso, Regina Cely; Pinto, Nivia Graciele Villela, E-mail: cely@uerj.b, E-mail: lfolive@uerj.b, E-mail: nitatag@gmail.co [Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ (Brazil). Inst. de Fisica; Cardoso, Simone Coutinho, E-mail: simone@if.ufrj.b [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Fisica; Moreira, Silvana, E-mail: silvana@fec.unicamp.b [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Faculdade de Engenharia Civil, Arquitetura e Urbanismo

    2009-07-01

    The technique of X-ray fluorescence (XRF) using SR microbeams is a powerful analysis tool for studying elemental composition in several samples. One application of this technique is the analysis done through the mapping of chemical elements forming a matrix of data. The aim of this work is the presentation of the program MapXRF, an in-house software designed to optimize the processing and mapping of fluorescence intensities data. This program uses spectra generated by QXAS as input data and separates the intensities of each chemical element found in the fluorescence spectra in files themselves. From these files, the program generates the intensity maps that can be visualized in any program of treatment of images. The proposed software was tested using fluorescence data obtained in the XRF beamline of XRF at Synchrotron Light National Laboratory (LNLS), Brazil. Automatic 2D scans were performed and element distribution maps were obtained in the form of a matrix of data. (author)

  17. X-ray emission simulation from hollow atoms produced by high intensity laser irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Moribayashi, Kengo; Sasaki, Akira; Zhidkov, A. [Japan Atomic Energy Research Inst., Kansai Research Establishment, Neyagawa, Osaka (Japan); Suto, Keiko [Nara Women' s Univ., Graduate School of Human Culture, Nara (Japan); Kagawa, Takashi [Nara Women' s Univ., Department of Physics, Nara (Japan)

    2001-10-01

    We theoretically study the x-ray emission from hollow atoms produced by collisions of multiply charged ions accelerated by a short pulse laser with a solid or foil. By using the multistep-capture-and-loss (MSCL) model a high conversion efficiency to x-rays in an ultrafast atomic process is obtained. It is also proposed to apply this x-ray emission process to the x-ray source. For a few keV x-rays this x-ray source has a clear advantage. The number of x-ray photons increases as the laser energy becomes larger. For a laser energy of 10 J, the number of x-ray photons of 3x10{sup 11} is estimated. (author)

  18. Measurements of output intensities at cone tip using six dental x-ray generators

    Energy Technology Data Exchange (ETDEWEB)

    Hayakawa, Yoshihiko; Kobayashi, Norio; Kousuge, Yuji; Fujimori, Hisao; Kuroyanagi, Kinya [Tokyo Dental Coll., Chiba (Japan)

    1997-06-01

    Output intensities (air-absorbed doses in air: Gy) were measured at the cone tip using six dental x-ray generators. The type 660 ionizing dosimeter (Victoreen, Inc.) was used. The flat probe, type 660-3, was set at the cone tip of each dental x-ray generator. Measurements at three exposure times, of approx. 0.3, 0.6 and 1.0 s were repeated five times. The exposure time versus air-absorbed dose relationship and the air-absorbed dose rate, were obtained for each generator. The number of exposure time settings required to give an air-absorbed dose of less than 2.00 mGy at the cone tip was evaluated for each generator. Outputs of two generators which were furnished with a short cone (20 cm focal spot to cone tip distance) were 3.38 and 6.95 mGy/sec at 60 kV, and 4.67 and 9.82 mGy/sec at 70 kV. Outputs of four generators with a long cone (30-35 cm) were distributed in the range of either 1.50-1.68 mGy/sec or 3.06-3.57 mGy/sec at 60 kV, and either 1.95-2.29 or 4.06-4.73 mGy/sec at 70 kV, respectively. The calculated outputs at 10 cm beyond the cone tip with two generators with a short cone were included in this range. The number of exposure time settings to give absorbed doses of less than 2.00 mGy was in the range of 43 to 70% for five generators. One of the six generators had the low output rate. This experiment using six dental generators clarified that there were two kinds of generators which were distinguished by the x-ray output intensity. Some dental x-ray generators had outputs in the range of approximately 1.5-1.7 mGy/sec at 60 kV, and approx. 2.0-2.3 mGy/sec at 70 kV at the tip of the long cone. Outputs with other generators were approximately twice of these values. These findings are useful to evaluate the doses absorbed by the patient`s skin surface, which is the maximum for the patient at the intraoral radiographic examination. (author)

  19. Laser-driven proton sources and their applications: femtosecond intense laser plasma driven simultaneous proton and x-ray imaging

    Energy Technology Data Exchange (ETDEWEB)

    Nishiuchi, M; Daido, H; Yogo, A; Sagisaka, A; Ogura, K; Orimo, S; Mori, M; Ma, J; Pirozhkov, A S; Kiriyama, H; Kanazawa, S; Kondo, S; Yamamoto, Y; Shimoura, T; Tanoue, M; Nakai, Y; Akutsu, A; Nagashima, A; Bulanov, S V; Esirkepov, T Z [Advanced Photon Research Center, JAEA, Kizugawa-shi, Kyoto (Japan)], E-mail: nishiuchi.mamiko@jaea.go.jp (and others)

    2008-05-01

    We have performed simultaneous proton and X-ray imaging with an ultra-short and high-intensity Ti: Sap laser system. More than 10{sup 10} protons, whose maximum energy reaches 2.5 MeV, were delivered within a {approx}ps bunch. At the same time, keV X-ray is generated at almost the same place where protons are emitted. We have performed the simultaneous imaging of the copper mesh by using proton and x-ray beams, in practical use of the characteristics of the laser produced plasma that it can provide those beams simultaneously without any serious problems on synchronization.

  20. Generation of hard X-ray from solid target irradiated by UV high intensity ultrashort pulse laser

    CERN Document Server

    Tao Ye; Tang Xiu Zhang; Shan Yu Sheng; Wang Nai Yan

    2002-01-01

    Hard X-ray continuum generated from interaction of UV high intensity ultrashort pulse laser with solid target has been investigated by experiment. P-polarized light irradiating 5 mm Cu slab with 45 degree, the hard X-ray with energy of 200 keV has been detected. Fitting the experiment data by Maxwellian distribution, the temperature of hot electron is 67 keV. The experiment data are the results of combination of several absorption mechanisms

  1. Theoretical analysis of the background intensity distribution in X-ray Birefringence Imaging using synchrotron bending-magnet radiation

    Science.gov (United States)

    Sutter, John P.; Dolbnya, Igor P.; Collins, Stephen P.; Harris, Kenneth D. M.; Edwards-Gau, Gregory R.; Palmer, Benjamin A.

    2015-04-01

    In the recently developed technique of X-ray Birefringence Imaging, molecular orientational order in anisotropic materials is studied by exploiting the birefringence of linearly polarized X-rays with energy close to an absorption edge of an element in the material. In the experimental setup, a vertically deflecting high-resolution double-crystal monochromator is used upstream from the sample to select the appropriate photon energy, and a horizontally deflecting X-ray polarization analyzer, consisting of a perfect single crystal with a Bragg reflection at Bragg angle of approximately 45°, is placed downstream from the sample to measure the resulting rotation of the X-ray polarization. However, if the experiment is performed on a synchrotron bending-magnet beamline, then the elliptical polarization of the X-rays out of the electron orbit plane affects the shape of the output beam. Also, because the monochromator introduces a correlation between vertical position and photon energy to the X-ray beam, the polarization analyzer does not select the entire beam, but instead selects a diagonal stripe, the slope of which depends on the Bragg angles of the monochromator and the polarization analyzer. In the present work, the final background intensity distribution is calculated analytically because the phase space sampling methods normally used in ray traces are too inefficient for this setup. X-ray Birefringence Imaging data measured at the Diamond Light Source beamline B16 agree well with the theory developed here.

  2. Theoretical analysis of the background intensity distribution in X-ray Birefringence Imaging using synchrotron bending-magnet radiation

    Energy Technology Data Exchange (ETDEWEB)

    Sutter, John P., E-mail: john.sutter@diamond.ac.uk; Dolbnya, Igor P.; Collins, Stephen P. [Diamond Light Source Ltd., Chilton, Didcot, Oxfordshire OX11 0DE (United Kingdom); Harris, Kenneth D. M.; Edwards-Gau, Gregory R. [School of Chemistry, Cardiff University, Park Place, Cardiff CF10 3AT, Wales (United Kingdom); Palmer, Benjamin A. [Department of Structural Biology, Weizmann Institute of Science, 234 Herzl St., Rehovot 7610001 (Israel)

    2015-04-28

    In the recently developed technique of X-ray Birefringence Imaging, molecular orientational order in anisotropic materials is studied by exploiting the birefringence of linearly polarized X-rays with energy close to an absorption edge of an element in the material. In the experimental setup, a vertically deflecting high-resolution double-crystal monochromator is used upstream from the sample to select the appropriate photon energy, and a horizontally deflecting X-ray polarization analyzer, consisting of a perfect single crystal with a Bragg reflection at Bragg angle of approximately 45°, is placed downstream from the sample to measure the resulting rotation of the X-ray polarization. However, if the experiment is performed on a synchrotron bending-magnet beamline, then the elliptical polarization of the X-rays out of the electron orbit plane affects the shape of the output beam. Also, because the monochromator introduces a correlation between vertical position and photon energy to the X-ray beam, the polarization analyzer does not select the entire beam, but instead selects a diagonal stripe, the slope of which depends on the Bragg angles of the monochromator and the polarization analyzer. In the present work, the final background intensity distribution is calculated analytically because the phase space sampling methods normally used in ray traces are too inefficient for this setup. X-ray Birefringence Imaging data measured at the Diamond Light Source beamline B16 agree well with the theory developed here.

  3. High-intensity X-rays interaction with matter processes in plasmas, clusters, molecules and solids

    CERN Document Server

    Hau-Riege, Stefan P

    2012-01-01

    Filling the need for a book bridging the effect of matter on X-ray radiation and the interaction of x-rays with plasmas, this monograph provides comprehensive coverage of the topic. As such, it presents and explains such powerful new X-ray sources as X-ray free-electron lasers, as well as short pulse interactions with solids, clusters, molecules, and plasmas, and X-ray matter interactions as a diagnostic tool. Equally useful for researchers and practitioners working in the field.

  4. Numerical simulations of the hard X-ray pulse intensity distribution at the Linac Coherent Light Source.

    Science.gov (United States)

    Pardini, Tom; Aquila, Andrew; Boutet, Sébastien; Cocco, Daniele; Hau-Riege, Stefan P

    2017-07-01

    Numerical simulations of the current and future pulse intensity distributions at selected locations along the Far Experimental Hall, the hard X-ray section of the Linac Coherent Light Source (LCLS), are provided. Estimates are given for the pulse fluence, energy and size in and out of focus, taking into account effects due to the experimentally measured divergence of the X-ray beam, and measured figure errors of all X-ray optics in the beam path. Out-of-focus results are validated by comparison with experimental data. Previous work is expanded on, providing quantitatively correct predictions of the pulse intensity distribution. Numerical estimates in focus are particularly important given that the latter cannot be measured with direct imaging techniques due to detector damage. Finally, novel numerical estimates of improvements to the pulse intensity distribution expected as part of the on-going upgrade of the LCLS X-ray transport system are provided. We suggest how the new generation of X-ray optics to be installed would outperform the old one, satisfying the tight requirements imposed by X-ray free-electron laser facilities.

  5. A photodiode amplifier system for pulse-by-pulse intensity measurement of an x-ray free electron laser.

    Science.gov (United States)

    Kudo, Togo; Tono, Kensuke; Yabashi, Makina; Togashi, Tadashi; Sato, Takahiro; Inubushi, Yuichi; Omodani, Motohiko; Kirihara, Yoichi; Matsushita, Tomohiro; Kobayashi, Kazuo; Yamaga, Mitsuhiro; Uchiyama, Sadayuki; Hatsui, Takaki

    2012-04-01

    We have developed a single-shot intensity-measurement system using a silicon positive-intrinsic-negative (PIN) photodiode for x-ray pulses from an x-ray free electron laser. A wide dynamic range (10(3)-10(11) photons/pulse) and long distance signal transmission (>100 m) were required for this measurement system. For this purpose, we developed charge-sensitive and shaping amplifiers, which can process charge pulses with a wide dynamic range and variable durations (ns-μs) and charge levels (pC-μC). Output signals from the amplifiers were transmitted to a data acquisition system through a long cable in the form of a differential signal. The x-ray pulse intensities were calculated from the peak values of the signals by a waveform fitting procedure. This system can measure 10(3)-10(9) photons/pulse of ~10 keV x-rays by direct irradiation of a silicon PIN photodiode, and from 10(7)-10(11) photons/pulse by detecting the x-rays scattered by a diamond film using the silicon PIN photodiode. This system gives a relative accuracy of ~10(-3) with a proper gain setting of the amplifiers for each measurement. Using this system, we succeeded in detecting weak light at the developmental phase of the light source, as well as intense light during lasing of the x-ray free electron laser. © 2012 American Institute of Physics

  6. Size dependent ionization dynamics of argon clusters in intense x-ray pulses

    Science.gov (United States)

    Schorb, Sebastian; Rupp, D.; Swiggers, M.; Coffee, R. N.; Messerschmidt, M.; Williams, G.; Bozek, J. D.; Wada, S.-I.; Möller, T.; Bostedt, C.

    2012-06-01

    Free Electron Lasers open the door for novel experiments in many science areas ranging from ultrafast chemical dynamics to single shot imaging of molecules. For the success of virtually all experiments with free electron lasers a detailed understanding of the light - matter interaction in the x-ray regime is pivotal. The Linac Coherent Light Source (LCLS) free electron laser in Stanford allows for the first time to study innershell ionization dynamics of intense x-ray pulses on a femtosecond time scale. We performed experiments on the ionization dynamics of Argon clusters at different pulse length using the slotted spoiler foil in the second LCLS bunch compressor [1]. The Auger rate of argon clusters is predicted to be size dependent and lower than in atoms due to delocalization of the valence electrons [2]. We observe a dependence of the ionization dynamics on pulse length and cluster size. The results are discussed and also compared to recent atomic and molecular data from LCLS.[4pt] [1] P. Emma et al. PRL 92, 074801 (2004)[0pt] [2] U. Saalmann, JM Rost PRL 89, 14 (2002)

  7. Windowless microfluidic platform based on capillary burst valves for high intensity x-ray measurements

    Energy Technology Data Exchange (ETDEWEB)

    Vig, Asger Laurberg; Enevoldsen, Nikolaj; Thilsted, Anil Haraksingh; Eriksen, Johan; Kristensen, Anders [Department of Micro and Nanotechnology, DTU Nanotech, Technical University of Denmark, Building 345east, Orsteds Plads, DK-2800 Kongens Lyngby (Denmark); Haldrup, Kristoffer; Feidenhans' l, Robert; Nielsen, Martin Meedom [Centre for Molecular Movies, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen East (Denmark)

    2009-11-15

    We propose and describe a microfluidic system for high intensity x-ray measurements. The required open access to a microfluidic channel is provided by an out-of-plane capillary burst valve (CBV). The functionality of the out-of-plane CBV is characterized with respect to the diameter of the windowless access hole, ranging from 10 to 130 {mu}m. Maximum driving pressures from 22 to 280 mbar corresponding to refresh rates of the exposed sample from 300 Hz to 54 kHz is demonstrated. The microfluidic system is tested at beamline ID09b at the ESRF synchrotron radiation facility in Grenoble, and x-ray scattering measurements are shown to be feasible and to require only very limited amounts of sample, <1 ml/h of measurements without recapturing of sample. With small adjustments of the present chip design, scattering angles up to 30 deg. can be achieved without shadowing effects and integration on-chip mixing and spectroscopy appears straightforward.

  8. Fast GPU-based absolute intensity determination for energy-dispersive X-ray Laue diffraction

    Science.gov (United States)

    Alghabi, F.; Send, S.; Schipper, U.; Abboud, A.; Pietsch, U.; Kolb, A.

    2016-01-01

    This paper presents a novel method for fast determination of absolute intensities in the sites of Laue spots generated by a tetragonal hen egg-white lysozyme crystal after exposure to white synchrotron radiation during an energy-dispersive X-ray Laue diffraction experiment. The Laue spots are taken by means of an energy-dispersive X-ray 2D pnCCD detector. Current pnCCD detectors have a spatial resolution of 384 × 384 pixels of size 75 × 75 μm2 each and operate at a maximum of 400 Hz. Future devices are going to have higher spatial resolution and frame rates. The proposed method runs on a computer equipped with multiple Graphics Processing Units (GPUs) which provide fast and parallel processing capabilities. Accordingly, our GPU-based algorithm exploits these capabilities to further analyse the Laue spots of the sample. The main contribution of the paper is therefore an alternative algorithm for determining absolute intensities of Laue spots which are themselves computed from a sequence of pnCCD frames. Moreover, a new method for integrating spectral peak intensities and improved background correction, a different way of calculating mean count rate of the background signal and also a new method for n-dimensional Poisson fitting are presented.We present a comparison of the quality of results from the GPU-based algorithm with the quality of results from a prior (base) algorithm running on CPU. This comparison shows that our algorithm is able to produce results with at least the same quality as the base algorithm. Furthermore, the GPU-based algorithm is able to speed up one of the most time-consuming parts of the base algorithm, which is n-dimensional Poisson fitting, by a factor of more than 3. Also, the entire procedure of extracting Laue spots' positions, energies and absolute intensities from a raw dataset of pnCCD frames is accelerated by a factor of more than 3.

  9. X-ray tomography investigation of intensive sheared Al–SiC metal matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    De Giovanni, Mario; Warnett, Jason M.; Williams, Mark A. [WMG, University of Warwick, Coventry CV4 7AL (United Kingdom); Haribabu, Nadendla [BCAST, Brunel University London, Uxbridge UB8 3PH (United Kingdom); Srirangam, Prakash, E-mail: p.srirangam@warwick.ac.uk [WMG, University of Warwick, Coventry CV4 7AL (United Kingdom)

    2015-12-15

    X-ray computed tomography (XCT) was used to characterise three dimensional internal structure of Al–SiC metal matrix composites. The alloy composite was prepared by casting method with the application of intensive shearing to uniformly disperse SiC particles in the matrix. Visualisation of SiC clusters as well as porosity distribution were evaluated and compared with non-shearing samples. Results showed that the average particle size as well as agglomerate size is smaller in sheared sample compared to conventional cast samples. Further, it was observed that the volume fraction of porosity was reduced by 50% compared to conventional casting, confirming that the intensive shearing helps in deagglomeration of particle clusters and decrease in porosity of Al–SiC metal matrix composites. - Highlights: • XCT was used to visualise 3D internal structure of Al-SiC MMC. • Al-SiC MMC was prepared by casting with the application of intensive shearing. • SiC particles and porosity distribution were evaluated. • Results show shearing deagglomerates particle clusters and reduces porosity in MMC.

  10. Nonlinear increase of X-ray intensities from thin foils irradiated with a 200 TW femtosecond laser.

    Science.gov (United States)

    Faenov, A Ya; Colgan, J; Hansen, S B; Zhidkov, A; Pikuz, T A; Nishiuchi, M; Pikuz, S A; Skobelev, I Yu; Abdallah, J; Sakaki, H; Sagisaka, A; Pirozhkov, A S; Ogura, K; Fukuda, Y; Kanasaki, M; Hasegawa, N; Nishikino, M; Kando, M; Watanabe, Y; Kawachi, T; Masuda, S; Hosokai, T; Kodama, R; Kondo, K

    2015-09-02

    We report, for the first time, that the energy of femtosecond optical laser pulses, E, with relativistic intensities I > 10(21)  W/cm(2) is efficiently converted to X-ray radiation, which is emitted by "hot" electron component in collision-less processes and heats the solid density plasma periphery. As shown by direct high-resolution spectroscopic measurements X-ray radiation from plasma periphery exhibits unusual non-linear growth ~E(4-5) of its power. The non-linear power growth occurs far earlier than the known regime when the radiation reaction dominates particle motion (RDR). Nevertheless, the radiation is shown to dominate the kinetics of the plasma periphery, changing in this regime (now labeled RDKR) the physical picture of the laser plasma interaction. Although in the experiments reported here we demonstrated by observation of KK hollow ions that X-ray intensities in the keV range exceeds ~10(17)  W/cm(2), there is no theoretical limit of the radiation power. Therefore, such powerful X-ray sources can produce and probe exotic material states with high densities and multiple inner-shell electron excitations even for higher Z elements. Femtosecond laser-produced plasmas may thus provide unique ultra-bright X-ray sources, for future studies of matter in extreme conditions, material science studies, and radiography of biological systems.

  11. Ultrafast dynamics driven by intense light pulses from atoms to solids, from lasers to intense X-rays

    CERN Document Server

    Gräfe, Stefanie

    2016-01-01

    This book documents the recent vivid developments in the research field of ultrashort intense light pulses for probing and controlling ultrafast dynamics. The recent fascinating results in studying and controlling ultrafast dynamics in ever more complicated systems such as (bio-)molecules and structures of meso- to macroscopic sizes on ever shorter time-scales are presented. The book is written by some of the most eminent experimental and theoretical experts in the field. It covers the new groundbreaking research directions that were opened by the availability of new light sources such as fully controlled intense laser fields with durations down to a single oscillation cycle, short-wavelength laser-driven attosecond pulses and intense X-ray pulses from the upcoming free electron lasers. These light sources allowed the investigation of dynamics in atoms, molecules, clusters, on surfaces and very recently also in nanostructures and solids in new regimes of parameters which, in turn, led to the identification of...

  12. Jovian X-ray emissions

    Science.gov (United States)

    Waite, J. H.; Lewis, W. S.; Gladstone, G. R.; Fabian, A. C.; Brandt, W. N.

    1996-01-01

    The Einstein and Rosat observations of X-ray emissions from Jupiter are summarized. Jupiter's soft X-ray emission is observed to originate from the planet's auroral zones, and specifically, from its equatorial region. The processes responsible for these emissions are not established. The brightness distribution of the Jovian X-rays is characterized by the dependence on central meridian longitude and by north-south and morning-afternoon asymmetries. The X-rays observed during the impact of the comet Shoemaker-Levy 9 are believed to be impact-induced brightenings of the X-ray aurora.

  13. Characterization of high intensity Ni-like X-ray lasers and their application experiment

    Energy Technology Data Exchange (ETDEWEB)

    Tang, H.J.; Daido, H.; Suzuki, M. [Osaka Univ., Suita (Japan). Inst. of Laser Engineering; Japan Atomic Energy Research Inst., Kyoto (Japan). Advanced Photon Research Center; Yamagami, S.; Nagai, K.; Norimatsu, T.; Mima, K.; Yamanaka, T. [Osaka Univ., Suita (Japan). Inst. of Laser Engineering; Kato, Y.; Sasaki, A.; Hasegawa, N. [Japan Atomic Energy Research Inst., Kyoto (Japan). Advanced Photon Research Center; Wang, S.; Gu, Y.; Huang, G. [National Lab. on High Power Laser and Physics, Shanghai, SH (China); Carillon, A.; Ros, D.; Fourcade, P.; Jamelot, G. [Lab. de Spectroscopie Atomique et Ionique, Univ. Paris-Sud, Orsay (France); Joyeux, D.; Phalippou, D. [Lab. Charles Fabry, CNRS, Inst. d' Optique, Orsay (France); Murai, K. [Osaka National Research Inst., Ikeda, Osaka (Japan); Butzbach, R.; Uschmann, I.; Foerster, E. [IOQ, Friedrich-Schiller Univ., Jena (Germany); Namikawa, K.; Tai, R. [Tokyo Gakugei Univ., Koganei (Japan); Koike, F. [Kitasato Univ., Sagamihara, Kanagawa (Japan). School of Medicine; Takenaka, H. [NTT Advanced Technology, Musashino (Japan); Zhang, G. [Inst. of Applied Physics and Computational Mathematics, Beijing, BJ (China); Choi, I.W. [Korea Advanced Inst. of Science and Technology, Taejon (Korea)

    2001-07-01

    At the Institute of Laser Engineering, Osaka University, we have obtained Ni-like X-ray lasers of various atomic number elements, including many shorter wavelength Ni-like lasing lines around 5 nm. The saturated amplification of Ni-like Ag lasing line at the wavelength of 13.9 nm have been observed. Using these X-ray lasers, we are preparing the application experiments such as probing a laser-produced plasma with an X-ray laser interferometer. (orig.)

  14. Influence of Polarization of the Incident Beam on Integrated Intensities in X-Ray Energy-Dispersive Diffractometry

    DEFF Research Database (Denmark)

    Olsen, J. Staun; Buras, B.; Jensen, T.

    1978-01-01

    Polarization measurements of the primary X-ray beam produced by thick copper and tungsten anodes are reported and formulas derived for integrated intensities of Bragg reflections in energy-dispersive diffractometry with the polarization of the primary beam taken into account. It was found...

  15. Prediction and Measurement of X-Ray Spectral and Intensity Distributions from Low Energy Electron Impact Sources

    Science.gov (United States)

    Edwards, David L.

    1999-01-01

    In-vacuum electron beam welding is a technology that NASA considered as a joining technique for manufacture of space structures. The interaction of energetic electrons with metal produces x-rays. The radiation exposure to astronauts performing the in-vacuum electron beam welding must be characterized and minimized to insure safe operating conditions. This investigation characterized the x-ray environment due to operation of an in-vacuum electron beam welding tool. NASA, in a joint venture with the Russian Space Agency, was scheduled to perform a series of welding in space experiments on board the United States Space Shuttle. This series of experiments was named the International Space Welding Experiment (ISWE). The hardware associated with the ISWE was leased to NASA, by the Paton Welding Institute (PWI) in Ukraine, for ground based welding experiments in preparation for flight. Two tests were scheduled, using the ISWE electron beam welding tool, to characterize the radiation exposure to an astronaut during the operation of the ISWE. These radiation exposure tests consisted of Thermoluminescence Dosimeters (TLD's) shielded with material currently used by astronauts during Extra Vehicular Activities (EVA) and exposed to x-ray radiation generated by operation of an in-vacuum electron beam welding tool. This investigation was the first known application of TLD's to measure absorbed dose from x-rays of energy less than 10 KeV. The ISWE hardware was returned to Ukraine before the issue of adequate shielding for the astronauts was verified. Therefore, alternate experimental and analytical methods were developed to measure and predict the x-ray spectral and intensity distribution generated by electron impact with metal. These x-ray spectra were used to calculate the absorbed radiation dose to astronauts. These absorbed dose values were compared to TLD measurements obtained during actual operation of the in-vacuum electron beam welding tool. The calculated absorbed dose

  16. Analytical reconstructions of intensity modulated x-ray phase-contrast imaging of human scale phantoms

    Science.gov (United States)

    Włodarczyk, Bartłomiej; Pietrzak, Jakub

    2015-01-01

    This paper presents analytical approach to modeling of a full planar and volumetric acquisition system with image reconstructions originated from partial illumination x-ray phase-contrast imaging at a human scale using graphics processor units. The model is based on x-ray tracing and wave optics methods to develop a numerical framework for predicting the performance of a preclinical phase-contrast imaging system of a human-scaled phantom. In this study, experimental images of simple numerical phantoms and high resolution anthropomorphic phantoms of head and thorax based on non-uniform rational b-spline shapes (NURBS) prove the correctness of the model. Presented results can be used to simulate the performance of partial illumination x-ray phase-contrast imaging system on various preclinical applications. PMID:26600991

  17. Photoneutron intensity variation with field size around radiotherapy linear accelerator 18-MeV X-ray beam

    Energy Technology Data Exchange (ETDEWEB)

    Al-Ghamdi, H.; Fazal-ur-Rehman [Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Al-Jarallah, M.I. [Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)], E-mail: mibrahim@kfupm.edu.sa; Maalej, N. [Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)

    2008-08-15

    In X-ray radiotherapy accelerators, neutrons are produced mainly by ({gamma},n) reaction when high energy X-rays interact with high Z materials of the linear accelerator head. These materials include the lead (Pb) used as shielding in the collimator, tungsten (W) target used for the production of X-rays and iron (Fe) in the accelerator head. These unwanted neutrons contaminate the therapeutic beam and contribute to the patient dose during the treatment of a cancer patient. Knowing the neutron distribution around the radiotherapy accelerator is therefore desired. CR-39 nuclear track detectors (NTDs) were used to study the variation of fast and thermal neutron relative intensities around an 18 MeV linear accelerator X-ray beam with the field sizes of 0, 10x10, 20x20, 30x30 and 40x40cm{sup 2}. For fast neutron detection, bare NTDs were used. For thermal neutron detection, NTDs were covered with lithium tetra borate (Li{sub 2}B{sub 4}O{sub 7}) converters. The NTDs were placed at different locations in the direction perpendicular to the treatment couch (transversal) and in the direction parallel to the treatment couch (longitudinal) with respect to the isocenter of the accelerator. The fast neutron relative intensity is symmetrical about the beam axis and exhibits an exponential-like drop with distance from the isocenter of the accelerator for all the field sizes. At the primary beam (isocenter), the relative fast neutron intensity is highest for 40x40cm{sup 2} field size and decreases linearly with the decrease in the field size. However, fast neutron intensities do not change significantly with beam size for the measurements outside the primary beam. The fast neutron intensity in the longitudinal direction outside the primary beam decreases linearly with the field size. The thermal neutron intensity, at any location, was found to be almost independent of the field size.

  18. Energy dependence of normal branch quasi-periodic intensity oscillations in low-mass X-ray binaries

    Science.gov (United States)

    Miller, Guy S.; Lamb, Frederick K.

    1992-01-01

    The properties of the approximately 6 Hz quasi-periodic X-ray intensity oscillations observed in the low-mass X-ray binary Cyg X-2 when it is on the normal spectral branch are shown to be consistent with a model in which photons from a central source with a fixed spectrum are Comptonized by an oscillating radial inflow. As the electron scattering optical depth of the flow varies, the spectrum of the escaping X-rays appears to rotate about a pivot energy that depends mainly on the electron temperature in the flow. The temperature derived from the observed energy dependence of the Cyg X-2 normal branch oscillations is approximately 1 keV, in good agreement with the estimated Compton temperature of its X-ray spectrum. The mean optical depth tau of the Comptonizing flow is inferred to be about 10, while the change in tau over an oscillation is estimated to be about 1; both values are in good agreement with radiation hydrodcode simulations of the radial flow.

  19. Hard X-ray dose intensity and spatial distribution in a plasma focus ...

    Indian Academy of Sciences (India)

    type PF device in various pressures of argon as the operating gas were studied. The PF device was powered by a 12 F capacitor at 25 kV charging voltage. Time-integrated hard X-ray (HXR) emission was investigated using thermoluminescence ...

  20. Generation of intense soft X-rays from capillary discharge plasmas

    Indian Academy of Sciences (India)

    micron scale lengths (articles from .... The X-ray radiation passes through the aperture in the ground electrode and an orifice (dia ∼1 mm) kept ... The noise appearing in the current pulse may be mainly due to the breakdown in the in spark ...

  1. Hard X-ray dose intensity and spatial distribution in a plasma focus ...

    Indian Academy of Sciences (India)

    Hard X-rays; plasma focus; thermoluminescence dosimeter; argon gas; scintillator detector. PACS Nos 52.58.Lq; 52.59.Hq. 1. Introduction. Plasma focus (PF) devices are coaxial guns consisting of two cylindrical electrodes placed in a chamber filled with a few mbar of gas. These devices have been built with capacitor.

  2. Fracture of metals samples under conditions of fast heating by intensive X-ray radiation

    Directory of Open Access Journals (Sweden)

    Golubev V.K.

    2012-08-01

    Full Text Available Results on studying the fracture of metals samples in the form of thin disks under fast heating by the X-ray pulse with the complete spectrum are presented in the paper. The samples of such metals as iron, copper, AMg6 aluminum, VT14 titanium, molybdenum, tungsten, cadmium, lead and zinc were tested. The samples were fixed in the special cartridges equipped with the gauges of a mechanical recoil momentum. The cartridges with samples were placed at such distances from the X-ray irradiator where the energy fluxes were 1.38, 0.90 and 0.29kJ/cm2. The irradiating X-ray pulse was about 2 ns in duration. After testing, the depth of material ablation from a sample front surface and the degree and character of its spall damage were determined. The method of metallographic analysis was used for these purposes. Numerical calculations of loading conditions were made with the use of an equation of state taking into account the process of evaporation. The calculated value of maximum negative pressure in the sample at the coordinate corresponding to the formation of spallation zones or spall cracks was conventionally accepted as the material resistance to spall fracture. The comparison of obtained results with the data on the fracture of examined materials in the conditions of fast heating by the X-ray pulse with the hard spectrum and a high-current electron beam was conducted.

  3. Approximated transport-of-intensity equation for coded-aperture x-ray phase-contrast imaging.

    Science.gov (United States)

    Das, Mini; Liang, Zhihua

    2014-09-15

    Transport-of-intensity equations (TIEs) allow better understanding of image formation and assist in simplifying the "phase problem" associated with phase-sensitive x-ray measurements. In this Letter, we present for the first time to our knowledge a simplified form of TIE that models x-ray differential phase-contrast (DPC) imaging with coded-aperture (CA) geometry. The validity of our approximation is demonstrated through comparison with an exact TIE in numerical simulations. The relative contributions of absorption, phase, and differential phase to the acquired phase-sensitive intensity images are made readily apparent with the approximate TIE, which may prove useful for solving the inverse phase-retrieval problem associated with these CA geometry based DPC.

  4. Doses in the vicinity of mobile x-ray equipment in a children's intensive care unit

    Energy Technology Data Exchange (ETDEWEB)

    Milkovic, D. [Hospital of Lung Diseases for the Children and Youth, Srebrnjak, Zagreb (Croatia); Knezevic, Z.; Ranogajec-Komor, M. [Ruder Boskovic Institute, Zagreb (Croatia); Bozinovic, D. [Clinic for Infectius Diseases ' Dr. Fran Mihaljevic' , Zagreb (Croatia)

    2000-05-01

    Most of the patients in the Intensive Care Unit for Children are new-borns and infants having an infection of the central nervous system, with systemic septic and respiratory infections. Therefore, mobile X-ray equipment is routinely used for diagnosis of the respiratory tract, heart and endovascular catheterization. The aim of this work was to determine the radiation exposure to children in the vicinity of the exposed patient in the same or next room. The mobile X-ray unit is a Phillips Practix 100 model, including mobile shields (made by the firm Weimer Strahlenschutz) for radiation protection of patients and personal. For dose measurements, a thermoluminescent dosimetry system with TLD-700 detectors (manufactured by Harshaw) and a microprocessor controlled TOLEDO 654 reader were used. Three measurement runs were carried out. In the first one, the dosimeters were placed on the bed, without the patient, and the x-ray unit was operated as for thoracic x-ray. The results show the adequate homogeneity of the irradiation field. In the second measurement run, dosimeters were placed on the neighbouring bed behind the shield as well as on the glass wall of the room at various heights and distances from the X-ray tube. The results show that doses are very low, practically in the range of the lowest detectable dose, about 5 {mu}Sv. In the 3rd measurement run, the configuration of dosimeters in the surroundings were the same, but the irradiation was carried out with a 2 year old female patient and the distribution of the patient's surface dose was measured. The entrance dose on the breast was found to be 0.17 mSv. The results of this study show that the exposure of children to radiation in the vicinity of the exposed patient in the same or next room is not measurable. Therefore there is no basis for the risk estimation of genetic, leukemogenic and cancerogenic detriment. (author)

  5. L X-ray intensity ratio measurements using selective L sub-shell photo-ionisation on synchrotron

    Science.gov (United States)

    Bansal, Himani; Tiwari, M. K.; Mittal, Raj

    2017-10-01

    Lα/Lℓ, Lβ /Lℓ and Lγ/Lℓ intensity ratios have been measured for elements in the range 66≤Z≤83 at tuned photon energies on synchrotron beam line-16 at Indus-2, India. For each element, three incident energies Ei were E3; EL3 EL1 where ELi are Li absorption edge energies of the element. Emitted L X-ray spectrum of an element constitutes a number of X-ray lines generally grouped into four main groups due to limited resolution of available detectors as Lℓ(L3-M1), Lα(L3-M4,5), Lβ(L1-M2,3,4,5,N4; L2-M3,4; L3-N1,4,5,O1,4,5) and Lγ(L2-N1,4,O1,4; L1-N2,3,5,O3,2). Lα and Lℓ both comprise only the lines feeding L3 level and Lβ group comprises X-ray lines feeding all the three sub-shells where as Lγ involves contribution from L1 and L2 feedings. Only E3 excitation gives the ratios free from intra sub-shell Coster-Kronig (CK) transitions while excitations E2 and E1 give CK affected Lβ/Lℓ and Lγ/Lℓ X-ray intensity ratios and Lα/Lℓ still remains free from CKs. The pattern of intensity ratios at three excitation energies of elements was well interpreted in terms of on/off of CK transitions (Bambynek et al., 1972; Campbell, 2003) and outer shell electron filling configuration (Scofield, 1973).

  6. Modeling Relativistic Electron Precipitation Bremsstrahlung X-Ray Intensities at 10-100 km Manned Vehicle Altitudes

    Science.gov (United States)

    Habash Krause, L.; Gilchrist, B. E.; Nishikawa, K.; Williams, A.

    2013-12-01

    Relativistic electron precipitation (REP) events occur when beams or bunches of relativistic electrons of magnetospheric origin enter the Earth's atmosphere, typically at auroral latitudes. REP events are associated with a variety of space weather effects, including production of transitional and bremsstrahlung radiation, catalytic depletion of stratospheric ozone, and scintillation of transionospheric radio waves. This study examines the intensities of x-rays produced at airliner, manned balloon, and suborbital Reusable Launch Vehicle (sRLV) altitudes. The monoenergetic beam is modeled in cylindrical symmetry using the paraxial ray equation. Bremsstrahlung photon production is calculated using the traditional Sauter-Elwert cross-section, providing x-ray emission spectra differential in energy and angle. Attenuation is computed for a plane-stratified standard atmosphere, and the loss processes include photoionization, Rayleigh and Compton scattering, electron-positron pair production, and photonuclear interaction. Peak altitudes of electron energy deposition and bremsstrahlung x-ray production were calculated for beams of energies from 1 MeV through 100 MeV. The altitude peak of bremsstrahlung deposition was consistently and significantly lower that that of the electron deposition due to the longer mean free paths of x-rays compared to electrons within the atmosphere. For example, for a nadir-directed monoenergetic 5 MeV beam, the peak deposition altitude was calculated to be 42 km, but the resulting bremmstrahlung deposition peaked at 25 km. This has implications for crew and passenger safety, especially with the growth of the space tourism industry that relies on sRLVs with a nominal apogee of 100 km. A survey of results covering the 1-100 MeV spectrum for the three altitude ranges of interest will be presented.

  7. Modeling Relativistic Electron Precipitation Bremsstrahlung X-Ray Intensities at 10-100 km Manned Vehicle Altitudes

    Science.gov (United States)

    Krause, L. Habsh; Gilchrist, B. E.; Nishikawa, Ken-Ichi

    2013-01-01

    Relativisitic electron precipitation (REP) events occur when beams or bunches of relativistic electrons of magnetospheric origin enter the Earth's atmosphere, typically at auroral latitudes. REP events are associated with a variety of space weather effects, including production of transitional and bremsstrahlung radiation, catalytic depletion of stratospheric ozone, and scintillation of transionospheric radio waves. This study examines the intensities of x-rays produced at airliner, manned balloon, and space reuseable launch vehicles (sRLVs). The monoenergetic beam is modeled in cylindrical symetry using the paraxial ray equation. Bremsstrahlung photon production is calculated using the traditional Sauter-Elwert cross-section, providing x-ray emission spectra differential in energy and angle. Attenuation is computed for a plane-stratified standard atmosphere, and the loss processes include photoionization, Rayleigh and Compton scattering, electron-positron pair production, and photonuclear interaction. Peak altitudes of electron energy deposition and bremsstrahlung x-ray production were calculated for beams of energies from 1 MeV through 100 MeV. The altitude peak of bremsstrahlung deposition was consistently and significantly lower that that of the electron deposition due to the longer mean free paths of x-rays compared to electrons within the atmosphere. For example, for a nadir-directed monoenergetic 5 MeV beam, the peak deposition altitude was calculated to be 42 km, but the resulting bremsstrahlung deposition peaked at 25 km. This has implications for crew and passenger safety, especially with the growth of the space tourism industry. A survey of results covering the 1-100 MeV spectrum for the three altitude ranges of interest will be presented.

  8. Charge transfer in dissociating iodomethane and fluoromethane molecules ionized by intense femtosecond X-ray pulses

    Directory of Open Access Journals (Sweden)

    Rebecca Boll

    2016-07-01

    Full Text Available Ultrafast electron transfer in dissociating iodomethane and fluoromethane molecules was studied at the Linac Coherent Light Source free-electron laser using an ultraviolet-pump, X-ray-probe scheme. The results for both molecules are discussed with respect to the nature of their UV excitation and different chemical properties. Signatures of long-distance intramolecular charge transfer are observed for both species, and a quantitative analysis of its distance dependence in iodomethane is carried out for charge states up to I21+. The reconstructed critical distances for electron transfer are in good agreement with a classical over-the-barrier model and with an earlier experiment employing a near-infrared pump pulse.

  9. Spectral analysis of x-ray emission created by intense laser irradiation of copper materials

    Energy Technology Data Exchange (ETDEWEB)

    Huntington, C. M.; Kuranz, C. C.; Drake, R. P. [Atmospheric, Oceanic, Space Science, University of Michigan, Ann Arbor, Michigan 48103 (United States); Malamud, G. [Atmospheric, Oceanic, Space Science, University of Michigan, Ann Arbor, Michigan 48103 (United States); Department of Physics, Nuclear Research Center - Negev, 84190 Beer-Sheva (Israel); Park, H.-S.; Maddox, B. R. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States)

    2012-10-15

    We have measured the x-ray emission, primarily from K{sub {alpha}},K{sub {beta}}, and He{sub {alpha}} lines, of elemental copper foil and 'foam' targets irradiated with a mid-10{sup 16} W/cm{sup 2} laser pulse. The copper foam at 0.1 times solid density is observed to produce 50% greater He{sub {alpha}} line emission than copper foil, and the measured signal is well-fit by a sum of three synthetic spectra generated by the atomic physics code FLYCHK. Additionally, spectra from both targets reveal characteristic inner shell K{sub {alpha}} transitions from hot electron interaction with the bulk copper. However, only the larger-volume foam target produced significant K{sub {beta}} radiation, confirming a lower bulk temperature in the higher volume sample.

  10. Multilayer-coated photodiode-based beam intensity monitor for polarization analysis of plasma soft X-ray laser.

    Science.gov (United States)

    Imazono, Takashi

    2017-07-20

    A Mo/Si multilayer-coated photodiode detector (MP) for beam intensity monitoring was prototyped and characterized using synchrotron radiation and X-ray laser (XRL) sources in order to perform polarization analysis of a laser-driven plasma soft XRL generated from nickel-like silver plasma. At a wavelength of 13.9 nm and an angle of incidence of 45°, the s-polarization reflectance is 0.525 and shows a strong positive correlation with the transmittance, corresponding to the photodiode current generated by the MP. We succeeded in performing polarization analysis of XRL beams with a large shot-to-shot intensity variation using the MP. Thus, this MP enables shot-to-shot monitoring and delivery of high intensity beams for downstream XRL experiments.

  11. Red-detuned, high-intensity, short-duration sweet spot for impulsive X-ray Raman excitation in atoms

    CERN Document Server

    Ware, Matthew R; Haxton, Daniel J

    2016-01-01

    Impulsive X-ray Raman excitations of Lithium, Neon, and Sodium are calculated using the Multiconfiguration Time-Dependent Hartree-Fock method. Using linearly polarized laser pulses without chirp, we determine the optimum central frequency, intensity, and duration for maximum population transfer to valence excited states. We demonstrate the existence of two "sweet spots" for optimum population transfer, either of which, depending on the system, may be superior. The "red-detuned hypothesis" is the proposition that population transfer can be maximized by nonresonant Raman transitions, red-detuned below K-edge, because such detuning minimizes core-excited populations and ionization loss. We find that this hypothesis is verified in the case of Neon -- for Neon, the global optimum for population transfer occurs at high intensity (8 $\\times$ 10$^{19}$ W cm$^{-2}$), short duration (82as full-width-at-half-maximum), and 24eV red-detuned from the K-edge.

  12. X-ray diffraction patterns and diffracted intensity of Kα spectral lines of He-like ions

    Science.gov (United States)

    Goyal, Arun; Khatri, Indu; Singh, A. K.; Sharma, Rinku; Mohan, Man

    2017-09-01

    In the present paper, we have calculated fine-structure energy levels related to the configurations 1s2s, 1s2p, 1s3s and 1s3p by employing GRASP2K code. We have also computed radiative data for transitions from 1s2p 1 P1o, 1s2p 3 P2o, 1s2p 3 P1o and 1s2s 3S1 to the ground state 1s2. We have made comparisons of our presented energy levels and transition wavelengths with available results compiled by NIST and good agreement is achieved. We have also provided X-ray diffraction (XRD) patterns of Kα spectral lines, namely w, x, y and z of Cu XXVIII, Kr XXXV and Mo with diffraction angle and maximum diffracted intensity which is not published elsewhere in the literature. We believe that our presented results may be beneficial in determination of the order parameter, X-ray crystallography, solid-state drug analysis, forensic science, geological and medical applications.

  13. High-intensity x-ray holography: an approach to high-resolution snapshot imaging of biological specimens

    Energy Technology Data Exchange (ETDEWEB)

    Solem, J.C.

    1982-08-01

    The crucial physical and technological issues pertaining to the holographic imaging of biological structures with a short-pulse, high-intensity, high-quantum-energy laser were examined. The limitations of x-ray optics are discussed. Alternative holographic techniques were considered, and it was concluded that far-field Fresnel transform holography (Fraunhofer holography) using a photoresist recording surface is most tractable with near term technology. The hydrodynamic expansion of inhomogeneities within the specimen is discussed. It is shown that expansion is the major source of image blurring. Analytic expressions were derived for the explosion of protein concentrations in an x-ray transparent cytoplasm, compared with numerical calculations, and corrections derived to account for the competitive transport processes by which these inhomogeneities lose energy. It is concluded that for the near term Fresnel transform holography, particularly, far-field or Fraunhofer holography, is more practical than Fourier transform holography. Of the alternative fine grain recording media for use with Fresnel transform holography, a photo-resist is most attractive. For best resolution, exposure times must be limited to a few picoseconds, and this calls for investigation of mechanisms to shutter the laser or gate the recording surface. The best contrast ratio between the nitrogen-bearing polymers (protein and the nucleic acids) and water is between the K-edges of oxygen and nitrogen.

  14. The impact of the in-orbit background and the X-ray source intensity on the centroiding accuracy of the Swift X-ray telescope

    CERN Document Server

    Ambrosi, R M; Hill, J; Cheruvu, C; Abbey, A F; Short, A D T

    2002-01-01

    The optical components of the Swift Gamma Ray Burst Explorer X-ray Telescope (XRT), consisting of the JET-X spare flight mirror and a charge coupled device of the type used in the EPIC program, were used in a re-calibration study carried out at the Panter facility, which is part of the Max Planck Institute for Extraterrestrial Physics. The objective of this study was to check the focal length and the off axis performance of the mirrors and to show that the half energy width (HEW) of the on-axis point spread function (PSF) was of the order of 16 arcsec at 1.5 keV (Nucl. Instr. and Meth. A 488 (2002) 543; SPIE 4140 (2000) 64) and that a centroiding accuracy better that 1 arcsec could be achieved within the 4 arcmin sampling area designated by the Burst Alert Telescope (Nucl. Instr. and Meth. A 488 (2002) 543). The centroiding accuracy of the Swift XRT's optical components was tested as a function of distance from the focus and off axis position of the PSF (Nucl. Instr. and Meth. A 488 (2002) 543). The presence ...

  15. Occurrence of Equatorial Plasma Bubbles during Intense Magnetic Storms

    Directory of Open Access Journals (Sweden)

    Chao-Song Huang

    2011-01-01

    Full Text Available An important issue in low-latitude ionospheric space weather is how magnetic storms affect the generation of equatorial plasma bubbles. In this study, we present the measurements of the ion density and velocity in the evening equatorial ionosphere by the Defense Meteorological Satellite Program (DMSP satellites during 22 intense magnetic storms. The DMSP measurements show that deep ion density depletions (plasma bubbles are generated after the interplanetary magnetic field (IMF turns southward. The time delay between the IMF southward turning and the first DMSP detection of plasma depletions decreases with the minimum value of the IMF Bz, the maximum value of the interplanetary electric field (IEF Ey, and the magnitude of the Dst index. The results of this study provide strong evidence that penetration electric field associated with southward IMF during the main phase of magnetic storms increases the generation of equatorial plasma bubbles in the evening sector.

  16. Comparison of experimental and theoretical X-ray intensities from (In)GaAs specimens investigated by energy-dispersive X-ray spectroscopy in a transmission electron microscope

    Energy Technology Data Exchange (ETDEWEB)

    Walther, T, E-mail: t.walther@sheffield.ac.u [Department of Electronic and Electrical Engineering, University of Sheffield, Sir Frederick Mappin Building, Mappin Street, Sheffield S1 3JD (United Kingdom)

    2010-02-01

    Experimental measurements of X-ray line intensity ratios in a transmission electron microscope are compared over several orders of magnitude of sample thicknesses, from the nm- to the mm- range, with Monte-Carlo simulations using two different software packages. It is shown that the form of the thickness dependence of the K/L ratio of characteristic X-ray lines for GaAs is reproduced qualitatively, but the numerical differences between software packages are large. A scheme is presented for improving the simple k-factor method, taking explicitly into account the thickness dependence that remains even after application of the usual absorption and fluorescence corrections. This is done in first-order approximation by linear regression. The improvement in determining the correct indium concentration in specimens of InGaAs is calculated to be 1at%.

  17. Physical analysis of the shielding capacity for a lightweight apron designed for shielding low intensity scattering X-rays

    Science.gov (United States)

    Kim, Seon Chil; Choi, Jeong Ryeol; Jeon, Byeong Kyou

    2016-07-01

    The purpose of this paper is to develop a lightweight apron that will be used for shielding low intensity radiation in medical imaging radiography room and to apply it to a custom-made effective shielding. The quality of existing aprons made for protecting our bodies from direct radiation are improved so that they are suitable for scattered X-rays. Textiles that prevent bodies from radiation are made by combining barium sulfate and liquid silicon. These materials have the function of shielding radiation in a manner like lead. Three kinds of textiles are produced. The thicknesses of each textile are 0.15 mm, 0.21 mm, and 0.29 mm and the corresponding lead equivalents are 0.039 mmPb, 0.095 mmPb, 0.22 mmPb for each. The rate of shielding space scattering rays are 80% from the distance of 0.5 m, 86% from 1.0 m, and 97% from 1.5 m. If we intend to approach with the purpose of shielding scattering X-rays and low intensity radiations, it is possible to reduce the weight of the apron to be 1/5 compared to that of the existing lead aprons whose weight is typically more than 4 kg. We confirm, therefore, that it is possible to produce lightweight aprons that are used for the purpose of shielding low dose radiations.

  18. Determination of the laser intensity applied to a Ta witness plate from the measured x-ray signal using a pulsed micro-channel plate detector

    Science.gov (United States)

    Pickworth, L. A.; Rosen, M. D.; Schneider, M. B.; Hinkel, D. E.; Benedetti, L. R.; Kauffman, R. L.; Wu, S. S.

    2017-06-01

    The laser intensity distribution at the surface of a high-Z material, such as Ta, can be deduced from imaging the self-emission of the produced x-ray spot using suitable calibration data. This paper presents a calibration method which uses the measured x-ray emissions from laser spots of different intensities hitting a Ta witness plate. The x-ray emission is measured with a micro-channel plate (MCP) based x-ray framing camera plus filters. Data from different positions on one MCP strip or from different MCP assemblies are normalized to each other using a standard candle laser beam spot at ∼1 × 1014 W/cm2 intensity. The distribution of the resulting dataset agrees with results from a pseudo spectroscopic model for laser intensities between 4 and 15 × 1013 W/cm2 . The model is then used to determine the absolute scaling factor between the experimental results from assemblies using two different x-ray filters. The data and model method also allows unique calibration factors for each MCP system and each MCP gain to be compared. We also present simulation results investigating alternate witness plate materials (Ag, Eu and Au).

  19. X-Ray Lasers 2016

    CERN Document Server

    Bulanov, Sergei; Daido, Hiroyuki; Kato, Yoshiaki

    2018-01-01

    These proceedings comprise a selection of invited and contributed papers presented at the 15th International Conference on X-Ray Lasers (ICXRL 2016), held at the Nara Kasugano International Forum, Japan, from May 22 to 27, 2016. This conference was part of an ongoing series dedicated to recent developments in the science and technology of x-ray lasers and other coherent x-ray sources with additional focus on supporting technologies, instrumentation and applications.   The book showcases recent advances in the generation of intense, coherent x-rays, the development of practical devices and their applications across a wide variety of fields. It also discusses emerging topics such as plasma-based x-ray lasers, 4th generation accelerator-based sources and higher harmonic generations, as well as other x-ray generation schemes.

  20. A constrained, total-variation minimization algorithm for low-intensity X-ray CT

    CERN Document Server

    Sidky, Emil Y; Ullberg, Christer; Pan, Xiaochuan

    2010-01-01

    Purpose: We develop an iterative image-reconstruction algorithm for application to low-intensity computed tomography (CT) projection data, which is based on constrained, total-variation (TV) minimization. The algorithm design focuses on recovering structure on length scales comparable to a detector-bin width. Method: Recovering the resolution on the scale of a detector bin, requires that pixel size be much smaller than the bin width. The resulting image array contains many more pixels than data, and this undersampling is overcome with a combination of Fourier upsampling of each projection and the use of constrained, TV-minimization, as suggested by compressive sensing. The presented pseudo-code for solving constrained, TV-minimization is designed to yield an accurate solution to this optimization problem within 100 iterations. Results: The proposed image-reconstruction algorithm is applied to a low-intensity scan of a rabbit with a thin wire, to test resolution. The proposed algorithm is compared with filtere...

  1. Evaluating the Internal Structure of Core-Shell Nanoparticles Using X-ray Photoelectron Intensities and Simulated Spectra.

    Science.gov (United States)

    Chudzicki, M; Werner, W S M; Shard, A G; Wang, Y-C; Castner, D G; Powell, C J

    2015-08-06

    The functionality of a new version of the National Institute of Standards and Technology database Simulation of Electron Spectra for Surface Analysis (SESSA) has been extended by implementing a new geometry engine. The engine enables users to simulate Auger-electron spectra and X-ray photoelectron spectra for different predefined morphologies (planar, islands, spheres, multi-layer core-shell particles). We compared shell thicknesses of core-shell nanoparticles derived from core-shell XPS peak intensities using Shard's method, which allows one to estimate shell thicknesses of core-shell nanoparticles, and a series of SESSA simulations for a wide range of nanoparticle dimensions. We obtained very good agreement of the shell thicknesses for cases where elastic scattering within the shell can be neglected, a result that is in accordance with the underlying assumptions of the Shard model. If elastic-scattering effects are important, there can be thickness uncertainties of up to 25 %. Experimental spectra of functionalized gold nanoparticles obtained by Techane et al. were analyzed with SESSA 2.0 both with respect to the relevant peak intensities as well as the spectral shape. Good agreement between experiment and theory was found for both cases. These results show that the single-sphere model for core-shell nanoparticles is valid when just using peak intensities, but more detailed modeling is needed to describe the inelastic background.

  2. High Intensity Beam and X-Ray Converter Target Interactions and Mitigation

    Energy Technology Data Exchange (ETDEWEB)

    Chem, Y-J; McCarrick, J F; Guethlein, G; Chambers, F; Falabella, S; Lauer, E; Richardson, R; Weir, J

    2002-07-31

    Ions extracted from a solid surface or plasma by impact of an high intensity and high current electron beam can partially neutralize the beam space charge and change the focusing system. We have investigated ion emission computationally and experimentally. By matching PIC simulation results with available experimental data, our finding suggests that if a mix of ion species is available at the emitting surface, protons dominate the backstreaming ion effects, and that, unless there is surface flashover, ion emission is source limited. We have also investigated mitigation, such as e-beam cleaning, laser cleaning and ion trapping with a foil barrier. The temporal behavior of beam spot size with a foil barrier and a focusing scheme to improve foil barrier performance are discussed.

  3. Dynamics of hollow atom formation in intense x-ray pulses probed by partial covariance mapping.

    Science.gov (United States)

    Frasinski, L J; Zhaunerchyk, V; Mucke, M; Squibb, R J; Siano, M; Eland, J H D; Linusson, P; v d Meulen, P; Salén, P; Thomas, R D; Larsson, M; Foucar, L; Ullrich, J; Motomura, K; Mondal, S; Ueda, K; Osipov, T; Fang, L; Murphy, B F; Berrah, N; Bostedt, C; Bozek, J D; Schorb, S; Messerschmidt, M; Glownia, J M; Cryan, J P; Coffee, R N; Takahashi, O; Wada, S; Piancastelli, M N; Richter, R; Prince, K C; Feifel, R

    2013-08-16

    When exposed to ultraintense x-radiation sources such as free electron lasers (FELs) the innermost electronic shell can efficiently be emptied, creating a transient hollow atom or molecule. Understanding the femtosecond dynamics of such systems is fundamental to achieving atomic resolution in flash diffraction imaging of noncrystallized complex biological samples. We demonstrate the capacity of a correlation method called "partial covariance mapping" to probe the electron dynamics of neon atoms exposed to intense 8 fs pulses of 1062 eV photons. A complete picture of ionization processes competing in hollow atom formation and decay is visualized with unprecedented ease and the map reveals hitherto unobserved nonlinear sequences of photoionization and Auger events. The technique is particularly well suited to the high counting rate inherent in FEL experiments.

  4. Total X-Ray Scattering of Spider Dragline Silk

    Science.gov (United States)

    Benmore, C. J.; Izdebski, T.; Yarger, J. L.

    2012-04-01

    Total x-ray scattering measurements of spider dragline silk fibers from Nephila clavipes, Argiope aurantia, and Latrodectus hesperus all yield similar structure factors, with only small variations between the different species. Wide-angle x-ray scattering from fibers orientated perpendicular to the beam shows a high degree of anisotropy, and differential pair distribution functions obtained by integrating over wedges of the equatorial and meridian planes indicate that, on average, the majority (95%) of the atom-atom correlations do not extend beyond 1 nm. Futhermore, the atom-atom correlations between 1 and 3 nm are not associated with the most intense diffraction peaks at Q=1-2Å-1. Disordered molecular orientations along the fiber axis are consistent with proteins in similar structural arrangements to those in the equatorial plane, which may be associated with the silk’s greater flexibility in this direction.

  5. EDS measurements of X-ray intensity at WDS precision and accuracy using a silicon drift detector.

    Science.gov (United States)

    Ritchie, Nicholas W M; Newbury, Dale E; Davis, Jeffrey M

    2012-08-01

    The accuracy and precision of X-ray intensity measurements with a silicon drift detector (SDD) are compared with the same measurements performed on a wavelength dispersive spectrometer (WDS) for a variety of elements in a variety of materials. In cases of major (>0.10 mass fraction) and minor (>0.01 mass fraction) elements, the SDD is demonstrated to perform as well or better than the WDS. This is demonstrated both for simple cases in which the spectral peaks do not interfere (SRM-481, SRM-482, and SRM-479a), and for more difficult cases in which the spectral peaks have significant interferences (the Ba L/Ti K lines in a series of Ba/Ti glasses and minerals). We demonstrate that even in the case of significant interference high count SDD spectra are capable of accurately measuring Ti in glasses with Ba:Ti mass fraction ratios from 2.7:1 to 23.8:1. The results suggest that for many measurements wavelength spectrometry can be replaced with an SDD with improved accuracy and precision.

  6. 3D numerical modelling of the propagation of radiative intensity through a X-ray tomographied ligament

    Science.gov (United States)

    Le Hardy, David; Badri, Mohd Afeef; Rousseau, Benoit; Chupin, Sylvain; Rochais, Denis; Favennec, Yann

    2017-06-01

    In order to explain the macroscopic radiative behaviour of an open-cell ceramic foam, knowledge of its solid phase distribution in space and the radiative contributions by this solid phase is required. The solid phase in an open-cell ceramic foam is arranged as a porous skeleton, which is itself composed of an interconnected network of ligament. Typically, ligaments being based on the assembly of grains more or less compacted, exhibit an anisotropic geometry with a concave cross section having a lateral size of one hundred microns. Therefore, ligaments are likely to emit, absorb and scatter thermal radiation. This framework explains why experimental investigations at this scale must be developed to extract accurate homogenized radiative properties regardless the shape and size of ligaments. To support this development, a 3D numerical investigation of the radiative intensity propagation through a real world ligament, beforehand scanned by X-Ray micro-tomography, is presented in this paper. The Radiative Transfer Equation (RTE), applied to the resulting meshed volume, is solved by combining Discrete Ordinate Method (DOM) and Streamline upwind Petrov-Garlekin (SUPG) numerical scheme. A particular attention is paid to propose an improved discretization procedure (spatial and angular) based on ordinate parallelization with the aim to reach fast convergence. Towards the end of this article, we present the effects played by the local radiative properties of three ceramic materials (silicon carbide, alumina and zirconia), which are often used for designing open-cell refractory ceramic foams.

  7. The Intensity Modulation of the Fluorescent Line by a Finite Light Speed Effect in Accretion-powered X-Ray Pulsars

    Science.gov (United States)

    Yoshida, Yuki; Kitamoto, Shunji; Hoshino, Akio

    2017-11-01

    The X-ray line diagnostic method is a powerful tool for an investigation of plasma around accretion-powered X-ray pulsars. We point out an apparent intensity modulation of emission lines, with their rotation period of neutron stars, due to the finite speed of light (we call this effect the “finite light speed effect”) if the line emission mechanism is a kind of reprocessing, such as fluorescence or recombination after ionization by X-ray irradiation from pulsars. The modulation amplitude is determined by the size of the emission region, which is in competition with the smearing effect by the light crossing time in the emission region. This is efficient if the size of the emission region is roughly comparable to that of the rotation period multiplied by the speed of light. We apply this effect to a symbiotic X-ray pulsar, GX 1+4, where a spin modulation of the intense iron line of which has been reported. The finite light speed effect can explain the observed intensity modulation if its fluorescent region is the size of ˜ {10}12 cm.

  8. A simple X-ray emitter.

    Science.gov (United States)

    Murakami, Hiroaki; Ono, Ryoichi; Hirai, Atsuhiko; Hosokawa, Yoshinori; Kawai, Jun

    2005-07-01

    A compact X-ray emission instrument is made, and the X-ray spectra are measured by changing the applied electric potential. Strong soft X-rays are observed when evacuating roughly and applying a high voltage to an insulator settled in this device. The X-ray intensity is higher as the applied voltage is increased. A light-emitting phenomenon is observed when this device emits X-rays. The present X-ray emitter is made of a small cylinder with a radius of 20 mm and a height of 50 mm. This X-ray generator has a potential to be used as an X-ray source in an X-ray fluorescence spectrometer.

  9. Measurement of angular distributions of K x-ray intensity of Ti and Cu thick targets following impact of 10–25 keV electrons

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Bhupendra; Kumar, Sunil; Prajapati, Suman; Singh, Bhartendu K. [Atomic Physics Laboratory, Department of Physics, Institute of Science, Banaras Hindu University, Varanasi 221005 (India); Llovet, Xavier [Scientific and Technological Centers, Universitat de Barcelona, Lluís Solé i Sabarís 1-3, 08028 Barcelona (Spain); Shanker, R., E-mail: shankerorama@gmail.com [Atomic Physics Laboratory, Department of Physics, Institute of Science, Banaras Hindu University, Varanasi 221005 (India)

    2017-04-15

    Highlights: • New results on the angular distributions of relative intensities of K-X-rays lines of Ti and Cu thick targets under electron bombardment are reported. • An increase of relative intensity of Kα and Kβ X-ray lines has been found to be about 60–70% in the detection range θ = 105{sup 0}–165{sup 0}. • There is a slight impact energy dependence of Cu Kα X-ray line. • A reasonable agreement between experimental and PENELOPE MC Calculations are obtained. - Abstract: We present new results on angular distributions of the relative intensity of K{sub α} and K{sub β} x-ray lines of thick targets of Ti (Z = 22) and Cu (Z = 29) pure elements following impact of 10–25 keV electrons. The angular measurements of the K x-radiations were accomplished by rotating the target surface with respect to the electron beam direction. The x-rays emerging from the target surface in reflection mode were detected by an energy dispersive Si P-I-N photodiode detector. The resulting variation of the relative intensity of the characteristic lines as a function of angle of detection and impact energy has been found to be anisotropic and it is considered to arise due to change in path lengths at a given incidence angle α for the photons generated by direct as well as by indirect K shell ionization processes. The measured angular variations of relative intensity of K{sub α} and K{sub β} x-ray lines of both targets are found to increase by about 60–70% in going from θ = 105{sup 0} to 165{sup 0} at a given impact energy; however there is a slight indication of impact energy dependence of Cu K{sub α} x-ray line as also noted by the earlier workers. We compare the experimental results with those obtained by Monte Carlo simulations using PENELOPE calculations; the agreement between experiment and theory is found to be satisfactory within uncertainties involved in the measurements and the theoretical results.

  10. Joint x-ray

    Science.gov (United States)

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

  11. Relative intensities of gadolinium L X-rays, induced by proton bombardment at energies between 200 keV to 750 keV

    Energy Technology Data Exchange (ETDEWEB)

    Canto, C. E.; De Lucio, O. G.; Morales, J. G.; Pineda, J. C. [UNAM, Instituto de Fisica, Circuito Exterior, Ciudad Universitaria, 04510 Mexico D. F. (Mexico)

    2012-06-15

    Relative intensities of Gd characteristic L X-ray, induced by proton impact have been measured for GdF{sub 3} thin films, as a function of projectile energy and also as a function of a variable defined as the relative velocity of the incoming particle. Results are presented as intensity ratios for L sub-shells and intensity ratios for particular transitions both of them measured with respect to the total number of X-ray photons recorded; in all cases it is possible to show an energy dependence for these intensity ratios. Complementary microanalysis studies (Atomic force microscopy, Scanning electron microscopy/EDS) were performed in order to have accurate information on the chemical composition and surface properties of the thin films. (Author)

  12. Ultrashort x-ray pulse generation by nonlinear Thomson scattering of a relativistic electron with an intense circularly polarized laser pulse

    Directory of Open Access Journals (Sweden)

    F. Liu

    2012-07-01

    Full Text Available The nonlinear Thomson scattering of a relativistic electron with an intense laser pulse is calculated numerically. The results show that an ultrashort x-ray pulse can be generated by an electron with an initial energy of 5 MeV propagating across a circularly polarized laser pulse with a duration of 8 femtosecond and an intensity of about 1.1×10^{21}  W/cm^{2}, when the detection direction is perpendicular to the propagation directions of both the electron and the laser beam. The optimal values of the carrier-envelop phase and the intensity of the laser pulse for the generation of a single ultrashort x-ray pulse are obtained and verified by our calculations of the radiation characteristics.

  13. Generation of High-Power High-Intensity Short X-Ray Free-Electron-Laser Pulses.

    Science.gov (United States)

    Guetg, Marc W; Lutman, Alberto A; Ding, Yuantao; Maxwell, Timothy J; Decker, Franz-Josef; Bergmann, Uwe; Huang, Zhirong

    2018-01-05

    X-ray free-electron lasers combine a high pulse power, short pulse length, narrow bandwidth, and high degree of transverse coherence. Any increase in the photon pulse power, while shortening the pulse length, will further push the frontier on several key x-ray free-electron laser applications including single-molecule imaging and novel nonlinear x-ray methods. This Letter shows experimental results at the Linac Coherent Light Source raising its maximum power to more than 300% of the current limit while reducing the photon pulse length to 10 fs. This was achieved by minimizing residual transverse-longitudinal centroid beam offsets and beam yaw and by correcting the dispersion when operating over 6 kA peak current with a longitudinally shaped beam.

  14. Comparative study of scattered radiation levels from 80-kVp and 240-kVp x rays in the surgical intensive care unit

    Energy Technology Data Exchange (ETDEWEB)

    Herman, M.W.; Patrick, J.; Tabrisky, J.

    1980-11-01

    The levels of scattered radiation from 80-kVp and 240-kVp mobile x-ray units were measured in the surgical intensive care unit (ICU). The intensity of scatter of the 240-kVp x rays does not decrease with distance as rapidly as with the 80-kVp beam. In an ICU with four beds, the weekly radiation exposure at the nurses's station approximated 0.05 mR (0.13 x 10/sup -7/ C/kg) for the 80-kVp beam and 0.2 mR (0.52 x 10/sup -7/ C/kg) for the 240-kVp beam. Thus, the annual exposure from either unit would be well below the Maximum Permissible Exposure for nonoccupational workers.

  15. A new concept for conventional X-ray diagnostics in an intensive-care unit. Neues Konzept fuer die konventionelle Roentgendiagnostik in der Intensivmedizin

    Energy Technology Data Exchange (ETDEWEB)

    Grabbe, E.; Fischer, N.; Vosshenrich, R. (Goettingen Univ. (Germany, F.R.). Abt. fuer Roentgendiagnostik)

    1989-07-01

    A modified examination concept to improve conventional X-ray diagnostics in an intensive-care unit is presented. This planning is based on the development of new technical components in the field of mobile diagnostics and the availability of improved basic materials that can certainly promote such a project. This is presently being installed in the Clinical Centre of the University of Goettingen and will be subjected to a critical cost/efficiency analysis during a run of one year. (orig.).

  16. Proton therapy versus intensity modulated x-ray therapy in the treatment of prostate cancer: Estimating secondary cancer risks

    Science.gov (United States)

    Fontenot, Jonas David

    External beam radiation therapy is used to treat nearly half of the more than 200,000 new cases of prostate cancer diagnosed in the United States each year. During a radiation therapy treatment, healthy tissues in the path of the therapeutic beam are exposed to high doses. In addition, the whole body is exposed to a low-dose bath of unwanted scatter radiation from the pelvis and leakage radiation from the treatment unit. As a result, survivors of radiation therapy for prostate cancer face an elevated risk of developing a radiogenic second cancer. Recently, proton therapy has been shown to reduce the dose delivered by the therapeutic beam to normal tissues during treatment compared to intensity modulated x-ray therapy (IMXT, the current standard of care). However, the magnitude of stray radiation doses from proton therapy, and their impact on this incidence of radiogenic second cancers, was not known. The risk of a radiogenic second cancer following proton therapy for prostate cancer relative to IMXT was determined for 3 patients of large, median, and small anatomical stature. Doses delivered to healthy tissues from the therapeutic beam were obtained from treatment planning system calculations. Stray doses from IMXT were taken from the literature, while stray doses from proton therapy were simulated using a Monte Carlo model of a passive scattering treatment unit and an anthropomorphic phantom. Baseline risk models were taken from the Biological Effects of Ionizing Radiation VII report. A sensitivity analysis was conducted to characterize the uncertainty of risk calculations to uncertainties in the risk model, the relative biological effectiveness (RBE) of neutrons for carcinogenesis, and inter-patient anatomical variations. The risk projections revealed that proton therapy carries a lower risk for radiogenic second cancer incidence following prostate irradiation compared to IMXT. The sensitivity analysis revealed that the results of the risk analysis depended only

  17. Fragmentation Dynamics of Endohedral Fullerene Ho3N@C80 Ionized with Intense and Short X-Ray FEL Pulses

    Science.gov (United States)

    Murphy, Brendan; Xiong, Hui; Fang, Li; Osipov, Timur; Kukk, Edwin; Petrovic, Vladmir; Li, Heng; Sistrunk, Emily; Squibb, Richard; Feifel, Raimund; Ferguson, Kenneth; Krzywinski, Jacek; Sebastian, Sebastian; Guehr, Markus; Bostedt, Christoph; Bucksbaum, Philip; Berrah, Nora

    2015-05-01

    The photoionization and fragmentation dynamics of gas phase endohedral fullerenes Ho3N@C80 with intense femtosecond X-ray pulses from the Linac Coherent Light Source (LCLS) free electron laser (FEL) have been investigated. The central photon energy of the x-ray pulses was set at 1530 eV, targeting the absorption of the 3d electron on Ho. Multiphoton ionization led to the highest charge state observed on the parent molecule to be Ho3N@C805+ , suggesting a stable structure even with 5 charges on the parent molecule. We will present the different atomic and molecular fragments dynamics observed. This work is funded by the Department of Energy, Office of Science, Basic Energy Sciences, Division of Chemical Sciences, Geosciences and Biosciences under grant N. DE-FG02-92ER14299.A002 and in part by National Science Foundation under Grant No. 1404109.

  18. Chest X-Ray

    Medline Plus

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

  19. X-ray spectrometry using polycapillary X-ray optics and position sensitive detector.

    Science.gov (United States)

    Ding, X; Xie, J; He, Y; Pan, Q; Yan, Y

    2000-10-02

    Polycapillary X-ray optics (capillary X-ray lens) are now popular in X-ray fluorescence (XRF) analysis. Such an X-ray lens can collect X-rays emitted from an X-ray source in a large solid angle and form a very intense X-ray microbeam which is very convenient for microbeam X-ray fluorescence (MXRF) analysis giving low minimum detection limits (MDLs) in energy dispersive X-ray fluorescence (EDXRF). A new method called position sensitive X-ray spectrometry (PSXS) which combines an X-ray lens used to form an intense XRF source and a position sensitive detector (PSD) used for wavelength dispersive spectrometry (WDS) measurement was developed recently in the X-ray Optics Laboratory of Institute of Low Energy Nuclear Physics (ILENP) at Beijing Normal University. Such a method can give high energy and spacial resolution and high detection efficiency simultaneously. A short view of development of both the EDXRF using a capillary X-ray lens and the new PSXS is given in this paper.

  20. Hand x-ray

    Science.gov (United States)

    X-ray - hand ... A hand x-ray is taken in a hospital radiology department or your health care provider's office by an ... technician. You will be asked to place your hand on the x-ray table, and keep it ...

  1. X-Ray

    Science.gov (United States)

    ... show up on chest X-rays. Breast cancer. Mammography is a special type of X-ray test used to examine breast tissue. Enlarged heart. This sign of congestive heart failure shows up clearly on X-rays. Blocked blood vessels. Injecting a contrast material that contains iodine can help highlight sections ...

  2. Measurement of 2l-nl' x-ray transitions from approximately 1 microm Kr clusters irradiated by high-intensity femtosecond laser pulses.

    Science.gov (United States)

    Hansen, S B; Fournier, K B; Faenov, A Ya; Magunov, A I; Pikuz, T A; Skobelev, I Yu; Fukuda, Y; Akahane, Y; Aoyama, M; Inoue, N; Ueda, H; Yamakawa, K

    2005-01-01

    X-ray line emission from 2l-nl' transitions in Ne-like Kr and nearby ions has been observed from approximately 1 microm Kr clusters irradiated by fs-scale laser pulses at the JAERI facility in Kyoto, Japan. The incident laser intensity reached 10(19) W/cm2, with pulse energies from 50 to 300 mJ and pulse durations from 30 to 500 fs. The dependence of the x-ray spectral features and intensity on the incident laser intensity is rather weak, indicating that the 1-2 ps cluster lifetimes limit the number of ions beyond Ne-like Kr that can be produced by collisional ionization. Lines from F- to Al-like Kr emitted from the cluster plasmas have been identified using data from the relativistic multiconfiguration flexible atomic code. A collisional-radiative model based on these data has been constructed and used to determine that the cluster plasma has electron densities near 10(22) cm(-3), temperatures of a few hundred eV, and hot electron fractions of a few percent.

  3. Ward chest X-rays and extra-vascular lung water estimations in patients in intensive care

    Energy Technology Data Exchange (ETDEWEB)

    Haller, J.; Czembirek, H.; Salomonowitz, E.; Laggner, A.; Sommer, G.; Tscholakoff, D.; Leitner, H.; Kleinberger, G.

    1985-01-01

    Radiological staging of pulmonary oedema was compared with the determination of extra-vascular lung water by means of a double indicator dilution technique. One hundred and forty-six ward chest radiographs were evaluated and compared with the results of simultaneous measurements of lung water. Seventy-seven cases could be evaluated statistically. Chest x-rays regarded as normal corresponded to extra-vascular lung water of 5 to 9 ml./kg. body weight. Interstitial oedema (radiological stage I and II) correspond to extravascular lung water levels of 8 to 12 ml./kg. Differentiation of stages I and II was not possible. During stage III, extra-vascular lung water was 15 to 21 ml./kg. A comparative analysis of these findings revealed a discrepancy of 34%. The reasons for this are discussed.

  4. Sandia Mark II X-Ray System

    Energy Technology Data Exchange (ETDEWEB)

    Morrison, L.W.

    1979-11-01

    The Sandia Mark II X-Ray System was designed and developed to provide an intense source of mononergetic, ultra-soft x rays with energies between 0.282 and 1.486 keV. The x-ray tube design is similar to one developed by B.L. Henke and incorporates modifications made by Tom Ellsberry. An operations manual section is incorporated to help the experimenter/operator.

  5. X-ray spectroscopy of super-intense laser-produced plasmas for the study of nonlinear processes. Comparison with PIC simulations

    Science.gov (United States)

    Dalimier, E.; Faenov, A. Ya; Oks, E.; Angelo, P.; Pikuz, T. A.; Fukuda, Y.; Andreev, A.; Koga, J.; Sakaki, H.; Kotaki, H.; Pirozhkov, A.; Hayashi, Y.; Skobelev, I. Yu; Pikuz, S. A.; Kawachi, T.; Kando, M.; Kondo, K.; Zhidkov, A.; Tubman, E.; Butler, N. M. H.; Dance, R. J.; Alkhimova, M. A.; Booth, N.; Green, J.; Gregory, C.; McKenna, P.; Woolsey, N.; Kodama, R.

    2017-02-01

    We present X-ray spectroscopic diagnostics in femto-second laser-driven experiments revealing nonlinear phenomena caused by the strong coupling of the laser radiation with the created plasma. Among those nonlinear phenomena, we found the signatures of the Two Plasmon Decay (TPD) instability in a laser-driven CO2 cluster-based plasma by analyzing the Langmuir dips in the profile of the O VIII Lyε line, caused by the Langmuir waves created at the high laser intensity 3 1018Wcm-2. With similar laser intensities, we reveal also the nonlinear phenomenon of the Second Harmonic Generation (SHG) of the laser frequency by analyzing the nonlinear phenomenon of satellites of Lyman δ and ε lines of Ar XVII. In the case of relativistic laser-plasma interaction we discovered the Parametric Decay Instability (PDI)-induced ion acoustic turbulence produced simultaneously with Langmuir waves via irradiation of thin Si foils by laser intensities of 1021Wcm-2.

  6. X-Ray Polarimetry

    OpenAIRE

    Kaaret, Philip

    2014-01-01

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

  7. SU-E-T-503: Intensity Modulated Proton Therapy (IMPT) Versus Intensity Modulated X-Ray Therapy (IMRT) for Patient with Hepatocellular Carcinoma: A Dosimetric Comparison

    Energy Technology Data Exchange (ETDEWEB)

    Singh, H; Zhao, L; Prabhu, K; Rana, S; Zheng, Y [Procure Proton Therapy Center, Oklahoma City, OK (United States)

    2015-06-15

    Purpose This study compares the dosimetric parameters in treatment of unresectable hepatocellular carcinoma between intensity modulated proton therapy (IMPT) and intensity modulated x-ray radiation therapy (IMRT). Methods and Materials: We studied four patients treated at our institution. All patients were simulated supine with 4D-CT using a GE light speed simulator with a maximum slice thickness of 3mm. The average CT and an internal target volume to account for respiration motion were used for planning. Both IMRT and IMPT plans were created using Elekta’s CMSXiO treatment planning system (TPS). The prescription dose was 58.05 CGE in 15 fractions. The IMRT plans had five beams with combination of co-planar and non-co-planar. The IMPT plans had 2 to 3 beams. Dose comparison was performed based on the averaged results of the four patients. Results The mean dose and V95% to PTV were 58.24CGE, 98.57% for IMPT, versus 57.34CGE and 96.68% for IMRT, respectively. The V10, V20, V30 and mean dose of the normal liver for IMPT were 23.10%, 18.61%, 13.75% and 9.78 CGE; and 47.19%, 37.55%, 22.73% and 17.12CGE for IMRT. The spinal cord didn’t receive any dose in IMPT technique, but received a maximum of 18.77CGE for IMRT. The IMPT gave lower maximum dose to the stomach as compared to IMRT (19.26 vs 26.35CGE). V14 for left and right kidney was 0% and 2.32% for IMPT and 3.89% and 29.54% for IMRT. The mean dose, V35, V40 and V45 for small bowl were similar in both techniques, 0.74CGE, 6.27cc, 4.85cc and 3.53 cc for IMPT, 3.47CGE, 9.73cc, 7.61cc 5.35cc for IMRT. Conclusion Based on this study, IMPT plans gave less dose to the critical structures such as normal liver, kidney, stomach and spinal cord as compared to IMRT plans, potentially leading to less toxicity and providing better quality of life for patients.

  8. Low Energy X-Ray Diagnostics - 1981.

    Science.gov (United States)

    1981-01-01

    ray Analysis, 18, 26 (1975). practicA !ity of thermal recording of intense x-rays. 2. R.P. Godwin, Adv. in X-rays Analysis, 19, 533 Many optical...the 15. T. W. Barbee Jr., in "National Science Foundation behavior of LSM dispersion elements. - Twenty Sixth Annual Report for Fiscal Year Extension

  9. Chest X-Ray

    Medline Plus

    Full Text Available ... by Image/Video Gallery Your Radiologist Explains Chest X-ray Transcript Welcome to Radiology Info dot org! Hello, ... d like to talk with you about chest radiography also known as chest x-rays. Chest x- ...

  10. Chest X-Ray

    Medline Plus

    Full Text Available ... to consider the likelihood of benefit to your health. While a chest x-ray use a tiny dose of ionizing radiation, the benefit of an accurate diagnosis far outweighs any risk. For more information about chest x-rays, visit Radiology Info dot ...

  11. X-ray Observations at Gaisberg Tower

    Directory of Open Access Journals (Sweden)

    Pasan Hettiarachchi

    2018-01-01

    Full Text Available We report the occurrence of X-rays at ground level due to cloud-to-ground flashes of upward-initiated lightning from Gaisberg Tower, in Austria, which is located at an altitude of 1300 m. This is the first observation of X-ray emissions from upward lightning from a tower top located at high altitude. Measurements were carried out using scintillation detectors installed close to the tower top in two phases from 2011 to 2015. X-rays were recorded in three subsequent strokes of three flashes out of the total of 108 flashes recorded in the system during both phases. In contrast to the observations from downward natural or triggered lightning, X-rays were observed only within 10 µs before the subsequent return stroke. This shows that X-rays were emitted when the dart leader was in the vicinity of the tower top, hence during the most intense phase of the dart leader. Both the detected energy and the fluence of X-rays are far lower compared to X-rays from downward natural or rocket-triggered lightning. In addition to the above 108 flashes, an interesting observation of X-rays produced by a nearby downward flash is also presented. The shorter length of dart-leader channels in Gaisberg is suggested as a possible cause of this apparently weaker X-ray production.

  12. Survey of doses and frequency of X-ray examinations on children at the intensive care unit of a large reference pediatric hospital

    Energy Technology Data Exchange (ETDEWEB)

    Pedrosa de Azevedo, Ana Cecilia [Fundacao Oswaldo Cruz-FIOCRUZ, Escola Nacional de Saude Publica Sergio Arouca, Centro de Estudos da Saude do Trabalhador e Ecologia Humana-CESTEH, Rua Leopoldo Bulhoes 1480, Manguinhos 21041-210, Rio de Janeiro (Brazil)]. E-mail: acpa@ensp.fiocruz.br; Osibote, Adelaja Otolorin [Fundacao Oswaldo Cruz-FIOCRUZ, Escola Nacional de Saude Publica Sergio Arouca, Centro de Estudos da Saude do Trabalhador e Ecologia Humana-CESTEH, Rua Leopoldo Bulhoes 1480, Manguinhos 21041-210, Rio de Janeiro (Brazil); Bastos Boechat, Marcia Cristina [Instituto Fernandes Figueira, Fundacao Oswaldo Cruz-FIOCRUZ (Brazil)

    2006-12-15

    Objective: This work aims to evaluate the entrance surface dose (ESD), the body organ dose (BOD) and the effective dose (E) resulting from pediatric radiological procedures with the use of portable X-ray equipments. Materials and methods: The software DoseCal was used to evaluate the doses imparted to patients. The children were classified according to their weight and age groups, and the study included three sectors of the intensive care unit of a large reference pediatric hospital in Rio de Janeiro. Results: A total of 518 radiographs have been performed (424 for chest and 94 for abdomen). The statistical data were compared with previously published results. The BOD is presented for the most exposed organs. Conclusion: The mean value of ESD and E varied widely among neonates. The highest number of radiographs per infant peaked 33 for chest examination in the age group 0-1 year.

  13. 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.

  14. X-ray imaging

    Energy Technology Data Exchange (ETDEWEB)

    Fenster, A. [Univ. of Western Ontario, J.P. Robarts Institute, London, Ontario (Canada); Yaffe, M.J. [Univ. of Toronto, Depts. of Medical Biophysics and Medical Imaging, North York, Ontario (Canada)

    1995-09-01

    In this article, we briefly review the principles of x-ray imaging, consider some of its applications in medicine and describe some of the developments in this area which have taken place in Canada. X rays were first used for diagnosis and therapy in medicine almost immediately after the report of their discovery by Roentgen in 1895. X-ray imaging has remained the primary tool for the investigation of structures within the body up to the present time (Johns and Cunningham 1983). Medical x rays are produced in a vacuum tube by the electron bombardment of a metallic target. Electrons emitted from a heated cathode are accelerated through an electric field to energies of 20-150 keV (wavelength 6.2-0.83 nm) and strike a target anode. X rays appear in a spectrum of bremsstrahlung radiation with energies ranging from 0 to a value that is numerically equal to the peak voltage applied between the cathode and anode of the x-ray tube (Figure 1). In addition, where the energy of the impinging electrons exceeds the binding energy of inner atomic orbitals of the target material, electrons may be ejected from those shells. Filling of these shells by more loosely-bound electrons gives rise to x rays whose energies are equal to the difference of the binding energies of the donor and acceptor shells. The energies of these characteristic x rays are unique to the target material. Less than 1% of the energy of the incident electrons is converted to that of x rays, while the remainder is dissipated as heat in the target. For this reason, a tremendous amount of engineering has gone into the design of x-ray tubes that can yield a large fluence rate of quanta from a small effective source size, while withstanding the enormous applied heat loading (e.g. 10 kJ per exposure). Tungsten is by far the most common material used for targets in tubes for diagnostic radiology, because of its high melting point and its high atomic number; the efficiency of x-ray production is proportional to Z of the

  15. 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

  16. Bone X-Ray (Radiography)

    Medline Plus

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

  17. Bone X-Ray (Radiography)

    Medline Plus

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

  18. Abdomen X-Ray (Radiography)

    Science.gov (United States)

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

  19. Physical analysis of the shielding capacity for a lightweight apron designed for shielding low intensity scattering X-rays

    National Research Council Canada - National Science Library

    Kim, Seon Chil; Choi, Jeong Ryeol; Jeon, Byeong Kyou

    2016-01-01

    The purpose of this paper is to develop a lightweight apron that will be used for shielding low intensity radiation in medical imaging radiography room and to apply it to a custom-made effective shielding...

  20. Modifying effects of low-intensity extremely high-frequency electromagnetic radiation on content and composition of fatty acids in thymus of mice exposed to X-rays.

    Science.gov (United States)

    Gapeyev, Andrew B; Aripovsky, Alexander V; Kulagina, Tatiana P

    2015-03-01

    The effects of extremely high-frequency electromagnetic radiation (EHF EMR) on thymus weight and its fatty acids (FA) content and FA composition in X-irradiated mice were studied to test the involvement of FA in possible protective effects of EHF EMR against ionizing radiation. Mice were exposed to low-intensity pulse-modulated EHF EMR (42.2 GHz, 0.1 mW/cm(2), 20 min exposure, 1 Hz modulation) and/or X-rays at a dose of 4 Gy with different sequences of the treatments. In 4-5 hours, 10, 30, and 40 days after the last exposure, the thymuses were weighed; total FA content and FA composition of the thymuses were determined on days 1, 10, and 30 using a gas chromatography. It was shown that after X-irradiation of mice the total FA content per mg of thymic tissue was significantly increased in 4-5 h and decreased in 10 and 30 days after the treatment. On days 30 and 40 after X-irradiation, the thymus weight remained significantly reduced. The first and tenth days after X-rays injury independently of the presence and sequence of EHF EMR exposure were characterized by an increased content of polyunsaturated FA (PUFA) and a decreased content of monounsaturated FA (MUFA) with unchanged content of saturated FA (SFA). Exposure of mice to EHF EMR before or after X-irradiation prevented changes in the total FA content in thymic tissue, returned the summary content of PUFA and MUFA to the control level and decreased the summary content of SFA on the 30th day after the treatments, and promoted the restoration of the thymus weight of X-irradiated mice to the 40th day of the observations. Changes in the content and composition of PUFA in the early period after treatments as well as at the restoration of the thymus weight under the combined action of EHF EMR and X-rays indicate to an active participation of FA in the acceleration of post-radiation recovery of the thymus by EHF EMR exposure.

  1. Chest X-Ray

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    Full Text Available ... Imaging Costs Video: Abdominal Ultrasound Video: Pelvic Ultrasound Radiology and You Sponsored by Image/Video Gallery Your Radiologist Explains Chest X-ray Transcript Welcome to Radiology Info dot org! Hello, I’m Dr. Geoffrey ...

  2. Chest X-Ray

    Medline Plus

    Full Text Available ... Index A-Z Spotlight March is National Colorectal Cancer Awareness Month Recently posted: Carotid Intima-Media Thickness ... of lung conditions such as pneumonia, emphysema and cancer. A chest x-ray requires no special preparation. ...

  3. Chest X-Ray

    Medline Plus

    Full Text Available ... Site Index A-Z Spotlight February is American Heart Month Recently posted: Carotid Intima-Media Thickness Test ... x-ray is used to evaluate the lungs, heart and chest wall and may be used to ...

  4. Chest X-Ray

    Medline Plus

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

  5. 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 ...

  6. Chest X-Ray

    Medline Plus

    Full Text Available ... accurate diagnosis far outweighs any risk. For more information about chest x-rays, visit Radiology Info dot ... Inc. (RSNA). To help ensure current and accurate information, we do not permit copying but encourage linking ...

  7. Sinus x-ray

    Science.gov (United States)

    ... an infection and inflammation of the sinuses called sinusitis . A sinus x-ray is ordered when you have any of the following: Symptoms of sinusitis Other sinus disorders, such as a deviated septum ( ...

  8. Chest X-Ray

    Medline Plus

    Full Text Available ... Index A-Z Spotlight November is National Lung Cancer Awareness Month Recently posted: Carotid Intima-Media Thickness ... of lung conditions such as pneumonia, emphysema and cancer. A chest x-ray requires no special preparation. ...

  9. Chest X-Ray

    Medline Plus

    Full Text Available ... exams and use a very small dose of ionizing radiation to produce pictures of the inside of the ... chest x-ray use a tiny dose of ionizing radiation, the benefit of an accurate diagnosis far outweighs ...

  10. Chest X-Ray

    Medline Plus

    Full Text Available ... and You Take our survey Sponsored by Image/Video Gallery Your Radiologist Explains Chest X-ray Transcript ... Carotid Intima-Media Thickness Test Medical Imaging Costs Video: Abdominal Ultrasound Video: Pelvic Ultrasound Radiology and You ...

  11. X-ray

    Science.gov (United States)

    ... X-ray References Geleijns J, Tack D. Medical physics: radiation risks. In: Adam A, Dixon AK, Gillard ... Updated by: C. Benjamin Ma, MD, Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic ...

  12. Chest X-Ray

    Medline Plus

    Full Text Available ... and use a very small dose of ionizing radiation to produce pictures of the inside of the ... x-ray use a tiny dose of ionizing radiation, the benefit of an accurate diagnosis far outweighs ...

  13. Chest X-Ray

    Medline Plus

    Full Text Available ... Your Radiologist Explains Chest X-ray Transcript Welcome to Radiology Info dot org! Hello, I’m Dr. ... University in Durham, North Carolina. I’d like to talk with you about chest radiography also known ...

  14. Chest X-Ray

    Medline Plus

    Full Text Available ... Index A-Z Spotlight October is National Breast Cancer Awareness Month Recently posted: Carotid Intima-Media Thickness ... of lung conditions such as pneumonia, emphysema and cancer. A chest x-ray requires no special preparation. ...

  15. 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 ...

  16. Bone X-Ray (Radiography)

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    Full Text Available ... ray examination. X-rays usually have no side effects in the typical diagnostic range for this exam. ... x-rays. A Word About Minimizing Radiation Exposure Special care is taken during x-ray examinations to ...

  17. Bone X-Ray (Radiography)

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    Full Text Available ... position possible that still ensures x-ray image quality. top of page Who interprets the results and ... standards used by radiology professionals. Modern x-ray systems have very controlled x-ray beams and dose ...

  18. Bone X-Ray (Radiography)

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

  19. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... ray examination. X-rays usually have no side effects in the typical diagnostic range for this exam. ... Media Arthritis X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety Images related to X-ray (Radiography) - ...

  20. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... of knee x-rays. A portable x-ray machine is a compact apparatus that can be taken ... of the body being examined, an x-ray machine produces a small burst of radiation that passes ...

  1. 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 ...

  2. Ionization of atomic hydrogen by an intense x-ray laser pulse: An ab initio study of the breakdown of the dipole approximation

    Science.gov (United States)

    Moe, Thore Espedal; Førre, Morten

    2018-01-01

    Solving the time-dependent Schrödinger equation numerically within the framework of an ab initio model, the breakdown of the dipole approximation in modeling the ionization and excitation dynamics of a hydrogen atom exposed to an intense 1.36-keV x-ray laser pulse is investigated in some detail. The relative importance of the A2 diamagnetic term in comparison with the A .p contribution to the resulting beyond-dipole (nondipole) light-matter interaction is studied for laser pulse intensities ranging from the weak perturbative to the strong-field regime. It is found that the diamagnetic interaction represents by far the most important correction to the dipole approximation at higher field strengths, while nondipole corrections induced by the A .p operator are generally small and largely independent of the laser intensity. The most profound finding of the present study was the discovery of a forward-backward asymmetry in the underlying electron ejection dynamics: Depending on the electron's kinetic energy in the final state, the photoelectron tends to be emitted in the laser propagation (forward) and/or counterpropagation (backward) directions, for energies corresponding to the low-energy and/or high-energy side of the multiphoton resonances, respectively.

  3. Reabsorption of soft x-ray emission at high x-ray free-electron laser fluences.

    Science.gov (United States)

    Schreck, Simon; Beye, Martin; Sellberg, Jonas A; McQueen, Trevor; Laksmono, Hartawan; Kennedy, Brian; Eckert, Sebastian; Schlesinger, Daniel; Nordlund, Dennis; Ogasawara, Hirohito; Sierra, Raymond G; Segtnan, Vegard H; Kubicek, Katharina; Schlotter, William F; Dakovski, Georgi L; Moeller, Stefan P; Bergmann, Uwe; Techert, Simone; Pettersson, Lars G M; Wernet, Philippe; Bogan, Michael J; Harada, Yoshihisa; Nilsson, Anders; Föhlisch, Alexander

    2014-10-10

    We report on oxygen K-edge soft x-ray emission spectroscopy from a liquid water jet at the Linac Coherent Light Source. We observe significant changes in the spectral content when tuning over a wide range of incident x-ray fluences. In addition the total emission yield decreases at high fluences. These modifications result from reabsorption of x-ray emission by valence-excited molecules generated by the Auger cascade. Our observations have major implications for future x-ray emission studies at intense x-ray sources. We highlight the importance of the x-ray pulse length with respect to the core-hole lifetime.

  4. X-Ray Absorption with Transmission X-Ray Microscopes

    NARCIS (Netherlands)

    de Groot, F.M.F.|info:eu-repo/dai/nl/08747610X

    2016-01-01

    In this section we focus on the use of transmission X-ray microscopy (TXM) to measure the XAS spectra. In the last decade a range of soft X-ray and hard X-ray TXM microscopes have been developed, allowing the measurement of XAS spectra with 10–100 nm resolution. In the hard X-ray range the TXM

  5. Automatic abdominal lymph node detection method based on local intensity structure analysis from 3D x-ray CT images

    Science.gov (United States)

    Nakamura, Yoshihiko; Nimura, Yukitaka; Kitasaka, Takayuki; Mizuno, Shinji; Furukawa, Kazuhiro; Goto, Hidemi; Fujiwara, Michitaka; Misawa, Kazunari; Ito, Masaaki; Nawano, Shigeru; Mori, Kensaku

    2013-03-01

    This paper presents an automated method of abdominal lymph node detection to aid the preoperative diagnosis of abdominal cancer surgery. In abdominal cancer surgery, surgeons must resect not only tumors and metastases but also lymph nodes that might have a metastasis. This procedure is called lymphadenectomy or lymph node dissection. Insufficient lymphadenectomy carries a high risk for relapse. However, excessive resection decreases a patient's quality of life. Therefore, it is important to identify the location and the structure of lymph nodes to make a suitable surgical plan. The proposed method consists of candidate lymph node detection and false positive reduction. Candidate lymph nodes are detected using a multi-scale blob-like enhancement filter based on local intensity structure analysis. To reduce false positives, the proposed method uses a classifier based on support vector machine with the texture and shape information. The experimental results reveal that it detects 70.5% of the lymph nodes with 13.0 false positives per case.

  6. Soft x-ray intensity profile measurements of electron cyclotron heated plasmas using semiconductor detector arrays in GAMMA 10 tandem mirror

    Energy Technology Data Exchange (ETDEWEB)

    Minami, R., E-mail: minami@prc.tsukuba.ac.jp; Imai, T.; Kariya, T.; Numakura, T.; Eguchi, T.; Kawarasaki, R.; Nakazawa, K.; Kato, T.; Sato, F.; Nanzai, H.; Uehara, M.; Endo, Y.; Ichimura, M. [Plasma Research Center, University of Tsukuba, Tsukuba, Ibaraki 305-8577 (Japan)

    2014-11-15

    Temporally and spatially resolved soft x-ray analyses of electron cyclotron heated plasmas are carried out by using semiconductor detector arrays in the GAMMA 10 tandem mirror. The detector array has 16-channel for the measurements of plasma x-ray profiles so as to make x-ray tomographic reconstructions. The characteristics of the detector array make it possible to obtain spatially resolved plasma electron temperatures down to a few tens eV and investigate various magnetohydrodynamic activities. High power electron cyclotron heating experiment for the central-cell region in GAMMA 10 has been started in order to reduce the electron drag by increasing the electron temperature.

  7. Subluminous X-ray binaries

    NARCIS (Netherlands)

    Armas Padilla, M.

    2013-01-01

    The discovery of the first X-ray binary, Scorpius X-1, by Giacconi et al. (1962), marked the birth of X-ray astronomy. Following that discovery, many additional X-ray sources where found with the first generation of X-ray rockets and observatories (e.g., UHURU and Einstein). The short-timescale

  8. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... the limitations of Bone X-ray (Radiography)? What is Bone X-ray (Radiography)? An x-ray (radiograph) ... top of page What are some common uses of the procedure? A bone x-ray is used ...

  9. Lumbosacral spine x-ray

    Science.gov (United States)

    X-ray - lumbosacral spine; X-ray - lower spine ... be placed over the lower part of your spine. You will be asked to hold your breath ... x-ray. The most common reason for lumbosacral spine x-ray is to look for the cause ...

  10. Experimental X-Ray Ghost Imaging.

    Science.gov (United States)

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

    2016-09-09

    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.

  11. 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.

  12. Chest X-Ray

    Medline Plus

    Full Text Available ... of ionizing radiation, the benefit of an accurate diagnosis far outweighs any risk. For more information about chest x-rays, visit Radiology Info dot org. Thank you for your time! Spotlight November is National Lung Cancer Awareness Month Recently posted: Carotid Intima-Media Thickness ...

  13. Chest X-Ray

    Medline Plus

    Full Text Available ... Screening/Wellness Disease/Condition Safety En Español More Info Images/Videos About Us News Physician Resources Professions ... Explains Chest X-ray Transcript Welcome to Radiology Info dot org! Hello, I’m Dr. Geoffrey Rubin, ...

  14. Pelvis x-ray

    Science.gov (United States)

    The x-ray is used to look for: Fractures Tumors Degenerative conditions of bones in the hips, pelvis, and upper legs ... Abnormal results may suggest: Pelvic fractures Arthritis of the hip joint ... spondylitis (abnormal stiffness of the spine and joint) ...

  15. Chest X-Ray

    Medline Plus

    Full Text Available ... Radiology (IDoR) Radiology and You Sponsored by Image/Video Gallery Your Radiologist Explains Chest X-ray Transcript ... Carotid Intima-Media Thickness Test Medical Imaging Costs Video: Abdominal Ultrasound Video: Pelvic Ultrasound November 8 is ...

  16. Response measurement of single-crystal chemical vapor deposition diamond radiation detector for intense X-rays aiming at neutron bang-time and neutron burn-history measurement on an inertial confinement fusion with fast ignition.

    Science.gov (United States)

    Shimaoka, T; Kaneko, J H; Arikawa, Y; Isobe, M; Sato, Y; Tsubota, M; Nagai, T; Kojima, S; Abe, Y; Sakata, S; Fujioka, S; Nakai, M; Shiraga, H; Azechi, H; Chayahara, A; Umezawa, H; Shikata, S

    2015-05-01

    A neutron bang time and burn history monitor in inertial confinement fusion with fast ignition are necessary for plasma diagnostics. In the FIREX project, however, no detector attained those capabilities because high-intensity X-rays accompanied fast electrons used for plasma heating. To solve this problem, single-crystal CVD diamond was grown and fabricated into a radiation detector. The detector, which had excellent charge transportation property, was tested to obtain a response function for intense X-rays. The applicability for neutron bang time and burn history monitor was verified experimentally. Charge collection efficiency of 99.5% ± 0.8% and 97.1% ± 1.4% for holes and electrons were obtained using 5.486 MeV alpha particles. The drift velocity at electric field which saturates charge collection efficiency was 1.1 ± 0.4 × 10(7) cm/s and 1.0 ± 0.3 × 10(7) cm/s for holes and electrons. Fast response of several ns pulse width for intense X-ray was obtained at the GEKKO XII experiment, which is sufficiently fast for ToF measurements to obtain a neutron signal separately from X-rays. Based on these results, we confirmed that the single-crystal CVD diamond detector obtained neutron signal with good S/N under ion temperature 0.5-1 keV and neutron yield of more than 10(9) neutrons/shot.

  17. 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.

  18. 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

  19. X-ray filter for x-ray powder diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Sinsheimer, John Jay; Conley, Raymond P.; Bouet, Nathalie C. D.; Dooryhee, Eric; Ghose, Sanjit

    2018-01-23

    Technologies are described for apparatus, methods and systems effective for filtering. The filters may comprise a first plate. The first plate may include an x-ray absorbing material and walls defining first slits. The first slits may include arc shaped openings through the first plate. The walls of the first plate may be configured to absorb at least some of first x-rays when the first x-rays are incident on the x-ray absorbing material, and to output second x-rays. The filters may comprise a second plate spaced from the first plate. The second plate may include the x-ray absorbing material and walls defining second slits. The second slits may include arc shaped openings through the second plate. The walls of the second plate may be configured to absorb at least some of second x-rays and to output third x-rays.

  20. 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...

  1. Radiation exposure and radiation risk of chest X-rays performed on an intensive care unit; Strahlenexposition und Strahlenrisiko von Roentgen-Thorax-Aufnahmen auf der Intensivstation

    Energy Technology Data Exchange (ETDEWEB)

    Keske, U.; Hierholzer, J.; Ehrenstein, T.; Zippler, A.; Hidajat, N.; Paust, E.; Cordes, M.; Matschke, S.; Felix, R. [Strahlenklinik und Poliklinik, Virchow-Klinikum, Medizinische Fakultaet, Humboldt Universitaet, Berlin (Germany); Pappert, D. [Abt. fuer Anaesthesie und Operative Intensivmedizin, Virchow-Klinikum, Medizinische Fakultaet, Humboldt Universitaet, Berlin (Germany)

    1996-12-31

    Aim of this study was to evaluate the radiation exposure of chest X-rays (CXR) performed on an intensive care unit (ICU) and quantify the resulting radiation risk. Data of 44 patients from an ICU were analyzed. An average of 52 CXRs were performed per patient. With the help of conversion factor charts based on a mathematical human phantom, organ doses were calculated for every patient. Effective dose (E) was calculated with the weighting factors of the ICRP 60. The resulting, age-corrected loss of life expectancy (LLE) was calculated. The average effective dose was 0.053 mSv for a single CXR and 2.73 mSv for all CXRs per patient. The average LLE was 0.026 days per CXR and 1.45 days for all CXRs per patient. It is concluded that radiation exposure and radiation risk of daily CXRs on an ICU are low and neglectable in most clinical situations. (orig.) [Deutsch] Ziel dieser Studie war es, die Strahlenexposition und das Strahlenrisiko von auf einer Intensivstation durchgefuehrten Roentgen-Thorax-Aufnahmen abzuschaetzen. Daten von 44 Intensivstations-Patienten wurden analysiert. Durchschnittlich wurden 52 Aufnahmen pro Patient angefertigt. Mit Hilfe von Konversionsfaktor-Tabellen, welche auf einem mathematischen menschlichen Phantom basieren, wurden fuer jeden Patienten die Organdosen ermittelt und daraus mit den Wichtungsfaktoren der ICRP 60 die effektive Dosis (E) berechnet. Das daraus resultierende durchschnittliche, bezueglich des Patientenalters korrigierte Lebenszeitrisiko (LZV{sub 0}) wurde kalkuliert. Die effektive Dosis betrug durchschnittlich 0,053 mSv pro Aufnahme und 2,73 mSv fuer alle Aufnahmen eines Patienten. Der Lebenszeitverlust betrug durschnittlich 0,026 Tage pro Aufnahme und 1,45 Tage fuer alle Aufnahmen eines Patienten. Die Strahlenexposition und auch das Strahlenrisiko von taeglich durchgefuehrten Roentgen-Thorax-Aufnahmen auf Intensivstationen ist somit als gering einzuschaetzen und duerfte in den meisten klinischen Situationen zu vernachlaessigen

  2. XMM-Newton X-Ray Observation of Jupiter

    Science.gov (United States)

    Waite, J. Hunter

    2005-01-01

    Soft X-ray emission has been observed from the disk of both Jupiter and Saturn as well as from the auroral regions of these planets. The low-latitude disk emission as observed by ROSAT, the Chandra X-Ray Observatory, and XMM-Newton appears to be uniformly distributed across the disk and to be correlated with solar activity. These characteristics suggest that the disk x-rays are produced by: (1) the elastic scattering of solar X-rays by atmospheric neutrals and (2) the absorption of solar X-rays in the carbon K-shell followed by fluorescent emission. The carbon atoms are found in methane molecules located below the homopause. In this paper we present the results of calculations of the scattering albedo for soft x-rays. We also show the calculated x-ray intensity for a range of atmospheric abundances for Jupiter and Saturn and for a number of solar irradiance spectra. The model calculations are compared with recent x-ray observations of Jupiter and Saturn. We conclude that the emission of soft x-rays from the disks of Jupiter and Saturn can be largely explained by the scattering and fluorescence of soft x-rays. We suggest that measured x-ray intensities from the disk regions of Jupiter

  3. Bone X-Ray (Radiography)

    Medline Plus

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

  4. Bone X-Ray (Radiography)

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

  5. Bone X-Ray (Radiography)

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    Full Text Available ... shades of gray and air appears black. Until recently, x-ray images were maintained on large film ... assist you in finding the most comfortable position possible that still ensures x-ray image quality. top ...

  6. Bone X-Ray (Radiography)

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    Full Text Available ... conditions. Imaging with x-rays involves exposing a part of the body to a small dose of ... body. Once it is carefully aimed at the part of the body being examined, an x-ray ...

  7. Coherent x-ray optics

    CERN Document Server

    Paganin, David M

    2006-01-01

    'Coherent X-Ray Optics' gives a thorough treatment of the rapidly expanding field of coherent x-ray optics, which has recently experienced something of a renaissance with the availability of third-generation synchrotron sources.

  8. Bone X-Ray (Radiography)

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    Full Text Available ... patient. top of page How does the procedure work? X-rays are a form of radiation like ... Safety page for more information about radiation dose. Women should always inform their physician or x-ray ...

  9. Bone X-Ray (Radiography)

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    Full Text Available ... tissues around or in bones. top of page How should I prepare? Most bone x-rays require ... is placed beneath the patient. top of page How does the procedure work? X-rays are a ...

  10. Bone X-Ray (Radiography)

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    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 ( ...

  11. Bone X-Ray (Radiography)

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    Full Text Available ... standards used by radiology professionals. Modern x-ray systems have very controlled x-ray beams and dose ... and procedures may vary by geographic region. Discuss the fees associated with your prescribed ...

  12. Bone X-Ray (Radiography)

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    Full Text Available ... current x-ray images for diagnosis and disease management. top of page How is the procedure performed? ... have very controlled x-ray beams and dose control methods to minimize stray (scatter) radiation. This ensures ...

  13. Bone X-Ray (Radiography)

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    Full Text Available ... pregnancy and x-rays. top of page What does the equipment look like? The equipment typically used ... placed beneath the patient. top of page How does the procedure work? X-rays are a form ...

  14. Bone X-Ray (Radiography)

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    Full Text Available ... of ionizing radiation to produce pictures of the inside of the body. X-rays are the oldest ... have very controlled x-ray beams and dose control methods to minimize stray (scatter) radiation. This ensures ...

  15. Bone X-Ray (Radiography)

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    Full Text Available ... that might interfere with the x-ray images. Women should always inform their physician and x-ray technologist if there is any possibility that they are pregnant. Many imaging tests are not performed during pregnancy ...

  16. Bone X-Ray (Radiography)

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

  17. Bone X-Ray (Radiography)

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    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 ...

  18. Bone X-Ray (Radiography)

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    Full Text Available ... standards used by radiology professionals. Modern x-ray systems have very controlled x-ray beams and dose control methods to minimize stray (scatter) radiation. This ensures ...

  19. Bone X-Ray (Radiography)

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    Full Text Available ... tissue shows up in shades of gray and air appears black. Until recently, x-ray images were ... position possible that still ensures x-ray image quality. top of page Who interprets the results and ...

  20. Bone X-Ray (Radiography)

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    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 ...

  1. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... be taken to minimize radiation exposure to the baby. See the Safety page for more information about pregnancy and x-rays. top of page What does the equipment look like? The equipment typically used for bone x-rays consists of an x-ray tube suspended over a table on which the patient ...

  2. Bone X-Ray (Radiography)

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

  3. X-Ray Exam: Forearm

    Science.gov (United States)

    ... recorded on a computer or special X-ray film. This image shows the soft tissues and bones of the forearm. The X-ray image is black and white. Dense structures that block the passage of the X-ray beam through the body, such as the bones, appear white on the ...

  4. Characteristics of specifications of transportable inverter-type X-ray equipment

    CERN Document Server

    Yamamoto, K; Asano, H

    2003-01-01

    Our X-ray systems study group measured and examined the characteristics of four transportable inverter-type X-ray equipments. X-ray tube voltage and X-ray tube current were measured with the X-ray tube voltage and the X-ray tube current measurement terminals provided with the equipment. X-ray tube voltage, irradiation time, and dose were measured with a non-invasive X-ray tube voltage-measuring device, and X-ray output was measured by fluorescence meter. The items investigated were the reproducibility and linearity of X-ray output, error of pre-set X-ray tube voltage and X-ray tube current, and X-ray tube voltage ripple percentage. The waveforms of X-ray tube voltage, the X-ray tube current, and fluorescence intensity draw were analyzed using the oscilloscope gram and a personal computer. All of the equipment had a preset error of X-ray tube voltage and X-ray tube current that met Japanese Industrial Standards (JIS) standards. The X-ray tube voltage ripple percentage of each equipment conformed to the tendenc...

  5. 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.

  6. Equatorial Spread F Development/Disruption under Disturbance Electric Fields during Some Recent Intense Magnetic Storms.

    Science.gov (United States)

    Abdu, M. A.; Paula, E. R.; Batista, I. S.; Reinisch, B. W.; Denardini, C. M.; Sobral, J. H.

    2006-05-01

    Equatorial spread F (ESF) and associated plasma bubble irregularity development can be initiated or inhibited under disturbance electric fields associated with magnetic storms. Case studies of ESF intensification/inhibition under intense storm conditions are rare, however. We have addressed this question using the data collected from the Brazilian network of Digisondes, a VHF radar and GPS scintillation receivers, complemented by Digisonde data from Jicamarca and satellite born measurements. Dawn-dusk electric fields penetrating to equatorial latitude in the early phase of a storm event cause disruption of ESF development under a nightside westward electric field, that causes a rapid descent of the F layer. Large intensity prompt penetration electric fields occurring on the evening/post sunset ionosphere cause rapid uplifts of the F layer, and existing ESF patch structures seen by the radar to move to higher altitudes often exceeding the limits of the instruments (>1300 km) so that possible generation of irregularities by disturbance electric fields can only be detected by scintillation receivers. Disturbance dynamo electric fields are found to strongly influence the ESF development, which is inhibited during post sunset hours while subject to intensification during post midnight hours. The possible role of a disturbance trans-equatorial wind in suppressing the ESF generation is also examined

  7. Ultrafast x-ray-induced nuclear dynamics in diatomic molecules using femtosecond x-ray-pump–x-ray-probe spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Lehmann, C. S.; Picón, A.; Bostedt, C.; Rudenko, A.; Marinelli, A.; Moonshiram, D.; Osipov, T.; Rolles, D.; Berrah, N.; Bomme, C.; Bucher, M.; Doumy, G.; Erk, B.; Ferguson, K. R.; Gorkhover, T.; Ho, P. J.; Kanter, E. P.; Krässig, B.; Krzywinski, J.; Lutman, A. A.; March, A. M.; Ray, D.; Young, L.; Pratt, S. T.; Southworth, S. H.

    2016-07-01

    The availability at x-ray free electron lasers of generating two intense, femtosecond x-ray pulses with controlled time delay opens the possibility of performing time-resolved experiments for x-ray induced phenomena. We have applied this capability to molecular dynamics. In diatomic molecules composed of low-Z elements, K-shell ionization creates a core-hole state in which the main decay is an Auger process involving two electrons in the valence shell. After Auger decay, the nuclear wavepackets of the transient two-valence-hole states continue evolving on the femtosecond timescale, leading either to separated atomic ions or long-lived quasi-bound states. By using an x-ray pump and an x-ray probe pulse tuned above the K-shell ionization threshold of the nitrogen molecule, we are able to observe ion dissociation in progress by measuring the time-dependent kinetic energy releases of different breakup channels. We simulated the measurements on N2 with a molecular dynamics model that accounts for K-shell ionization, Auger decay, and time evolution of the nuclear wavepackets. In addition to explaining the time-dependent feature in the measured kinetic energy release distributions from the dissociative states, the simulation also reveals the contributions of quasi-bound states.

  8. Interaction of super intense laser pulses with thin foil: Dopler transformation of coherent light into X-ray and gamma-ray bands

    OpenAIRE

    Cherepenin, Vladimir A.; Kulagin, Victor V.

    2001-01-01

    The formation of relativistic electron mirror produced via ionization of thin solid target by ultraintense femtosecond laser pulse is considered with the help of computer simulations. It is shown that the reflection of weak counter-propagating wave from such a mirror can produce the coherent radiation in X-ray and gamma-ray bands. The spectrum of up-conversed radiation is investigated.

  9. A declaration of independence for Mg/Si. [Al/Si intensity ratio predictive usefulness for Mg/Si intensity ratio in lunar X-ray fluorescence

    Science.gov (United States)

    Hubbard, N.; Keith, J. E.

    1978-01-01

    The weak covariation that exists between Al/Si and Mg/Si for large areas of the lunar surface is little, if any, stronger than that forced on a random set of numbers that are subject to closure. The Mg and Al variations implied by the Mg/Si and Al/Si intensity ratio data are qualitatively like those seen in lunar soil sample data. Two petrogenetic provinces are suggested for terra materials; one appears to have 50% higher Mg values than the other. Using the improved data, Mg/Si variations can be studied at a signal-to-noise ratio greater than 5/1.

  10. Simultaneous high speed digital cinematographic and X-ray radiographic imaging of a intense multi-fluid interaction with rapid phase changes

    Energy Technology Data Exchange (ETDEWEB)

    Hansson, Roberta Concilio; Park, Hyun Sun; Dinh, Truc-Nam [Royal Institute of Technology, Division of Nuclear Power Safety, AlbaNova, Stockholm SE-106 91 (Sweden)

    2009-04-15

    As typical for the study of the vapor explosions, the qualitative and quantitative understanding of the phenomena requires visualization of both material and interface dynamics. A new approach to multi-fluid multiphase visualization is presented with the focus on the development of a synchronized high-speed visualization by digital cinematography and X-ray radiography. The developed system, named SHARP (simultaneous high-speed acquisition of X-ray radiography and photography), and its image processing methodology, directed to an image synchronization procedure and a separate quantification of vapor and molten material dynamics, is presented in this paper. Furthermore, we exploit an intrinsic property of the X-ray radiation, namely the differences in linear mass attenuation coefficients over the beam path through a multi-component system, to characterize the evolution of molten material distribution. Analysis of the data obtained by the SHARP system and image processing procedure developed granted new insights into the physics of the vapor explosion phenomena, as well as, quantitative information of the associated dynamic micro-interactions. (author)

  11. Generation of circularly polarized XUV and soft-x-ray high-order harmonics by homonuclear and heteronuclear diatomic molecules subject to bichromatic counter-rotating circularly polarized intense laser fields

    Science.gov (United States)

    Heslar, John; Telnov, Dmitry A.; Chu, Shih-I.

    2017-12-01

    Recently, studies of bright circularly polarized high-harmonic beams from atoms in the soft-x-ray region as a source for x-ray magnetic circular dichroism measurement in a tabletop-scale setup have received considerable attention. In this paper, we address the problem with molecular targets and perform a detailed quantum study of H2 +, CO, and N2 molecules in bichromatic counter-rotating circularly polarized laser fields where we adopt wavelengths (1300 and 790 nm) and intensities (2 ×1014W /cm2 ) reported in a recent experiment [Proc. Natl. Acad. Sci. USA 112, 14206 (2015), 10.1073/pnas.1519666112]. Our treatment of multiphoton processes in homonuclear and heteronuclear diatomic molecules is nonperturbative and based on the time-dependent density-functional theory for multielectron systems. The calculated radiation spectrum contains doublets of left and right circularly polarized harmonics with high-energy photons in the XUV and soft-x-ray ranges. Our results reveal intriguing and substantially different nonlinear optical responses for homonuclear and heteronuclear diatomic molecules subject to circularly polarized intense laser fields. We study in detail the below- and above-threshold harmonic regions and analyze the ellipticity and phase of the generated harmonic peaks.

  12. Hard X-ray Laue monochromator

    Science.gov (United States)

    Kocharyan, V. R.; Gogolev, A. S.; Kiziridi, A. A.; Batranin, A. V.; Muradyan, T. R.

    2016-06-01

    Experimental studies of X-ray diffraction from reflecting atomic planes (10¯11) of X-cut quartz single crystal in Laue geometry influenced by the temperature gradient were carried out. It is shown that by using the temperature gradient it is possible to reflect a hard X- ray beam with photon energy near the 100 keV with high efficiency. It has been experimentally proved that the intensity of the reflected beam can be increased by more than order depending on the value of the temperature gradient.

  13. 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.

  14. 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.

  15. X-ray optics of tapered capillaries.

    Science.gov (United States)

    Balaic, D X; Nugent, K A

    1995-11-01

    The optics of x-ray concentration by tapered glass capillaries is analyzed in terms of a phase-space construction describing their transmission efficiency. The parameters defining the intensity gain are given in terms of parameters describing the x-ray source used, the capillary taper profile, and glass characteristics. We introduce some key concepts in understanding these devices: the extreme ray and a phase-space description of sources and optics. They are used to develop an analytical formulation for the optimum gain characteristics of generalized tapers for use with synchrotrons and other low-divergence sources. This general solution is solved further for the case of conical taper profile. The predictions of this theory are compared with the results of three-dimensional, ray-tracing simulations of x-ray concentration efficiency for conical and paraboloidal tapers.

  16. 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.

  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. 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.

  19. Subgroup report on hard x-ray microprobes

    Energy Technology Data Exchange (ETDEWEB)

    Ice, G.E. [Oak Ridge National Lab., TN (United States); Barbee, T.; Bionta, R. [Lawrence Livermore National Lab., CA (United States); Howells, M.; Thompson, A.C. [Lawrence Berkeley Lab., CA (United States); Yun, W. [Argonne National Lab., IL (United States)

    1994-09-01

    The increasing availability of synchrotron x-ray sources has stimulated the development of advanced hard x-ray (E{>=}5 keV) microprobes. New x-ray optics have been demonstrated which show promise for achieving intense submicron hard x-ray probes. These probes will be used for extraordinary elemental detection by x-ray fluorescence/absorption and for microdiffraction to identify phase and strain. The inherent elemental and crystallographic sensitivity of an x-ray microprobe and its inherently nondestructive and penetrating nature makes the development of an advanced hard x-ray microprobe an important national goal. In this workshop state-of-the-art hard x-ray microprobe optics were described and future directions were discussed. Gene Ice, Oak Ridge National Laboratory (ORNL), presented an overview of the current status of hard x-ray microprobe optics and described the use of crystal spectrometers to improve minimum detectable limits in fluorescent microprobe experiments. Al Thompson, Lawrence Berkeley Laboratory (LBL), described work at the Center for X-ray Optics to develop a hard x-ray microprobe based on Kirkpatrick-Baez (KB) optics. Al Thompson also showed the results of some experimental measurements with their KB optics. Malcolm Howells presented a method for bending elliptical mirrors and Troy Barbee commented on the use of graded d spacings to achieve highest efficiency in KB multilayer microfocusing. Richard Bionta, Lawrence Livermore National Laboratory (LLNL), described the development of the first hard x-ray zone plates and future promise of so called {open_quotes}jelly roll{close_quotes} or sputter slice zone plates. Wenbing Yun, Argonne National Laboratory (ANL), described characterization of jelly roll and lithographically produced zone plates and described the application of zone plates to focus extremely narrow bandwidths by nuclear resonance. This report summarizes the presentations of the workshop subgroup on hard x-ray microprobes.

  20. Monochromatic Mammographic Imaging Using X-Ray Polycapillary Optics

    National Research Council Canada - National Science Library

    Sugiro, Francisca

    2002-01-01

    .... However, conventionaI laboratory sources normally have insufficient intensity. Polycapillary x-ray optics can be used to efficiently produce an intense parallel beam, which can be diffracted from a crystal to create monochromatic radiation...

  1. Use of X-Ray Fluorescence Spectrometry to Determine Trace ...

    African Journals Online (AJOL)

    This paper deals with application of X-ray fluorescence spectrometry for the detection of trace elements in graphic. An X-ray spectrometer was constructed and used to carry out measurements on graphite spheres impregnated with different chemical elements. The intensities of the lines of these trace elements, as function of ...

  2. Thermal deformation of cryogenically cooled silicon crystals under intense X-ray beams: measurement and finite-element predictions of the surface shape

    Science.gov (United States)

    Zhang, Lin; Sánchez del Río, Manuel; Monaco, Giulio; Detlefs, Carsten; Roth, Thomas; Chumakov, Aleksandr I.; Glatzel, Pieter

    2013-01-01

    X-ray crystal monochromators exposed to white-beam X-rays in third-generation synchrotron light sources are subject to thermal deformations that must be minimized using an adequate cooling system. A new approach was used to measure the crystal shape profile and slope of several cryogenically cooled (liquid nitrogen) silicon monochromators as a function of beam power in situ and under heat load. The method utilizes multiple angular scans across the Bragg peak (rocking curve) at various vertical positions of a narrow-gap slit downstream from the monochromator. When increasing the beam power, the surface of the liquid-nitrogen-cooled silicon crystal deforms from a concave shape at low heat load to a convex shape at high heat load, passing through an approximately flat shape at intermediate heat load. Finite-element analysis is used to calculate the crystal thermal deformations. The simulated crystal profiles and slopes are in excellent agreement with experiments. The parameters used in simulations, such as material properties, absorbed power distribution on the crystal and cooling boundary conditions, are described in detail as they are fundamental for obtaining accurate results. PMID:23765298

  3. 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 ...

  4. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... diagnosis and treatment. No radiation remains in a patient's body after an x-ray examination. X-rays usually have no side effects in the typical diagnostic range for this exam. Risks There is always a slight chance of cancer from excessive exposure to radiation. However, the benefit ...

  5. Bone X-Ray (Radiography)

    Medline Plus

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

  6. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... widely available in emergency rooms, physician offices, ambulatory care centers, nursing homes and other locations, making it convenient for both patients and physicians. Because x-ray imaging is fast and easy, it is ... Radiation Exposure Special care is taken during x-ray examinations to use ...

  7. Chandra's X-ray Vision

    Indian Academy of Sciences (India)

    1999-07-23

    Jul 23, 1999 ... GENERAL I ARTICLE. Chandra's X-ray Vision. K P Singh. Chandra X-ray Observatory (CXO) is a scientific satellite (moon/ chandra), named after the Indian-born Nobel laureate. Subrahmanyan Chandrasekhar - one of the foremost astro- physicists of the twentieth century and popularly known as. Chandra.

  8. X-Ray Exam: Ankle

    Science.gov (United States)

    ... radiation through the ankle, and black and white images of the bones and soft tissues are recorded on a computer or special X-ray film. Dense structures that block the passage of the X-ray beam through the body, such as bones, appear white. Softer body tissues, ...

  9. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... Info Images/Videos About Us News Physician Resources Professions Site Index A-Z X-ray (Radiography) - Bone ... current x-ray images for diagnosis and disease management. top of page How is the procedure performed? ...

  10. 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.

  11. Kβ/Kα X-ray intensity ratios for some elements in the atomic number range 28≤Z≤39 at 16.896 keV

    Directory of Open Access Journals (Sweden)

    R. Yılmaz

    2017-07-01

    Full Text Available The K shell intensity ratios (Kβ/Kα have been experimentally determined for some elements in the atomic number range 28 ≤ Z ≤ 39 by using secondary excitation method. K X-rays emitted by samples have been counted by a Si (Li detector with 160 eV resolutions at 5.9 keV. The measured values were compared with the theoretical and experimental values. In general, the values obtained are in good agreement with the calculated values.

  12. The effect of image receptor change on radiation exposure to patients in the intensive care of chest X-ray examinations

    Energy Technology Data Exchange (ETDEWEB)

    Kettunen, A. [Oulu Polytechnic, Oulu (Finland); Servomaa, A. [STUK - Radiation and Nuclear Safety Authority, Helsinki (Finland)

    2003-06-01

    Digital imaging is becoming increasingly popular in radiology. The use of imaging plates is now common even in small X-ray departments and health centers. The effect of the imaging plates on dose and image quality has been studied and compared with the conventional film-screen system. In the beginning, the change in image receptor may cause many problems with regard to the radiation dose to patients. With a film-screen system, the optical density of the film effectively limits the dose to the patient, but in digital imaging this limitation does not exist. When a film-screen system is changed to a digital imaging plate system, there is no evidence indicating whether the dose is increasing or decreasing. In this study, the dose to the patient in bedside chest examinations was studied over a five-year period. (orig.)

  13. 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...

  14. X-Ray Optics Research

    Science.gov (United States)

    1990-09-20

    OF FUNDING NUMBERS Building 410 PORM POET TS OKUI Bolig FBDC2032648ELEMENT NO. NO. NO ACCESiON NO 11. TITLE (include Security Classification) X - Ray Optics Research...by block number) This report describes work conducted during the period I October 1987 through 30 April 1990, under Contract AFOSR-88-00l0, " X - Ray Optics Research...growth and structure of multilayer interfaces. This capability is central to the development of future materials for multilayer x - ray optics , because

  15. 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 ... code: Phone no: Thank you! Do you have a personal story about radiology? Share your patient story ...

  16. 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...

  17. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... of any bone in the body, including the hand, wrist, arm, elbow, shoulder, spine, pelvis, hip, thigh, ... to current x-ray images for diagnosis and disease management. top of page How is the procedure ...

  18. Bone X-Ray (Radiography)

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    Full Text Available Toggle navigation ... x-ray uses a very small dose of ionizing radiation to produce pictures of any bone in the body. It is commonly used to diagnose fractured bones or joint dislocation. Bone ...

  19. Bone X-Ray (Radiography)

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    Full Text Available ... x-ray machine is a compact apparatus that can be taken to the patient in a hospital ... so that any change in a known abnormality can be monitored over time. Follow-up examinations are ...

  20. Bone X-Ray (Radiography)

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    Full Text Available ... to produce pictures of any bone in the body. It is commonly used to diagnose fractured bones ... x-rays involves exposing a part of the body to a small dose of ionizing radiation to ...

  1. Bone X-Ray (Radiography)

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

  2. Bone X-Ray (Radiography)

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

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

  4. Bone X-Ray (Radiography)

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    Full Text Available ... position possible that still ensures x-ray image quality. top of page Who interprets the results and ... emergency rooms, physician offices, ambulatory care centers, nursing homes and other locations, making it convenient for both ...

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    Full Text Available ... patient. top of page How does the procedure work? X-rays are a form of radiation like ... taken of the unaffected limb, or of a child's growth plate (where new bone is forming), for ...

  6. Bone X-Ray (Radiography)

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

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    Full Text Available ... will analyze the images and send a signed report to your primary care or referring physician , who ... Medicine Radiation Safety How to Read Your Radiology Report Images related to X-ray (Radiography) - Bone Sponsored ...

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    Full Text Available ... fracture. guide orthopedic surgery, such as spine repair/fusion, joint replacement and fracture reductions. look for injury, ... CT Exams Arthritis X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety How to Read Your Radiology ...

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    Full Text Available ... here Images × Image Gallery Radiological technologist preparing to take an arm x-ray on a patient. View ... and/or your insurance provider to get a better understanding of the possible charges you will incur. ...

  10. Bone X-Ray (Radiography)

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    Full Text Available ... in evaluating the hips of children with congenital problems. top of page This page was reviewed on ... Exams Arthritis X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety How to Read Your Radiology Report ...

  11. Bone X-Ray (Radiography)

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    Full Text Available ... white on the x-ray, soft tissue shows up in shades of gray and air appears black. ... who will discuss the results with you. Follow-up examinations may be necessary. Your doctor will explain ...

  12. Bone X-Ray (Radiography)

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

  13. Bone X-Ray (Radiography)

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

  14. Bone X-Ray (Radiography)

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    Full Text Available ... tissue shows up in shades of gray and air appears black. Until recently, x-ray images were ... imaged. When necessary, sandbags, pillows or other positioning devices will be used to help you maintain the ...

  15. Bone X-Ray (Radiography)

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    Full Text Available ... current x-ray images for diagnosis and disease management. top of page How is the procedure performed? ... procedure varies. See the Safety page for more information about radiation dose. Women should always inform their ...

  16. Bone X-Ray (Radiography)

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    Full Text Available ... patient. top of page How does the procedure work? X-rays are a form of radiation like ... little information about muscles, tendons or joints. An MRI may be more useful in identifying bone and ...

  17. Bone X-Ray (Radiography)

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    Full Text Available ... The teddy bear denotes child-specific content. Related Articles and Media Arthritis X-ray, Interventional Radiology and ... community, you can search the ACR-accredited facilities database . This website does not provide cost information. The ...

  18. Bone X-Ray (Radiography)

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    Full Text Available ... very small dose of ionizing radiation to produce pictures of any bone in the body. It is ... a small dose of ionizing radiation to produce pictures of the inside of the body. X-rays ...

  19. Bone X-Ray (Radiography)

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    Full Text Available ... pelvis, hip, thigh, knee, leg (shin), ankle or foot. top of page What are some common uses ... to current x-ray images for diagnosis and disease management. top of page How is the procedure ...

  20. Bone X-Ray (Radiography)

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    Full Text Available ... commonly used to diagnose fractured bones or joint dislocation. Bone x-rays are the fastest and easiest ... is used to: diagnose fractured bones or joint dislocation. demonstrate proper alignment and stabilization of bony fragments ...

  1. Bone X-Ray (Radiography)

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

  2. Bone X-Ray (Radiography)

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    Full Text Available ... in metabolic conditions. assist in the detection and diagnosis of bone cancer . locate foreign objects in soft ... frequently compared to current x-ray images for diagnosis and disease management. top of page How is ...

  3. Bone X-Ray (Radiography)

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    Full Text Available ... patient. top of page How does the procedure work? X-rays are a form of radiation like ... radiation dose for this procedure varies. See the Safety page for more information about radiation dose. Women ...

  4. Bone X-Ray (Radiography)

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    Full Text Available ... a form of radiation like light or radio waves. X-rays pass through most objects, including the ... individual patient's condition. Ultrasound imaging, which uses sound waves instead of ionizing radiation to create diagnostic images, ...

  5. Bone X-Ray (Radiography)

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    Full Text Available ... for more information about pregnancy and x-rays. A Word About Minimizing Radiation Exposure Special care is ... taking our brief survey: Survey Do you have a personal story about radiology? Share your patient story ...

  6. Bone X-Ray (Radiography)

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

  7. Bone X-Ray (Radiography)

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    Full Text Available ... evaluation with additional views or a special imaging technique. A follow-up examination may also be necessary ... radiology protection organizations continually review and update the technique standards used by radiology professionals. Modern x-ray ...

  8. Bone X-Ray (Radiography)

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

  9. Bone X-Ray (Radiography)

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    Full Text Available ... current x-ray images for diagnosis and disease management. top of page How is the procedure performed? ... information you were looking for? Yes No Please type your comment or suggestion into the following text ...

  10. Bone X-Ray (Radiography)

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    Full Text Available ... small burst of radiation that passes through the body, recording an image on photographic film or a special detector. Different parts of the body absorb the x-rays in varying degrees. Dense ...

  11. Bone X-Ray (Radiography)

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    Full Text Available ... bone in the body, including the hand, wrist, arm, elbow, shoulder, spine, pelvis, hip, thigh, knee, leg ( ... x-ray tube is connected to a flexible arm that is extended over the patient while an ...

  12. Bone X-Ray (Radiography)

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

  13. Bone X-Ray (Radiography)

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    Full Text Available ... pass through them. As a result, bones appear white on the x-ray, soft tissue shows up ... for a physician to view and assess bone injuries, including fractures, and joint abnormalities, such as arthritis. ...

  14. Bone X-Ray (Radiography)

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    Full Text Available ... abnormal bone growths and bony changes seen in metabolic conditions. assist in the detection and diagnosis of ... have very controlled x-ray beams and dose control methods to minimize stray (scatter) radiation. This ensures ...

  15. Bone X-Ray (Radiography)

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    Full Text Available ... may also be asked to remove jewelry, removable dental appliances, eye glasses and any metal objects or clothing that might interfere with the x-ray images. Women should always inform their physician and ...

  16. Interfraction rotation of the prostate as evaluated by kilovoltage X-ray fiducial marker imaging in intensity-modulated radiotherapy of localized prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Graf, Reinhold; Boehmer, Dirk; Budach, Volker [Charite Universitaetsmedizin Berlin, Department of Radiation Oncology, Campus Virchow-Klinikum, Berlin (Germany); Wust, Peter, E-mail: peter.wust@charite.de [Charite Universitaetsmedizin Berlin, Department of Radiation Oncology, Campus Virchow-Klinikum, Berlin (Germany)

    2012-01-01

    To quantify the daily rotation of the prostate during a radiotherapy course using stereoscopic kilovoltage (kV) x-ray imaging and intraprostatic fiducials for localization and positioning correction. From 2005 to 2009, radio-opaque fiducial markers were inserted into 38 patients via perineum into the prostate. The ExacTrac/Novalis Body X-ray 6-day image acquisition system (ET/NB; BrainLab AG, Feldkirchen, Germany) was used to determine and correct the target position. During the first period in 10 patients we recorded all rotation errors but used only Y (table) for correction. For the next 28 patients we used for correction all rotational coordinates, i.e., in addition Z (superior-inferior [SI] or roll) and X (left-right [LR] or tilt/pitch) according to the fiducial marker position by use of the Robotic Tilt Module and Varian Exact Couch. Rotation correction was applied above a threshold of 1 Degree-Sign displacement. The systematic and random errors were specified. Overall, 993 software-assisted rotational corrections were performed. The interfraction rotation errors of the prostate as assessed from the radiodense surrogate markers around the three axes Y, Z, and X were on average 0.09, -0.52, and -0.01 Degree-Sign with standard deviations of 2.01, 2.30, and 3.95 Degree-Sign , respectively. The systematic uncertainty per patient for prostate rotation was estimated with 2.30, 1.56, and 4.13 Degree-Sign and the mean random components with 1.81, 2.02, and 3.09 Degree-Sign . The largest rotational errors occurred around the X-axis (pitch), but without preferring a certain orientation. Although the error around Z (roll) can be compensated on average by a transformation with 4 coordinates, a significant error around X remains and advocates the full correction with 6 coordinates. Rotational errors as assessed via daily stereoscopic online imaging are significant and dominate around X. Rotation possibly degrades the dosimetric coverage of the target volume and may require

  17. Application of X-ray Optics to Energy-Dispersive Spectroscopy.

    Science.gov (United States)

    McCarthy; McMillan

    1998-11-01

    : X-ray optics have been used in X-ray analytical instruments for several years. Applications of X-ray optics have been reported in X-ray diffraction, X-ray fluorescence, and wavelength dispersive spectroscopy. X-ray optics have been used to increase the X-ray flux incident on the sample or to direct and focus emitted X-rays from a sample. We report here the use of a grazing incidence optic (GIO) as a flux-enhancing collimator for use with an energy-dispersive (ED) detector used to perform electron beam microanalysis. We found that the GIO in combination with an ED spectrometer (EDS) provides substantial intensity gain for X-ray lines with energy below 1 keV. The GIO is also found to provide a modest focus effect, and introduces minimal spectral artifacts.

  18. 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)

  19. 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.

  20. Harmonic lasing in X-ray FELs

    Energy Technology Data Exchange (ETDEWEB)

    Schneidmiller, E.A.; Yurkov, M.V.

    2012-05-15

    Harmonic lasing in a free electron laser with a planar undulator (under the condition that the fundamental frequency is suppressed) might be a cheap and efficient way of extension of wavelength ranges of existing and planned X-ray FEL facilities. Contrary to nonlinear harmonic generation, harmonic lasing can provide much more intense, stable, and narrow-band FEL beam which is easier to handle due to the suppressed fundamental frequency. In this paper we perform a parametrization of the solution of the eigenvalue equation for lasing at odd harmonics, and present an explicit expression for FEL gain length, taking into account all essential effects. We propose and discuss methods for suppression of the fundamental harmonic. We also suggest a combined use of harmonic lasing and lasing at the retuned fundamental wavelength in order to reduce bandwidth and to increase brilliance of X-ray beam at saturation. Considering 3rd harmonic lasing as a practical example, we come to the conclusion that it is much more robust than usually thought, and can be widely used in the existing or planned X-ray FEL facilities. In particular, LCLS after a minor modification can lase to saturation at the 3rd harmonic up to the photon energy of 25-30 keV providing multi-gigawatt power level and narrow bandwidth. As for the European XFEL, harmonic lasing would allow to extend operating range (ultimately up to 100 keV), to reduce FEL bandwidth and to increase brilliance, to enable two-color operation for pump-probe experiments, and to provide more flexible operation at different electron energies. Similar improvements can be realized in other X-ray FEL facilities with gap-tunable undulators like FLASH II, SACLA, LCLS II, etc. Harmonic lasing can be an attractive option for compact X-ray FELs (driven by electron beams with a relatively low energy), allowing the use of the standard undulator technology instead of small-gap in-vacuum devices. Finally, in this paper we discover that in a part of the

  1. Why Do I Need X-Rays?

    Science.gov (United States)

    ... Child at Risk for Early Childhood Tooth Decay? Pacifiers Have Negative and Positive Effects The History of ... Sets the Record Straight on Dental X-Rays Types of X-Rays X-Rays Help Predict Permanent ...

  2. Nanometer x-ray lithography

    Science.gov (United States)

    Hartley, Frank T.; Khan Malek, Chantal G.

    1999-10-01

    New developments for x-ray nanomachining include pattern transfer onto non-planar surfaces coated with electrodeposited resists using synchrotron radiation x-rays through extremely high-resolution mask made by chemically assisted focused ion beam lithography. Standard UV photolithographic processes cannot maintain sub-micron definitions over large variation in feature topography. The ability of x-ray printing to pattern thin or thick layers of photoresist with high resolution on non-planar surfaces of large and complex topographies with limited diffraction and scattering effects and no substrate reflection is known and can be exploited for patterning microsystems with non-planar 3D geometries as well as multisided and multilayered substrates. Thin conformal coatings of electro-deposited positive and negative tone photoresist have been shown to be x-ray sensitive and accommodate sub-micro pattern transfer over surface of extreme topographical variations. Chemically assisted focused ion beam selective anisotropic erosion was used to fabricate x-ray masks directly. Masks with feature sizes less than 20 nm through 7 microns of gold were made on bulk silicon substrates and x-ray mask membranes. The technique is also applicable to other high density materials. Such masks enable the primary and secondary patterning and/or 3D machining of Nano-Electro-Mechanical Systems over large depths or complex relief and the patterning of large surface areas with sub-optically dimensioned features.

  3. A hard X-ray nanoprobe beamline for nanoscale microscopy.

    Science.gov (United States)

    Winarski, Robert P; Holt, Martin V; Rose, Volker; Fuesz, Peter; Carbaugh, Dean; Benson, Christa; Shu, Deming; Kline, David; Stephenson, G Brian; McNulty, Ian; Maser, Jörg

    2012-11-01

    The Hard X-ray Nanoprobe Beamline (or Nanoprobe Beamline) is an X-ray microscopy facility incorporating diffraction, fluorescence and full-field imaging capabilities designed and operated by the Center for Nanoscale Materials and the Advanced Photon Source at Sector 26 of the Advanced Photon Source at Argonne National Laboratory. This facility was constructed to probe the nanoscale structure of biological, environmental and material sciences samples. The beamline provides intense focused X-rays to the Hard X-ray Nanoprobe (or Nanoprobe) which incorporates Fresnel zone plate optics and a precision laser sensing and control system. The beamline operates over X-ray energies from 3 to 30 keV, enabling studies of most elements in the periodic table, with a particular emphasis on imaging transition metals.

  4. Use of high-intensity sonication for pre-treatment of biological tissues prior to multielemental analysis by total reflection X-ray fluorescence spectrometry

    Science.gov (United States)

    La Calle, Inmaculada De; Costas, Marta; Cabaleiro, Noelia; Lavilla, Isela; Bendicho, Carlos

    2012-01-01

    In this work, two ultrasound-based procedures are developed for sample preparation prior to determination of P, K, Ca, Cr, Mn, Fe, Ni, Cu, Zn, As, Se and Sr in biological tissues by total reflection X-ray fluorescence spectrometry. Ultrasound-assisted extraction by means of a cup-horn sonoreactor and ultrasonic-probe slurry sampling were compared with a well-established procedure such as magnetic agitation slurry sampling. For that purpose, seven certified reference materials and different real samples of animal tissue were used. Similar accuracy and precision is obtained with the three sample preparation approaches tried. Limits of detection were dependent on both the sample matrix and the sample pre-treatment used, best values being achieved with ultrasound-assisted extraction. Advantages of ultrasound-assisted extraction include reduced sample handling, decreased contamination risks (neither addition of surfactants nor use of foreign objects inside the extraction vial), simpler background (no solid particles onto the sample carrier) and improved recovery for some elements such as P. A mixture of 10% v/v HNO3 + 20-40% v/v HCl was suitable for extraction from biological tissues.

  5. Center for X-Ray Optics, 1992

    Energy Technology Data Exchange (ETDEWEB)

    1993-08-01

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

  6. X-ray detector physics and applications; Proceedings of the Meeting, San Diego, CA, July 23, 24, 1992

    Science.gov (United States)

    Hoover, Richard B. (Editor)

    1993-01-01

    Recent developments in X-ray and hard X-ray imaging detector, high-intensity sources, hard X-ray imaging optics, calibration, and detection technologies are discussed. Particular attention is given to a high-MTF X-ray image intensifier, application of monolithic CdZnTe linear solid state ionization detectors for X-ray imaging, magnetic response of high-Tc superconductors to X-ray radiation and detection of X-rays, laboratory soft X-ray source with foil target, detection of explosive materials using nuclear radiation, energy response of astronomical CCD X-ray detectors, calibration techniques for high-flux X-ray detectors, fabrication of grazing-incidence optics using flow-polishing techniques, and numerical simulations for capillary-based X-ray optics. (No individual items are abstracted in this volume)

  7. Quantum effets in nonresonant X-ray scattering

    Energy Technology Data Exchange (ETDEWEB)

    Slowik, Jan Malte

    2015-11-15

    experiments. In the quantum theory it has however been revealed that X-ray scattering patterns of electronic motion are related to complex spatio-temporal correlations, instead of the instantaneous electron density. I scrutinize the time-resolved scattering pattern from coherent electronic wave packets. I show that timeresolved PCI recovers the instantaneous electron density of electronic motion. For the far-field diffraction scattering pattern, I analyze the influence of photon energy resolution of the detector. Moreover, I demonstrate that X-ray scattering from a crystal of identical wave packets also recovers the instantaneous electron density. I point out that a generalized electron density propagator of the wave packet can be reconstructed from a scattering experiment. Finally, I propose timeresolved Compton scattering of electronic wave packets. I show that X-ray scattering with large energy transfer can be used to recover the instantaneous momentum space density of the target. The third topic of this dissertation is Compton scattering in single molecule coherent diffractive imaging (CDI). The structure determination of single macromolecules via CDI is one of the key applications of XFELs. The structure of the molecule can be reconstructed from the elastic diffraction pattern. Inelastic X-ray scattering generates a background signal, which I determine for typical high-intensity imaging conditions. I find that at high X-ray fluence the background signal becomes dominating, posing a problem for high resolution imaging. The strong ionization by the X-ray pulse may ionize several electrons per atom. Scattering from these free electrons makes a major contribution to the background signal. I present and discuss detailed numerical studies for different X-ray fluence and photon energy.

  8. Strain in nanoscale Germanium hut clusters on Si(001) studied by x-ray diffraction

    DEFF Research Database (Denmark)

    Steinfort, A.J.; Scholte, P.M.L.O.; Ettema, A.

    1996-01-01

    Scanning tunneling microscopy and synchrotron x-ray diffraction have been used to investigate nanoscale Ge hut clusters on Si(001). We have been able to identify the contributions to the scattered x-ray intensity which arise solely from the hut clusters and have shown that x-ray diffraction can b...

  9. Time Resolved X-Ray Scattering of molecules in Solution

    DEFF Research Database (Denmark)

    Brandt van Driel, Tim

    of bringing the data from measurement to analysis. Bridging the experimental design and challenges of the experiments from X-ray synchrotrons to the newly available X-ray Free Electron Laser sources (XFEL).LCLS in California is the first XFEL to come online and delivers intense 30fs X-ray pulses, orders...... in the purpose built CSPAD detector is presented and applied to the data to highlight the relevance of this work. Thereby showing the ability to capture a molecular movie on the sub-ps time-scale....

  10. High Brightness Electron Gun for X-Ray Source

    CERN Document Server

    Ohsawa, Satoshi; Ikeda, Mitsuo; Kanno, K; Sugimura, Takashi; Tawada, Masafumi

    2005-01-01

    A new electron-gun system is under development in order to increase X-ray from a rotating target. In commercial X-ray sources electron beams usually hit targets at the outer part. Owing to deformation by centrifugal force, there has been a limit on electron beam intensities. In order to overcome this difficulty, we adopted a new injection system which strikes inside of a ring-shape projection on a rotating target. It has an advantage in that heated-up points have supports back side against centrifugal force. This merit allows us to raise electron beam to give stronger X-rays.

  11. Simulation of high currents in x-ray flash tubes

    Science.gov (United States)

    Germer, R.; Sato, E.

    2008-11-01

    The discharge in linear plasma X-ray flash tubes ( Sato tubes ) is simulated. For the geometry of a cylinder cathode outside and an anode in the centre, the electrical fields and potentials are calculated and the propagation of electrons are studied. Space charge limits the current in the initial phase strongly. Replacing the vacuum by plasma from the anode evaporation, it is possible to get increasing current and strong X-ray pulses. Space charge is important for the high intensity X-ray production up to the end of the emission.

  12. Jovian bremsstrahlung X-rays - A Ulysses prediction

    Science.gov (United States)

    Waite, J. H., Jr.; Boice, D. C.; Hurley, K. C.; Stern, S. A.; Sommer, M.

    1992-01-01

    Modeling results reported here show that precipitating auroral electrons with sufficient energy to be consistent with the Voyager UVS observations produce bremsstrahlung X-rays with sufficient energy and intensity to be detected by the Solar Flare X-ray and Cosmic-Ray-Burst Instrument on board the Ulysses spacecraft. The detection of such bremsstrahlung X-rays at Jupiter would provide strong evidence for the electron-precipitation mechanism, although it does not rule out the possibility of some heavy ion involvement, and thus makes a significant contribution toward solving the mystery of the Jovian aurora.

  13. Soft x-ray excitonics

    Science.gov (United States)

    Moulet, A.; Bertrand, J. B.; Klostermann, T.; Guggenmos, A.; Karpowicz, N.; Goulielmakis, E.

    2017-09-01

    The dynamic response of excitons in solids is central to modern condensed-phase physics, material sciences, and photonic technologies. However, study and control have hitherto been limited to photon energies lower than the fundamental band gap. Here we report application of attosecond soft x-ray and attosecond optical pulses to study the dynamics of core-excitons at the L2,3 edge of Si in silicon dioxide (SiO2). This attosecond x-ray absorption near-edge spectroscopy (AXANES) technique enables direct probing of the excitons’ quasiparticle character, tracking of their subfemtosecond relaxation, the measurement of excitonic polarizability, and observation of dark core-excitonic states. Direct measurement and control of core-excitons in solids lay the foundation of x-ray excitonics.

  14. X-ray tensor tomography

    Science.gov (United States)

    Malecki, A.; Potdevin, G.; Biernath, T.; Eggl, E.; Willer, K.; Lasser, T.; Maisenbacher, J.; Gibmeier, J.; Wanner, A.; Pfeiffer, F.

    2014-02-01

    Here we introduce a new concept for x-ray computed tomography that yields information about the local micro-morphology and its orientation in each voxel of the reconstructed 3D tomogram. Contrary to conventional x-ray CT, which only reconstructs a single scalar value for each point in the 3D image, our approach provides a full scattering tensor with multiple independent structural parameters in each volume element. In the application example shown in this study, we highlight that our method can visualize sub-pixel fiber orientations in a carbon composite sample, hence demonstrating its value for non-destructive testing applications. Moreover, as the method is based on the use of a conventional x-ray tube, we believe that it will also have a great impact in the wider range of material science investigations and in future medical diagnostics. The authors declare no competing financial interests.

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

    Directory of Open Access Journals (Sweden)

    Cannavò Antonino

    2018-01-01

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

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

    Science.gov (United States)

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

    2018-01-01

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

  17. Clinical and radiological evaluation of ARDS. Comparison of conventional X-ray procedures and computed tomography in patients from the intensive care unit. Klinische und radiologische Beurteilung des ARDS. Vergleich von konventionellen Roentgenbildern und Computertomogramm bei Intensivpatienten

    Energy Technology Data Exchange (ETDEWEB)

    Hirt, S.W.

    1985-08-19

    Thirty patients under long-term artificial respiration being at risk of or suffering from ARDS were observed on the intensive care unit right from the beginning of treatment. In all cases, the lungs were visualised by means of computed tomography. Computed tomography of the lungs provided valuable information as to the pulmonal distribution of ARDS-related changes. In gradually developing acute respiratory insufficiency caused by parenchymal changes that start from the paravertebral regions CT scans also permitted the so-called 'silent period' to be ascertained that is always seen to escape radiological detection. Comparative evaluations confirmed the diagnostic superiority of computed tomography to conventional X-ray procedures and arterial blood gas analysis in those ARDS patients where the tissue changes begin in the dorsal sections of the lungs. (orig./MBC).

  18. Development of cable fed flash X-ray (FXR) system

    Science.gov (United States)

    Menon, Rakhee; Mitra, S.; Patel, A. S.; Kumar, R.; Singh, G.; Senthil, K.; Kumar, Ranjeet; Kolge, T. S.; Roy, Amitava; Acharya, S.; Biswas, D.; Sharma, Archana

    2017-08-01

    Flash X-ray sources driven by pulsed power find applications in industrial radiography, and a portable X-ray source is ideal where the radiography needs to be taken at the test site. A compact and portable flash X-ray (FXR) system based on a Marx generator has been developed with the high voltage fed to the FXR tube via a cable feed-through arrangement. Hard bremsstrahlung X-rays of few tens of nanosecond duration are generated by impinging intense electron beams on an anode target of high Z material. An industrial X-ray source is developed with source size as low as 1 mm. The system can be operated from 150 kV to 450 kV peak voltages and a dose of 10 mR has been measured at 1 m distance from the source window. The modeling of the FXR source has been carried out using particle-in-cell and Monte Carlo simulations for the electron beam dynamics and X-ray generation, respectively. The angular dose profile of X-ray has been measured and compared with the simulation.

  19. Coherent methods in X-ray scattering

    Energy Technology Data Exchange (ETDEWEB)

    Gorobtsov, Oleg

    2017-05-15

    X-ray radiation has been used to study structural properties of materials for more than a hundred years. Construction of extremely coherent and bright X-ray radiation sources such as free electron lasers (FELs) and latest generationstorage rings led to rapid development of experimental methods relying on high radiation coherence. These methods allow to perform revolutionary studies in a wide range of fields from solid state physics to biology. In this thesis I focus on several important problems connected with the coherent methods. The first part considers applications of dynamical diffraction theory on crystals to studies with coherent X-ray radiation. It presents the design of a high-resolution spectrometer for free electron lasers that should allow to resolve spectral structure of individual FEL pulses. The spectrometer is based on the principle of dynamical diffraction focusing. The knowledge of individual FEL pulse spectra is necessary for understanding FEL longitudinal coherence. In the same part I present quasi-kinematical approximation to dynamical theory which allows to treat analytically phase effects observed in X-ray coherent imaging on nanocrystals. These effects may play a big role when methods such as ptychography are used to study crystalline samples. The second part deals with measurements of FEL coherence properties using intensity - intensity interferometry. Results of several experiments performed at FELs FLASH and LCLS are revealed in this section. I have developed models and theories to explain the behavior observed in experiments on FLASH. These models allowed to extract information about external positional jitter of FEL pulses and secondary beams present in FEL radiation. In the LCLS experiment the Hanbury Brown and Twiss type interferometry was performed on Bragg peaks from colloidal crystal. This did not require additional measurements without the sample and information was extracted directly from diffraction patterns. Therefore intensity-intensity

  20. 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. ...

  1. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... dislocations. In elderly or patients with osteoporosis, a hip fracture may be clearly seen on a CT scan, while it may be barely seen, if at all, on a hip x-ray. For suspected spine injury or other ...

  2. Bone X-Ray (Radiography)

    Medline Plus

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

  3. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... small burst of radiation that passes through the body, recording an image on photographic film or a special detector. Different ... This ensures that those parts of a patient's body not being imaged receive minimal radiation ... x-ray images are among the clearest, most detailed views of ...

  4. 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 ... may be placed over your pelvic area or breasts when feasible to protect from ... chance of cancer from excessive exposure to radiation. However, the benefit ...

  5. 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.

  6. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... is commonly used to diagnose fractured bones or joint dislocation. Bone x-rays are the fastest and easiest way for your doctor ... shin), ankle or foot. top of page What are some common uses of the ... bones or joint dislocation. demonstrate proper alignment and stabilization of bony ...

  7. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... small burst of radiation that passes through the body, recording an image on photographic film or a special detector. Different ... bear denotes child-specific content. Related Articles and Media ... Images related to X-ray (Radiography) - Bone Sponsored by ...

  8. 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 Resources Professions Site Index A-Z X-ray (Radiography) - Bone ...

  9. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... evaluated). MRI can also detect subtle or occult fractures or bone bruises (also called bone contusions or microfractures) not visible on x-ray images. CT is being used widely to assess trauma patients in ... fractures, subtle fractures or dislocations. In elderly or patients ...

  10. X-Ray Exam: Pelvis

    Science.gov (United States)

    ... pelvis and an image is recorded on special film or a computer. This image shows the bones of the pelvis, which include the two hip bones, plus the sacrum and the coccyx (tailbone). The X-ray image is black and white. Dense body parts that block the passage of the X- ...

  11. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... any possibility that they are pregnant. Many imaging tests are not performed during pregnancy so as not to expose the fetus to ... See the Safety page for more information about pregnancy and x-rays. A Word About Minimizing ... imaging tests and treatments have special pediatric considerations. The teddy ...

  12. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... way for your doctor to view and assess bone fractures, injuries and joint abnormalities. This exam requires little ... way for a physician to view and assess bone injuries, including fractures, and joint abnormalities, such as arthritis. X-ray ...

  13. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... for a physician to view and assess bone injuries, including fractures, and joint abnormalities, such as arthritis. X-ray equipment is relatively inexpensive and widely available in emergency rooms, physician offices, ambulatory care centers, nursing homes and other locations, making it ...

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

    NARCIS (Netherlands)

    Groot, F.M.F. de

    2000-01-01

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

  15. Generation of intense high harmonics: (i) To test and improve resolution of accumulative X-ray streak camera; (ii) To study the effects of Carrier envelope phase on XUV super continuum generation by polarization gating

    Science.gov (United States)

    Shakya, Mahendra Man

    The first part of this thesis describes our novel design, test, and application of our X-ray streak camera to the pulse duration measurement of soft X-rays. We demonstrated a significant improvement in the resolution of the x-ray streak camera by reducing the electron beam size in the deflection plates. This was accomplished by adding a slit in front of the focusing lens and the deflection plates. The temporal resolution reached 280 fs when the slit width was 5 mum. The camera was operated in an accumulative mode and tested by using a 25 fs laser with 2 kHz repetition rate and 1-2% RMS pulse energy stability. We conclude that deflection aberrations, which limit the resolution of the camera, can be appreciably reduced by eliminating the wide-angle electrons. We also employed the same streak camera to demonstrate that it is capable of measuring the pulse duration of X-rays. We measured the pulse duration of X-rays emitted from Ni-like Ag and Cd grazing-incidence laser to be ˜5ps. The measured value agrees with the prediction made by the model and the measurement made by changing the delay as a function of the pulse duration. The streak camera was also tested with various sources of X-ray such as high harmonics generation of soft x-rays from an argon atom using a high power Ti:sapphire laser source of KLS. The result of the measurement manifests its capability for serving as a detector in the study of ultrafast dynamics in the field of physics, chemistry, biology and medical sciences. The second part of this thesis describes our design of a spectrometer to study the effect of the Carrier envelope (CE) phase on polarization gated extreme-ultraviolet (XUV) super-continuum generation. Because the challenge of making single shot experiment possible is to generate a sufficient number of photons, our setup has been built to allow generation of high order harmonics at the maximum phase matched pressure. This is the first time to our knowledge that phase matching in the

  16. Hard X-ray laue monochromator

    OpenAIRE

    Kocharian, Vagan Rashidovich; Gogolev, Aleksey Sergeevich; Kiziridi, A. A.; Batranin, Andrey Viktorovich; Muradyan, T. R.

    2016-01-01

    Experimental studies of X-ray diffraction from reflecting atomic planes (1011) of X-cut quartz single crystal in Laue geometry influenced by the temperature gradient were carried out. It is shown that by using the temperature gradient it is possible to reflect a hard Xray beam with photon energy near the 100 keV with high efficiency. It has been experimentally proved that the intensity of the reflected beam can be increased by more than order depending on the value of the temperature gradient.

  17. Heterodyne x-ray diffuse scattering from coherent phonons.

    Science.gov (United States)

    Kozina, M; Trigo, M; Chollet, M; Clark, J N; Glownia, J M; Gossard, A C; Henighan, T; Jiang, M P; Lu, H; Majumdar, A; Zhu, D; Reis, D A

    2017-09-01

    Here, we report Fourier-transform inelastic x-ray scattering measurements of photoexcited GaAs with embedded ErAs nanoparticles. We observe temporal oscillations in the x-ray scattering intensity, which we attribute to inelastic scattering from coherent acoustic phonons. Unlike in thermal equilibrium, where inelastic x-ray scattering is proportional to the phonon occupation, we show that the scattering is proportional to the phonon amplitude for coherent states. The wavevectors of the observed phonons extend beyond the excitation wavevector. The nanoparticles break the discrete translational symmetry of the lattice, enabling the generation of large wavevector coherent phonons. Elastic scattering of x-ray photons from the nanoparticles provides a reference for heterodyne mixing, yielding signals proportional to the phonon amplitude.

  18. XIPE the X-Ray Imaging Polarimetry Explorer

    Science.gov (United States)

    Soffitta, Paolo; Barcons, Xavier; Bellazzini, Ronaldo; Braga, Joao; Costa, Enrico; Fraser, George W.; Gburek, Szymon; Huovelin, Juhani; Matt, Giorgio; Pearce, Mark; hide

    2013-01-01

    X-ray polarimetry, sometimes alone, and sometimes coupled to spectral and temporal variability measurements and to imaging, allows a wealth of physical phenomena in astrophysics to be studied. X-ray polarimetry investigates the acceleration process, for example, including those typical of magnetic reconnection in solar flares, but also emission in the strong magnetic fields of neutron stars and white dwarfs. It detects scattering in asymmetric structures such as accretion disks and columns, and in the so-called molecular torus and ionization cones. In addition, it allows fundamental physics in regimes of gravity and of magnetic field intensity not accessible to experiments on the Earth to be probed. Finally, models that describe fundamental interactions (e.g. quantum gravity and the extension of the Standard Model) can be tested. We describe in this paper the X-ray Imaging Polarimetry Explorer (XIPE), proposed in June 2012 to the first ESA call for a small mission with a launch in 2017. The proposal was, unfortunately, not selected. To be compliant with this schedule, we designed the payload mostly with existing items. The XIPE proposal takes advantage of the completed phase A of POLARIX for an ASI small mission program that was cancelled, but is different in many aspects: the detectors, the presence of a solar flare polarimeter and photometer and the use of a light platform derived by a mass production for a cluster of satellites. XIPE is composed of two out of the three existing JET-X telescopes with two Gas Pixel Detectors (GPD) filled with a He-DME mixture at their focus. Two additional GPDs filled with a 3-bar Ar-DME mixture always face the Sun to detect polarization from solar flares. The Minimum Detectable Polarization of a 1 mCrab source reaches 14 in the 210 keV band in 105 s for pointed observations, and 0.6 for an X10 class solar flare in the 1535 keV energy band. The imaging capability is 24 arcsec Half Energy Width (HEW) in a Field of View of 14

  19. Microfocus/Polycapillary-Optic Crystallographic X-Ray System

    Science.gov (United States)

    Joy, Marshall; Gubarev, Mikhail; Ciszak, Ewa

    2005-01-01

    A system that generates an intense, nearly collimated, nearly monochromatic, small-diameter x-ray beam has been developed for use in macromolecular crystallography. A conventional x-ray system for macromolecular crystallography includes a rotating-anode x-ray source, which is massive (.500 kg), large (approximately 2 by 2 by 1 m), and power-hungry (between 2 and 18 kW). In contrast, the present system generates a beam of the required brightness from a microfocus source, which is small and light enough to be mounted on a laboratory bench, and operates at a power level of only tens of watts. The figure schematically depicts the system as configured for observing x-ray diffraction from a macromolecular crystal. In addition to the microfocus x-ray source, the system includes a polycapillary optic . a monolithic block (typically a bundle of fused glass tubes) that contains thousands of straight or gently curved capillary channels, along which x-rays propagate with multiple reflections. This particular polycapillary optic is configured to act as a collimator; the x-ray beam that emerges from its output face consists of quasi-parallel subbeams with a small angular divergence and a diameter comparable to the size of a crystal to be studied. The gap between the microfocus x-ray source and the input face of the polycapillary optic is chosen consistently with the focal length of the polycapillary optic and the need to maximize the solid angle subtended by the optic in order to maximize the collimated x-ray flux. The spectrum from the source contains a significant component of Cu K (photon energy is 8.08 keV) radiation. The beam is monochromatized (for Cu K ) by a nickel filter 10 m thick. In a test, this system was operated at a power of 40 W (current of 897 A at an accelerating potential of 45 kV), with an anode x-ray spot size of 41+/-2 microns. Also tested, in order to provide a standard for comparison, was a commercial rotating-anode x-ray crystallographic system with a

  20. Effective X-ray beam size measurements of an X-ray tube and polycapillary X-ray lens system using a scanning X-ray fluorescence method

    Energy Technology Data Exchange (ETDEWEB)

    Gherase, Mihai R., E-mail: mgherase@csufresno.edu; Vargas, Andres Felipe

    2017-03-15

    Size measurements of an X-ray beam produced by an integrated polycapillary X-ray lens (PXL) and X-ray tube system were performed by means of a scanning X-ray fluorescence (SXRF) method using three different metallic wires. The beam size was obtained by fitting the SXRF data with the analytical convolution between a Gaussian and a constant functions. For each chemical element in the wire an effective energy was calculated based on the incident X-ray spectrum and its photoelectric cross section. The proposed method can be used to measure the effective X-ray beam size in XRF microscopy studies.

  1. Diagnostics of laser-produced plasmas based on the analysis of intensity ratios of He-like ions X-ray emission

    Energy Technology Data Exchange (ETDEWEB)

    Ryazantsev, S. N. [Joint Institute for High Temperatures Russian Academy of Science (RAS), Moscow 125412, Russia; Faculty of Physics, M. V. Lomonosov Moscow State University, Moscow 119991, Russia; Skobelev, I. Yu. [Joint Institute for High Temperatures Russian Academy of Science (RAS), Moscow 125412, Russia; National Research Nuclear University MEPhI, Moscow 115409, Russia; Faenov, A. Ya. [Joint Institute for High Temperatures Russian Academy of Science (RAS), Moscow 125412, Russia; Institute for Academic Initiatives, Osaka University, Suita, Osaka 565-0871, Japan; Pikuz, T. A. [Joint Institute for High Temperatures Russian Academy of Science (RAS), Moscow 125412, Russia; Institute for Academic Initiatives, Osaka University, Suita, Osaka 565-0871, Japan; Higginson, D. P. [LULI-CNRS, École Polytechnique, CEA: Université Paris-Saclay, UPMC Univ Paris 06: Sorbonne Universités-F-91128 Palaiseau cedex, France; Lawrence Livermore National Laboratory, Livermore, California 94550, USA; Chen, S. N. [LULI-CNRS, École Polytechnique, CEA: Université Paris-Saclay, UPMC Univ Paris 06: Sorbonne Universités-F-91128 Palaiseau cedex, France; Institute of Applied Physics, 46 Ulyanov Street, 603950 Nizhny Novgorod, Russia; Revet, G. [LULI-CNRS, École Polytechnique, CEA: Université Paris-Saclay, UPMC Univ Paris 06: Sorbonne Universités-F-91128 Palaiseau cedex, France; Institute of Applied Physics, 46 Ulyanov Street, 603950 Nizhny Novgorod, Russia; Béard, J. [Laboratoire National des Champs magnétiques Intenses (LNCMI), UPR 3228, CNRS-Université Grenoble-Alpes (UGA)-Université Paul Sabatier (UPS)-Institut National des Sciences Appliquées (INSA), F-31400 Toulouse, France; Portugall, O. [Laboratoire National des Champs magnétiques Intenses (LNCMI), UPR 3228, CNRS-Université Grenoble-Alpes (UGA)-Université Paul Sabatier (UPS)-Institut National des Sciences Appliquées (INSA), F-31400 Toulouse, France; Soloviev, A. A. [Institute of Applied Physics, 46 Ulyanov Street, 603950 Nizhny Novgorod, Russia; Grum-Grzhimailo, A. N. [Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Moscow 119991, Russia; Fuchs, J. [LULI-CNRS, École Polytechnique, CEA: Université Paris-Saclay, UPMC Univ Paris 06: Sorbonne Universités-F-91128 Palaiseau cedex, France; Institute of Applied Physics, 46 Ulyanov Street, 603950 Nizhny Novgorod, Russia; Pikuz, S. A. [Joint Institute for High Temperatures Russian Academy of Science (RAS), Moscow 125412, Russia; National Research Nuclear University MEPhI, Moscow 115409, Russia

    2016-12-01

    In this paper, we detail the diagnostic technique used to infer the spatially resolved electron temperatures and densities in experiments dedicated to investigate the generation of magnetically collimated plasma jets. It is shown that the relative intensities of the resonance transitions in emitting He-like ions can be used to measure the temperature in such recombining plasmas. The intensities of these transitions are sensitive to the plasma density in the range of 1016–1020 cm-3 and to plasma temperature ranges from 10 to 100 eV for ions with a nuclear charge Zn ~10. We show how detailed calculations of the emissivity of F VIII ions allow to determine the parameters of the plasma jets that were created using ELFIE ns laser facility (Ecole Polytechnique, France). The diagnostic and analysis technique detailed here can be applied in a broader context than the one of this study, i.e., to diagnose any recombining plasma containing He-like fluorine ions.

  2. Diffractive X-ray Telescopes

    OpenAIRE

    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...

  3. Monochromatic plasma x-ray generator and its applications

    Science.gov (United States)

    Sato, Eiichi; Sagae, Michiaki; Takahashi, Kei; Ichimaru, Toshio; Aiba, Wataru; Kumagai, Shigehito; Hayasi, Yasuomi; Ido, Hideaki; Sakamaki, Kimio; Takayama, Kazuyoshi; Tamakawa, Yoshiharu

    1998-07-01

    The constructions of a plasma flash x-ray generator having a cold-cathode radiation tube and its application to soft radiography are described. The x-ray generator employs a high- voltage power supply, a low-impedance coaxial transmission line with a gap switch, a high-voltage condenser with a capacity of 0.2 (mu) F, a turbo-molecular pump, a thyristor pulser as a trigger device, and a flash x-ray tube. The high- voltage main condenser is charged up to 60 kV by the power supply, and the electric charges in the condenser are discharged to the tube after triggering the cathode electrode. The flash x-rays are then produced. The x-ray tube is a demountable triode which is connected to the turbo molecular pump with a pressure of approximately 1 mPa. This tube consists of a rod-shaped carbon cathode, a trigger electrode made from a copper wire, a stainless-steel vacuum chamber, insulators, a polyethylene terephthalate x-ray window, and two anode electrodes (targets) of molybdenum and silver. The space between the anode and cathode electrodes had a constant value of approximately 20 mm, and the trigger electrode is set in the center of the cathode electrode. As the electron flows from the cathode electrode are roughly converged to the target by the electric field in the tube, the plasma x-ray source which consists of metal ions and electrons is produced by the target evaporating. Because the bremsstrahlung spectra are absorbed by the monochromatic filter, K-series characteristic x-rays are obtained. Both the tube voltage and current displayed damped oscillations, and their peak values increased according to increases in the charging voltage. In the present work, the peak tube voltage was almost equivalent to the initial charging voltage of the main condenser, and the peak current had a value of about 25 kA with a charging voltage of 60 kV. When the charging voltage was increased, the intensities of the K-series characteristic x-rays increased. Next, the intensities

  4. The Imaging X-Ray Polarimetry Explorer (IXPE): Overview

    Science.gov (United States)

    O'Dell, Steve; Weisskopf, M.; Soffitta, P.; Baldini, L.; Bellazzini, R.; Costa, E.; Elsner, R.; Kaspi, V.; Kolodziejczak, J.; Latronico, L.; hide

    2017-01-01

    Mission background: Imaging x-ray polarimetry in 2–8 kiloelectronvolt band; NASA Astrophysics Small Explorer (SMEX) selected in 2017 January. Orbit: Pegasus-XL (airborne) launch in 2021, from Kwajalein; Equatorial circular orbit at greater than or approximately equal to 540 kilometers (620 kilometers, goal) altitude. Flight system: Spacecraft, payload structure, and integration by Ball Aerospace - Deployable payload boom from Orbital-ATK, under contract to Ball; X-ray Mirror Module Assemblies by NASA/MSFC; X-ray (polarization-sensitive) Instruments by IAPS/INAF (Istituto di Astrofisica e Planetologia Spaziali / Istituto Nazionale di Astrofisica) and INFN (Istituto Nazionale di Fisica Nucleare). Ground system: ASI (Agenzia Spaziale Italiana) Malindi ground station, with Singapore backup; Mission Operations Center at LASP (Laboratory for Atmospheric and Space Physics, University of Colorado); Science Operations Center at NASA/MSFC; Data archive at HEASARC (High Energy Astrophysics Science Archive Research Center), (NASA/GSFC), mirror at ASI Data Center. Science: Active galactic nuclei; Microquasars; Radio pulsars and pulsar wind nebulae; Supernova remnants; Magnetars; Accreting x-ray pulsars.

  5. Exotic x-ray emission from dense plasmas

    Science.gov (United States)

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

    2015-11-01

    Exotic x-ray emission from dense matter is identified as the complex high intensity satellite emission from autoionizing states of highly charged ions. Among a vast amount of possible transitions, double K-hole hollow ion (HI) x-ray emission K0L X → K1L X-1 + hν hollow is of exceptional interest due to its advanced diagnostic potential for matter under extreme conditions where opacity and radiation fields play important roles. Transient ab initio simulations identify intense short pulse radiation fields (e.g., those emitted by x-ray free electron lasers) as possible driving mechanisms of HI x-ray emission via two distinct channels: first, successive photoionization of K-shell electrons, second, photoionization followed by resonant photoexciation among various ionic charge states that are simultaneously present in high density matter. We demonstrated that charge exchange of intermixing inhomogenous plasmas as well as collisions driven by suprathermal electrons are possible mechanisms to populate HIs to observable levels in dense plasmas, particularly in high current Z-pinch plasmas and high intensity field-ionized laser produced plasmas. Although the HI x-ray transitions were repeatedly identified in many other cases of dense optical laser produced plasmas on the basis of atomic structure calculations, their origin is far from being understood and remains one of the last holy grails of high intensity laser-matter interaction.

  6. Comparing signal intensity and refraction sensitivity of double and single mask edge illumination lab-based x-ray phase contrast imaging set-ups

    Science.gov (United States)

    Kallon, G. K.; Diemoz, P. C.; Vittoria, F. A.; Basta, D.; Endrizzi, M.; Olivo, A.

    2017-10-01

    Double mask edge illumination (DM-EI) set-ups can detect differential phase and attenuation information from a sample. However, analytical separation of the two signals often requires acquiring two frames with inverted differential phase contrast signals. Typically, between these two acquisitions, the first mask is moved to create a different illumination condition. This can lead to potential errors which adversely affect the data collected. In this paper, we implement a single mask EI laboratory set-up that allows for a single shot retrieval of the differential phase and attenuation images, without the need for a high resolution detector or high magnification. As well as simplifying mask alignment, the advantages of the proposed set-up can be exploited in one of two ways: either the total acquisition time can be halved with respect to the DM-EI set-up or, for the same acquisition time, twice the statistics can be collected. In this latter configuration, the signal-to-noise ratio and contrast in the mixed intensity images, and the angular sensitivity of the two set-ups were compared. We also show that the angular sensitivity of the single mask set-up can be well approximated from its illumination curve, which has been modelled as a convolution between the source spatial distribution at the detector plane, the pre-sample mask and the detector point spread function (PSF). A polychromatic wave optics simulation was developed on these bases and benchmarked against experimental data. It can also be used to predict the angular sensitivity and contrast of any set-up as a function of detector PSF.

  7. Feeding tube placement: auscultatory method and x-ray agreement

    Directory of Open Access Journals (Sweden)

    Mariur Gomes Beghetto

    Full Text Available Objective: to evaluate the correlation between the auscultation test and X-ray when detecting the position of an enteral feeding tube. Methods: cross-sectional study in an intensive care unit in southern Brazil, in 2011. Clinical nurse and nurse researcher performed auscultation test recording the impressions regarding the placement of an enteral feeding tube in 80 patients. A doctor evaluated the X-ray. Kappa coefficient and PABAK reviewed the agreements. Results: The X-ray showed that 70% of the enteral tubes were in the stomach, 27.4% in the duodenum, 1.3% in the esophagus, and 1.3% in the right lung. There was a weak correlation between clinical nurses and nurse researchers (PABAK = 0.054; P = 0.103, clinical nurses and X-rays (PABAK = 0.188; P = 0.111 and nurse researchers and X-rays (PABAK = 0.128; P = 0.107 . The auscultation test did not detect two risk conditions, enteral feeding tube in the esophagus and the bronchus. Conclusion: the auscultation test showed little agreement with the X-ray on the enteral feeding tube location.

  8. Development and applications of X ray micro focusing optics

    CERN Document Server

    Ablett, J M

    2001-01-01

    The motivation for this thesis is the design and implementation of novel elliptical x-ray reflective micro-focusing optics. The advancement of x-ray micro-beam applications is a primary objective. Sputtering of a heavy metal onto a spherical substrate can produce the required elliptical profile, and the combination of two mirrors in an orthogonal arrangement can deliver intense x-ray micro-beams at an x-ray synchrotron source. It is believed that this new deposition process offers the best way of obtaining accurate elliptical profiles. Traditionally, reflective x-ray micro-focusing has been achieved by bending a smooth flat substrate, and the new deposition technique renders a much simpler experimental arrangement. Moreover, producing enhanced mirror profiles has the opportunity to provide sub-micron focused x-ray beams with larger apertures and longer working distances. Grazing-incidence rhodium-coated spherical substrates were employed to investigate a variety of systems, using several experimental methods:...

  9. 13th International Conference on X-Ray Lasers

    CERN Document Server

    Gautier, Julien; Ros, David; Zeitoun, Philippe

    2014-01-01

    These proceedings comprise of invited and contributed papers presented at the 13th International Conference on X-Ray Lasers (ICXRL 2012) which was held 11–15 June 2012 in Paris, in the famous Quartier Latin, inside the historical Center of Cordeliers. 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 towards practical devices and their applications are reported in these proceedings, including areas of research in plasma-based x-ray lasers, 4th generation accelerator-based sources and higher harmonic generation. Recent achievements related to the increase of the repetition rate up to 100 Hz and shorter wavelength collisional plasma-based soft x-ray lasers down to about 7 nm are presented. Seeding the amplifying plasma with a femtosecond high-order harmonic of infrared laser was fore...

  10. Automatic Identification of Solar X-Ray Bright Points in Hinode X-Ray Data

    Science.gov (United States)

    Adams, M. L.; Tennant, Allyn F.; Cirtain, J. W.

    2010-01-01

    We have automated a method that is used to find point sources in Chandra X-ray telescope data, to identify solar bright points in Hinode X-ray data. This tool, called lextrct, first identifies candidate sources that are brighter than the surrounding background. The algorithm also allows selected pixels to be excluded from the source-finding, thus allowing saturated pixels (from flares and/or active regions) to be ignored. We then use lextrct to fit the sources to two-dimensional, elliptical Gaussians. The size and orientation give an approximation of the shape of the bright points. We are in the process of analyzing observations through the Al_poly filter with a four-second exposure time, to obtain a catalogue of bright points, which will include their sizes, lifetimes, intensities, and position on the solar disk

  11. Perspectives of the lobster-eye telescope: The promising types of cosmic X-ray sources

    Science.gov (United States)

    Šimon, V.

    2017-07-01

    We show the astrophysical aspects of observing the X-ray sky with the planned lobster-eye telescope. This instrument is important because it is able to provide wide-field X-ray imaging. For the testing observations, we propose to include also X-ray binaries in which matter transfers onto the compact object (mostly the neutron star). We show the typical features of the long-term X-ray activity of such objects. Observing in the soft X-ray band is the most promising because their X-ray intensity is the highest in this band. Since these X-ray sources tend to concentrate toward the center of our Galaxy, several of them can be present in the field of view of the tested instrument.

  12. 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.

  13. Center for X-ray Optics, 1988

    Energy Technology Data Exchange (ETDEWEB)

    1989-04-01

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

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

    Science.gov (United States)

    ... for Educators Search English Español X-Ray Exam: Scoliosis KidsHealth / For Parents / X-Ray Exam: Scoliosis What's in this article? What It Is Why ... You Have Questions Print What It Is A scoliosis X-ray is a relatively safe and painless ...

  15. Techniques in X-ray Astronomy

    Indian Academy of Sciences (India)

    ray telescopes in space, leading to a veritable revolution. Stich telescopes require distortion free focusing of X-rays and the use of position sensitive X- ray detectors. In this article I shall describe the importance of X-ray imaging, the optical ...

  16. Sample Environment in Experiments using X-Ray Synchrotron Radiation

    DEFF Research Database (Denmark)

    Buras, B

    1984-01-01

    Modern electron (positron) storage rings are able to emit very intense X-ray radiation with a continuous spectrum extending to 0.1 A, from bending magnets and insertion devices (wavelength shifters and multipole wigglers). It can be used directly for white beam experiments and/or for monochromatic...... the design of the special environment, the experimental method used, and the X-ray beam tailored to the experiment with respect to wavelength. intensity, cross-section, divergence and polarization. This is discussed in some detail and illustrated by examples....

  17. Method for spatially modulating 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

    2015-03-10

    A method and apparatus are provided for spatially modulating X-rays or X-ray pulses using microelectromechanical systems (MEMS) based X-ray optics. A torsionally-oscillating MEMS micromirror and a method of leveraging the grazing-angle reflection property are provided to modulate X-ray pulses with a high-degree of controllability.

  18. NIKOLA TESLA AND THE X-RAY

    OpenAIRE

    Rade R. Babic

    2005-01-01

    After professor Wilhelm Konrad Röntgen published his study of an x-ray discovery (Academy Bulletin, Berlin, 08. 11. 1895.), Nikola Tesla published his first study of an x-ray on the 11th of March in 1896. (X-ray, Electrical Review). Until the 11th of August in 1897 he had published ten studies on this subject. All Tesla,s x-ray studies were experimental, which is specific to his work. Studying the nature of the x-ray, he established a new medical branch-radiology. He wrote:” There’s no doubt...

  19. X-ray Spectroscopy of Cooling Cluster

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-01-17

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

  20. Interaction of short x-ray pulses with low-Z x-ray optics materials at the LCLS free-electron laser

    NARCIS (Netherlands)

    Hau-Riege, S. P.; London, R. A.; Graf, A.; Baker, S. L.; Soufli, R.; Sobierajski, R.; Burian, T.; Chalupsky, J.; Juha, L.; Gaudin, J.; Krzywinski, J.; Moeller, S.; Messerschmidt, M.; Bozek, J.; Bostedt, C.

    2010-01-01

    Materials used for hard x-ray-free-electron laser (XFEL) optics must withstand high-intensity x-ray pulses. The advent of the Linac Coherent Light Source has enabled us to expose candidate optical materials, such as bulk B4C and SiC films, to 0.83 keV XFEL pulses with pulse energies between 1 mu J

  1. Structural evolution of regenerated silk fibroin under shear: Combined wide- and small-angle x-ray scattering experiments using synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Rossle, Manfred [European Molecular Biology Laboratory (EMBL), France; Panine, Pierre [European Synchrotron Radiation Facility (ESRF); Urban, Volker S [ORNL; Riekel, Christine [European Synchrotron Radiation Facility (ESRF)

    2004-04-01

    The structural evolution of regenerated Bombyx mori silk fibroin during shearing with a Couette cell has been studied in situ by synchrotron radiation small- and wide-angle x-ray scattering techniques. An elongation of fibroin molecules was observed with increasing shear rate, followed by an aggregation phase. The aggregates were found to be amorphous with {beta}-conformation according to infrared spectroscopy. Scanning x-ray microdiffraction with a 5 {micro}m beam on aggregated material, which had solidified in air, showed silk II reflections and a material with equatorial reflections close to the silk I structure reflections, but with strong differences in reflection intensities. This silk I type material shows up to two low-angle peaks suggesting the presence of water molecules that might be intercalated between hydrogen-bonded sheets.

  2. Toward active x-ray telescopes II

    Science.gov (United States)

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

    2012-10-01

    In the half century since the initial discovery of an astronomical (non-solar) x-ray source, the observation time required to achieve a given sensitivity has decreased by eight orders of magnitude. Largely responsible for this dramatic progress has been the refinement of the (grazing-incidence) focusing x-ray telescope, culminating with the exquisite subarcsecond imaging performance of the Chandra X-ray Observatory. The future of x-ray astronomy relies upon the development of x-ray telescopes with larger aperture areas (technologically challenging—requiring precision fabrication, alignment, and assembly of large areas (x-ray optics. This paper discusses relevant programmatic and technological issues and summarizes current progress toward active x-ray telescopes.

  3. On stellar X-ray emission

    Science.gov (United States)

    Rosner, R.; Golub, L.; Vaiana, G. S.

    1985-01-01

    Stellar X-ray astronomy represents an entirely new astronomical discipline which has emerged during the past five years. It lies at the crossroads of solar physics, stellar physics, and general astrophysics. The present review is concerned with the main physical problems which arise in connection with a study of the stellar X-ray data. A central issue is the extent to which the extrapolation from solar physics is justified and the definition (if possible) of the limits to such extrapolation. The observational properties of X-ray emission from stars are considered along with the solar analogy and the modeling of X-ray emission from late-type stars, the modeling of X-ray emission from early-type stars, the physics of stellar X-ray emission, stellar X-ray emission in the more general astrophysical context, and future prospects.

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

    OpenAIRE

    Sun, Tianxi; MacDonald, C.A.

    2013-01-01

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

  5. 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.

  6. Roadmap of ultrafast x-ray atomic and molecular physics

    Science.gov (United States)

    Young, Linda; Ueda, Kiyoshi; Gühr, Markus; Bucksbaum, Philip H.; Simon, Marc; Mukamel, Shaul; Rohringer, Nina; Prince, Kevin C.; Masciovecchio, Claudio; Meyer, Michael; Rudenko, Artem; Rolles, Daniel; Bostedt, Christoph; Fuchs, Matthias; Reis, David A.; Santra, Robin; Kapteyn, Henry; Murnane, Margaret; Ibrahim, Heide; Légaré, François; Vrakking, Marc; Isinger, Marcus; Kroon, David; Gisselbrecht, Mathieu; L’Huillier, Anne; Wörner, Hans Jakob; Leone, Stephen R.

    2018-02-01

    X-ray free-electron lasers (XFELs) and table-top sources of x-rays based upon high harmonic generation (HHG) have revolutionized the field of ultrafast x-ray atomic and molecular physics, largely due to an explosive growth in capabilities in the past decade. XFELs now provide unprecedented intensity (1020 W cm‑2) of x-rays at wavelengths down to ∼1 Ångstrom, and HHG provides unprecedented time resolution (∼50 attoseconds) and a correspondingly large coherent bandwidth at longer wavelengths. For context, timescales can be referenced to the Bohr orbital period in hydrogen atom of 150 attoseconds and the hydrogen-molecule vibrational period of 8 femtoseconds; wavelength scales can be referenced to the chemically significant carbon K-edge at a photon energy of ∼280 eV (44 Ångstroms) and the bond length in methane of ∼1 Ångstrom. With these modern x-ray sources one now has the ability to focus on individual atoms, even when embedded in a complex molecule, and view electronic and nuclear motion on their intrinsic scales (attoseconds and Ångstroms). These sources have enabled coherent diffractive imaging, where one can image non-crystalline objects in three dimensions on ultrafast timescales, potentially with atomic resolution. The unprecedented intensity available with XFELs has opened new fields of multiphoton and nonlinear x-ray physics where behavior of matter under extreme conditions can be explored. The unprecedented time resolution and pulse synchronization provided by HHG sources has kindled fundamental investigations of time delays in photoionization, charge migration in molecules, and dynamics near conical intersections that are foundational to AMO physics and chemistry. This roadmap coincides with the year when three new XFEL facilities, operating at Ångstrom wavelengths, opened for users (European XFEL, Swiss-FEL and PAL-FEL in Korea) almost doubling the present worldwide number of XFELs, and documents the remarkable progress in HHG capabilities

  7. Mutual control of X-rays and nuclear transitions

    Energy Technology Data Exchange (ETDEWEB)

    Gunst, Jonas Friedrich

    2015-12-14

    In the course of this Thesis the mutual control between X-rays and nuclear transitions is investigated theoretically. In the first Part, we study the nuclear photoexcitation with the highly brilliant and coherent X-ray free-electron lasers (XFELs). Apart from amplifying the direct resonant interaction with nuclear transitions, the super-intense XFEL can produce new states of matter like cold, high-density plasmas where secondary nuclear excitation channels may come into play, e.g., nuclear excitation by electron capture (NEEC). Our results predict that in the case of {sup 57}Fe targets secondary NEEC can be safely neglected, whereas it is surprisingly the dominating contribution (in comparison to the direct photoexcitation) for the XFEL-induced {sup 93m}Mo isomer triggering. Based on these case studies, we elaborate a general set of criteria to identify the prevailing excitation channel for a certain nuclear isotope. These criteria may be most relevant for future nuclear resonance experiments at XFEL facilities. On the opposite frontier, the interplay between single X-ray photons and nuclear transitions offer potential storage and processing applications for information science in their most compact form. In the second Part of this Thesis, we show that nuclear forward scattering off {sup 57}Fe targets can be employed to process polarization-encoded single X-rays via timed magnetic field rotations. Apart from the realization of logical gates with X-rays, the polarization encoding is used to design an X-ray quantum eraser scheme where the interference between scattering paths can be switched off and on in a controlled manner. Such setups may advance time-energy complementarity tests to so far unexplored parameter regimes, e.g., to the domain of X-ray quanta.

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

    Indian Academy of Sciences (India)

    Email: yprasad@cat.ernet.in. Abstract. The x-ray emission from slab targets of copper irradiated by Nd:glass laser (1.054 μm,. 5 and 15 ns) at intensities between 10. Ѕѕ and 10. ½. W/cm. ¾ has been studied. The x-ray emissions were monitored with the help of high quantum efficiency x-ray silicon photo diodes and vacuum.

  9. The impact of an ICME on the Jovian X-ray aurora

    OpenAIRE

    Dunn, William R.; Branduardi-Raymont, Graziella; Elsner, Ronald F.; Vogt, Marissa F.; Lamy, Laurent; Ford, Peter G.; Coates, Andrew J.; Gladstone, G. Randall; Jackman, Caitriona M.; Nichols, Jonathan D.; Rae, I. Jonathan; Varsani, Ali; Kimura, Tomoki; Hansen, Kenneth C.; Jasinski, Jamie M.

    2016-01-01

    International audience; We report the first Jupiter X-ray observations planned to coincide with an interplanetary coronal mass ejection (ICME). At the predicted ICME arrival time, we observed a factor of ∼8 enhancement in Jupiter's X-ray aurora. Within 1.5 h of this enhancement, intense bursts of non-Io decametric radio emission occurred. Spatial, spectral, and temporal characteristics also varied between ICME arrival and another X-ray observation two days later. Gladstone et al. (2002) disco...

  10. Resource Letter on Stimulated Inelastic X-ray Scattering at an XFEL

    Energy Technology Data Exchange (ETDEWEB)

    Patterson, Bruce D.; /SLAC

    2010-09-02

    At sufficient X-ray intensity, stimulated effects in inelastic scattering will become important. These coherent, non-linear optical phenomena may be used to impulsively produce a high degree of collective excitation in, for example, correlated electron materials, suitable for performing ultrafast time-resolved spectroscopy. This Resource Letter collects information on fundamental aspects of stimulated X-ray scattering and evaluates the prospect for successful experiments at a present or future X-ray free electron laser (XFEL) facility.

  11. 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.

  12. Optical, x-ray and microwave diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Tudisco, S.; Mascali, D.; Altana, C.; Anzalone, A.; Gammino, S.; Musumarra, A.; Musumeci, F.; Scordino, A. [INFN-LNS Via S. Sofia 62, 95123 Catania (Italy); Romano, F. P. [INFN-LNS Via S. Sofia 62, 95123 Catania (Italy); IBAM-CNR, Via Biblioteca 4, 95100 Catania (Italy); Tramontana, A. [INFN-LNS Via S. Sofia 62, 95123 Catania (Italy); Università di Catania, Dipartimento di Fisica e Astronomia, Via S. Sofia 64, Catania (Italy)

    2013-07-26

    Laser-driven ion acceleration is a new approach for the particles acceleration, which allows obtaining ion beams with unique properties, such as short burst duration, large particle number, small size source size, low transverse emittance. Currently, two main acceleration mechanisms have been identified and investigated: target normal sheath acceleration (TNSA) and radiation pressure acceleration (RPA). Electrons dynamics and energies are strongly coupled to these acceleration mechanisms and they can be investigated with optical and X-ray techniques. The main aim of these studies are the identification of few physical observables that can be directly correlated to the proton emission obtained (in terms of reproducibility and intensity) in operations with different target material and structure and laser-target interaction parameters.

  13. X-ray diffraction with novel geometry

    Energy Technology Data Exchange (ETDEWEB)

    Prokopiou, Danae [Department of Engineering and Applied Science Cranfield University, Shrivenham Campus, Swindon (United Kingdom); Rogers, Keith, E-mail: k.d.rogers@cranfield.ac.uk [Department of Engineering and Applied Science Cranfield University, Shrivenham Campus, Swindon (United Kingdom); Evans, Paul; Godber, Simon [Imaging Science Group, School of Science and Technology, Nottingham Trent University Clifton Campus, Nottingham (United Kingdom); Shackel, James [Department of Engineering and Applied Science Cranfield University, Shrivenham Campus, Swindon (United Kingdom); Dicken, Anthony [Imaging Science Group, School of Science and Technology, Nottingham Trent University Clifton Campus, Nottingham (United Kingdom)

    2014-01-21

    An innovative geometry for high efficiency harvesting of diffracted X-rays is explored. Further to previous work where planar samples were fixed normal to the primary axis, this work extends focal construct geometry (FCG), to samples randomly oriented with respect to the incident beam. The effect of independent sample rotation around two axes upon the scattering distributions was investigated in analytical, simulation and empirical manners. It was found that, although the profile of Bragg maxima were modified when the sample was rotated, high intensity diffraction data was still acquired. Modelling produced a good match to the empirical data and it was shown that the distortions caused by sample rotation were not severe and predictable even when sample rotations were large. The implications for this are discussed.

  14. Calculated x-ray powder diffraction patterns of plutonium

    Energy Technology Data Exchange (ETDEWEB)

    Roof, R.B.

    1977-10-01

    The X-ray powder diffraction patterns of the six phases of plutonium were calculated for Cu K..cap alpha../sub 1/ (lambda = 1.540598 A.) The results listed are 2 theta, sin/sup 2/ theta, d values, integrated intensities, and diffraction indices hkl.

  15. X-ray scattering studies of lanthanides magnetism

    DEFF Research Database (Denmark)

    McMorrow, D.; Bohr, Jakob; Gibbs, D.

    1999-01-01

    Interest in the applications of X-ray synchrotron radiation has grown rapidly during the last decade. At the present time, intense, ultra-bright synchrotron radiation is available on a routine basis from third-generation sources located in Europe (ESRF), North America (APS) and Japan (Spring8...

  16. Nuclear parameters from muonic and pionic x rays

    Energy Technology Data Exchange (ETDEWEB)

    Steffen, R M

    1980-01-01

    In view of the higher precision of the experimental data in measurements of the energies and relative intensities of the muonic and pionic x-ray transitions, the validity of the approximations made in extracting nuclear spectroscopic values from the raw data must be scrutinized more carefully if the reliability of the extracted parameters are to approach the accuracy of the experimental data. (GHT)

  17. Single atom identification by energy dispersive x-ray spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Lovejoy, T. C.; Dellby, N.; Krivanek, O. L. [Nion, 1102 8th St., Kirkland, Washington 98033 (United States); Ramasse, Q. M. [SuperSTEM Laboratory, STFC Daresbury, Keckwick Lane, Daresbury WA4 4AD (United Kingdom); Falke, M.; Kaeppel, A.; Terborg, R. [Bruker Nano GmbH, Schwarzschildstr. 12, 12489 Berlin (Germany); Zan, R. [School of Physics and Astronomy, University of Manchester, Manchester M13 9PL (United Kingdom)

    2012-04-09

    Using aberration-corrected scanning transmission electron microscope and energy dispersive x-ray spectroscopy, single, isolated impurity atoms of silicon and platinum in monolayer and multilayer graphene are identified. Simultaneously acquired electron energy loss spectra confirm the elemental identification. Contamination difficulties are overcome by employing near-UHV sample conditions. Signal intensities agree within a factor of two with standardless estimates.

  18. A metallic magnetic calorimeter dedicated to the spectrometry of L X-rays emitted by actinides

    Directory of Open Access Journals (Sweden)

    Rodrigues Matias

    2017-01-01

    Full Text Available Many actinides emit intense L X-rays consecutively to their decay. However the intensities of these X-rays are not well known: they are generally calculated with relatively large uncertainties and do not always agree with existing measurements. The latter ones are obtained with semiconductor spectrometers, but due to their insufficient energy resolution, these detectors are not able to separate the many X-ray lines and to give detailed emission intensities. So new measurements of precise and detailed L X-ray emission intensities are required. These would be beneficial on the one hand for the knowledge of the decay schemes and on the other hand as reference data for end-users of X-ray spectrometry. Therefore a spectrometer with a high energy resolution has been developed based on the technology of metallic magnetic calorimeters. The L X-ray spectra from 241Am and 210Pb decays show a FWHM energy resolution of 26 eV associated with a constant detection efficiency between 5 and 26 keV. With such performance, about 30 relative L X-ray intensities can be determined for 241Am and 210Pb. The measured emission intensities of L X-ray groups are compared with those published as obtained with conventional techniques; the good agreement between the data validated our technique.

  19. A MEMS-based high frequency x-ray chopper

    Energy Technology Data Exchange (ETDEWEB)

    Siria, A; Schwartz, W; Chevrier, J [Institut Neel, CNRS-Universite Joseph Fourier Grenoble, BP 166, F-38042 Grenoble Cedex 9 (France); Dhez, O; Comin, F [ESRF, 6 rue Jules Horowitz, F-38043 Grenoble Cedex 9 (France); Torricelli, G [Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom)

    2009-04-29

    Time-resolved x-ray experiments require intensity modulation at high frequencies (advanced rotating choppers have nowadays reached the kHz range). We here demonstrate that a silicon microlever oscillating at 13 kHz with nanometric amplitude can be used as a high frequency x-ray chopper. We claim that using micro-and nanoelectromechanical systems (MEMS and NEMS), it will be possible to achieve higher frequencies in excess of hundreds of megahertz. Working at such a frequency can open a wealth of possibilities in chemistry, biology and physics time-resolved experiments.

  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. X-ray pushing of a mechanical microswing.

    Science.gov (United States)

    Siria, A; Rodrigues, M S; Dhez, O; Schwartz, W; Torricelli, G; Ledenmat, S; Rochat, N; Auvert, G; Bikondoa, O; Metzger, T H; Wermeille, D; Felici, R; Comin, F; Chevrier, J

    2008-11-05

    We report here for the first time the combination of x-ray synchrotron light and a micro-electro-mechanical system (MEMS). We show how it is possible to modulate in real time a MEMS mass distribution to induce a nanometric and tunable mechanical oscillation. The quantitative experimental demonstration we present here uses periodic thermal dilatation of a Ge microcrystal attached to a Si microlever, induced by controlled absorption of an intensity modulated x-ray microbeam. The mechanism proposed can be envisaged either for the detection of small heat flux or for the actuation of a mechanical system.

  2. A MEMS-based high frequency x-ray chopper.

    Science.gov (United States)

    Siria, A; Dhez, O; Schwartz, W; Torricelli, G; Comin, F; Chevrier, J

    2009-04-29

    Time-resolved x-ray experiments require intensity modulation at high frequencies (advanced rotating choppers have nowadays reached the kHz range). We here demonstrate that a silicon microlever oscillating at 13 kHz with nanometric amplitude can be used as a high frequency x-ray chopper. We claim that using micro-and nanoelectromechanical systems (MEMS and NEMS), it will be possible to achieve higher frequencies in excess of hundreds of megahertz. Working at such a frequency can open a wealth of possibilities in chemistry, biology and physics time-resolved experiments.

  3. Screening in resonant X-ray emission of molecules

    DEFF Research Database (Denmark)

    Ågren, Hans; Luo, Yi; Gelmukhanov, Faris

    1996-01-01

    We explore the effects of screening in resonant X-ray emission from molecules by means of unconstrained multi-configurational self-consistent field optimizations of each state involved in the resonant and nonresonant X-ray processes. It is found that, although screening can produce shifts...... in transition energies of a few eV, its effect on the transition intensities is relatively minor. Using results from the investigated molecules, we find that the screening is quite dependent on the type of molecule - saturated versus unsaturated - and on the core site, but depends little on the particular core...

  4. X-ray monochromator for divergent beam radiography using conventional and laser-produced x-ray sources

    Science.gov (United States)

    Schnopper, Herbert W.; Romaine, Suzanne E.; Krol, Andrzej

    2001-12-01

    We discuss technology that will produce a wide angle monochromatic beam of X-rays that appears to diverge from a virtual point source. Although our ideas are discussed in the context of dual energy subtraction angiography (DESA) that we are developing to operate in a clinical setting, they are widely adaptable to all applications of x-ray radiography. The best DESA analysis is obtained from X-ray images made in narrow energy bands just below and just above the I K-absorption edge. Our monochromator will be used to isolate these narrow bands to produce high contrast, high spatial resolution, ECG gated angiographic images. Emission lines, that have X-ray energies below (E-) and above (E+) the I K-absorption edge at 33.2 keV, are readily available. We have deposited variable d-spacing artificial crystals, called multilayers, on optically flat, very smooth substrates, to create narrow pass band X-ray monochromators centered on La and Ba K-emission lines. We will record (E-) and (E+) exposures on either photographic plates or, in the future, with energy sensitive pixelated arrays of solid state detectors. After a suitable normalization, the exposures will be subtracted to yield a high resolution, high contrast image of the I filled arteries. Although initial results will be obtained with conventional X-ray tubes, our goal is to couple the monochromators to a high intensity, laser produced, X-ray plasma. We will present early test data that shows the multilayer performance.

  5. Accretion Disks and Coronae in the X-Ray Flashlight

    Science.gov (United States)

    Degenaar, Nathalie; Ballantyne, David R.; Belloni, Tomaso; Chakraborty, Manoneeta; Chen, Yu-Peng; Ji, Long; Kretschmar, Peter; Kuulkers, Erik; Li, Jian; Maccarone, Thomas J.; Malzac, Julien; Zhang, Shu; Zhang, Shuang-Nan

    2018-02-01

    Plasma accreted onto the surface of a neutron star can ignite due to unstable thermonuclear burning and produce a bright flash of X-ray emission called a Type-I X-ray burst. Such events are very common; thousands have been observed to date from over a hundred accreting neutron stars. The intense, often Eddington-limited, radiation generated in these thermonuclear explosions can have a discernible effect on the surrounding accretion flow that consists of an accretion disk and a hot electron corona. Type-I X-ray bursts can therefore serve as direct, repeating probes of the internal dynamics of the accretion process. In this work we review and interpret the observational evidence for the impact that Type-I X-ray bursts have on accretion disks and coronae. We also provide an outlook of how to make further progress in this research field with prospective experiments and analysis techniques, and by exploiting the technical capabilities of the new and concept X-ray missions ASTROSAT, NICER, Insight-HXMT, eXTP, and STROBE-X.

  6. X-ray diffraction crystallography. Introduction, examples and solved problems

    Energy Technology Data Exchange (ETDEWEB)

    Waseda, Yoshio; Shinoda, Kozo [Tohoku Univ., Sendai (Japan). Inst. of Multidisciplinary Research for Advanced Materials; Matsubara, Eiichiro [Kyoto Univ. (Japan). Dept. of Materials Science and Engineering

    2011-07-01

    X-ray diffraction crystallography for powder samples is a well-established and widely used method. It is applied to materials characterization to reveal the atomic scale structure of various substances in a variety of states. The book deals with fundamental properties of X-rays, geometry analysis of crystals, X-ray scattering and diffraction in polycrystalline samples and its application to the determination of the crystal structure. The reciprocal lattice and integrated diffraction intensity from crystals and symmetry analysis of crystals are explained. To learn the method of X-ray diffraction crystallography well and to be able to cope with the given subject, a certain number of exercises is presented in the book to calculate specific values for typical examples. This is particularly important for beginners in X-ray diffraction crystallography. One aim of this book is to offer guidance to solving the problems of 90 typical substances. For further convenience, 100 supplementary exercises are also provided with solutions. Some essential points with basic equations are summarized in each chapter, together with some relevant physical constants and the atomic scattering factors of the elements. (orig.)

  7. Relations among stellar X-ray emission observed from Einstein, stellar rotation and bolometric luminosity

    Science.gov (United States)

    Pallavicini, R.; Golub, L.; Rosner, R.; Vaiana, G. S.; Ayres, T.; Linsky, J. L.

    1981-01-01

    The correlation between observed stellar X-ray luminosities, bolometric luminosities, and projected rotational velocities for stars of various spectral types and luminosity classes are determined. Early type stars (O3 to A5) have X-ray luminosities independent of rotational velocities, and correlating with bolometric luminosities. Late type stars of spectral type G to M have luminosities well correlated to equatorial rotational velocities, and are independent of luminosity class. The dependence of late type stars is found to be equivalent to a relation between the X-ray surface flux and the stellar angular velocity. F stars are intermediate with X-ray luminosities higher than would be predicted on the basis of the early type star relation, although lower than expected from the late type velocity dependence. The location of RS CVn stars as a class is also discussed, and it is found that the heating of late type stellar coronas does not result from direct conversion of ratational energy.

  8. Imaging X-ray Thomson Scattering Spectrometer Design and Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Gamboa, E.J. [University of Michigan; Huntington, C.M. [University of Michigan; Trantham, M.R. [University of Michigan; Keiter, P.A [University of Michigan; Drake, R.P. [University of Michigan; Montgomery, David [Los Alamos National Laboratory; Benage, John F. [Los Alamos National Laboratory; Letzring, Samuel A. [Los Alamos National Laboratory

    2012-05-04

    In many laboratory astrophysics experiments, intense laser irradiation creates novel material conditions with large, one-dimensional gradients in the temperature, density, and ionization state. X-ray Thomson scattering is a powerful technique for measuring these plasma parameters. However, the scattered signal has previously been measured with little or no spatial resolution, which limits the ability to diagnose inhomogeneous plasmas. We report on the development of a new imaging x-ray Thomson spectrometer (IXTS) for the Omega laser facility. The diffraction of x-rays from a toroidally-curved crystal creates high-resolution images that are spatially resolved along a one-dimensional profile while spectrally dispersing the radiation. This focusing geometry allows for high brightness while localizing noise sources and improving the linearity of the dispersion. Preliminary results are presented from a scattering experiment that used the IXTS to measure the temperature profile of a shocked carbon foam.

  9. High spatial resolution soft-x-ray microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Meyer-Ilse, W.; Medecki, H.; Brown, J.T. [Ernest Orlando Lawrence Berkeley National Lab., CA (United States)] [and others

    1997-04-01

    A new soft x-ray microscope (XM-1) with high spatial resolution has been constructed by the Center for X-ray Optics. It uses bending magnet radiation from beamline 6.1 at the Advanced Light Source, and is used in a variety of projects and applications in the life and physical sciences. Most of these projects are ongoing. The instrument uses zone plate lenses and achieves a resolution of 43 nm, measured over 10% to 90% intensity with a knife edge test sample. X-ray microscopy permits the imaging of relatively thick samples, up to 10 {mu}m thick, in water. XM-1 has an easy to use interface, that utilizes visible light microscopy to precisely position and focus the specimen. The authors describe applications of this device in the biological sciences, as well as in studying industrial applications including structured polymer samples.

  10. Ginga observations of dipping low mass X ray binaries

    Science.gov (United States)

    Smale, Alan P.; Mukai, Koji; Williams, O. Rees; Jones, Mark H.; Parmar, Arvind N.; Corbet, Robin H. D.

    1989-01-01

    Ginga observations of several low mass X ray binaries displaying pronounced dips of variable depth and duration in their X ray light curves are analyzed. The periodic occultation of the central X ray source by azimuthal accretion disk structure is considered. A series of spectra selected by intensity from the dip data from XB1916-053, are presented. The effects of a rapidly changing column density upon the spectral fitting results are modeled. EXO0748-676 was observed in March 1989 for three days. The source was found to be in a bright state with a 1 to 20 keV flux of 8.8 x 10 (exp -10) erg/sqcms. The data include two eclipses, observed with high time resolution.

  11. Tracking of azobenzene isomerization by X-ray emission spectroscopy.

    Science.gov (United States)

    Ebadi, H

    2014-09-11

    Cis-trans isomerizations are among the fundamental processes in photochemistry. In azobenzene or its derivatives this dynamics is, due to its reversibility, one of the reactions widely used in photostimulation of molecular motors or in molecular electronics. Though intensively investigated in the optical regime, no detailed study exists in the X-ray regime so far. Because the X-ray emission spectroscopy echoes the electronic structure sensitive to the geometry, this theoretical report based on the density functional theory and its time-dependent version presents different nitrogen K-edge X-ray emission spectra for cis and trans isomers with close interrelation to their electron configuration. Considering the spectrum along the isomerization path, these structural signatures can be utilized to probe the isomerization dynamics in the excited molecule. The scheme can further be generalized to the element specific photoreactions.

  12. The X-ray corona of Procyon

    Science.gov (United States)

    Schmitt, J. H. M. M.; Harnden, F. R., Jr.; Rosner, R.; Peres, G.; Serio, S.

    1985-01-01

    X-ray emission from the nearby system Procyon A/B (F5 IV + DF) was detected, using the IPC (Imaging Proportional Counter) on board the Einstein Observatory. Analysis of the X-ray pulse height spectrum suggests that the observed X-ray emission originates in Procyon A rather than in the white dwarf companion Procyon B, since the derived X-ray temperature, log T = 6.2, agrees well with temperatures found for quiescent solar X-ray emission. Modeling Procyon's corona with loops characterized by some apex temperature Tmax and emission length scale L, it is found that Tmax is well constrained, but L, and consequently the filling factor of the X-ray emitting gas, are essentially unconstrained even when EUV emission from the transition region is included in the analysis.

  13. 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.

  14. X-ray microdiffraction of biominerals.

    Science.gov (United States)

    Tamura, Nobumichi; Gilbert, Pupa U P A

    2013-01-01

    Biominerals have complex and heterogeneous architectures, hence diffraction experiments with spatial resolutions between 500 nm and 10 μm are extremely useful to characterize them. X-ray beams in this size range are now routinely produced at many synchrotrons. This chapter provides a review of the different hard X-ray diffraction and scattering techniques, used in conjunction with efficient, state-of-the-art X-ray focusing optics. These include monochromatic X-ray microdiffraction, polychromatic (Laue) X-ray microdiffraction, and microbeam small-angle X-ray scattering. We present some of the most relevant discoveries made in the field of biomineralization using these approaches. © 2013 Elsevier Inc. All rights reserved.

  15. Radiation safety in X-ray facilities

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-09-01

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

  16. Handbook of X-ray Astronomy

    Science.gov (United States)

    Arnaud, Keith; Smith, Randall; Siemiginowska, Aneta; Ellis, Richard; Huchra, John; Kahn, Steve; Rieke, George; Stetson, Peter B.

    2011-11-01

    Practical guide to X-ray astronomy for graduate students, professional astronomers and researchers. Presenting X-ray optics, basic detector physics and data analysis. It introduces the reduction and calibration of X-ray data, scientific analysis, archives, statistical issues and the particular problems of highly extended sources. The appendices provide reference material often required during data analysis. The handbook web page contains figures and tables: http://xrayastronomyhandbook.com/

  17. 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)

  18. 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

  19. 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° Thomson scattering between terawatt laser pulses and relativistic electrons. Using this technique, the author generated ~ 300 fs, 30 keV (0.4 Å) x-ray pulses. These x-ray pulses are absolutely synchronized with ultrashort laser pulses, allowing femtosecond optical pump/x-ray probe experiments to be performed. Using the right-angle Thomson scattering x-ray source, the author performed time-resolved x-ray diffraction studies of laser-perturbated InSb. These experiments revealed a delayed onset of lattice expansion. This delay is due to the energy relaxation from a dense electron-hole plasma to the lattice. The dense electron-hole plasma first undergoes Auger recombination, which reduces the carrier concentration while maintaining energy content. Longitudinal-optic (LO) phonon emission then couples energy to the lattice. LO phonon decay into acoustic phonons, and acoustic phonon propagation then causes the growth of a thermally expanded layer. Source characterization is instrumental in utilizing ultrashort x-ray pulses in time-resolved x-ray spectroscopies. By measurement of the electron beam diameter at the generation point, the pulse duration of the Thomson scattered x-rays is determined. Analysis of the Thomson scattered x-ray beam properties also provides a novel means of electron bunch characterization. Although the pulse duration is inferred for the Thomson scattering x-ray source, direct measurement is required for other x-ray pulse sources. A method based on the laser-assisted photoelectric effect (LAPE) has been demonstrated as a

  20. X-ray laser microscope apparatus

    Science.gov (United States)

    Suckewer, Szymon; DiCicco, Darrell S.; Hirschberg, Joseph G.; Meixler, Lewis D.; Sathre, Robert; Skinner, Charles H.

    1990-01-01

    A microscope consisting of an x-ray contact microscope and an optical microscope. The optical, phase contrast, microscope is used to align a target with respect to a source of soft x-rays. The source of soft x-rays preferably comprises an x-ray laser but could comprise a synchrotron or other pulse source of x-rays. Transparent resist material is used to support the target. The optical microscope is located on the opposite side of the transparent resist material from the target and is employed to align the target with respect to the anticipated soft x-ray laser beam. After alignment with the use of the optical microscope, the target is exposed to the soft x-ray laser beam. The x-ray sensitive transparent resist material whose chemical bonds are altered by the x-ray beam passing through the target mater GOVERNMENT LICENSE RIGHTS This invention was made with government support under Contract No. De-FG02-86ER13609 awarded by the Department of Energy. The Government has certain rights in this invention.

  1. Detector development for x-ray imaging

    Science.gov (United States)

    Mentzer, M. A.; Herr, D. A.; Brewer, K. J.; Ojason, N.; Tarpine, H. A.

    2010-02-01

    X-ray imaging requires unique optical detector system configuration for optimization of image quality, resolution, and contrast ratio. A system is described whereby x-ray photons from multiple anode sources create a series of repetitive images on fast-decay scintillator screens, from which an intensified image is transferred to a fast phosphor on a GEN II image intensifier and collected as a cineradiographic video with high speed digital imagery. The work addresses scintillator material formulation, flash x-ray implementation, image intensification, and high speed video processing and display. Novel determination of optimal scintillator absorption, x-ray energy and dose relationships, contrast ratio determination, and test results are presented.

  2. X-ray Observations of "Recycled" Pulsars

    Science.gov (United States)

    Bogdanov, Slavko

    2014-11-01

    The Chandra X-ray Observatory has been instrumental in establishing the X-ray properties of the Galactic population of rotation-powered ("recycled") millisecond pulsars. In this talk I will provide a summary of deep X-ray studies of globular cluster millisecond pulsars, as well as several nearby field millisecond pulsars. These include thermally-emitting recycled pulsars that may provide stringent constraints on the elusive neutron star equation of state, and so-called "redback" binary pulsars, which seem to sporadically revert to an X-ray binary-like state.

  3. Spectral brilliance of parametric X-rays at the FAST facility

    Energy Technology Data Exchange (ETDEWEB)

    Sen, Tanaji [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Seiss, Todd [Princeton Univ., Princeton, NJ (United States)

    2015-06-22

    We discuss the generation of parametric X-rays in the new photoinjector at the FAST (Fermilab Accelerator Science and Technology) facility in Fermilab. These experiments will be conducted in addition to channeling X-ray radiation experiments. The low emittance electron beam makes this facility a promising source for creating brilliant X-rays. We discuss the theoretical model and present detailed calculations of the intensity spectrum, energy and angular widths and spectral brilliance under different conditions. Furthermore, we report on expected results with parametric X-rays generated while under channeling conditions.

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

    Science.gov (United States)

    Pasham, Dheeraj R.; Strohmayer, Tod E.

    2013-01-01

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

  5. Hard X-ray Emission along the Z Track in GX 17+ 2

    Indian Academy of Sciences (India)

    -ray Timing Experiment (HEXTE) on board Rossi X-Ray Timing Explorer for Z source GX 17+2, we investigate the evolution of its PCA spectra and HEXTE spectra along a `Z' track on its hardness-intensity diagram. A hard X-ray tail is detected ...

  6. Recognition of binary x-ray systems utilizing the doppler effect

    Science.gov (United States)

    Novak, B. L.

    1980-01-01

    The possibility of recognizing the duality of a single class of X-ray systems utilizing the Doppler effect is studied. The procedure is based on the presence of a period which coincides with the orbital period at the intensity of the radiation in a fixed energy interval of the X-ray component of a binary system.

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

    Indian Academy of Sciences (India)

    2014-02-06

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

  8. 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.

  9. X-ray monitoring for astrophysical applications on Cubesat

    Science.gov (United States)

    Pina, L.; Hudec, R.; Inneman, A.; Cerna, D.; Jakubek, J.; Sieger, L.; Dániel, V.; Cash, W.; Mikulickova, L.; Pavlica, R.; Belas, E.; Polak, J.

    2015-05-01

    The primary objective of the project VZLUSAT-1 is the development, manufacturing, qualification and experimental verification of products and technologies in Earth orbit (IOD - In-Orbit Demonstration). This work addresses the issue of X-ray monitoring for astrophysical applications. The proposed wide-field optical system has not been used in space yet. The proposed novel approach is based on the use of 1D "Lobster eye" optics in combination with Timepix X-ray detector in the energy range 3 - 40 keV. The proposed project includes theoretical study and a functional sample of the Timepix X-ray detector with multifoil wide-field X-ray "Lobster eye" optics. Using optics to focus X-rays on a detector is the only solution in cases the intensity of impinging X-ray radiation is below the sensitivity of the detector, e.g. while monitoring astrophysical objects in space, or phenomena in the Earth's atmosphere. On board the functions and features of Radiation Hardened Composite Housing (RHCH), Solar panels based on composite substrate and Hollow Retro Reflector Array based on composite (HRRA) will be verified. To verify the properties of the developed products the satellite is equipped by Health Monitoring system (HM). HM system includes temperature, volatiles, radiation and mechanical properties sensors. The custom ADCS algorithms are being developed within the project. Given the number of IOD experiments and the necessary power the 1U CubeSat is equipped with Composite Deployable Panels (CDP) where HM panels and additional Solar panels are located. Satellite platform is assembled from commercial parts. Mission VZLUSAT-1 is planned for 6 months with launch in 2016.

  10. X-ray Emission from Solar Flares

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... 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 ...

  11. Instrumental technique in X-ray astronomy

    Science.gov (United States)

    Peterson, L. E.

    1975-01-01

    A detailed review of the development of instruments for X-ray astronomy is given with major emphasis on nonfocusing high-sensitivity counter techniques used to detect cosmic photons in the energy range between 0.20 and 300 keV. The present status of X-ray astronomy is summarized together with significant results of the Uhuru observations, and photon interactions of importance for the detection of X-rays in space are noted. The three principal devices used in X-ray astronomy (proportional, scintillation, and solid-state counters) are described in detail, data-processing systems for these devices are briefly discussed, and the statistics of nuclear counting as applied to X-ray astronomy is outlined analytically. Effects of the near-earth X-ray environment and atmospheric gamma-ray production on X-ray detection by low-orbit satellites are considered. Several contemporary instruments are described (proportional-counter systems, scintillation-counter telescopes, modulation collimators), and X-ray astronomical satellite missions are tabulated.

  12. X-ray Galaxy Clusters & Cosmology

    Science.gov (United States)

    Ettori, Stefano

    2011-09-01

    I present a summary of the four lectures given on these topics: (i) Galaxy Clusters in a cosmological context: an introduction; (ii) Galaxy Clusters in X-ray: how and what we observe, limits and prospects; (iii) X-ray Galaxy Clusters and Cosmology: total mass, gas mass & systematics; (iv) Properties of the ICM: scaling laws and metallicity.

  13. 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.

  14. The Beginnings of X-ray Crystallography

    Indian Academy of Sciences (India)

    IAS Admin

    Those were the days when Science was hovering around the wave–particle duality. William. Henry Bragg was toying with the idea that X-rays are particles and the observation made by Max von Laue that X-rays are diffracted by crystals could indeed lead to the understanding of crystal structures. On the other hand, his son, ...

  15. X-ray Measurements of Black Hole X-ray Binary Source GRS 1915+ ...

    Indian Academy of Sciences (India)

    tribpo

    X-ray Measurements of Black Hole X-ray Binary Source GRS. 1915+105 and the Evolution of Hard X-ray Spectrum. R. K. Manchanda, Tata Institute of Fundamental Research, Mumbai 400 005, India,. Received 1999 December 28; accepted 2000 February 9. Abstract. We report the spectral measurement of GRS 1915+105 ...

  16. Radiation dose in radius bone mineral density measurements using dual energy X-ray absorptiometry. Dosimetric method on scan beam

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, Ichiro; Ogata, Hiromitsu; Izumo, Yoshiro [Institute of Public Health, Tokyo (Japan); Ohkubo, Makoto; Kato, Akira

    2001-12-01

    Effective doses in radius bone mineral density measurements using dual energy X-ray absorptiometry (DEXA) were assessed with entrance beam intensity and X-ray absorption rate in organs. The X-ray entrance beam intensity was calculated from an energy fluence rate, and we demonstrated how to assess beam intensity by using thermoluminescent dosimeters (TLDs). The entrance beam energies were calculated from X-ray beam intensity in regard to beam sizes, scan areas, and scan times. The X-ray absorption rates were calculated by using X-ray absorption curves at bone mineral density measurements. The average tissue doses were determined by using reference female and men. Skin entrance intensity was 4 x 10{sup -4} [J/(m{sup 2}{center_dot}s)]. Skin entrance energies were 1-2 x 10{sup -3} [J] in proportion to wrist width. The effective dose was approximately 5 nSv. (author)

  17. 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-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...

  18. Hybrid scintillators for x-ray imaging

    Science.gov (United States)

    Bueno, Clifford; Rairden, Richard L.; Betz, Robert A.

    1996-04-01

    The objective of this effort is to improve x-ray absorption and light production while maintaining high spatial resolution in x-ray imaging phosphor screens. Our current target is to improve screen absorption efficiency and screen brightness by factors of 2 or greater over existing screens that have 10-1p/mm resolution. In this program, commercial phosphor screens are combined with highly absorbing, high-resolution scintillating fiber-optic (SFO) face plates to provide a hybrid sensor that exhibits superior spatial resolution, x-ray absorption, and brightness values over the phosphor material alone. These characteristics of hybrid scintillators can be adjusted to meet specific x-ray imaging requirements over a wide range of x-ray energy. This paper discusses the design, fabrication, and testing of a new series of hybrid scintillators.

  19. X-ray modeling for SMILE

    Science.gov (United States)

    Sun, T.; Wang, C.; Wei, F.; Liu, Z. Q.; Zheng, J.; Yu, X. Z.; Sembay, S.; Branduardi-Raymont, G.

    2016-12-01

    SMILE (Solar wind Magnetosphere Ionosphere Link Explorer) is a novel mission to explore the coupling of the solar wind-magnetosphere-ionosphere system via providing global images of the magnetosphere and aurora. As the X-ray imaging is a brand new technique applied to study the large scale magnetopause, modeling of the solar wind charge exchange (SWCX) X-ray emissions in the magnetosheath and cusps is vital in various aspects: it helps the design of the Soft X-ray Imager (SXI) on SMILE, selection of satellite orbits, as well as the analysis of expected scientific outcomes. Based on the PPMLR-MHD code, we present the simulation results of the X-ray emissions in geospace during storm time. Both the polar orbit and the Molniya orbit are used. From the X-ray images of the magnetosheath and cusps, the magnetospheric responses to an interplanetary shock and IMF southward turning are analyzed.

  20. SU-F-T-202: An Evaluation Method of Lifetime Attributable Risk for Comparing Between Proton Beam Therapy and Intensity Modulated X-Ray Therapy for Pediatric Cancer Patients by Averaging Four Dose-Response Models for Carcinoma Induction

    Energy Technology Data Exchange (ETDEWEB)

    Tamura, M; Shirato, H [Department of Radiation Oncology, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido (Japan); Ito, Y [Department of Biostatistics, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido (Japan); Sakurai, H; Mizumoto, M; Kamizawa, S [Proton Medical Research Center, University of Tsukuba, Tsukuba, Ibaraki (Japan); Murayama, S; Yamashita, H [Proton Therapy Division, Shizuoka Cancer Center Hospital, Nagaizumi, Shizuoka (Japan); Takao, S; Suzuki, R [Department of Medical Physics, Hokkaido University Hospital, Sapporo, Hokkaido (Japan)

    2016-06-15

    Purpose: To examine how much lifetime attributable risk (LAR) as an in silico surrogate marker of radiation-induced secondary cancer would be lowered by using proton beam therapy (PBT) in place of intensity modulated x-ray therapy (IMXT) in pediatric patients. Methods: From 242 pediatric patients with cancers who were treated with PBT, 26 patients were selected by random sampling after stratification into four categories: a) brain, head, and neck, b) thoracic, c) abdominal, and d) whole craniospinal (WCNS) irradiation. IMXT was re-planned using the same computed tomography and region of interest. Using dose volume histogram (DVH) of PBT and IMXT, the LAR of Schneider et al. was calculated for the same patient. The published four dose-response models for carcinoma induction: i) full model, ii) bell-shaped model, iii) plateau model, and ix) linear model were tested for organs at risk. In the case that more than one dose-response model was available, the LAR for this patient was calculated by averaging LAR for each dose-response model. Results: Calculation of the LARs of PBT and IMXT based on DVH was feasible for all patients. The mean±standard deviation of the cumulative LAR difference between PBT and IMXT for the four categories was a) 0.77±0.44% (n=7, p=0.0037), b) 23.1±17.2%,(n=8, p=0.0067), c) 16.4±19.8% (n=8, p=0.0525), and d) 49.9±21.2% (n=3, p=0.0275, one tailed t-test), respectively. The LAR was significantly lower by PBT than IMXT for the the brain, head, and neck region, thoracic region, and whole craniospinal irradiation. Conclusion: In pediatric patients who had undergone PBT, the LAR of PBT was significantly lower than the LAR of IMXT estimated by in silico modeling. This method was suggested to be useful as an in silico surrogate marker of secondary cancer induced by different radiotherapy techniques. This research was supported by the Translational Research Network Program, JSPS KAKENHI Grant No. 15H04768 and the Global Institution for

  1. Grid-enhanced X-ray coded aperture microscopy with polycapillary optics.

    Science.gov (United States)

    Sowa, Katarzyna M; Last, Arndt; Korecki, Paweł

    2017-03-21

    Polycapillary devices focus X-rays by means of multiple reflections of X-rays in arrays of bent glass capillaries. The size of the focal spot (typically 10-100 μm) limits the resolution of scanning, absorption and phase-contrast X-ray imaging using these devices. At the expense of a moderate resolution, polycapillary elements provide high intensity and are frequently used for X-ray micro-imaging with both synchrotrons and X-ray tubes. Recent studies have shown that the internal microstructure of such an optics can be used as a coded aperture that encodes high-resolution information about objects located inside the focal spot. However, further improvements to this variant of X-ray microscopy will require the challenging fabrication of tailored devices with a well-defined capillary microstructure. Here, we show that submicron coded aperture microscopy can be realized using a periodic grid that is placed at the output surface of a polycapillary optics. Grid-enhanced X-ray coded aperture microscopy with polycapillary optics does not rely on the specific microstructure of the optics but rather takes advantage only of its focusing properties. Hence, submicron X-ray imaging can be realized with standard polycapillary devices and existing set-ups for micro X-ray fluorescence spectroscopy.

  2. Characteristic, parametric, and diffracted transition X-ray radiation for observation of accelerated particle beam profile

    Science.gov (United States)

    Chaikovska, I.; Chehab, R.; Artru, X.; Shchagin, A. V.

    2017-07-01

    The applicability of X-ray radiation for the observation of accelerated particle beam profiles is studied. Three types of quasi-monochromatic X-ray radiation excited by the particles in crystals are considered: characteristic X-ray radiation, parametric X-ray radiation, diffracted transition X-ray radiation. Radiation is collected at the right angle to the particle beam direction. It is show that the most intensive differential yield of X-ray radiation from Si crystal can be provided by characteristic radiation at incident electron energies up to tens MeV, by parametric radiation at incident electron energies from tens to hundreds MeV, by diffracted transition X-ray radiation at GeV and multi-GeV electron energies. Therefore these kinds of radiation are proposed for application to beam profile observation in the corresponding energy ranges of incident electrons. Some elements of X-ray optics for observation of the beam profile are discussed. The application of the DTR as a source of powerful tunable monochromatic linearly polarized X-ray beam excited by a multi-GeV electron beam on the crystal surface is proposed.

  3. Refraction contrast in X-ray imaging

    CERN Document Server

    Keyrilaeinen, J; Suortti, P

    2002-01-01

    A two-crystal diffractometer in the non-dispersive configuration is used for measurement of the effects of refraction in weakly absorbing test objects. Characteristic K alpha sub 1 radiation from a fine-focus X-ray tube with Mo anode is used. The probing beam is about 70 mu m wide and 3 mm high. The sample is placed between the monochromator and analyzer, and it is scanned through the beam. The analyzer is tuned to reflect at the low-angle slope, at the top, or at the high-angle slope of the rocking curve, when the sample is not in the beam. Refraction changes the angle of incidence on the analyzer causing changes in intensity. The observed intensity distributions are exactly reproduced by a calculation, where only the effects of refraction are included. The effects of in-beam interference are negligible or very small, which is also verified by changing the distance between the object and the detector.

  4. X-Ray Production by V1647 Ori During Optical Outbursts

    Science.gov (United States)

    Teets, William; Weintraub, David; Grosso, Nicolas; Principe, David; Kastner, Joel; Hamaguchi, Kenji; Richmond, Michael

    2011-01-01

    The pre-main-sequence (PMS) star V1647 Ori has recently undergone two optical/near-infrared (OIR) outbursts that are associated with dramatic enhancements in the stellar accretion rate. Our intensive X-ray monitoring of this object affords the opportunity to investigate whether and how the intense X-ray emission is related to PMS accretion activity. Our analysis of all 14 Chandra X-Ray Observatory observations of V1647 Ori demonstrates that variations in the X-ray luminosity of V1647 Ori are correlated with similar changes in the OIR brightness of this source during both (2003-2005 and 2008) eruptions, strongly supporting the hypothesis that accretion is the primary generation mechanism for the X-ray outbursts. Furthermore, the Chandra monitoring demonstrates that the X-ray spectral properties of the second eruption were strikingly similar to those of the 2003 eruption. We find that X-ray spectra obtained immediately following the second outburstduring which V1647 Ori exhibited high X-ray luminosities, high hardness ratios, and strong X-ray variabilityare well modeled as a heavily absorbed (N H 4 1022cm2), single-component plasma with characteristic temperatures (kT X 2-6keV) that are consistently too high to be generated via accretion shocks but are in the range expected for plasma heated by magnetic reconnection events. We also find that the X-ray absorbing column has not changed significantly throughout the observing campaign. Since the OIR and X-ray changes are correlated, we hypothesize that these reconnection events either occur in the accretion stream connecting the circumstellar disk to the star or in accretion-enhanced protostellar coronal activity.

  5. Toward Adaptive X-Ray Telescopes

    Science.gov (United States)

    O'Dell, Stephen L.; Atkins, Carolyn; Button, Tim W.; Cotroneo, Vincenzo; Davis, William N.; Doel, Peer; Feldman, Charlotte H.; Freeman, Mark D.; Gubarev, Mikhail V.; Kolodziejczak, Jeffrey J.; hide

    2011-01-01

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

  6. Multiple beam x-ray diffraction tomography

    Energy Technology Data Exchange (ETDEWEB)

    Kewish, C.M.; Davis, J.R.; Coyle, R.A. [Monash University, Clayton, VIC (Australia). Department of Physics

    1999-12-01

    Full text: X-ray diffraction computed tomography (XDT) is an imaging modality that utilises scattered x-rays to reconstruct an image. Since its inception in 1985, various detection scenarios and imaging techniques have been developed to demonstrate the accuracy and applicability of XDT. Many of the previous methods for measuring the scattered x-rays from an object utilise detectors that accept x-rays scattered from the entire length of the raypath through the object. The detector apertures must therefore have dimensions similar to the largest width of the scanned object. This creates a situation where the detected x-rays are not derived from a single scattering angle. A new method of scanning the x-rays scattered from an object is presented which allows quantitative determination of the spatial distribution of differential scattering cross section within a cross-sectional plane of the object. The new method incorporates a position sensitive detector and an arrangement of Soller slits. The acquired data represents both spatial and angular information. For each raypath through the object, a partial diffraction projection is measured at the off-axis detector and a set of diffraction projections is assembled by combining the diffracted signal from all rays through the object. A reconstruction strategy that accounts for attenuation of the primary beam and the scattered beam allows us to reconstruct a map of the differential scattering cross section in the sample for a given angle. Copyright (1999) Australian X-ray Analytical Association Inc. 3 refs.

  7. X-ray scattering signatures of {beta}-thalassemia

    Energy Technology Data Exchange (ETDEWEB)

    Desouky, Omar S. [Radiation Physics Department, National Center for Radiation Research and Technology (NCRRT) (Egypt); Elshemey, Wael M. [Biophysics Department, Faculty of Science, Cairo University (Egypt)], E-mail: waelelshemey@yahoo.com; Selim, Nabila S. [Radiation Physics Department, National Center for Radiation Research and Technology (NCRRT) (Egypt)

    2009-08-11

    X-ray scattering from lyophilized proteins or protein-rich samples is characterized by the presence of two characteristic broad peaks at scattering angles equivalent to momentum transfer values of 0.27 and 0.6 nm{sup -1}, respectively. These peaks arise from the interference of coherently scattered photons. Once the conformation of a protein is changed, these two peaks reflect such change with considerable sensitivity. The present work examines the possibility of characterizing the most common cause of hemolytic anaemia in Egypt and many Mediterranean countries; {beta}-thalassemia, from its X-ray scattering profile. This disease emerges from a genetic defect causing reduced rate in the synthesis of one of the globin chains that make up hemoglobin. As a result, structurally abnormal hemoglobin molecules are formed. In order to detect such molecular disorder, hemoglobin samples of {beta}-thalassemia patients are collected, lyophilized and measured using a conventional X-ray diffractometer. Results show significant differences in the X-ray scattering profiles of most of the diseased samples compared to control. The shape of the first scattering peak at 0.27 nm{sup -1}, in addition to the relative intensity of the first to the second scattering peaks, provides the most reliable signs of abnormality in diseased samples. The results are interpreted and confirmed with the aid of Fourier Transform Infrared (FTIR) spectroscopy of normal and thalassemia samples.

  8. Hard X-ray irradiation of cosmic silicate analogs: structural evolution and astrophysical implications

    Science.gov (United States)

    Gavilan, L.; Jäger, C.; Simionovici, A.; Lemaire, J. L.; Sabri, T.; Foy, E.; Yagoubi, S.; Henning, T.; Salomon, D.; Martinez-Criado, G.

    2016-03-01

    Context. Protoplanetary disks, interstellar clouds, and active galactic nuclei contain X-ray-dominated regions. X-rays interact with the dust and gas present in such environments. While a few laboratory X-ray irradiation experiments have been performed on ices, X-ray irradiation experiments on bare cosmic dust analogs have been scarce up to now. Aims: Our goal is to study the effects of hard X-rays on cosmic dust analogs via in situ X-ray diffraction. By using a hard X-ray synchrotron nanobeam, we seek to simulate cumulative X-ray exposure on dust grains during their lifetime in these astrophysical environments and provide an upper limit on the effect of hard X-rays on dust grain structure. Methods: We prepared enstatite (MgSiO3) nanograins, which are analogs to cosmic silicates, via the melting-quenching technique. These amorphous grains were then annealed to obtain polycrystalline grains. These were characterized via scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) before irradiation. Powder samples were prepared in X-ray transparent substrates and were irradiated with hard X-rays nanobeams (29.4 keV) provided by beamline ID16B of the European Synchrotron Radiation Facility (Grenoble). X-ray diffraction images were recorded in transmission mode, and the ensuing diffractograms were analyzed as a function of the total X-ray exposure time. Results: We detected the amorphization of polycrystalline silicates embedded in an organic matrix after an accumulated X-ray exposure of 6.4 × 1027 eV cm-2. Pure crystalline silicate grains (without resin) do not exhibit amorphization. None of the amorphous silicate samples (pure and embedded in resin) underwent crystallization. We analyze the evolution of the polycrystalline sample embedded in an organic matrix as a function of X-ray exposure. Conclusions: Loss of diffraction peak intensity, peak broadening, and the disappearance of discrete spots and arcs reveal the amorphization

  9. An Einstein Observatory X-ray survey of main-sequence stars with shallow convection zones

    Science.gov (United States)

    Schmitt, J. H. M. M.; Golub, L.; Harnden, F. R., Jr.; Maxson, C. W.; Rosner, R.; Vaiana, G. S.

    1985-01-01

    The results of an X-ray survey of bright late A and early F stars on the main B-V sequence between 0.1 and 0.5 are presented. All the stars were observed with the Einstein Observatory for a period of at least 500 seconds. The survey results show significantly larger X-ray luminosities for the sample binaries than for the single stars. It is suggested that the difference is due to the presence of multiple X-ray sources in binaries. It is shown that the X-ray luminosities for single stars increase rapidly with increasing color, and that the relation Lx/Lbol is equal to about 10 to the -7th does not hold for A stars. No correlation was found between X-ray luminosity and projected equatorial rotation velocity. It is argued on the basis of the observations that X-ray emission in the sample stars originated from coronae. The available observational evidence supporting this view is discussed.

  10. 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...... shall limit ourselves to a discussion of the interaction of an X-ray photon with an isolated atom, or rather with a single electron in a Hartree-Fock atom. Subsequent articles in this issue deal with more complicated - and interesting - forms of matter encompassing many atoms or molecules. To cite...

  11. X-ray Emission from Millisecond Pulsars

    Science.gov (United States)

    Zavlin, Vyacheslav

    2006-01-01

    Isolated (solitary or non-accreting) millisecond pulsars with observed X-ray emission can be divided in two distinct groups: those emitting nonthermal (magnetospheric) radiation and pulsars with the bulk of X-rays of a thermal origin, presumably emitted from small hot spots around the magnetic poles on the neutron star surface (polar caps). I will discuss properties of X-ray emission detected with Chandra and XMM-Newton from a number of millisecond pulsars, with emphasis on those of the thermal component, and compare them with predictions of radio pulsar models.

  12. 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

  13. Materials for refractive x-ray optics.

    Science.gov (United States)

    Lund, M W

    1997-01-01

    An X-ray lens using refraction has been proposed by Tomie, and demonstrated for 14 keV X-rays by Snigirev et al. This type of lens is made from a series of very weak lens elements. I calculate the properties of such lenses constructed of various chemical elements and compounds over the range of 1 to 30 keV. In general, I find that X-ray optics made from low density, low Z materials have the widest useful apertures, but require more lens elements than denser and higher Z materials.

  14. 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.

  15. The ROSAT X-ray Background Dipole

    OpenAIRE

    Plionis, M.; Georgantopoulos, I.

    1998-01-01

    We estimate the dipole of the diffuse 1.5 keV X-ray background from the ROSAT all-sky survey map of Snowden et al (1995). We first subtract the diffuse Galactic emission by fitting to the data an exponential scale height, finite radius, disk model. We further exclude regions of low galactic latitudes, of local X-ray emission (eg the North Polar Spur) and model them using two different methods. We find that the ROSAT X-ray background (XRB) dipole points towards $(l,b) ~ (288, 25) \\pm 19 degree...

  16. Observation of Reverse Saturable Absorption of an X-ray Laser

    Science.gov (United States)

    Cho, B. I.; Cho, M. S.; Kim, M.; Chung, H.-K.; Barbrel, B.; Engelhorn, K.; Burian, T.; Chalupský, J.; Ciricosta, O.; Dakovski, G. L.; Hájková, V.; Holmes, M.; Juha, L.; Krzywinski, J.; Lee, R. W.; Nam, Chang Hee; Rackstraw, D. S.; Toleikis, S.; Turner, J. J.; Vinko, S. M.; Wark, J. S.; Zastrau, U.; Heimann, P. A.

    2017-08-01

    A nonlinear absorber in which the excited state absorption is larger than the ground state can undergo a process called reverse saturable absorption. It is a well-known phenomenon in laser physics in the optical regime, but is more difficult to generate in the x-ray regime, where fast nonradiative core electron transitions typically dominate the population kinetics during light matter interactions. Here, we report the first observation of decreasing x-ray transmission in a solid target pumped by intense x-ray free electron laser pulses. The measurement has been made below the K -absorption edge of aluminum, and the x-ray intensity ranges are 1016 - 1017 W /cm2 . It has been confirmed by collisional radiative population kinetic calculations, underscoring the fast spectral modulation of the x-ray pulses and charge states relevant to the absorption and transmission of x-ray photons. The processes shown through detailed simulations are consistent with reverse saturable absorption, which would be the first observation of this phenomena in the x-ray regime. These light matter interactions provide a unique opportunity to investigate optical transport properties in the extreme state of matters, as well as affording the potential to regulate ultrafast x-ray free-electron laser pulses.

  17. Observation of Reverse Saturable Absorption of an X-ray Laser.

    Science.gov (United States)

    Cho, B I; Cho, M S; Kim, M; Chung, H-K; Barbrel, B; Engelhorn, K; Burian, T; Chalupský, J; Ciricosta, O; Dakovski, G L; Hájková, V; Holmes, M; Juha, L; Krzywinski, J; Lee, R W; Nam, Chang Hee; Rackstraw, D S; Toleikis, S; Turner, J J; Vinko, S M; Wark, J S; Zastrau, U; Heimann, P A

    2017-08-18

    A nonlinear absorber in which the excited state absorption is larger than the ground state can undergo a process called reverse saturable absorption. It is a well-known phenomenon in laser physics in the optical regime, but is more difficult to generate in the x-ray regime, where fast nonradiative core electron transitions typically dominate the population kinetics during light matter interactions. Here, we report the first observation of decreasing x-ray transmission in a solid target pumped by intense x-ray free electron laser pulses. The measurement has been made below the K-absorption edge of aluminum, and the x-ray intensity ranges are 10^{16} -10^{17}  W/cm^{2}. It has been confirmed by collisional radiative population kinetic calculations, underscoring the fast spectral modulation of the x-ray pulses and charge states relevant to the absorption and transmission of x-ray photons. The processes shown through detailed simulations are consistent with reverse saturable absorption, which would be the first observation of this phenomena in the x-ray regime. These light matter interactions provide a unique opportunity to investigate optical transport properties in the extreme state of matters, as well as affording the potential to regulate ultrafast x-ray free-electron laser pulses.

  18. Two methods for studying the X-ray variability

    NARCIS (Netherlands)

    Yan, Shu-Ping; Ji, Li; Méndez, Mariano; Wang, Na; Liu, Siming; Li, Xiang-Dong

    2016-01-01

    The X-ray aperiodic variability and quasi-periodic oscillation (QPO) are the important tools to study the structure of the accretion flow of X-ray binaries. However, the origin of the complex X-ray variability from X-ray binaries remains yet unsolved. We proposed two methods for studying the X-ray

  19. X-ray emission of exotic ions in dense plasmas

    Science.gov (United States)

    Rosmej, F. B.; Khaghani, D.; Dozières, M.; Dachicourt, R.; Šmíd, M.; Renner, O.

    2017-03-01

    Hollow ion X-ray emission has been observed in experiments studying interaction of heavy ion beams with solids and their occurrence has been ascribed to charge exchange processes occurring when highly charged ions interact with a metal surface. In high temperature high-density plasmas, like, e.g., high intensity laser produced plasmas or high current Z-pinches, numerous researchers have reported about "exotic" X-ray transitions of hollow ions: K0LX →K1LX-1+hνhollow. Although atomic structure calculations seem to confirm that measured line positions correspond to transitions in hollow ions, line identification is difficult and the observed high intensity remains a mystery (by orders of magnitude) up to present days.

  20. Line focus x-ray tubes—a new concept to produce high brilliance x-rays

    Science.gov (United States)

    Bartzsch, Stefan; Oelfke, Uwe

    2017-11-01

    Currently hard coherent x-ray radiation at high photon fluxes can only be produced with large and expensive radiation sources, such as 3rd generation synchrotrons. Especially in medicine, this limitation prevents various promising developments in imaging and therapy from being translated into clinical practice. Here we present a new concept of highly brilliant x-ray sources, line focus x-ray tubes (LFXTs), which may serve as a powerful and cheap alternative to synchrotrons and a range of other existing technologies. LFXTs employ an extremely thin focal spot and a rapidly rotating target for the electron beam which causes a change in the physical mechanism of target heating, allowing higher electron beam intensities at the focal spot. Monte Carlo simulations and numeric solutions of the heat equation are used to predict the characteristics of the LFXT. In terms of photon flux and coherence length, the performance of the line focus x-ray tube compares with inverse Compton scattering sources. Dose rates of up to 180 Gy s-1 can be reached in 50 cm distance from the focal spot. The results demonstrate that the line focus tube can serve as a powerful compact source for phase contrast imaging and microbeam radiation therapy. The production of a prototype seems technically feasible.

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

    Energy Technology Data Exchange (ETDEWEB)

    Mascali, David, E-mail: davidmascali@lns.infn.it; Castro, Giuseppe; Celona, Luigi; Neri, Lorenzo; Gammino, Santo [INFN–Laboratori Nazionali del Sud, Via S. Sofia 62, 95125 Catania (Italy); Biri, Sándor; Rácz, Richárd; Pálinkás, József [Institute for Nuclear Research (Atomki), Hungarian Academy of Sciences, Bem tér 18/c, H-4026 Debrecen (Hungary); Caliri, Claudia [INFN–Laboratori Nazionali del Sud, Via S. Sofia 62, 95125 Catania (Italy); Università degli Studi di Catania, Dip.to di Fisica e Astronomia, via Santa Sofia 64, 95123 Catania (Italy); Romano, Francesco Paolo [INFN–Laboratori Nazionali del Sud, Via S. Sofia 62, 95125 Catania (Italy); CNR, Istituto per i Beni Archeologici e Monumentali, Via Biblioteca 4, 95124 Catania (Italy); Torrisi, Giuseppe [INFN–Laboratori Nazionali del Sud, Via S. Sofia 62, 95125 Catania (Italy); Università Mediterranea di Reggio Calabria, DIIES, Via Graziella, I-89100 Reggio Calabria (Italy)

    2016-02-15

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

  2. 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...

  3. 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)

  4. 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....

  5. Chest X-Ray (Chest Radiography)

    Science.gov (United States)

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

  6. Microfabrication of hard x-ray lenses

    DEFF Research Database (Denmark)

    Stöhr, Frederik

    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...... developed. Inverse replica molding in PDMS of the CRLs was established as an effective way to circumvent the limitations AFM probes have when concave surfaces need to be characterized, e.g. due to the finite lengths of AFM probes. Four different x-ray optical components have been designed, manufactured...... of space for sample surroundings and ensure low-divergent and wide x-ray beams with narrow waists. Both results are substantial improvements to what was available at the start of this thesis work. The challenge of making x-ray objectives in silicon by interdigitation of lenslets alternately focusing...

  7. X-ray Optics Development at MSFC

    Science.gov (United States)

    Sharma, Dharma P.

    2017-01-01

    Development of high resolution focusing telescopes has led to a tremendous leap in sensitivity, revolutionizing observational X-ray astronomy. High sensitivity and high spatial resolution X-ray observations have been possible due to use of grazing incidence optics (paraboloid/hyperboloid) coupled with high spatial resolution and high efficiency detectors/imagers. The best X-ray telescope flown so far is mounted onboard Chandra observatory launched on July 23,1999. The telescope has a spatial resolution of 0.5 arc seconds with compatible imaging instruments in the energy range of 0.1 to 10 keV. The Chandra observatory has been responsible for a large number of discoveries and has provided X-ray insights on a large number of celestial objects including stars, supernova remnants, pulsars, magnetars, black holes, active galactic nuclei, galaxies, clusters and our own solar system.

  8. 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...

  9. 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 ...

  10. 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...

  11. 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...

  12. 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...

  13. Quantum optics with X-rays

    Science.gov (United States)

    Kuznetsova, Elena; Kocharovskaya, Olga

    2017-11-01

    The demonstration of strong coupling between two nuclear polariton modes in the X-ray spectral region using two coupled cavities each containing a thin layer of iron brings new opportunities for exploring quantum science.

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

    DEFF Research Database (Denmark)

    2012-01-01

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

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

    NARCIS (Netherlands)

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

    2007-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-03-01

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

  17. Simulating X-ray diffraction of textured films

    DEFF Research Database (Denmark)

    Breiby, Dag W.; Bunk, Oliver; Andreasen, Jens Wenzel

    2008-01-01

    Computationally efficient simulations of grazing-incidence X-ray diffraction (GIXD) are discussed, with particular attention given to textured thin polycrystalline films on supporting substrates. A computer program has been developed for simulating scattering from thin films exhibiting varying...... from the totally substrate-reflected beam ( two-beam approximation) and refraction effects are also included in the program, together with the geometrical intensity corrections associated with GIXD measurements. To achieve 'user friendliness' for scientists less familiar with diffraction...

  18. X-ray phase contrast imaging of biological samples using a betatron x-ray source generated in a laser wakefield accelerator

    Science.gov (United States)

    Chaulagain, U.; Bohacek, K.; Kozlova, M.; Nejdl, J.; Krus, M.; Horny, V.; Mahieu, B.; Ta-Phuoc, K.

    2017-05-01

    In a plasma wakefield accelerator, an intense laser pulse propagates in an under-dense plasma that drives a relativistic plasma wave in which electrons can be injected and accelerated to relativistic energies within a short distance. These accelerated electrons undergo betatron oscillation and emit a collimated X-ray beam along the direction of electron velocity. This X-ray source is characterised with a source size of the order of a micrometer, a pulse duration of the order of femtosecond, and with a high spectral brightness. This novel X-ray source provides an excellent imaging tool to achieve unprecedented high-resolution image through phase contrast imaging. The phase contrast technique has the potential to reveal structures which are invisible with the conventional absorption imaging. In the X-ray phase contrast imaging, the image contrast is obtained thanks to phase shifts induced on the X-rays passing through the sample. It involves the real part of refractive index of the object. Here we present high-resolution phase contrast X-ray images of two biological samples using laser-driven Betatron X-ray source.

  19. ASSESSMENT OF RESTORATION METHODS OF X-RAY IMAGES WITH EMPHASIS ON MEDICAL PHOTOGRAMMETRIC USAGE

    Directory of Open Access Journals (Sweden)

    S. Hosseinian

    2016-06-01

    Full Text Available Nowadays, various medical X-ray imaging methods such as digital radiography, computed tomography and fluoroscopy are used as important tools in diagnostic and operative processes especially in the computer and robotic assisted surgeries. The procedures of extracting information from these images require appropriate deblurring and denoising processes on the pre- and intra-operative images in order to obtain more accurate information. This issue becomes more considerable when the X-ray images are planned to be employed in the photogrammetric processes for 3D reconstruction from multi-view X-ray images since, accurate data should be extracted from images for 3D modelling and the quality of X-ray images affects directly on the results of the algorithms. For restoration of X-ray images, it is essential to consider the nature and characteristics of these kinds of images. X-ray images exhibit severe quantum noise due to limited X-ray photons involved. The assumptions of Gaussian modelling are not appropriate for photon-limited images such as X-ray images, because of the nature of signal-dependant quantum noise. These images are generally modelled by Poisson distribution which is the most common model for low-intensity imaging. In this paper, existing methods are evaluated. For this purpose, after demonstrating the properties of medical X-ray images, the more efficient and recommended methods for restoration of X-ray images would be described and assessed. After explaining these approaches, they are implemented on samples from different kinds of X-ray images. By considering the results, it is concluded that using PURE-LET, provides more effective and efficient denoising than other examined methods in this research.

  20. Assessment of Restoration Methods of X-Ray Images with Emphasis on Medical Photogrammetric Usage

    Science.gov (United States)

    Hosseinian, S.; Arefi, H.

    2016-06-01

    Nowadays, various medical X-ray imaging methods such as digital radiography, computed tomography and fluoroscopy are used as important tools in diagnostic and operative processes especially in the computer and robotic assisted surgeries. The procedures of extracting information from these images require appropriate deblurring and denoising processes on the pre- and intra-operative images in order to obtain more accurate information. This issue becomes more considerable when the X-ray images are planned to be employed in the photogrammetric processes for 3D reconstruction from multi-view X-ray images since, accurate data should be extracted from images for 3D modelling and the quality of X-ray images affects directly on the results of the algorithms. For restoration of X-ray images, it is essential to consider the nature and characteristics of these kinds of images. X-ray images exhibit severe quantum noise due to limited X-ray photons involved. The assumptions of Gaussian modelling are not appropriate for photon-limited images such as X-ray images, because of the nature of signal-dependant quantum noise. These images are generally modelled by Poisson distribution which is the most common model for low-intensity imaging. In this paper, existing methods are evaluated. For this purpose, after demonstrating the properties of medical X-ray images, the more efficient and recommended methods for restoration of X-ray images would be described and assessed. After explaining these approaches, they are implemented on samples from different kinds of X-ray images. By considering the results, it is concluded that using PURE-LET, provides more effective and efficient denoising than other examined methods in this research.

  1. Tidal tearing of circumstellar disks in Be/X-ray and gamma-ray binaries

    Science.gov (United States)

    Okazaki, Atsuo T.

    2017-11-01

    About one half of high-mass X-ray binaries host a Be star [an OB star with a viscous decretion (slowly outflowing) disk]. These Be/X-ray binaries exhibit two types of X-ray outbursts (Stella et al. 1986), normal X-ray outbursts (L X~1036-37 erg s-1) and occasional giant X-ray outbursts (L X > 1037 erg s-1). The origin of giant X-ray outbursts is unknown. On the other hand, a half of gamma-ray binaries have a Be star as the optical counterpart. One of these systems [LS I +61 303 (P orb = 26.5 d)] shows the superorbital (1,667 d) modulation in radio through X-ray bands. No consensus has been obtained for its origin. In this paper, we study a possibility that both phenomena are caused by a long-term, cyclic evolution of a highly misaligned Be disk under the influence of a compact object, by performing 3D hydrodynamic simulations. We find that the Be disk cyclically evolves in mildly eccentric, short-period systems. Each cycle consists of the following stages: 1) As the Be disk grows with time, the initially circular disk becomes eccentric by the Kozai-Lidov mechanism. 2) At some point, the disk is tidally torn off near the base and starts precession. 3) Due to precession, a gap opens between the disk base and mass ejection region, which allows the formation of a new disk in the stellar equatorial plane (see Figure 1). 4) The newly formed disk finally replaces the precessing old disk. Such a cyclic disk evolution has interesting implications for the long-term behavior of high energy emission in Be/X-ray and gamma-ray binaries.

  2. 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

  3. Nanofocusing Refractive X-Ray Lenses

    OpenAIRE

    Boye, Pit

    2010-01-01

    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. ...

  4. Lacquer polishing of x-ray optics.

    Science.gov (United States)

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

    1987-04-15

    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 ~0.2 mm. Tungsten films have been deposited on the lacquer coatings to provide highly efficient x-ray reflectivity.

  5. X-Ray Emission from Compact Sources

    Energy Technology Data Exchange (ETDEWEB)

    Cominsky, L

    2004-03-23

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

  6. Atomic Lithography: Forcing Epitaxial Growth Using X-Ray Standing Waves

    National Research Council Canada - National Science Library

    Falco, Charles

    1999-01-01

    In a remarkably short time we have made tremendous progress in both the design and construction of a unique "atomic lithography" deposition facility, and in observing effects of an intense x-ray beam...

  7. X-ray microbeams based on Kumakhov polycapillary optics and its ...

    Indian Academy of Sciences (India)

    ray radiation through bundles of monocapillaries of various configurations. The passage of radiation takes place because of the total external reflection of X-rays from the inner capillary walls. In this work, the basic characteristics of intense ...

  8. X-ray diagnostics of thorax diseases; Roentgendiagnostik von Thoraxerkrankungen. Von der Deskription zur Diagnose

    Energy Technology Data Exchange (ETDEWEB)

    Kulke, H.M. [Wuerzburg Univ. (Germany). Universitaetsklinikum

    2013-11-01

    The book on X-ray diagnostics of thorax diseases covers the following issues: diagnostic procedures, inflammatory thorax diseases, malign thorax diseases, heart and large blood vessels, hear insufficiency, pulmonary congestion, pulmonary edema, interstitial pulmonary diseases, intensive care and traumatology.

  9. Monochromatic Mammographic Imaging Using X-ray Polycapillary Optics

    National Research Council Canada - National Science Library

    Sugiro, Francisca

    2000-01-01

    .... Monochromatic x rays can be used to produce higher contrast images. Polycapillary x-ray optics technology can produce a highly parallel, monochromatic, x-ray beam from a conventional radiographic source...

  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. X-ray emission from normal stars

    Science.gov (United States)

    Rosner, Robert

    1990-01-01

    The paper addresses the potential for future X-ray missions to determine the fundamental cause of stellar X-ray emissions based on available results and existing analyses. The determinants of stellar X-ray emission are listed, and the relation of stellar X-ray emissions to the 'universal' activity-rotation connection is discussed. The specific rotation-activity connection for evolved stars is mentioned, and the 'decay' of stellar activity at the low-mass end of the main sequence is related to observational data. The data from Einstein and EXOSAT missions that correspond to these issues are found to be sparse, and more observational work is found to be necessary. Also, it is concluded that some issues need to be addressed, such as the X-ray dividing line in evolved stars and the absence of X-ray emission from dA stars. The related observational requirements and instrumental capabilities are given for each significant research focus.

  12. X-ray Studies of Planetary Nebulae

    Science.gov (United States)

    Montez, Rodolfo

    2017-10-01

    X-ray emission from planetary nebulae (PNe) provides unique insight on the formation and evolution of PNe. Past observations and the ongoing Chandra Planetary Nebulae Survey (ChanPlaNS) provide a consensus on the two types of X-ray emission detected from PNe: extended and compact point-like sources. Extended X-ray emission arises from a shocked ``hot bubble'' plasma that resides within the nebular shell. Cooler than expected hot bubble plasma temperatures spurred a number of potential solutions with one emerging as the likely dominate process. The origin of X-ray emission from compact sources at the location of the central star is less clear. These sources might arise from one or combinations of the following processes: self-shocking stellar winds, spun-up binary companions, and/or accretion, perhaps from mass transfer, PN fallback, or debris disks. In the discovery phase, X-ray studies of PNe have mainly focused on the origin of the various emission processes. New directions incorporate multi-wavelength observations to study the influence of X-ray emission on the rest of the electromagnetic spectrum.

  13. The universe in X-rays

    CERN Document Server

    Hasinger, Günther

    2008-01-01

    In the last 45 years, X-ray astronomy has become an integral part of modern astrophysics and cosmology. There is a wide range of astrophysical objects and phenomena, where X-rays provide crucial diagnostics. In particular they are well suited to study hot plasmas and matter under extreme physical conditions in compact objects. This book summarizes the present status of X-ray astronomy in terms of observational results and their astrophysical interpretation. It is written for students, astrophysicists as well a growing community of physicists interested in the field. An introduction including historical material is followed by chapters on X-ray astronomical instrumentation. The next two parts summarize in 17 chapters the present knowledge on various classes of X-ray sources in the galactic and extragalactic realm. While the X-ray astronomical highlights discussed in this book are mainly based on results from ROSAT, ASCA, RXTE, BeppoSAX, Chandra and XMM-Newton, a final chapter provides an outlook on observation...

  14. Images of the laser entrance hole from the static x-ray imager at NIF.

    Science.gov (United States)

    Schneider, M B; Jones, O S; Meezan, N B; Milovich, J L; Town, R P; Alvarez, S S; Beeler, R G; Bradley, D K; Celeste, J R; Dixit, S N; Edwards, M J; Haugh, M J; Kalantar, D H; Kline, J L; Kyrala, G A; Landen, O L; MacGowan, B J; Michel, P; Moody, J D; Oberhelman, S K; Piston, K W; Pivovaroff, M J; Suter, L J; Teruya, A T; Thomas, C A; Vernon, S P; Warrick, A L; Widmann, K; Wood, R D; Young, B K

    2010-10-01

    The static x-ray imager at the National Ignition Facility is a pinhole camera using a CCD detector to obtain images of Hohlraum wall x-ray drive illumination patterns seen through the laser entrance hole (LEH). Carefully chosen filters, combined with the CCD response, allow recording images in the x-ray range of 3-5 keV with 60 μm spatial resolution. The routines used to obtain the apparent size of the backlit LEH and the location and intensity of beam spots are discussed and compared to predictions. A new soft x-ray channel centered at 870 eV (near the x-ray peak of a 300 eV temperature ignition Hohlraum) is discussed.

  15. Images of the Laser Entrance Hole from the Static X-ray Imager at NIF

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, M; Jones, O; Meezan, N; Milovich, J; Town, R; Alvarez, S; Beeler, R; Bradley, D; Celeste, J; Dixit, S; Edwards, M; Haugh, M; Kalantar, D; Kline, J; Kyrala, G; Landen, O; MacGowan, B; Michel, P; Moody, J; Oberhelman, S; Piston, K; Pivovaroff, M; Suter, L; Teruya, A; Thomas, C; Vernon, S; Warrick, A; Widman, K; Wood, R; Young, B

    2010-05-04

    The Static X-ray Imager (SXI) at the National Ignition Facility (NIF) is a pinhole camera using a CCD detector to obtain images of hohlraum wall x-ray drive illumination patterns seen through the laser entrance hole (LEH). Carefully chosen filters combined with the CCD response allows recording images in the x-ray range of 3 to 5 keV with 60 {micro}m spatial resolution. The routines used to obtain the apparent size of the backlit LEH, and the location and intensity of beam spots are discussed and compared to predictions. A new soft x-ray channel centered at 870 eV (near the x-ray peak of a 300 eV temperature ignition hohlraum) is discussed.

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

    Science.gov (United States)

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

    2009-06-01

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

  17. Proposed New Accelerator Design for Homeland Security X-Ray Applications

    Energy Technology Data Exchange (ETDEWEB)

    Clayton, James [Varian Medical Systems, Inc., Palo Alto, CA 94304 (United States). Imaging Lab.; Shedlock, Daniel [Varian Medical Systems, Inc., Palo Alto, CA 94304 (United States). Imaging Lab.; Langeveld, Willem G.J. [Rapiscan Laboratories, Inc., Sunnyvale, CA 94085 (United States); Bharadwaj, Vinod [SLAC National Accelerator Lab., Menlo Park, CA (United States); Nosochkov, Yuri [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-08-07

    In the security and inspection market, there is a push towards highly mobile, reduced-dose active interrogation scanning and imaging systems to allow operation in urban environments. To achieve these goals, the accelerator system design needs to be smaller than existing systems. A smaller radiation exclusion zone may be accomplished through better beam collimation and an integrated, x-ray-source/detector-array assembly to allow feedback and control of an intensity-modulated x-ray source. A shaped low-Z target in the x-ray source can be used to generate a more forward peaked x-ray beam. Electron-beam steering can then be applied to direct the forward-peaked x rays toward areas in the cargo with high attenuation. This paper presents an exploratory study to identify components and upgrades that would be required to meet the desired specifications, as well as the best technical approach to design and build a prototype.

  18. Soft x-ray pulse length measurement by pump-probe absorption spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Tom, H.W.K. [Univ. of California, Riverside, CA (United States); Sher, M.H.; Mohideen, U.; Wood, O.R. II; Aumiller, G.D. [AT and T Bell Labs., Holmdel, NJ (United States); McIlrath, T.J. [Univ. of Maryland, College Park, MD (United States); Bokor, J.; Freeman, R.R. [AT and T Bell Labs., Murray Hill, NJ (United States); Sugar, J. [National Institute of Standards and Technology, Gaithersburg, MD (United States)

    1994-12-31

    The authors have demonstrated a system for subpicosecond, soft-x-ray continuum, pump-probe absorption spectroscopy. Using multiphoton ionization to abruptly change the x-ray absorption spectra of a gas, they have measured the temporal profile of laser-generated x-ray pulses near 90 eV. Although the x-ray pulses from a laser-generated plasma here were only as short as {approximately}20 psec, the technique is extendible to higher energy x-rays which will have pulse durations approaching 100 fsec. They also present the absorption spectrum of Kr ions produced under conditions of high intensity non-resonant multiphoton ionization. The spectra are identified with a fit to the Cowan code.

  19. Densitometry and temperature measurement of combustion gas by X-ray Compton scattering

    Energy Technology Data Exchange (ETDEWEB)

    Sakurai, Hiroshi, E-mail: sakuraih@gunma-u.ac.jp [Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515 (Japan); Kawahara, Nobuyuki [Okayama University, Tsushima-Naka 3, Okayama 700-8530 (Japan); Itou, Masayoshi [Japan Synchrotron Radiation Research Institute (JASRI), 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Tomita, Eiji [Okayama University, Tsushima-Naka 3, Okayama 700-8530 (Japan); Suzuki, Kosuke [Gunma University, 1-5-1 Tenjin-cho, Kiryu, Gunma 376-8515 (Japan); Sakurai, Yoshiharu [Japan Synchrotron Radiation Research Institute (JASRI), 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan)

    2016-02-17

    Measurement of combustion gas by high-energy X-ray Compton scattering is reported. Measurement of combustion gas by high-energy X-ray Compton scattering is reported. The intensity of Compton-scattered X-rays has shown a position dependence across the flame of the combustion gas, allowing us to estimate the temperature distribution of the combustion flame. The energy spectra of Compton-scattered X-rays have revealed a significant difference across the combustion reaction zone, which enables us to detect the combustion reaction. These results demonstrate that high-energy X-ray Compton scattering can be employed as an in situ technique to probe inside a combustion reaction.

  20. Compound refractive lenses as prefocusing optics for X-ray FEL radiation

    Energy Technology Data Exchange (ETDEWEB)

    Heimann, Philip, E-mail: paheim@slac.stanford.edu [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); MacDonald, Michael [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); University of Michigan, 500 South State Street, Ann Arbor, MI 48109 (United States); Nagler, Bob; Lee, Hae Ja; Galtier, Eric; Arnold, Brice; Xing, Zhou [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States)

    2016-02-17

    A prefocusing compound refractive lens was implemented for the Matter under Extreme Conditions Instrument at the Linac Coherent Light Source. A significant improvement in the beamline transmission was calculated and observed at 5 keV. The performance of X-ray free-electron laser beamlines may be limited by the angular aperture. Compound refractive lenses (CRLs) can be employed to prefocus the X-ray beam, thereby increasing the beamline transmission. A prefocusing CRL was implemented in the X-ray transport of the Matter under Extreme Conditions Instrument at the Linac Coherent Light Source. A significant improvement in the beamline transmission was calculated over the 3–10 keV photon energy range. At 5 keV, the relative X-ray intensity was measured and a factor of four increase was seen in the beamline transmission. The X-ray focus was also determined by the ablation imprint method.

  1. Observation of X-ray shadings in synchrotron radiation-total reflection X-ray fluorescence using a color X-ray camera

    Energy Technology Data Exchange (ETDEWEB)

    Fittschen, Ursula Elisabeth Adriane, E-mail: ursula.fittschen@chemie.uni-hamburg.de [Institut für Anorganische und Angewandte Chemie, Universität Hamburg, Martin-Luther-King-Platz 6, 20146 Hamburg (Germany); Menzel, Magnus [Institut für Anorganische und Angewandte Chemie, Universität Hamburg, Martin-Luther-King-Platz 6, 20146 Hamburg (Germany); Scharf, Oliver [IfG Institute for Scientific Instruments GmbH, Berlin (Germany); Radtke, Martin; Reinholz, Uwe; Buzanich, Günther [BAM Federal Institute of Materials Research and Testing, Berlin (Germany); Lopez, Velma M.; McIntosh, Kathryn [Los Alamos National Laboratory, Los Alamos, NM (United States); Streli, Christina [Atominstitut, TU Wien, Vienna (Austria); Havrilla, George Joseph [Los Alamos National Laboratory, Los Alamos, NM (United States)

    2014-09-01

    Absorption effects and the impact of specimen shape on TXRF analysis has been discussed intensively. Model calculations indicated that ring shaped specimens should give better results in terms of higher counts per mass signals than filled rectangle or circle shaped specimens. One major reason for the difference in signal is shading effects. Full field micro-XRF with a color X-ray camera (CXC) was used to investigate shading, which occurs when working with small angles of excitation as in TXRF. The device allows monitoring the illuminated parts of the sample and the shaded parts at the same time. It is expected that sample material hit first by the primary beam shade material behind it. Using the CXC shading could be directly visualized for the high concentration specimens. In order to compare the experimental results with calculation of the shading effect the generation of controlled specimens is crucial. This was achieved by “drop on demand” technology. It allows generating uniform, microscopic deposits of elements. The experimentally measured shadings match well with those expected from calculation. - Highlights: • Use of a color X-ray camera and drop on demand printing to diagnose X-ray shading • Specimens were obtained uniform and well-defined in shape and concentration by printing. • Direct visualization and determination of shading in such specimens using the camera.

  2. Stellar contributions to the diffuse soft X-ray background

    Science.gov (United States)

    Bookbinder, J.; Avni, Y.; Golub, L.; Rosner, R.; Vaiana, G.

    1981-01-01

    One of the results of the EINSTEIN/C.f.A. X-ray stellar survey was a determination of the contribution of the disk stellar population to the galactic component of the diffuse soft (0.28 - 1.0 keV) X-ray background. This analysis employed both binned and unbinned nonparametric statistical methods that have been developed by Avni, et al. (1980). These methods permitted the use of the information contained in both the 22 detections and 4 upper bounds on the luminosities of 26 dM stars in order to derive their luminosity function. Luminosity functions for earlier stellar types are not yet developed. For these earlier stellar types, the median luminosities as determined by Vaiana, et al., are used (1981), which underestimates their contribution to the background. We find that it is the M dwarfs that dominate the disk population stellar contribution to this background. To calculate the contribution of the stellar sources to the background, simple models both for the spatial distribution of the stars and for the properties of the intervening interstellar medium are used. A model is chosen in which all stellar classes have the same functional form for their spatial distribution: an exponentially decreasing distribution above the galactic equatorial plane, and a uniform distribution within the galactic plane for a region of several kiloparsecs centered on the Sun.

  3. X-rays as a probe of the Universe

    Indian Academy of Sciences (India)

    Table of contents. X-rays as a probe of the Universe · Probing the Universe ….. Flux = sT4 umax = 1011 T (in Kelvin) · History of x-ray astronomy · X-ray Production · X-ray spectra · Celestial sphere as seen by UHURU (1970) · Slide 8 · X-rays from accreting binary systems · Slide 10 · Neutron stars: Black Hole: · Primary X-ray ...

  4. [X-ray hardening correction for ICT in testing workpiece].

    Science.gov (United States)

    Peng, Guang-han; Cai, Xin-hua; Han, Zhong; Yang, Xue-heng

    2008-06-01

    Since energy spectrum of X-ray is polychromatic source in X-ray industrial computerized tomography, the variation of attenuation coefficient with energy leads to the lower energy of X-ray radiation being absorbed preferentially when X-ray is transmitting the materials. And the higher the energy of X-ray, the lower the attenuation coefficient of X-ray. With the increase in the X-ray transmission thickness, it becomes easier for the X-ray to transmit the matter. Thus, the phenomenon of energy spectrum hardening of X-ray takes place, resulting from the interaction between X-ray and the materials. This results in false images in the reconstruction of X-ray industrial computerized tomography. Therefore, hardening correction of energy spectrum of X-ray has to be done. In the present paper, not only is the hardening phenomenon of X-ray transmitting the materials analyzed, but also the relation between the X-ray beam sum and the transmission thickness of X-ray is discussed. And according to the Beer law and the characteristics of interaction when X-ray is transmitting material, and by getting the data of X-ray beam sum, the relation equation is fitted between the X-ray beam sum and X-ray transmission thickness. Then, the relation and the method of equivalence are carried out for X-ray beam sum being corrected. Finally, the equivalent and monochromatic attenuation coefficient fitted value for X-ray transmitting the material is reasoned out. The attenuation coefficient fitted value is used for product back-projection image reconstruction in X-ray industrial computerized tomography. Thus, the effect caused by X-ray beam hardening is wiped off effectively in X-ray industrial computerized tomography.

  5. Observations of the Crab Nebula with the Chandra X-Ray Observatory

    Science.gov (United States)

    Weisskopf, Martin C.

    2012-01-01

    The Crab Nebula and its pulsar has been the subject of a number of detailed observations with the Chandra X-ray Observatory. The superb angular resolution of Chandra s high-resolution telescope has made possible numerous remarkable results. Here we describe a number of specific studies of the Crab that I and my colleagues have undertaken. We discuss the geometry of the system, which indicates that the "inner X-ray ring", typically identified with the termination shock of the pulsar s particle wind, is most likely not in the equatorial plane of the pulsar. Other topics are the northern wisps and their evolution with time; the characterization of features in the jet to the southeast; pulse-phase spectroscopy and possible correlations with the features at other wavelengths, particularly the optical polarization; and a search for correlations of the X-ray flux with the recently-discovered gamma -ray flares.

  6. 3D Reconstruction from X-ray Fluoroscopy for Clinical Veterinary Medicine using Differential Volume Rendering

    Science.gov (United States)

    Khongsomboon, Khamphong; Hamamoto, Kazuhiko; Kondo, Shozo

    3D reconstruction from ordinary X-ray equipment which is not CT or MRI is required in clinical veterinary medicine. Authors have already proposed a 3D reconstruction technique from X-ray photograph to present bone structure. Although the reconstruction is useful for veterinary medicine, the thechnique has two problems. One is about exposure of X-ray and the other is about data acquisition process. An x-ray equipment which is not special one but can solve the problems is X-ray fluoroscopy. Therefore, in this paper, we propose a method for 3D-reconstruction from X-ray fluoroscopy for clinical veterinary medicine. Fluoroscopy is usually used to observe a movement of organ or to identify a position of organ for surgery by weak X-ray intensity. Since fluoroscopy can output a observed result as movie, the previous two problems which are caused by use of X-ray photograph can be solved. However, a new problem arises due to weak X-ray intensity. Although fluoroscopy can present information of not only bone structure but soft tissues, the contrast is very low and it is very difficult to recognize some soft tissues. It is very useful to be able to observe not only bone structure but soft tissues clearly by ordinary X-ray equipment in the field of clinical veterinary medicine. To solve this problem, this paper proposes a new method to determine opacity in volume rendering process. The opacity is determined according to 3D differential coefficient of 3D reconstruction. This differential volume rendering can present a 3D structure image of multiple organs volumetrically and clearly for clinical veterinary medicine. This paper shows results of simulation and experimental investigation of small dog and evaluation by veterinarians.

  7. X-ray diffraction-based electronic structure calculations and experimental x-ray analysis for medical and materials applications

    Science.gov (United States)

    Mahato, Dip Narayan

    This thesis includes x-ray experiments for medical and materials applications and the use of x-ray diffraction data in a first-principles study of electronic structures and hyperfine properties of chemical and biological systems. Polycapillary focusing lenses were used to collect divergent x rays emitted from conventional x-ray tubes and redirect them to form an intense focused beam. These lenses are routinely used in microbeam x-ray fluorescence analysis. In this thesis, their potential application to powder diffraction and focused beam orthovoltage cancer therapy has been investigated. In conventional x-ray therapy, very high energy (˜ MeV) beams are used, partly to reduce the skin dose. For any divergent beam, the dose is necessarily highest at the entry point, and decays exponentially into the tissue. To reduce the skin dose, high energy beams, which have long absorption lengths, are employed, and rotated about the patient to enter from different angles. This necessitates large expensive specialized equipment. A focused beam could concentrate the dose within the patient. Since this is inherently skin dose sparing, lower energy photons could be employed. A primary concern in applying focused beams to therapy is whether the focus would be maintained despite Compton scattering within the tissue. To investigate this, transmission and focal spot sizes as a function of photon energy of two polycapillary focusing lenses were measured. The effects of tissue-equivalent phantoms of different thicknesses on the focal spot size were studied. Scatter fraction and depth dose were calculated. For powder diffraction, the polycapillary optics provide clean Gaussian peaks, which result in angular resolution that is much smaller than the peak width due to the beam convergence. Powder diffraction (also called coherent scatter) without optics can also be used to distinguish between tissue types that, because they have different nanoscale structures, scatter at different angles

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

    Science.gov (United States)

    Noda, Daiji; Tokuoka, Atsushi; Katori, Megumi; Minamiyama, Yasuto; Yamashita, Kenji; Nishida, Satoshi; Hattori, Tadashi

    2012-07-01

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

  9. 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 (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 high......-quality X-ray absorption data and we report femtosecond time-resolved X-ray absorption near-edge spectroscopy (XANES) measurements of a spin-crossover system, iron(II) tris(2,2'-bipyridine) in water. The data indicate that the low-spin to high-spin transition can be modeled by single-exponential kinetics...

  10. Dual Energy X-Ray CT by Compton Scattering Hard X-Ray Source

    CERN Document Server

    Uesaka, Mitsuru; Kaneyasu, Tatsuo; Torikoshi, Masami

    2005-01-01

    We have developed a compact Compton scattering hard X-ray source at Nuclear Engineering Research Laboratory, University of Tokyo. The compact hard X-ray source can produce tunable monochromatic hard X-rays. The monochromatic hard X-rays are required in large field of medical and biological applications. We are planning to perform dual-energy X-ray CT, which enables us to measure atomic number Z distribution and electron density re distribution in a material. The hard X-ray source has an advantage to perform dual-energy X-ray CT. The X-ray energy can be changed quickly by introducing a fundamental frequency and a second harmonic frequency lasers. This quick energy change is indispensable to medical imaging and very difficult in a large SR light source and others. The information on the atomic number and electron density will be used for treatment plan in radiotherapy as well as for identification of materials in a nondestructive test. We examined applicability of the dual-energy X-ray CT for atomic number meas...

  11. X-ray detectors of the CAST experiment

    Science.gov (United States)

    Yildiz, S. C.

    2014-03-01

    CERN Axion Solar Telescope (CAST) is an experiment probing hypothetical particles: the axions, created in the solar core. Inside the transverse magnetic field of the CAST magnet, axions can be converted into x-rays, and be detected by four x-ray detectors at CAST. The expected x-ray signal in CAST is in 1-10 keV range, intensity depending strongly on the coupling constant of axion-photon conversion gaγ, which is expected to be low. This requires CAST to have detectors with very low background levels. The CAST Experiment makes use of three Micromesh Gaseous Structure (micromegas) detectors, which are gaseous detectors, derived from ideas of Multiwire Proportional Chambers (MWPC). CAST Micromegas detectors show perfect stability, good spatial and energy resolution. The intense study on Micromegas has enabled CAST to understand the nature of its background level, and improve it by a factor of 102 over ten years. New detector design, new readout system, better cosmic veto and addition of x-ray telescope will further improve the background in the next data taking of the experiment. The Charge-Coupled Device (CCD) of CAST is a pn-CCD detector with 200 × 64 pixels. The CAST CCD is coupled to an X-ray telescope, focusing all the parallel x-rays into a 9 mm diameter spot. The CCD will be replaced by the InGrid detector, a special manufactured micromegas detector. It is able to detect single electrons, and the low energy capabilities will open new frontiers on search of axions and other exotic particles. Another option is the Silicon Drift Detector (SDD), which is being tested in 2013, and has an energy threshold as low as 250 eV. The CAST experiment is the pioneering helioscope that excludes an important part of axion mass-coupling constant parameter space, and expects to exclude more in the following years. To succeed CAST, a new experiment, the International AXion Observatory (IAXO) is being designed and optimised, comprising the construction of a magnet specially built

  12. 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.

  13. Interaction of short x-ray pulses with low-Z x-ray optics materials at the LCLS free-electron laser.

    Science.gov (United States)

    Hau-Riege, S P; London, R A; Graf, A; Baker, S L; Soufli, R; Sobierajski, R; Burian, T; Chalupsky, J; Juha, L; Gaudin, J; Krzywinski, J; Moeller, S; Messerschmidt, M; Bozek, J; Bostedt, C

    2010-11-08

    Materials used for hard x-ray-free-electron laser (XFEL) optics must withstand high-intensity x-ray pulses. The advent of the Linac Coherent Light Source has enabled us to expose candidate optical materials, such as bulk B4C and SiC films, to 0.83 keV XFEL pulses with pulse energies between 1 μJ and 2 mJ to determine short-pulse hard x-ray damage thresholds. The fluence required for the onset of damage for single pulses is around the melt fluence and slightly lower for multiple pulses. We observed strong mechanical cracking in the materials, which may be due to the larger penetration depths of the hard x-rays.

  14. Determination of plutonium in nitric acid solutions using energy dispersive L X-ray fluorescence with a low power X-ray generator

    Energy Technology Data Exchange (ETDEWEB)

    Py, J. [Laboratoire Chrono-Environnement, UMR CNRS 6249, Université de Franche-Comté, 16 route de Gray, F-25030 Besançon (France); Commissariat à l’Énergie Atomique, Centre de Valduc, F-21120 Is-sur-Tille (France); Groetz, J.-E., E-mail: jegroetz@univ-fcomte.fr [Laboratoire Chrono-Environnement, UMR CNRS 6249, Université de Franche-Comté, 16 route de Gray, F-25030 Besançon (France); Hubinois, J.-C.; Cardona, D. [Commissariat à l’Énergie Atomique, Centre de Valduc, F-21120 Is-sur-Tille (France)

    2015-04-21

    This work presents the development of an in-line energy dispersive L X-ray fluorescence spectrometer set-up, with a low power X-ray generator and a secondary target, for the determination of plutonium concentration in nitric acid solutions. The intensity of the L X-rays from the internal conversion and gamma rays emitted by the daughter nuclei from plutonium is minimized and corrected, in order to eliminate the interferences with the L X-ray fluorescence spectrum. The matrix effects are then corrected by the Compton peak method. A calibration plot for plutonium solutions within the range 0.1–20 g L{sup −1} is given.

  15. Erratum: Creation of X-Ray Transparency of Matter by Stimulated Elastic Forward Scattering [Phys. Rev. Lett. 115 , 107402 (2015)

    Energy Technology Data Exchange (ETDEWEB)

    Stöhr, J.; Scherz, A.

    2016-01-06

    X-ray absorption by matter has long been described by the famous Beer-Lambert law. Here we show how this fundamental law needs to be modified for high-intensity coherent x-ray pulses, now available at x-ray free electron lasers, due to the onset of stimulated elastic forward scattering. We present an analytical expression for the modified polarization-dependent Beer-Lambert law for the case of resonant core-to-valence electronic transitions and incident transform limited x-ray pulses. Upon transmission through a solid, the absorption and dichroic contrasts are found to vanish with increasing x-ray intensity, with the stimulation threshold lowered by orders of magnitude through a super-radiative coherent effect. Our results have broad implications for the study of matter with x-ray lasers.

  16. Magnetic effects in resonant X-ray emission spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Grebennikov, V.I. E-mail: greben@imp.uran.ru

    2004-07-01

    A theoretical description for L{sub {alpha}} and L{sub {beta}} emission spectra recorded at different excitation photon energies gives the main spectral lines: a normal emission peak, with the constant energy, and a quasi-elastic peak that moves in energy scale when the incident photon energy changes. The intensity of the quasi-elastic peak is strongly controlled by valence electron excitations due to core-hole effects. Characteristic shake-up processes give rise to double lines in spectra. Applications of resonant inelastic soft X-ray scattering for studying magnetic systems are discussed. Emission spectra (as well as absorption spectra) show the magnetic dichroism when they are excited by the polarized incident X-ray radiation. But, the emission experiments contain information on the local magnetic moment values on excited atoms even in the case of depolarized incident radiation and in disordered magnetic states. The integral intensities ratio for L{sub {beta}}/L{sub {alpha}} lines in transition metal oxides are analyzed from this point of view. The similarity of experimental X-ray fluorescent spectra with emission spectra received by electron impacts allow us to conclude that in 3d-element compounds the high-energy electron impact transfers the 2p-electron into valence states with considerable probability.

  17. Imaging Macromolecules with X-ray laser pulses

    CERN Multimedia

    CERN. Geneva

    2017-01-01

    The short wavelength of X-rays allows us to resolve atoms, but in practise for biological materials the achievable resolution is limited by the destruction of the sample by the radiation that forms the image.  For over 100 years, the workaround to this problem of radiation damage has been to average signals from repeating copies of the object arranged in a large crystal.  It is now possible to overcome damage limits by using intense X-ray pulses that vaporise the sample, but which are short enough in duration to freeze any motion of the sample on the atomic scale.  With the advent of X-ray FELs we have been able to confirm this principle, and are now applying it to overcoming a major bottleneck for protein crystallography, which is the need for large well-diffracting crystals.  The intense pulses also open up opportunities to help solve the crystallographic phase problem.  In particular we have found that commonly-occurring disordered crystals that are usually not ...

  18. THz Pump and X-Ray Probe Development at LCLS

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, Alan S; /SLAC, LCLS; Durr, Hermann; /SIMES, Stanford /SLAC, PULSE; Lindenberg, Aaron; Stanford U., Materials Sci.Dept.; /SIMES, Stanford /SLAC, PULSE; Reis, David; /SIMES, Stanford /SLAC, PULSE /Stanford U., Dept. Appl. Phys.; Frisch, Josef; Loos, Henrik; Petree, Mark; /SLAC, LCLS; Daranciang, Dan; /Stanford U., Chem. Dept.; Fuchs, Matthias; /SLAC, PULSE; Ghimire, Shambhu; /SLAC, PULSE; Goodfellow, John; /Stanford U., Materials Sci. Dept.

    2011-11-08

    We report on measurements of broadband, intense, coherent transition radiation at terahertz frequencies, generated as the highly compressed electron bunches in Linear Coherent Light Source (LCLS) pass through a thin metal foil. The foil is inserted at 45{sup o} to the electron beam, 31 m downstream of the undulator. The THz emission passes downward through a diamond window to an optical table below the beamline. A fully compressed 350-pC bunch produces up to 0.5 mJ in a nearly half-cycle pulse of 50 fs FWHM with a spectrum peaking at 10 THz. We estimate a peak field at the focus of over 2.5 GV/m. A 20-fs Ti:sapphire laser oscillator has recently been installed for electro-optic measurements. We are developing plans to add an x-ray probe to this THz pump, by diffracting FEL x rays onto the table with a thin silicon crystal. The x rays would arrive with an adjustable time delay after the THz. This will provide a rapid start to user studies of materials excited by intense single-cycle pulses and will serve as a step toward a THz transport line for LCLS-II.

  19. Uhuru observations of the Norma X-ray burster

    Science.gov (United States)

    Grindlay, J.; Gursky, H.

    1976-01-01

    Four X-ray bursts consistent with a single source in Norma are reported which were discovered by reexamining Uhuru data obtained between 1970 and 1973. The temporal and spectral characteristics of the bursts are described and shown to be similar to those displayed by bursts from the globular cluster NGC 6224. An error box of the source location is given, and it is found that both the position and intensity of the four bursts are consistent with those of 10 bursts detected by the Vela satellites in 1976. It is concluded that the source is the same as that observed by the Vela and is an X-ray burster with characteristics similar to those of certain other bursters. XB 1608-52 is suggested as the designation of this burster, possible burst models are considered, and it is noted that the error box of the present source contains an identified globular cluster.

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

    Science.gov (United States)

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

    1973-01-01

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

  1. X-RAY EMISSION AND ABSORPTION FEATURES DURING AN ENERGETIC THERMONUCLEAR X-RAY BURST FROM IGR J17062-6143

    Energy Technology Data Exchange (ETDEWEB)

    Degenaar, N.; Miller, J. M. [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109 (United States); Wijnands, R.; Altamirano, D. [Astronomical Institute ' ' Anton Pannekoek' ' , University of Amsterdam, Postbus 94249, 1090 GE Amsterdam (Netherlands); Fabian, A. C., E-mail: degenaar@umich.edu [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 OHA (United Kingdom)

    2013-04-20

    Type-I X-ray bursts are thermonuclear explosions occurring in the surface layers of accreting neutron stars. These events are powerful probes of the physics of neutron stars and their surrounding accretion flow. We analyze a very energetic type-I X-ray burst from the neutron star low-mass X-ray binary IGR J17062-6143 that was detected with Swift on 2012 June 25. The light curve of the {approx_equal}18 minute long X-ray burst tail shows an episode of {approx_equal}10 minutes during which the intensity is strongly fluctuating by a factor of {approx_equal}3 above and below the underlying decay trend on a timescale of seconds. The X-ray spectrum reveals a highly significant emission line around {approx_equal}1 keV, which can be interpreted as an Fe-L shell line caused by the irradiation of cold gas. We also detect significant absorption lines and edges in the Fe-K band, which are strongly suggestive of the presence of hot, highly ionized gas along the line of sight. None of these features are present in the persistent X-ray spectrum of the source. The timescale of the strong intensity variations, the velocity width of the Fe-L emission line (assuming Keplerian motion), and photoionization modeling of the Fe-K absorption features each independently point to gas at a radius of {approx_equal} 10{sup 3} km as the source of these features. The unusual X-ray light curve and spectral properties could have plausibly been caused by a disruption of the accretion disk due to the super-Eddington fluxes reached during the X-ray burst.

  2. X-Ray Point-source Populations Constituting the Galactic Ridge X-Ray Emission

    Science.gov (United States)

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

    2013-03-01

    Apparently diffuse X-ray emission has been known to exist along the central quarter of the Galactic Plane since the beginning of X-ray astronomy; this is referred to as the Galactic Ridge X-ray emission (GRXE). Recent deep X-ray observations have shown that numerous X-ray point sources account for a large fraction of the GRXE in the hard band (2-8 keV). However, the nature of these sources is poorly understood. Using the deepest X-ray observations made in the Chandra bulge field, we present the result of a coherent photometric and spectroscopic analysis of individual X-ray point sources for the purpose of constraining their nature and deriving their fractional contributions to the hard-band continuum and Fe K line emission of the GRXE. Based on the X-ray color-color diagram, we divided the point sources into three groups: A (hard), B (soft and broad spectrum), and C (soft and peaked spectrum). The group A sources are further decomposed spectrally into thermal and non-thermal sources with different fractions in different flux ranges. From their X-ray properties, we speculate that the group A non-thermal sources are mostly active galactic nuclei and the thermal sources are mostly white dwarf (WD) binaries such as magnetic and non-magnetic cataclysmic variables (CVs), pre-CVs, and symbiotic stars, whereas the group B and C sources are X-ray active stars in flares and quiescence, respectively. In the log N-log S curve of the 2-8 keV band, the group A non-thermal sources are dominant above ≈10-14 erg cm-2 s-1, which is gradually taken over by Galactic sources in the fainter flux ranges. The Fe Kα emission is mostly from the group A thermal (WD binaries) and the group B (X-ray active stars) sources.

  3. 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.

  4. X-ray detectors for digital radiography

    Energy Technology Data Exchange (ETDEWEB)

    Yaffe, M.J.; Rowlands, J.A. [Imaging Research Program, Sunnybrook Health Science Centre, University of Toronto, Toronto, ON (Canada)

    1997-01-01

    Digital radiography offers the potential of improved image quality as well as providing opportunities for advances in medical image management, computer-aided diagnosis and teleradiology. Image quality is intimately inked to the precise and accurate acquisition of information from the x-ray beam transmitted by the patient, i.e. to the performance of the x-ray detector. Detectors for digital radiography must meet the needs of the specific radiological procedure where they will be used. Key parameters are partial resolution, uniformity of response, contrast sensitivity, dynamic range, acquisition speed and frame rate. The underlying physical considerations defining the performance of x-ray detectors for radiography will be reviewed. Some of the more promising existing and experimental detector technologies which may be suitable for digital radiography will be considered. Devices that can be employed in full-area detectors and also those more appropriate for scanning x-ray systems will be discussed. These include various approaches based on phosphor x-ray converters, where light quanta are produced as an intermediate stage, as well as direct -ray-to-charge conversion materials such as zinc cadmium telluride, amorphous selenium and crystalline silicon. (author)

  5. 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...

  6. Globular cluster X-ray sources

    Science.gov (United States)

    Pooley, D.

    We know from observations that globular clusters are very efficient catalysts in forming unusual binary systems, such as low-mass X-ray binaries (LMXBs), cataclysmic variables (CVs), and millisecond pulsars (MSPs), with formation rates per unit mass exceeding those in the Galactic disk by orders of magnitude. The high stellar densities in globular clusters trigger various dynamical interactions: exchange encounters, direct collisions, destruction of binaries, and tidal capture. This binary population is, in turn, critical to the stabilization of globular clusters against gravitational collapse; the long-term stability of a cluster is thought to depend on tapping into the gravitational binding energy of such close binaries. I will present an overview of the current state of globular cluster X-ray observations, as well as our work on deep Chandra observations of M4, where we reach some of the lowest X-ray luminosities in any globular cluster (comparable to the deep observations of 47 Tuc and NGC 6397). One of M4 X-ray sources previously classified as a white dwarf binary is likely a neutron star binary, and another X-ray source is a sub-subgiant, the nature of which is still unclear. skip=3pt

  7. X-ray irradiation of yeast cells

    Science.gov (United States)

    Masini, Alessandra; Batani, Dimitri; Previdi, Fabio; Conti, Aldo; Pisani, Francesca; Botto, Cesare; Bortolotto, Fulvia; Torsiello, Flavia; Turcu, I. C. Edmond; Allott, Ric M.; Lisi, Nicola; Milani, Marziale; Costato, Michele; Pozzi, Achille; Koenig, Michel

    1997-10-01

    Saccharomyces Cerevisiae yeast cells were irradiated using the soft X-ray laser-plasma source at Rutherford Laboratory. The aim was to produce a selective damage of enzyme metabolic activity at the wall and membrane level (responsible for fermentation) without interfering with respiration (taking place in mitochondria) and with nuclear and DNA activity. The source was calibrated by PIN diodes and X-ray spectrometers. Teflon stripes were chosen as targets for the UV laser, emitting X-rays at about 0.9 keV, characterized by a very large decay exponent in biological matter. X-ray doses to the different cell compartments were calculated following a Lambert-Bouguet-Beer law. After irradiation, the selective damage to metabolic activity at the membrane level was measured by monitoring CO2 production with pressure silicon detectors. Preliminary results gave evidence of pressure reduction for irradiated samples and non-linear response to doses. Also metabolic oscillations were evidenced in cell suspensions and it was shown that X-ray irradiation changed the oscillation frequency.

  8. Technical Development of Profile Measurement for the Soft X-Ray Via Compton Backward Scattering

    CERN Document Server

    Saito, Taku; Hayano, Hitoshi; Hidume, Kentaro; Kashiwagi, Shigeru; Kuroda, Ryunosuke; Minamiguchi, Shuichi; Oshima, Akihiro; Ueyama, Daisuke; Urakawa, Junji; Washio, Masakazu

    2005-01-01

    A compact X-ray source is called for such various fields as material development, biological science, and medical treatment. At Waseda University, we have already succeeded to generate the soft X-ray of the wavelength within so-called water window region (250-500eV) via Compton backward scattering between 1047nm Nd:YLF laser and 4.2MeV high quality electron beam. Although this method equips some useful characters, e.g. high intensity, short pulse, energy variableness, etc, the X-ray generating system is compact enough to fit in tabletop size. In the next step, there rises two principal tasks, that is, to make the soft X-ray intensity higher, and to progress X-ray profile measurement techniques as preliminary experiments for biomicroscopy. Specifically, we utilize two-pass amp for the former, and irradiate X-ray to a resist film which is previously exposed by UV lamp or get images with X-ray CCD for the latter. In this conference, we will show the experimental results and some future plans.

  9. The Operation Modes of Kharkov X-Ray Generator Based on Compton Scattering NESTOR

    Energy Technology Data Exchange (ETDEWEB)

    Bulyak, E.V.; Gladkikh, P.; Karnaukhov, I.M.; Mytsykov, A.; Shcherbakov, A.A.; Zelinsky, A.Y.; /Kharkov, KIPT; Tatchyn, R.; /SLAC, SSRL

    2005-05-09

    The results of theoretical and numerical considerations of linear Compton scattering are used to evaluate characteristics of X-rays produced by collision between a low emittance electron beam and intensive laser light in an X-ray generator NESTOR of NSC KIPT. Two main generation modes have been under consideration at preliminary NESTOR design. There are the operation mode for medicine 33.4 keV X-rays production using 43 Mev electron beam and Nd:YAG laser beam and higher energy X-rays production mode providing X-rays with energy up to 900 keV with 225 MeV electron beam and Nd:YAG laser beam. It was supposed to use an optical cavity for laser beam accumulation of about 2.6 m long and an interaction angle of about 3{sup o} in both operation modes. A few more operation modes provide possibility to expand operation range of NESTOR. Using interaction angle 10{sup o} and 150{sup o} along with optical resonator of 42 cm long and the second mode of laser light it is possible to produce X-rays in energy range from a few keV till 1.5 MeV. The intensity and spectral brightness of the X-rays is expected to be {approx} 10{sup 13} phot/s and {approx}10{sup 13} phot/s/mm{sup 2}/mrad{sup 2}/0.1%BW respectively.

  10. STELLAR WIND INDUCED SOFT X-RAY EMISSION FROM CLOSE-IN EXOPLANETS

    Energy Technology Data Exchange (ETDEWEB)

    Kislyakova, K. G.; Lammer, H. [Space Research Institute, Austrian Academy of Sciences, Graz (Austria); Fossati, L. [Argelander-Institut für Astronomie der Universität Bonn, Bonn (Germany); Johnstone, C. P. [Department of Astrophysics, University of Vienna, Vienna (Austria); Holmström, M. [Swedish Institute of Space Physics, Kiruna (Sweden); Zaitsev, V. V., E-mail: kristina.kislyakova@oeaw.ac.at [Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod (Russian Federation)

    2015-01-30

    In this Letter, we estimate the X-ray emission from close-in exoplanets. We show that the Solar/Stellar Wind Charge Exchange Mechanism (SWCX), which produces soft X-ray emission, is very effective for hot Jupiters. In this mechanism, X-ray photons are emitted as a result of the charge exchange between heavy ions in the solar wind and the atmospheric neutral particles. In the solar system, comets produce X-rays mostly through the SWCX mechanism, but it has also been shown to operate in the heliosphere, in the terrestrial magnetosheath, and on Mars, Venus, and the Moon. Since the number of emitted photons is proportional to the solar wind mass flux, this mechanism is not very effective for the solar system giants. Here we present a simple estimate of the X-ray emission intensity that can be produced by close-in extrasolar giant planets due to charge exchange with the heavy ions of the stellar wind. Using the example of HD 209458b, we show that this mechanism alone can be responsible for an X-ray emission of ≈10{sup 22} erg s{sup –1}, which is 10{sup 6} times stronger than the emission from the Jovian aurora. We discuss also the possibility of observing the predicted soft X-ray flux of hot Jupiters and show that despite high emission intensities they are unobservable with current facilities.

  11. Laser-pumped coherent x-ray free-electron laser

    Directory of Open Access Journals (Sweden)

    P. Sprangle

    2009-05-01

    Full Text Available In a laser-pumped x-ray free-electron laser (FEL an intense laser field replaces the magnetic wiggler field of a conventional FEL. Depending on the intensity and quality of both the electron beam and pump laser, the Thomson backscattered radiation can be coherently amplified. In a conventional FEL the generation of x rays requires electron beam energies in the multi-GeV range. In a laser-pumped x-ray FEL, electron beam energies in the multi-MeV range would be sufficient. To generate coherent x rays with this mechanism a number of physics and technology issues must be addressed. Foremost among these are the stringent requirements placed on the electron beam quality and brightness as well as on the pump laser. The seed radiation for the laser-pumped FEL is the laser-induced spontaneous radiation. The evolution of incoherent radiation into coherent radiation as well as the power gain lengths associated with the coherent x rays are analyzed and discussed. There is excellent agreement between our analytical results and GENESIS simulations for the radiated power, gain length, conversion efficiency, linewidth, and saturation length. These issues, as well as others, necessary to achieve coherent amplified x rays in a laser-pumped FEL are discussed. While a coherent x-ray source would have a number of attractive features, the requirements placed on both the electron beam and pump laser are extremely challenging.

  12. Luminescence imaging of water during irradiation of X-ray photons lower energy than Cerenkov- light threshold

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Seiichi; Koyama, Shuji; Komori, Masataka [Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine (Japan); Toshito, Toshiyuki [Department of Proton Therapy Physics, Nagoya Proton Therapy Center, Nagoya City West Medical Center (Japan)

    2016-10-01

    Luminescence imaging of water using X-ray photon irradiation at energy lower than maximum energy of ~200 keV is thought to be impossible because the secondary electrons produced in this energy range do not emit Cerenkov- light. Contrary to this consensus assumption, we show that the luminescence imaging of water can be achieved by X-ray irradiation at energy lower than 120 keV. We placed water phantoms on a table with a conventional X-ray imaging system, and luminescence images of these phantoms were measured with a high-sensitivity, cooled charge coupled device (CCD) camera during X-ray photon irradiation at energy below 120 keV. We also carried out such imaging of an acrylic block and plastic scintillator. The luminescence images of water phantoms taken during X-ray photon irradiation clearly showed X-ray photon distribution. The intensity of the X-ray photon images of the phantom increased almost proportionally to the number of X-ray irradiations. Lower-energy X-ray photon irradiation showed lower-intensity luminescence at the deeper parts of the phantom due to the higher X-ray absorption in the water phantom. Furthermore, lower-intensity luminescence also appeared at the deeper parts of the acrylic phantom due to its higher density than water. The intensity of the luminescence for water was 0.005% of that for plastic scintillator. Luminescence imaging of water during X-ray photon irradiation at energy lower than 120 keV was possible. This luminescence imaging method is promising for dose estimation in X-ray imaging systems.

  13. X-Ray Emission in the Heliosphere: Ion-Neutral Collisions as a Plasma Diagnostic

    Science.gov (United States)

    Cravens, Tom; Sibeck, David; Collier, MIchael

    2015-04-01

    The solar corona is the most powerful source of x-rays in the solar system but x-ray emission has also been observed from planets, including the Earth and Jupiter, from the Moon, from comets, and from interstellar gas entering the heliosphere. Astrophysical x-ray emission primarily comes from hot plasmas, such as in the million degree solar corona. The gas and plasma in planetary atmospheres are rather cold and the x-ray emission is driven by solar radiation and/or the solar wind. For example, x-rays from Venus come from the scattering and K-shell fluorescence of solar x-rays from the neutral atmosphere. Auroral x-ray emission at Earth and Jupiter is produced by energetic electron and ion precipitation from the magnetospheres into the atmospheres. Cometary and heliospheric x-ray emission is caused by charge transfer of high charge state solar wind ions (e.g., O7+, C6+,…) with neutral hydrogen and helium.An important source of solar system x-rays is the solar wind charge exchange (SWCX) mechanism. The solar wind originates in the hot solar corona and species heavier than helium (comprising about 0.1% of the gas) are highly-charged (e.g., O7+, C6+, Fe12+,….). Such ions undergo charge transfer collisions when they encounter neutral gas (e.g., cometary or interstellar gas or the Earth’s geocoronal hydrogen). The product ions are in highly-excited states and, subsequently, emit soft x-ray photons. The SWCX mechanism can explain the observed cometary x-ray emission and can also explain part of the soft x-ray background (the other part of which originates in the hot interstellar medium).The Earth has an extensive hot hydrogen exosphere, or geocorona, that is visible in scattered solar Lyman alpha. X-ray emission is produced in the magnetosheath due to the SWCX mechanism as the solar wind interacts with the exospheric gas. The most intense x-ray emission comes from the subsolar sheath region and from the cusp regions. Imaging of this emission by a spacecraft located

  14. Digital X-ray imager

    CERN Document Server

    LLNL &MedOptics Corporation

    1998-01-01

    The global objective of this cooperation was to lower the cost and improve the quality of breast health care in the United States. We planned to achieve it by designing a very high performance digital radiography unit for breast surgical specimen radiography in the operating room. These technical goals needed to be achieved at reasonable manufacturing costs to enable MedOptics to achieve high market penetration at a profit. Responsibility for overall project execution rested with MedOptics. MedOptics fabricated and demonstrated hardware, and selected components and handled the overall integration. After completion of this CRADA, MedOptics worked with collaborators to demonstrate clinical performance and utility. Finally, the company marketed the device. LLNL convened a multi-directorate expert panel for an intensive review of MedOptics point design. A written brief of panel conclusions and recommendations was prepared. In addition, LLNL was responsible for: computationally simulating the effects of varying so...

  15. Review of X-ray Tomography and X-ray Fluorescence Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Shear, Trevor A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-03-16

    This literature review will focus on both laboratory and synchrotron based X-ray tomography of materials and highlight the inner workings of these instruments. X-ray fluorescence spectroscopy will also be reviewed and applications of the tandem use of these techniques will be explored. The real world application of these techniques during the internship will also be discussed.

  16. X-ray photoelectron spectroscopy, high-resolution X-ray diffraction ...

    Indian Academy of Sciences (India)

    Powder X-ray diffraction studies were carried out on doped lithium niobate for phase identification. High-resolution X-ray diffraction technique was used to study the crystalline quality through full-width at half-maximum values. The refractive index values are more for doped samples than for pure sample as determined by ...

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

    Energy Technology Data Exchange (ETDEWEB)

    Takeichi, Yasuo, E-mail: yasuo.takeichi@kek.jp; Inami, Nobuhito; Ono, Kanta [High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba 305-0801 (Japan); Suga, Hiroki [Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526 (Japan); Takahashi, Yoshio [Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526 (Japan); The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)

    2016-01-28

    We report the design and performance of a compact scanning transmission X-ray microscope developed at the Photon Factory. Piezo-driven linear stages are used as coarse stages of the microscope to realize excellent compactness, mobility, and vibrational and thermal stability. An X-ray beam with an intensity of ∼10{sup 7} photons/s was focused to a diameter of ∼40 nm at the sample. At the soft X-ray undulator beamline used with the microscope, a wide range of photon energies (250–1600 eV) is available. The microscope has been used to research energy materials and in environmental sciences.

  18. Calibration of a high resolution grating soft x-ray spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Magee, E. W.; Dunn, J.; Brown, G. V.; Cone, K. V.; Park, J.; Porter, F. S.; Kilbourne, C. A.; Kelley, R. L.; Beiersdorfer, P.

    2010-10-01

    The calibration of the soft x-ray spectral response of a large radius of curvature, high resolution grating spectrometer (HRGS) with a back-illuminated charge-coupled device detector is reported. The instrument is cross-calibrated for the 10–50 Å waveband at the Lawrence Livermore National Laboratory electron beam ion trap (EBIT) x-ray source with the EBIT calorimeter spectrometer. The HRGS instrument is designed for laser-produced plasma experiments and is important for making high dynamic range measurements of line intensities, line shapes, and x-ray sources.

  19. The Soft X-ray Research instrument at the Linac Coherent Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Dakovski, Georgi L., E-mail: dakovski@slac.stanford.edu; Heimann, Philip; Holmes, Michael [Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Krupin, Oleg [Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); European XFEL, Notkestrasse 85, 22607 Hamburg (Germany); Minitti, Michael P.; Mitra, Ankush; Moeller, Stefan; Rowen, Michael; Schlotter, William F.; Turner, Joshua J. [Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States)

    2015-04-02

    A description of the Soft X-ray Research instrument (SXR) at the Linac Coherent Light Source is given. Recent scientific highlights illustrate the wide variety of experiments and detectors that can be accommodated at SXR. The Soft X-ray Research instrument provides intense ultrashort X-ray pulses in the energy range 280–2000 eV. A diverse set of experimental stations may be installed to investigate a broad range of scientific topics such as ultrafast chemistry, highly correlated materials, magnetism, surface science, and matter under extreme conditions. A brief description of the main instrument components will be given, followed by some selected scientific highlights.

  20. Versatile soft X-ray-optical cross-correlator for ultrafast applications

    Directory of Open Access Journals (Sweden)

    Daniel Schick

    2016-09-01

    eV up to the hard X-ray regime based on a molybdenum-silicon superlattice. The cross-correlation is done by probing intensity and position changes of superlattice Bragg peaks caused by photoexcitation of coherent phonons. This approach is applicable for a wide range of X-ray photon energies as well as for a broad range of excitation wavelengths and requires no external fields or changes of temperature. Moreover, the cross-correlator can be employed on a 10 ps or 100 fs time scale featuring up to 50% total X-ray reflectivity and transient signal changes of more than 20%.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-01-01

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

  2. New approach to breast tumor detection based on fluorescence x-ray analysis

    Directory of Open Access Journals (Sweden)

    Okuyama, Fumio

    2010-01-01

    Full Text Available A new technical approach to breast-tumor detection is proposed. The technique is based on fluorescence x-ray analysis, and can identify a miniature malignant tumor within the breast. The primary beam intensity needed in fluorescence x-ray analysis is on a lower order of magnitude than that used in mammography. Thus, the newly-proposed technique would enable detection of a still tiny breast cancer while dramatically lowering the radiation dose. Field-emission x-ray sources might be a key for translating this concept into a medical technique.

  3. 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

  4. X-ray optics developments at ESA

    DEFF Research Database (Denmark)

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

    2013-01-01

    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......) 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...... 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....

  5. 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.

  6. 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.

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

    Science.gov (United States)

    Jiang, Jinxing; Sakurai, Kenji

    2016-09-01

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

  8. Combined Effect of Low-Intensity Helium-Neon Laser and X-Ray Radiation on in Vivo Cellular Response of the Whole Blood and Lymphoid Organs in Mice.

    Science.gov (United States)

    Zaichkina, S I; Dyukina, A R; Rozanova, O M; Romanchenko, S P; Sirota, N P; Kuznetsova, E A; Simonova, N B; Sorokina, S S; Zakrzhevskaya, D T; Yusupov, V I; Bagratishvili, V N

    2016-09-01

    We studied the effect of exposure to helium-neon laser (dose range 0.16-50 mJ/cm2) on activation of natural protection reserve in mice using the adaptive response test. DNA comets method revealed a protective response manifested in DNA damage level in whole blood leukocytes of mice and in lymphoid organs by the thymus and spleen weight index; preexposure to laser did not induce the adaptive response. ROS level in the whole blood was assessed by the level of zymosan-induced luminol chemiluminescence. In mice subjected to adaptive laser irradiation in doses of 0.16-5 mJ/cm2 followed by X-ray irradiation in a dose of 1.5 Gy, the activation index calculated as the ratio of induced to spontaneous area of luminescence was by 1.4 times lower than that in non-irradiated animals, which attested to reduced ROSgeneration reserve capacity of neutrophils.

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

    Energy Technology Data Exchange (ETDEWEB)

    Stutman, Daniel; Finkenthal, Michael

    2017-11-21

    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.

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

    Science.gov (United States)

    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.

  11. Soft X-ray focusing Telescope aboard AstroSat

    DEFF Research Database (Denmark)

    Singh, K. P.; Dewangan, G. C.; Chandra, S.

    2017-01-01

    The Soft X-ray focusing Telescope (SXT) is a moderateresolution X-ray imaging spectrometer supplementing the ultraviolet and hard X-ray payloads for broadband studies of cosmic sources with AstroSat. Well suited for observing bright X-ray sources, SXT observations of nearby active galactic nuclei...

  12. Grazing Incidence X-ray Scattering and Diffraction

    Indian Academy of Sciences (India)

    ... Journals; Resonance – Journal of Science Education; Volume 19; Issue 12. Grazing Incidence X-ray Scattering and Diffraction. Jaydeep K Basu. General Article Volume 19 Issue 12 December ... Keywords. X-ray reflectivity; X-ray diffuse scattering; grazing incident diffraction; grazing incident; small angle X-ray scattering.

  13. 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...... 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....

  14. Tantalum/Copper X-Ray Targets

    Science.gov (United States)

    Waters, William J.; Edmonds, Brian

    1993-01-01

    Lewis Research Center developed unique solution to subsidiary problem of fabrication of x-ray target. Plasma spraying enabled fabrication of lightweight, high-performance targets. Power settings, atmosphere-control settings, rate of deposition, and other spraying parameters developed. Thin coats of tantalum successfully deposited on copper targets. Targets performed successfully in tests and satisfied all criteria expressed in terms of critical parameters. Significantly reduces projected costs of fabrication of targets and contributes to development of improved, long-lived, lightweight x-ray system.

  15. Studying Microquasars with X-Ray Polarimetry

    Directory of Open Access Journals (Sweden)

    Giorgio Matt

    2018-03-01

    Full Text Available Microquasars are Galactic black hole systems in which matter is transferred from a donor star and accretes onto a black hole of, typically, 10–20 solar masses. The presence of an accretion disk and a relativistic jet made them a scaled down analogue of quasars—thence their name. Microquasars feature prominently in the scientific goals of X-ray polarimeters, because a number of open questions, which are discussed in this paper, can potentially be answered: the geometry of the hot corona believed to be responsible for the hard X-ray emission; the role of the jet; the spin of the black hole.

  16. 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.

  17. X-ray fluorescence hologram data collection with a cooled avalanche photodiode

    CERN Document Server

    Hayashi, K; Matsubara, E I; Kishimoto, S; Mori, T; Tanaka, M

    2002-01-01

    A high counting rate X-ray detector with an appropriate energy resolution is desired for high quality X-ray fluorescence hologram measurements because a holographic pattern is detected as extremely small intensity variations of X-ray fluorescence on a large intensity background. A cooled avalanche photodiode (APD), which has about 10% energy resolution and is designed for a high counting rate, fits the above requirements. Reconstructed atomic images from experimental holograms using the APD system provide us a clear view of the first and second neighbor atoms around an emitter. The present result proved that a combination of this APD system and a synchrotron X-ray source enables us to measure a high quality hologram for a reasonable measurement time.

  18. Applications and measurements of polycapillary x-ray optics.

    Science.gov (United States)

    Macdonald, C A

    1996-01-01

    The recent invention of Kumakhov polycapillary x-ray and neutron optics has expanded the ways x-ray beams can be controlled. X rays incident on the interior of glass tubes at small angles can be guided down the tubes by total external reflection. Now, arrays of curved tapered capillaries can be used to focus, collimate, and filter x-ray radiation. Extensive research is being conducted on the performance and potential applications of these optics. Potential medical applications include mammography, digital energy subtraction angiography, and focused beam therapy. Other applications are x-ray lithography, x-ray astronomy, crystal diffraction, x-ray fluorescence, and neutron prompt gamma analysis.

  19. Spontaneous emission effects in optically pumped x-ray FEL

    Energy Technology Data Exchange (ETDEWEB)

    Smetanin, I.V.; Grigor`ev, S.V. [P.N. Lebedev Physics Institute, Moscow (Russian Federation)

    1995-12-31

    An effect of spontaneous emission in both quantum and classical regimes of the optically pumped X-ray free electron laser (FEL) in investigated. The quantum properties of an FEL are determined by the ratio of the separation {h_bar} between the absorption and emission lines (i.e. the quanta emitted) and their effective width {Delta}{epsilon} {eta}={h_bar}/{Delta}{epsilon}. In the conventional classical regime {eta} {much_lt} 1 an electron emits and absorbes a great number of shortwavelength photons over the interaction region, the gain in FEL being the result of these competitive processes. In the quantum limit {eta} {much_gt} 1 the emission and absorption lines are completely separated and thus the FEL becomes a two-level quantum oscillator with a completely inverted active medium. Spontaneous emission causes the electron to leave the range of energies where resonant interaction with the laser field occurs, thus effectively reducing the number of particles that take part in generating the induced X-ray signal. This effect is found to be crucial for lasing in optically pumped X-ray FEL. The characteristic relaxation times are calculated for both classical and quantum FEL regimes. It is shown that spontaneous emission results in FEL electron beam threshold current, which is of rather high value. An optimal range of pumping laser intensities is determined.

  20. Spatiotemporal response of crystals in x-ray Bragg diffraction

    Science.gov (United States)

    Shvyd'ko, Yuri; Lindberg, Ryan

    2012-10-01

    The spatiotemporal response of crystals in x-ray Bragg diffraction resulting from excitation by an ultrashort, laterally confined x-ray pulse is studied theoretically. The theory presents an extension of the analysis in symmetric reflection geometry [R. R. Lindberg and Y. V. Shvyd’ko, Phys. Rev. ST Accel. Beams 15, 050706 (2012)PRABFM1098-440210.1103/PhysRevSTAB.15.050706] to the generic case, which includes Bragg diffraction both in reflection (Bragg) and transmission (Laue) asymmetric scattering geometries. The spatiotemporal response is presented as a product of a crystal-intrinsic plane-wave spatiotemporal response function and an envelope function defined by the crystal-independent transverse profile of the incident beam and the scattering geometry. The diffracted wave fields exhibit amplitude modulation perpendicular to the propagation direction due to both angular dispersion and the dispersion due to Bragg’s law. The characteristic measure of the spatiotemporal response is expressed in terms of a few parameters: the extinction length, crystal thickness, Bragg angle, asymmetry angle, and the speed of light. Applications to self-seeding of hard x-ray free-electron lasers are discussed, with particular emphasis on the relative advantages of using either the Bragg or Laue scattering geometries. Intensity front inclination in asymmetric diffraction can be used to make snapshots of ultrafast processes with femtosecond resolution.