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Sample records for incident x-ray beam

  1. Characterization of ion beam sputtered deposited W/Si multilayers by grazing incidence x-ray diffraction and x-ray reflectivity technique

    Science.gov (United States)

    Dhawan, Rajnish; Rai, Sanjay

    2016-05-01

    W/Si multilayers four samples have been deposited on silicon substrate using ion beam sputtering system. Thickness of tungsten (W) varies from around 10 Å to 40 Å while the silicon (Si) thickness remains constant at around 30 Å in multilayers [W-Si]x4. The samples have been characterized by grazing incidence X-ray diffraction (GIXRD) and X-ray reflectivity technique (XRR). GIXRD study shows the crystalline behaviour of W/Si multilayer by varying W thickness and it is found that above 20 Å the W film transform from amorphous to crystalline phase and X-ray reflectivity data shows that the roughnesses of W increases on increasing the W thicknesses in W/Si multilayers.

  2. X-ray beam generator

    International Nuclear Information System (INIS)

    Koller, T.J.; Randmer, J.A.

    1977-01-01

    A method of minimizing the preferential angular absorption of the divergent beam from an X-ray generator is described. The generator consists of an X-ray shielded housing with an X-ray transmissive window symmetrically placed in radial alignment with a focal spot area on a sloped target surface of an X-ray tube in the housing. The X-ray tube may be of the stationary anode type or of the rotating anode type. (U.K.)

  3. Improving x-ray fluorescence signal for benchtop polychromatic cone-beam x-ray fluorescence computed tomography by incident x-ray spectrum optimization: a Monte Carlo study.

    Science.gov (United States)

    Manohar, Nivedh; Jones, Bernard L; Cho, Sang Hyun

    2014-10-01

    To develop an accurate and comprehensive Monte Carlo (MC) model of an experimental benchtop polychromatic cone-beam x-ray fluorescence computed tomography (XFCT) setup and apply this MC model to optimize incident x-ray spectrum for improving production/detection of x-ray fluorescence photons from gold nanoparticles (GNPs). A detailed MC model, based on an experimental XFCT system, was created using the Monte Carlo N-Particle (MCNP) transport code. The model was validated by comparing MC results including x-ray fluorescence (XRF) and scatter photon spectra with measured data obtained under identical conditions using 105 kVp cone-beam x-rays filtered by either 1 mm of lead (Pb) or 0.9 mm of tin (Sn). After validation, the model was used to investigate the effects of additional filtration of the incident beam with Pb and Sn. Supplementary incident x-ray spectra, representing heavier filtration (Pb: 2 and 3 mm; Sn: 1, 2, and 3 mm) were computationally generated and used with the model to obtain XRF/scatter spectra. Quasimonochromatic incident x-ray spectra (81, 85, 90, 95, and 100 keV with 10 keV full width at half maximum) were also investigated to determine the ideal energy for distinguishing gold XRF signal from the scatter background. Fluorescence signal-to-dose ratio (FSDR) and fluorescence-normalized scan time (FNST) were used as metrics to assess results. Calculated XRF/scatter spectra for 1-mm Pb and 0.9-mm Sn filters matched (r ≥ 0.996) experimental measurements. Calculated spectra representing additional filtration for both filter materials showed that the spectral hardening improved the FSDR at the expense of requiring a much longer FNST. In general, using Sn instead of Pb, at a given filter thickness, allowed an increase of up to 20% in FSDR, more prominent gold XRF peaks, and up to an order of magnitude decrease in FNST. Simulations using quasimonochromatic spectra suggested that increasing source x-ray energy, in the investigated range of 81-100 ke

  4. Improving x-ray fluorescence signal for benchtop polychromatic cone-beam x-ray fluorescence computed tomography by incident x-ray spectrum optimization: A Monte Carlo study

    Science.gov (United States)

    Manohar, Nivedh; Jones, Bernard L.; Cho, Sang Hyun

    2014-01-01

    Purpose: To develop an accurate and comprehensive Monte Carlo (MC) model of an experimental benchtop polychromatic cone-beam x-ray fluorescence computed tomography (XFCT) setup and apply this MC model to optimize incident x-ray spectrum for improving production/detection of x-ray fluorescence photons from gold nanoparticles (GNPs). Methods: A detailed MC model, based on an experimental XFCT system, was created using the Monte Carlo N-Particle (MCNP) transport code. The model was validated by comparing MC results including x-ray fluorescence (XRF) and scatter photon spectra with measured data obtained under identical conditions using 105 kVp cone-beam x-rays filtered by either 1 mm of lead (Pb) or 0.9 mm of tin (Sn). After validation, the model was used to investigate the effects of additional filtration of the incident beam with Pb and Sn. Supplementary incident x-ray spectra, representing heavier filtration (Pb: 2 and 3 mm; Sn: 1, 2, and 3 mm) were computationally generated and used with the model to obtain XRF/scatter spectra. Quasimonochromatic incident x-ray spectra (81, 85, 90, 95, and 100 keV with 10 keV full width at half maximum) were also investigated to determine the ideal energy for distinguishing gold XRF signal from the scatter background. Fluorescence signal-to-dose ratio (FSDR) and fluorescence-normalized scan time (FNST) were used as metrics to assess results. Results: Calculated XRF/scatter spectra for 1-mm Pb and 0.9-mm Sn filters matched (r ≥ 0.996) experimental measurements. Calculated spectra representing additional filtration for both filter materials showed that the spectral hardening improved the FSDR at the expense of requiring a much longer FNST. In general, using Sn instead of Pb, at a given filter thickness, allowed an increase of up to 20% in FSDR, more prominent gold XRF peaks, and up to an order of magnitude decrease in FNST. Simulations using quasimonochromatic spectra suggested that increasing source x-ray energy, in the

  5. 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.

  6. Diagnosis of secondary caries in esthetic restorations: influence of the incidence vertical angle of the X-ray beam.

    Science.gov (United States)

    Moreira, Patrícia Lima; Messora, Michel Reis; Pereira, Stela Márcia; Almeida, Solange Maria de; Cruz, Adriana Dibo da

    2011-01-01

    The aim of this study was to evaluate the accuracy on the diagnosis of secondary caries-like lesions simulated on esthetic restorations of different materials, changing the incidence vertical angle (IVA) of the x-ray beam. Twenty human teeth received MOD inlay preparations. In the experimental group (n=10), a round cavity was made in the floor of the proximal box to simulate the caries-like lesion. All teeth were restored with 3 composite resins (Charisma, Filtek-Z250 and TPH-Spectrum) at 3 moments. Two radiographic images were acquired with 0º and 10º IVA. Ten observers evaluated the images using a 5-point confidence scale. Intra- and interobserver reliability was analyzed with the Interclass Correlation Coefficient and the diagnostic accuracy was evaluated using the area under the ROC curve (A(z)), Friedman test and Wilcoxon test (α=0.05). Higher accuracy values were obtained with 10º IVA (A(z)=0.66, Filtek-Z250>A(z)=0.56, TPH-Spectrum) compared to 0º (A(z)=0.55, Charisma>A(z)=0.37, TPH-Spectrum), though without statistically significant difference (p>0.05). The detection of secondary caries-like lesions simulated on esthetic restorations of different materials suffered no negative influence by changing the IVA of the x-ray beam.

  7. Electron beam parallel X-ray generator

    Science.gov (United States)

    Payne, P.

    1967-01-01

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

  8. 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...

  9. Molecular-beam epitaxy growth and structural characterization of semiconductor-ferromagnet heterostructures by grazing incidence X-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Satapathy, D.K.

    2005-12-19

    The present work is devoted to the growth of the ferromagnetic metal MnAs on the semiconductor GaAs by molecular-beam epitaxy (MBE). The MnAs thin films are deposited on GaAs by molecular-beam epitaxy (MBE). Grazing incidence diffraction (GID) and reflection high-energy electron diffraction (RHEED) are used in situ to investigate the nucleation, evolution of strain, morphology and interfacial structure during the MBE growth. Four stages of the nucleation process during growth of MnAs on GaAs(001) are revealed by RHEED azimuthal scans. GID shows that further growth of MnAs films proceed via the formation of relaxed islands at a nominal thickness of 2.5 ML which increase in size and finally coalesce to form a continuous film. Early on, an ordered array of misfit dislocations forms at the interface releasing the misfit strain even before complete coalescence occurs. The fascinating complex nucleation process of MnAs on GaAs(0 0 1) contains elements of both Volmer-Weber and Stranski-Krastanov growth. A nonuniform strain amounting to 0.66%, along the [1 -1 0] direction and 0.54%, along the [1 1 0] direction is demonstrated from x-ray line profile analysis. A high correlation between the defects is found along the GaAs[1 1 0] direction. An extremely periodic array of misfit dislocations with a period of 4.95{+-}0.05 nm is formed at the interface along the [1 1 0] direction which releases the 7.5% of misfit. The inhomogeneous strain due to the periodic dislocations is confined at the interface within a layer of 1.6 nm thickness. The misfit along the [1 -1 0] direction is released by the formation of a coincidence site lattice. (orig.)

  10. Automatic Alignment of X-Ray Beams

    International Nuclear Information System (INIS)

    Anderson, Zachary R

    2003-01-01

    Protein crystals and other biological samples diffract weakly in X-rays. It is therefore important that the X-ray beam be very stable. Cubic smoothing splines were fit to ion chamber counts versus the vertical position of the sample. The extrema, inflection points about the maximum, and other information about the spline were calculated to determine whether the data corresponded to a beam profile. The algorithm developed here correctly identified the absence of a beam profile in all data gathered over the course of a year from four beam lines at the Stanford Synchrotron Radiation Laboratory. This algorithm is effective and can be adapted to other beam lines

  11. Micromirror-based manipulation of synchrotron x-ray beams

    Science.gov (United States)

    Walko, D. A.; Chen, Pice; Jung, I. W.; Lopez, D.; Schwartz, C. P.; Shenoy, G. K.; Wang, Jin

    2017-08-01

    Synchrotron beamlines typically use macroscopic, quasi-static optics to manipulate x-ray beams. We present the use of dynamic microelectromechanical systems-based optics (MEMS) to temporally modulate synchrotron x-ray beams. We demonstrate this concept using single-crystal torsional MEMS micromirrors oscillating at frequencies of 75 kHz. Such a MEMS micromirror, with lateral dimensions of a few hundred micrometers, can interact with x rays by operating in grazing-incidence reflection geometry; x rays are deflected only when an x-ray pulse is incident on the rotating micromirror under appropriate conditions, i.e., at an angle less than the critical angle for reflectivity. The time window for such deflections depends on the frequency and amplitude of the MEMS rotation. We demonstrate that reflection geometry can produce a time window of a few microseconds. We further demonstrate that MEMS optics can isolate x rays from a selected synchrotron bunch or group of bunches. With ray-trace simulations we explain the currently achievable time windows and suggest a path toward improvements.

  12. Apparatus for monitoring X-ray beam alignment

    Science.gov (United States)

    Steinmeyer, P.A.

    1991-10-08

    A self-contained, hand-held apparatus is provided for monitoring alignment of an X-ray beam in an instrument employing an X-ray source. The apparatus includes a transducer assembly containing a photoresistor for providing a range of electrical signals responsive to a range of X-ray beam intensities from the X-ray beam being aligned. A circuit, powered by a 7.5 VDC power supply and containing an audio frequency pulse generator whose frequency varies with the resistance of the photoresistor, is provided for generating a range of audible sounds. A portion of the audible range corresponds to low X-ray beam intensity. Another portion of the audible range corresponds to high X-ray beam intensity. The transducer assembly may include an a photoresistor, a thin layer of X-ray fluorescent material, and a filter layer transparent to X-rays but opaque to visible light. X-rays from the beam undergoing alignment penetrate the filter layer and excite the layer of fluorescent material. The light emitted from the fluorescent material alters the resistance of the photoresistor which is in the electrical circuit including the audio pulse generator and a speaker. In employing the apparatus, the X-ray beam is aligned to a complete alignment by adjusting the X-ray beam to produce an audible sound of the maximum frequency. 2 figures.

  13. Effective energies and exposure determinations of two different energy X-ray beams incident on a personnel monitor

    International Nuclear Information System (INIS)

    Okuno, E.; Cruz, M.T. da

    1984-01-01

    The effective energy of one X or gamma ray beam can be determined by means of two thermoluminescent (TL) dosemeters mounted between suitable filters. However, it has been observed that personnel monitors exposed to two different energy ionizing radiations provide different effective energies depeding on the type of TL phosphor used. This fact could be a powerful tool for identifying exposures to radiation with quite different effective energies which are very common in practice. Two types of TL dosemeters were used : pellets of cold pressed natural fluoride and NaCl developed in our own laboratory, and LiF, TLD-100 from Harshaw Chemical Co.. Experimental results obtained with these combined dosemeters after irradiation with different sets of exposures and energy values of ionizing radiations are also presented. (Author) [pt

  14. Adjustable Grazing-Incidence X-Ray Optics

    Science.gov (United States)

    O'Dell, Stephen L.; Reid, Paul B.

    2015-01-01

    With its unique subarcsecond imaging performance, NASA's Chandra X-ray Observatory illustrates the importance of fine angular resolution for x-ray astronomy. Indeed, the future of x-ray astronomy relies upon x-ray telescopes with comparable angular resolution but larger aperture areas. Combined with the special requirements of nested grazing-incidence optics, mass, and envelope constraints of space-borne telescopes render such advances technologically and programmatically challenging. The goal of this technology research is to enable the cost-effective fabrication of large-area, lightweight grazing-incidence x-ray optics with subarcsecond resolution. Toward this end, the project is developing active x-ray optics using slumped-glass mirrors with thin-film piezoelectric arrays for correction of intrinsic or mount-induced distortions.

  15. Uniformity of the soft-x-ray emissions from gold foils irradiated by OMEGA laser beams determined by a two-mirror normal-incidence microscope with multilayer coatings

    International Nuclear Information System (INIS)

    Seely, John F.; Boehly, Thomas; Pien, Gregory; Bradley, David

    1998-01-01

    A two-mirror normal-incidence microscope with multilayer coatings was used to image the soft-x-ray emissions from planar foils irradiated by OMEGA laser beams. The bandpass of the multilayer coatings was centered at a wavelength of 48.3 Angstrom (257-eV energy) and was 0.5 Angstrom wide. Five overlapping OMEGA beams, without beam smoothing, were typically incident on the gold foils. The total energy was 1500 J, and the focused intensity was 6x10 13 Wcm -2 . The 5.8x magnified images were recorded by a gated framing camera at various times during the 3-ns laser pulse. A pinhole camera imaged the x-ray emission in the energy range of >2 keV. On a spatial scale of 10 μm, it was found that the soft-x-ray images at 257 eV were quite uniform and featureless. In contrast, the hard-x-ray images in the energy range of >2 kev were highly nonuniform with numerous features of size 150 μm. copyright 1998 Optical Society of America

  16. Grazing Incidence X-ray Scattering and Diffraction

    Indian Academy of Sciences (India)

    IAS Admin

    tion. In thia article, various aspects of surface X- ray diffraction and scattering are discussed with illustrations of some typical applications of these techniques. 1. ..... ray reflectivity. Here, X-rays are incident on the sample at very small grazing angles to the surface and below the critical angle, αc. As explained earlier, this ...

  17. Scattered X-ray beam nondestructive testing

    International Nuclear Information System (INIS)

    Harding, G.; Kosanetzky, J.

    1988-01-01

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

  18. The Marshall Grazing Incidence X-ray Spectrometer

    Science.gov (United States)

    Kobayashi, Ken; Winebarger, Amy R.; Savage, Sabrina; Champey, Patrick; Cheimets, Peter N.; Hertz, Edward; Bruccoleri, Alexander R.; Golub, Leon; Ramsey, Brian; Ranganathan, Jaganathan; Marquez, Vanessa; Allured, Ryan; Parker, Theodore; Heilmann, Ralf K.; Schattenburg, Mark L.

    2017-08-01

    The Marshall Grazing Incidence X-ray Spectrometer (MaGIXS) is a NASA sounding rocket instrument designed to obtain spatially resolved soft X-ray spectra of the solar atmosphere in the 6-24 Å (0.5-2.0 keV) range. The instrument consists of a single shell Wolter Type-I telescope, a slit, and a spectrometer comprising a matched pair of grazing incidence parabolic mirrors and a planar varied-line space diffraction grating. The instrument is designed to achieve a 50 mÅ spectral resolution and 5 arcsecond spatial resolution along a +/-4-arcminute long slit, and launch is planned for 2019. We report on the status and our approaches for fabrication and alignment for this novel optical system. The telescope and spectrometer mirrors are replicated nickel shells, and are currently being fabricated at the NASA Marshall Space Flight Center. The diffraction grating is currently under development by the Massachusetts Institute of Technology (MIT); because of the strong line spacing variation across the grating, it will be fabricated through e-beam lithography.

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

    International Nuclear Information System (INIS)

    Chen, Dongmei; Zhu, Shouping; Chen, Xueli; Chao, Tiantian; Cao, Xu; Zhao, Fengjun; Huang, Liyu; Liang, Jimin

    2014-01-01

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

  20. X-ray pencil beam facility for optics characterization

    Science.gov (United States)

    Krumrey, Michael; Cibik, Levent; Müller, Peter; Bavdaz, Marcos; Wille, Eric; Ackermann, Marcelo; Collon, Maximilien J.

    2010-07-01

    The Physikalisch-Technische Bundesanstalt (PTB) has used synchrotron radiation for the characterization of optics and detectors for astrophysical X-ray telescopes for more than 20 years. At a dedicated beamline at BESSY II, a monochromatic pencil beam is used by ESA and cosine Research since the end of 2005 for the characterization of novel silicon pore optics, currently under development for the International X-ray Observatory (IXO). At this beamline, a photon energy of 2.8 keV is selected by a Si channel-cut monochromator. Two apertures at distances of 12.2 m and 30.5 m from the dipole source form a pencil beam with a typical diameter of 100 μm and a divergence below 1". The optics to be investigated is placed in a vacuum chamber on a hexapod, the angular positioning is controlled by means of autocollimators to below 1". The reflected beam is registered at 5 m distance from the optics with a CCD-based camera system. This contribution presents design and performance of the upgrade of this beamline to cope with the updated design for IXO. The distance between optics and detector can now be 20 m. For double reflection from an X-ray Optical Unit (XOU) and incidence angles up to 1.4°, this corresponds to a vertical translation of the camera by 2 m. To achieve high reflectance at this angle even with uncoated silicon, a lower photon energy of 1 keV is available from a pair of W/B4C multilayers. For coated optics, a high energy option can provide a pencil beam of 7.6 keV radiation.

  1. Design and development of grazing incidence x-ray mirrors

    Science.gov (United States)

    Zuo, Fuchang; Mei, Zhiwu; Ma, Tao; Deng, Loulou; Shi, Yongqiang; Li, Liansheng

    2016-01-01

    X-ray pulsar navigation has attracted extensive attentions from academy and engineering domains. The navigation accuracy is can be enhanced through design of X-ray mirrors to focus X-rays to a small detector. The Wolter-I optics, originally proposed based on a paraboloid mirror and a hyperboloid mirror for X-ray imaging, has long been widely developed and employed in X-ray observatory. Some differences, however, remain in the requirements on optics between astronomical X-ray observation and pulsar navigation. The simplified Wolter-I optics, providing single reflection by a paraboloid mirror, is more suitable for pulsar navigation. In this paper, therefore, the grazing incidence X-ray mirror was designed further based on our previous work, with focus on the reflectivity, effective area, angular resolution and baffles. To evaluate the performance of the manufactured mirror, the surface roughness and reflectivity were tested. The test results show that the grazing incidence mirror meets the design specifications. On the basis of this, the reflectivity of the mirror in the working bandwidth was extrapolated to evaluate the focusing ability of the mirror when it works together with the detector. The purpose of our current work to design and develop a prototype mirror was realized. It can lay a foundation and provide guidance for the development of multilayer nested X-ray mirror with larger effective area.

  2. A beam expander facility for studying x-ray optics

    DEFF Research Database (Denmark)

    Christensen, Finn Erland; Hornstrup, Allan; Frederiksen, P.

    1992-01-01

    The detailed study of the performance of full scale x-ray optics often requires the illumination of large areas. This paper describes a beam expander facility at the Daresbury Synchrotron Radiation Facility. It combines monochromatization and beam expansion in one dimension. The beam expansion...... x-ray telescope will be studied, is described in detail. Review of Scientific Instruments is copyrighted by The American Institute of Physics....

  3. Cone-beam x-ray luminescence computed tomography based on x-ray absorption dosage

    Science.gov (United States)

    Liu, Tianshuai; Rong, Junyan; Gao, Peng; Zhang, Wenli; Liu, Wenlei; Zhang, Yuanke; Lu, Hongbing

    2018-02-01

    With the advances of x-ray excitable nanophosphors, x-ray luminescence computed tomography (XLCT) has become a promising hybrid imaging modality. In particular, a cone-beam XLCT (CB-XLCT) system has demonstrated its potential in in vivo imaging with the advantage of fast imaging speed over other XLCT systems. Currently, the imaging models of most XLCT systems assume that nanophosphors emit light based on the intensity distribution of x-ray within the object, not completely reflecting the nature of the x-ray excitation process. To improve the imaging quality of CB-XLCT, an imaging model that adopts an excitation model of nanophosphors based on x-ray absorption dosage is proposed in this study. To solve the ill-posed inverse problem, a reconstruction algorithm that combines the adaptive Tikhonov regularization method with the imaging model is implemented for CB-XLCT reconstruction. Numerical simulations and phantom experiments indicate that compared with the traditional forward model based on x-ray intensity, the proposed dose-based model could improve the image quality of CB-XLCT significantly in terms of target shape, localization accuracy, and image contrast. In addition, the proposed model behaves better in distinguishing closer targets, demonstrating its advantage in improving spatial resolution.

  4. X-ray zone plates fabricated using electron-beam and x-ray lithography

    International Nuclear Information System (INIS)

    Shaver, D.C.; Flanders, D.C.; Ceglio, N.M.; Smith, H.I.

    1979-01-01

    Fresnel zone plate patterns, free of spherical abberation, with diameters of up to 0.63 mm and linewidths as small as 1000 A were fabricated on polyimide-membrane x-ray masks using scanning electron beam lithography Distortion of the electron beam scan raster was reduced to < 2500 A over a 2 mm x 2 mm field by applying deflection corrections, while viewing the distortion using a moire method. C/sub k/ x-ray lithography was used to replicate the zone plate pattern in thick PMMA over a 100 A thick plating base on a glass substrate. Zones plates in 1.3 μm thick gold were fabricated by plating, and made free-standing by removal of the plating base and the supporting glass substrate. Zone plates were tested as imaging elements with visible light and soft x-rays

  5. X-ray zone plates fabricated using electron-beam and x-ray lithography

    Energy Technology Data Exchange (ETDEWEB)

    Shaver, D.C.; Flanders, D.C.; Ceglio, N.M.; Smith, H.I.

    1979-01-01

    Fresnel zone plate patterns, free of spherical abberation, with diameters of up to 0.63 mm and linewidths as small as 1000 A were fabricated on polyimide-membrane x-ray masks using scanning electron beam lithography Distortion of the electron beam scan raster was reduced to < 2500 A over a 2 mm x 2 mm field by applying deflection corrections, while viewing the distortion using a moire method. C/sub k/ x-ray lithography was used to replicate the zone plate pattern in thick PMMA over a 100 A thick plating base on a glass substrate. Zones plates in 1.3 ..mu..m thick gold were fabricated by plating, and made free-standing by removal of the plating base and the supporting glass substrate. Zone plates were tested as imaging elements with visible light and soft x-rays.

  6. Development of a multi-lane X-ray mirror providing variable beam sizes

    Energy Technology Data Exchange (ETDEWEB)

    Laundy, D., E-mail: david.laundy@diamond.ac.uk; Sawhney, K.; Nistea, I.; Alcock, S. G.; Pape, I.; Sutter, J.; Alianelli, L.; Evans, G. [Diamond Light Source Ltd., Harwell Science and Innovation Campus, Didcot OX11 0DE (United Kingdom)

    2016-05-15

    Grazing incidence mirrors are used on most X-ray synchrotron beamlines to focus, collimate or suppress harmonics. Increasingly beamline users are demanding variable beam shapes and sizes at the sample position. We have now developed a new concept to rapidly vary the beam size and shape of a focused X-ray beam. The surface of an elliptically figured mirror is divided into a number of laterally separated lanes, each of which is given an additional longitudinal height profile calculated to shape the X-ray beam to a top-hat profile in the focal plane. We have now fabricated two prototype mirrors and present the results of metrology tests and measurements made with one of the mirrors focusing the X-rays on a synchrotron beamline. We envisage that such mirrors could be widely applied to rapid beam-size switching on many synchrotron beamlines.

  7. Nanoparticle-Assisted Scanning Focusing X-Ray Therapy with Needle Beam X Rays.

    Science.gov (United States)

    Davidson, R Andrew; Guo, Ting

    2016-01-01

    In this work, we show a new therapeutic approach using 40-120 keV X rays to deliver a radiation dose at the isocenter located many centimeters below the skin surface several hundred times greater than at the skin and how this dose enhancement can be augmented with nanomaterials to create several thousand-fold total dose enhancement effect. This novel approach employs a needle X-ray beam directed at the isocenter centimeters deep in the body while continuously scanning the beam to cover a large solid angle without overlapping at the skin. A Monte Carlo method was developed to simulate an X-ray dose delivered to the isocenter filled with X-ray absorbing and catalytic nanoparticles in a water phantom. An experimental apparatus consisting of a moving plastic phantom irradiated with a stationary 1 mm needle X-ray beam was built to test the theoretical predictions. X-ray films were used to characterize the dose profiles of the scanning X-ray apparatus. Through this work, it was determined that the X-ray dose delivered to the isocenter in a treatment voxel (t-voxel) underneath a 5 cm deep high-density polyethylene (HDPE) phantom was 295 ± 48 times greater than the surface dose. This measured value was in good agreement with the theoretical predicted value of 339-fold. Adding X-ray-absorbing nanoparticles, catalytic nanoparticles or both into the t-voxel can further augment the dose enhancement. For example, we predicted that adding 1 weight percentage (wp) of gold into water could increase the effective dose delivered to the target by onefold. Dose enhancement using 1 mm X-ray beam could reach about 1,600-fold in the t-voxel when 7.5 wp of 88 nm diameter silica-covered gold nanoparticles were added, which we showed in a previously published study can create a dose enhancement of 5.5 ± 0.46-fold without scanning focusing enhancement. Based on the experimental data from that study, mixing 0.02 wp 2.5 nm diameter small tetrakis hydroxymethyl phosphonium chloride (THPC

  8. An x-ray technique for precision laser beam synchronization

    International Nuclear Information System (INIS)

    Landen, O.L.; Lerche, R.A.; Hay, R.G.; Hammel, B.A.; Kalantar, D.; Cable, M.D.

    1994-01-01

    A new x-ray technique for recording the relative arrival times of multiple laser beams at a common target with better than ± 10 ps accuracy has been implemented at the Nova laser facility. 100 ps, 3ω Nova beam are focused to separate locations on a gold ribbon target viewed from the side. The measurement consists of using well characterized re-entrant x-ray streak cameras for 1-dimensional streaked imaging of the > 3 keV x-rays emanating from these isolated laser plasmas. After making the necessary correction for the differential laser, x-ray and electron transit times involved, timing offsets as low as ± 7 ps are resolved, and on subsequent shots, corrected for, verified and independently checked. This level of synchronization proved critical in meeting the power balance requirements for indirectly-driven pulse-shaped Nova implosions

  9. A new beamstop for microfocus X-ray capillary beams

    International Nuclear Information System (INIS)

    Englich, Ulrich; Revesz, Peter; Miller, William

    2011-01-01

    In order to accurately measure the photon flux and to assist in aligning the beam, we have designed a modified beamstop device based on a photo diode integrated with the beamstop. The beamstop contains a small CdWO 4 crystal that completely stops the X-rays and at the same time produces photoluminescence proportional to the X-ray flux. The light is then guided to a photosensitive diode using a flexible light pipe to monitor the flux. With this device we achieve the goal of stopping the primary X-ray beam and simultaneously monitoring the X-ray intensity, thus eliminating the need for integrating ion-chambers into the capillary or collimator mount.

  10. Advances in kilovoltage x-ray beam dosimetry

    Science.gov (United States)

    Hill, Robin; Healy, Brendan; Holloway, Lois; Kuncic, Zdenka; Thwaites, David; Baldock, Clive

    2014-03-01

    This topical review provides an up-to-date overview of the theoretical and practical aspects of therapeutic kilovoltage x-ray beam dosimetry. Kilovoltage x-ray beams have the property that the maximum dose occurs very close to the surface and thus, they are predominantly used in the treatment of skin cancers but also have applications for the treatment of other cancers. In addition, kilovoltage x-ray beams are used in intra operative units, within animal irradiators and in on-board imagers on linear accelerators and kilovoltage dosimetry is important in these applications as well. This review covers both reference and relative dosimetry of kilovoltage x-ray beams and provides recommendations for clinical measurements based on the literature to date. In particular, practical aspects for the selection of dosimeter and phantom material are reviewed to provide suitable advice for medical physicists. An overview is also presented of dosimeters other than ionization chambers which can be used for both relative and in vivo dosimetry. Finally, issues related to the treatment planning and the use of Monte Carlo codes for solving radiation transport problems in kilovoltage x-ray beams are presented.

  11. Effect of toroidal mirror on spatial coherence of synchrotron hard X-ray beams

    International Nuclear Information System (INIS)

    Wang Hua; Yan Shuai; Yan Fen; Mao Chengwen; Liang Dongxun; He Yan; Jiang Sheng; Li Aiguo; Yu Xiaohan

    2012-01-01

    The Gaussian Schell-model source theory is used to describe the hard X-ray micro focusing beamline with an undulator of the Shanghai Synchrotron Radiation Facility. Based on the model and general Huygens-Fresnel principle, propagation of cross-spectral density function in free space is studied. Equivalent source hypothesis is proposed and the effect of toroidal mirror on spatial coherence of the hard X-ray beams is studied. The theoretical results are consistent with the experimental results. Only divergence angles of the incident and outgoing X-rays are considered in the equivalent source hypothesis, hence an easy extension of the hypothesis to other beamline optical elements. (authors)

  12. Beam conditioning multilayer optics for laboratory x-ray sources

    Science.gov (United States)

    Platonov, Yuriy; Verman, Boris; Jiang, Licai; Kim, Bonglea

    2015-08-01

    Practically, all modern x-ray diffractometers, SAXS, TXRF systems and many other laboratory X-ray instruments are equipped with multilayer X-ray optics. It is due to a much higher flux these instruments have comparing with those having no optics or having a grazing incidence optics without multilayer coatings. There are variety of the multilayer optics designs - from one bounce collimating parabolic mirror to four corners double bounce focusing mirrors. Design of multilayer optics depends on application, X-ray source parameters, requirements on divergence, focal spot, available room for the optics, manufacturing capability and cost. Key characteristics of the optics, requirements on multilayers d-spacing accuracy, optics slope errors, and substrates surface roughness are discussed in the paper. Different optics designs are considered including recently developed optics for a laboratory topography system and a Hybrid optics combining multilayer and crystal optics for XRR and XRD.

  13. X-ray beam method for displacement measurement in hostile environments

    Science.gov (United States)

    Jordan, Eric H.; Pease, D. M.; Canistraro, H.; Brew, Dale

    1989-01-01

    A new method of extensometry using an X-ray beam was devised, and the results of current testing reveal it to be highly feasible. This technique has been shown to provide a non-contacting system that is immune to problems associated with density variations in gaseous environments, that plague currently available optical methods. This advantage is a result of the non-refracting penetrating nature of X-rays. The method is based on X-ray-induced X-ray fluorescence of targets, which subsequently serve as fudicial markers. Some target materials have melting points over 1600 degrees C which will facilitate measurement at extremely high temperatures. A highly focused intense X-ray beam, which is produced using a Johansen 'bent crystal', is then scanned across the target, which responds by fluorescing X-rays when stimulated by the incident beam. This secondary radiation is monitored using a detector. By carefully measuring beam orientation, change in target edge position can be determined. Many variations on this basic theme are now possible such as two targets demarcating a gage length, or a beam shadowing method using opaque targets.

  14. X-ray trace element analysis with positive ion beams

    International Nuclear Information System (INIS)

    Davis, R.H.

    1973-01-01

    A new trace element analysis having the advantage that many elements may be detected in a single measurement, based on positive charged particle induced X-ray florescence and on the production of X-rays by heavy ions, is described. Because of the large cross-sections for the production of discrete X-ray and the low yield of continuum radiation, positive charged particle X-ray florescence is a competitive, fast, analytic tool. In the experiment a beam of positive charged particles from an accelerator was directed toward a target. X-rays induced by the bombardment were detected by a Si(Li) detector the ouput from which was amplified and sorted in a multichannel analyzer. For rapid data handling and analysis, the multichannel analyzer or ADC unit was connected to an on-line computer. A large variety of targets prepared in collaboration with the oceanographers have been studied and spectra obtained for different particles having the same velocity are presented to show that the yield of discrete X-rays increases at least as rapidly as Z 2 . While protons of several MeV appear to be already competitive further advantage may be gained by heavy ions at lower energies since the continuum is reduced while the peak ''signals'' retain strength due to the Z 2 dependence. (S.B.)

  15. Highly porous nanoberyllium for X-ray beam speckle suppression

    Energy Technology Data Exchange (ETDEWEB)

    Goikhman, Alexander, E-mail: agoikhman@ymail.com; Lyatun, Ivan; Ershov, Petr [Immanuel Kant Baltic Federal University, Nevskogo str. 14, Kaliningrad 236041 (Russian Federation); Snigireva, Irina [European Synchrotron Radiation Facility, BP 220, 38043 Grenoble (France); Wojda, Pawel [Immanuel Kant Baltic Federal University, Nevskogo str. 14, Kaliningrad 236041 (Russian Federation); Gdańsk University of Technology, 11/12 G. Narutowicza, Gdańsk 80-233 (Poland); Gorlevsky, Vladimir; Semenov, Alexander; Sheverdyaev, Maksim; Koletskiy, Viktor [A. A. Bochvar High-Technology Scientific Research Institute for Inorganic Materials, Rogova str. 5a, Moscow 123098 (Russian Federation); Snigirev, Anatoly [Immanuel Kant Baltic Federal University, Nevskogo str. 14, Kaliningrad 236041 (Russian Federation); European Synchrotron Radiation Facility, BP 220, 38043 Grenoble (France)

    2015-04-09

    A speckle suppression device containing highly porous nanoberyllium is proposed for manipulating the spatial coherence length and removing undesirable speckle structure during imaging experiments. This paper reports a special device called a ‘speckle suppressor’, which contains a highly porous nanoberyllium plate squeezed between two beryllium windows. The insertion of the speckle suppressor in an X-ray beam allows manipulation of the spatial coherence length, thus changing the effective source size and removing the undesirable speckle structure in X-ray imaging experiments almost without beam attenuation. The absorption of the nanoberyllium plate is below 1% for 1 mm thickness at 12 keV. The speckle suppressor was tested on the ID06 ESRF beamline with X-rays in the energy range from 9 to 15 keV. It was applied for the transformation of the phase–amplitude contrast to the pure amplitude contrast in full-field microscopy.

  16. Highly porous nanoberyllium for X-ray beam speckle suppression

    International Nuclear Information System (INIS)

    Goikhman, Alexander; Lyatun, Ivan; Ershov, Petr; Snigireva, Irina; Wojda, Pawel; Gorlevsky, Vladimir; Semenov, Alexander; Sheverdyaev, Maksim; Koletskiy, Viktor; Snigirev, Anatoly

    2015-01-01

    A speckle suppression device containing highly porous nanoberyllium is proposed for manipulating the spatial coherence length and removing undesirable speckle structure during imaging experiments. This paper reports a special device called a ‘speckle suppressor’, which contains a highly porous nanoberyllium plate squeezed between two beryllium windows. The insertion of the speckle suppressor in an X-ray beam allows manipulation of the spatial coherence length, thus changing the effective source size and removing the undesirable speckle structure in X-ray imaging experiments almost without beam attenuation. The absorption of the nanoberyllium plate is below 1% for 1 mm thickness at 12 keV. The speckle suppressor was tested on the ID06 ESRF beamline with X-rays in the energy range from 9 to 15 keV. It was applied for the transformation of the phase–amplitude contrast to the pure amplitude contrast in full-field microscopy

  17. Phototransistor: a detector for x-ray beam dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Luiz Antonio P. dos [Centro Regional de Ciencias Nucleares (CRCN), Recife, PE (Brazil); Silva Junior, Eronides F. da [Pernambuco Univ., Recife, PE (Brazil). Dept. de Fisica; Hazin, Clovis A.; Santos, Walter [Pernambuco Univ., Recife, PE (Brazil). Dept. de Energia Nuclear

    2002-07-01

    We evaluate the feasibility of the diagnostic X-ray beam dose be estimated using phototransistor-type semiconductor devices. In this radiation range, its detection performance has been compared to that of photodiodes and ionization chambers. X-ray diagnostic results with different phototransistors indicate that they present the best detector responses for monitoring, in real-time, the entrance dose and estimating the absorbed dose at the small-size tissue region in human body. Additionally, the phototransistors can also be used for monitoring the radiosurgery planing quality. (author)

  18. Soft X-ray beam induced current technique

    Energy Technology Data Exchange (ETDEWEB)

    Watts, B; Ade, H [Department of Physics, North Carolina State University, Raleigh, NC 27695 (United States); Queen, D; Hellman, F [Department of Physics, University of California, Berkeley, CA 94720 (United States); Kilcoyne, A L D; Tyliszczak, T, E-mail: benjamin.watts@gmail.co [Advanced Light Source, Lawrence Berkeley Nat. Lab., Berkeley, CA 94720 (United States)

    2009-09-01

    Direct mapping of the charge transport efficiency of polymer solar cell devices using a soft X-ray beam induced current (SoXBIC) method is described. By fabricating a polymer solar cell on an x-ray transparent substrate, we demonstrate the ability to map polymer composition and nanoscale structure within an operating solar cell device and to simultaneously measure the local charge transport efficiency via the short-circuit current. A simple model is calculated and compared to experimental SoXBIC data of a PFB:F8BT bulk-heterojunction device in order to gain greater insight into the device operation and physics.

  19. An X-ray grazing incidence phase multilayer grating

    CERN Document Server

    Chernov, V A; Mytnichenko, S V

    2001-01-01

    An X-ray grazing incidence phase multilayer grating, representing a thin grating placed on a multilayer mirror, is proposed. A high efficiency of grating diffraction can be obtained by the possibility of changing the phase shift of the wave diffracted from the multilayer under the Bragg and total external reflection conditions. A grazing incidence phase multilayer grating consisting of Pt grating stripes on a Ni/C multilayer and optimized for the hard X-ray range was fabricated. Its diffraction properties were studied at photon energies of 7 and 8 keV. The obtained maximum value of the diffraction efficiency of the +1 grating order was 9% at 7 keV and 6.5% at 8 keV. The data obtained are in a rather good accordance with the theory.

  20. Editorial: Focus on X-ray Beams with High Coherence

    Science.gov (United States)

    Robinson, Ian; Gruebel, Gerhard; Mochrie, Simon

    2010-03-01

    This editorial serves as the preface to a special issue of New Journal of Physics, which collects together solicited papers on a common subject, x-ray beams with high coherence. We summarize the issue's content, and explain why there is so much current interest both in the sources themselves and in the applications to the study of the structure of matter and its fluctuations (both spontaneous and driven). As this collection demonstrates, the field brings together accelerator physics in the design of new sources, particle physics in the design of detectors, and chemical and materials scientists who make use of the coherent beams produced. Focus on X-ray Beams with High Coherence Contents Femtosecond pulse x-ray imaging with a large field of view B Pfau, C M Günther, S Schaffert, R Mitzner, B Siemer, S Roling, H Zacharias, O Kutz, I Rudolph, R Treusch and S Eisebitt The FERMI@Elettra free-electron-laser source for coherent x-ray physics: photon properties, beam transport system and applications E Allaria, C Callegari, D Cocco, W M Fawley, M Kiskinova, C Masciovecchio and F Parmigiani Beyond simple exponential correlation functions and equilibrium dynamics in x-ray photon correlation spectroscopy Anders Madsen, Robert L Leheny, Hongyu Guo, Michael Sprung and Orsolya Czakkel The Coherent X-ray Imaging (CXI) instrument at the Linac Coherent Light Source (LCLS) Sébastien Boutet and Garth J Williams Dynamics and rheology under continuous shear flow studied by x-ray photon correlation spectroscopy Andrei Fluerasu, Pawel Kwasniewski, Chiara Caronna, Fanny Destremaut, Jean-Baptiste Salmon and Anders Madsen Exploration of crystal strains using coherent x-ray diffraction Wonsuk Cha, Sanghoon Song, Nak Cheon Jeong, Ross Harder, Kyung Byung Yoon, Ian K Robinson and Hyunjung Kim Coherence properties of the European XFEL G Geloni, E Saldin, L Samoylova, E Schneidmiller, H Sinn, Th Tschentscher and M Yurkov Fresnel coherent diffractive imaging: treatment and analysis of data G J

  1. Beam dynamics simulation in the X-ray Compton source

    Energy Technology Data Exchange (ETDEWEB)

    Gladkikh, P.; Karnaukhov, I.; Telegin, Yu.; Shcherbakov, A. E-mail: shcherbakov@kipt.kharkov.ua; Zelinsky, A

    2002-05-01

    At the National Science Center 'Kharkov Institute of Physics and Technology' the X-ray source based on Compton scattering has been developed. The computer code for simulation of electron beam dynamics with taking into account the Compton scattering effect based on Monte Carlo method is described in this report. The first results of computer simulation of beam dynamics with electron-photon interaction, parameters of electron and photon beams are presented. Calculations were carried out with the lattice of synchrotron light source SRS-800 Ukrainian Synchrotron Center.

  2. Beam dynamics simulation in the X-ray Compton source

    International Nuclear Information System (INIS)

    Gladkikh, P.; Karnaukhov, I.; Telegin, Yu.; Shcherbakov, A.; Zelinsky, A.

    2002-01-01

    At the National Science Center 'Kharkov Institute of Physics and Technology' the X-ray source based on Compton scattering has been developed. The computer code for simulation of electron beam dynamics with taking into account the Compton scattering effect based on Monte Carlo method is described in this report. The first results of computer simulation of beam dynamics with electron-photon interaction, parameters of electron and photon beams are presented. Calculations were carried out with the lattice of synchrotron light source SRS-800 Ukrainian Synchrotron Center

  3. Beam dynamics simulation in the X-ray Compton source

    CERN Document Server

    Gladkikh, P; Telegin, Yu P; Shcherbakov, A; Zelinsky, A

    2002-01-01

    At the National Science Center 'Kharkov Institute of Physics and Technology' the X-ray source based on Compton scattering has been developed. The computer code for simulation of electron beam dynamics with taking into account the Compton scattering effect based on Monte Carlo method is described in this report. The first results of computer simulation of beam dynamics with electron-photon interaction, parameters of electron and photon beams are presented. Calculations were carried out with the lattice of synchrotron light source SRS-800 Ukrainian Synchrotron Center.

  4. Sagittal x-ray beam deviation at asymmetric inclined diffractors

    Czech Academy of Sciences Publication Activity Database

    Korytár, D.; Hrdý, Jaromír; Artemiev, Nikolai; Ferrari, C.; Freund, A.

    2001-01-01

    Roč. 8, - (2001), s. 1136-1139 ISSN 0909-0495 R&D Projects: GA MŠk OK 305; GA MPO PZ-CH/22 Institutional research plan: CEZ:AV0Z1010914 Keywords : x-ray optics * Si(111) W/grooved crystals * inclined diffraction * out-of-diffraction-plane beams * sagittal focusing Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.519, year: 2001

  5. Scintillator materials for x-ray detectors and beam monitors

    Czech Academy of Sciences Publication Activity Database

    Martin, T.; Koch, A.; Nikl, Martin

    2017-01-01

    Roč. 42, č. 6 (2017), s. 451-456 ISSN 0883-7694 R&D Projects: GA ČR GA16-15569S Institutional support: RVO:68378271 Keywords : scintillator * X-ray detector * beam monitor * synchrotron * thin film Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 5.199, year: 2016

  6. X-ray diffraction and imaging with a coherent beam: application to X-ray optical elements and to crystals exhibiting phase inhomogeneities

    International Nuclear Information System (INIS)

    Masiello, F.

    2011-05-01

    The exceptional properties of synchrotron light sources have been exploited in very different disciplines, from archaeology to chemistry, from material science to biology, from medicine to physics. Among these properties it is important to mention the high brilliance, continuum spectrum, high degree of polarization, time structure, small source size and divergence of the beam, the last resulting in a high transversal coherence of the produced radiation. This high transversal coherence of the synchrotron sources has permitted the development of new techniques, e.g. phase contrast imaging, X-ray photon correlation spectroscopy and coherent X-ray diffraction imaging (CXDI). This thesis work will consist essentially of three parts. In the first part it will be presented the work done as a member of the X-ray Optics Group of ESRF in the characterization of high quality diamond crystals foreseen as X-ray optical elements. The characterization has been done using different complementary X-ray techniques, such as high resolution diffraction, topography, grazing incidence diffraction, reflectivity and measurements of the coherence preservation using the Talbot effect. In the second part, I will show the result obtained in the study of the temperature behaviours of the domain in periodically poled ferroelectrics crystals. This type of measurements, based on Bragg-Fresnel diffraction, are possible only thanks to the high degree of coherence of the beam. In the third part, I will present the results obtained in the characterization of diamonds foreseen for applications other than X-ray optical elements. (author)

  7. Modern approaches to investigation of thin films and monolayers: X-ray reflectivity, grazing-incidence X-ray scattering and X-ray standing waves

    Science.gov (United States)

    Shcherbina, M. A.; Chvalun, S. N.; Ponomarenko, S. A.; Kovalchuk, M. V.

    2014-12-01

    The review concerns modern experimental methods of structure determination of thin films of different nature. The methods are based on total reflection of X-rays from the surface and include X-ray reflectivity, grazing-incidence X-ray scattering and X-ray standing waves. Their potential is exemplified by the investigations of various organic macromolecular systems that exhibit the properties of semiconductors and are thought to be promising as thin-film transistors, light-emitting diodes and photovoltaic cells. It is shown that combination of the title methods enable high-precision investigations of the structure of thin-film materials and structure formation in them, i.e., it is possible to obtain information necessary for improvement of the operating efficiency of elements of organic electronic devices. The bibliography includes 92 references.

  8. Adjustable hollow-cone output x-ray beam from an ellipsoidal monocapillary with a pinhole and a beam stop.

    Science.gov (United States)

    Sun, Xue-Peng; Liu, Zhi-Gou; Yi, Long-Tao; Sun, Wei-Yun; Li, Fang-Zou; Jiang, Bo-Wen; Ma, Yong-Zhong; Sun, Tian-Xi

    2015-12-10

    A combined shading system (CSS) consisting of a beam stop and a pinhole is proposed to be used between an ellipsoidal monocapillary (EM) and a conventional laboratory x-ray source to obtain an adjustable hollow-cone output beam for different experiments with no need for changing the EM. The CSS can change the incident x-ray beam on the EM by adjusting the position of the beam stop and the pinhole, with the corresponding change of the output beam of the EM. In this study, the adjustable hollow-cone output x-ray beam of an 80-mm-long EM with a CSS was studied in detail with a laboratory Cu x-ray generator with a focal spot diameter of 50 μm. The adjustable range of the focal spot size of the EM was from 8.6 to 58.7 μm. The adjustable range of the gain of the focal spot of the EM was from 0 to 1350. The beam divergence of the hollow-cone output beam of the EM ranged from 6 to 16.75 mrad. The illumination angle of the hollow-cone output beam of the EM ranged from 0 to 5.95 mrad. In addition, the potential application of the proposed adjusting method in testing the performance of the EM is briefly discussed.

  9. X-ray microscopy using grazing-incidence reflection optics

    International Nuclear Information System (INIS)

    Price, R.H.

    1981-01-01

    The Kirkpatrick-Baez microscopes are described along with their role as the workhorse of the x-ray imaging devices. This role is being extended with the development of a 22X magnification Kirkpatrick-Baez x-ray microscope with multilayer x-ray mirrors. These mirrors can operate at large angles, high x-ray energies, and have a narrow, well defined x-ray energy bandpass. This will make them useful for numerous experiments. However, where a large solid angle is needed, the Woelter microscope will still be necessary and the technology needed to build them will be useful for many other types of x-ray optics

  10. In situ micro-focused X-ray beam characterization with a lensless camera using a hybrid pixel detector

    International Nuclear Information System (INIS)

    Kachatkou, Anton; Marchal, Julien; Silfhout, Roelof van

    2014-01-01

    Position and size measurements of a micro-focused X-ray beam, using an X-ray beam imaging device based on a lensless camera that collects radiation scattered from a thin foil placed in the path of the beam at an oblique angle, are reported. Results of studies on micro-focused X-ray beam diagnostics using an X-ray beam imaging (XBI) instrument based on the idea of recording radiation scattered from a thin foil of a low-Z material with a lensless camera are reported. The XBI instrument captures magnified images of the scattering region within the foil as illuminated by the incident beam. These images contain information about beam size, beam position and beam intensity that is extracted during dedicated signal processing steps. In this work the use of the device with beams for which the beam size is significantly smaller than that of a single detector pixel is explored. The performance of the XBI device equipped with a state-of-the-art hybrid pixel X-ray imaging sensor is analysed. Compared with traditional methods such as slit edge or wire scanners, the XBI micro-focused beam characterization is significantly faster and does not interfere with on-going experiments. The challenges associated with measuring micrometre-sized beams are described and ways of optimizing the resolution of beam position and size measurements of the XBI instrument are discussed

  11. Evaluation of monoenergetic X-rays beams used in tomography

    International Nuclear Information System (INIS)

    Costa, Ernande Barbosa da; Lopes, Ricardo Tadeu; Ladeira, Carlos Luiz

    1996-01-01

    This paper describes the use of filter for the quasi monochromatization of the X-rays beam, and his utilization in tomography. The filters used may be classified as attenuators, high-pass and band-pass filters. 100 μm thin copper and 25-50 μm thin rhodium sheets, and also epoxy resin matrix and cadmium powder have been used as filters. The results show a qualitative comparison of the obtained images, and quantitative analysis of the linear attenuation coefficient behaviour compared with the simulated results in the literature

  12. Food Irradiation Using Electron Beams and X-Rays

    Science.gov (United States)

    Miller, Bruce

    2003-04-01

    In this presentation we will discuss the technology of food irradiation using electron accelerators. Food irradiation has generally come to describe the use of ionizing radiation to decrease the population of, or prevent the growth of, undesirable biological organisms in food. The many beneficial applications include insect disinfestation, sprouting inhibition, delayed ripening, and the enhanced safety and sterilization of fresh and frozen meat products, seafood, and eggs. With special regard to food safety, bacteria such as Salmonella enteridis, Listeria monocytogenes, Campylobacter jejuni and Escherichia coli serotype O157:H7 are the primary causes of food poisoning in industrialized countries. Ionizing doses in the range of only 1-5 kilogray (kGy) can virtually eliminate these organisms from food, without affecting the food's sensory and nutritional qualities, and without inducing radioactivity. The key elements of an accelerator-based irradiation facility include the accelerator system, a scanning system, and a material handling system that moves the product through the beam in a precisely controlled manner. Extensive radiation shielding is necessary to reduce the external dose to acceptable levels, and a safety system is necessary to prevent accidental exposure of personnel during accelerator operation. Parameters that affect the dose distribution must be continuously monitored and controlled with process control software. The choice of electron beam vs x-ray depends on the areal density (density times thickness) of the product and the anticipated mass throughput. To eliminate nuclear activation concerns, the maximum kinetic energy of the accelerator is limited by regulation to 10 MeV for electron beams, and 5 MeV for x-rays. From penetration considerations, the largest areal density that can be treated by double-sided electron irradiation at 10 MeV is about 8.8 g/cm2. Products having greater areal densities must be processed using more penetrating x-rays. The

  13. Errors in dual x-ray beam differential absorptiometry

    International Nuclear Information System (INIS)

    Bolin, F.; Preuss, L.; Gilbert, K.; Bugenis, C.

    1977-01-01

    Errors pertinent to the dual beam absorptiometry system have been studied and five areas are given in detail: (1) scattering, in which a computer analysis of multiple scattering shows little error due to this effect; (2) geometrical configuration effects, in which the slope of the sample is shown to influence the accuracy of the measurement; (3) Poisson variations, wherein it is shown that a simultaneous reduction can be obtained in both dosage and statistical error; (4) absorption coefficients, in which the effect of variation in absorption coefficient compilations is shown to have a critical effect on the interpretations of experimental data; and (5) filtering, wherein is shown the need for filters on dual beam systems using a characteristic x-ray output. A zero filter system is outlined

  14. X-ray framing camera for pulsed, high current, electron beam x-ray sources

    CERN Document Server

    Failor, B H; Riordan, j c; Lojewski, D Y

    2007-01-01

    High power x-ray sources built for nuclear weapons effects testing are evolving toward larger overall diameters and smaller anode cathode gaps. We describe a framing camera developed to measure the time-evolution of these 20-50 ns pulsed x-ray sources produced by currents in the 1.5-2.5 MA range and endpoint voltages between 0.2 and 1.5 MV. The camera has up to 4 frames with 5 ns gate widths; the frames are separated by 5 ns. The image data are recorded electronically with a gated intensified CCD camera and the data are available immediately following a shot. A fast plastic scintillator (2.1 ns decay time) converts the x-rays to visible light and, for high sensitivity, a fiber optic imaging bundle carries the light to the CCD input. Examples of image data are shown.

  15. Constancy check of beam quality in conventional diagnostic X-ray equipment

    International Nuclear Information System (INIS)

    Costa, Alessandro M.; Badin, Romulo S.; Leite, Marina S.; Caldas, Linda V.E.

    2008-01-01

    A tandem ionization chamber was developed for quality control programs of X-ray equipment used in conventional radiography and mammography. A methodology for the use of the tandem chamber in the constancy check of diagnostic X-ray beam qualities was established. The application at a medical X-ray imaging facility of this established methodology is presented. The use of the tandem chamber in the constancy check of diagnostic X-ray beam qualities is a useful method to control the performance of the X-ray equipment

  16. Combined evaluation of grazing incidence X-ray fluorescence and X-ray reflectivity data for improved profiling of ultra-shallow depth distributions.

    Science.gov (United States)

    Ingerle, D; Meirer, F; Pepponi, G; Demenev, E; Giubertoni, D; Wobrauschek, P; Streli, C

    2014-09-01

    The continuous downscaling of the process size for semiconductor devices pushes the junction depths and consequentially the implantation depths to the top few nanometers of the Si substrate. This motivates the need for sensitive methods capable of analyzing dopant distribution, total dose and possible impurities. X-ray techniques utilizing the external reflection of X-rays are very surface sensitive, hence providing a non-destructive tool for process analysis and control. X-ray reflectometry (XRR) is an established technique for the characterization of single- and multi-layered thin film structures with layer thicknesses in the nanometer range. XRR spectra are acquired by varying the incident angle in the grazing incidence regime while measuring the specular reflected X-ray beam. The shape of the resulting angle-dependent curve is correlated to changes of the electron density in the sample, but does not provide direct information on the presence or distribution of chemical elements in the sample. Grazing Incidence XRF (GIXRF) measures the X-ray fluorescence induced by an X-ray beam incident under grazing angles. The resulting angle dependent intensity curves are correlated to the depth distribution and mass density of the elements in the sample. GIXRF provides information on contaminations, total implanted dose and to some extent on the depth of the dopant distribution, but is ambiguous with regard to the exact distribution function. Both techniques use similar measurement procedures and data evaluation strategies, i.e. optimization of a sample model by fitting measured and calculated angle curves. Moreover, the applied sample models can be derived from the same physical properties, like atomic scattering/form factors and elemental concentrations; a simultaneous analysis is therefore a straightforward approach. This combined analysis in turn reduces the uncertainties of the individual techniques, allowing a determination of dose and depth profile of the implanted

  17. X-ray-ultraviolet beam splitters for the Michelson interferometer

    International Nuclear Information System (INIS)

    Delmotte, Franck; Ravet, Marie-Francoise; Bridou, Francoise; Varniere, Francoise; Zeitoun, Philippe; Hubert, Sebastien; Vanbostal, Laurent; Soullie, Gerard

    2002-01-01

    With the aim of realizing a Michelson interferometer working at 13.9 nm, we have developed a symmetrical beam splitter with multilayers deposited on the front and back sides of a silicon nitride membrane. On the basis of the experimental optical properties of the membrane, simulations have been performed to define the multilayer structure that provides the highest reflectivity-transmission product. Optimized Mo-Si multilayers have been successfully deposited on both sides of the membrane by use of the ion-beam sputtering technique, with a thickness-period reproducibility of 0.1 nm. Measurements by means of synchrotron radiation at 13.9 nm and at an angle of 45 deg. provide a reflectivity of 14.2% and a transmission of 15.2% for a 60% s-polarized light, close to the simulated values. Such a beam splitter has been used for x-ray laser Michelson interferometry at 13.9 nm. The first interferogram is discussed

  18. X-ray-ultraviolet beam splitters for the Michelson interferometer.

    Science.gov (United States)

    Delmotte, Franck; Ravet, Marie-Françoise; Bridou, Françoise; Varnière, Françoise; Zeitoun, Philippe; Hubert, Sébastien; Vanbostal, Laurent; Soullie, Gérard

    2002-10-01

    With the aim of realizing a Michelson interferometer working at 13.9 nm, we have developed a symmetrical beam splitter with multilayers deposited on the front and back sides of a silicon nitride membrane. On the basis of the experimental optical properties of the membrane, simulations have been performed to define the multilayer structure that provides the highest reflectivity-transmission product. Optimized Mo-Si multilayers have been successfully deposited on both sides of t he membrane by use of the ion-beam sputtering technique, with a thickness-period reproducibility of 0.1 nm. Measurements by means of synchrotron radiation at 13.9 nm and at an angle of 45 degrees provide a reflectivity of 14.2% and a transmission of 15.2% for a 60% s-polarized light, close to the simulated values. Such a beam splitter has been used for x-ray laser Michelson interferometry at 13.9 nm. The first interferogram is discussed.

  19. Partially coherent X-ray wavefront propagation simulations including grazing-incidence focusing optics.

    Science.gov (United States)

    Canestrari, Niccolo; Chubar, Oleg; Reininger, Ruben

    2014-09-01

    X-ray beamlines in modern synchrotron radiation sources make extensive use of grazing-incidence reflective optics, in particular Kirkpatrick-Baez elliptical mirror systems. These systems can focus the incoming X-rays down to nanometer-scale spot sizes while maintaining relatively large acceptance apertures and high flux in the focused radiation spots. In low-emittance storage rings and in free-electron lasers such systems are used with partially or even nearly fully coherent X-ray beams and often target diffraction-limited resolution. Therefore, their accurate simulation and modeling has to be performed within the framework of wave optics. Here the implementation and benchmarking of a wave-optics method for the simulation of grazing-incidence mirrors based on the local stationary-phase approximation or, in other words, the local propagation of the radiation electric field along geometrical rays, is described. The proposed method is CPU-efficient and fully compatible with the numerical methods of Fourier optics. It has been implemented in the Synchrotron Radiation Workshop (SRW) computer code and extensively tested against the geometrical ray-tracing code SHADOW. The test simulations have been performed for cases without and with diffraction at mirror apertures, including cases where the grazing-incidence mirrors can be hardly approximated by ideal lenses. Good agreement between the SRW and SHADOW simulation results is observed in the cases without diffraction. The differences between the simulation results obtained by the two codes in diffraction-dominated cases for illumination with fully or partially coherent radiation are analyzed and interpreted. The application of the new method for the simulation of wavefront propagation through a high-resolution X-ray microspectroscopy beamline at the National Synchrotron Light Source II (Brookhaven National Laboratory, USA) is demonstrated.

  20. Normal incidence X-ray mirror for chemical microanalysis

    Science.gov (United States)

    Carr, Martin J.; Romig, Jr., Alton D.

    1990-01-01

    A non-planar, focusing mirror, to be utilized in both electron column instruments and micro-x-ray fluorescence instruments for performing chemical microanalysis on a sample, comprises a concave, generally spherical base substrate and a predetermined number of alternating layers of high atomic number material and low atomic number material contiguously formed on the base substrate. The thickness of each layer is an integral multiple of the wavelength being reflected and may vary non-uniformly according to a predetermined design. The chemical analytical instruments in which the mirror is used also include a predetermined energy source for directing energy onto the sample and a detector for receiving and detecting the x-rays emitted from the sample; the non-planar mirror is located between the sample and detector and collects the x-rays emitted from the sample at a large solid angle and focuses the collected x-rays to the sample. For electron column instruments, the wavelengths of interest lie above 1.5 nm, while for x-ray fluorescence instruments, the range of interest is below 0.2 nm. Also, x-ray fluorescence instruments include an additional non-planar focusing mirror, formed in the same manner as the previously described m The invention described herein was made in the performance of work under contract with the Department of Energy, Contract No. DE-AC04-76DP00789, and the United States Government has rights in the invention pursuant to this contract.

  1. New X-ray beam position monitors with submicron resolution utilizing imaging of scattered X-rays at CHESS

    International Nuclear Information System (INIS)

    Revesz, Peter; Temnykh, Alexander B.; Pauling, Alan K.

    2011-01-01

    At CHESS' A, F and G wiggler beam lines three new video beam position monitors (VBPMs) have been commissioned. These new VBPMs utilize X-rays scattered from the graphite filter (A and F line) or from a beryllium window (G-line) as the white wiggler beam passes through them. As the X-rays scatter in all directions from the scattering medium, a slit camera creates an image of the beam's footprint on a fluorescent screen. This image is then viewed by a CCD camera and analyzed using a computer program to calculate the intensity centroid, the beam profile and integrated intensity. These data are delivered to the CHESS signal archiving system for storage and display. The new systems employ digital cameras. These cameras are free of the noise inherent to the analog systems with long video signal connections. As a result, the beam position data delivered by the new systems are more reliable and accurate as shown by beam position traces using different beam position monitors on the same beam line.

  2. Structure in defocused beams of x-ray mirrors: causes and possible solutions

    Science.gov (United States)

    Sutter, John P.; Alcock, Simon G.; Rust, Fiona; Wang, Hongchang; Sawhney, Kawal

    2014-09-01

    Grazing incidence mirrors are now a standard optic for focusing X-ray beams. Both bimorph and mechanically bendable mirrors are widely used at Diamond Light Source because they permit a wide choice of focal lengths. They can also be deliberately set out of focus to enlarge the X-ray beam, and indeed many beamline teams now wish to generate uniform beam spots of variable size. However, progress has been slowed by the appearance of fine structure in these defocused beams. Measurements showing the relationship between the medium-frequency polishing error and this structure over a variety of beam sizes will be presented. A theoretical model for the simulations of defocused beams from general mirrors will then be developed. Not only the figure error and its first derivative the slope error, but also the second derivative, the curvature error, must be considered. In conclusion, possible ways to reduce the defocused beam structure by varying the actuators' configuration and settings will be discussed.

  3. X-ray imaging with grazing-incidence microscopes developed for the LIL program

    International Nuclear Information System (INIS)

    Rosch, R.; Boutin, J. Y.; Le Breton, J. P.; Gontier, D.; Jadaud, J. P.; Reverdin, C.; Soullie, G.; Lidove, G.; Maroni, R.

    2007-01-01

    This article describes x-ray imaging with grazing-incidence microscopes, developed for the experimental program carried out on the Ligne d'Integration Laser (LIL) facility [J. P. Le Breton et al., Inertial Fusion Sciences and Applications 2001 (Elsevier, Paris, 2002), pp. 856-862] (24 kJ, UV--0.35 nm). The design includes a large target-to-microscope (400-700 mm) distance required by the x-ray ablation issues anticipated on the Laser MegaJoule facility [P. A. Holstein et al., Laser Part. Beams 17, 403 (1999)] (1.8 MJ) which is under construction. Two eight-image Kirkpatrick-Baez microscopes [P. Kirkpatrick and A. V. Baez J. Opt. Soc. Am. 38, 766 (1948)] with different spectral wavelength ranges and with a 400 mm source-to-mirror distance image the target on a custom-built framing camera (time resolution of ∼80 ps). The soft x-ray version microscope is sensitive below 1 keV and its spatial resolution is better than 30 μm over a 2-mm-diam region. The hard x-ray version microscope has a 10 μm resolution over an 800-μm-diam region and is sensitive in the 1-5 keV energy range. Two other x-ray microscopes based on an association of toroidal/spherical surfaces (T/S microscopes) produce an image on a streak camera with a spatial resolution better than 30 μm over a 3 mm field of view in the direction of the camera slit. Both microscopes have been designed to have, respectively, a maximum sensitivity in the 0.1-1 and 1-5 keV energy range. We present the original design of these four microscopes and their test on a dc x-ray tube in the laboratory. The diagnostics were successfully used on LIL first experiments early in 2005. Results of soft x-ray imaging of a radiative jet during conical shaped laser interaction are shown

  4. Energy dispersive detector for white beam synchrotron x-ray fluorescence imaging

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Matthew D., E-mail: Matt.Wilson@stfc.ac.uk; Seller, Paul; Veale, Matthew C. [Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell Campus,UK (United Kingdom); Connolley, Thomas [Diamond Light Source, I12 Beamline, Harwell Campus, Didcot, Oxfordshire (United Kingdom); Dolbnya, Igor P.; Malandain, Andrew; Sawhney, Kawal [Diamond Light Source, B16 Beamline, Harwell Campus, Didcot, Oxfordshire (United Kingdom); Grant, Patrick S.; Liotti, Enzo; Lui, Andrew [Department of Materials, University of Oxford Parks Road, Oxford (United Kingdom)

    2016-07-27

    A novel, “single-shot” fluorescence imaging technique has been demonstrated on the B16 beamline at the Diamond Light Source synchrotron using the HEXITEC energy dispersive imaging detector. A custom made furnace with 200µm thick metal alloy samples was positioned in a white X-ray beam with a hole made in the furnace walls to allow the transmitted beam to be imaged with a conventional X-ray imaging camera consisting of a 500 µm thick single crystal LYSO scintillator, mirror and lens coupled to an AVT Manta G125B CCD sensor. The samples were positioned 45° to the incident beam to enable simultaneous transmission and fluorescence imaging. The HEXITEC detector was positioned at 90° to the sample with a 50 µm pinhole 13 cm from the sample and the detector positioned 2.3m from pinhole. The geometric magnification provided a field of view of 1.1×1.1mm{sup 2} with one of the 80×80 pixels imaging an area equivalent to 13µm{sup 2}. Al-Cu alloys doped with Zr, Ag and Mo were imaged in transmission and fluorescence mode. The fluorescence images showed that the dopant metals could be simultaneously imaged with sufficient counts on all 80x80 pixels within 60 s, with the X-ray flux limiting the fluorescence imaging rate. This technique demonstrated that it is possible to simultaneously image and identify multiple elements on a spatial resolution scale ~10µm or higher without the time consuming need to scan monochromatic energies or raster scan a focused beam of X-rays. Moving to high flux beamlines and using an array of detectors could improve the imaging speed of the technique with element specific imaging estimated to be on a 1 s timescale.

  5. The quality of high-energy X-ray beams

    International Nuclear Information System (INIS)

    LaRiviere, P.D.

    1989-01-01

    Supplement 17 of the British Journal of Radiology is a survey of central-axis depth doses for radiotherapy machines, patterned largely on BJR Supplement 11 (1972). Inspection of high-energy X-ray depth doses for a 10 x 10 cm field at an SSD of 100 cm disclosed large differences between the two sets of data, especially for qualities above 8 MV, e.g. a depth dose of 80% at 10 cm is rated at about 19 MV according to BJR Supplement 11, and 23 MV according to BJR Supplement 17. It was found that Supplement 17 depth-dose data above 8 MV were erratic, but Supplement 11 data could be represented by an analytical expression, providing a unique means of assigning MV quality. It was also found that dose-weighted average energy of the filtered beam plotted smoothly against depth dose. For dosimetric purposes, it is suggested that this parameter be used as a true measure of beam quality, removing discrepancies introduced by the use of nominal MV for this purpose. (author)

  6. On the response of electronic personal dosimeters in constant potential and pulsed X-ray beams

    Energy Technology Data Exchange (ETDEWEB)

    Guimaraes, Margarete C.; Silva, Teogenes; Silva, Claudete R.E., E-mail: margaretecristinag@gmail.com [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Oliveira, Paulo Marcio C. de [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Anatomia e Imagem

    2015-07-01

    Electronic personal dosimeters (EPDs) based on solid state detectors have widely been used but some deficiencies in their response in pulsed radiation beams have been reported. Nowadays, there is not an international standard for pulsed X-ray beams for calibration or type testing of dosimeters. Irradiation conditions for testing the response of EPDs in both the constant potential and pulsed X-ray beams were established in CDTN. Three different types of EPDs were tested in different conditions in similar ISO and IEC X-ray qualities. Results stressed the need of performing additional checks before using EPDs in constant potential or pulsed X-rays. (author)

  7. Systems and methods for detecting an image of an object by use of an X-ray beam having a polychromatic distribution

    Science.gov (United States)

    Parham, Christopher; Zhong, Zhong; Pisano, Etta; Connor, Dean; Chapman, Leroy D.

    2010-06-22

    Systems and methods for detecting an image of an object using an X-ray beam having a polychromatic energy distribution are disclosed. According to one aspect, a method can include detecting an image of an object. The method can include generating a first X-ray beam having a polychromatic energy distribution. Further, the method can include positioning a single monochromator crystal in a predetermined position to directly intercept the first X-ray beam such that a second X-ray beam having a predetermined energy level is produced. Further, an object can be positioned in the path of the second X-ray beam for transmission of the second X-ray beam through the object and emission from the object as a transmitted X-ray beam. The transmitted X-ray beam can be directed at an angle of incidence upon a crystal analyzer. Further, an image of the object can be detected from a beam diffracted from the analyzer crystal.

  8. SU-F-I-76: Fluoroscopic X-Ray Beam Profiles for Spectra Incorporating Copper Filtration

    Energy Technology Data Exchange (ETDEWEB)

    Wunderle, K [Cleveland Clinic Foundation, Cleveland, OH (United States); Wayne State University School of Medicine, Detroit, MI (United States); Godley, A; Shen, Z; Dong, F [Cleveland Clinic Foundation, Cleveland, OH (United States); Rakowski, J [Wayne State University School of Medicine, Detroit, MI (United States)

    2016-06-15

    Purpose: The purpose of this investigation is to characterize and quantify X-ray beam profiles for fluoroscopic x-ray beam spectra incorporating spectral (copper) filtration. Methods: A PTW (Freiburg, Germany) type 60016 silicon diode detector and PTW MP3 water tank were used to measure X-ray beam profiles for 60, 80, 100 and 120 kVp x-ray beams at five different copper filtration thicknesses ranging from 0–0.9 mm at 22 and 42 cm fields of view and depths of 1, 5, and 10 cm in both the anode-cathode axis (inplane) and cross-plane directions. All measurements were acquired on a Siemens (Erlangen, Germany) Artis ZeeGo fluoroscope inverted from the typical orientation providing an x-ray beam originating from above the water surface with the water level set at 60 cm from the focal spot. Results: X-ray beam profiles for beam spectra without copper filtration compared well to previously published data by Fetterly et al. [Med Phys, 28, 205 (2001)]. Our data collection benefited from the geometric orientation of the fluoroscope, providing a beam perpendicular to the tank water surface, rather than through a thin side wall as did the previously mentioned study. Profiles for beams with copper filtration were obtained which have not been previously investigated and published. Beam profiles in the anode-cathode axis near the surface and at lower x-ray energy exhibited substantial heel effect, which became less pronounced at greater depth. At higher energy with copper filtration in the beam, the dose falloff out-of-field became less pronounced, as would be anticipated given higher scatter photon energy. Conclusion: The x-ray beam profile data for the fluoroscopic x-ray beams incorporating copper filtration are intended for use as reference data for estimating doses to organs or soft tissue, including fetal dose, involving similar beam qualities or for comparison with mathematical models.

  9. Ion beam induced surface graphitization of CVD diamond for x-ray beam position monitor applications

    International Nuclear Information System (INIS)

    Liu, Chian; Shu, D.; Kuzay, T.M.; Wen, L.; Melendres, C.A.; Argonne National Lab., IL

    1996-01-01

    The Advanced Photon Source at ANL is a third-generation synchrotron facility that generates powerful x-ray beams on its undulator beamlines. It is important to know the position and angle of the x- ray beam during experiments. Due to very high heat flux levels, several patented x-ray beam position monitors (XBPM) exploiting chemical vapor deposition (CVD) diamond have been developed. These XBPMs have a thin layer of low-atomic-mass metallic coating so that photoemission from the x rays generate a minute but measurable current for position determination. Graphitization of the CVD diamond surface creates a very thin, intrinsic and conducting layer that can stand much higher temperatures and minimal x-ray transmission losses compared to the coated metallic layers. In this paper, a laboratory sputter ion source was used to transform selected surfaces of a CVD diamond substrate into graphite. The effect of 1-5 keV argon ion bombardment on CVD diamond surfaces at various target temperatures from 200 to 500 C was studied using Auger electron spectroscopy and in-situ electrical resistivity measurements. Graphitization after the ion bombardment has been confirmed and optimum conditions for graphitization studied. Raman spectroscopy was used to identify the overall diamond structure in the bulk of CVD diamond substrate after the ion bombardments. It was found that target temperature plays an important role in stability and electrical conductivity of the irradiated CVD diamonds

  10. Response of the 'patient dose calibrator' chamber for incident positions and sizes of X-ray fields

    International Nuclear Information System (INIS)

    Oliveira, Cassio M.; Abrantes, Marcos Eugenio S.; Ferreira, Flavia C. Bastos; Lacerda, Marco A. de Souza; Alonso, Thessa C.; Silva, Teogenes A. da; Oliveira, Paulo Marcio C.

    2009-01-01

    The evaluation of patient doses is an important tool for optimizing radiodiagnostic medical procedures with conventional X-ray equipment and for improving the quality of the radiographic image. The Patient Dose Calibrator (PDC) chamber is a dosimetric instrument that is used in the evaluation of the air kerma-area product (P KA ) quantity aiming the reduction of patient doses. The objective this work was to study the P KA variation caused by different field incident positions and sizes of the X-ray beam on the PDC chamber. Results showed that the PDC chamber has repeatability lower than 0.6%, beam position dependence of 3% and linearity response within ± 6%; these characteristics are to be taken into account during evaluation of the radiological protection conditions of conventional x-ray equipment. (author)

  11. Diffraction of X-ray beams in capillary waveguides

    International Nuclear Information System (INIS)

    Kukhlevsky, S.V.; Flora, F.; Marinai, A.; Nyitray, G.; Ritucci, A.; Palladino, L.; Reale, A.; Tomassetti, G.

    2000-01-01

    Propagation of the soft X-ray radiation generated by a small-diameter incoherent source through the capillary plane waveguide which satisfies the multimode condition is studied using the Fresnel-Kirchhoff diffraction theory. The diffraction is manifested by appearance of the diffraction fringes, dark and light bands, in the far-field zone of the capillary output. Such a behaviour of the X-ray radiation is confirmed by our experimental data. The results give explanation for the interference effect recently observed in many experiments on the grazing reflections of X-rays in single and multiple capillary optics

  12. Dual X-ray absorptiometry: a comparison between fan beam and pencil beam scans

    Energy Technology Data Exchange (ETDEWEB)

    Blake, G.M.; Parker, J.C.; Buxton, F.M.A.; Fogelman, I. (Guy' s Hospital, London (United Kingdom). Dept. of Nuclear Medicine)

    1993-10-01

    The recent introduction of dual X-ray absorptiometry (DXA) systems with fan beam instead of conventional pencil beam scanning geometry represents a significant technical advance in bone densitometry. This report describes phantom and in-vivo studies of the effect of the change in beam configuration on DXA measurements. Fan beam and pencil beam measurements acquired on one of the new generation scanners, the Hologic QDR-2000, were compared with scans performed on an earlier pencil beam model, the Hologic QDR-1000. (author).

  13. Exposure reduction in general dental practice using digital x-ray imaging system for intraoral radiography with additional x-ray beam filter

    International Nuclear Information System (INIS)

    Shibuya, Hitoshi; Mori, Toshimichi; Hayakawa, Yoshihiko; Kuroyanagi, Kinya; Ota, Yoshiko

    1997-01-01

    To measure exposure reduction in general dental practice using digital x-ray imaging systems for intraoral radiography with additional x-ray beam filter. Two digital x-ray imaging systems, Pana Digital (Pana-Heraus Dental) and CDR (Schick Technologies), were applied for intraoral radiography in general dental practice. Due to the high sensitivity to x-rays, additional x-ray beam filters for output reduction were used for examination. An Orex W II (Osada Electric Industry) x-ray generator was operated at 60 kVp, 7 mA. X-ray output (air-kerma; Gy) necessary for obtaining clinically acceptable images was measured at 0 to 20 cm in 5 cm steps from the cone tip using an ionizing chamber type 660 (Nuclear Associates) and compared with those for Ektaspeed Plus film (Eastman Kodak). The Pana Digital system was used with the optional filter supplied by Pana-Heraus Dental which reduced the output to 38%. The exposure necessary to obtain clinically acceptable images was only 40% of that for the film. The CDR system was used with the Dental X-ray Beam Filter Kit (Eastman Kodak) which reduced the x-ray output to 30%. The exposure necessary to obtain clinically acceptable images was only 20% of that for the film. The two digital x-ray imaging systems, Pana Digital and CDR, provided large dose savings (60-80%) compared with Ektaspeed Plus film when applied for intraoral radiography in general dental practice. (author)

  14. Beam hardening: Analytical considerations of the effective attenuation coefficient of x-ray tomography

    International Nuclear Information System (INIS)

    Alles, J.; Mudde, R. F.

    2007-01-01

    Polychromatic x-ray beams traveling though material are prone to beam hardening, i.e., the high energy part of the incident spectrum gets over represented when traveling farther into the material. This study discusses the concept of a mean attenuation coefficient in a formal way. The total energy fluence is one-to-one related to the traveled distance in case of a polychromatic beam moving through a given, inhomogeneous material. On the basis of this one-to-one relation, it is useful to define a mean attenuation coefficient and study its decrease with depth. Our results are based on a novel parametrization of the energy dependence of the attenuation coefficient that allows for closed form evaluation of certain spectral integrals. This approach underpins the ad hoc semianalytical expressions given in the literature. An analytical model for the average attenuation coefficient is proposed that uses a simple fit of the attenuation coefficient as a function of the photon energy as input. It is shown that a simple extension of this model gives a rather good description of beam hardening for x-rays traveling through water

  15. Fluence thresholds for grazing incidence hard x-ray mirrors

    Czech Academy of Sciences Publication Activity Database

    Aquila, A.; Sobierajski, R.; Ozkan, C.; Hájková, Věra; Burian, Tomáš; Chalupský, Jaromír; Juha, Libor; Störmer, M.; Bajt, S.; Klepka, M.T.; Dlužewski, P.; Morawiec, K.; Ohashi, H.; Koyama, T.; Tono, K.; Inubushi, Y.; Yabashi, M.; Sinn, H.; Tschentscher, T.; Mancuso, A.P.; Gaudin, J.

    2015-01-01

    Roč. 106, č. 24 (2015), "241905-1"-"241905-5" ISSN 0003-6951 R&D Projects: GA ČR(CZ) GA14-29772S Grant - others:AVČR(CZ) M100101221 Institutional support: RVO:68378271 Keywords : XFEL * Free Electron Laser * damage threshold * X-ray optics Subject RIV: BH - Optics, Masers, Lasers Impact factor: 3.142, year: 2015

  16. Novel micro-reactor flow cell for investigation of model catalysts using in situ grazing-incidence X-ray scattering

    DEFF Research Database (Denmark)

    Kehres, Jan; Pedersen, Thomas; Masini, Federico

    2016-01-01

    -incidence small-angle X-ray scattering (GISAXS) in transmission through 10 µm-thick entrance and exit windows by using micro-focused beams. An additional thinning of the Pyrex glass reactor lid allows simultaneous acquisition of the grazing-incidence wide-angle X-ray scattering (GIWAXS). In situ experiments......The design, fabrication and performance of a novel and highly sensitive micro-reactor device for performing in situ grazing-incidence X-ray scattering experiments of model catalyst systems is presented. The design of the reaction chamber, etched in silicon on insulator (SIO), permits grazing...

  17. Design of parallel dual-energy X-ray beam and its performance for security radiography

    International Nuclear Information System (INIS)

    Kim, Kwang Hyun; Myoung, Sung Min; Chung, Yong Hyun

    2011-01-01

    A new concept of dual-energy X-ray beam generation and acquisition of dual-energy security radiography is proposed. Erbium (Er) and rhodium (Rh) with a copper filter were positioned in front of X-ray tube to generate low- and high-energy X-ray spectra. Low- and high-energy X-rays were guided to separately enter into two parallel detectors. Monte Carlo code of MCNPX was used to derive an optimum thickness of each filter for improved dual X-ray image quality. It was desired to provide separation ability between organic and inorganic matters for the condition of 140 kVp/0.8 mA as used in the security application. Acquired dual-energy X-ray beams were evaluated by the dual-energy Z-map yielding enhanced performance compared with a commercial dual-energy detector. A collimator for the parallel dual-energy X-ray beam was designed to minimize X-ray beam interference between low- and high-energy parallel beams for 500 mm source-to-detector distance.

  18. Laboratory-based micro-X-ray fluorescence setup using a von Hamos crystal spectrometer and a focused beam X-ray tube

    International Nuclear Information System (INIS)

    Kayser, Y.; Błachucki, W.; Dousse, J.-Cl.; Hoszowska, J.; Neff, M.; Romano, V.

    2014-01-01

    The high-resolution von Hamos bent crystal spectrometer of the University of Fribourg was upgraded with a focused X-ray beam source with the aim of performing micro-sized X-ray fluorescence (XRF) measurements in the laboratory. The focused X-ray beam source integrates a collimating optics mounted on a low-power micro-spot X-ray tube and a focusing polycapillary half-lens placed in front of the sample. The performances of the setup were probed in terms of spatial and energy resolution. In particular, the fluorescence intensity and energy resolution of the von Hamos spectrometer equipped with the novel micro-focused X-ray source and a standard high-power water-cooled X-ray tube were compared. The XRF analysis capability of the new setup was assessed by measuring the dopant distribution within the core of Er-doped SiO 2 optical fibers

  19. Laboratory-based micro-X-ray fluorescence setup using a von Hamos crystal spectrometer and a focused beam X-ray tube.

    Science.gov (United States)

    Kayser, Y; Błachucki, W; Dousse, J-Cl; Hoszowska, J; Neff, M; Romano, V

    2014-04-01

    The high-resolution von Hamos bent crystal spectrometer of the University of Fribourg was upgraded with a focused X-ray beam source with the aim of performing micro-sized X-ray fluorescence (XRF) measurements in the laboratory. The focused X-ray beam source integrates a collimating optics mounted on a low-power micro-spot X-ray tube and a focusing polycapillary half-lens placed in front of the sample. The performances of the setup were probed in terms of spatial and energy resolution. In particular, the fluorescence intensity and energy resolution of the von Hamos spectrometer equipped with the novel micro-focused X-ray source and a standard high-power water-cooled X-ray tube were compared. The XRF analysis capability of the new setup was assessed by measuring the dopant distribution within the core of Er-doped SiO2 optical fibers.

  20. Experimental study on hard X-ray generation of relativistic electron beams in azimuthal magnetic field

    CERN Document Server

    Fan Ya Jun; Qiu Aici

    2002-01-01

    Experimental study on hard X-ray generation was carried out on Flash 2 accelerator, with the method of relativistic electron beams transported in a low pressure gas via azimuthal magnetic field and interacted with Ta target. At 47 cm transporting distance, the measured areal integral of hard X-ray dose rate was 2.1 x 10 sup 1 sup 0 Gy centre dot cm sup 2 /s, total areal integral of hard X-ray dose was 1843 Gy centre dot cm sup 2 , and X-ray convert rate was 108 Gy centre dot cm sup 2 /kJ

  1. Evaluation device of diagnostic X-ray beam

    International Nuclear Information System (INIS)

    Pela, Carlos Alberto; Paula, Eldereis de; Bruco, Jose Luiz; Ghilardi Netto, Thomaz

    1996-01-01

    A device developed to determine the physical parameters useful to the evaluation of both dental and medical X-ray equipment is presented. Nine detectors connected each one to a signal amplifier are used. The amplifiers output has being connected to an analog to digital interface plugged in a PC-AT microcomputer. The X-ray pass through filters before reaching the detectors. The data collected by microcomputer are used to calculate the kVp and other factors as total tube filtration, waveform, half-value layer, exposure rate and exposure time

  2. Evaluation of the Beam Quality of Intraoral X-ray Equipment using Intraoral Standard Films

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Sub; Kwon, Hyok Rak; Sim, Woo Hyoun; Oh, Seung Hyoun; Lee, Ji Youn; Jeon, Kug Jin; Kim, Kee Deog; Park, Chang Seo [Dept. of Oral and Maxillofacial Radiology, College of Dentistry, Yensei University, Seoul (Korea, Republic of)

    2000-09-15

    This study was to evaluate the beam quality of intraoral X-ray equipment used at Yonsei University Dental Hospital (YUDH) using the half value layer (HVL) and the characteristic curve of intraoral standard X-ray film. The study was done using the intraoral X-ray equipment used at each clinical department at YUDH. Aluminum filter was used to determine the HVL. Intraoral standard film was used to get the characteristic curve of each intraoral X-ray equipment. Most of the HVLs of intraoral X-ray equipment were higher than the least recommended thickness, but the REX 601 model used at the operative dentistry department and the X-707 model used at the pediatric dentistry department had HVLs lower than the recommended thickness. The slopes of the characteristic curves of films taken using the PANPAS 601 model and REX 601 model at operative dentistry department, the X-70S model of prosthodontic dentistry department, and the REX 601 model at the student clinic were relatively low. HVL and the characteristic curve of X-ray film can be used to evaluate the beam quality of intraoral X-ray equipment. In order to get the best X-ray films with the least radiation exposure to patients and best diagnostic information in clinical dentistry, X-ray equipment should be managed in the planned and organized fashion.

  3. Evaluation of the Beam Quality of Intraoral X-ray Equipment using Intraoral Standard Films

    International Nuclear Information System (INIS)

    Lee, Sang Sub; Kwon, Hyok Rak; Sim, Woo Hyoun; Oh, Seung Hyoun; Lee, Ji Youn; Jeon, Kug Jin; Kim, Kee Deog; Park, Chang Seo

    2000-01-01

    This study was to evaluate the beam quality of intraoral X-ray equipment used at Yonsei University Dental Hospital (YUDH) using the half value layer (HVL) and the characteristic curve of intraoral standard X-ray film. The study was done using the intraoral X-ray equipment used at each clinical department at YUDH. Aluminum filter was used to determine the HVL. Intraoral standard film was used to get the characteristic curve of each intraoral X-ray equipment. Most of the HVLs of intraoral X-ray equipment were higher than the least recommended thickness, but the REX 601 model used at the operative dentistry department and the X-707 model used at the pediatric dentistry department had HVLs lower than the recommended thickness. The slopes of the characteristic curves of films taken using the PANPAS 601 model and REX 601 model at operative dentistry department, the X-70S model of prosthodontic dentistry department, and the REX 601 model at the student clinic were relatively low. HVL and the characteristic curve of X-ray film can be used to evaluate the beam quality of intraoral X-ray equipment. In order to get the best X-ray films with the least radiation exposure to patients and best diagnostic information in clinical dentistry, X-ray equipment should be managed in the planned and organized fashion.

  4. Micro-beam X-ray fluorescence and absorption imaging techniques at the IAEA Laboratories

    International Nuclear Information System (INIS)

    Wegrzynek, Dariusz; Markowicz, A.; Bamford, S.; Chinea-Cano, E.; Bogovac, M.

    2005-01-01

    X-ray tube based, micro-beam X-ray fluorescence scanning spectrometer has been equipped with two energy dispersive X-ray detectors. The two-detector configuration allows for simultaneous collection of X-ray fluorescence (XRF) and transmitted X-ray beam signals with a spatial resolution in the range of 10-50 μm, depending on the X-ray focussing element in use. The XRF signal is collected with a standard, liquid nitrogen cooled Si(Li) detector. The X-ray beam transmitted through the sample is acquired with a thermoelectrically cooled, silicon drift (SD) detector. The data acquisition is carried out in a fully automatic way under control of the SPECTOR-LOCATOR software. The software controls the scanning procedure and X-ray spectra acquisition during the scan. The energy dispersive X-ray spectra collected at every 'pixel' are stored for off-line processing. For selected regions of interest (ROI's), the element maps are constructed and displayed on-line. The spectrometer has been used for mapping elemental distributions and for performing 2D- and 3D-tomograpic imaging of minute objects in X-ray absorption and in X-ray fluorescence mode. A unique feature of the described system is simultaneous utilization of the two detectors, Si(Li) and SD, which adds new options for quantitative analysis and data interpretation. Examples of elemental mapping and 3D tomographic imaging as well as the advanced features of the SPECTOR-LOCATOR measurement control and data acquisition software are presented in this work

  5. Visualization of X-ray Beam Using CdWO4 Crystal for Macromolecular Crystallography

    Directory of Open Access Journals (Sweden)

    Kazimierz J. Gofron

    2011-12-01

    Full Text Available In synchrotron diffraction experiments, it is typically assumed that the X-ray beam at the sample position is uniform, stable and has dimensions that are controlled by the focus and slits settings. As might be expected, this process is much more complex. We present here an investigation of the properties of a synchrotron X-ray beam at the sample position. The X-ray beam is visualized with a single crystal scintillator that converts X-ray photons into visible light photons, which can be imaged using Structure Biology Center (SBC on-axis and off-axis microscope optics. The X-ray penetration is dependent on the composition of the scintillator (especially the effective Z, and X-ray energy. Several scintillators have been used to visualize X-ray beams. Here we compare CdWO4, PbWO4, Bi4Ge3O12, Y3Al5O12:Ce (YAG:Ce, and Gd2O2S:Tb (phosphor. We determined that scintillator crystals made of CdWO4 and similar high-Z materials are best suited for the energy range (7–20 keV and are most suitable for beam visualization for macromolecular crystallography applications. These scintillators show excellent absorption, optical, and mechanical properties.

  6. Single-shot beam-position monitor for x-ray free electron laser

    Science.gov (United States)

    Tono, Kensuke; Kudo, Togo; Yabashi, Makina; Tachibana, Takeshi; Feng, Yiping; Fritz, David; Hastings, Jerome; Ishikawa, Tetsuya

    2011-02-01

    We have developed an x-ray beam-position monitor for detecting the radiation properties of an x-ray free electron laser (FEL). It is composed of four PIN photodiodes that detect backscattered x-rays from a semitransparent diamond film placed in the beam path. The signal intensities from the photodiodes are used to compute the beam intensity and position. A proof-of-principle experiment at a synchrotron light source revealed that the error in the beam position is reduced to below 7 μm by using a nanocrystal diamond film prepared by plasma-enhanced chemical vapor deposition. Owing to high dose tolerance and transparency of the diamond film, the monitor is suitable for routine diagnostics of extremely intense x-ray pulses from the FEL.

  7. Effect of X-ray suppression system upon parameters of electrostatic accelerator ion beam

    Directory of Open Access Journals (Sweden)

    I. G. Ignat'ev

    2014-12-01

    Full Text Available Experimental study results are presented for a beam profile and emittance of an electrostatic accelerator “Sokol” before and after being equipped with magnet X-ray suppression system.

  8. Therapy imaging: Limitations of imaging with high energy x-ray beams

    International Nuclear Information System (INIS)

    Munro, P.; Rawlinson, J.A.; Fenster, A.

    1987-01-01

    One of the major problems in radiation therapy is ensuring that the correct region of the patient receives the prescribed x-ray treatment and that the surrounding tissues are spared. One way to identify patient positioning errors is to make an image using the radiotherapy treatment beam. The authors have examine4d two of the factors that can influence the quality of images made with high energy x-ray beams: (i) the size of the x-ray source, and; (ii) the signal-to-noise characteristics of the detectors used to form images with high energy x-ray beams. They have developed a novel method of measuring the source distributions for /sup 60/Co machines and linear accelerators and from the measurements have been able to obtain the modulation transfer functions of their x-ray sources. They also measured the modulation transfer functions (MTFs) and the noise power spectra (NPS) of the x-ray detectors. Based on these measurements, the authors conclude that images made with high energy x-ray beams are limited by film granularity and that improved images can be obtained by alternative detector systems

  9. White Beam, X-Ray, Energy-Dispersive Diffractometry using Synchrotron Radiation

    DEFF Research Database (Denmark)

    Gerward, Leif; Buras, B.; Olsen, J. Staun

    1978-01-01

    The special features of left double quote white right double quote beam X-ray energy-dispersive diffractometry using synchrotron radiation are discussed on the basis of experiments performed at the Deutsches Electronen-Synchrotron, DESY.......The special features of left double quote white right double quote beam X-ray energy-dispersive diffractometry using synchrotron radiation are discussed on the basis of experiments performed at the Deutsches Electronen-Synchrotron, DESY....

  10. Bipolar junction transistor as a detector for measuring in diagnostic X-ray beams

    Energy Technology Data Exchange (ETDEWEB)

    Cavalcanti, Francisco A.; Monte, David S.; Alves, Aline N.; Barros, Fabio R.; Santos, Marcus A.P.; Santos, Luiz A.P., E-mail: franciscoacavalcanti@gmail.com, E-mail: lasantos@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2013-07-01

    Photodiode and phototransistor are the most frequently used devices for measuring ionizing radiation in medical applications. The cited devices have the operating principle well known, however the bipolar junction transistor (BJT) is not a typical device used as a detector for measuring some physical quantities for diagnostic radiation. In fact, a photodiode, for example, has an area about 10 mm square and a BJT has an area which can be more than 10 thousands times smaller. The purpose of this paper is to bring a new technique to estimate some physical quantities or parameters in diagnostic radiation; for example, peak kilovoltage (kVp), deep dose measurements. The methodology for each type of evaluation depends on the energy range of the radiation and the physical quantity or parameter to be measured. Actually, some characteristics of the incident radiation under the device can be correlated with the readout signal, which is a function of the electrical currents in the electrodes of the BJT: Collector, Base and Emitter. Samples of BJT are classified and submitted to diagnostic X-ray beams. The results show that the BJT could be a new semiconductor sensor type for measuring either the ionizing radiation dose or some characteristics of diagnostic X-ray beams. (author)

  11. Grazing Incidence X-Ray Fluorescence of periodic structures – a comparison between X-ray Standing Waves and Geometrical Optics calculations.

    OpenAIRE

    Reinhardt Falk; Nowak Stanislaw H.; Beckhoff Burkhard; Dousse Jean-Claude; Schoengen Max

    2014-01-01

    Grazing incidence X-ray fluorescence spectra of nano-scaled periodic line structures were recorded at the four crystal monochromator beamline in the laboratory of the Physikalisch-Technische Bundesanstalt at the synchrotron radiation facility BESSY II. For different tilt angles between the lines and the plane of incidence of the monochromatic synchrotron radiation, spectral features are observed which can be understood and explained with calculations of the emerging X-ray standing wave (XSW) ...

  12. X-ray fluorescence analysis of thin films at glancing-incident and -takeoff angles

    International Nuclear Information System (INIS)

    Tsuji, K.; Sato, S.; Hirokawa, K.

    1995-01-01

    We have developed a new analytical method, Glancing-Incidence and -Takeoff X-Ray Fluorescence (GIT-XRF) method for the first time. Here, we present an idea for a thin-film analysis and a surface analysis by the GIT-XRF method. In this method, the dependence of the fluorescent x-ray intensity on takeoff angle is measured at various incident angles of the primary x-ray. Compared with a total reflection x-ray fluorescence method, the GIT-XRF method allows a detailed thin-film analysis, because the thin film is cross-checked by many experimental curves. Moreover, a surface-sensitive analysis is also possible by the GIT-XRF method. (author)

  13. Determination of the effective energy in X-rays standard beams, mammography level

    Energy Technology Data Exchange (ETDEWEB)

    Correa, Eduardo de Lima; Vivolo, Vitor; Potiens, Maria da Penha A., E-mail: Vivolo@ipen.b, E-mail: mppalbu@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    The X-rays beams used in diagnostic radiology are heterogeneous. This means that, in a radiological beam, it can be found photons with different energies. Because of that is common to work with the concept of effective energy. In this study the effective energy of an X-rays system used in instruments calibration was determined, as part of the mammography radiation qualities establishment. The procedure presented here was developed based on information found in the literature. The X-ray mass attenuation coefficients for aluminum, given by NIST web site, were used and the mathematical adjusts were done using the Origin 8.0 program. The results are part of the mammographic X-rays beams characteristics determination and it is important to keep the quality of this reference system. (author)

  14. 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%.

  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. Grazing Incidence X-ray Scattering and Diffraction

    Indian Academy of Sciences (India)

    IAS Admin

    tion between the incident plane wave and the medium is sufficiently weak, then the first Born approximation, can be applied. In this approximation, the scattered wave function ψ(r ) can be assumed to be the same as the incident plane wave and hence the scattering amplitude takes a simpler form f(kf ,ki) = ∫ dr ϱ(r )e iq.r.

  17. Production of X-ray transition radiation with relativistic electrons propagating at grazing incidence

    CERN Document Server

    Couillaud, C

    2002-01-01

    This paper is concerned with the production of X-ray transition radiation when a relativistic electron crosses the interface between two media of different permittivities at the grazing incidence. The production yields are derived analytically when a thick interface is considered and are compared with those obtained when the electron crosses the interface at normal incidence. The production of X-ray photons having an energy between two photoabsorption edges or close to a photoabsorption edge is also investigated. The main features of the transition radiation produced are then exhibited and it is shown that the intensity can be increased by many orders of magnitude. We also show that, at grazing incidence, the backward transition radiation has an intensity close to the forward emission one, contrary to the normal incidence case. The production of quasi-monochromatic radiation is also presented. Finally, the production of X-ray transition radiation using a multilayer radiator is considered and compared in both ...

  18. X-ray tube

    International Nuclear Information System (INIS)

    Webley, R.S.

    1975-01-01

    The object of the invention described is to provide an X-ray tube providing a scanned X-ray output which does not require a scanned electron beam. This is obtained by an X-ray tube including an anode which is rotatable about an axis, and a source of a beam of energy, for example an electron beam, arranged to impinge on a surface of the anode to generate X-radiation substantially at the region of incidence on the anode surface. The anode is rotatable about the axis to move the region of incidence over the surface. The anode is so shaped that the rotation causes the region of incidence to move in a predetermined manner relative to fixed parts of the tube so that the generated X-radiation is scanned in a predetermined manner relative to the tube. (UK)

  19. Differential Deposition for Surface Figure Corrections in Grazing Incidence X-Ray Optics

    Science.gov (United States)

    Ramsey, Brian D.; Kilaru, Kiranmayee; Atkins, Carolyn; Gubarev, Mikhail V.; Broadway, David M.

    2015-01-01

    Differential deposition corrects the low- and mid- spatial-frequency deviations in the axial figure of Wolter-type grazing incidence X-ray optics. Figure deviations is one of the major contributors to the achievable angular resolution. Minimizing figure errors can significantly improve the imaging quality of X-ray optics. Material of varying thickness is selectively deposited, using DC magnetron sputtering, along the length of optic to minimize figure deviations. Custom vacuum chambers are built that can incorporate full-shell and segmented Xray optics. Metrology data of preliminary corrections on a single meridian of full-shell x-ray optics show an improvement of mid-spatial frequencies from 6.7 to 1.8 arc secs HPD. Efforts are in progress to correct a full-shell and segmented optics and to verify angular-resolution improvement with X-ray testing.

  20. Design of grazing-incidence multilayer supermirrors for hard-X-ray reflectors

    DEFF Research Database (Denmark)

    Joensen, K. D.; Voutov, P.; Szentgyorgyi, A.

    1995-01-01

    -X-ray reflector and a hard-X-ray telescope) shows that an improved performance can be obtained. A multilayer whose bilayer thicknesses are given by a power law expression is found to provide the best solution; however, it is only slightly better than some of the adapted neutron designs......Extremely broadband grazing-incidence multilayers for hard-X-ray reflection can be obtained by a gradual change of the layer thicknesses down through the structure. Existing approaches for designing similar neutron optics, called supermirrors, are shown to provide respectable performance when...... applied to X-ray multilayers. However, none of these approaches consider the effects of imperfect layer interfaces and absorption in the overlying layers. Adaptations of neutron designs that take these effects into account are presented, and a thorough analysis of two specific applications (a single hard...

  1. Considerations on Beam Quality Control in MIT X-Ray FEL

    CERN Document Server

    Wang, Dong; Graves, William; Huang, Gang; Wang, Defa; Wu, Juhao; Zwart, Townsend

    2005-01-01

    The next generation of x-ray FEL requires very high quality electron beams for producing unprecedented x-ray radiations. In proposed x-ray FEL facilities, especially those that use multi-stage high gain high harmonic (HGHG) principle to obtain coherence in both transverse and longitudinal dimensions, the arrival timing of electron bunches must be very precise to ensure the seed laser overlap the desired sections of the electron bunch. A scheme is proposed to achieve 10s fs level of arrival timing control level.

  2. A water-cooled x-ray monochromator for using off-axis undulator beam

    International Nuclear Information System (INIS)

    Khounsary, A.; Maser, J.

    2000-01-01

    Undulator beamlines at third-generation synchrotrons x-ray sources are designed to use the high-brilliance radiation that is contained in the central cone of the generated x-ray beams. The rest of the x-ray beam is often unused. Moreover, in some cases, such as in the zone-plate-based microfocusing beamlines, only a small part of the central radiation cone around the optical axis is used. In this paper, a side-station branch line at the Advanced Photon Source that takes advantage of some of the unused off-axis photons in a microfocusing x-ray beamline is described. Detailed information on the design and analysis of a high-heat-load water-cooled monochromator developed for this beamline is provided

  3. Characterization and control of femtosecond electron and X-ray beams at free-electron lasers

    Energy Technology Data Exchange (ETDEWEB)

    Behrens, Christopher

    2012-11-15

    X-ray free-electron lasers (FELs) open up new frontiers in photon science, and in order to take full advantage of these unique accelerator-based light sources, the characterization and control of the femtosecond electron and X-ray beams is essential. Within this cumulative thesis, recent results achieved within the active research field of femtosecond electron and X-ray beams at FELs are reported.The basic principles of X-ray FELs are described, and concepts of longitudinal electron beam diagnostics with femtosecond accuracy are covered. Experimental results obtained with a transverse deflecting structure (TDS) and spectroscopy of coherent terahertz radiation are presented, and the suppression of coherent optical radiation effects, required for diagnostics utilizing a TDS, is demonstrated. Control of the longitudinal phase space by using multiple radio frequencies for longitudinal electron beam tailoring is presented, and a new technique of reversible electron beam heating with two TDSs is described. For the characterization of femtosecond X-ray pulses, a novel method based on dedicated longitudinal phase space diagnostics for electron beams is introduced, and recent measurements with a streaking technique using external terahertz fields are presented.

  4. Characterization and control of femtosecond electron and X-ray beams at free-electron lasers

    International Nuclear Information System (INIS)

    Behrens, Christopher

    2012-11-01

    X-ray free-electron lasers (FELs) open up new frontiers in photon science, and in order to take full advantage of these unique accelerator-based light sources, the characterization and control of the femtosecond electron and X-ray beams is essential. Within this cumulative thesis, recent results achieved within the active research field of femtosecond electron and X-ray beams at FELs are reported.The basic principles of X-ray FELs are described, and concepts of longitudinal electron beam diagnostics with femtosecond accuracy are covered. Experimental results obtained with a transverse deflecting structure (TDS) and spectroscopy of coherent terahertz radiation are presented, and the suppression of coherent optical radiation effects, required for diagnostics utilizing a TDS, is demonstrated. Control of the longitudinal phase space by using multiple radio frequencies for longitudinal electron beam tailoring is presented, and a new technique of reversible electron beam heating with two TDSs is described. For the characterization of femtosecond X-ray pulses, a novel method based on dedicated longitudinal phase space diagnostics for electron beams is introduced, and recent measurements with a streaking technique using external terahertz fields are presented.

  5. Nano-fabrication of diffractive optics for soft X-ray and atom beam focusing

    International Nuclear Information System (INIS)

    Rehbein, S.

    2002-01-01

    Nano-structuring processes are described for manufacturing diffractive optics for the condenser-monochromator set-up of the transmission X-ray microscope (TXM) and for the scanning transmission X-ray microscope (STXM) at the BESSY II electron storage ring in Berlin. Furthermore, a process for manufacturing free-standing nickel zone plates for helium atom beam focusing experiments is presented. (author)

  6. Long-term stability of beam quality and output of conventional X-ray units

    OpenAIRE

    Fukuda, Atsushi; Matsubara, Kosuke; Miyati, Toshiaki

    2015-01-01

    Conventional diagnostic X-ray units are used for radiographic imaging in many countries. For obtaining entrance surface doses, a numerical dose determination method has been applied in Japan. Although this technique is effective, it has to account for errors, particularly fluctuations, due to the beam quality and output of X-ray tubes. As a part of our quality control procedures, we recorded the entrance surface air kerma, tube voltage, and half-value layer measurements made for four diagnost...

  7. X-ray grazing incidence diffraction from multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Tixier, S.; Boeni, P.; Swygenhoven, H. van; Horisberger, M. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-09-01

    Grazing incidence scattering geometries using synchrotron radiation have been applied in order to characterise the roughness profiles and the structural coherence of multilayers. The lateral correlation length of the roughness profiles was evaluated using diffuse reflectivity in the `out of plane` geometry. This type of measurement is the only diffuse reflectivity technique allowing large lateral momentum transfer. It is typically suitable for correlation lengths smaller than 1000 A. The lateral structural coherence length of Ni{sub 3}Al/Ni multilayers as a function of the layer thickness was obtained by grazing incidence diffraction (GID). 3 figs., 1 ref.

  8. An experimental evaluation of monochromatic x-ray beam position monitors at diamond light source

    Energy Technology Data Exchange (ETDEWEB)

    Bloomer, Chris, E-mail: chris.bloomer@diamond.ac.uk; Rehm, Guenther; Dolbnya, Igor P. [Diamond Light Source Ltd, Oxfordshire (United Kingdom)

    2016-07-27

    Maintaining the stability of the X-ray beam relative to the sample point is of paramount importance for beamlines and users wanting to perform cutting-edge experiments. The ability to detect, and subsequently compensate for, variations in X-ray beam position with effective diagnostics has multiple benefits: a reduction in commissioning and start-up time, less ‘down-time’, and an improvement in the quality of acquired data. At Diamond Light Source a methodical evaluation of a selection of monochromatic X-ray Beam Position Monitors (XBPMs), using a range of position detection techniques, and from a range of suppliers, was carried out. The results of these experiments are presented, showing the measured RMS noise on the position measurement of each device for a given flux, energy, beam size, and bandwidth. A discussion of the benefits and drawbacks of each of the various devices and techniques is also included.

  9. An experimental evaluation of monochromatic x-ray beam position monitors at diamond light source

    International Nuclear Information System (INIS)

    Bloomer, Chris; Rehm, Guenther; Dolbnya, Igor P.

    2016-01-01

    Maintaining the stability of the X-ray beam relative to the sample point is of paramount importance for beamlines and users wanting to perform cutting-edge experiments. The ability to detect, and subsequently compensate for, variations in X-ray beam position with effective diagnostics has multiple benefits: a reduction in commissioning and start-up time, less ‘down-time’, and an improvement in the quality of acquired data. At Diamond Light Source a methodical evaluation of a selection of monochromatic X-ray Beam Position Monitors (XBPMs), using a range of position detection techniques, and from a range of suppliers, was carried out. The results of these experiments are presented, showing the measured RMS noise on the position measurement of each device for a given flux, energy, beam size, and bandwidth. A discussion of the benefits and drawbacks of each of the various devices and techniques is also included.

  10. Comparing different approaches to characterization of focused X-ray laser beams

    Czech Academy of Sciences Publication Activity Database

    Chalupský, Jaromír; Boháček, Pavel; Hájková, Věra; Hau-Riege, S.P.; Heimann, P.A.; Juha, Libor; Krzywinski, J.; Messerschmidt, M.; Moeller, S.P.; Nagler, B.; Rowen, M.; Schlotter, W.F.; Swiggers, M.L.; Turner, J.J.

    2011-01-01

    Roč. 631, č. 1 (2011), s. 130-133 ISSN 0168-9002 R&D Projects: GA AV ČR KAN300100702; GA MŠk LC510; GA MŠk(CZ) LC528; GA ČR GAP208/10/2302; GA MŠk LA08024; GA AV ČR IAAX00100903; GA MŠk(CZ) ME10046 Institutional research plan: CEZ:AV0Z10100523 Keywords : X-ray laser * X-ray ablation * beam focusing * beam characterization * beam profile measurement Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.207, year: 2011

  11. A multiple CCD X-ray detector and its first operation with synchrotron radiation X-ray beam

    International Nuclear Information System (INIS)

    Suzuki, Masayo; Yamamoto, Masaki; Kumasaka, Takashi; Sato, Kazumichi; Toyokawa, Hidenori; Aries, Ian F.; Jerram, Paul A.; Ueki, Tatzuo

    1999-01-01

    A 4x4 array structure of 16 identical CCD X-ray detector modules, called the multiple CCD X-ray detector system (MCCDX), was submitted to its first synchrotron radiation experiment at the protein crystallography station of the RIKEN beamline (BL45XU) at the SPring-8 facility. An X-ray diffraction pattern of cholesterol powder was specifically taken in order to investigate the overall system performance

  12. A multiple CCD X-ray detector and its first operation with synchrotron radiation X-ray beam

    CERN Document Server

    Suzuki, M; Kumasaka, T; Sato, K; Toyokawa, H; Aries, I F; Jerram, P A; Ueki, T

    1999-01-01

    A 4x4 array structure of 16 identical CCD X-ray detector modules, called the multiple CCD X-ray detector system (MCCDX), was submitted to its first synchrotron radiation experiment at the protein crystallography station of the RIKEN beamline (BL45XU) at the SPring-8 facility. An X-ray diffraction pattern of cholesterol powder was specifically taken in order to investigate the overall system performance.

  13. Investigation of chemical vapour deposition diamond detectors by X- ray micro-beam induced current and X-ray micro-beam induced luminescence techniques

    CERN Document Server

    Olivero, P; Vittone, E; Fizzotti, F; Paolini, C; Lo Giudice, A; Barrett, R; Tucoulou, R

    2004-01-01

    Tracking detectors have become an important ingredient in high-energy physics experiments. In order to survive the harsh detection environment of the Large Hadron Collider (LHC), trackers need to have special properties. They must be radiation hard, provide fast collection of charge, be as thin as possible and remove heat from readout electronics. The unique properties of diamond allow it to fulfill these requirements. In this work we present an investigation of the charge transport and luminescence properties of "detector grade" artificial chemical vapour deposition (CVD) diamond devices developed within the CERN RD42 collaboration, performed by means of X-ray micro-beam induced current collection (XBICC) and X-ray micro- beam induced luminescence (XBIL) techniques. XBICC technique allows quantitative estimates of the transport parameters of the material to be evaluated and mapped with micrometric spatial resolution. In particular, the high resolution and sensitivity of the technique has allowed a quantitati...

  14. Normal incidence X-ray telescope power spectra of X-ray emission from solar active regions. I - Observations. II - Theory

    Science.gov (United States)

    Gomez, Daniel O.; Martens, Petrus C. H.; Golub, Leon

    1993-01-01

    Fourier analysis is applied to very high resolution image of coronal active regions obtained by the Normal Incidence X-Ray Telescope is used to find a broad isotropic power-law spectrum of the spatial distribution of soft X-ray intensities. Magnetic structures of all sizes are present down to the resolution limit of the instrument. Power spectra for the X-ray intensities of a sample of topologically different active regions are found which fall off with increasing wavenumber as 1/k-cubed. A model is presented that relates the basic features of coronal magnetic fluctuations to the subphotospheric hydrodynamic turbulence that generates them. The model is used to find a theoretical power spectrum for the X-ray intensity which falls off with increasing wavenumber as 1/k-cubed. The implications of a turbulent regime in active regions are discussed.

  15. Measurement and simulation for a complementary imaging with the neutron and X-ray beams

    Directory of Open Access Journals (Sweden)

    Hara Kaoru Y.

    2017-01-01

    Full Text Available By using a composite source system, we measured radiographs of the thermal neutron and keV X-ray in the 45-MeV electron linear accelerator facility at Hokkaido University. The source system provides the alternative beam of neutron and X-ray by switching the production target onto the electron beam axis. In the measurement to demonstrate a complementary imaging, the detector based on a vacuum-tube type neutron color image intensifier was applied to the both beams for dual-purpose. On the other hand, for reducing background in a neutron transmission spectrum, test measurements using a gadolinium-type neutron grid were performed with a cold neutron source at Hokkaido University. In addition, the simulations of the neutron and X-ray transmissions for various substances were performed using the PHITS code. A data analysis procedure for estimating the substance of sample was investigated through the simulations.

  16. Measurement and simulation for a complementary imaging with the neutron and X-ray beams

    Science.gov (United States)

    Hara, Kaoru Y.; Sato, Hirotaka; Kamiyama, Takashi; Shinohara, Takenao

    2017-09-01

    By using a composite source system, we measured radiographs of the thermal neutron and keV X-ray in the 45-MeV electron linear accelerator facility at Hokkaido University. The source system provides the alternative beam of neutron and X-ray by switching the production target onto the electron beam axis. In the measurement to demonstrate a complementary imaging, the detector based on a vacuum-tube type neutron color image intensifier was applied to the both beams for dual-purpose. On the other hand, for reducing background in a neutron transmission spectrum, test measurements using a gadolinium-type neutron grid were performed with a cold neutron source at Hokkaido University. In addition, the simulations of the neutron and X-ray transmissions for various substances were performed using the PHITS code. A data analysis procedure for estimating the substance of sample was investigated through the simulations.

  17. Grazing exit versus grazing incidence geometry for x-ray absorption near edge structure analysis of arsenic traces

    International Nuclear Information System (INIS)

    Meirer, F.; Streli, C.; Wobrauschek, P.; Zoeger, N.; Pepponi, G.

    2009-01-01

    In the presented study the grazing exit x-ray fluorescence was tested for its applicability to x-ray absorption near edge structure analysis of arsenic in droplet samples. The experimental results have been compared to the findings of former analyses of the same samples using a grazing incidence (GI) setup to compare the performance of both geometries. Furthermore, the investigations were accomplished to gain a better understanding of the so called self-absorption effect, which was observed and investigated in previous studies using a GI geometry. It was suggested that a normal incidence-grazing-exit geometry would not suffer from self-absorption effects in x-ray absorption fine structure (XAFS) analysis due to the minimized path length of the incident beam through the sample. The results proved this assumption and in turn confirmed the occurrence of the self-absorption effect for GI geometry. Due to its lower sensitivity it is difficult to apply the GE geometry to XAFS analysis of trace amounts (few nanograms) of samples but the technique is well suited for the analysis of small amounts of concentrated samples

  18. Characteristics of x-ray beams in two commercial multidetector computed tomography simulators: Monte Carlo simulations.

    Science.gov (United States)

    Kim, Sangroh; Song, Haijun; Movsas, Benjamin; Chetty, Indrin J

    2012-01-01

    As multidetector computed tomography (MDCT) scanning is routinely performed for treatment planning in radiation oncology, understanding the characteristics of the MDCT x-ray beam is essential to accurately estimate patient dose. The purpose of this study is to characterize the x-ray beams of two commercial MDCT simulators widely used in radiation oncology by Monte Carlo (MC) simulations. X-ray tube systems of two wide bore MDCT scanners (GE LightSpeed RT 4 and Philips Brilliance Big Bore) were modeled in the BEAMNRC/EGSNRC MC system. All the tube components were modeled from targets to bowtie filters. To validate our MC models, the authors measured half-value layers (HVL) using aluminum sheets and multifunctional radiation detectors and compared them to those obtained from MC simulations for 120 kVp beams. The authors also compared x-ray spectra obtained from MC simulation to the data provided by manufacturers. Additionally, lateral/axial beam profiles were measured in-air using radiochromic films and compared to the MC results. To understand the scatter effect, the authors also derived the scatter-to-primary energy fluence ratio (SPR) profiles and calculated the total SPR for each CT system with the CT dose index (CTDI) head and body phantoms using the BEAMNRC system. The authors found that the HVL, x-ray spectrum and beam profiles of the MC simulations agreed well with the manufacturer-specified data within 1%-10% on average for both scanners. The total SPR were ranged from 7.8 to 13.7% for the head phantom and from 10.7 to 18.9% for the body phantom. The authors demonstrate the full MC simulations of two commercial MDCT simulators to characterize their x-ray beams. This study may be useful to establish a patient-specific dosimetry for the MDCT systems.

  19. Development of a normal incidence multilayer, imaging X-ray microscope

    International Nuclear Information System (INIS)

    Shealy, D.L.; Hoover, R.B.; Walker, A.B.C. Jr.; Barbee, T.W. Jr.

    1989-01-01

    This paper describes the design, analysis, and fabrication of a normal-incidence multilayer 20x Schwarzschild imaging X-ray microscope. The microscope is being fabricated using much of the technology implemented in the Multispectral Solar Telescope Array. Results of diffraction analysis show that better than 400 A spatial resolution in the object plane up to a 1-mm field of view can be achieved with 125 A radiation. Other microscope systems for use in conjunction with X-ray telescopes are analyzed and designed. 18 refs

  20. Cone beam x-ray luminescence computed tomography: a feasibility study.

    Science.gov (United States)

    Chen, Dongmei; Zhu, Shouping; Yi, Huangjian; Zhang, Xianghan; Chen, Duofang; Liang, Jimin; Tian, Jie

    2013-03-01

    The appearance of x-ray luminescence computed tomography (XLCT) opens new possibilities to perform molecular imaging by x ray. In the previous XLCT system, the sample was irradiated by a sequence of narrow x-ray beams and the x-ray luminescence was measured by a highly sensitive charge coupled device (CCD) camera. This resulted in a relatively long sampling time and relatively low utilization of the x-ray beam. In this paper, a novel cone beam x-ray luminescence computed tomography strategy is proposed, which can fully utilize the x-ray dose and shorten the scanning time. The imaging model and reconstruction method are described. The validity of the imaging strategy has been studied in this paper. In the cone beam XLCT system, the cone beam x ray was adopted to illuminate the sample and a highly sensitive CCD camera was utilized to acquire luminescent photons emitted from the sample. Photons scattering in biological tissues makes it an ill-posed problem to reconstruct the 3D distribution of the x-ray luminescent sample in the cone beam XLCT. In order to overcome this issue, the authors used the diffusion approximation model to describe the photon propagation in tissues, and employed the sparse regularization method for reconstruction. An incomplete variables truncated conjugate gradient method and permissible region strategy were used for reconstruction. Meanwhile, traditional x-ray CT imaging could also be performed in this system. The x-ray attenuation effect has been considered in their imaging model, which is helpful in improving the reconstruction accuracy. First, simulation experiments with cylinder phantoms were carried out to illustrate the validity of the proposed compensated method. The experimental results showed that the location error of the compensated algorithm was smaller than that of the uncompensated method. The permissible region strategy was applied and reduced the reconstruction error to less than 2 mm. The robustness and stability were then

  1. A Study on Mono-energetic Beam Source Using Characteristic X-ray for Substance Identification System

    International Nuclear Information System (INIS)

    Lee, Hwan Soo

    2009-02-01

    A new mono-energetic beam source was developed by using characteristic X-ray for improving performance of the substance identification system. Most of inspection systems use X-ray tubes for their source modules. However, the broad energy spectrum of X-ray tube causes an increase of uncertainty. In this study, it was found that mono-energetic beam sources can be generated by using X-ray tube and the designed target filter assembly. In order to investigate the monoenergetic beam source, the sensitivity study was conducted with a series of different X-ray tube potentials, radiator and filter materials using Monte Carlo simulation. The developed beam sources have a mono-energy peak at 69 keV, 78 keV and 99 keV, and they are named as characteristic X-ray beam BEAM69, BEAM78 and BEAM99, respectively. The characteristic X-ray beam intensity was over thirty three times more than that of hardening beam used previous work at Hanyang University. And BEAM69 and BEAM99 were applied to the substance identification system as a source. The relative error between results of characteristic X-ray beams and 69 keV and 99 keV photons was about 2% on the average for five unknown materials. In comparison with experiment results by using hardening beam, characteristic X-ray beam achieves better accuracy which is about 6.46 % on the average. Hence, it is expected that the developed characteristic X-ray beam source helps lower uncertainty of the inspection system, and the inspection time will be reduced considerably due to its high beam intensity

  2. Providing Bright-Hard X-ray Beams from a Lower Energy Light Source

    Science.gov (United States)

    Robin, David

    2002-04-01

    At the Advanced Light Source (ALS) there had been an increasing demand for more high brightness harder X-ray sources in the 7 to 40 KeV range. In response to that demand, the ALS storage ring was modified in August 2001. Three 1.3 Tesla normal conducting bending magnets were removed and replaced with three 5 Tesla superconducting magnets (Superbends). The radiation produced by these Superbends is an order of magnitude higher in photon brightness and flux at 12 keV than the 1.3 Tesla bends, making them excellent sources of harder x-rays for protein crystallography and other harder x-ray applications. At the same time the Superbends do not compromise the performance of the facility in the UV and Soft X-ray regions of the spectrum. The Superbends will eventually feed 12 new x-ray beam lines greatly enhancing the facility's capacity in the hard x-ray region. The Superbend project is the biggest upgrade to the ALS storage ring since the ring was commissioned in 1993. In this paper we present, a history of the project, details of the magnet, installation, commissioning, and resulting performance of the ALS with Superbends.

  3. Diamond monochromator for high heat flux synchrotron x-ray beams

    International Nuclear Information System (INIS)

    Khounsary, A.M.; Smither, R.K.; Davey, S.; Purohit, A.

    1992-12-01

    Single crystal silicon has been the material of choice for x-ray monochromators for the past several decades. However, the need for suitable monochromators to handle the high heat load of the next generation synchrotron x-ray beams on the one hand and the rapid and on-going advances in synthetic diamond technology on the other make a compelling case for the consideration of a diamond mollochromator system. In this Paper, we consider various aspects, advantage and disadvantages, and promises and pitfalls of such a system and evaluate the comparative an monochromator subjected to the high heat load of the most powerful x-ray beam that will become available in the next few years. The results of experiments performed to evaluate the diffraction properties of a currently available synthetic single crystal diamond are also presented. Fabrication of diamond-based monochromator is within present technical means

  4. Simulations of X-ray synchrotron beams using the EGS4 code system in medical applications

    International Nuclear Information System (INIS)

    Orion, I.; Henn, A.; Sagi, I.; Dilmanian, F.A.; Pena, L.; Rosenfeld, A.B.

    2001-01-01

    X-ray synchrotron beams are commonly used in biological and medical research. The availability of intense, polarized low-energy photons from the synchrotron beams provides a high dose transfer to biological materials. The EGS4 code system, which includes the photoelectron angular distribution, electron motion inside a magnetic field, and the LSCAT package, found to be the appropriate Monte Carlo code for synchrotron-produced X-ray simulations. The LSCAT package was developed in 1995 for the EGS4 code to contain the routines to simulate the linear polarization, the bound Compton, and the incoherent scattering functions. Three medical applications were demonstrated using the EGS4 Monte Carlo code as a proficient simulation code system for the synchrotron low-energy X-ray source. (orig.)

  5. A compact and portable X-ray beam position monitor using Medipix3

    Science.gov (United States)

    Rico-Alvarez, O.; Kachatkou, A.; Marchal, J.; Willis, B.; Sawhney, K.; Tartoni, N.; van Silfhout, R. G.

    2014-12-01

    The present work reports on the design and implementation of a novel portable X-ray beam diagnostics (XBPM) device. The device is transparent to the X-ray beam and provides real-time measurements of beam position, intensity, and size. The measurement principle is based on a pinhole camera which records scattered radiation from a Kapton foil which is placed in the beam path. The use of hybrid detectors (Medipix3) that feature a virtually noiseless readout system with capability of single photon detection and energy resolving power enables the diagnostics with a better resolution and higher sensitivity compared to the use of traditional indirect X-ray detection schemes. We describe the detailed system design, which consists of a vacuum compatible focal plane sensor array, a sensor conditioning and readout board and a heterogeneous data processing unit, which also acts as a network server that handles network communications with clients. The readout protocol for the Medipix3 sensor is implemented using field programmable gate array (FPGA) logic resulting in a versatile and scalable system that is capable of performing advanced functions such as data compression techniques and feature extraction. For the system performance measurements, we equipped the instrument with a single Medipix3 die, bump bonded to a Si sensor, rather than four for which it was designed. Without data compression, it is capable of acquiring magnified images and profiles of synchrotron X-ray beams at a transfer rate through Ethernet of 27 frames/s for one Medipix3 die.

  6. Energy dependence evaluation of a ZnO detector for diagnostic X-ray beam

    International Nuclear Information System (INIS)

    Valença, C.P.V.; Silveira, M.A.L.; Macedo, M.A.; Santos, M.A.

    2015-01-01

    In the last decades the international organizations of human health and radiation protection have recommended certain care for using X-ray as a diagnosis tool. The current concern is to avoid any type of radiological accident or overdose to the patient. This can be done assessing the parameters of the X-ray equipment and there are various types of detectors available for that: ionizing chamber, semiconductor devices, etc. These detectors must be calibrated so that they can be used for any energy range and such a procedure is correlated with what is called the energy dependence of the detector. In accordance with the stated requirements of IEC 61267, the standard radiation quality beams and irradiation conditions (RQRs) are the tools and techniques for calibrating diagnostic X-Ray instruments and detectors. The purpose of this work is to evaluate the behavior of the energy dependence of a detector fabricated from a zinc oxide (ZnO) nanofilm. A Pantak industrial X-ray equipment was used to generate the RQR radiation quality beams and test three ZnO detector samples. A 6430 sub-femto-ammeter, Keithley, was used to bias the ZnO detector and simultaneously perform the output readings. The results showed that the ZnO device has some increase in its sensitivity to the ionizing radiation as the X-ray effective energy decreases unlike other types of semiconductor electronic devices typically used as an X-ray detector. We can be concluded that, after calibration, the ZnO device can be used as a diagnostic X-ray detector. (author)

  7. X-ray beam splitting design for concurrent imaging at hard X-ray FELs and synchrotron facilities

    Czech Academy of Sciences Publication Activity Database

    Oberta, Peter; Mokso, R.

    2013-01-01

    Roč. 729, NOV (2013), s. 85-89 ISSN 0168-9002 R&D Projects: GA MPO FR-TI1/412 Institutional research plan: CEZ:AV0Z10100522 Keywords : diffractive-refractive optics * hard X-ray FEL * X-ray imaging Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.316, year: 2013 http://www.sciencedirect.com/science/article/pii/S0168900213009613

  8. X-ray spectroscopy of highly-ionized atoms in an electron beam ion trap (EBIT)

    International Nuclear Information System (INIS)

    Marrs, R.E.; Bennett, C.; Chen, M.H.

    1988-01-01

    An Electron Beam Ion Trap at Lawrence Livermore National Laboratory is being used to produce and trap very-highly-charged-ions (q /le/ 70+) for x-ray spectroscopy measurements. Recent measurements of dielectronic recombination, electron impact excitation and transition energies are presented. 15 refs., 12 figs., 1 tab

  9. Dosimetry and narrow X-ray beams, produced by particle linear accelerator for use in radiosurgery

    International Nuclear Information System (INIS)

    Campos, J.C.F.; Vizeu, D.M.

    1987-01-01

    The principal characteristics of dosimetry and narrow X-ray beams(4Mv) monitoring are investigated for use in estereotatic radiosurgery. An additional collimator system and a estereotatic system (Leksell type) are presented. Dosimetric parameters like tissue-air ratio, peak scatter factor, isodose curves are studied. (M.A.C.) [pt

  10. X-ray Radiation Mechanisms and the Beaming Effect of Hot Spots ...

    Indian Academy of Sciences (India)

    Astr. (2011) 32, 193–196 c Indian Academy of Sciences. X-ray Radiation Mechanisms and the Beaming Effect of Hot Spots and Knots in AGN Jets. Jin Zhang1,∗. , Jin-Ming Bai2, Liang Chen2 & Enwei Liang3. 1College of Physics and Electronic Engineering, Guangxi Teachers Education University,. Nanning 530001, China.

  11. Bessel spatial profile of a soft x-ray laser beam

    Czech Academy of Sciences Publication Activity Database

    Tissandier, F.; Sebban, S.; Ribière, M.; Gautier, J.; Zeitoun, Ph.; Lambert, G.; Goddet, J.P.; Burgy, F.; Valentin, C.; Rousse, A.; Nejdl, Jaroslav; Mocek, Tomáš; Maynard, G.

    2010-01-01

    Roč. 97, č. 23 (2010), 231106/1-231106/3 ISSN 0003-6951 Grant - others:AVČR(CZ) M100100911 Institutional research plan: CEZ:AV0Z10100523 Keywords : soft x-ray laser * beam transverse profile * far-field profile measurment * high-order harmonic Subject RIV: BH - Optics, Masers, Lasers Impact factor: 3.820, year: 2010

  12. The perceptibility of variations in total x-ray beam filtration as evidenced on radiographs

    International Nuclear Information System (INIS)

    Williamson, B.D.P.

    1983-01-01

    The use of filtration in the primary x-ray beam has long been a standard procedure in controlling radiation doses to patients in diagnostic radiology, particularly surface doses. For lightly filtered beams, the addition of further filtration effectively removes softer beam components which otherwise would be absorbed within the patient. The amount and quality of radiation reaching the film is changed only slightly. Thus the first increments of filtration added to diagnostic x-ray beams require little or no change in exposure factors. With further filtration, however, the penetration of the beam increases and a greater proportion is transmitted through the patient to the film. The image contrast is reduced. Simultaneously the useful beam intensity is reduced to the extent that compensating mAs increases begin to be required to maintain constant optical density in the radiograph. When these compensatory adjustments are made it is possible to examine the relationship between total filtration and its effects on radiographic appearance, which should be seen as variations in contrast or penetration. This report is of an exploratory study of the perceptibility to radiographers of these changes in radiographic appearance caused by variations in x-ray beam filtration. (auth)

  13. An iterative reconstruction algorithm in cone beam geometry: simulation and application in X-ray microtomography

    International Nuclear Information System (INIS)

    Zolfaghari, A.

    1996-01-01

    An X-ray microtomograph has been built in our laboratory from a conventional scanning electron microscope. An algorithm based on algebraic reconstruction techniques (ART) has been developed to reconstruct the internal structure of the imaged object. This algorithm takes into account the diverging nature of the X-ray beam. In this paper we explain the reconstruction algorithm and we analyse the quality of the reconstructed objects in terms of signal-to-noise ratio (SNR), spatial resolution and cross-entropy. (orig.)

  14. On the Alignment and Focusing of the Marshall Grazing Incidence X-ray Spectrometer (MaGIXS)

    Science.gov (United States)

    Champey, Patrick; Winebarger, Amy; Kobayashi, Ken; Savage, Sabrina; Cirtain, Jonathan; Cheimets, Peter; Hertz, Edward; Golub, Leon; Ramsey, Brian; McCracken, Jeff

    2016-01-01

    The Marshall Grazing Incidence X-ray Spectrometer (MaGIXS) is a NASA sounding rocket instrument that is designed to observe soft X-ray emissions from 24 - 6.0 A (0.5 - 2.0 keV energies) in the solar atmosphere. For the rst time, high-temperature, low-emission plasma will be observed directly with 5 arcsecond spatial resolution and 22 mA spectral resolution. The unique optical design consists of a Wolter - I telescope and a 3-optic grazing- incidence spectrometer. The spectrometer utilizes a nite conjugate mirror pair and a blazed planar, varied line spaced grating, which is directly printed on a silicon substrate using e-beam lithography. The grating design is being nalized and the grating will be fabricated by the Massachusetts Institute of Technology (MIT) and Izentis LLC. Marshall Space Flight Center (MSFC) is producing the nickel replicated telescope and spectrometer mirrors using the same facilities and techniques as those developed for the ART-XC and FOXSI mirrors. The Smithsonian Astrophysical Observatory (SAO) will mount and align the optical sub-assemblies based on previous experience with similar instruments, such as the Hinode X-Ray Telescope (XRT). The telescope and spectrometer assembly will be aligned in visible light through the implementation of a theodolite and reference mirrors, in addition to the centroid detector assembly (CDA) { a device designed to align the AXAF-I nested mirrors. Focusing of the telescope and spectrometer will be achieved using the X-ray source in the Stray Light Facility (SLF) at MSFC. We present results from an alignment sensitivity analysis performed on the on the system and we also discuss the method for aligning and focusing MaGIXS.

  15. The effect of beam-driven return current instability on solar hard X-ray bursts

    Science.gov (United States)

    Cromwell, D.; McQuillan, P.; Brown, J. C.

    The problem of electrostatic wave generation by a return current driven by a small area electron beam during solar hard X-ray bursts is discussed. The marginal stability method is used to solve numerically the electron and ion heating equations for a prescribed beam current evolution. When ion-acoustic waves are considered, the method appears satisfactory and, following an initial phase of Coulomb resistivity in which Te/T sub i rise, predicts a rapid heating of substantial plasma volumes by anomalous ohmic dissipation. This hot plasma emits so much thermal bremsstrahlung that, contrary to previous expectations, the unstable beam-plasma system actually emits more hard X-rays than does the beam in the purely collisional thick target regime relevant to larger injection areas. Inclusion of ion-cyclotron waves results in ion-acoustic wave onset at lower Te/T sub i and a marginal stability treatment yields unphysical results.

  16. Dose properties of x-ray beams produced by laser-wakefield-accelerated electrons

    International Nuclear Information System (INIS)

    Kainz, K K; Hogstrom, K R; Antolak, J A; Almond, P R; Bloch, C D

    2005-01-01

    Given that laser wakefield acceleration (LWFA) has been demonstrated experimentally to accelerate electron beams to energies beyond 25 MeV, it is reasonable to assess the ability of existing LWFA technology to compete with conventional radiofrequency linear accelerators in producing electron and x-ray beams for external-beam radiotherapy. We present calculations of the dose distributions (off-axis dose profiles and central-axis depth dose) and dose rates of x-ray beams that can be produced from electron beams that are generated using state-of-the-art LWFA. Subsets of an LWFA electron energy distribution were propagated through the treatment head elements (presuming an existing design for an x-ray production target and flattening filter) implemented within the EGSnrc Monte Carlo code. Three x-ray energy configurations (6 MV, 10 MV and 18 MV) were studied, and the energy width ΔE of the electron-beam subsets varied from 0.5 MeV to 12.5 MeV. As ΔE increased from 0.5 MeV to 4.5 MeV, we found that the off-axis and central-axis dose profiles for x-rays were minimally affected (to within about 3%), a result slightly different from prior calculations of electron beams broadened by scattering foils. For ΔE of the order of 12 MeV, the effect on the off-axis profile was of the order of 10%, but the central-axis depth dose was affected by less than 2% for depths in excess of about 5 cm beyond d max . Although increasing ΔE beyond 6.5 MeV increased the dose rate at d max by more than 10 times, the absolute dose rates were about 3 orders of magnitude below those observed for LWFA-based electron beams at comparable energies. For a practical LWFA-based x-ray device, the beam current must be increased by about 4-5 orders of magnitude. (note)

  17. Analysis of mesoporous thin films by X-ray reflectivity, optical reflectivity and grazing incidence small angle X-ray scattering

    International Nuclear Information System (INIS)

    Gibaud, A.; Dourdain, S.; Vignaud, G.

    2006-01-01

    It is well-established that X-ray reflectivity (XR) is an invaluable tool to investigate the structure of thin films. Indeed, this technique provides under correct analysis, the electron density profile of thin films in the direction perpendicular to the substrate. For thin films that exhibit lateral ordering at the nanometer scale, grazing incidence small angle X-ray scattering (GISAXS) ideally complements the XR technique to measure the scattering in off-specular directions. As typical examples, XR and GISAXS data of mesoporous silica thin films and porous materials are presented. The analysis of the XR curve allows to determine the porosity of the film. We also show that the combination of X-ray and visible optical reflection provides information about the index of refraction of thin films. Finally we report how capillary condensation of water can be monitored by XR and GISAXS

  18. Development, Beam characterization and chromosomal effectiveness of X-rays of RBC characteristic X-ray generator

    International Nuclear Information System (INIS)

    Endo, Satoru; Hoshi, Masaharu; Takada, Jun; Takatsuji, Toshihiro; Ejima, Yosuke; Saigusa, Shin; Tachibana, Akira; Sasaki, Masao S.

    2006-01-01

    A characteristic hot-filament type X-ray generator was constructed for irradiation of cultured cells. The source provides copper K, iron K, chromium K, molybdenum L, aluminium K and carbon K shell characteristic X-rays. When cultured mouse m5S cells were irradiated and frequencies of dicentrics were fitted to a linear-quadratic model, Y=αD+βD 2 , the chromosomal effectiveness was not a simple function of photon energy. The α-terms increased with the decrease of the photon energy and then decreased with further decrease of the energy with an inflection point at around 10 keV. The β-terms stayed constant for the photon energy down to 10 keV and then increased with further decrease of energy. Below 10 keV, the relative biological effectiveness (RBE) at low doses was proportional to the photon energy, which contrasted to that for high energy X- or γ-rays where the RBE was inversely related with the photon energy. The reversion of the energy dependency occurred at around 1-2 Gy, where the RBE of soft X-rays was insensitive to X-ray energy. The reversion of energy-RBE relation at a moderate dose may shed light on the controversy on energy dependency of RBE of ultrasoft X-rays in cell survival experiments. (author)

  19. Study of a new portable x-ray source with micro-beam

    Science.gov (United States)

    Wang, Kaige; Li, Ji; Yang, Qinlao; Guo, Jinchuan; Guo, Baoping; Kuo, Xiaomei; Zhou, Junlan; Niu, Hanben

    2006-02-01

    A novel X-ray source with micro-beam has been studied in theory and experiment. The source is composed of three portions: LaB 6 crystal cathode electron gun emitting system, electrostatic focusing system, and permutable metal target system. The electronic current emitted by the electron-gun are controlled by modulating cathode temperature and Wehnelt grid voltage and ratio D w/H, two-equal-radius-cylinder-electrodes focusing system concentrates electron beam, the X-ray photons are irradiated by high energy electron beam bombarding the metal target. The new x-ray source's general-purpose capabilities such as continuous radiation and pulse radiation, focus size and luminance, are also tested. When the temperature of LaB6 cathode is about 1900K and partial pressures being kept below 10 -7 torr, the minimal focus diameter is merely about 10 microns. The new micro focus x-ray source has other lots of advantages such as economy, safety and facility.

  20. Single-shot beam profile diagnostics for x-ray FEL's using gas fluorescence

    Science.gov (United States)

    Feng, Yiping; Zhu, Diling; Weninger, Clemens; Alonso-Mori, Roberto; Chollet, Matthieu; Damiani, Daniel S.; Glownia, James M.; Hastings, Jerome B.; Nelson, Silke; Song, Sanghoon; Robert, Aymeric

    2017-06-01

    We report experimental demonstration of capturing single-shot X-ray Free-electron Laser (FEL) beam profiles using gas fluorescence. The measurement was carried out at the Linac Coherent Light Source using 7 keV hard X-rays propagating through ambient air. The nitrogen fluorescence emitted upon the passage of the X-ray FEL beam were imaged using a highly sensitive optical setup, and there was sufficient optical yield that single-shot measurements were feasible. By taking two orthogonal and simultaneous images, the beam trajectory could be determined in a nearly non-invasive manner, and is best suited for photon energies in the soft X-ray regime, where such a diagnostic capability has been largely unavailable previously. The integrated intensity of the images could also serve as a non-invasive intensity monitor, complementary to current implementations of gas- and solidbased monitors. High repetition-rate Free-electron Lasers can greatly benefit from such a new diagnostic tool for eliminating potential thermal damages.

  1. Characterisation of microfocused beam for synchrotron powder diffraction using a new X-ray camera

    International Nuclear Information System (INIS)

    Thomas, C; Potter, J; Tang, C C; Lennie, A R

    2012-01-01

    The powder diffraction beamline I11, Diamond Light Source, is being continually upgraded as requirements of the user community evolve. Intensities of X-rays from the I11 in-vacuum electron undulator in the 3 GeV synchrotron fall off at higher energies. By focusing higher energy X-rays, we can overcome flux limitations, and open up new diffraction experiments. Here, we describe characterisation of microfocusing using compound refractive lenses (CRL). For a relatively modest outlay, we have developed an experimental setup and a novel X-ray camera with good sensitivity and a resolution specification suitable for characterising these focusing optics. We show that vertical oscillations in the focused beam compromise resolution of the source imaged by the CRL. Nevertheless, we have measured CRL focusing properties, and demonstrate the use of energy scanning to determine lens alignment. Real benefits of the intensity gain are illustrated.

  2. Experimental characterization of X-ray transverse coherence in the presence of beam transport optics

    DEFF Research Database (Denmark)

    Chubar, O.; Fluerasu, A.; Chu, Y.S.

    2013-01-01

    A simple Boron fiber based interference scheme [1] and other similar schemes are currently routinely used for X-ray coherence estimation at 3rd generation synchrotron radiation sources. If such a scheme is applied after a perfect monochromator and without any focusing / transport optics...... in the optical path, the interpretation of the measured interference pattern is relatively straightforward and can be done in terms of the basic parameters of the source [2]. However, if the interference scheme is used after some focusing optics, e.g. close to the X-ray beam waist, the visibility of fringes can...... propagation based simulations show, in particular, that new generation 1D Beryllium Compound Refractive Lenses [3, 4] do not reduce the X-ray transverse coherence in any significant manner....

  3. Device for the collimation of a high-energy beam, in particular a X-ray beam

    International Nuclear Information System (INIS)

    Peyser, L.F.

    1976-01-01

    The design of apertures made of radiation-absorbing material intended for limiting an aperture for a radiation beam of high energy, in particular an X-ray beam is claimed. The apertures are shaped as trapezoids, are held movably, and are adjustable by means of a control device. (UWI) [de

  4. Long-term stability of beam quality and output of conventional X-ray units.

    Science.gov (United States)

    Fukuda, Atsushi; Matsubara, Kosuke; Miyati, Tosiaki

    2015-01-01

    Conventional diagnostic X-ray units are used for radiographic imaging in many countries. For obtaining entrance surface doses, a numerical dose determination method has been applied in Japan. Although this technique is effective, it has to account for errors, particularly fluctuations, due to the beam quality and output of X-ray tubes. As a part of our quality control procedures, we recorded the entrance surface air kerma, tube voltage, and half-value layer measurements made for four diagnostic X-ray tubes over a 103-week period. The entrance surface air kerma for one of the four X-ray tubes had increased significantly by 11.4 % over 1 year from its initial setting, whereas the tube voltages and half-value layers did not deviate significantly from their initial values. Medical physicists and radiological technologists should be aware of this fluctuation for diagnostic X-ray tubes and take it into consideration when calculating the entrance surface air kerma.

  5. Spectrometry of X-ray beams using Cadmium and Zinc Teluride detector

    International Nuclear Information System (INIS)

    Becker, Paulo Henriques Bastos

    1997-06-01

    Determination of X-ray spectra to be utilized for medical diagnostics is a complementary process to the development of procedures to be applied to the quality control of radiodiagnostics X-ray equipment. Until some years ago, that was only possible using Germanium or Silicon detectors. Both have an excellent resolution in this energy range, but present also some restrictions as there are high costs and the necessity of operating them at temperature of liquid Nitrogen, which is not always available at the measurement's place. Room temperature detectors like Cadmium Telluride and Mercury Iodine don't have these restrictions. They, however, have a lower resolution and incomplete collection of the charges produced by their interaction with radiation. With technological advance of crystal growth in general and new techniques like cooling the crystal with a Peltier cell and rise time discrimination circuits, today Cadmium Telluride detectors show a resolution very close to that from Germanium detectors. This work relates to the routine use of Cadmium and Zinc Telluride detectors for measuring X-ray spectra in loco of diagnostic X-ray units. It characterizes the properties of a commercially available detector and offers a model for stripping the measured pulse height distribution. It was also developed a collimator to allow the direct measurement of the beam. The model developed and the constructed set-up were applied to two X-ray tubes and the achieved spectra compared with some spectra available from the literature. (author)

  6. Electron beam-based sources of ultrashort x-ray pulses.

    Energy Technology Data Exchange (ETDEWEB)

    Zholents, A.; Accelerator Systems Division (APS)

    2010-09-30

    A review of various methods for generation of ultrashort x-ray pulses using relativistic electron beam from conventional accelerators is presented. Both spontaneous and coherent emission of electrons is considered. The importance of the time-resolved studies of matter at picosecond (ps), femtosecond (fs), and atttosecond (as) time scales using x-rays has been widely recognized including by award of a Nobel Prize in 1999 [Zewa]. Extensive reviews of scientific drivers can be found in [BES1, BES2, BES3, Lawr, Whit]. Several laser-based techniques have been used to generate ultrashort x-ray pulses including laser-driven plasmas [Murn, Alte, Risc, Rose, Zamp], high-order harmonic generation [Schn, Rund, Wang, Arpi], and laser-driven anode sources [Ande]. In addition, ultrafast streak-camera detectors have been applied at synchrotron sources to achieve temporal resolution on the picosecond time scale [Wulf, Lind1]. In this paper, we focus on a different group of techniques that are based on the use of the relativistic electron beam produced in conventional accelerators. In the first part we review several techniques that utilize spontaneous emission of electrons and show how solitary sub-ps x-ray pulses can be obtained at existing storage ring based synchrotron light sources and linacs. In the second part we consider coherent emission of electrons in the free-electron lasers (FELs) and review several techniques for a generation of solitary sub-fs x-ray pulses. Remarkably, the x-ray pulses that can be obtained with the FELs are not only significantly shorter than the ones considered in Part 1, but also carry more photons per pulse by many orders of magnitude.

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

    Directory of Open Access Journals (Sweden)

    Surała Władysław

    2016-06-01

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

  8. Note: Grazing incidence small and wide angle x-ray scattering combined with imaging ellipsometry

    Energy Technology Data Exchange (ETDEWEB)

    Koerstgens, V.; Meier, R.; Ruderer, M. A.; Guo, S.; Chiang, H.-Y.; Mueller-Buschbaum, P. [Technische Universitaet Muenchen, Physik-Department, Lehrstuhl fuer Funktionelle Materialien, James-Franck-Str. 1, 85748 Garching (Germany); Perlich, J.; Roth, S. V.; Gehrke, R. [HASYLAB, DESY, Notkestr. 85, 22607, Hamburg (Germany)

    2012-07-15

    The combination of grazing incidence small angle x-ray scattering (GISAXS) and grazing incidence wide angle x-ray scattering (GIWAXS) with optical imaging ellipsometry is presented as an upgrade of the available measurement techniques at the wiggler beamline BW4 of the Hamburger Synchrotronstrahlungslabor. The instrument is introduced with the description of the alignment procedure to assure the measurement of imaging ellipsometry and GISAXS/GIWAXS on the same sample spot. To demonstrate the possibilities of the new instrument examples of morphological investigation on films made of poly(3-hexylthiophene) and [6,6]-phenyl-C{sub 61} butyric acid methyl ester as well as textured poly(9,9-dioctylfluorene-alt-benzo-thia-diazole) are shown.

  9. BEAM OPTIMIZATION STUDY FOR AN X-RAY FEL OSCILLATOR AT THE LCLS-II

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Weilun; Huang, S.; Liu, K.X.; Huang, Z; Ding, Y.; Maxwell, T.J.; Kim, K.-J.

    2016-06-01

    The 4 GeV LCLS-II superconducting linac with high repetition beam rate enables the possibility to drive an X-Ray FEL oscillator at harmonic frequencies *. Compared to the regular LCLS-II machine setup, the oscillator mode requires a much longer bunch length with a relatively lower current. Also a flat longitudinal phase space distribution is critical to maintain the FEL gain since the X-ray cavity has extremely narrow bandwidth. In this paper, we study the longitudinal phase space optimization including shaping the initial beam from the injector and optimizing the bunch compressor and dechirper parameters. We obtain a bunch with a flat energy chirp over 400 fs in the core part with current above 100 A. The optimization was based on LiTrack and Elegant simulations using LCLS-II beam parameters.

  10. Polychromatic X-ray Micro- and Nano-Beam Science and Instrumentation

    Science.gov (United States)

    Ice, G. E.; Larson, B. C.; Liu, W.; Barabash, R. I.; Specht, E. D.; Pang, J. W. L.; Budai, J. D.; Tischler, J. Z.; Khounsary, A.; Liu, C.; Macrander, A. T.; Assoufid, L.

    2007-01-01

    Polychromatic x-ray micro- and nano-beam diffraction is an emerging nondestructive tool for the study of local crystalline structure and defect distributions. Both long-standing fundamental materials science issues, and technologically important questions about specific materials systems can be uniquely addressed. Spatial resolution is determined by the beam size at the sample and by a knife-edge technique called differential aperture microscopy that decodes the origin of scattering from along the penetrating x-ray beam. First-generation instrumentation on station 34-ID-E at the Advanced Photon Source (APS) allows for nondestructive automated recovery of the three-dimensional (3D) local crystal phase and orientation. Also recovered are the local elastic-strain and the dislocation tensor distributions. New instrumentation now under development will further extend the applications of polychromatic microdiffraction and will revolutionize materials characterization.

  11. Polychromatic X-ray Micro- and Nano-Beam Science and Instrumentation

    International Nuclear Information System (INIS)

    Ice, G.E.; Larson, Ben C.; Liu, Wenjun; Barabash, Rozaliya; Specht, Eliot D; Pang, Judy; Budai, John D.; Tischler, Jonathan Zachary; Khounsary, Ali; Liu, Chian; Macrander, Albert T.; Assoufid, Lahsen

    2007-01-01

    Polychromatic x-ray micro- and nano-beam diffraction is an emerging nondestructive tool for the study of local crystalline structure and defect distributions. Both long-standing fundamental materials science issues, and technologically important questions about specific materials systems can be uniquely addressed. Spatial resolution is determined by the beam size at the sample and by a knife-edge technique called differential aperture microscopy that decodes the origin of scattering from along the penetrating x-ray beam. First-generation instrumentation on station 34-ID-E at the Advanced Photon Source (APS) allows for nondestructive automated recovery of the three-dimensional (3D) local crystal phase and orientation. Also recovered are the local elastic-strain and the dislocation tensor distributions. New instrumentation now under development will further extend the applications of polychromatic microdiffraction and will revolutionize materials characterization

  12. In situ surface/interface x-ray diffractometer for oxide molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J. H. [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA; Tung, I. C. [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA; Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, USA; Chang, S. -H. [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA; Bhattacharya, A. [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA; Fong, D. D. [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA; Freeland, J. W. [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA; Hong, Hawoong [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA

    2016-01-01

    In situ studies of oxide molecular beam epitaxy by synchrotron x-ray scattering has been made possible by upgrading an existing UHV/molecular beam epitaxy (MBE) six-circle diffractometer system. For oxide MBE growth, pure ozone delivery to the chamber has been made available, and several new deposition sources have been made available on a new 12 in. CF (ConFlat, a registered trademark of Varian, Inc.) flange. X-ray diffraction has been used as a major probe for film growth and structures for the system. In the original design, electron diffraction was intended for the secondary diagnostics available without the necessity of the x-ray and located at separate positions. Deposition of films was made possible at the two diagnostic positions. And, the aiming of the evaporation sources is fixed to the point between two locations. Ozone can be supplied through two separate nozzles for each location. Also two separate thickness monitors are installed. Additional features of the equipment are also presented together with the data taken during typical oxide film growth to illustrate the depth of information available via in situ x-ray techniques.

  13. In situ surface/interface x-ray diffractometer for oxide molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J. H.; Freeland, J. W.; Hong, Hawoong, E-mail: hhong@aps.anl.gov [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Tung, I. C. [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208 (United States); Chang, S.-H.; Bhattacharya, A.; Fong, D. D. [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

    2016-01-15

    In situ studies of oxide molecular beam epitaxy by synchrotron x-ray scattering has been made possible by upgrading an existing UHV/molecular beam epitaxy (MBE) six-circle diffractometer system. For oxide MBE growth, pure ozone delivery to the chamber has been made available, and several new deposition sources have been made available on a new 12 in. CF (ConFlat, a registered trademark of Varian, Inc.) flange. X-ray diffraction has been used as a major probe for film growth and structures for the system. In the original design, electron diffraction was intended for the secondary diagnostics available without the necessity of the x-ray and located at separate positions. Deposition of films was made possible at the two diagnostic positions. And, the aiming of the evaporation sources is fixed to the point between two locations. Ozone can be supplied through two separate nozzles for each location. Also two separate thickness monitors are installed. Additional features of the equipment are also presented together with the data taken during typical oxide film growth to illustrate the depth of information available via in situ x-ray techniques.

  14. LabVIEW control software for scanning micro-beam X-ray fluorescence spectrometer.

    Science.gov (United States)

    Wrobel, Pawel; Czyzycki, Mateusz; Furman, Leszek; Kolasinski, Krzysztof; Lankosz, Marek; Mrenca, Alina; Samek, Lucyna; Wegrzynek, Dariusz

    2012-05-15

    Confocal micro-beam X-ray fluorescence microscope was constructed. The system was assembled from commercially available components - a low power X-ray tube source, polycapillary X-ray optics and silicon drift detector - controlled by an in-house developed LabVIEW software. A video camera coupled to optical microscope was utilized to display the area excited by X-ray beam. The camera image calibration and scan area definition software were also based entirely on LabVIEW code. Presently, the main area of application of the newly constructed spectrometer is 2-dimensional mapping of element distribution in environmental, biological and geological samples with micrometer spatial resolution. The hardware and the developed software can already handle volumetric 3-D confocal scans. In this work, a front panel graphical user interface as well as communication protocols between hardware components were described. Two applications of the spectrometer, to homogeneity testing of titanium layers and to imaging of various types of grains in air particulate matter collected on membrane filters, were presented. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. Study of energy dependence of a extrapolation chamber in low energy X-rays beams

    International Nuclear Information System (INIS)

    Bastos, Fernanda M.; Silva, Teogenes A. da

    2014-01-01

    This work was with the main objective to study the energy dependence of extrapolation chamber in low energy X-rays to determine the value of the uncertainty associated with the variation of the incident radiation energy in the measures in which it is used. For studying the dependence of energy, were conducted comparative ionization current measurements between the extrapolation chamber and two ionization chambers: a chamber mammography, RC6M model, Radcal with energy dependence less than 5% and a 2575 model radioprotection chamber NE Technology; both chambers have very thin windows, allowing its application in low power beams. Measurements were made at four different depths of 1.0 to 4.0 mm extrapolation chamber, 1.0 mm interval, for each reference radiation. The study showed that there is a variable energy dependence on the volume of the extrapolation chamber. In other analysis, it is concluded that the energy dependence of extrapolation chamber becomes smaller when using the slope of the ionization current versus depth for the different radiation reference; this shows that the extrapolation technique, used for the absorbed dose calculation, reduces the uncertainty associated with the influence of the response variation with energy radiation

  16. Fluctuations on the X-ray intensity beam using a portable X-ray probe based on {sup 6}LiI(Eu) crystal

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Geraldo P.; Oliveira, Arno H. [Universidade Federal de Minas Gerais (PCTN/UFMG), Belo Horizonte, MG (Brazil). Programa de Pos-Graduacao em Ciencias e Tecnicas Nucleares; Carneiro, Andre C.; Carneiro, Clemente J.G.; Milian, Felix M.; Velasco, Fermin G., E-mail: fermin@uesc.b [Universidade Estadual de Santa Cruz (CPqCTR/UESC), Ilheus, BA (Brazil). Centro de Pesquisa em Ciencias e Tecnologias das Radiacoes

    2011-07-01

    X-rays are produced by accelerating electrons with a high voltage and allowing them to collide with a metal target. This high voltage presents fluctuations that define peak, minimum, and average voltages. Different voltages are applied to the X-ray tube depending on the radiographic applications. A rectifier circuit converts the alternating high voltage to unidirectional high voltage to accelerate electrons in this tube. The fluctuations on the energy in the electron beam depend on the mode of rectification. Both energy of the electrons and X rays intensity fluctuates. A portable probe built with a {sup 6}LiI(Eu) detector coupled to a 10 m light guide and a Hamamatsu photon counting head H9319 was used to measuring X ray intensities. This system is designed to collect up to 10000 counts in intervals of 10 ms to 1 s. Counts were accumulated in time intervals of 10 ms during 10 s. The system starts the count before activating the X-ray apparatus, which is on during a time interval of 100ms. During this period, counts may overflow in consequence high voltage was adjusted to be 40kV, in order to avoid such a problem. For each of these points dose was measured using an ionization chamber. The objectives of this work are to study fluctuations on the X-ray beam and to calibrate the portable probe for measuring radiation doses. Counting rates measured for each 10 ms presented strong variations due to high voltages fluctuations. Both dose and counting rate when correlated with distances between source and detector followed the inverse square law and presented values of R2 near of unit. A calibration curve of the portable system for dose measurements showed also R2 value near of unity. (author)

  17. X-ray beam monitor made by thin-film CVD single-crystal diamond.

    Science.gov (United States)

    Marinelli, Marco; Milani, E; Prestopino, G; Verona, C; Verona-Rinati, G; Angelone, M; Pillon, M; Kachkanov, V; Tartoni, N; Benetti, M; Cannatà, D; Di Pietrantonio, F

    2012-11-01

    A novel beam position monitor, operated at zero bias voltage, based on high-quality chemical-vapor-deposition single-crystal Schottky diamond for use under intense synchrotron X-ray beams was fabricated and tested. The total thickness of the diamond thin-film beam monitor is about 60 µm. The diamond beam monitor was inserted in the B16 beamline of the Diamond Light Source synchrotron in Harwell (UK). The device was characterized under monochromatic high-flux X-ray beams from 6 to 20 keV and a micro-focused 10 keV beam with a spot size of approximately 2 µm × 3 µm square. Time response, linearity and position sensitivity were investigated. Device response uniformity was measured by a raster scan of the diamond surface with the micro-focused beam. Transmissivity and spectral responsivity versus beam energy were also measured, showing excellent performance of the new thin-film single-crystal diamond beam monitor.

  18. Cone Beam X-Ray Luminescence Tomography Imaging Based on KA-FEM Method for Small Animals.

    Science.gov (United States)

    Chen, Dongmei; Meng, Fanzhen; Zhao, Fengjun; Xu, Cao

    2016-01-01

    Cone beam X-ray luminescence tomography can realize fast X-ray luminescence tomography imaging with relatively low scanning time compared with narrow beam X-ray luminescence tomography. However, cone beam X-ray luminescence tomography suffers from an ill-posed reconstruction problem. First, the feasibility of experiments with different penetration and multispectra in small animal has been tested using nanophosphor material. Then, the hybrid reconstruction algorithm with KA-FEM method has been applied in cone beam X-ray luminescence tomography for small animals to overcome the ill-posed reconstruction problem, whose advantage and property have been demonstrated in fluorescence tomography imaging. The in vivo mouse experiment proved the feasibility of the proposed method.

  19. On diamond windows for high power synchrotron x-ray beams

    International Nuclear Information System (INIS)

    Khounsary, A.M.; Kuzay, T.M.

    1992-01-01

    X-ray windows are often used on the front end of synchrotron beamlines to isolate the ultra high vacuum of the storage ring from the downstream environment. The windows are usually made of low atomic number materials, such as beryllium, for maximum x-ray transmission, and they must survive and remain vacuum tight during repeated thermal cycles. The intense x-ray beams generated by the wigglers and undulators at high energy storage rings can deposit substantial amounts of localized heat in the (actively cooled) windows leading to high temperatures, and vacuum or structural failure. Thermal filters upstream of the windows can be used to reduce the radiation absorbed in the windows. This solution has limitations, however, since a small amount of filtering may still leave an unacceptable amount of heat to be absorbed in the windows, while substantial filtering will absorb a large amount of the useful photons. Recent advances in chemical vapor deposition (CVD) technology has made available thin, free-standing polycrystalline diamond films that can be used as the window material on high heat load synchrotron x-ray beamlines. Diamond windows have many advantages that stem from the exceptional thermal, structural, and physical properties of diamond. Numerical simulation indicates that diamond windows offer an attractive alternative to beryllium windows for use on the third generation x-ray synchrotron radiation beamlines. Utilization, design, and fabrication aspects of diamond windows for high heat load x-ray beamlines are discussed, and analytical results are presented to provide a basis for design and testing of such windows

  20. Studies on polymer thin film structure by X-ray and neutron reflectivity and grazing incidence small angle scattering

    International Nuclear Information System (INIS)

    Ogawa, Hiroki; Kanaya, Toshiji

    2011-01-01

    We have reviewed structure studies of polymer thin films using synchrotron radiation X-ray and neutron reflectivity as well as recently developed grazing incidence small-angle X-ray and neutron scattering, including studies on polymer thin films with embedded ordered nanometer cells, distribution of glass transition temperature Tg in thin polystyrene films, and dewetting process of polymer blend thin films. (author)

  1. Comparison of neutron and high-energy X-ray dual-beam radiography for air cargo inspection

    International Nuclear Information System (INIS)

    Liu, Y.; Sowerby, B.D.; Tickner, J.R.

    2008-01-01

    Dual-beam radiography techniques utilising various combinations of high-energy X-rays and neutrons are attractive for screening bulk cargo for contraband such as narcotics and explosives. Dual-beam radiography is an important enhancement to conventional single-beam X-ray radiography systems in that it provides additional information on the composition of the object being imaged. By comparing the attenuations of transmitted dual high-energy beams, it is possible to build a 2D image, colour coded to indicate material. Only high-energy X-rays, gamma-rays and neutrons have the required penetration to screen cargo containers. This paper reviews recent developments and applications of dual-beam radiography for air cargo inspection. These developments include dual high-energy X-ray techniques as well as fast neutron and gamma-ray (or X-ray) radiography systems. High-energy X-ray systems have the advantage of generally better penetration than neutron systems, depending on the material being interrogated. However, neutron systems have the advantage of much better sensitivity to material composition compared to dual high-energy X-ray techniques. In particular, fast neutron radiography offers the potential to discriminate between various classes of organic material, unlike dual energy X-ray techniques that realistically only offer the ability to discriminate between organic and metal objects

  2. National Synchrotron Light Source users manual: Guide to the VUV and x-ray beam lines

    International Nuclear Information System (INIS)

    Gmuer, N.F.; White-DePace, S.M.

    1987-08-01

    The success of the National Synchrotron Light Source in the years to come will be based, in large part, on the size of the users community and the diversity of the scientific disciplines represented by these users. In order to promote this philosophy, this National Synchrotron Light Source (NSLS) Users Manual: Guide to the VUV and X-Ray Beam Lines, has been published. This manual serves a number of purposes. In an effort to attract new research, it will present to the scientific community-at-large the current and projected architecture and capabilities of the various VUV and x-ray beam lines and storage rings. We anticipate that this publication will be updated periodically in order to keep pace with the constant changes at the NSLS

  3. First combined total reflection X-ray fluorescence and grazing incidence X-ray absorption spectroscopy characterization of aeolian dust archived in Antarctica and Alpine deep ice cores

    Energy Technology Data Exchange (ETDEWEB)

    Cibin, G. [Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxon OX110DE (United Kingdom); IMONT/EIM, Ente Italiano della Montagna, P.za dei Caprettari 70, 00176 Roma (Italy); Universita' degli Studi di Roma Tre, Dipartimento di Scienze Geologiche, L.go S. Leonardo Murialdo 1, 00146 Roma (Italy)], E-mail: giannantonio.cibin@diamond.ac.uk; Marcelli, A. [INFN - Laboratori Nazionali di Frascati, P.O. Box 13, 00044 Frascati (Roma) (Italy); Maggi, V. [Universita degli Studi di Milano-Bicocca, Dipartimento di Scienze dell' Ambiente e del Territorio, Piazza della Scienza 1, 20126 Milano (Italy); Sala, M. [Universita degli Studi di Milano-Bicocca, Dipartimento di Scienze dell' Ambiente e del Territorio, Piazza della Scienza 1, 20126 Milano (Italy); Universita degli Studi di Milano, Dipartimento di Scienze della Terra ' A. Desio' , Sez. Mineralogia, Via Mangiagalli 34, 20133 Milano (Italy); Marino, F.; Delmonte, B. [Universita degli Studi di Milano-Bicocca, Dipartimento di Scienze dell' Ambiente e del Territorio, Piazza della Scienza 1, 20126 Milano (Italy); Albani, S. [Universita degli Studi di Milano-Bicocca, Dipartimento di Scienze dell' Ambiente e del Territorio, Piazza della Scienza 1, 20126 Milano (Italy); Universita degli Studi di Siena, Dottorato in Scienze Polari, via Laterina 8, 53100 Siena (Italy); Pignotti, S. [IMONT/EIM, Ente Italiano della Montagna, P.za dei Caprettari 70, 00176 Roma (Italy)

    2008-12-15

    Aeolian mineral dust archived in polar and mid latitude ice cores represents a precious proxy for assessing environmental and climatic variations at different timescales. In this respect, the identification of dust mineralogy plays a key role. In this work we performed the first preliminary X-ray absorption spectroscopy (XAS) experiments on mineral dust particles extracted from Antarctic and from Alpine firn cores using grazing incidence geometry at the Fe K-edge. A dedicated high vacuum experimental chamber was set up for normal-incidence and total-reflection X-Ray Fluorescence and Absorption Spectroscopy analyses on minor amounts of mineral materials at the Stanford Synchrotron Radiation Laboratory. Results show that this experimental technique and protocol allows recognizing iron inclusion mineral fraction on insoluble dust in the 1-10 {mu}g range.

  4. Optimization of Grazing Incidence Optics for Wide-Field X-Ray Survey Imaging

    Science.gov (United States)

    Roming, P. W. A.; Burrows, D. N.; Garmire, G. P.; Roush, W. B.

    1999-12-01

    Optimization of wide-field X-ray optics could greatly enhance X-ray surveys. Discussions of optimizing wide-field X-ray optics, with field-of-views less-than 1.1 degree-squared, have been made previously in the literature. However, very little has been published about the optimizing of wide-field X-ray optics with larger fields-of-view. We have been working on the design of a wide-field (3.1 degree-squared field-of-view), short focal length (190.5 cm), grazing incidence mirror shell set, with a desired rms image spot size of 15 arcsec. The baseline design incorporates Wolter I type mirror shells with polynomial perturbations applied to the grazing incidence surface. By optimizing the polynomial, the rms image spot size can be minimized for a large range of grazing angles. The overall minimization technique is to efficiently optimize the polynomial coefficients that directly influence the angular resolution, without stepping through the entire multidimensional coefficient space. The multidimensional minimization techniques that have been investigated include: the downhill simplex method; the coupling of genetic algorithms with full and fractional, including Plackett-Burman, factorial designs; and the coupling of genetic algorithms with Box-Behnken and central composite response surface designs. We have also examined the use of neural networks, coupled with genetic algorithms, as a method of multidimensional minimization. Investigations of backpropagation, probabilistic (PNN), general regression (GRNN), and group method of data handling (GMDH) neural networks have been made. We report our findings to date. This research is funded by NASA grant #NAG5-5093.

  5. Time and space domain separation of pulsed X-ray beams diffracted from vibrating crystals

    Energy Technology Data Exchange (ETDEWEB)

    Nosik, V. L., E-mail: v-nosik@yandex.ru, E-mail: nosik@ns.crys.ras.ru [Russian Academy of Sciences, Shubnikov Institute of Crystallography, Federal Scientific Research Centre “Crystallography and Photonics,” (Russian Federation)

    2016-11-15

    It is known that a set of additional reflections (satellites) may arise on rocking curves in the case of X-ray diffraction in the Bragg geometry from crystals where high-frequency ultrasonic vibrations are excited. It is shown that, under certain conditions, the pulse wave fields of the satellites and main reflection may be intersected in space (playing the role of pump and probe beams) and in time (forming interference superlattices).

  6. Functional characterization of planar sensors with active edges using laser and X-ray beam scans

    International Nuclear Information System (INIS)

    Povoli, M.; Bagolini, A.; Boscardin, M.; Dalla Betta, G.-F.; Giacomini, G.; Hasi, J.; Oh, A.; Zorzi, N.

    2013-01-01

    We report on the functional characterization of planar sensors with active edges fabricated at Fondazione Bruno Kessler (FBK), Trento, Italy. The measurements here reported were performed by means of laser and X-ray beam scans mainly focusing on the signal efficiency of the edge region of the devices. Results are very encouraging and show very good sensitivity up to few microns away from the device physical edge

  7. Functional characterization of planar sensors with active edges using laser and X-ray beam scans

    Energy Technology Data Exchange (ETDEWEB)

    Povoli, M., E-mail: povoli@disi.unitn.it [Dipartimento di Ingegneria e Scienza dell' Informazione, Università di Trento, Via Sommarive, 14, I-38123 Povo di Trento (Italy); INFN, Sezione di Padova (Gruppo Collegato di Trento),Via Sommarive, 14, I-38123 Povo di Trento (Italy); Bagolini, A.; Boscardin, M. [Fondazione Bruno Kessler, Centro per i Materiali e i Microsistemi (FBK-CMM), Via Sommarive, 18, I-38123 Povo di Trento (Italy); Dalla Betta, G.-F. [Dipartimento di Ingegneria e Scienza dell' Informazione, Università di Trento, Via Sommarive, 14, I-38123 Povo di Trento (Italy); INFN, Sezione di Padova (Gruppo Collegato di Trento),Via Sommarive, 14, I-38123 Povo di Trento (Italy); Giacomini, G. [Fondazione Bruno Kessler, Centro per i Materiali e i Microsistemi (FBK-CMM), Via Sommarive, 18, I-38123 Povo di Trento (Italy); Hasi, J. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025-7015 (United States); Oh, A. [The University of Manchester, Oxford Road, Manchester M13 9PL (United Kingdom); Zorzi, N. [Fondazione Bruno Kessler, Centro per i Materiali e i Microsistemi (FBK-CMM), Via Sommarive, 18, I-38123 Povo di Trento (Italy)

    2013-08-01

    We report on the functional characterization of planar sensors with active edges fabricated at Fondazione Bruno Kessler (FBK), Trento, Italy. The measurements here reported were performed by means of laser and X-ray beam scans mainly focusing on the signal efficiency of the edge region of the devices. Results are very encouraging and show very good sensitivity up to few microns away from the device physical edge.

  8. Impact of large x-ray beam collimation on image quality

    Science.gov (United States)

    Racine, Damien; Ba, Alexandre; Ott, Julien G.; Bochud, François O.; Verdun, Francis R.

    2016-03-01

    Large X-ray beam collimation in computed tomography (CT) opens the way to new image acquisition techniques and improves patient management for several clinical indications. The systems that offer large X-ray beam collimation enable, in particular, a whole region of interest to be investigated with an excellent temporal resolution. However, one of the potential drawbacks of this option might be a noticeable difference in image quality along the z-axis when compared with the standard helical acquisition mode using more restricted X-ray beam collimations. The aim of this project is to investigate the impact of the use of large X-ray beam collimation and new iterative reconstruction on noise properties, spatial resolution and low contrast detectability (LCD). An anthropomorphic phantom and a custom made phantom were scanned on a GE Revolution CT. The images were reconstructed respectively with ASIR-V at 0% and 50%. Noise power spectra, to evaluate the noise properties, and Target Transfer Functions, to evaluate the spatial resolution, were computed. Then, a Channelized Hotelling Observer with Gabor and Dense Difference of Gaussian channels was used to evaluate the LCD using the Percentage correct as a figure of merit. Noticeable differences of 3D noise power spectra and MTF have been recorded; however no significant difference appeared when dealing with the LCD criteria. As expected the use of iterative reconstruction, for a given CTDIvol level, allowed a significant gain in LCD in comparison to ASIR-V 0%. In addition, the outcomes of the NPS and TTF metrics led to results that would contradict the outcomes of CHO model observers if used for a NPWE model observer (Non- Prewhitening With Eye filter). The unit investigated provides major advantages for cardiac diagnosis without impairing the image quality level of standard chest or abdominal acquisitions.

  9. Dose reduction by x-ray beam filtration in screen-film radiography

    International Nuclear Information System (INIS)

    Koedooder, C.

    1986-01-01

    This thesis describes experimental and theoretical aspects of dose reduction by x-ray beam filtration in screen-film radiography. The thesis deals mainly with dose reduction under the constraint of constant image quality; an analytical approach is chosen. Therefore, part of the thesis deals with the development of an algorithm to calculate patient dose and exposure for different filter materials and different tube load conditions, under the constraint of constant contrast and constant optical density. (Auth.)

  10. Parallel beam microradiography of dental hard tissue using synchrotron radiation and X-ray image magnification

    International Nuclear Information System (INIS)

    Takagi, S.; Chow, L.C.; Brown, W.E.; Dobbyn, R.C.; Kuriyama, M.

    1984-01-01

    A novel technique utilizing a highly parallel beam of monochromatic synchrotron radiation combined with X-ray image magnification has been used to obtain microradiographs of caries lesions in relatively thick tooth sections. Preliminary results reveal structural features not previously reported. This technique holds the promise of allowing one to follow the structural changes accompanying the formation, destruction and chemical repair of mineralized tissue in real time. (orig.)

  11. Comparison between different kinds of additional filtration in standards X-ray beams, mammography level

    Energy Technology Data Exchange (ETDEWEB)

    Correa, Eduardo de Lima; Vivolo, Vitor; Potiens, Maria da Penha Albuquerque, E-mail: edu1905@gmail.co, E-mail: vivolo@ipen.b, E-mail: mppalbu@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2009-07-01

    In this work has been made a comparison between different materials used as filtration in standards X-ray beams, mammography level. For this, was analyzed the parameters that give the radiation spectrum, such as tube voltage and current, additional filtration and half-value layer. For the additional filtration have been used Molybdenum (Mo) and Aluminum (Al), in an X-ray system with a tube of Tungsten (W) target. Because of the difficulty to establish mammography qualities in a standard X-ray system, given the limitations created by the IEC 61267, it is necessary to create a procedure based on different reports, presented by different organizations, such as the International Atomic Energy Agency and the Physikalisch-Technischen Bundesanstalt (PTB). The last one presents some results obtained with an X-ray tube with an anode of W. The IEC 61267 presents a fixed filtration of 0.03 mm of Mo, for a tube with an anode of this same material. In this work was determined an additional filtration of Mo that could simulate the specter emitted by an anode of this material, using the HVL as parameter. For the filtration of Al, it was followed the data presented by the PTB. The additional filtration has been determined using the same parameter. (author)

  12. On symmetric X-ray beam splitting with high efficiency by use of reflection gratings with rectangular profile in the extreme off-plane configuration.

    Science.gov (United States)

    Jark, Werner; Eichert, Diane

    2015-08-24

    In order to be reflected or diffracted off a surface structure soft X-rays and hard X-rays need to impinge at grazing angles of incidence onto the surface. In case of a reflection grating of highly symmetric structure with rectangular groove profile these grooves can be oriented parallel to the beam trajectory. In such a symmetric situation the distribution of the diffracted intensity with respect to the plane of incidence is then expected to be symmetric. This is indeed observed with symmetrically oriented diffraction peaks. It can be predicted that for appropriate structure parameters the intensity can be contained mostly in two symmetrically oriented diffraction peaks. This will also be the case for hard X-rays. The diffraction efficiency will be particularly high, when the angle of grazing incidence is chosen in the total reflection regime below the critical angle of the grating coating. These predictions were experimentally verified in this work for hard X-rays with photon energies between 4 keV and 12.4 keV. In the experiment of the order of 30% of the incident intensity was diffracted into the two first orders. This is to be compared to reflectivities of the order of 50% measured at the same coating in an unruled area of the substrate. Consequently the relative structural diffraction efficiency for each first order was about 30%, while ideally it could have been 40%. The presented grating structure will thus be a rather efficient amplitude beam splitter for hard X-rays, e.g. in the coherent beam from a free electron laser. In addition such object could then be used as the first component in Michelson interferometers for the beam characterisation or for introducing a time delay between two coherent beams.

  13. Advanced simulations of x-ray beam propagation through CRL transfocators using ray-tracing and wavefront propagation methods

    DEFF Research Database (Denmark)

    Baltser, Jana; Bergbäck Knudsen, Erik; Vickery, Anette

    2011-01-01

    of X-ray beamline designs for particular user experiments. In this work we used the newly developed McXtrace ray-tracing package and the SRW wave-optics code to simulate the beam propagation of X-ray undulator radiation through such a "transfocator" as implemented at ID- 11 at ESRF. By applying two...

  14. Study of the grazing-incidence X-ray scattering of strongly disturbed fractal surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Roshchin, B. S., E-mail: ross@crys.ras.ru; Chukhovsky, F. N.; Pavlyuk, M. D.; Opolchentsev, A. M.; Asadchikov, V. E. [Russian Academy of Sciences, Shubnikov Institute of Crystallography, Federal Research Centre “Crystallography and Photonics” (Russian Federation)

    2017-03-15

    The applicability of different approaches to the description of hard X-ray scattering from rough surfaces is generally limited by a maximum surface roughness height of no more than 1 nm. Meanwhile, this value is several times larger for the surfaces of different materials subjected to treatment, especially in the initial treatment stages. To control the roughness parameters in all stages of surface treatment, a new approach has been developed, which is based on a series expansion of wavefield over the plane eigenstate-function waves describing the small-angle scattering of incident X-rays in terms of plane q-waves propagating through the interface between two media with a random function of relief heights. To determine the amplitudes of reflected and transmitted plane q-waves, a system of two linked integral equations was derived. The solutions to these equations correspond (in zero order) to the well-known Fresnel expressions for a smooth plane interface. Based on these solutions, a statistical fractal model of an isotropic rough interface is built in terms of root-mean-square roughness σ, two-point correlation length l, and fractal surface index h. The model is used to interpret X-ray scattering data for polished surfaces of single-crystal cadmium telluride samples.

  15. A method for measuring the time structure of synchrotron x-ray beams

    International Nuclear Information System (INIS)

    Moses, W.W.; Derenzo, S.E.

    1989-08-01

    We describe a method employing a plastic scintillator coupled to a fast photomultiplier tube to generate a timing pulse from the x-ray bursts emitted from a synchrotron radiation source. This technique is useful for performing synchrotron experiments where detailed knowledge of the timing distribution is necessary, such as time resolved spectroscopy or fluorescence lifetime experiments. By digitizing the time difference between the timing signal generated on one beam crossing with the timing signal generated on the next beam crossing, the time structure of a synchrotron beam can be analyzed. Using this technique, we have investigated the single bunch time structure at the National Synchrotron Light Source (NSLS) during pilot runs in January, 1989, and found that the majority of the beam (96%) is contained in one rf bucket, while the remainder of the beam (4%) is contained in satellite rf buckets preceeding and following the main rf bucket by 19 ns. 1 ref., 4 figs

  16. Heat transfer issues in high-heat-load synchrotron x-ray beams

    International Nuclear Information System (INIS)

    Khounsary, A.M.; Mills, D.M.

    1994-09-01

    In this paper, a short description of the synchrotron radiation x-ray sources and the associated power loads is given, followed by a brief description of typical synchrotron components and their heat load. It is emphasized that the design goals for most of these components is to limit (a) temperature, (b) stresses, or (c) strains in the system. Each design calls for a different geometry, material selection, and cooling scheme. Cooling schemes that have been utilized so far are primarily single phase and include simple macrochannel cooling, microchannel cooling, contact cooling, pin-post cooling, porous-flow cooling, jet cooling, etc. Water, liquid metals, and various cryogenic coolants have been used. Because the trend in x-ray beam development is towards brighter (i.e., more powerful) beams and assuming that no radical changes in the design of x-ray generating machines occurs in the next few years, it is fair to state that the utilization of various effective cooling schemes and, in particular, two-phase flow (e.g., subcooled boiling) warrants further investigation. This, however, requires a thorough examination of stability and reliability of two-phase flows for high-heat-flux components operating in ultrahigh vacuum with stringent reliability requirements

  17. X-ray beam penetration in TXRF measurement of polycrystalline and amorphous surfaces

    International Nuclear Information System (INIS)

    Ghatak-Roy, A.R.; Hossain, T.Z.

    2000-01-01

    For TXRF measurement on single crystal silicon surface, it is generally agreed that the x-ray beam penetration is of the order of a few hundred Angstroms from the surface. However, for polycrystalline and amorphous surfaces - frequently used in semiconductor manufacturing there are evidences that x-rays penetrate much deeper revealing underlying layers. The evidences come from various measurements done with films such as silicon dioxide, silicon nitride and metal films such as aluminum, titanium and cobalt. A systematic study was carried out to help understand the issue further. Four sets of samples (on 8 inch wafers) were prepared to create layers buried under various deposited metal and non-metal layers. The metal layers created were aluminum, titanium and cobalt and the non-metal layers were silicon dioxide and silicon nitride. These samples were analyzed by TXRF under various angles and energies and the data were analyzed for signals from various buried layers along with their angular dependence. The results indicated deep penetration of x-ray beams. The samples were further analyzed by SIMS (Secondary Ion Mass Spectrometry) and some of them by ICP-MS (Inductively Coupled Plasma - Mass Spectrometry) to obtain information about their depth profiles. This was done in order to rule out the possibility of intermixing of layers during deposition. (author)

  18. X-ray micro-beam characterization of a small pixel spectroscopic CdTe detector

    Science.gov (United States)

    Veale, M. C.; Bell, S. J.; Seller, P.; Wilson, M. D.; Kachkanov, V.

    2012-07-01

    A small pixel, spectroscopic, CdTe detector has been developed at the Rutherford Appleton Laboratory (RAL) for X-ray imaging applications. The detector consists of 80 × 80 pixels on a 250 μm pitch with 50 μm inter-pixel spacing. Measurements with an 241Am γ-source demonstrated that 96% of all pixels have a FWHM of better than 1 keV while the majority of the remaining pixels have FWHM of less than 4 keV. Using the Diamond Light Source synchrotron, a 10 μm collimated beam of monochromatic 20 keV X-rays has been used to map the spatial variation in the detector response and the effects of charge sharing corrections on detector efficiency and resolution. The mapping measurements revealed the presence of inclusions in the detector and quantified their effect on the spectroscopic resolution of pixels.

  19. X-ray beam transfer between hollow fibers for long-distance transport

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Yoshihito, E-mail: tanaka@sci.u-hyogo.ac.jp; Matsushita, Ryuki; Shiraishi, Ryutaro; Hasegawa, Takayuki; Ishikawa, Kiyoshi [Graduate School of Material Science, University of Hyogo, 3-2-1 Kouto, Kamigori-cho, Sayo-gun, Hyogo 678-1297 (Japan); Sawada, Kei; Kohmura, Yoshiki [RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Takahashi, Isao [Department of Physics, School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337 Japan (Japan)

    2016-07-27

    Fiber optics for controlling the x-ray beam trajectory has been examined at the synchrotron facility of SPring-8. Up to now, we have achieved beam deflection by several tens of milli-radian and axis shift of around 75 mm with a 1.5 m-long flexible hollow glass capillary. The achievable beam deflecting angle, axis shift, and timing delay are, in principle, proportional to the length, the square of length and the cube of length, respectively. Thus, for further applications, requiring larger beam shift and pulse delay, longer fibers are indispensable. In order to achieve long-distance transport using the fiber, we thus examined the connection transferring x-rays between fibers in an experimental hutch. The acceptance angle at the input end and the throughput efficiency of the second fiber is consistent with the consideration of the output beam divergence of the first fiber. The enhancement of the transfer efficiency is also discussed for the cases of a closer joint and the use of a refractive lens as a coupler.

  20. DOE/DMS workshop on future synchrotron VUV and x-ray beam Lines

    International Nuclear Information System (INIS)

    Green, P.H.

    1992-03-01

    This document contains an overview of the participating DOE Laboratory beam line interests and the projected science to be addressed on these beam lines, both at new and existing synchrotron facilities. The scientific programs associated with present and planned synchrotron research by DOE Laboratories are discussed in chapters titled ''VUV and Soft X-Ray Research'' and ''Hard X-Ray Research.'' This research encompasses a broad range of the nation's scientific and technical research needs from fundamental to applied, in areas including environmental, biological, and physical sciences; new materials; and energy-related technologies. The projected cost of this proposed construction has been provided in tabular form using a uniform format so that anticipated DOE and outside funding agency contributions for construction and for research and development can be determined. The cost figures are, of course, subject to uncertainties of detailed design requirements and the availability of facility-designed generic components and outside vendors. The report also contains a compendium (as submitted by the beam line proposers) of the design capabilities, the anticipated costs, and the scientific programs of projected beam line construction at the four synchrotron facilities. A summary of the projected cost of these beam lines to be requested of DOE is compiled

  1. Metal Artifact Reduction for Polychromatic X-ray CT Based on a Beam-Hardening Corrector.

    Science.gov (United States)

    Park, Hyoung Suk; Hwang, Dosik; Seo, Jin Keun

    2016-02-01

    This paper proposes a new method to correct beam hardening artifacts caused by the presence of metal in polychromatic X-ray computed tomography (CT) without degrading the intact anatomical images. Metal artifacts due to beam-hardening, which are a consequence of X-ray beam polychromaticity, are becoming an increasingly important issue affecting CT scanning as medical implants become more common in a generally aging population. The associated higher-order beam-hardening factors can be corrected via analysis of the mismatch between measured sinogram data and the ideal forward projectors in CT reconstruction by considering the known geometry of high-attenuation objects. Without prior knowledge of the spectrum parameters or energy-dependent attenuation coefficients, the proposed correction allows the background CT image (i.e., the image before its corruption by metal artifacts) to be extracted from the uncorrected CT image. Computer simulations and phantom experiments demonstrate the effectiveness of the proposed method to alleviate beam hardening artifacts.

  2. JGIXA - A software package for the calculation and fitting of grazing incidence X-ray fluorescence and X-ray reflectivity data for the characterization of nanometer-layers and ultra-shallow-implants

    Science.gov (United States)

    Ingerle, D.; Pepponi, G.; Meirer, F.; Wobrauschek, P.; Streli, C.

    2016-04-01

    Grazing incidence XRF (GIXRF) is a very surface sensitive, nondestructive analytical tool making use of the phenomenon of total external reflection of X-rays on smooth polished surfaces. In recent years the method experienced a revival, being a powerful tool for process analysis and control in the fabrication of semiconductor based devices. Due to the downscaling of the process size for semiconductor devices, junction depths as well as layer thicknesses are reduced to a few nanometers, i.e. the length scale where GIXRF is highly sensitive. GIXRF measures the X-ray fluorescence induced by an X-ray beam incident under varying grazing angles and results in angle dependent intensity curves. These curves are correlated to the layer thickness, depth distribution and mass density of the elements in the sample. But the evaluation of these measurements is ambiguous with regard to the exact distribution function for the implants as well as for the thickness and density of nanometer-thin layers. In order to overcome this ambiguity, GIXRF can be combined with X-ray reflectometry (XRR). This is straightforward, as both techniques use similar measurement procedures and the same fundamental physical principles can be used for a combined data evaluation strategy. Such a combined analysis removes ambiguities in the determined physical properties of the studied sample and, being a correlative spectroscopic method, also significantly reduces experimental uncertainties of the individual techniques. In this paper we report our approach to a correlative data analysis, based on a concurrent calculation and fitting of simultaneously recorded GIXRF and XRR data. Based on this approach we developed JGIXA (Java Grazing Incidence X-ray Analysis), a multi-platform software package equipped with a user-friendly graphic user interface (GUI) and offering various optimization algorithms. Software and data evaluation approach were benchmarked by characterizing metal and metal oxide layers on

  3. Evaluation of mammographic X-ray beams using a phosphor plate

    Energy Technology Data Exchange (ETDEWEB)

    Bustos F, M.; Prata M, A., E-mail: mbustos@ufmg.br [Universidade Federal de Minas Gerais, Departamento de Engenharia Nuclear, Av. Pte. Antonio Carlos 6627, 31270-901 Pampulha, Belo Horizonte, Minas Gerais (Brazil)

    2016-10-15

    Currently, breast cancer is the second type of cancer more with higher overall incidence recorded in 2015, more than 57,000 new cases according to the National Cancer Institute of Brazil Mammography is now one of the imaging technique most widely used worldwide for the early diagnosis of breast cancer. The computed radiography (Cr) plates are used to obtain digital radiographs, and are widely used for digital mammogram production. This study aims to evaluate the variation response in the exposure of a Cr plate in mammography unit. For this study a mammography device model Graph A F Mammo, made by Vmi and a Cr plate, model Regius, were used for mammography. Experiments were made with two X-ray beams of 20 and 25 kV. Successive exposures of the Cr plate were made in a time range time from 0.5 to 2.5 s., to obtain unprocessed images .raw and subsequently make the measurement of time, air kerma and air kerma rate using a Ray Safe Xi meter. Five measurements for each exposure time were performed and the images were analyzed using the Image J software. A matrix of 21 x 21 pixels was selected in the central region of each image to obtain the intensity value, in grey scale, for each exposure time. From these data, a correlation of the degree of darkening was made with time and the air kerma. The behavior of the curves corresponding to the intensity average values of central pixels in relation to the exposure time and air kerma are similar for both voltages,showing an initially linear behavior and then a plate saturation region, whichever occurs first at the greatest value of the applied voltage. (Author)

  4. Evaluation of mammographic X-ray beams using a phosphor plate

    International Nuclear Information System (INIS)

    Bustos F, M.; Prata M, A.

    2016-10-01

    Currently, breast cancer is the second type of cancer more with higher overall incidence recorded in 2015, more than 57,000 new cases according to the National Cancer Institute of Brazil Mammography is now one of the imaging technique most widely used worldwide for the early diagnosis of breast cancer. The computed radiography (Cr) plates are used to obtain digital radiographs, and are widely used for digital mammogram production. This study aims to evaluate the variation response in the exposure of a Cr plate in mammography unit. For this study a mammography device model Graph A F Mammo, made by Vmi and a Cr plate, model Regius, were used for mammography. Experiments were made with two X-ray beams of 20 and 25 kV. Successive exposures of the Cr plate were made in a time range time from 0.5 to 2.5 s., to obtain unprocessed images .raw and subsequently make the measurement of time, air kerma and air kerma rate using a Ray Safe Xi meter. Five measurements for each exposure time were performed and the images were analyzed using the Image J software. A matrix of 21 x 21 pixels was selected in the central region of each image to obtain the intensity value, in grey scale, for each exposure time. From these data, a correlation of the degree of darkening was made with time and the air kerma. The behavior of the curves corresponding to the intensity average values of central pixels in relation to the exposure time and air kerma are similar for both voltages,showing an initially linear behavior and then a plate saturation region, whichever occurs first at the greatest value of the applied voltage. (Author)

  5. The APS X-ray undulator photon beam position monitor and tests at CHESS and NSLS

    International Nuclear Information System (INIS)

    Shu, D.; Rodricks, B.; Barraza, J.; Sanchez, T.; Kuzay, T.M.

    1992-01-01

    The advent of thirs generation synchrotron sources, like the Advanced Photon Source (APS), will provide significant increases in brilliance over existing synchrotron sources. The APS X-ray undulators will increase the brilliance in the 3-40 keV range by several orders of magnitude. Thus, the design of the photon beam position monitor is a challenging engineering task. The beam position monitors must withstand the high thermal load, be able to achieve submicron spatial resolution while maintaining their stability, and be compatible with both undulators and wigglers. A preliminary APS prototype photon beam position monitor consisting of a CVD-diamond-based, tungsten-coated blade was tested on the APS/CHESS undulator at the Cornell High Energy Synchrotron Radiation Source (CHESS) and on the NSLS X-13 undulator beamline. Results from these tests, as well as the design of this prototype APS photon beam position monitor, will be discussed in this paper. (orig.)

  6. Evaluation of the spectral distribution of X-ray beams from measurements on the scattered radiation

    International Nuclear Information System (INIS)

    Casnati, E.; Baraldi, C.

    1980-01-01

    Most of the phenomena activated by photons with energies below 100 keV show an apparent or real dependence on the quantum energy. Therefore, knowledge of the beam energy characteristics is of primary importance for interpretation of the irradiation results. The greatest difficulty arises from the high flux density of the beams usually employed which does not allow direct measurements of the beam. A method was developed which permits evaluation of the spectral distribution of the X-ray beam from a spectrometric measurement of the radiation scattered by a thin foil of a suitable metal. This makes possible a new and more rational approach to the measurement of X-rays in the energy range where the interaction parameters show a large photon energy dependence. The corrections required by the presence of some collateral effects, among which the most important is the coexistence of the coherent and incoherent scattering, must be evaluated. The knowledge of the spectral distribution is of immediate usefulness for studies of radiation damage in biological and other materials, for the calibration of radiation measuring instruments and for the improvement of the radiological instrumentation response which contributes to reducing the patient's dose. (H.K.)

  7. Precise material identification method based on a photon counting technique with correction of the beam hardening effect in X-ray spectra

    International Nuclear Information System (INIS)

    Kimoto, Natsumi; Hayashi, Hiroaki; Asahara, Takashi; Mihara, Yoshiki; Kanazawa, Yuki; Yamakawa, Tsutomu; Yamamoto, Shuichiro; Yamasaki, Masashi; Okada, Masahiro

    2017-01-01

    The aim of our study is to develop a novel material identification method based on a photon counting technique, in which the incident and penetrating X-ray spectra are analyzed. Dividing a 40 kV X-ray spectra into two energy regions, the corresponding linear attenuation coefficients are derived. We can identify the materials precisely using the relationship between atomic number and linear attenuation coefficient through the correction of the beam hardening effect of the X-ray spectra. - Highlights: • We propose a precise material identification method to be used as a photon counting system. • Beam hardening correction is important, even when the analysis is applied to the short energy regions in the X-ray spectrum. • Experiments using a single probe-type CdTe detector were performed, and Monte Carlo simulation was also carried out. • We described the applicability of our method for clinical diagnostic X-ray imaging in the near future.

  8. Effects of growth conditions on the GaAs/AlAs superlattices by grazing incidence X-ray reflectivity.

    Science.gov (United States)

    Ren, Lingling; Gao, Huifang; Yuan, Aili

    2013-02-01

    The effects of growth conditions on the structural properties of the GaAs/AlAs superlattices were investigated by grazing incidence X-ray reflectivity (GIXRR), transmission electron microscopy (TEM), Auger electron spectroscopy (AES) and X-ray photoelectron spectroscopy (XPS). The GaAs/AlAs superlattices were prepared by molecular beam epitaxy (MBE) at different growth temperatures (500 degrees C, 600 degrees C and 660 degrees C) and growth rates (1.0 microm/h and 0.7 microm/h for GaAs). And the thicknesses, surface/interface roughnesses and densities of the GaAs/AlAs superlattices were obtained by GIXRR by fitting the whole spectral reflectance curves based on the Parratt recurrence formula. The homogeneity of samples was also studied at different growth conditions. The results indicate that the superlattices grown at a high temperature and large growth rate ratio (rate of AlAs to that of GaAs) possess better structure and more homogeneity.

  9. Investigations of the phase transition in V3O5 using energy dispersive X-ray diffraction and synchrotron radiation white beam X-ray topography

    International Nuclear Information System (INIS)

    Asbrink, S.; Gerward, L.; Staun Olsen, J.

    1985-01-01

    The reversible first order phase transition in V 3 O 5 at T t =155 0 C has been studied using a specially constructed oven, where the temperature can be kept constant within a few hundredths of a degree for several hours. Energy dispersive diffraction measurements have beem made in a temperature region around the phase transition with the fixed crystal method and the θ/2θ scanning method. White beam X-ray topographs have been obtained from the same crystal in the same temperature region using synchrotron radiation. The integrated intensities of the strong h 0 0 reflections show anomalies that are correlated with the corresponding X-ray topographs. Thus, an unexpected increase of crystal perfection is observed a few hundredths of a degree below T t . The energy dependence of the intensity maximum at T t for strong reflections has been determined and semi-quantitatively explained on the basis of extinction theory. (orig.)

  10. Creating flat-top X-ray beams by applying surface profiles of alternating curvature to deformable piezo bimorph mirrors.

    Science.gov (United States)

    Sutter, John P; Alcock, Simon G; Kashyap, Yogesh; Nistea, Ioana; Wang, Hongchang; Sawhney, Kawal

    2016-11-01

    Beam shaping is becoming increasingly important for synchrotron X-ray applications. Although routine for visible light lasers, this is challenging for X-rays due to the limited source coherence and extreme optical tolerances required for the shaping mirrors. In deliberate defocusing, even surface errors mirrors of fixed curvature. Such optics are useful for providing a fixed size of X-ray beam, but do not provide the adaptability required by many experiments. In contrast, deformable piezo bimorph mirrors permit a continuous range of X-ray beam sizes and shapes. A new theory is developed for applying non-periodic modifications of alternating curvature to optical surfaces. The position and length of the segments may be freely chosen. For the first time, surface modifications of alternating curvature are applied to bimorph mirrors to generate non-Gaussian X-ray beam profiles of specified width. The new theory's freedom is exploited to choose the segments to match the polishing errors of medium wavelength (>10 mm) and the piezos' influence on the mirror's figure. Five- and seven-segment modifications of alternating curvature are calculated and verified by visible light and X-ray metrology. The latter yields beam profiles with less striation than those made by defocusing. Remaining beam striations are explained by applying geometrical optics to the deviations from the ideal surface modifications of alternating curvature.

  11. X-ray radiation generated by a beam of relativistic electrons in composite structure

    Science.gov (United States)

    Blazhevich, S. V.; Noskov, A. V.

    2018-04-01

    The dynamic theory of coherent X-ray radiation generated by a beam of relativistic electrons in the three-layer structure consisting of an amorphous layer, a vacuum (air) layer and a single crystal has been developed. The phenomenon description is based on two main radiation mechanisms, namely, parametric X-ray radiation (PXR) and diffracted transition radiation (DTR). The possibility to increase the spectral-angular density of DTR under the condition of constructive interference of the transition radiation waves from different boundaries of such a structure has been demonstrated. It is shown that little changes in the layers thicknesses should not cause a considerable change in the interference picture, for example, the transition of constructive interference into destructive one. It means that in the considered process the conditions of constructive interference are enough stable to use them for increasing the intensity of X-ray source that can be created based on the interaction of relativistic electrons with such a structure.

  12. Central X-ray beam correction of radiographic acetabular cup measurement after THA: an experimental study.

    Science.gov (United States)

    Schwarz, T; Weber, M; Wörner, M; Renkawitz, T; Grifka, J; Craiovan, B

    2017-05-01

    Accurate assessment of cup orientation on postoperative radiographs is essential for evaluating outcome after THA. However, accuracy is impeded by the deviation of the central X-ray beam in relation to the cup and the impossibility of measuring retroversion on standard pelvic radiographs. In an experimental trial, we built an artificial cup holder enabling the setting of different angles of anatomical anteversion and inclination. Twelve different cup orientations were investigated by three examiners. After comparing the two methods for radiographic measurement of the cup position developed by Lewinnek and Widmer, we showed how to differentiate between anteversion and retroversion in each cup position by using a second plane. To show the effect of the central beam offset on the cup, we X-rayed a defined cup position using a multidirectional central beam offset. According to Murray's definition of anteversion and inclination, we created a novel corrective procedure to balance measurement errors caused by deviation of the central beam. Measurement of the 12 different cup positions with the Lewinnek's method yielded a mean deviation of [Formula: see text] (95 % CI 1.3-2.3) from the original cup anteversion. The respective deviation with the Widmer/Liaw's method was [Formula: see text] (95 % CI 2.4-4.0). In each case, retroversion could be differentiated from anteversion with a second radiograph. Because of the multidirectional central beam offset ([Formula: see text] cm) from the acetabular cup in the cup holder ([Formula: see text] anteversion and [Formula: see text] inclination), the mean absolute difference for anteversion was [Formula: see text] (range [Formula: see text] to [Formula: see text] and [Formula: see text] (range [Formula: see text] to [Formula: see text] for inclination. The application of our novel mathematical correction of the central beam offset reduced deviation to a mean difference of [Formula: see text] for anteversion and [Formula: see text

  13. Modelling microscopic features of streamer encounters, electric fields, electron beams and X-ray bursts

    Science.gov (United States)

    Koehn, C.; Kochkin, P.; Ebert, U.

    2015-12-01

    Thunderstorms emit terrestrial gamma-ray flashes (TGFs), beams of photons with quantum energies ofup to 40 MeV. Likewise electric discharges in the laboratory, mimicing lightning on a small spatial andenergetic scale, emit X-rays whose energies are limited by the available potential difference betweenthe two electrodes. For a maximal available difference of 1 MV and a gap distance of 1 m between the twoelectrodes, we will present the energy and spatial distribution of generated X-rays.For that we have followed the motion of preaccelerated, monoenergetic and monodirectional electronbeams with energies between 100 keV and the maximal available energy of 1 MeV for different electricfield configurations using a particle Monte Carlo code. Omitting any field, we present the subsequent energy and spatial distribution of X-raysand analyse how the photon number depends on the initial electron energy. Fig. 1 shows the position and energy of photons generated by Bremsstrahlung after 0.3 ns by beams of 500 000 electrons with initial energies of 1 MeV moving in the zdirection in STP air. The electrons have generated electron avalanches and all have cooleddown and attached to oxygen after 0.3 ns. Every cross represents one photon projected onto the xz plane; the photon energies Eγ are color coded. We see that photons with energies of approx. 1 MeV can be produced and that the high-energy tail of X-rays is beamedtowards the direction of the initial electron beam whereas low-energy photons show a more isotropicbehaviour. Analysing the cross sections of photons interacting with air we conclude that photons travelseveral meters in air and can reach detectors several meters from the position of the discharge. Byestimating the electric field ahead of the discharge corona and by simulating the motion of electronbeams in these fields, we exclude that electrons travel as far as photons and disturb the measured X-raysignal.

  14. Development of glancing-incidence and glancing-take-off X-ray fluorescence apparatus for surface and thin-film analyses

    International Nuclear Information System (INIS)

    Tsuji, Kouichi; Wagatsuma, Kazuaki; Yamada, Takashi; Utaka, Tadashi

    1997-01-01

    We have studied X-ray fluorescence analysis under glancing incidence and glancing take-off conditions. Recently, we have developed a third apparatus for detecting glancing-incidence and take-off X-ray fluorescence, which makes it possible to measure the incident-angle dependence, the take-off-angle dependence. X-ray reflectivity, and X-ray diffraction. Primarily, we have measured the take-off angular dependence of X-ray fluorescence using this apparatus. Glancing take-off X-ray fluorescence has some advantages in comparison with glancing-incidence X-ray fluorescence. The surface density and the absolute angles were determined by analysing the take-off angle dependence of the fluorescent X-rays emitted from identical atoms with the aid of the reciprocity theorem. (Author)

  15. Survey on th incidence of homeless pulmonary tuberculosis infection rate through chest x-ray examination

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Mi Young; Shin, Sung Rae [Dept. of Nursing, Sahmyook University, Seoul (Korea, Republic of); Ryu, Young Hwan [Dept. of Radiology, Seoul Medical Center, Seoul (Korea, Republic of); Lim, Hwan Yeal [Dept. of Medical Business Administration, U1 University, Yeongdong (Korea, Republic of)

    2017-02-15

    This study, Seoul City shelter, you are trying to seek medical cooperation and cure rate increase proposal Yu fndings’s current situation and tuberculosis of homeless tuberculosis. Inspector, and has a total 591 people is targeted to implement an interview after acquiring utilization agreement in studies conducted chest X-ray photography. Of the interview questions, three or more protons, it is determined that the TB symptomatic conducted sputum examination, chest X-ray examination confrms the physician radiology, when sputum examination primarily chromatic fndings the double implemented and conducted by requesting the ship inspection also said inspection sputum acid-fast bacteria if it is true one, respectively. confrmed case result of checking whether there is a difference due to risk factors (Jb) at the chi square black, it was found that there is no statistically significant difference at 95% confidence level. (χ{sup 2}=0.276, p>0.05), suspected case (Ac, Ae) results of examining whether there is a difference due to risk factors in chi square black, that there is a statistically significant difference at 99% confidence level is I found (χ{sup 2}=9.414, p<0.01). The nature of the homeless tuberculosis screening and directed to the distance homeless specifc location are likely to evaluate the actual incidence low and aggressive or management needs, the rationale is allowed insufficient reality is. Through this research, future, for tuberculosis high risk tuberculosis patient, such as homeless to expand the tuberculosis screening of infectious tuberculosis patients in private medical institutions, and one-stop service that chest X-ray examination and sputum examination is carried out at the same time introduced immediately to prevent the inspection and examination, cure, and should establish a foundation that can be up to post administration.

  16. Survey on th incidence of homeless pulmonary tuberculosis infection rate through chest x-ray examination

    International Nuclear Information System (INIS)

    Kim, Mi Young; Shin, Sung Rae; Ryu, Young Hwan; Lim, Hwan Yeal

    2017-01-01

    This study, Seoul City shelter, you are trying to seek medical cooperation and cure rate increase proposal Yu fndings’s current situation and tuberculosis of homeless tuberculosis. Inspector, and has a total 591 people is targeted to implement an interview after acquiring utilization agreement in studies conducted chest X-ray photography. Of the interview questions, three or more protons, it is determined that the TB symptomatic conducted sputum examination, chest X-ray examination confrms the physician radiology, when sputum examination primarily chromatic fndings the double implemented and conducted by requesting the ship inspection also said inspection sputum acid-fast bacteria if it is true one, respectively. confrmed case result of checking whether there is a difference due to risk factors (Jb) at the chi square black, it was found that there is no statistically significant difference at 95% confidence level. (χ 2 =0.276, p>0.05), suspected case (Ac, Ae) results of examining whether there is a difference due to risk factors in chi square black, that there is a statistically significant difference at 99% confidence level is I found (χ 2 =9.414, p<0.01). The nature of the homeless tuberculosis screening and directed to the distance homeless specifc location are likely to evaluate the actual incidence low and aggressive or management needs, the rationale is allowed insufficient reality is. Through this research, future, for tuberculosis high risk tuberculosis patient, such as homeless to expand the tuberculosis screening of infectious tuberculosis patients in private medical institutions, and one-stop service that chest X-ray examination and sputum examination is carried out at the same time introduced immediately to prevent the inspection and examination, cure, and should establish a foundation that can be up to post administration

  17. Image covariance and lesion detectability in direct fan-beam x-ray computed tomography.

    Science.gov (United States)

    Wunderlich, Adam; Noo, Frédéric

    2008-05-21

    We consider noise in computed tomography images that are reconstructed using the classical direct fan-beam filtered backprojection algorithm, from both full- and short-scan data. A new, accurate method for computing image covariance is presented. The utility of the new covariance method is demonstrated by its application to the implementation of a channelized Hotelling observer for a lesion detection task. Results from the new covariance method and its application to the channelized Hotelling observer are compared with results from Monte Carlo simulations. In addition, the impact of a bowtie filter and x-ray tube current modulation on reconstruction noise and lesion detectability are explored for full-scan reconstruction.

  18. Computer simulations of X-ray six-beam diffraction in a perfect silicon crystal. I

    Czech Academy of Sciences Publication Activity Database

    Kohn, V.G.; Khikhlukha, Danila

    2016-01-01

    Roč. 72, May (2016), s. 349-356 ISSN 2053-2733 R&D Projects: GA MŠk EF15_008/0000162; GA MŠk ED1.1.00/02.0061 Grant - others:ELI Beamlines(XE) CZ.02.1.01/0.0/0.0/15_008/0000162; ELI Beamlines(XE) CZ.1.05/1.1.00/02.0061 Institutional support: RVO:68378271 Keywords : X-ray diffraction * silicon crystal * six-beam diffraction * section topography * computer simulations Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 5.725, year: 2016

  19. A novel process control method for a TT-300 E-Beam/X-Ray system

    Science.gov (United States)

    Mittendorfer, Josef; Gallnböck-Wagner, Bernhard

    2018-02-01

    This paper presents some aspects of the process control method for a TT-300 E-Beam/X-Ray system at Mediscan, Austria. The novelty of the approach is the seamless integration of routine monitoring dosimetry with process data. This allows to calculate a parametric dose for each production unit and consequently a fine grain and holistic process performance monitoring. Process performance is documented in process control charts for the analysis of individual runs as well as historic trending of runs of specific process categories over a specified time range.

  20. Philips high tension generator (x-ray machine) testing for baby ebm (electron beam machine) project

    International Nuclear Information System (INIS)

    Norman Awalludin; Leo Kwee Wah; Abu Bakar Mhd Ghazali

    2005-01-01

    This paper describes the test of the HT system (from X-ray machine) for usage of the mini EBM (Electron Beam Machine). It consists the procedures of the installation, the safety procedures when deals with HT, modification of the system for testing purpose and the technique/method for testing the HT system. As a result, the voltage for the HT system and the electron gun (filament) current can be measured. Based on the results, suitability of the machine for baby EBM could be confirmed. (Author)

  1. Semi-empirical model for fluorescence lines evaluation in diagnostic x-ray beams.

    Science.gov (United States)

    Bontempi, Marco; Andreani, Lucia; Labanti, Claudio; Costa, Paulo Roberto; Rossi, Pier Luca; Baldazzi, Giuseppe

    2016-01-01

    Diagnostic x-ray beams are composed of bremsstrahlung and discrete fluorescence lines. The aim of this study is the development of an efficient model for the evaluation of the fluorescence lines. The most important electron ionization models are analyzed and implemented. The model results were compared with experimental data and with other independent spectra presented in the literature. The implemented peak models allow the discrimination between direct and indirect radiation emitted from tungsten anodes. The comparison with the independent literature spectra indicated a good agreement. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Image covariance and lesion detectability in direct fan-beam x-ray computed tomography

    International Nuclear Information System (INIS)

    Wunderlich, Adam; Noo, Frederic

    2008-01-01

    We consider noise in computed tomography images that are reconstructed using the classical direct fan-beam filtered backprojection algorithm, from both full- and short-scan data. A new, accurate method for computing image covariance is presented. The utility of the new covariance method is demonstrated by its application to the implementation of a channelized Hotelling observer for a lesion detection task. Results from the new covariance method and its application to the channelized Hotelling observer are compared with results from Monte Carlo simulations. In addition, the impact of a bowtie filter and x-ray tube current modulation on reconstruction noise and lesion detectability are explored for full-scan reconstruction

  3. X-ray interferometry with transmissive beam combiners for ultra-high angular resolution astronomy

    OpenAIRE

    Skinner, G. K.; Krizmanic, J. F.

    2009-01-01

    Interferometry provides one of the possible routes to ultra-high angular resolution for X-ray and gamma-ray astronomy. Sub-micro-arc-second angular resolution, necessary to achieve objectives such as imaging the regions around the event horizon of a super-massive black hole at the center of an active galaxy, can be achieved if beams from parts of the incoming wavefront separated by 100s of meters can be stably and accurately brought together at small angles. One way of achieving this is by us...

  4. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... standards used by radiology professionals. Modern x-ray systems have very controlled x-ray beams and dose ... Medicine Radiation Safety How to Read Your Radiology Report Images related to X-ray (Radiography) - Bone Sponsored ...

  5. Pulse-periodic generation of supershort avalanche electron beams and X-ray emission

    Science.gov (United States)

    Baksht, E. Kh.; Burachenko, A. G.; Erofeev, M. V.; Tarasenko, V. F.

    2014-05-01

    Pulse-periodic generation of supershort avalanche electron beams (SAEBs) and X-ray emission in nitrogen, as well as the transition from a single-pulse mode to a pulse-periodic mode with a high repetition frequency, was studied experimentally. It is shown that, in the pulse-periodic mode, the full width at halfmaximum of the SAEB is larger and the decrease rate of the gap voltage is lower than those in the single-pulse mode. It is found that, when the front duration of the voltage pulse at a nitrogen pressure of 90 Torr decreases from 2.5 to 0.3 ns, the X-ray exposure dose in the pulse-periodic mode increases by more than one order of magnitude and the number of SAEB electrons also increases. It is shown that, in the pulse-periodic mode of a diffuse discharge, gas heating in the discharge gap results in a severalfold increase in the SAEB amplitude (the number of electrons in the beam). At a generator voltage of 25 kV, nitrogen pressure of 90 Torr, and pulse repetition frequency of 3.5 kHz, a runaway electron beam was detected behind the anode foil.

  6. Supershort avalanche electron beams and x-ray in high-pressure nanosecond discharges

    International Nuclear Information System (INIS)

    Tarasenko, V F; Baksht, E H; Kostyrya, I D; Lomaev, M I; Rybka, D V

    2008-01-01

    The properties of a supershort avalanche electron beam (S AEB) and X-ray radiation produced using a nanosecond volume discharge are examined. An electron beam of the runaway electrons with amplitude of ∼ 50 A has been obtained in air atmospheric pressure. It is reported that S AEB is formed in the angle above 2π sr. Three groups of the runaway electrons are formed in a gas diode under atmospheric air pressure, when nanosecond voltage pulses with amplitude of hundreds of kilovolts are applied. The electron beam has been generated behind a 45 μm thick AlBe foil in SF 6 and Xe under the pressure of 2 arm, and in He under the pressure of about 12 atm. The paper gives the analysis of a generation mechanism of SAEB.

  7. UV/X-Ray Diffraction Radiation for non-intercepting Micron-Scale Beam Size Measurement

    CERN Document Server

    -; Lefevre, T; Karataev, P; Billing, M

    2012-01-01

    Diffraction radiation (DR) is produced when a relativistic charged particle moves in the vicinity of a medium. The electric field of the charged particle polarizes the target atoms which then oscillate, emitting radiation with a very broad spectrum. The spatial-spectral properties of DR are sensitive to a range of electron beam parameters. Furthermore, the energy loss due to DR is so small that the electron beam parameters are unchanged. Therefore DR can be used to develop non-invasive diagnostic tools. The aim of this project is to measure the transverse (vertical) beam size using incoherent DR. To achieve the micron-scale resolution required by CLIC, DR in UV and X-ray spectral-range must be investigated. During the next few years, experimental validation of such a scheme will be conducted on the CesrTA at Cornell University, USA. Here we present the current status of the experiment preparation.

  8. Beam profile control of line focus for x-ray laser experiment

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, G.Y.; Jitsuno, T.; Nakatsuka, M.; Daido, H.; Kato, Y.; Nakai, S. [Osaka Univ., Suita, Osaka (Japan). Inst. of Laser Engineering

    1995-12-31

    A high aspect ratio line focus on a target for the x-ray laser experiments is required for obtaining a high gain-length product. A new line focus system is developed to generate a uniform line focus. The system consists of a deformable mirror of a continuous faceplate type which provides an appropriate wavefront distribution for compensating an aberration of a line focus optics. The width and intensity distribution of 18.2mm long line focus have been improved on 2 times diffraction limit. As other application, a rectangular beam shaping from a circular defocused beam is investigated by the experiment and the diffraction calculation. The controllability of intensity distribution of laser beam by deformable mirror has been demonstrated.

  9. Optimization of phosphor-based detector design for oblique x-ray incidence in digital breast tomosynthesis.

    Science.gov (United States)

    Acciavatti, Raymond J; Maidment, Andrew D A

    2011-11-01

    In digital breast tomosynthesis (DBT), a volumetric reconstruction of the breast is generated from a limited range of x-ray projections. One trade-off of DBT is resolution loss in the projections due to non-normal (i.e., oblique) x-ray incidence. Although degradation in image quality due to oblique incidence has been studied using empirical data and Monte Carlo simulations, a theoretical treatment has been lacking. The purpose of this work is to extend Swank's calculations of the transfer functions of turbid granular phosphors to oblique incidence. The model is ultimately used as a tool for optimizing the design of DBT detectors. A quantum-limited system and 20 keV x-rays are considered. Under these assumptions, the modulation transfer function (MTF) and noise power spectra (NPS) are derived using the diffusion approximation to the Boltzmann equation to model optical scatter within the phosphor. This approach is applicable to a nonstructured scintillator such as gadolinium oxysulfide doped with terbium (Gd(2)O(2)S:Tb), which is commonly used in breast imaging and which can reasonably approximate other detector materials. The detective quantum efficiency (DQE) is then determined from the Nishikawa formulation, where it is written as the product of the x-ray quantum detection efficiency, the Swank factor, and the Lubberts fraction. Transfer functions are calculated for both front- and back-screen configurations, which differ by positioning the photocathode at the exit or entrance point of the x-ray beam, respectively. In the front-screen configuration, MTF and DQE are found to have considerable angular dependence, while NPS is shown to vary minimally with projection angle. As expected, the high frequency MTF and DQE are degraded substantially at large angles. By contrast, all transfer functions for the back-screen configuration have the advantage of significantly less angular dependence. Using these models, we investigated the possibility for optimizing the design of

  10. An empirical model of diagnostic x-ray attenuation under narrow-beam geometry

    International Nuclear Information System (INIS)

    Mathieu, Kelsey B.; Kappadath, S. Cheenu; White, R. Allen; Atkinson, E. Neely; Cody, Dianna D.

    2011-01-01

    Purpose: The purpose of this study was to develop and validate a mathematical model to describe narrow-beam attenuation of kilovoltage x-ray beams for the intended applications of half-value layer (HVL) and quarter-value layer (QVL) estimations, patient organ shielding, and computer modeling. Methods: An empirical model, which uses the Lambert W function and represents a generalized Lambert-Beer law, was developed. To validate this model, transmission of diagnostic energy x-ray beams was measured over a wide range of attenuator thicknesses [0.49-33.03 mm Al on a computed tomography (CT) scanner, 0.09-1.93 mm Al on two mammography systems, and 0.1-0.45 mm Cu and 0.49-14.87 mm Al using general radiography]. Exposure measurements were acquired under narrow-beam geometry using standard methods, including the appropriate ionization chamber, for each radiographic system. Nonlinear regression was used to find the best-fit curve of the proposed Lambert W model to each measured transmission versus attenuator thickness data set. In addition to validating the Lambert W model, we also assessed the performance of two-point Lambert W interpolation compared to traditional methods for estimating the HVL and QVL [i.e., semilogarithmic (exponential) and linear interpolation]. Results: The Lambert W model was validated for modeling attenuation versus attenuator thickness with respect to the data collected in this study (R 2 > 0.99). Furthermore, Lambert W interpolation was more accurate and less sensitive to the choice of interpolation points used to estimate the HVL and/or QVL than the traditional methods of semilogarithmic and linear interpolation. Conclusions: The proposed Lambert W model accurately describes attenuation of both monoenergetic radiation and (kilovoltage) polyenergetic beams (under narrow-beam geometry).

  11. Adjustable Grazing Incidence X-ray Optics with 0.5 Arc Second Resolution

    Science.gov (United States)

    Reid, Paul

    We seek to develop adjustable grazing incidence optics for x-ray astronomy. The goal of this development is thin, lightweight mirrors with angular resolution of 0.5 arc seconds, comparable to the Chandra X-ray Observatory. The new mirror design consists of thin segments of a Wolter-I grazing incidence mirror, with piezo-electric material deposited directly on the back surface of the mirror. Depositing a pattern of independently addressable electrodes on top of the piezoelectric material produces an array of independent piezo cells. Energizing a particular cell introduces a localized deformation in the mirror without the need for a reaction structure. By applying the appropriate voltage to the piezo cells, it is possible to correct mirror figure errors that result from mirror fabrication, gravity release, mounting, and thermal effects. Because the thin mirrors segments are lightweight, they can be densely nested to produce collecting area thirty times that of Chandra, on an affordably priced mission. This Supporting Technology program is a follow-on to an existing APRA program. In the existing program we demonstrated the first successful deposition of piezoelectric material on thermally formed glass substrates. We showed that the localized deformations produced by the piezo cells match finite element predictions, and the piezo cell adjustment range meets requirements necessary to achieve the desired figure correction. We have also shown through simulation that representative mirror figure errors can be corrected via modeled influence functions to achieve 0.5 arc sec imaging performance. This provides a firm foundation on which to develop further the technology. We will continue to optimize the deposition of thin piezoelectric films onto thermally formed glass and electroplated metal mirror segments to improve yield and manufacturability. We will deposit piezoelectric material onto conical mirror segments and demonstrate figure correction in agreement with prediction

  12. Radiation dose response of N channel MOSFET submitted to filtered X-ray photon beam

    Science.gov (United States)

    Gonçalves Filho, Luiz C.; Monte, David S.; Barros, Fabio R.; Santos, Luiz A. P.

    2018-01-01

    MOSFET can operate as a radiation detector mainly in high-energy photon beams, which are normally used in cancer treatments. In general, such an electronic device can work as a dosimeter from threshold voltage shift measurements. The purpose of this article is to show a new way for measuring the dose-response of MOSFETs when they are under X-ray beams generated from 100kV potential range, which is normally used in diagnostic radiology. Basically, the method consists of measuring the MOSFET drain current as a function of the radiation dose. For this the type of device, it has to be biased with a high value resistor aiming to see a substantial change in the drain current after it has been irradiated with an amount of radiation dose. Two types of N channel device were used in the experiment: a signal transistor and a power transistor. The delivered dose to the device was varied and the electrical curves were plotted. Also, a sensitivity analysis of the power MOSFET response was made, by varying the tube potential of about 20%. The results show that both types of devices have responses very similar, the shift in the electrical curve is proportional to the radiation dose. Unlike the power MOSFET, the signal transistor does not provide a linear function between the dose rate and its drain current. We also have observed that the variation in the tube potential of the X-ray equipment produces a very similar dose-response.

  13. Reduction of variable-truncation artifacts from beam occlusion during in situ x-ray tomography

    DEFF Research Database (Denmark)

    Borg, Leise; Jørgensen, Jakob Sauer; Frikel, Jürgen

    2017-01-01

    Many in situ x-ray tomography studies require experimental rigs which may partially occlude the beam and cause parts of the projection data to be missing. In a study of fluid flow in porous chalk using a percolation cell with four metal bars drastic streak artifacts arise in the filtered backproj......Many in situ x-ray tomography studies require experimental rigs which may partially occlude the beam and cause parts of the projection data to be missing. In a study of fluid flow in porous chalk using a percolation cell with four metal bars drastic streak artifacts arise in the filtered...... backprojection (FBP) reconstruction at certain orientations. Projections with non-trivial variable truncation caused by the metal bars are the source of these variable-truncation artifacts. To understand the artifacts a mathematical model of variable-truncation data as a function of metal bar radius and distance...... and artifact-reduction methods are designed in context of FBP reconstruction motivated by computational efficiency practical for large, real synchrotron data. While a specific variable-truncation case is considered, the proposed methods can be applied to general data cut-offs arising in different in situ x...

  14. Characterization of low energy X-rays beams with an extrapolation chamber

    International Nuclear Information System (INIS)

    Bastos, Fernanda Martins

    2015-01-01

    In laboratories involving Radiological Protection practices, it is usual to use reference radiations for calibrating dosimeters and to study their response in terms of energy dependence. The International Organization for Standardization (ISO) established four series of reference X-rays beams in the ISO- 4037 standard: the L and H series, as low and high air Kerma rates, respectively, the N series of narrow spectrum and W series of wide spectrum. The X-rays beams with tube potential below 30 kV, called 'low energy beams' are, in most cases, critical as far as the determination of their parameters for characterization purpose, such as half-value layer. Extrapolation chambers are parallel plate ionization chambers that have one mobile electrode that allows variation of the air volume in its interior. These detectors are commonly used to measure the quantity Absorbed Dose, mostly in the medium surface, based on the extrapolation of the linear ionization current as a function of the distance between the electrodes. In this work, a characterization of a model 23392 PTW extrapolation chamber was done in low energy X-rays beams of the ISO- 4037 standard, by determining the polarization voltage range through the saturation curves and the value of the true null electrode spacing. In addition, the metrological reliability of the extrapolation chamber was studied with measurements of the value of leakage current and repeatability tests; limit values were established for the proper use of the chamber. The PTW23392 extrapolation chamber was calibrated in terms of air Kerma in some of the ISO radiation series of low energy; the traceability of the chamber to the National Standard Dosimeter was established. The study of energy dependency of the extrapolation chamber and the assessment of the uncertainties related to the calibration coefficient were also done; it was shown that the energy dependence was reduced to 4% when the extrapolation technique was used. Finally, the first

  15. Measurements of the sensitivity and spatial resolution of radiochromic film using ion beams and X-rays

    Science.gov (United States)

    Schepis, M. J.; Shortino, J. P.; Crompton, K. R.; Stillman, C. R.; Freeman, C. G.; Nilson, P. M.; Sorce, C.; Sangster, T. C.

    2012-10-01

    Radiochromic film (RCF) is used to study protons and other ions that are accelerated from the rear side of targets illuminated with ultra-intense laser light. An experiment is underway to measure the sensitivity of RCF to protons and alpha particles of various energies using the 1.7 MV tandem Pelletron accelerator at SUNY Geneseo. An ion beam incident on a gold foil is used to expose the RCF to elastically scattered ions in a 28-inch diameter scattering chamber. The film is positioned in a circular arc in the chamber so the scattered ion fluence on the RCF strip varies as a function of the scattering angle. After exposure, the RCF is scanned in color negative transmission mode using an Epson 10000 XL flatbed scanner. The red channel of the resulting scan is used to determine the optical density of the film. The spatial resolution of the film was measured by blocking part of the film with a tantalum knife edge. The sensitivity of RCF to X-rays was also measured by exposing the film to X-rays produced by a biological irradiator. The response of the new Gafchromic HD-V2 radiochromic film is compared with the discontinued Gafchromic HD radiochromic film.

  16. Study of combined concurrent chemoradiotherapy using proton beam and X-ray

    International Nuclear Information System (INIS)

    Sasaki, Makoto; Tamamura, Hiroyasu; Shibata, Satoshi

    2016-01-01

    Esophageal cancer and head and neck cancer are prone to metastases in lymph node since early disease stage. In treatment for these tumors, it is necessary to consider overall treatment method together with treatment to the wide preventing region as well as to the local region including a tumor and a lymph node metastasis. Although a concurrent chemoradiotherapy is recommended as a standard treatment to esophageal cancer of stage I ∼ III as well as a surgical operation, the adverse event to the surrounding organs by a high dose x-ray irradiation both in wide and local region is a significant problem. Therefore, the new 'combined concurrent chemoradiotherapy', which changed a part of the x-ray irradiation in conventional concurrent chemoradiotherapy to proton beam irradiation with the high local concentration, was contrived in this hospital. In order to achieve this treatment, we constructed the system which enables the overall evaluation of the prescription dose and dose distribution by accumulating the ones independently calculated in x-ray radiotherapy planning and proton radiotherapy planning. In addition, in order to achieve the safe and effective treatment in every case, we established the treatment practical use with which many medical staff, such as gastrointestinal physicians, surgeons, radiation oncologists, medical physicists, radiological technologists, and nurses in a general hospital, could cooperate. As a result, the serious acute-phase adverse event is not admitted in our early experience of the combined concurrent chemoradiotherapy for advanced esophageal cancer. By a follow-up including late-onset adverse event, it is expected that the combined concurrent chemoradiotherapy can reduce influence to surrounding organs. On the other hand, it is also important to establish the most suitable tumor control protocol. As a result of the experiments in the Wakasa-wan energy research center, it was found that the cytotoxic effect by irradiation

  17. A Monte Carlo approach for simulating the propagation of partially coherent x-ray beams

    DEFF Research Database (Denmark)

    Prodi, A.; Bergbäck Knudsen, Erik; Willendrup, Peter Kjær

    2011-01-01

    by sampling Huygens-Fresnel waves with Monte Carlo methods and is used to propagate each source realization to the detector plane. The sampling is implemented with a modified Monte Carlo ray tracing scheme where the optical path of each generated ray is stored. Such information is then used in the summation...... coherence function (MCF) are propagated to the exit plane. Here we present an approach based on Monte Carlo sampling of the Green function. A Gauss-Shell Stochastic Source with arbitrary spatial coherence is synthesized by means of the Gaussian copula statistical tool. The Green function is obtained......Advances at SR sources in the generation of nanofocused beams with a high degree of transverse coherence call for effective techniques to simulate the propagation of partially coherent X-ray beams through complex optical systems in order to characterize how coherence properties such as the mutual...

  18. X-ray streak camera for observation of tightly pinched relativistic electron beams

    International Nuclear Information System (INIS)

    Johnson, D.J.

    1977-01-01

    A pinhole camera is coupled with a Pilot-B scintillator and image-intensified TRW streak camera to study pinched electron beam profiles via observation of anode target bremsstrahlung. Streak intensification is achieved with an EMI image intensifier operated at a gain of up to 10 6 which allows optimizing the pinhole configuration so that resolution is simultaneously limited by photon-counting statistics and pinhole geometry. The pinhole used is one-dimensional and is fabricated by inserting uranium shims with hyperbolic curved edges between two 5-cm-thick lead blocks. The loss of spatial resolution due to the x-ray transmission through the perimeter of the pinhole is calculated and a streak photograph of a Gamble I pinched beam interacting with a brass anode is presented

  19. Application of white-beam X-ray microdiffraction for the study of mineralogical phase identification in ancient Egyptian pigments

    OpenAIRE

    Lynch, P.A.; Tamura, N.; Lau, D.; Madsen, I.; Liang, D.; Strohschnieder, M.; Stevenson, A.W.

    2007-01-01

    High-brightness synchrotron X-rays together with precision achromatic focusing optics on beamline 7.3.3 at the Advanced Light Source have been applied for Laue microdiffraction analysis of mineralogical phases in Egyptian pigments. Although this task is usually performed using monochromatic X-ray diffraction, the Laue technique was both faster and more reliable for the present sample. In this approach, white-beam diffraction patterns are collected as the sample is raster scanned across the in...

  20. Measurement of conversion coefficients between air Kerma and personal dose equivalent and backscatter factors for diagnostic X-ray beams

    International Nuclear Information System (INIS)

    Rosado, Paulo Henrique Goncalves

    2008-01-01

    Two sets of quantities are import in radiological protection: the protection and operational quantities. Both sets can be related to basic physical quantities such as kerma through conversion coefficients. For diagnostic x-ray beams the conversion coefficients and backscatter factors have not been determined yet, those parameters are need for calibrating dosimeters that will be used to determine the personal dose equivalent or the entrance skin dose. Conversion coefficients between air kerma and personal dose equivalent and backscatter factors were experimentally determined for the diagnostic x-ray qualities RQR and RQA recommended by the International Electrotechnical Commission (IEC). The air kerma in the phantom and the mean energy of the spectrum were measured for such purpose. Harshaw LiF-100H thermoluminescent dosemeters (TLD) were used for measurements after being calibrated against an 180 cm 3 Radcal Corporation ionization chamber traceable to a reference laboratory. A 300 mm x 300 mm x 150 mm polymethylmethacrylate (PMMA) slab phantom was used for deep-dose measurements. Tl dosemeters were placed in the central axis of the x-ray beam at 5, 10, 15, 25 and 35 mm depth in the phantom upstream the beam direction Another required parameter for determining the conversion coefficients from was the mean energy of the x-ray spectrum. The spectroscopy of x-ray beams was done with a CdTe semiconductor detector that was calibrated with 133 Ba, 241 Am and 57 Co radiation sources. Measurements of the x-ray spectra were carried out for all RQR and RQA IEC qualities. Corrections due to the detector intrinsic efficiency, total energy absorption, escape fraction of the characteristic x-rays, Compton effect and attenuation in the detector were done aiming an the accurate determination of the mean energy. Measured x-ray spectra were corrected with the stripping method by using these response functions. The typical combined standard uncertainties of conversion coefficients and

  1. Skin dose from radiotherapy X-ray beams: the influence of energy

    International Nuclear Information System (INIS)

    Butson, M.J.; Metcalfe, P.E.; University of Wollongong, Wollongong, NSW; Mathur, J.N.

    1997-01-01

    Skin-sparing properties of megavoltage photon beams are compromised by electron contamination. Higher energy beams do not necessarily produce lower surface and basal cell layer doses due to this electron contamination. For a 5x5 cm field size the surface doses for 6 MVp and 18 M)p X-ray beams are 10% and 7% of their respective maxima. However, at a field size of 40 x 40cm the percentage surface dose is 42% for both 6 MVp and 18 MVp beams. The introduction of beam modifying devices such as block trays can further reduce the skin-sparing advantages of high energy photon beams. Using a 10 mm perspex block tray, the surface doses for 6 MVp and 18 MVp beams with a 5 x 5 cm field size are 10% and 8%, respectively. At 40 x 40cm, surface doses are 61% and 63% for 6 MVp and 18 MVp beams, respectively. This trend is followed at the basal cell layer depth. At a depth of 1 mm, 18 MVp beam doses are always at least 5% smaller than 6 MVp doses for the same depth at all field sizes when normalized to their respective Dmax values. Results have shown that higher energy photon beams produce a negligible reduction of the delivered dose to the basal cell layer (0.1 mm). Only a small increase in skin sparing is seen at the dermal layer (1 mm), which can be negated by the increased exit dose from an opposing field. (authors)

  2. A portable Compton spectrometer for clinical X-ray beams in the energy range 20-150 keV

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, A.A. [Departamento de Fisica, Pontificia Universidade Catolica de Sao Paulo (PUC-SP), Rua Marques de Paranagua, 111-01303-050 Sao Paulo, SP (Brazil); Linke, A. [Instituto de Fisica-Universidade de Sao Paulo, Rua do Matao, 187-Travessa R-05508-900 Sao Paulo, SP (Brazil); Yoshimura, E.M., E-mail: e.yoshimura@dfn.if.usp.b [Instituto de Fisica-Universidade de Sao Paulo, Rua do Matao, 187-Travessa R-05508-900 Sao Paulo, SP (Brazil); Terini, R.A., E-mail: rterini@pucsp.b [Departamento de Fisica, Pontificia Universidade Catolica de Sao Paulo (PUC-SP), Rua Marques de Paranagua, 111-01303-050 Sao Paulo, SP (Brazil); Instituto de Eletrotecnica e Energia-Universidade de Sao Paulo, Av. Prof. Luciano Gualberto, 1289-05508-900 Sao Paulo, SP (Brazil); Herdade, S.B., E-mail: sherdade@iee.usp.b [Instituto de Fisica-Universidade de Sao Paulo, Rua do Matao, 187-Travessa R-05508-900 Sao Paulo, SP (Brazil); Instituto de Eletrotecnica e Energia-Universidade de Sao Paulo, Av. Prof. Luciano Gualberto, 1289-05508-900 Sao Paulo, SP (Brazil)

    2011-02-15

    Primary beam spectra were obtained for an X-ray industrial equipment (40-150 kV), and for a clinical mammography apparatus (25-35 kV) from beams scattered at angles close to 90{sup o}, measured with a CdTe Compton spectrometer. Actual scattering angles were determined from the Compton energy shift of characteristic X-rays or spectra end-point energy. Evaluated contribution of coherent scattering amounts to more than 15% of fluence in mammographic beams. This technique can be used in clinical environments.

  3. A portable Compton spectrometer for clinical X-ray beams in the energy range 20-150 keV

    International Nuclear Information System (INIS)

    Vieira, A.A.; Linke, A.; Yoshimura, E.M.; Terini, R.A.; Herdade, S.B.

    2011-01-01

    Primary beam spectra were obtained for an X-ray industrial equipment (40-150 kV), and for a clinical mammography apparatus (25-35 kV) from beams scattered at angles close to 90 o , measured with a CdTe Compton spectrometer. Actual scattering angles were determined from the Compton energy shift of characteristic X-rays or spectra end-point energy. Evaluated contribution of coherent scattering amounts to more than 15% of fluence in mammographic beams. This technique can be used in clinical environments.

  4. A Laue-Bragg monolithic beam splitter for efficient X-ray 2-beam imaging

    Czech Academy of Sciences Publication Activity Database

    Oberta, Peter; Mokso, R.

    2013-01-01

    Roč. 703, MAR (2013), s. 59-63 ISSN 0168-9002 R&D Projects: GA MPO FR-TI1/412 Institutional research plan: CEZ:AV0Z10100522 Keywords : X-ray imaging * Laue-Bragg diffraction * monolithic crystal * dueal energy option Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.316, year: 2013 http://www. science direct.com/ science /article/pii/S0168900212013794

  5. Nanoscale radiation transport and clinical beam modeling for gold nanoparticle dose enhanced radiotherapy (GNPT) using X-rays.

    Science.gov (United States)

    Zygmanski, Piotr; Sajo, Erno

    2016-01-01

    We review radiation transport and clinical beam modelling for gold nanoparticle dose-enhanced radiotherapy using X-rays. We focus on the nanoscale radiation transport and its relation to macroscopic dosimetry for monoenergetic and clinical beams. Among other aspects, we discuss Monte Carlo and deterministic methods and their applications to predicting dose enhancement using various metrics.

  6. Synchrotron X-ray micro-beam studies of ancient Egyptian make-up

    International Nuclear Information System (INIS)

    Martinetto, P.; Anne, M.; Dooryhee, E.; Drakopoulos, M.; Dubus, M.; Salomon, J.; Simionovici, A.; Walter, Ph.

    2001-01-01

    Vases full of make-up are most often present in the burial furniture of Egyptian tombs dated from the pharaonic period. The powdered cosmetics made of isolated grains are analysed to identify their trace element signature. From this signature we identify the provenance of the mineral ingredients in the make-up and we observe different impurities in products, which have been demonstrated as synthetic substances by previous works. Focused X-ray micro-beam (2x5 μm 2 ) is successively tuned at 11 keV, below the L III absorption edge of Pb, and 31.8 keV for global characterisation of the metal impurities. The fluorescence signal integrated over each single grain is detected against the X-ray micro-diffraction pattern collected in transmission with a bi-dimensional detector. Furthermore, for galena grains rich in Zn, the XANES signal at the K-absorption edge of Zn shows its immediate nearest-neighbour environment

  7. X-Ray Measurements Using a Microcalorimeter on an Electron Beam Ion Trap

    International Nuclear Information System (INIS)

    Silver, E.; Brickhouse, N. S.; Chen, G. X.; Kirby, K.; Gillaspy, J. D.; Tan, J. N.; Pomeroy, J. M.; Laming, J. M.

    2007-01-01

    The X-ray telescopes and spectrometers flown on Chandra and XMM-Newton are returning exciting new data from a wide variety of cosmic sources such as stellar coronae, supernova remnants, galaxies, clusters of galaxies, active galactic nuclei and X-ray binaries. To achieve the best scientific interpretation of the data from these and future spectroscopic missions and related ground-based observations, theoretical calculations and plasma models must be verified or modified by the results obtained from measurements in the laboratory. Such measurements are the focus of several laboratory astrophysics programs that use an electron beam ion trap (EBIT) to simulate astrophysical plasma conditions. Here we describe our recent spectroscopic measurements of neon-like iron and nickel using a microcalorimeter on the EBIT at the National Institute of Standards (NIST). We obtain values for the intensity ratios of the well-known lines emitted by these ions and compare the results with new large scale electron-ion scattering calculations. Additional details about our laboratory astrophysics work can be found in some earlier papers

  8. Building a Graphite Calorimetry System for the Dosimetry of Therapeutic X-ray Beams

    Directory of Open Access Journals (Sweden)

    In Jung Kim

    2017-06-01

    Full Text Available A graphite calorimetry system was built and tested under irradiation. The noise level of the temperature measurement system was approximately 0.08 mK (peak to peak. The temperature of the core part rose by approximately 8.6 mK at 800 MU (monitor unit for 6-MV X-ray beams, and it increased as X-ray energy increased. The temperature rise showed less spread when it was normalized to the accumulated charge, as measured by an external monitoring chamber. The radiation energy absorbed by the core part was determined to have values of 0.798 J/μC, 0.389 J/μC, and 0.352 J/μC at 6 MV, 10 MV, and 18 MV, respectively. These values were so consistent among repeated runs that their coefficient of variance was less than 0.15%.

  9. X-Ray and electron beam source characterization from Self-Modulated Laser Wakefield Acceleration experiments at Titan

    Science.gov (United States)

    King, Paul; Lemos, Nuno; Albert, Felicie; Shaw, Jessica; Milder, Avi; Marsh, Ken; Pak, Art; Hegelich, Bjorn; Joshi, Chan

    2017-10-01

    The development of a directional, low-divergence, and short-duration (ps and sub-ps) x-ray probes with energies of tens of keV is desirable for the fields of astrophysics, High Energy Density Science and Inertial Confinement Fusion. In this work we focused the Titan laser beam (1 ps and 150 Joules) into a 4mm helium gas jet to produce an electron beam that in turn generates an x-ray beam. The measured Raman Forward Scattering satellites present in the laser spectrum after the interaction, indicate the generation of a Self-modulated laser wakefield accelerator. This accelerator produced an electron beam with energies up to 250 MeV, a divergence of 16 x 40 mrad and a total charge of 6 nC. Using this high-charge relativistic electron beam we explored the combination of three mechanisms to produce an x-ray beam: Betatron, Compton scattering and Bremsstrahlung. We show the generation of a low divergence (mrad), small source size (um) broadband (keV to MeV) x-ray beam that can be used as a backlighter for time-resolved spectroscopy, imaging, and Compton radiography. Work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under contract DE-AC52-07NA27344. [LLNL-ABS-734746].

  10. Characterization of the 46.9-nm soft X-ray laser beam from a capillary discharge

    Science.gov (United States)

    Barnwal, S.; Prasad, Y. B. S. R.; Nigam, S.; Aneesh, K.; Sharma, M. L.; Kushwaha, R. P.; Tripathi, P. K.; Naik, P. A.; Chakera, J. A.; Navathe, C. P.; Gupta, P. D.

    2014-10-01

    Intense lasing had been obtained from argon plasma in the soft X-ray region from a capillary discharge plasma system. Different diagnostics have been used to characterize the lasing properties by recording the temporal, spatial, and spectral profiles of the emission. The divergence measurement indicates that the soft X-ray laser beam has good directionality with a divergence of 3.5 mrad. The spectrum of the laser beam measured using a transmission grating showed intense lasing line at 46.9 nm. Diffraction orders as high as 10th orders were observed. The temporal profile recorded with a vacuum diode showed a distinct laser peak with a pulse width ~1.2 ns (FWHM). In addition, the coherence of the X-ray laser beam was also confirmed from the high-contrast interference fringes (visibility ~85 %) recorded using double slits.

  11. Simulations of x-ray speckle-based dark-field and phase-contrast imaging with a polychromatic beam

    Energy Technology Data Exchange (ETDEWEB)

    Zdora, Marie-Christine, E-mail: marie-christine.zdora@diamond.ac.uk [Lehrstuhl für Biomedizinische Physik, Physik-Department & Institut für Medizintechnik, Technische Universität München, 85748 Garching (Germany); Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE (United Kingdom); Department of Physics & Astronomy, University College London, London WC1E 6BT (United Kingdom); Thibault, Pierre [Department of Physics & Astronomy, University College London, London WC1E 6BT (United Kingdom); Pfeiffer, Franz [Lehrstuhl für Biomedizinische Physik, Physik-Department & Institut für Medizintechnik, Technische Universität München, 85748 Garching (Germany); Zanette, Irene [Lehrstuhl für Biomedizinische Physik, Physik-Department & Institut für Medizintechnik, Technische Universität München, 85748 Garching (Germany); Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE (United Kingdom)

    2015-09-21

    Following the first experimental demonstration of x-ray speckle-based multimodal imaging using a polychromatic beam [I. Zanette et al., Phys. Rev. Lett. 112(25), 253903 (2014)], we present a simulation study on the effects of a polychromatic x-ray spectrum on the performance of this technique. We observe that the contrast of the near-field speckles is only mildly influenced by the bandwidth of the energy spectrum. Moreover, using a homogeneous object with simple geometry, we characterize the beam hardening artifacts in the reconstructed transmission and refraction angle images, and we describe how the beam hardening also affects the dark-field signal provided by speckle tracking. This study is particularly important for further implementations and developments of coherent speckle-based techniques at laboratory x-ray sources.

  12. X-ray beam hardening correction for measuring density in linear accelerator industrial computed tomography

    International Nuclear Information System (INIS)

    Zhou Rifeng; Wang Jue; Chen Weimin

    2009-01-01

    Due to X-ray attenuation being approximately proportional to material density, it is possible to measure the inner density through Industrial Computed Tomography (ICT) images accurately. In practice, however, a number of factors including the non-linear effects of beam hardening and diffuse scattered radiation complicate the quantitative measurement of density variations in materials. This paper is based on the linearization method of beam hardening correction, and uses polynomial fitting coefficient which is obtained by the curvature of iron polychromatic beam data to fit other materials. Through theoretical deduction, the paper proves that the density measure error is less than 2% if using pre-filters to make the spectrum of linear accelerator range mainly 0.3 MeV to 3 MeV. Experiment had been set up at an ICT system with a 9 MeV electron linear accelerator. The result is satisfactory. This technique makes the beam hardening correction easy and simple, and it is valuable for measuring the ICT density and making use of the CT images to recognize materials. (authors)

  13. X-ray tube

    International Nuclear Information System (INIS)

    Mayo, B.J.

    1980-01-01

    An x-ray tube in which the x-ray origin is scanned on a circle around the patient, comprises a ring-shaped anode, an electron beam travelling along a circular path being deflected onto the anode at the desired positions. The electron beam path may be in a plane parallel to the anode and perhaps at the same radius. It may be in the same plane as a transmission target/anode and at a greater radius. The anode should extend over at least 180 0 although it may extend to 360 0 . Electrostatic means may be provided to constrain the beam to the circular path and further electrostatic means deflect it to the anode of the beam and ensure it is focused at the point of incidence. Collimators provide a planar fan-shaped beam and the anode may be shaped to attenuate side lobes of the radiation. Electrode collects electrons not deflected. The focal regions may be adjacent or otherwise. Coils may provide periodic focusing to overcome space charge dispersion and dynamic adjustment of the focusing before deflection ensures focusing at target incidence. Focusing may be absent near the deflection region, and current in the coil section near the focal region should be zero. (author)

  14. The influence of an extrapolation chamber over the low energy X-ray beam radiation field

    Energy Technology Data Exchange (ETDEWEB)

    Tanuri de F, M. T.; Da Silva, T. A., E-mail: mttf@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear / CNEN, Av. Pte. Antonio Carlos 6627, 31270-901 Pampulha, Belo Horizonte, Minas Gerais (Brazil)

    2016-10-15

    The extrapolation chambers are detectors whose sensitive volume can be modified by changing the distance between the electrodes and has been widely used for beta particles primary measurement system. In this work, was performed a PTW 23392 extrapolation chamber Monte Carlo simulation, by mean the MCNPX code. Although the sensitive volume of an extrapolation chamber can be reduced to very small size, their packaging is large enough to modify the radiation field and change the absorbed dose measurements values. Experiments were performed to calculate correction factors for this purpose. The validation of the Monte Carlo model was done by comparing the spectra obtained with a CdTe detector according to the ISO 4037 criteria. Agreements smaller than 5% for half value layers, 10% for spectral resolution and 1% for mean energy, were found. It was verified that the correction factors are dependent of the X-ray beam quality. (Author)

  15. X-ray Tomography Characterisation of Lattice Structures Processed by Selective Electron Beam Melting

    Directory of Open Access Journals (Sweden)

    Everth Hernández-Nava

    2017-08-01

    Full Text Available Metallic lattice structures intentionally contain open porosity; however, they can also contain unwanted closed porosity within the structural members. The entrained porosity and defects within three different geometries of Ti-6Al-4V lattices, fabricated by Selective Electron Beam Melting (SEBM, is assessed from X-ray computed tomography (CT scans. The results suggest that horizontal struts that are built upon loose powder show particularly high (~20 × 10−3 vol % levels of pores, as do nodes at which many (in our case 24 struts meet. On the other hand, for struts more closely aligned (0° to 54° to the build direction, the fraction of porosity appears to be much lower (~0.17 × 10−3% arising mainly from pores contained within the original atomised powder particles.

  16. Evaluation of a tissue equivalent ionization chamber in X-ray beams

    International Nuclear Information System (INIS)

    Perini, Ana Paula; Neves, Lucio Pereira; Santos, William de Souza; Caldas, Linda V.E.; Frimaio, Audrew; Costa, Paulo R.

    2014-01-01

    Tissue equivalent materials present a variety of uses, including routine quality assurance and quality control programs in both diagnostic and therapeutic physics. They are frequently used in research facilities to measure doses delivered to patients undergoing various clinical procedures. This work presents the development and evaluation of a tissue equivalent ionization chamber, with a sensitive volume of 2.3 cm 3 , for routine use in X-rays beams. This ionization chamber was developed at the Calibration Laboratory/IPEN. The new tissue equivalent material was developed at the Physics Institute of the University of Sao Paulo. In order to evaluate the dosimetric performance of the new ionization chamber, several tests described by international standards were undertaken, and all results were within the recommended limits. (author)

  17. Fresnel zone plate with apodized aperture for hard X-ray Gaussian beam optics.

    Science.gov (United States)

    Takeuchi, Akihisa; Uesugi, Kentaro; Suzuki, Yoshio; Itabashi, Seiichi; Oda, Masatoshi

    2017-05-01

    Fresnel zone plates with apodized apertures [apodization FZPs (A-FZPs)] have been developed to realise Gaussian beam optics in the hard X-ray region. The designed zone depth of A-FZPs gradually decreases from the center to peripheral regions. Such a zone structure forms a Gaussian-like smooth-shouldered aperture function which optically behaves as an apodization filter and produces a Gaussian-like focusing spot profile. Optical properties of two types of A-FZP, i.e. a circular type and a one-dimensional type, have been evaluated by using a microbeam knife-edge scan test, and have been carefully compared with those of normal FZP optics. Advantages of using A-FZPs are introduced.

  18. Automated three-dimensional X-ray analysis using a dual-beam FIB

    International Nuclear Information System (INIS)

    Schaffer, Miroslava; Wagner, Julian; Schaffer, Bernhard; Schmied, Mario; Mulders, Hans

    2007-01-01

    We present a fully automated method for three-dimensional (3D) elemental analysis demonstrated using a ceramic sample of chemistry (Ca)MgTiO x . The specimen is serially sectioned by a focused ion beam (FIB) microscope, and energy-dispersive X-ray spectrometry (EDXS) is used for elemental analysis of each cross-section created. A 3D elemental model is reconstructed from the stack of two-dimensional (2D) data. This work concentrates on issues arising from process automation, the large sample volume of approximately 17x17x10 μm 3 , and the insulating nature of the specimen. A new routine for post-acquisition data correction of different drift effects is demonstrated. Furthermore, it is shown that EDXS data may be erroneous for specimens containing voids, and that back-scattered electron images have to be used to correct for these errors

  19. Reproducibility assessment of commercial optically stimulated luminescence system in diagnostic X-ray beams

    International Nuclear Information System (INIS)

    Yahaya Musa; Bradley, D.A.; Sunway University, Selangor; Karim, M.K.A.; Asmaliza Hashim

    2017-01-01

    This study investigates the reproducibility of commercial optically stimulated luminescence (OSL) system at different X-ray beams in general radiography. The reader stability was evaluated at first and found to be within the accepted tolerance level of ± 10%. Henceforth, reproducibility of OSL dosimeters due to repeated readouts after single exposure were found to be between 1.0% (80 kV/20 mGy) and 5.9% (80 kV/10 mAs), while reproducibility in repeated irradiation of optically stimulated luminescence dosimeters (OSLDs) from the same batch (80 kV/8 mGy) was between 1.8 and 4.3%. After multiple readouts of OSLD, the OSL signal decreased by approximately - 0.4% per readout and - 5.4% per 10 sequential readouts. The reproducibility response demonstrates the suitability of the nanoDots OSLD for use in radiography. (author)

  20. The influence of an extrapolation chamber over the low energy X-ray beam radiation field

    International Nuclear Information System (INIS)

    Tanuri de F, M. T.; Da Silva, T. A.

    2016-10-01

    The extrapolation chambers are detectors whose sensitive volume can be modified by changing the distance between the electrodes and has been widely used for beta particles primary measurement system. In this work, was performed a PTW 23392 extrapolation chamber Monte Carlo simulation, by mean the MCNPX code. Although the sensitive volume of an extrapolation chamber can be reduced to very small size, their packaging is large enough to modify the radiation field and change the absorbed dose measurements values. Experiments were performed to calculate correction factors for this purpose. The validation of the Monte Carlo model was done by comparing the spectra obtained with a CdTe detector according to the ISO 4037 criteria. Agreements smaller than 5% for half value layers, 10% for spectral resolution and 1% for mean energy, were found. It was verified that the correction factors are dependent of the X-ray beam quality. (Author)

  1. Determination of the interest volume of a primary standard for lows energy X-ray beams

    International Nuclear Information System (INIS)

    Cardoso, Ricardo de Souza; Bossio, Francisco; Peixoto, Jose Guilherme

    2005-01-01

    The technical drawing represents the indispensable link between various branches of industrial enterprises. Is necessary for the drawing clear representation of the different pieces, with the marks of all requirements of machining and finish, with the intention that the workmen with low performance make the build drawn. Is a complete graphical language that describes each operation and guard the register of the piece and turn available the reproduction and repair of the piece. The present work had the aim to determine the interest volume of the ionization chamber of variable volume manufactured by Victoreen Instruments, model 481, introduced in LNMRI/IRD to establish the quantity air Kerma from beam X rays of low energy. (author)

  2. Calibration of the Gamma-RAy Polarimeter Experiment (GRAPE) at a polarized hard X-ray beam

    International Nuclear Information System (INIS)

    Bloser, P.F.; Legere, J.S.; McConnell, M.L.; Macri, J.R.; Bancroft, C.M.; Connor, T.P.; Ryan, J.M.

    2009-01-01

    The Gamma-RAy Polarimeter Experiment (GRAPE) is a concept for an astronomical hard X-ray Compton polarimeter operating in the 50-500 keV energy band. The instrument has been optimized for wide-field polarization measurements of transient outbursts from energetic astrophysical objects such as gamma-ray bursts and solar flares. The GRAPE instrument is composed of identical modules, each of which consists of an array of scintillator elements read out by a multi-anode photomultiplier tube (MAPMT). Incident photons Compton scatter in plastic scintillator elements and are subsequently absorbed in inorganic scintillator elements; a net polarization signal is revealed by a characteristic asymmetry in the azimuthal scattering angles. We have constructed a prototype GRAPE module containing a single CsI(Na) calorimeter element, at the center of the MAPMT, surrounded by 60 plastic elements. The prototype has been combined with custom readout electronics and software to create a complete 'engineering model' of the GRAPE instrument. This engineering model has been calibrated using a nearly 100% polarized hard X-ray beam at the Advanced Photon Source at Argonne National Laboratory. We find modulation factors of 0.46±0.06 and 0.48±0.03 at 69.5 and 129.5 keV, respectively, in good agreement with Monte Carlo simulations. In this paper we present details of the beam test, data analysis, and simulations, and discuss the implications of our results for the further development of the GRAPE concept.

  3. 'Six-beam X-ray section topograph' images and computer-simulated images using the new n-beam dynamical theory based on the Takagi-Taupin equations.

    Science.gov (United States)

    Okitsu, Kouhei; Imai, Yasuhiko; Ueji, Yoshinori; Yoda, Yoshitaka

    2003-07-01

    A 'six-beam X-ray section topograph' experiment was performed whose images are in excellent agreement with the images computer-simulated using the theory derived by one of the authors [Okitsu (2003). Acta Cryst. A59, 235-244] based on the Takagi-Taupin dynamical theory. X-rays whose wavefront was limited to 0.1 x 0.1 mm were incident on a [1 1; 1]-oriented floating-zone silicon crystal with thickness of 9.911 mm so that a six-beam condition was satisfied. The six reflection indices were 000 (forward diffraction), 440, 484, 088, 4;48 and 4;04. The plane of incidence of the 088 reflection was adjusted so as to be perpendicular to the direction of the incident horizontal linear polarization of the synchrotron radiation, which was monochromated into 18.5 keV (0.670 A wavelength). While the simulations were performed under the assumptions that the incident X-rays were linearly polarized both horizontally and vertically, they were evidently different and only the simulated images under the assumption of horizontally polarized incident X-rays were in excellent agreement with the images obtained by the experiment.

  4. Dosimetry of x-ray beams: The measure of the problem

    International Nuclear Information System (INIS)

    de Castro, T.M.

    1986-08-01

    This document contains the text of an oral presentation on dosimetry of analytical x-ray equipment presented at the Denver X-Ray Conference. Included are discussions of sources of background radiation, exposure limits from occupational sources, and the relationship of these sources to the high dose source of x-rays found in analytical machines. The mathematical basis of x-ray dosimetry is reviewed in preparation for more detailed notes on personnel dosimetry and the selection of the most appropriate dosimeter for a specific application. The presentation concludes with a discussion common to previous x-ray equipment accidents. 2 refs

  5. X-ray beam-shaping via deformable mirrors: Analytical computation of the required mirror profile

    Energy Technology Data Exchange (ETDEWEB)

    Spiga, Daniele, E-mail: daniele.spiga@brera.inaf.it [INAF/Osservatorio Astronomico di Brera, Via E. Bianchi 46, I-23807, Merate (Italy); Raimondi, Lorenzo; Svetina, Cristian [Sincrotrone Trieste ScpA, S.S. 14 km 163.5 in Area Science Park, 34149 Trieste (Italy); Zangrando, Marco [Sincrotrone Trieste ScpA, S.S. 14 km 163.5 in Area Science Park, 34149 Trieste (Italy); IOM-CNR, S.S. 14 km 163.5 in Area Science Park, 34149 Trieste (Italy)

    2013-05-11

    X-ray mirrors with high focusing performances are in use in both mirror modules for X-ray telescopes and in synchrotron and FEL (Free Electron Laser) beamlines. A degradation of the focus sharpness arises in general from geometrical deformations and surface roughness, the former usually described by geometrical optics and the latter by physical optics. In general, technological developments are aimed at a very tight focusing, which requires the mirror profile to comply with the nominal shape as much as possible and to keep the roughness at a negligible level. However, a deliberate deformation of the mirror can be made to endow the focus with a desired size and distribution, via piezo actuators as done at the EIS-TIMEX beamline of FERMI@Elettra. The resulting profile can be characterized with a Long Trace Profilometer and correlated with the expected optical quality via a wavefront propagation code. However, if the roughness contribution can be neglected, the computation can be performed via a ray-tracing routine, and, under opportune assumptions, the focal spot profile (the Point Spread Function, PSF) can even be predicted analytically. The advantage of this approach is that the analytical relation can be reversed; i.e., from the desired PSF the required mirror profile can be computed easily, thereby avoiding the use of complex and time-consuming numerical codes. The method can also be suited in the case of spatially inhomogeneous beam intensities, as commonly experienced at synchrotrons and FELs. In this work we expose the analytical method and the application to the beam shaping problem.

  6. X-ray beam-shaping via deformable mirrors: Analytical computation of the required mirror profile

    International Nuclear Information System (INIS)

    Spiga, Daniele; Raimondi, Lorenzo; Svetina, Cristian; Zangrando, Marco

    2013-01-01

    X-ray mirrors with high focusing performances are in use in both mirror modules for X-ray telescopes and in synchrotron and FEL (Free Electron Laser) beamlines. A degradation of the focus sharpness arises in general from geometrical deformations and surface roughness, the former usually described by geometrical optics and the latter by physical optics. In general, technological developments are aimed at a very tight focusing, which requires the mirror profile to comply with the nominal shape as much as possible and to keep the roughness at a negligible level. However, a deliberate deformation of the mirror can be made to endow the focus with a desired size and distribution, via piezo actuators as done at the EIS-TIMEX beamline of FERMI@Elettra. The resulting profile can be characterized with a Long Trace Profilometer and correlated with the expected optical quality via a wavefront propagation code. However, if the roughness contribution can be neglected, the computation can be performed via a ray-tracing routine, and, under opportune assumptions, the focal spot profile (the Point Spread Function, PSF) can even be predicted analytically. The advantage of this approach is that the analytical relation can be reversed; i.e., from the desired PSF the required mirror profile can be computed easily, thereby avoiding the use of complex and time-consuming numerical codes. The method can also be suited in the case of spatially inhomogeneous beam intensities, as commonly experienced at synchrotrons and FELs. In this work we expose the analytical method and the application to the beam shaping problem

  7. Characteristic parameters analysis on diagnostic X-ray beams for dosemeter calibration

    International Nuclear Information System (INIS)

    Oliveira, Paulo Marcio Campos de

    2008-01-01

    Ionizing radiation metrology is the base to achieve reliable dose measurements in ali areas; it is also part of the framework that is established to assure radiation protection procedures in order to avoid or minimize the harmful biological effect that may be caused by ionizing radiation. A well done metrology means the use of reliable instruments that comply with standard performance requirements worldwide accepted. Those instruments are expected to be calibrated by Metrology Laboratories under well defined conditions. The International Electrotechnical Commission (IEC) in Standard 61267 established the reference radiations for medical diagnostic x-ray equipment that are recommended to be used for calibrating dosimetric systems for diagnostic dosimetry. In this work, X-ray beam qualities were established in a Calibration Laboratory and their characteristics were analyzed through the measurement of beam parameters like inherent tube filtration, beam uniformity and field size, energy spectra and peak voltage for additional filtration with 94.425 por cent and 99.999 por cent purity filters. Also, the first half-value layer and the homogeneity coefficient were measured for the three RQR 2, RQR 6 and RQR 10 IEC beam qualities and they were analyzed according to the IEC standard. Air-kerma measurements were carried out with an ionization chamber that had its reliability confirmed through repetition and reproducibility reading tests. In 50 sets of measurements the maximum standard deviation found of 10 successive readings was 0.19 %; the maximum shift of the reading mean value at a fixed geometry condition was 0.80 % with an overall standard deviation of 0.23 %. Results showed that the use of different purity filters did not cause a relevant influence on the beam energy spectra. An ionization chamber was also calibrated against a standard dosimeter in ali implemented reference radiations and the relevant sources of uncertainties were estimated. Calibration could be done

  8. Marshall Grazing Incidence X-ray Spectrometer (MaGIXS) Slit-Jaw Imaging System

    Science.gov (United States)

    Wilkerson, P.; Champey, P. R.; Winebarger, A. R.; Kobayashi, K.; Savage, S. L.

    2017-12-01

    The Marshall Grazing Incidence X-ray Spectrometer is a NASA sounding rocket payload providing a 0.6 - 2.5 nm spectrum with unprecedented spatial and spectral resolution. The instrument is comprised of a novel optical design, featuring a Wolter1 grazing incidence telescope, which produces a focused solar image on a slit plate, an identical pair of stigmatic optics, a planar diffraction grating and a low-noise detector. When MaGIXS flies on a suborbital launch in 2019, a slit-jaw camera system will reimage the focal plane of the telescope providing a reference for pointing the telescope on the solar disk and aligning the data to supporting observations from satellites and other rockets. The telescope focuses the X-ray and EUV image of the sun onto a plate covered with a phosphor coating that absorbs EUV photons, which then fluoresces in visible light. This 10-week REU project was aimed at optimizing an off-axis mounted camera with 600-line resolution NTSC video for extremely low light imaging of the slit plate. Radiometric calculations indicate an intensity of less than 1 lux at the slit jaw plane, which set the requirement for camera sensitivity. We selected a Watec 910DB EIA charge-coupled device (CCD) monochrome camera, which has a manufacturer quoted sensitivity of 0.0001 lux at F1.2. A high magnification and low distortion lens was then identified to image the slit jaw plane from a distance of approximately 10 cm. With the selected CCD camera, tests show that at extreme low-light levels, we achieve a higher resolution than expected, with only a moderate drop in frame rate. Based on sounding rocket flight heritage, the launch vehicle attitude control system is known to stabilize the instrument pointing such that jitter does not degrade video quality for context imaging. Future steps towards implementation of the imaging system will include ruggedizing the flight camera housing and mounting the selected camera and lens combination to the instrument structure.

  9. Estimation of effective dose from limited cone beam X-ray CT examination

    Energy Technology Data Exchange (ETDEWEB)

    Iwai, Kazuo; Arai, Yoshinori; Hashimoto, Koji [Nihon Univ., Tokyo (Japan). School of Dentistry; Nishizawa, Kanae

    2000-12-01

    The limited cone beam X-ray CT (Ortho-CT) was developed on the basis of multi-functional panoramic apparatus, SCANORA (Soredex Co. Helsinki Finland). The imaging intensifier (I.I.) was built in this apparatus as a X-ray detection device instead of X-ray film. The signal provided from I.I. was converted from analog into digital by an analog-digital converter and image reconstitution was done as a three-directional image of the dimensions 3.8 cm of width, 3.0 cm height and 3.8 cm depth with the personal computer. The 3DX Multi image micro CT'' (3DX) was developed along similar lines by MORITA Co., Ltd. (Kyoto, JAPAN). In this study, the stochastic effect on organ and tissue caused by examinations using Ortho-CT and 3DX was measured. The effective dose was estimated according to the recommendation of ICRP60 and was compared with those of panoramic radiography and computed tomography. The irradiation conditions were as follows: 85 kV, 10 mA with the filtration of 3 mmAl and added 1 mmCu for Ortho-CT, and 80 kV, 2 mA and the filtration of 3.1 mmAL for 3DX. The measurement of organ and tissue dose was performed using an anthropomorphic Rando woman phantom (Alderson Research Laboratories Co., Stanfora, CN), as well as by using two different type of thermoluminescent dosimeter (TLD); Panasonic UD-170A (BeO) and UD-110S (CaSO{sub 4}: Tm). The UD-170A was for dose measurement of the inner useful X-ray beams, while the UD-110S was for outer beams. The measured organ and tissue were those recommended with ICRP60 (gonad, breast, bone marrow, lung, thyroid gland, esophagus, stomach, colon, liver, bladder, skin, brain, thymus, adrenal, kidney, spleen, pancrease, upper large intestine, uterus, eyes and major salivary gland). The imaging by Orhto-CT was made in the left maxillary 1st molar, left mandibular 1st molar and temporomandibular joint. 3DX measurement was made in the maxillary incisor region and middle ear regions other than the regions mentioned above. The skin

  10. X-ray beam design for multi-energy imaging with charge-integrating detector: A simulation study

    Energy Technology Data Exchange (ETDEWEB)

    Baek, Cheol-Ha [Department of Radiological Science, Dongseo University, 47 Jurye-ro, Sasang, Busan 617-716 (Korea, Republic of); Center for Radiological Environment & Health Science, Dongseo University, 47 Jurye-ro, Sasang, Busan 617-716 (Korea, Republic of); Kim, Daehong, E-mail: goldcollar011@gmail.com [Department of Radiological Science, Eulji University, 553 Sanseong-daero, Seongnam 461-713, Gyeonggi-do (Korea, Republic of)

    2015-11-01

    Multi-energy X-ray imaging systems have been widely used for clinical examinations. In order to enhance the imaging quality of these X-ray systems, a dual-energy system that can obtain specific information has been developed in order to discriminate different materials. Although the dual-energy system shows reliable performance for clinical applications, it is necessary to improve the method in order to minimize radiation dose, reduce projection error, and increase image contrast. The purpose of this study is to develop a triple energy technique that can discriminate three materials for the purpose of enhancing imaging quality and patient safety. The X-ray system tube voltage was varied from 40 to 90 kV, and filters (that can generate three X-ray energies) were installed, consisting of pure elemental materials in foil form (including Al, Cu, I, Ba, Ce, Gd, Er, and W). The X-ray beam was evaluated with respect to mean energy ratio, contrast variation ratio, and exposure efficiency. In order to estimate the performance of the suggested technique, Monte Carlo was conducted, and the results were compared to the photon-counting method. As a result, the density maps of iodine, aluminum, and polymethyl methacrylate (PMMA) using the X-ray beam were more accurate in comparison to that obtained with the photon-counting method. According to the results, the suggested triple energy technique can improve the accuracy of the determination of thickness of density. Moreover, the X-ray beam could reduce unnecessary patient dose.

  11. X-ray diffraction imaging of material microstructures

    KAUST Repository

    Varga, Laszlo

    2016-10-20

    Various examples are provided for x-ray imaging of the microstructure of materials. In one example, a system for non-destructive material testing includes an x-ray source configured to generate a beam spot on a test item; a grid detector configured to receive x- rays diffracted from the test object; and a computing device configured to determine a microstructure image based at least in part upon a diffraction pattern of the x-rays diffracted from the test object. In another example, a method for determining a microstructure of a material includes illuminating a beam spot on the material with a beam of incident x-rays; detecting, with a grid detector, x-rays diffracted from the material; and determining, by a computing device, a microstructure image based at least in part upon a diffraction pattern of the x-rays diffracted from the material.

  12. Multi-mounted X-ray cone-beam computed tomography

    Science.gov (United States)

    Fu, Jian; Wang, Jingzheng; Guo, Wei; Peng, Peng

    2018-04-01

    As a powerful nondestructive inspection technique, X-ray computed tomography (X-CT) has been widely applied to clinical diagnosis, industrial production and cutting-edge research. Imaging efficiency is currently one of the major obstacles for the applications of X-CT. In this paper, a multi-mounted three dimensional cone-beam X-CT (MM-CBCT) method is reported. It consists of a novel multi-mounted cone-beam scanning geometry and the corresponding three dimensional statistical iterative reconstruction algorithm. The scanning geometry is the most iconic design and significantly different from the current CBCT systems. Permitting the cone-beam scanning of multiple objects simultaneously, the proposed approach has the potential to achieve an imaging efficiency orders of magnitude greater than the conventional methods. Although multiple objects can be also bundled together and scanned simultaneously by the conventional CBCT methods, it will lead to the increased penetration thickness and signal crosstalk. In contrast, MM-CBCT avoids substantially these problems. This work comprises a numerical study of the method and its experimental verification using a dataset measured with a developed MM-CBCT prototype system. This technique will provide a possible solution for the CT inspection in a large scale.

  13. High resolution simulation of beam dynamics in electron linacs for x-ray free electron lasers

    Directory of Open Access Journals (Sweden)

    J. Qiang

    2009-10-01

    Full Text Available In this paper we report on large-scale high resolution simulations of beam dynamics in electron linacs for the next-generation x-ray free electron lasers (FELs. We describe key features of a parallel macroparticle simulation code including three-dimensional (3D space-charge effects, short-range structure wakefields, coherent synchrotron radiation (CSR wakefields, and treatment of radio-frequency (rf accelerating cavities using maps obtained from axial field profiles. We present a study of the microbunching instability causing severe electron beam fragmentation in the longitudinal phase space which is a critical issue for future FELs. Using parameters for a proposed FEL linac at Lawrence Berkeley National Laboratory (LBNL, we show that a large number of macroparticles (beyond 100 million is generally needed to control the numerical macroparticle shot noise and avoid overestimating the microbunching instability. We explore the effect of the longitudinal grid on simulation results. We also study the effect of initial uncorrelated energy spread on the final uncorrelated energy spread of the beam for the FEL linac.

  14. On the determination of stress profiles in expanded austenite by grazing incidence X-ray diffraction and successive layer removal

    DEFF Research Database (Denmark)

    Fernandes, Frederico Augusto Pires; Christiansen, Thomas L.; Winther, Grethe

    2015-01-01

    Surface layers of expanded austenite resulting from nitriding typically exhibit large gradients in residual stress and composition. Evaluation of residual-stress profiles is explored by means of grazing incidence X-ray diffraction (GI-XRD), probing shallow depths, combined with successive layer...

  15. Multiple scattering in grazing-incidence X-ray diffraction : Impact on lattice-constant determination in thin films

    NARCIS (Netherlands)

    Resel, Roland; Bainschab, Markus; Pichler, Alexander; Dingemans, T.J.; Simbrunner, Clemens; Stangl, Julian; Salzmann, Ingo

    2016-01-01

    Dynamical scattering effects are observed in grazing-incidence X-ray diffraction experiments using an organic thin film of 2,2′:6′,2′′-ternaphthalene grown on oxidized silicon as substrate. Here, a splitting of all Bragg peaks in the out-of-plane direction (z-direction) has been observed, the

  16. X-ray study of a test quadrant of the SODART telescopes using the expanded beam x-ray optics facility at the Daresbury synchrotron

    DEFF Research Database (Denmark)

    Christensen, Finn Erland; Hornstrup, Allan; Frederiksen, P.

    1994-01-01

    The imaging properties of a test model of the SODART telescopes have been studied using an expanded beam X-ray facility at the Daresbury synchrotron. The encircled power and the point spread function at three energies 6.627 keV, 8.837 keV and 11.046 keV have been measured using 1D and 2D position......V the HPD is 2.5 - 3.0 arcmin for all detectors whereas it is somewhat larger at 11.046 keV for HEPC and LEPC but essentially unchanged for SIXA. Finally, the data are used to point to improvements that can be introduced during the manufacture of the flight telescopes....

  17. X-ray study of a SODART flight telescope using the expanded beam x-ray optics beamline at the Daresbury synchrotron

    DEFF Research Database (Denmark)

    Christensen, Finn Erland; Hornstrup, Allan; Frederiksen, P. K.

    1995-01-01

    The on- and off-axis imaging properties of the first of two SODART flight telescopes have been studied using the expanded beam x-ray facility at the Daresbury synchrotron. From on- axis measurements the encircled power distribution and the point spread function at three energies 6.627 keV, 8.837 ke...... element solid state array detector (SIXA). We found that the HPD decreases with increasing energy due to poorer figure error of the outermost mirrors. The HPD falls in the range from 2.3 to 3 arcmin for all detectors. Residual misalignment of the individual quadrants of the telescope was found...... to contribute to the HPD by approximately 10%. If 33% of the geometric telescope area near the edges of the quadrants are covered a reduction of 10% of the HPD can be obtained. On- and off-axis images generated from the one dimensional intensity distribution are presented. Finally the data have been used...

  18. Accuracy validation of incident photon fluence on DQE for various measurement conditions and X-ray units.

    Science.gov (United States)

    Haba, Tomonobu; Kondo, Shimpei; Hayashi, Daiki; Koyama, Shuji

    2013-07-01

    Detective quantum efficiency (DQE) is widely used as a comprehensive metric for X-ray image evaluation in digital X-ray units. The incident photon fluence per air kerma (SNR²(in)) is necessary for calculating the DQE. The International Electrotechnical Commission (IEC) reports the SNR²(in) under conditions of standard radiation quality, but this SNR²(in) might not be accurate as calculated from the X-ray spectra emitted by an actual X-ray tube. In this study, we evaluated the error range of the SNR²(in) presented by the IEC62220-1 report. We measured the X-ray spectra emitted by an X-ray tube under conditions of standard radiation quality of RQA5. The spectral photon fluence at each energy bin was multiplied by the photon energy and the mass energy absorption coefficient of air; then the air kerma spectrum was derived. The air kerma spectrum was integrated over the whole photon energy range to yield the total air kerma. The total photon number was then divided by the total air kerma. This value is the SNR²(in). These calculations were performed for various measurement parameters and X-ray units. The percent difference between the calculated value and the standard value of RQA5 was up to 2.9%. The error range was not negligibly small. Therefore, it is better to use the new SNR²(in) of 30694 (1/(mm(2) μGy)) than the current [Formula: see text] of 30174 (1/(mm(2) μGy)).

  19. Comparison of the effect of X-ray and electron beam irradiation on the thiamine content in chicken drumsticks

    International Nuclear Information System (INIS)

    Calenberg, S. van; Cleemput, O. van; Huyghebaert, A.; Mondelaers, W.

    1998-01-01

    The effect of irradiation with X-rays and electron beams on the thiamine content of chicken drumsticks in function of the storage time at refrigerator temperature was examined. A measurement of the total colony count was used as an indication of the preservation time. The irradiation dose applied ranged from 0 to 7 kGy at dose rates of 0.05 and 5 kGy/min for X-rays and electron beams respectively. It was concluded that differences in the thiamine breakdown between the two types of irradiation increased as the dose increased. In the worst case, at the X-ray treatment of 7 kGy, the mean loss in thiamine was 46.06%

  20. Modelling properties of hard x-rays generated by the interaction between relativistic electrons and very intense laser beams

    International Nuclear Information System (INIS)

    Popa, Alexandru

    2009-01-01

    In a previous paper we presented a calculation model for high harmonic generation by relativistic Thomson scattering of the electromagnetic radiation by free electrons. In this paper we present a similar model for the calculation of the energies of hard x-rays (20- 200 keV) resulted from the interaction between relativistic electrons (20-100 MeV) and very intense laser beams. Starting from the relativistic equations of motion of an electron in the electromagnetic field we show that the Lienard-Wiechert equation leads to electromagnetic waves whose frequencies are in the domain of hard x-rays. When the relativistic parameter of the laser beam is greater than unity, the model predicts the existence of harmonics of the above frequencies. Our theoretical values are in good agreement with experimental values of the x-ray energies from the literature and predict accurately their angular distribution.

  1. Development of a PIXE (Particle Induced X-ray Emission) analysis device using an extracted proton beam

    International Nuclear Information System (INIS)

    Saidi, A.

    1989-01-01

    The experimental device described allows the extention of the PIXE (Particle Induced X-ray Emission) method to the analysis, by means of proton beams, of solid or liquid samples, which can not be analyzed under vacuum conditions. The homogeneity of the surfaces to be analysed and elements (in the atmosphere) which absorb X-rays must be taken into account. Liquid samples do not need special care. The results show that: at high energies, the extracted beam sensibility is of the same order of magnitude as those obtained under vacuum; at low energies, the performance under vacuum conditions is better. The particles energy losses, at the exit membrane and in the outer atmosphere, decrease the X-rays production efficiency [fr

  2. Numerical controlled diamond fly cutting machine for grazing incidence X-ray reflection mirrors

    International Nuclear Information System (INIS)

    Uchida, Fumihiko; Moriyama, Shigeo; Seya, Eiiti

    1992-01-01

    Synchrotron radiation has reached the stage of practical use, and the application to the wide fields that support future advanced technologies such as spectroscopy, the structural analysis of matters, semiconductor lithography and medical light source is expected. For the optical system of the equipment utilizing synchrotron radiation, the total reflection mirrors of oblique incidence are used for collimating and collecting X-ray. In order to restrain their optical aberration, nonspherical shape is required, and as the manufacturing method with high precision for nonspherical mirrors, a numerically controlled diamond cutting machine was developed. As for the cutting of soft metals with diamond tools, the high precision machining of any form can be done by numerical control, the machining time can be reduced as compared with grinding, and the cooling effect is large in metals. The construction of the cutting machine, the principle of machining, the control system, the method of calculating numerical control data, the investigation of machinable forms and the result of evaluation are reported. (K.I.)

  3. Applications of a glazing incidence X-ray fluorescence analysis to forensic samples

    International Nuclear Information System (INIS)

    Ninomiya, Toshio; Nomura, Shigeaki; Taniguchi, Kazuo; Ikeda, Shigero.

    1995-01-01

    A glazing incidence X-ray fluorescence analysis (GIXF) has been applied to forensic samples: a counterfeit 100-dollar bill, fragments of polyvinyl tapes, a trace of semen, illegal drugs, fingerprints and fake V.S.O.P brandy. Strontium could not be detected on the magnet-respondent letter of the counterfeit bill and Br was detected on the magnet-nonrespondent part of the counterfeit bill, while such phenomena could not be noticed on a true bill. Fragments of black vinyl tapes related to a sexual assault case could be discriminated from each other. Zinc as a characteristic ingredient could be detected in a trace of semen. Bromine was detected in each of what is called a pure methamphetamine crystal and K, Ca, Fe, Zn etc. were detected in heroin powders. Lead was sharply detected in gunshot residues attached to a finger after gunfiring. Sulfur as a contaminant was abundant in fake V.S.O.P brandy, while no S was detected in genuine V.S.O.P brandy. (author)

  4. Applications of a glazing incidence X-ray fluorescence analysis to forensic samples

    Energy Technology Data Exchange (ETDEWEB)

    Ninomiya, Toshio [Hyogo Prefecture, Kobe (Japan). Forensic Science Lab.; Nomura, Shigeaki; Taniguchi, Kazuo; Ikeda, Shigero

    1995-06-01

    A glazing incidence X-ray fluorescence analysis (GIXF) has been applied to forensic samples: a counterfeit 100-dollar bill, fragments of polyvinyl tapes, a trace of semen, illegal drugs, fingerprints and fake V.S.O.P brandy. Strontium could not be detected on the magnet-respondent letter of the counterfeit bill and Br was detected on the magnet-nonrespondent part of the counterfeit bill, while such phenomena could not be noticed on a true bill. Fragments of black vinyl tapes related to a sexual assault case could be discriminated from each other. Zinc as a characteristic ingredient could be detected in a trace of semen. Bromine was detected in each of what is called a pure methamphetamine crystal and K, Ca, Fe, Zn etc. were detected in heroin powders. Lead was sharply detected in gunshot residues attached to a finger after gunfiring. Sulfur as a contaminant was abundant in fake V.S.O.P brandy, while no S was detected in genuine V.S.O.P brandy. (author).

  5. Analysis of crystalline phases in airborne particulates by grazing incidence X-ray diffractometry.

    Science.gov (United States)

    Ozaki, Kana; Hanatani, Toshikazu; Nakamura, Toshihiro

    2005-07-01

    Amounts of crystalline phases of airborne particulates collected on a silicon wafer (10 x 10 mm) using a high-volume air sampler were analyzed by grazing incidence X-ray diffractometry (GIXD). Airborne particulates were classified into five size ranges (1.09-10.5 microm) with a cascade impactor attached on the sampling ports of the high-volume air sampler. GIXD was used throughout this analysis to obtain better sensitivity for small amounts of airborne particulates on the silicon wafer. Calibration standards on the silicon wafer for the diffractometric determination were prepared by the suspension droplet method of the crystalline standards dispersed in cyclohexane. Analytical lines were (020) for gypsum, (101) for quartz, (104) for calcite, (200) for halite, and (110) for sal ammoniac. The sample and the calibrating standards were heated at 350 degrees C for 2 h to avoid mutual interference with gypsum (041 and 221) when calcite and halite were determined. The GIXD method enables us to determine 0.23-13.2 microg of gypsum, quartz, calcite, halite and sal ammoniac in 0.110-0.233 mg of airborne particulates on the silicon wafer.

  6. Magnitude and effects of X-ray scatter of a cone-beam micro-CT for small animal imaging

    Energy Technology Data Exchange (ETDEWEB)

    Ni, Y.C. [Institute of Nuclear Energy Research, Longtan 32546, Taiwan (China); Jan, M.L. [Institute of Nuclear Energy Research, Longtan 32546, Taiwan (China); Chen, K.W. [Institute of Nuclear Energy Research, Longtan 32546, Taiwan (China); Cheng, Y.D. [Department of Nuclear Science, National Tsing-Hua University, Hsinchu 30043, Taiwan (China); Chuang, K.S. [Department of Nuclear Science, National Tsing-Hua University, Hsinchu 30043, Taiwan (China); Fu, Y.K. [Institute of Nuclear Energy Research, Longtan 32546, Taiwan (China)]. E-mail: fufrank@iner.gov.tw

    2006-12-20

    We have developed a micro-CT system to provide high-resolution and anatomic information to combine with a microPET'' (registered) R4 system. This study was to evaluate the magnitude and effects of scatter for low kVp X-ray in this cone-beam micro-CT system. Slit collimators were used to simulate fan-beam micro-CT for comparison. The magnitudes of X-ray scatter were measured using the beam-stop method and were estimated by polynomial-fitting extrapolation to 0 mm size of stoppers. The scatter-to-primary ratio at center of the cone-beam system were 45% and 20% for rat and mouse phantoms, respectively, and were reduced to 5.86% and 4.2% in fan-beam geometric setup. The effects of X-ray scatter on image uniformity and contrast ratio were evaluated also. The uniformity response was examined by the profile of the reconstructed image. The degrees of 'cupping' in the fan-beam and cone-beam conditions were 1.75% and 3.81%, respectively, in rat phantom. A contrast phantom consisting of four inserts with physical densities similar to that of acrylic was used for measuring the effect of X-ray scatter on image contrast. Contrast ratios of the inserts and acrylic in cone-beam setup degraded 36.9% in average compared with fan-beam setup. A tumor-bearing mouse was scanned by the micro-CT system. The tumor-to-background contrast ratios were measured to be 0.331 and 0.249, respectively, with fan-beam and cone-beam setups.

  7. Reduction of variable-truncation artifacts from beam occlusion during in situ x-ray tomography

    Science.gov (United States)

    Borg, Leise; Jørgensen, Jakob S.; Frikel, Jürgen; Sporring, Jon

    2017-12-01

    Many in situ x-ray tomography studies require experimental rigs which may partially occlude the beam and cause parts of the projection data to be missing. In a study of fluid flow in porous chalk using a percolation cell with four metal bars drastic streak artifacts arise in the filtered backprojection (FBP) reconstruction at certain orientations. Projections with non-trivial variable truncation caused by the metal bars are the source of these variable-truncation artifacts. To understand the artifacts a mathematical model of variable-truncation data as a function of metal bar radius and distance to sample is derived and verified numerically and with experimental data. The model accurately describes the arising variable-truncation artifacts across simulated variations of the experimental setup. Three variable-truncation artifact-reduction methods are proposed, all aimed at addressing sinogram discontinuities that are shown to be the source of the streaks. The ‘reduction to limited angle’ (RLA) method simply keeps only non-truncated projections; the ‘detector-directed smoothing’ (DDS) method smooths the discontinuities; while the ‘reflexive boundary condition’ (RBC) method enforces a zero derivative at the discontinuities. Experimental results using both simulated and real data show that the proposed methods effectively reduce variable-truncation artifacts. The RBC method is found to provide the best artifact reduction and preservation of image features using both visual and quantitative assessment. The analysis and artifact-reduction methods are designed in context of FBP reconstruction motivated by computational efficiency practical for large, real synchrotron data. While a specific variable-truncation case is considered, the proposed methods can be applied to general data cut-offs arising in different in situ x-ray tomography experiments.

  8. Grazing Incidence angle X-ray Diffraction of implanted stainless steel: comparison between simulated data and experimental data

    International Nuclear Information System (INIS)

    Dudognon, J.; Vayer, M.; Pineau, A.; Erre, R.

    2006-01-01

    Austenitic stainless steel was implanted with specific elements using specific conditions. The goal of this studies was to compare the predicted structural modifications within the implanted layer with the experimental ones observed by Grazing Incidence angle X-ray Diffraction (GIXD).During ion implantation implanted austenite steel layer undergoes modifications such as austenite lattice expansion, ferrite apparition and structure destruction. The X-ray diffraction austenite peak shape was predicted using the concentration depth profile of implanted element, the information depth profile of diffracted intensity and a linear relationship between implanted element concentration and lattice parameter. Experimental and predicted austenite X-ray diffraction peaks are in good accordance as long as the implanted layer contents mainly austenite. Whatever the nature of implanted element, ferrite appears above a given threshold of incoming energy amount. Moreover, the structure of the implanted layer is destroyed above a given amount of incoming energy

  9. Detector, collimator and real-time reconstructor for a new scanning-beam digital x-ray (SBDX) prototype.

    Science.gov (United States)

    Speidel, Michael A; Tomkowiak, Michael T; Raval, Amish N; Dunkerley, David A P; Slagowski, Jordan M; Kahn, Paul; Ku, Jamie; Funk, Tobias

    Scanning-beam digital x-ray (SBDX) is an inverse geometry fluoroscopy system for low dose cardiac imaging. The use of a narrow scanned x-ray beam in SBDX reduces detected x-ray scatter and improves dose efficiency, however the tight beam collimation also limits the maximum achievable x-ray fluence. To increase the fluence available for imaging, we have constructed a new SBDX prototype with a wider x-ray beam, larger-area detector, and new real-time image reconstructor. Imaging is performed with a scanning source that generates 40,328 narrow overlapping projections from 71 × 71 focal spot positions for every 1/15 s scan period. A high speed 2-mm thick CdTe photon counting detector was constructed with 320×160 elements and 10.6 cm × 5.3 cm area (full readout every 1.28 μs), providing an 86% increase in area over the previous SBDX prototype. A matching multihole collimator was fabricated from layers of tungsten, brass, and lead, and a multi-GPU reconstructor was assembled to reconstruct the stream of captured detector images into full field-of-view images in real time. Thirty-two tomosynthetic planes spaced by 5 mm plus a multiplane composite image are produced for each scan frame. Noise equivalent quanta on the new SBDX prototype measured 63%-71% higher than the previous prototype. X-ray scatter fraction was 3.9-7.8% when imaging 23.3-32.6 cm acrylic phantoms, versus 2.3-4.2% with the previous prototype. Coronary angiographic imaging at 15 frame/s was successfully performed on the new SBDX prototype, with live display of either a multiplane composite or single plane image.

  10. X-ray tubes

    International Nuclear Information System (INIS)

    Young, R.W.

    1979-01-01

    A form of x-ray tube is described which provides satisfactory focussing of the electron beam when the beam extends for several feet from gun to target. Such a tube can be used for computerised tomographic scanning. (UK)

  11. Performance test for implantation of a primary standard of low energy X-ray beams

    International Nuclear Information System (INIS)

    Cardoso, Ricardo de Souza; Bossio, Francisco; Peixoto, Jose Guilherme P.

    2005-01-01

    The implementation of a standard laboratory of calibration chambers that will serve to radiotherapy activities, radiodiagnosis and radioprotection, depends on the knowledge of physical and dosimetric parameters that characterize the quality of the radiation beam. With the aim of verifying the reliability of the ionizing free-air chamber with variable volume manufactured by Victoreen Instruments, model 481, as a primary standard, a study of the performance of the chamber to x-rays qualities of low energy was developed in this work. These qualities are the ones recommended by 'Bureau International des Poids et Mesures' - BIPM, for daily routine of the calibration service performed by the 'Laboratorio Nacional de Metrologia das Radiacoes Ionizantes - LNMRI/IRD, for calibration of this secondary standard chambers that serve to the control in hospitals, clinics and industries. The results obtained at the present work show that the Victoreen chamber model 481 behaves as a primary standard, being easy to handle and having simple mechanical construction, and showing an expanded uncertainty equal to 0,26%, regarding the quality of the radiation beam of 30 kV. However, some of the equipment used at the present study need to be submitted to a strict routine calibration, in order for the laboratory to be in accordance with the recommendations of the standard ABNT -NBR ISO/IEC 17025 (2003). (author)

  12. Carbon-ion beam irradiation kills X-ray-resistant p53-null cancer cells by inducing mitotic catastrophe.

    Directory of Open Access Journals (Sweden)

    Napapat Amornwichet

    Full Text Available BACKGROUND AND PURPOSE: To understand the mechanisms involved in the strong killing effect of carbon-ion beam irradiation on cancer cells with TP53 tumor suppressor gene deficiencies. MATERIALS AND METHODS: DNA damage responses after carbon-ion beam or X-ray irradiation in isogenic HCT116 colorectal cancer cell lines with and without TP53 (p53+/+ and p53-/-, respectively were analyzed as follows: cell survival by clonogenic assay, cell death modes by morphologic observation of DAPI-stained nuclei, DNA double-strand breaks (DSBs by immunostaining of phosphorylated H2AX (γH2AX, and cell cycle by flow cytometry and immunostaining of Ser10-phosphorylated histone H3. RESULTS: The p53-/- cells were more resistant than the p53+/+ cells to X-ray irradiation, while the sensitivities of the p53+/+ and p53-/- cells to carbon-ion beam irradiation were comparable. X-ray and carbon-ion beam irradiations predominantly induced apoptosis of the p53+/+ cells but not the p53-/- cells. In the p53-/- cells, carbon-ion beam irradiation, but not X-ray irradiation, markedly induced mitotic catastrophe that was associated with premature mitotic entry with harboring long-retained DSBs at 24 h post-irradiation. CONCLUSIONS: Efficient induction of mitotic catastrophe in apoptosis-resistant p53-deficient cells implies a strong cancer cell-killing effect of carbon-ion beam irradiation that is independent of the p53 status, suggesting its biological advantage over X-ray treatment.

  13. Interlaced X-ray Microplanar Beams: A Radiosurgery Approach with Clinical Potential

    Energy Technology Data Exchange (ETDEWEB)

    Dilimanian,F.; Zhong, Z.; Bacarian, T.; Benveniste, H.; Romanelli, P.; Wang, R.; Welwart, J.; Yuasa, T.; Rosen, E.; Anschel, D.

    2006-01-01

    Studies have shown that x-rays delivered as arrays of parallel microplanar beams (microbeams), 25- to 90-{micro}m thick and spaced 100-300 {micro}m on-center, respectively, spare normal tissues including the central nervous system (CNS) and preferentially damage tumors. However, such thin microbeams can only be produced by synchrotron sources and have other practical limitations to clinical implementation. To approach this problem, we first studied CNS tolerance to much thicker beams. Three of four rats whose spinal cords were exposed transaxially to four 400-Gy, 0.68-mm microbeams, spaced 4 mm, and all four rats irradiated to their brains with large, 170-Gy arrays of such beams spaced 1.36 mm, all observed for 7 months, showed no paralysis or behavioral changes. We then used an interlacing geometry in which two such arrays at a 90 deg angle produced the equivalent of a contiguous beam in the target volume only. By using this approach, we produced 90-, 120-, and 150-Gy 3.4 x 3.4 x 3.4 mm3 exposures in the rat brain. MRIs performed 6 months later revealed focal damage within the target volume at the 120- and 150-Gy doses but no apparent damage elsewhere at 120 Gy. Monte Carlo calculations indicated a 30-{micro}{micro}m dose falloff (80-20%) at the edge of the target, which is much less than the 2- to 5-mm value for conventional radiotherapy and radiosurgery. These findings strongly suggest potential application of interlaced microbeams to treat tumors or to ablate nontumorous abnormalities with minimal damage to surrounding normal tissue.

  14. Interlaced X-ray Microplanar Beams: A Radiosurgery Approach with Clinical Potential

    International Nuclear Information System (INIS)

    Dilimanian, F.; Zhong, Z.; Bacarian, T.; Benveniste, H.; Romanelli, P.; Wang, R.; Welwart, J.; Yuasa, T.; Rosen, E.; Anschel, D.

    2006-01-01

    Studies have shown that x-rays delivered as arrays of parallel microplanar beams (microbeams), 25- to 90-(micro)m thick and spaced 100-300 (micro)m on-center, respectively, spare normal tissues including the central nervous system (CNS) and preferentially damage tumors. However, such thin microbeams can only be produced by synchrotron sources and have other practical limitations to clinical implementation. To approach this problem, we first studied CNS tolerance to much thicker beams. Three of four rats whose spinal cords were exposed transaxially to four 400-Gy, 0.68-mm microbeams, spaced 4 mm, and all four rats irradiated to their brains with large, 170-Gy arrays of such beams spaced 1.36 mm, all observed for 7 months, showed no paralysis or behavioral changes. We then used an interlacing geometry in which two such arrays at a 90 deg angle produced the equivalent of a contiguous beam in the target volume only. By using this approach, we produced 90-, 120-, and 150-Gy 3.4 x 3.4 x 3.4 mm3 exposures in the rat brain. MRIs performed 6 months later revealed focal damage within the target volume at the 120- and 150-Gy doses but no apparent damage elsewhere at 120 Gy. Monte Carlo calculations indicated a 30-(micro)(micro)m dose falloff (80-20%) at the edge of the target, which is much less than the 2- to 5-mm value for conventional radiotherapy and radiosurgery. These findings strongly suggest potential application of interlaced microbeams to treat tumors or to ablate nontumorous abnormalities with minimal damage to surrounding normal tissue

  15. First observation of meridional focusing of an x-ray beam using diffraction by a crystal with a transverse groove

    Czech Academy of Sciences Publication Activity Database

    Hrdý, Jaromír; Franc, František; Artemiev, Nikolai; Hrdá, Jaromíra; Ziegler, E.; Bigault, Th.; Freud, A. K.

    2001-01-01

    Roč. 8, - (2001), s. 1203-1206 ISSN 0909-0495 R&D Projects: GA AV ČR IAA1010104; GA MPO PZ-CH/22 Institutional research plan: CEZ:AV0Z1010914 Keywords : x-ray beam Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.519, year: 2001

  16. Dosimetry and monitoring of X-rays narrow beams produced by linear particle accelerator, for using in radiosurgery

    International Nuclear Information System (INIS)

    Campos, J.C.F.; Vizeu, D.M.

    1987-01-01

    The main characteristics of X-rays narrow beams dosimetry and monitoring are examined, aiming the introduction of this system in brain radiosurgery. The non-protocolize detectors are used, once that the detectors used in therapy by megavoltage were projected for dosimetry with an irradiation field above 40 mm diameter. (C.G.C.) [pt

  17. A Comparison of Different Types of Coherent Radiation of a Relativistic Electron-Beam in the X-Ray Range

    NARCIS (Netherlands)

    Tulupov, A. V.

    1993-01-01

    A comparison of the spectral-angular intensity of radiation of a relativistic electron beam is carried oui in the X-ray range for different radiation types: transition radiation: parametric Cherenkov radiation; undulattor radiation: and radiation in the electromagnetic wave field. Simple analytical

  18. Micronuclei in human peripheral blood lymphocytes exposed to mixed beams of X-rays and alpha particles

    Czech Academy of Sciences Publication Activity Database

    Staaf, E.; Brehwens, K.; Haghdoost, S.; Nievaart, S.; Pachnerová Brabcová, Kateřina; Czub, J.; Braziewicz, J.; Wojcik, A.

    2012-01-01

    Roč. 51, č. 3 (2012), s. 283-293 ISSN 0301-634X Institutional research plan: CEZ:AV0Z10480505 Keywords : Micronuclei * LET * Combined exposure * Mixed beams * Alpha particles * X-rays Subject RIV: BO - Biophysics Impact factor: 1.754, year: 2012

  19. Development of a Reference System for the determination of the personal dose equivalent and the constancy of X- Ray beams

    International Nuclear Information System (INIS)

    Vivolo, Vitor

    2006-01-01

    A reference system for the determination of the personal dose equivalent, Hp (10), and a quality control program of X-ray equipment used In radioprotection require the periodic verification of the X-ray beams constancy. In this work, two parallel-plate ionization chambers were developed with inner electrodes of different materials, and inserted into PMMA slab phantoms. One ionization chamber was developed with inner carbon electrodes and the other with inner aluminium electrodes. The two ionization chambers can be used as a Tandem system. The different energy response of the two ionization chambers allowed the development of the Tandem system that is very useful for the checking of the constancy of beam qualities. Standard intermediary energy X-ray beams (from 48 keV to 118 keV), radioprotection level, were established through the development of a dosimetric methodology and the analysis of their physical parameters. The ionization chambers were studied in relation to their operational characteristics, and they were calibrated in X-ray beams (radioprotection, diagnostic radiology, mammography and radiotherapy levels) in accordance to international recommendations. They presented good performance. The determination procedure of personal dose equivalent, Hp (10), was established. (author)

  20. NaI(Tl) scintillator detectors stripping procedure for air kerma measurements of diagnostic X-ray beams

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, L.S.R. [Centro Tecnológico do Exército, CTEx (Brazilian Army Technological Center), Av. das Américas n° 28705, 23085-470 Rio de Janeiro (Brazil); Instituto de Radioprotecão e Dosimetria, CNEN/IRD (Institute for Radioprotection and Dosimetry, CNEN/IRD), Av. Salvador Allende s/no, P.O. Box 37750, 22783-127 Barra da Tijuca, Rio de Janeiro (Brazil); Conti, C.C., E-mail: ccconti@ird.gov.br [Instituto de Radioprotecão e Dosimetria, CNEN/IRD (Institute for Radioprotection and Dosimetry, CNEN/IRD), Av. Salvador Allende s/no, P.O. Box 37750, 22783-127 Barra da Tijuca, Rio de Janeiro (Brazil); Amorim, A.S.; Balthar, M.C.V. [Centro Tecnológico do Exército, CTEx (Brazilian Army Technological Center), Av. das Américas n° 28705, 23085-470 Rio de Janeiro (Brazil)

    2013-03-21

    Air kerma is an essential quantity for the calibration of national standards used in diagnostic radiology and the measurement of operating parameters used in radiation protection. Its measurement within the appropriate limits of accuracy, uncertainty and reproducibility is important for the characterization and control of the radiation field for the dosimetry of the patients submitted to diagnostic radiology and, also, for the assessment of the system which produces radiological images. Only the incident beam must be considered for the calculation of the air kerma. Therefore, for energy spectrum, counts apart the total energy deposition in the detector must be subtracted. It is necessary to establish a procedure to sort out the different contributions to the original spectrum and remove the counts representing scattered photons in the detector’s materials, partial energy deposition due to the interactions in the detector active volume and, also, the escape peaks contributions. The main goal of this work is to present spectrum stripping procedure, using the MCNP Monte Carlo computer code, for NaI(Tl) scintillation detectors to calculate the air kerma due to an X-ray beam usually used in medical radiology. The comparison between the spectrum before stripping procedure against the reference value showed a discrepancy of more than 63%, while the comparison with the same spectrum after the stripping procedure showed a discrepancy of less than 0.2%.

  1. Molecular beam epitaxy of GeTe-Sb2Te3 phase change materials studied by X-ray diffraction

    International Nuclear Information System (INIS)

    Shayduk, Roman

    2010-01-01

    The integration of phase change materials into semiconductor heterostructures may lead to the development of a new generation of high density non-volatile phase change memories. Epitaxial phase change materials allow to study the detailed structural changes during the phase transition and to determine the scaling limits of the memory. This work is dedicated to the epitaxial growth of Ge-Sb-Te phase change alloys on GaSb(001). We deposit Ge-Sb-Te (GST) films on GaSb(001) substrates by means of molecular beam epitaxy (MBE). The film orientation and lattice constant evolution is determined in real time during growth using grazing incidence X-ray diffraction (GID). The nucleation stage of the growth is studied in situ using reflection high energy electron diffraction (RHEED). Four growth regimes of GST on GaSb(001) were observed: amorphous, polycrystalline, incubated epitaxial and direct epitaxial. Amorphous film grows for substrate temperatures below 100 C. For substrate temperatures in the range 100-160 C, the film grows in polycrystalline form. Incubated epitaxial growth is observed at temperatures from 180 to 210 C. This growth regime is characterized by an initial 0.6nm thick amorphous layer formation, which crystallizes epitaxially as the film thickness increases. The determined lattice constant of the films is 6.01 A, very close to that of the metastable GST phase. The films predominantly possess an epitaxial cube-on-cube relationship. At higher temperatures the films grow epitaxially, however the growth rate is rapidly decreasing with temperature. At temperatures above 270 C the growth rate is zero. The composition of the grown films is close to 2:2:5 for Ge, Sb and Te, respectively. The determined crystal structure of the films is face centered cubic (FCC) with a rhombohedral distortion. The analysis of X-ray peak widths gives a value for the rhombohedral angle of 89.56 . We observe two types of reflections in reciprocal space indicating two FCC sublattices in

  2. Performance Test of the Next Generation X-Ray Beam Position Monitor System for The APS Upgrade

    Energy Technology Data Exchange (ETDEWEB)

    Yang, B.; Lee, S.; Westferro, F.; Jaski, Y.; Lenkszus, F.; Sereno, N.; Ramanathan, M.

    2017-03-25

    The Advanced Photon Source is developing its next major upgrade (APS-U) based on the multi-bend achromat lattice. Improved beam stability is critical for the upgrade and will require keeping short-time beam angle change below 0.25 µrad and long-term angle drift below 0.6 µrad. A reliable white x-ray beam diagnostic system in the front end will be a key part of the planned beam stabilization system. This system includes an x-ray beam position monitor (XBPM) based on x-ray fluorescence (XRF) from two specially designed GlidCop A-15 absorbers, a second XBPM using XRF photons from the Exit Mask, and two white beam intensity monitors using XRF from the photon shutter and Compton-scattered photons from the front end beryllium window or a retractable diamond film in windowless front ends. We present orbit stability data for the first XBPM used in the feedback control during user operations, as well as test data from the second XBPM and the intensity monitors. They demonstrate that the XBPM system meets APS-U beam stability requirements.

  3. Development of a hybrid molecular beam epitaxy deposition system for in situ surface x-ray studies

    Science.gov (United States)

    Andersen, Tassie K.; Cook, Seyoung; Benda, Erika; Hong, Hawoong; Marks, Laurence D.; Fong, Dillon D.

    2018-03-01

    A portable metalorganic gas delivery system designed and constructed to interface with an existing molecular beam epitaxy chamber at beamline 33-ID-E of the Advanced Photon Source is described. This system offers the ability to perform in situ X-ray measurements of complex oxide growth via hybrid molecular beam epitaxy. The performance of the hybrid molecular beam epitaxy system while delivering metalorganic source materials is described. The high-energy X-ray scattering capabilities of the hybrid molecular beam epitaxy system are demonstrated both on oxide films grown solely from the metalorganic source and ABO3 oxide perovskites containing elements from both the metalorganic source and a traditional effusion cell.

  4. Constraints on photon pulse duration from longitudinal electron beam diagnostics at a soft x-ray free-electron laser

    Directory of Open Access Journals (Sweden)

    C. Behrens

    2012-03-01

    Full Text Available The successful operation of x-ray free-electron lasers (FELs, like the Linac Coherent Light Source or the Free-Electron Laser in Hamburg (FLASH, makes unprecedented research on matter at atomic length and ultrafast time scales possible. However, in order to take advantage of these unique light sources and to meet the strict requirements of many experiments in photon science, FEL photon pulse durations need to be known and tunable. This can be achieved by controlling the FEL driving electron beams, and high-resolution longitudinal electron beam diagnostics can be utilized to provide constraints on the expected FEL photon pulse durations. In this paper, we present comparative measurements of soft x-ray pulse durations and electron bunch lengths at FLASH. The soft x-ray pulse durations were measured by FEL radiation pulse energy statistics and compared to electron bunch lengths determined by frequency-domain spectroscopy of coherent transition radiation in the terahertz range and time-domain longitudinal phase space measurements. The experimental results, theoretical considerations, and simulations show that high-resolution longitudinal electron beam diagnostics provide reasonable constraints on the expected FEL photon pulse durations. In addition, we demonstrated the generation of soft x-ray pulses with durations below 50 fs (FWHM after the implementation of the new uniform electron bunch compression scheme used at FLASH.

  5. Degradation of poly(methylmethacrylate) by deep ultraviolet, x-ray, electron beam, and proton beam irradiations

    International Nuclear Information System (INIS)

    Choi, J.O.; Moore, J.A.; Corelli, J.C.; Silverman, J.P.; Bakhru, H.

    1988-01-01

    The chemical changes in poly(methylmethacrylate) (PMMA) caused by irradiation with deep ultraviolet (UV), x-ray, electron, and proton beams were studied by gel permeation chromatography, Fourier-transform infrared, and UV spectroscopy. The quantitative analysis of spectroscopic changes (Beer's law) demonstrated a 1:1 correspondence between the disappearance of ester groups and the generation of double bonds in the polymer chain by all types of radiation. The ratio of main chain scission to changes in the number of ester groups and unsaturated bonds was compared to determine the characteristics of degradation of PMMA by the different types of radiation. This ratio for deep UV data was very close to the quantum yield of main chain scission of PMMA as reported in the literature. High-energy radiation was /similar to/0 x more efficient than deep UV in causing main chain scission with removal of fewer ester groups. Protons induced more main chain scission than electrons. X-ray irradiation was the most efficient at causing main chain scission of the four different types of radiation

  6. A tetrahedron beam computed tomography benchtop system with a multiple pixel field emission x-ray tube.

    Science.gov (United States)

    Xu, Xiaochao; Kim, Joshua; Laganis, Philip; Schulze, Derek; Liang, Yongguang; Zhang, Tiezhi

    2011-10-01

    To demonstrate the feasibility of Tetrahedron Beam Computed Tomography (TBCT) using a carbon nanotube (CNT) multiple pixel field emission x-ray (MPFEX) tube. A multiple pixel x-ray source facilitates the creation of novel x-ray imaging modalities. In a previous publication, the authors proposed a Tetrahedron Beam Computed Tomography (TBCT) imaging system which comprises a linear source array and a linear detector array that are orthogonal to each other. TBCT is expected to reduce scatter compared with Cone Beam Computed Tomography (CBCT) and to have better detector performance. Therefore, it may produce improved image quality for image guided radiotherapy. In this study, a TBCT benchtop system has been developed with an MPFEX tube. The tube has 75 CNT cold cathodes, which generate 75 x-ray focal spots on an elongated anode, and has 4 mm pixel spacing. An in-house-developed, 5-row CT detector array using silicon photodiodes and CdWO(4) scintillators was employed in the system. Hardware and software were developed for tube control and detector data acquisition. The raw data were preprocessed for beam hardening and detector response linearity and were reconstructed with an FDK-based image reconstruction algorithm. The focal spots were measured at about 1 × 2 mm(2) using a star phantom. Each cathode generates around 3 mA cathode current with 2190 V gate voltage. The benchtop system is able to perform TBCT scans with a prolonged scanning time. Images of a commercial CT phantom were successfully acquired. A prototype system was developed, and preliminary phantom images were successfully acquired. MPFEX is a promising x-ray source for TBCT. Further improvement of tube output is needed in order for it to be used in clinical TBCT systems.

  7. Study of salinity in aqueous medium using X-Ray beam with MCNP-X code

    International Nuclear Information System (INIS)

    Barbosa, Caroline M.; Braz, Delson

    2017-01-01

    In offshore production, it is possible that the produced water presents geochemical characteristics that correspond to the mixture of formation water (connate water) and the sea water (injection water), and the physical-chemical behavior of the injected water allows a considerable variation in the index of salinity altering the water/oil ratio during transportation and/or extraction. Injection water is generally used to raise the reservoir pressure, increasing the percentage of extracted oil. This water has a significant amount of salts that generate some difficulties, such as measuring fractions of volume in multiphase systems. One way to check the effects of salinity would be to regularly measure the amount of salt present in the water. In this way, this work presents a methodology to measure the concentration and the types of salts using nuclear techniques through the MCNP-X computational code. The measurement geometry uses an X-ray beam (40-100 keV) and NaI(Tl) scintillation detector positioned diametrically opposed to the source. The studied samples were the NaCl, KCl and MgCl 2 salts in aqueous solution. The results present the possibility of differentiating the formation and injection waters due to differences in the salt concentrations. (author)

  8. Study of salinity in aqueous medium using X-Ray beam with MCNP-X code

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, Caroline M.; Braz, Delson [Coordenacao de Pos-Graduacao e Pesquisa de Engenharia (PEN/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear; Salgado, César M., E-mail: cbarbosa@nuclear.ufrj.br, E-mail: delson@nuclear.ufrj.br, E-mail: otero@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2017-07-01

    In offshore production, it is possible that the produced water presents geochemical characteristics that correspond to the mixture of formation water (connate water) and the sea water (injection water), and the physical-chemical behavior of the injected water allows a considerable variation in the index of salinity altering the water/oil ratio during transportation and/or extraction. Injection water is generally used to raise the reservoir pressure, increasing the percentage of extracted oil. This water has a significant amount of salts that generate some difficulties, such as measuring fractions of volume in multiphase systems. One way to check the effects of salinity would be to regularly measure the amount of salt present in the water. In this way, this work presents a methodology to measure the concentration and the types of salts using nuclear techniques through the MCNP-X computational code. The measurement geometry uses an X-ray beam (40-100 keV) and NaI(Tl) scintillation detector positioned diametrically opposed to the source. The studied samples were the NaCl, KCl and MgCl{sub 2} salts in aqueous solution. The results present the possibility of differentiating the formation and injection waters due to differences in the salt concentrations. (author)

  9. Replaceable Be and Al windows for x-ray beam lines

    International Nuclear Information System (INIS)

    Oversluizen, T.; Stefan, P.M.

    1987-01-01

    Construction details and results of on-going performance tests are presented for two ultra-high vacuum compatible, free-convection cooled window assemblies in which the window disk is easily replaceable. In the Be window assembly, an 0.25 mm thick Be disk, 38 mm in diameter is sealed into a stainless steel adapter flange using 0.5 mm diameter pure Al wire. The assembly is leak tight to better than 1 x 10 -10 atm cm 3 /sec before and after multiple bakeouts to 250 0 C. However, an unexplained temperature-dependent He leak, with a maximum magnitude in the low 10 -10 atm cm 3 /sec range at 250 0 C, appears during bakeout. Possible causes for this leak are discussed. In the Al window assembly, a 25 μm thick Al disc, 60 mm in diameter acts as the sealing medium as well as the window material over a 10 mm by 50 mm opening. This assembly remains leak tight to better than 1 x 10 -10 atm cm 3 /sec throughout multiple bakeouts to 150 0 C and has been successfully tested in white and monochromatic beam lines at the NSLS x-ray ring. 25 refs

  10. Replaceable Be and Al windows for X-ray beam lines

    International Nuclear Information System (INIS)

    Oversluizen, T.; Stefan, P.M.

    1988-01-01

    Construction details and results of on-going performance tests are presented for two ultrahigh vacuum compatible, free-convection cooled window assemblies in which the window disk is easily replaceable. In the Be window assembly, an 0.25 mm thick Be disk, 38 mm in diameter, is sealed into a stainless steel adapter flange using 0.5 mm diameter pure Al wire. The assembly is leak tight to better than 1x10 -10 atm cm 3 /s before and after multiple bakeouts to 250 0 C. However, an unexplained temperature-dependent He leak, with a maximum magnitude in the low 10 -10 atm cm 3 /s range at 250 0 C, appears during bakeout. Possible causes for this leak are discussed. In the Al window assembly, a 25 μm thick Al disc, 60 mm in diameter, acts as the sealing medium as well as the window material over a 10 mm x 50 mm opening. This assembly remains leak tight to better than 1x10 -10 atm cm 3 /s throughout multiple bakeouts to 150 0 C and has been successfully rested in white and monochromatic beam lines at the NSLS X-ray ring. (orig.)

  11. Specific features of two diffraction schemes for a widely divergent X-ray beam

    Energy Technology Data Exchange (ETDEWEB)

    Avetyan, K. T.; Levonyan, L. V.; Semerjian, H. S.; Arakelyan, M. M., E-mail: marakelyan@ysu.am; Badalyan, O. M. [Yerevan State University (Armenia)

    2015-03-15

    We investigated the specific features of two diffraction schemes for a widely divergent X-ray beam that use a circular diaphragm 30–50 μm in diameter as a point source of characteristic radiation. In one of the schemes, the diaphragm was set in front of the crystal (the diaphragm-crystal (d-c) scheme); in the other, it was installed behind the crystal (the crystal-diaphragm (c-d) scheme). It was established that the diffraction image in the c-d scheme is a topographic map of the investigated crystal area. In the d-c scheme at L = 2l (l and L are the distances between the crystal and the diaphragm and between the photographic plate and the diaphragm, respectively), the branches of hyperbolas formed in this family of planes (hkl) by the characteristic K{sub α} and K{sub β} radiations, including higher order reflections, converge into one straight line. It is experimentally demonstrated that this convergence is very sensitive to structural inhomogeneities in the crystal under study.

  12. Application of a model based on a pair of Laplace transforms for standard low-energy X-ray beams spectral reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Alessandro M., E-mail: amcosta@usp.b [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Filosofia, Ciencias e Letras. Dept. de Fisica e Matematica; Potiens, Maria da Penha A., E-mail: mppalbu@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP) Sao Paulo, SP (Brazil)

    2009-07-01

    The direct measurement of the spectrum of an X-ray beam by some spectroscopic method is relatively difficult and expensive. Spectra can be alternatively derived by an indirect method from measurements of transmission curve of the X-ray beam and the use of Laplace transforms. The objective of this work was the application of an indirect method that use a spectral model based on a pair of Laplace transforms to reconstruct experimental published spectra of standard low energy X-ray beams at radiation protection level and determine the mean photon energy from the reconstructed spectra for radiation quality specification. The spectral model was applied using calculated transmission curves and the reconstructed spectra provided a coarse approximation to experimental data. Even though, the mean photon energy of the X-ray beams determined from these reconstructed spectra present a satisfactory result showing the value of the analysis of transmission curves for the X-ray beam quality specification. (author)

  13. CRL X-ray tube

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  14. CRL X-RAY TUBE

    OpenAIRE

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

    2015-01-01

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

  15. Element sensitive reconstruction of nanostructured surfaces with finite elements and grazing incidence soft X-ray fluorescence.

    Science.gov (United States)

    Soltwisch, Victor; Hönicke, Philipp; Kayser, Yves; Eilbracht, Janis; Probst, Jürgen; Scholze, Frank; Beckhoff, Burkhard

    2018-03-29

    The geometry of a Si3N4 lamellar grating was investigated experimentally with reference-free grazing-incidence X-ray fluorescence analysis. While simple layered systems are usually treated with the matrix formalism to determine the X-ray standing-wave field, this approach fails for laterally structured surfaces. Maxwell solvers based on finite elements are often used to model electrical field strengths for any 2D or 3D structures in the optical spectral range. We show that this approach can also be applied in the field of X-rays. The electrical field distribution obtained with the Maxwell solver can subsequently be used to calculate the fluorescence intensities in full analogy to the X-ray standing-wave field obtained by the matrix formalism. Only the effective 1D integration for the layer system has to be replaced by a 2D integration of the finite elements, taking into account the local excitation conditions. We will show that this approach is capable of reconstructing the geometric line shape of a structured surface with high elemental sensitivity. This combination of GIXRF and finite-element simulations paves the way for a versatile characterization of nanoscale-structured surfaces.

  16. X-Ray Beam Studies of Charge Sharing in Small Pixel, Spectroscopic, CdZnTe Detectors

    Science.gov (United States)

    Allwork, Christopher; Kitou, Dimitris; Chaudhuri, Sandeep; Sellin, Paul J.; Seller, Paul; Veale, Matthew C.; Tartoni, Nicola; Veeramani, Perumal

    2012-08-01

    Recent advances in the growth of CdZnTe material have allowed the development of small pixel, spectroscopic, X-ray imaging detectors. These detectors have applications in a diverse range of fields such as medical, security and industrial sectors. As the size of the pixels decreases relative to the detector thickness, the probability that charge is shared between multiple pixels increases due to the non zero width of the charge clouds drifting through the detector. These charge sharing events will result in a degradation of the spectroscopic performance of detectors and must be considered when analyzing the detector response. In this paper charge sharing and charge loss in a 250 μm pitch CdZnTe pixel detector has been investigated using a mono-chromatic X-ray beam at the Diamond Light Source, U.K. Using a 20 μm beam diameter the detector response has been mapped for X-ray energies both above (40 keV) and below (26 keV) the material K-shell absorption energies to study charge sharing and the role of fluorescence X-rays in these events.

  17. Measure of the attenuation curve of a beam of X-rays with TLD-100 dosimeters of LiF

    International Nuclear Information System (INIS)

    Bonzi, E. V.; Mainardi, R. T.; Germanier, A.; Delgado, V.

    2011-10-01

    The attenuation curve of a beam of X-rays represents the beam intensity in function of the attenuator thickness interposed between the source and the detector. To know with the major possible precision the attenuation curve is indispensable in procedures of spectral reconstruction. Their periodic measuring also offers valuable information on the correct operation of a tube of X-rays, diagnostic or therapy, when not have a specific detector for that activity. In this work was measured the attenuation curve of a tube of X-rays operated to 50 kV and 0.5 ma, using existent elements in any diagnostic or therapy laboratory with radiations. In the measures commercial aluminum foil was used, bent until 24 times and thermoluminescent dosimeters TLD 100 - LiF. Also, for comparison, was measured this attenuation curve with an ionization chamber brand Capintec model 192. Was determined by X-rays fluorescence the composition of the aluminium foil, since the present elements in the alloy can to affect the form of the attenuation curve. It is interesting to observe that these elements are in very low proportion (ppm) that they do not alter the attenuation capacity of the pure aluminium. Finally in a precision balance we weigh a big piece (30 cm x 100 cm) of aluminium foil and we obtained the thickness in g/c m2. It is possible to obtain attenuation curves of a beam of X-rays, with a high precision procedure and reproducibility. The use of TLD-100 dosimeters of LiF or similar makes that this activity was also quick and simple. (Author)

  18. Characterisation of corrosion deposits induced by carbon dioxide on mild steel using grazing incidence x-ray and synchrotron radiation diffraction

    International Nuclear Information System (INIS)

    Sembiring, S.; O'Connor, B; Li, D.; Buckley, C.; Van Riessen, A.; De Marco, R.

    1999-01-01

    Full text: Grazing incidence diffraction, using x-rays (GIXRD) and synchrotron radiation (GISRD), is being applied for near-surface characterisation of corrosion deposits formed on the internal surfaces of mild steel pipelines which are used to deliver natural gas from offshore deposits in Western Australia. These techniques are being employed to construct phase composition depth-profiles of corrosion product phases. The GIXRD data are being measured with CuKα radiation using a Siemens D5000 x-ray diffractometer, fitted with a primary beam slit system for incidence angle control and also with a diffracted beam monochromator; and the GISRD data have been acquired with the BIGDIFF instrument on the ANBF beamline in Tsukuba, Japan. The mild steel test samples are prepared with a laboratory reactor in which the corrosion conditions are simulated in a controlled manner. Results obtained to date have shown that two phases are readily observed in addition to the a-Fe phase from the mild steel substrate: (1) FeCO 3 (siderite) induced by CO 2 dissolved in the water flowing through the pipeline, and (2) CaCO 3 (calcite) deposited on the mild steel surface by reaction between the CO 2 and calcium ions which are also present in the water flowing through the pipeline. Supporting measurements from SEM imaging and associated EDS analysis will also be presented

  19. Development of grazing incidence multilayer mirrors for hard X-ray focusing telescopes

    DEFF Research Database (Denmark)

    Mao, Peter H.; Harrison, Fiona A.; Platonov, Yuriy Y.

    1997-01-01

    We are developing depth-graded, multilayer-coated mirrors for astrophysical hard X-ray focusing telescopes. In this paper, we discuss the primary technical challenges associated with the multilayer coatings, and report on progress to date. We have sputtered constant d-spacing and depth-graded W/S...

  20. Medium-sized grazing incidence high-energy X-ray telescopes employing continuously graded multilayers

    DEFF Research Database (Denmark)

    Joensen, K. D.; Christensen, Finn Erland; Schnopper, H. W.

    1993-01-01

    The authors present a concept of continuously graded multilayer structures for medium-sized X-ray telescopes which is based on several material combinations. They show that the theoretical reflectivity characteristics of these structures make them very advantageous when applied to high energy X-r...

  1. Standing-wave effects in grazing-incidence x-ray diffraction from polycrystalline multilayers

    Czech Academy of Sciences Publication Activity Database

    Krčmář, J.; Holý, V.; Horák, L.; Metzger, T. H.; Sobota, Jaroslav

    2008-01-01

    Roč. 103, č. 3 (2008), 033504:1-7 ISSN 0021-8979 Institutional research plan: CEZ:AV0Z20650511 Keywords : acoustic wave interference * carbon * crystallites * interface structure * nickel * optical multilayers * superlattices * X-ray diffraction Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.201, year: 2008

  2. Quantitative determination of the lateral density and intermolecular correlation between proteins anchored on the membrane surfaces using grazing incidence small-angle X-ray scattering and grazing incidence X-ray fluorescence.

    Science.gov (United States)

    Abuillan, Wasim; Vorobiev, Alexei; Hartel, Andreas; Jones, Nicola G; Engstler, Markus; Tanaka, Motomu

    2012-11-28

    As a physical model of the surface of cells coated with densely packed, non-crystalline proteins coupled to lipid anchors, we functionalized the surface of phospholipid membranes by coupling of neutravidin to biotinylated lipid anchors. After the characterization of fine structures perpendicular to the plane of membrane using specular X-ray reflectivity, the same membrane was characterized by grazing incidence small angle X-ray scattering (GISAXS). Within the framework of distorted wave Born approximation and two-dimensional Percus-Yevick function, we can analyze the form and structure factors of the non-crystalline, membrane-anchored proteins for the first time. As a new experimental technique to quantify the surface density of proteins on the membrane surface, we utilized grazing incidence X-ray fluorescence (GIXF). Here, the mean intermolecular distance between proteins from the sulfur peak intensities can be calculated by applying Abelé's matrix formalism. The characteristic correlation distance between non-crystalline neutravidin obtained by the GISAXS analysis agrees well with the intermolecular distance calculated by GIXF, suggesting a large potential of the combination of GISAXS and GIXF in probing the lateral density and correlation of non-crystalline proteins displayed on the membrane surface.

  3. Two-dimensional x-ray magnification based on a monolithic beam conditioner

    Czech Academy of Sciences Publication Activity Database

    Korytár, D.; Mikulík, P.; Ferrari, C.; Hrdý, Jaromír; Baumbach, T.; Freund, A.; Kuběna, A.

    2003-01-01

    Roč. 36, - (2003), s. 1-4 ISSN 0022-3727 R&D Projects: GA AV ČR IAA1010104; GA MŠk OC P7.001 Institutional research plan: CEZ:AV0Z1010914 Keywords : x-ray crystal diffraction * x-ray magnifier Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.265, year: 2003

  4. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... 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 ...

  5. Bone X-Ray (Radiography)

    Medline Plus

    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 ...

  6. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... 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 ...

  7. Quality indexes based on water measurements for low and medium energy x-ray beams: A theoretical study with PENELOPE

    Energy Technology Data Exchange (ETDEWEB)

    Chica, U. [Departamento de Física Atómica, Molecular y Nuclear, Universidad de Granada, E-18071 Granada, Spain and FISRAD S.A.S Carrera 64 a No 22-41, Bogotá D.C. (Colombia); Anguiano, M.; Lallena, A. M., E-mail: lallena@ugr.es [Departamento de Física Atómica, Molecular y Nuclear, Universidad de Granada, E-18071 Granada (Spain); Vilches, M. [Servicio de Radiofísica, Hospital Universitario “San Cecilio”, Avda. Dr. Olóriz, 16, E-18012 Granada (Spain)

    2014-01-15

    Purpose : To study the use of quality indexes based on ratios of absorbed doses in water at two different depths to characterize x-ray beams of low and medium energies. Methods : A total of 55 x-ray beam spectra were generated with the codes XCOMP5R and SPEKCALC and used as input of a series of Monte Carlo simulations performed with PENELOPE, in which the percentage depth doses in water and thek{sub Q,Q{sub 0}} factors, defined in the TRS-398 protocol, were determined for each beam. Some of these calculations were performed by simulating the ionization chamber PTW 30010. Results : The authors found that the relation betweenk{sub Q,Q{sub 0}} and the ratios of absorbed doses at two depths is almost linear. A set of ratios statistically compatible with that showing the best fit has been determined. Conclusions : The results of this study point out which of these ratios of absorbed doses in water could be used to better characterize x-ray beams of low and medium energies.

  8. Dosimetry and monitoring of thin X-ray beam produced by linear particle accelerator, for application in radiography

    International Nuclear Information System (INIS)

    Campos, J.C.F. de.

    1986-01-01

    The dosimetry and monitoring characteristics of thin X-ray beams, and the application of 4MeV linear particle accelerator to radiosurgery are studied. An addition collimation system, consisted of 3 lead collimators, which allows to obtain thin beams of 6,10 and 15 mm of diameter, was fabricated. The stereo taxic system, together with modifications in dispositives, provide the accuracy required in volum-targed location. The dosimetric informations were determined with silicon detector inserted into water simulator. The isodose curves for each beam, and total isodoses simulating the treatment were established using radiographic emulsions in conditions which reproduce real circunstances of pacient irradiation. (M.C.K.) [pt

  9. 3D algebraic iterative reconstruction for cone-beam x-ray differential phase-contrast computed tomography.

    Directory of Open Access Journals (Sweden)

    Jian Fu

    Full Text Available Due to the potential of compact imaging systems with magnified spatial resolution and contrast, cone-beam x-ray differential phase-contrast computed tomography (DPC-CT has attracted significant interest. The current proposed FDK reconstruction algorithm with the Hilbert imaginary filter will induce severe cone-beam artifacts when the cone-beam angle becomes large. In this paper, we propose an algebraic iterative reconstruction (AIR method for cone-beam DPC-CT and report its experiment results. This approach considers the reconstruction process as the optimization of a discrete representation of the object function to satisfy a system of equations that describes the cone-beam DPC-CT imaging modality. Unlike the conventional iterative algorithms for absorption-based CT, it involves the derivative operation to the forward projections of the reconstructed intermediate image to take into account the differential nature of the DPC projections. This method is based on the algebraic reconstruction technique, reconstructs the image ray by ray, and is expected to provide better derivative estimates in iterations. This work comprises a numerical study of the algorithm and its experimental verification using a dataset measured with a three-grating interferometer and a mini-focus x-ray tube source. It is shown that the proposed method can reduce the cone-beam artifacts and performs better than FDK under large cone-beam angles. This algorithm is of interest for future cone-beam DPC-CT applications.

  10. 3D algebraic iterative reconstruction for cone-beam x-ray differential phase-contrast computed tomography.

    Science.gov (United States)

    Fu, Jian; Hu, Xinhua; Velroyen, Astrid; Bech, Martin; Jiang, Ming; Pfeiffer, Franz

    2015-01-01

    Due to the potential of compact imaging systems with magnified spatial resolution and contrast, cone-beam x-ray differential phase-contrast computed tomography (DPC-CT) has attracted significant interest. The current proposed FDK reconstruction algorithm with the Hilbert imaginary filter will induce severe cone-beam artifacts when the cone-beam angle becomes large. In this paper, we propose an algebraic iterative reconstruction (AIR) method for cone-beam DPC-CT and report its experiment results. This approach considers the reconstruction process as the optimization of a discrete representation of the object function to satisfy a system of equations that describes the cone-beam DPC-CT imaging modality. Unlike the conventional iterative algorithms for absorption-based CT, it involves the derivative operation to the forward projections of the reconstructed intermediate image to take into account the differential nature of the DPC projections. This method is based on the algebraic reconstruction technique, reconstructs the image ray by ray, and is expected to provide better derivative estimates in iterations. This work comprises a numerical study of the algorithm and its experimental verification using a dataset measured with a three-grating interferometer and a mini-focus x-ray tube source. It is shown that the proposed method can reduce the cone-beam artifacts and performs better than FDK under large cone-beam angles. This algorithm is of interest for future cone-beam DPC-CT applications.

  11. Scanning x-ray microdiffraction with submicron white beam for strain and orientation mapping in thin films

    Energy Technology Data Exchange (ETDEWEB)

    Tamura, N.; MacDowell, A.A.; Spolenak, R.; Valek, B.C.; Bravman, J.C.; Brown, W.L.; Celestre, R.S.; Padmore, H.A.; Batterman, B.W.; Patel, J.R.

    2003-01-14

    Scanning X-ray Microdiffraction (m-SXRD) combines the use of high brilliance synchrotron sources with the latest achromatic X-ray focusing optics and fast large area 2D-detector technology. Using white beams or a combination of white and monochromatic beams, it allows for orientation and strain/stress mapping of polycrystalline thin films with submicron spatial resolution. The technique is described in detail as applied to the study of thin aluminium and copper blanket films and lines following electromigration testing and/or thermal cycling experiments. It is shown that there are significant orientation and strain/stress variations between grains and inside individual grains. A polycrystalline film when investigated at the granular (micron) level shows a highly mechanically inhomogeneous medium that allows insight into its mesoscopic properties. If the m-SXRD data are averaged over a macroscopic range, results show good agreement with direct macroscopic texture and stress measurements .

  12. Research and development of an electron beam focusing system for a high-brightness X-ray generator.

    Science.gov (United States)

    Sakai, Takeshi; Ohsawa, Satoshi; Sakabe, Noriyoshi; Sugimura, Takashi; Ikeda, Mitsuo

    2011-01-01

    A new type of rotating anticathode X-ray generator, where an electron beam of up to 60 keV irradiates the inner surface of a U-shaped Cu anticathode, has achieved a beam brilliance of 130 kW mm(-2) (at 2.3 kW). A higher-flux electron beam is expected from simulation by optimizing the geometry of a combined-function-type magnet instead of the fringing field of the bending magnet. In order to minimize the size of the X-ray source the electron beam has been focused over a short distance by a new combined-function bending magnet, whose geometrical shape was determined by simulation using the Opera-3D, General Particle Tracer and CST-STUDIO codes. The result of the simulation clearly shows that the role of combined functions in both the bending and the steering magnets is important for focusing the beam to a small size. FWHM sizes of the beam are predicted by simulation to be 0.45 mm (horizontal) and 0.05 mm (vertical) for a 120 keV/75 mA beam, of which the effective brilliance is about 500 kW mm(-2) on the supposition of a two-dimensional Gaussian distribution. High-power tests have begun using a high-voltage 120 kV/75 mA power supply for the X-ray generator instead of 60 kV/100 mA. The beam focus size on the target will be verified in the experiments.

  13. Evaluation of some selected vaccines and other biological products irradiated by gamma rays, electron beams and X-rays

    Energy Technology Data Exchange (ETDEWEB)

    May, J.C. E-mail: may@cber.fda.gov; Rey, L.; Lee, C.-J

    2002-03-01

    Molecular sizing potency results are presented for irradiated samples of one lot of Haemophilus b conjugate vaccine, pneumococcal polysaccharide type 6B and typhoid vi polysaccharide vaccine. The samples were irradiated (25 kGy) by gamma rays, electron beams and X-rays. IgG and IgM antibody response in mice test results (ELISA) are given for the Hib conjugate vaccine irradiated at 0 deg. C or frozen in liquid nitrogen.

  14. Interface characterization of B4C-based multilayers by X-ray grazing-incidence reflectivity and diffuse scattering.

    Science.gov (United States)

    Jiang, Hui; Wang, Zhanshan; Zhu, Jingtao

    2013-05-01

    B4C-based multilayers have important applications for soft to hard X-rays. In this paper, X-ray grazing-incidence reflectivity and diffuse scattering, combining various analysis methods, were used to characterize the structure of B4C-based multilayers including layer thickness, density, interfacial roughness, interdiffusion, correlation length, etc. Quantitative results for W/B4C, Mo/B4C and La/B4C multilayers were compared. W/B4C multilayers show the sharpest interfaces and most stable structures. The roughness replications of La/B4C and Mo/B4C multilayers are not strong, and oxidations and structure expansions are found in the aging process. This work provides guidance for future fabrication and characterization of B4C-based multilayers.

  15. Time-dependent, x-ray spectral unfolds and brightness temperatures for intense Li+ ion beam-driven hohlraums

    International Nuclear Information System (INIS)

    Fehl, D.L.; Chandler, G.A.; Biggs, F.; Dukart, R.J.; Moats, A.R.; Leeper, R.J.

    1997-01-01

    X-ray-producing hohlraums are being studied as indirect drives for inertial confinement fusion targets. In a 1994 target series on the PBFAII accelerator, cylindrical hohlraum targets were heated by an intense Li + ion beam and viewed by an array of 13 time-resolved, filtered x-ray detectors (XRDs). The unfold operator (UFO) code and its suite of auxiliary functions were used extensively in obtaining time-resolved x-ray spectra and radiation temperatures from this diagnostic. The UFO was also used to obtain fitted response functions from calibration data, to simulate data from blackbody x-ray spectra of interest, to determine the suitability of various unfolding parameters (e.g., energy domain, energy partition, smoothing conditions, and basis functions), to interpolate the XRD signal traces, and to unfold experimental data. The simulation capabilities of the code were useful in understanding an anomalous feature in the unfolded spectra at low photon energies (≤100 eV). Uncertainties in the differential and energy-integrated unfolded spectra were estimated from uncertainties in the data. The time endash history of the radiation temperature agreed well with independent calculations of the wall temperature in the hohlraum. copyright 1997 American Institute of Physics

  16. Time-dependent, x-ray spectral unfolds and brightness temperatures for intense Li+ ion beam-driven hohlraums

    International Nuclear Information System (INIS)

    Fehl, D.L.; Chandler, G.A.; Biggs, F.; Dukart, R.J.; Moats, A.R.; Leeper, R.J.

    1996-01-01

    X-ray-producing hohlraums are being studied as indirect drives for Inertial Confinement Fusion targets. In a 1994 target series on the PBFAII accelerator, cylindrical hohlraum targets were heated by an intense Li + ion beam and viewed by an array of 13 time-resolved, filtered x-ray detectors (XRDs). The UFO unfold code and its suite of auxiliary functions were used extensively in obtaining time- resolved x-ray spectra and radiation temperatures from this diagnostic. UFO was also used to obtain fitted response functions from calibration data, to simulate data from blackbody x-ray spectra of interest, to determine the suitability of various unfolding parameters (e.g., energy domain, energy partition, smoothing conditions, and basis functions), to interpolate the XRD signal traces, and to unfold experimental data. The simulation capabilities of the code were useful in understanding an anomalous feature in the unfolded spectra at low photon energies (≤ 100 eV). Uncertainties in the differential and energy-integrated unfolded spectra were estimated from uncertainties in the data. The time-history of the radiation temperature agreed well with independent calculations of the wall temperature in the hohlraum

  17. A Test Facility For Astronomical X-Ray Optics

    DEFF Research Database (Denmark)

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

    1989-01-01

    Grazing incidence x-ray optics for x-ray astronomical applications are used outside the earths atmosphere. These devices require a large collection aperture and the imaging of an x-ray source which is essentially placed at infinity. The ideal testing system for these optical elements has...... to approximate that encountered under working conditions, however the testing of these optical elements is notoriously difficult with conventional x-ray generators. Synchrotron Radiation (SR) sources are sufficiently brilliant to produce a nearly perfect parallel beam over a large area whilst still retaining...... a flux considerably higher than that available from conventional x-ray generators. A facility designed for the testing of x-ray optics, particularly in connection with x-ray telescopes is described below. It is proposed that this facility will be accommodated at the Synchrotron Radiation Source...

  18. A beam optics study of a modular multi-source X-ray tube for novel computed tomography applications

    Science.gov (United States)

    Walker, Brandon J.; Radtke, Jeff; Chen, Guang-Hong; Eliceiri, Kevin W.; Mackie, Thomas R.

    2017-10-01

    A modular implementation of a scanning multi-source X-ray tube is designed for the increasing number of multi-source imaging applications in computed tomography (CT). An electron beam array coupled with an oscillating magnetic deflector is proposed as a means for producing an X-ray focal spot at any position along a line. The preliminary multi-source model includes three thermionic electron guns that are deflected in tandem by a slowly varying magnetic field and pulsed according to a scanning sequence that is dependent on the intended imaging application. Particle tracking simulations with particle dynamics analysis software demonstrate that three 100 keV electron beams are laterally swept a combined distance of 15 cm over a stationary target with an oscillating magnetic field of 102 G perpendicular to the beam axis. Beam modulation is accomplished using 25 μs pulse widths to a grid electrode with a reverse gate bias of -500 V and an extraction voltage of +1000 V. Projected focal spot diameters are approximately 1 mm for 138 mA electron beams and the stationary target stays within thermal limits for the 14 kW module. This concept could be used as a research platform for investigating high-speed stationary CT scanners, for lowering dose with virtual fan beam formation, for reducing scatter radiation in cone-beam CT, or for other industrial applications.

  19. Exploring vacuum birefringence based on a 100 PW laser and an x-ray free electron laser beam

    Science.gov (United States)

    Shen, Baifei; Bu, Zhigang; Xu, Jiancai; Xu, Tongjun; Ji, Liangliang; Li, Ruxin; Xu, Zhizhan

    2018-04-01

    Exploring vacuum birefringence with the station of extreme light at Shanghai Coherent Light Facility is considered. Laser pulses of intensity beyond 1023 W cm-2 are capable of polarizing the vacuum due to the ultra-strong electro-magnetic fields. The subtle difference of the vacuum refractive indexes along electric and magnetic fields leads to a birefringence effect for lights propagating through. The vacuum birefringence effect can now be captured by colliding a hard x-ray free electron laser (XFEL) beam with a high-power laser. The initial XFEL beam of pure linear polarization is predicated to gain a very small ellipticity after passing through the laser stimulated vacuum. Various interaction geometries are considered, showing that the estimated ellipticity lies between 1.8 × 10-10 and 10-9 for a 100 PW laser interacting with a 12.9 keV XFEL beam, approaching the threshold for todays’ polarity detection technique. The detailed experimental set-up is designed, including the polarimeter, the focusing compound refractive lens and the optical path. When taking into account the efficiencies of the x-ray instruments, it is found that about 10 polarization-flipped x-ray photons can be detected for a single shot for our design. Considering the background noise level, accumulating runs are necessary to obtain high confident measurement.

  20. On the radiation beaming of bright X-ray pulsars and constraints on neutron star mass-radius relation

    Science.gov (United States)

    Mushtukov, Alexander A.; Verhagen, Patrick A.; Tsygankov, Sergey S.; van der Klis, Michiel; Lutovinov, Alexander A.; Larchenkova, Tatiana I.

    2018-03-01

    The luminosity of accreting magnetized neutron stars can largely exceed the Eddington value due to appearance of accretion columns. The height of the columns can be comparable to the neutron star radius. The columns produce the X-rays detected by the observer directly and illuminate the stellar surface, which reprocesses the X-rays and causes additional component of the observed flux. The geometry of the column and the illuminated part of the surface determine the radiation beaming. Curved space-time affects the angular flux distribution. We construct a simple model of the beam patterns formed by direct and reflected flux from the column. We take into account the possibility of appearance of accretion columns, whose height is comparable to the neutron star radius. We argue that depending on the compactness of the star, the flux from the column can be either strongly amplified due to gravitational lensing, or significantly reduced due to column eclipse by the star. The eclipses of high accretion columns result in specific features in pulse profiles. Their detection can put constraints on the neutron star radius. We speculate that column eclipses are observed in X-ray pulsar V 0332+53, leading us to the conclusion of large neutron star radius in this system (˜15 km if M ˜ 1.4 M⊙). We point out that the beam pattern can be strongly affected by scattering in the accretion channel at high luminosity, which has to be taken into account in the models reproducing the pulse profiles.

  1. Is low-energy-ion bombardment generated X-ray emission a secondary mutational source to ion-beam-induced genetic mutation?

    International Nuclear Information System (INIS)

    Thongkumkoon, P.; Prakrajang, K.; Thopan, P.; Yaopromsiri, C.; Suwannakachorn, D.; Yu, L.D.

    2013-01-01

    Highlights: ► Detected X-ray emission from metal, plastic and biological samples. ► Characteristic X-ray emission was detected from metal but not from non-metals. ► Low-energy ion bombarded bacteria held in different sample holders. ► Bacteria held in metal holder had higher mutation rate than in plastic holder. ► Ion-beam-induced X-ray from biological sample is not a basic mutation source. -- Abstract: Low-energy ion beam biotechnology has achieved tremendous successes in inducing crop mutation and gene transfer. However, mechanisms involved in the related processes are not yet well understood. In ion-beam-induced mutation, ion-bombardment-produced X-ray has been proposed to be one of the secondary mutation sources, but the speculation has not yet been experimentally tested. We carried out this investigation to test whether the low-energy ion-beam-produced X-ray was a source of ion-beam-induced mutation. In the investigation, X-ray emission from 29-keV nitrogen- or argon- ion beam bombarded bacterial Escherichia coli (E. coli) cells held in a metal or plastic sample holder was in situ detected using a highly sensitive X-ray detector. The ion beam bombarded bacterial cells held in different material holders were observed for mutation induction. The results led to a conclusion that secondary X-ray emitted from ion-beam-bombarded biological living materials themselves was not a, or at least a negligible, mutational source, but the ion-beam-induced X-ray emission from the metal that made the sample holder could be a source of mutation

  2. Is low-energy-ion bombardment generated X-ray emission a secondary mutational source to ion-beam-induced genetic mutation?

    Energy Technology Data Exchange (ETDEWEB)

    Thongkumkoon, P. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand); Prakrajang, K. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Faculty of Science, Maejo University, Chiang Mai 50290 (Thailand); Thopan, P.; Yaopromsiri, C. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Suwannakachorn, D. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand); Yu, L.D., E-mail: yuld@fnrf.science.cmu.ac.th [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand)

    2013-07-15

    Highlights: ► Detected X-ray emission from metal, plastic and biological samples. ► Characteristic X-ray emission was detected from metal but not from non-metals. ► Low-energy ion bombarded bacteria held in different sample holders. ► Bacteria held in metal holder had higher mutation rate than in plastic holder. ► Ion-beam-induced X-ray from biological sample is not a basic mutation source. -- Abstract: Low-energy ion beam biotechnology has achieved tremendous successes in inducing crop mutation and gene transfer. However, mechanisms involved in the related processes are not yet well understood. In ion-beam-induced mutation, ion-bombardment-produced X-ray has been proposed to be one of the secondary mutation sources, but the speculation has not yet been experimentally tested. We carried out this investigation to test whether the low-energy ion-beam-produced X-ray was a source of ion-beam-induced mutation. In the investigation, X-ray emission from 29-keV nitrogen- or argon- ion beam bombarded bacterial Escherichia coli (E. coli) cells held in a metal or plastic sample holder was in situ detected using a highly sensitive X-ray detector. The ion beam bombarded bacterial cells held in different material holders were observed for mutation induction. The results led to a conclusion that secondary X-ray emitted from ion-beam-bombarded biological living materials themselves was not a, or at least a negligible, mutational source, but the ion-beam-induced X-ray emission from the metal that made the sample holder could be a source of mutation.

  3. Providing x-rays

    International Nuclear Information System (INIS)

    Mallozzi, P.J.; Epstein, H.M.

    1985-01-01

    This invention provides an apparatus for providing x-rays to an object that may be in an ordinary environment such as air at approximately atmospheric pressure. The apparatus comprises: means (typically a laser beam) for directing energy onto a target to produce x-rays of a selected spectrum and intensity at the target; a fluid-tight enclosure around the target; means for maintaining the pressure in the first enclosure substantially below atmospheric pressure; a fluid-tight second enclosure adjoining the first enclosure, the common wall portion having an opening large enough to permit x-rays to pass through but small enough to allow the pressure reducing means to evacuate gas from the first enclosure at least as fast as it enters through the opening; the second enclosure filled with a gas that is highly transparent to x-rays; the wall of the second enclosure to which the x-rays travel having a portion that is highly transparent to x-rays (usually a beryllium or plastic foil), so that the object to which the x-rays are to be provided may be located outside the second enclosure and adjacent thereto and thus receive the x-rays substantially unimpeded by air or other intervening matter. The apparatus is particularly suited to obtaining EXAFS (extended x-ray fine structure spectroscopy) data on a material

  4. Accuracy of cranial coplanar beam therapy using an oblique, stereoscopic x-ray image guidance system

    International Nuclear Information System (INIS)

    Vinci, Justin P.; Hogstrom, Kenneth R.; Neck, Daniel W.

    2008-01-01

    A system for measuring two-dimensional (2D) dose distributions in orthogonal anatomical planes in the cranium was developed and used to evaluate the accuracy of coplanar conformal therapy using ExacTrac image guidance. Dose distributions were measured in the axial, sagittal, and coronal planes using a CIRS (Computerized Imaging Reference Systems, Inc.) anthropomorphic head phantom with a custom internal film cassette. Sections of radiographic Kodak EDR2 film were cut, processed, and digitized using custom templates. Spatial and dosimetric accuracy and precision of the film system were assessed. BrainScan planned a coplanar-beam treatment to conformally irradiate a 2-cm-diameterx2-cm-long cylindrical planning target volume. Prior to delivery, phantom misalignments were imposed in combinations of ±8 mm offsets in each of the principal directions. ExacTrac x-ray correction was applied until the phantom was within an acceptance criteria of 1 mm/1 deg. (first two measurement sets) or 0.4 mm/0.4 deg. (last two measurement sets). Measured dose distributions from film were registered to the treatment plan dose calculations and compared. Alignment errors, displacement between midpoints of planned and measured 70% isodose contours (Δc), and positional errors of the 80% isodose line were evaluated using 49 2D film measurements (98 profiles). Comparison of common, but independent measurements of Δc showed that systematic errors in the measurement technique were 0.2 mm or less along all three anatomical axes and that random error averaged (σ±σ σ ) 0.29±0.06 mm for the acceptance criteria of 1 mm/1 deg. and 0.15±0.02 mm for the acceptance criteria of 0.4 mm/0.4 deg. . The latter was consistent with independent estimates that showed the precision of the measurement system was 0.3 mm (2σ). Values of Δc were as great as 0.9, 0.3, and 1.0 mm along the P-A, R-L, and I-S axes, respectively. Variations in Δc along the P-A axis were correlated to misalignments between laser

  5. Measurement of position dependence of spectral distribution in primary X-ray beam of CT system using compton spectroscopy

    International Nuclear Information System (INIS)

    Matsumoto, Masao; Maeda, Koji; Maeda, Koji

    2005-01-01

    Our purpose is to acquire the diagnostic x-ray spectra of the CT system easily under clinical conditions by Compton scatter spectroscopy using a high resolution Schottky CdTe detector recently developed and to estimate the quality and quantity of these spectra compared the relative exposure measured using an ionization chamber with curves measured by the reconstructed spectra. Although the spectral broadening and the fluctuation were slightly shown, the errors of the relative exposure were under 10%. Though the experimental arrangement of this method is so easy and reconstructed algorithm is simple, these results suggested that this method is little influenced by the variation of dose rates or property of the incident x rays. We therefore propose that the Compton scatter spectroscopy with the newly developed Schottky CdTe detector is suitable for measuring the diagnostic x-ray spectra of the CT system under the clinical conditions and useful for quality assurance and quality control of the clinical x-ray CT system. (author)

  6. On diamond windows for high power synchrotron x-ray beams

    International Nuclear Information System (INIS)

    Khounsary, A.M.; Kuzay, T.M.

    1991-01-01

    Recent advances in chemical vapor deposition (CVD) technology has made available thin, free-standing polycrystalline diamond foils that can be used as the window material on high heat load synchrotron x-ray beamlines. Diamond windows have many advantages that stem from the exceptionally attractive thermal, structural, and physical properties of diamond. Numerical simulations indicate that diamond windows can offer an attractive and at times the only alternative to beryllium windows for use on the third generation x-ray synchrotron radiation beamlines. Utilization, design, and fabrication aspects of diamond windows for high heat load x-ray beamlines are discussed, and analytical and numerical results are presented to provide a basis for the design and testing of such windows

  7. Evaluation device of diagnostic X-ray beam; Analisador de feixe de raios-X diagnostico

    Energy Technology Data Exchange (ETDEWEB)

    Pela, Carlos Alberto; Paula, Eldereis de; Bruco, Jose Luiz; Ghilardi Netto, Thomaz [Sao Paulo Univ., Ribeirao Preto, SP (Brazil). Faculdade de Filosofia, Ciencias e Letras. CIDRA

    1996-12-31

    A device developed to determine the physical parameters useful to the evaluation of both dental and medical X-ray equipment is presented. Nine detectors connected each one to a signal amplifier are used. The amplifiers output has being connected to an analog to digital interface plugged in a PC-AT microcomputer. The X-ray pass through filters before reaching the detectors. The data collected by microcomputer are used to calculate the kVp and other factors as total tube filtration, waveform, half-value layer, exposure rate and exposure time 4 tabs.

  8. Quantitative determination of phases of X-ray reflections from three-beam diffractions. Pt. 2

    International Nuclear Information System (INIS)

    Tang Mautsu; Chang Shihlin

    1988-01-01

    The method proposed by Chang and Tang of quantitative determination of X-ray reflection phases from multiple diffraction profiles is applied to nearly perfect crystals of gallium arsenide. The detailed intensity-profile-analysis procedures are given. Multiple diffraction profiles obtained with a conventional X-ray source and synchrotron radiation are subjected to this analysis. It is found that, for this particular diffraction example, errors as small as 15 0 in phase determination are achieved. Errors due to the theoretical approximation, peak position measurement and scaling factor are also discussed. (orig.)

  9. Precision scans of the Pixel cell response of double sided 3D Pixel detectors to pion and X-ray beams

    CERN Document Server

    Mac Raighne, A; Crossley, M; Alianelli, L; Lozano, M; Dumps, R; Fleta, C; Collins, P; Rodrigues, E; Sawhney, K J S; Tlustos, L; Pennicard, D; Buytaert, J; Stewart, G; Parkes, C; Eklund, L; Campbell, M; Marchal, J; Akiba, K; Pellegrini, G; Llopart, X; Plackett, R; Maneuski, D; Gligorov, V V; Tartoni, N; Nicol, M; Bates, R; Gallas, A; Gimenez, E N; van Beuzekom, M; John, M

    2011-01-01

    Three-dimensional (3D) silicon sensors offer potential advantages over standard planar sensors for radiation hardness in future high energy physics experiments and reduced charge-sharing for X-ray applications, but may introduce inefficiencies due to the columnar electrodes. These inefficiencies are probed by studying variations in response across a unit pixel cell in a 55 m m pitch double-sided 3D pixel sensor bump bonded to TimePix and Medipix2 readout ASICs. Two complementary characterisation techniques are discussed: the first uses a custom built telescope and a 120GeV pion beam from the Super Proton Synchrotron (SPS) at CERN; the second employs a novel technique to illuminate the sensor with a micro-focused synchrotron X-ray beam at the Diamond Light Source, UK. For a pion beam incident perpendicular to the sensor plane an overall pixel efficiency of 93.0 +/- 0.5\\% is measured. After a 10 degrees rotation of the device the effect of the columnar region becomes negligible and the overall efficiency rises ...

  10. An extended range soft X-ray beam line for the 1 GeV storage ring Aladdin

    International Nuclear Information System (INIS)

    Hulbert, S.L.; Stott, J.P.; Brown, F.C.

    1983-01-01

    The design and implementation of a soft X-ray beam line on the new 1 GeV storage ring Aladdin in Stoughton, Wisconsin is discussed. The beam line consists of a long horizontally focussing collection mirror, an extended range (50-1500 eV) grasshopper monochromator, an ellipsoidal refocussing mirror, and a photoemission chamber. Also discussed are the factors considered in matching the monochromator to the storage ring, flux and performance expectations, and the results of a ray tracing analysis. (orig.)

  11. Soft X-ray generation via inverse compton scattering between high quality electron beam and high power laser

    International Nuclear Information System (INIS)

    Masakazu Washio; Kazuyuki Sakaue; Yoshimasa Hama; Yoshio Kamiya; Tomoko Gowa; Akihiko Masuda; Aki Murata; Ryo Moriyama; Shigeru Kashiwagi; Junji Urakawa

    2007-01-01

    High quality beam generation project based on High-Tech Research Center Project, which has been approved by Ministry of Education, Culture, Sports, Science and Technology in 1999, has been conducted by advance research institute for science and engineering, Waseda University. In the project, laser photo-cathode RF-gun has been selected for the high quality electron beam source. RF cavities with low dark current, which were made by diamond turning technique, have been successfully manufactured. The low emittance electron beam was realized by choosing the modified laser injection technique. The obtained normalized emmitance was about 3 m.mrad at 100 pC of electron charge. The soft x-ray beam generation with the energy of 370 eV, which is in the energy region of so-called water window, by inverse Compton scattering has been performed by the collision between IR laser and the low emmitance electron beams. (Author)

  12. Intense microfocus X-ray source

    International Nuclear Information System (INIS)

    Parish, R.W.

    1984-01-01

    An intense microfocus X-ray source comprises a chamber, a turbomolecular pump to evacuate the chamber, an anode and a cathode within the chamber and electromagnet coils to focus electrons from the cathode on to a small spot on the anode to produce a divergent X-ray beam. The pump has a shaft to which the anode is connected, so that operation of the pump causes rotation of the anode. Heat generated in the anode by the incident electron beam is spread over a larger area than if the anode were stationary. Consequently a more intense electron beam can be used, leading to a more intense X-ray beam, without melting the anode. (author)

  13. The techniques of investigation of works of art: ion-beam accelerator and x-ray radiography

    International Nuclear Information System (INIS)

    Dupouy, Jean-Michel

    1996-01-01

    X-rays are essential for the museum laboratory because they give rise to three types of techniques which are currently used, the radiography, the diffraction and the elemental analyses based on the characteristic emission. They have been at the origin of the creation of this type of laboratories throughout the world. Radiography brings unique information on the present condition of the works of art and on the techniques which have been used to make them. Its indiscreet glance often sheds a new light on the gesture or the thought process of the artist. The information they give on the evolution of the artefacts since their creation are also essential to ensure their restoration and their conservation. The elemental analyses, some of which are also based on the characteristic x-ray emission allow to investigate not only the fabrication techniques but also the provenances and the state of preservation. A tandem ion beam accelerator has been installed in the Louvre to increase the analytical potential of the laboratory. It gives access to the three main ion beam analysis techniques, proton induced x-ray emission (PIXE), Rutherford Backscattering Spectrometry (RBS) and Nuclear Reaction Analysis (NRA). Numerous examples taken from the work at the laboratory of the French museums illustrate these applications. (author). 18 refs., 33 figs

  14. Measured and Monte Carlo simulated surface dose reduction for superficial X-rays incident on tissue with underlying air or bone.

    Science.gov (United States)

    Baines, John; Zawlodzka, Sylwia; Markwell, Tim; Chan, Millicent

    2018-02-01

    Measurement of surface dose reduction effects for superficial x-rays incident on tissue with underlying air or bone and comparison with Monte Carlo simulations of such effects. Further to investigate the correlation between surface dose reduction and changes in Compton backscatter spectra with tissue-bone separation. An Advanced Markus chamber with entrance window facing downstream on the surface of a solid water phantom was used to investigate changes in surface dose with an underlying air or bone interface located at various depths below the surface. Chamber readings were obtained for interface depths ranging from 1 to 100 mm using the 50 kV, 100 kV and 150 kV beams of an Xstrahl 150 x-ray unit, with field diameters (ϕ) = 2.5 cm and 5 cm. For each beam quality and field size the dose correction factor, DCF(t), namely the ratio of measured dose (t) to dose (t = 100 mm) was determined. Monte Carlo simulations of DCF(t) for air and bone interfaces in tissue are used to validate corresponding measured data. For a given beam and field size, the difference between simulated spectra with an air or bone interface at t = 3 mm was used to determine the Compton backscatter from bone at the surface. For air, DCF(t tube potentials corresponding factors, ϕ = 2.5 cm, for air(bone) are 0.94(0.96) and 0.92(0.99). Calculated DCF(t) based on Monte Carlo simulations are consistent with experimental observations to within 2%. Monte Carlo simulations of x-ray spectra demonstrate the presence of Compton backscatter from underlying bone in tissue. With bone at 3 mm depth calculated backscatter spectra at the tissue surface suggest that surface dose is influenced by the proximity of bone and that this effect depends on beam quality. This work demonstrates the feasibility of using an Advanced Markus chamber with entrance window facing downstream to investigate surface dose reduction with underlying air or bone in tissue. As the field size decreases and beam quality increases surface

  15. Tunable X-ray source

    Science.gov (United States)

    Boyce, James R [Williamsburg, VA

    2011-02-08

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

  16. Analysis of the procedures and criteria for implantation of X-ray beams for ISO 4037 reference at low energies

    International Nuclear Information System (INIS)

    Figueiredo, Marcus Tadeu Tanuri de

    2012-01-01

    According to the radiological protection principles, practices involving ionizing radiation must be planned and carried out under the guarantee that the values of individual doses, the number of people exposed to radiation and the probability of accidental exposures are as low as reasonably achievable. Therefore, radiation dosimetry is required to be done with reliable instruments designed for measuring dosimetric quantities. The reliability of the dosimetry depends on both the calibration of the dosimeter and its proper performance under certain test conditions. The International Standardization Organization (ISO), in order to promote international standardization and metrological coherency, established sets of reference X-ray beams for dosimeter calibration and typing-test; they are expected to be implemented in metrology laboratories in compliance with specific technical requirements. At low energies there are specific requirements that need to be considered in both the implementation of the reference beams and their use in calibration and testing. The present study is an analysis of the procedures and criteria for ISO 4037 reference radiation implementation, at low energies. In the Dosimeter Calibration Laboratory of the Development Center of Nuclear Technology (LCD / CDTN), experiments were performed for determining the X-ray reference radiation parameters. Alternatives to the usual methods for half-value layer determination were studied. Spectra of reference beams were simulated with software and compared with experimental measurements. Different climatic conditions were reproduced in the Laboratory for analysis of its influence on the determination of the beam parameters. Uncertainties in the measurements of studied parameters were evaluated. According to the ISO 4037 criteria, the low energy X-ray beams were considered to be implemented; they allowed the determination of the conversion coefficients from air kerma to the operational radiation protection

  17. New x-ray parallel beam facility XPBF 2.0 for the characterization of silicon pore optics

    Science.gov (United States)

    Krumrey, Michael; Müller, Peter; Cibik, Levent; Collon, Max; Barrière, Nicolas; Vacanti, Giuseppe; Bavdaz, Marcos; Wille, Eric

    2016-07-01

    A new X-ray parallel beam facility (XPBF 2.0) has been installed in the laboratory of the Physikalisch-Technische Bundesanstalt at the synchrotron radiation facility BESSY II in Berlin to characterize silicon pore optics (SPOs) for the future X-ray observatory ATHENA. As the existing XPBF which is operated since 2005, the new beamline provides a pencil beam of very low divergence, a vacuum chamber with a hexapod system for accurate positioning of the SPO to be investigated, and a vertically movable CCD-based camera system to register the direct and the reflected beam. In contrast to the existing beamline, a multilayer-coated toroidal mirror is used for beam monochromatization at 1.6 keV and collimation, enabling the use of beam sizes between about 100 μm and at least 5 mm. Thus the quality of individual pores as well as the focusing properties of large groups of pores can be investigated. The new beamline also features increased travel ranges for the hexapod to cope with larger SPOs and a sample to detector distance of 12 m corresponding to the envisaged focal length of ATHENA.

  18. Gamma-H2AX foci in cells exposed to a mixed beam of X-rays and alpha particles

    Science.gov (United States)

    2012-01-01

    Background Little is known about the cellular effects of exposure to mixed beams of high and low linear energy transfer radiation. So far, the effects of combined exposures have mainly been assessed with clonogenic survival or cytogenetic methods, and the results are contradictory. The gamma-H2AX assay has up to now not been applied in this context, and it is a promising tool for investigating the early cellular response to mixed beam irradiation. Purpose To determine the dose response and repair kinetics of gamma-H2AX ionizing radiation-induced foci in VH10 human fibroblasts exposed to mixed beams of 241Am alpha particles and X-rays. Results VH10 human fibroblasts were irradiated with each radiation type individually or both in combination at 37°C. Foci were scored for repair kinetics 0.5, 1, 3 and 24 h after irradiation (one dose per irradiation type), and for dose response at the 1 h time point. The dose response effect of mixed beam was additive, and the relative biological effectiveness for alpha particles (as compared to X-rays) was of 0.76 ± 0.52 for the total number of foci, and 2.54 ± 1.11 for large foci. The repair kinetics for total number of foci in cells exposed to mixed beam irradiation was intermediate to that of cells exposed to alpha particles and X-rays. However, for mixed beam-irradiated cells the frequency and area of large foci were initially lower than predicted and increased during the first 3 hours of repair (while the predicted number and area did not). Conclusions The repair kinetics of large foci after mixed beam exposure was significantly different from predicted based on the effect of the single dose components. The formation of large foci was delayed and they did not reach their maximum area until 1 h after irradiation. We hypothesize that the presence of low X-ray-induced damage engages the DNA repair machinery leading to a delayed DNA damage response to the more complex DNA damage induced by alpha particles. PMID:23121736

  19. Development of an x-ray beam line at the NSLS for studies in materials science using x-ray absorption spectroscopy. Progress report

    International Nuclear Information System (INIS)

    Sayers, D.E.

    1985-01-01

    This has been an exciting year for our PRT, highlighted by the running of the NSLS x-ray ring in an operational mode beginning in May of this year. Our line X-11A was the first to obtain an experimental spectrum and the first to publish a paper with results from the x-ray ring. These early successes have allowed us to run in an operational mode during the entire time that the x-raying ring itself has been operational. In addition to a number of exciting initial scientific results described, the initial results, particularly in the four crystal mode, have verified our original optical design and demonstrated an improved resolution using the four crystals. This will have a significant impact on near edge (XANES) studies

  20. X-ray detector array

    International Nuclear Information System (INIS)

    Houston, J.M.

    1980-01-01

    The object of the invention (an ionization chamber X-ray detector array for use with high speed computerised tomographic imaging apparatus) is to reduce the time required to produce a tomographic image. The detector array described determines the distribution of X-ray intensities in one or more flat, coplanar X-ray beams. It comprises three flat anode sheets parallel to the X-ray beam, a plurality of rod-like cathodes between the anodes, a detector gas between the electrodes and a means for applying a potential between the electrodes. Each of the X-ray sources is collimated to give a narrow, planar section of X-ray photons. Sets of X-ray sources in the array are pulsed simultaneously to obtain X-ray transmission data for tomographic image reconstruction. (U.K.)

  1. Electron beam produced in a transient hollow cathode discharge: beam electron distribution function, X-ray emission and solid target ablation

    International Nuclear Information System (INIS)

    Nistor, Magdalena

    2000-01-01

    This research thesis aims at a better knowledge of phenomena occurring during transient hollow cathode discharges. The author first recalls the characteristics of such a discharge which make it different from conventional pseudo-spark discharges. The objective is to characterise the electron beam produced within the discharge, and the phenomena associated with its interaction with a solid or gaseous target, leading to the production of an X ray or visible radiation. Thus, the author reports the measurement (by magnetic deflection) of the whole time-averaged electronic distribution function. Such a knowledge is essential for a better use of the electron beam in applications such as X-ray source or material ablation. As high repetition frequency pulse X ray sources are very interesting tools, he reports the development and characterisation of Bremsstrahlung X rays during a beam-target interaction. He finally addresses the implementation of a spectroscopic diagnosis for the filamentary plasma and the ablation of a solid target by the beam [fr

  2. Comparison between beam-stop and beam-hole array scatter correction techniques for industrial X-ray cone-beam CT

    Energy Technology Data Exchange (ETDEWEB)

    Schoerner, K., E-mail: karsten.schoerner.ext@siemens.co [Corporate Technology, Siemens AG, 81739 Muenchen (Germany); Physik-Department, Technische Universitaet Muenchen, 85748 Garching (Germany); Goldammer, M.; Stephan, J. [Corporate Technology, Siemens AG, 81739 Muenchen (Germany)

    2011-02-01

    Research highlights: {yields} We propose a scatter correction method employing a beam-hole array. {yields} Beam-hole and beam-stop array techniques are compared in respect of geometric and scattering properties. {yields} The beam-hole array method reduces overall scattering compared to a beam-stop array. {yields} Application of the beam-hole array method is successfully demonstrated for a CT of ceramic specimen. -- Abstract: In industrial X-ray cone-beam computed tomography, the inspection of large-scale samples is important because of increasing demands on their quality and long-term mechanical resilience. Large-scale samples, for example made of aluminum or iron, are strongly scattering X-rays. Scattered radiation leads to artifacts such as cupping, streaks, and a reduction in contrast in the reconstructed CT-volume. We propose a scatter correction method based on sampling primary signals by employing a beam-hole array (BHA). In this indirect method, a scatter estimate is calculated by subtraction of the sampled primary signal from the total signal, the latter taken from an image where the BHA is absent. This technique is considered complementary to the better known beam-stop array (BSA) method. The two scatter estimation methods are compared here with respect to geometric effects, scatter-to-total ratio and practicability. Scatter estimation with the BHA method yields more accurate scatter estimates in off-centered regions, and a lower scatter-to-total ratio in critical image regions where the primary signal is very low. Scatter correction with the proposed BHA method is then applied to a ceramic specimen from power generation technologies. In the reconstructed CT volume, cupping almost completely vanishes and contrast is enhanced significantly.

  3. Anomalous grazing incidence small-angle x-ray scattering studies of Pt nanoparticles formed by cluster deposition

    International Nuclear Information System (INIS)

    Lee, B.; Seifert, S.; Riley, S.J.; Tikhonov, G.Y.; Tomczyk, N.A.; Vajda, S.; Winans, R.E.

    2005-01-01

    The size evolution of platinum nanoparticles formed on a SiO2/Si(111) substrate as a function of the level of surface coverage with deposited clusters has been investigated. The anisotropic shapes of sub-nanometer-size nanoparticles are changed to isotropic on the amorphous substrate as their sizes increased. Using anomalous grazing incidence small-angle x-ray scattering (AGISAXS), the scattering from nanoparticles on the surface of a substrate is well separated from that of surface roughness and fluorescence. We show that AGISAXS is a very effective method to subtract the background and can provide unbiased information about particle sizes of less than 1 nm.

  4. Intercomparison of ionization chambers in standard X-ray beams, at radiotherapy, diagnostic radiology and radioprotection levels

    International Nuclear Information System (INIS)

    Bessa, Ana Carolina Moreira de

    2007-01-01

    Since the calibration of radiation measurement instruments and the knowledge of their major characteristics are very important subjects, several different types of ionization chambers were inter compared in terms of their calibration coefficients and their energy dependence, in radiotherapy, diagnostic radiology and radioprotection standard beams. An intercomparison of radionuclide calibrators for nuclear medicine was performed, using three radionuclides: 67 Ga, 201 Tl and 99m Tc; the results obtained were all within the requirements of the national standard CNEN-NE-3.05. In order to complete the range of radiation qualities of the Calibration Laboratory of IPEN, standard radiation beam qualities, radiation protection and low energy radiation therapy levels, were established, according international recommendations. Three methodologies for the calibration of unsealed ionization chambers in X-ray beams were studied and compared. A set of Victoreen ionization chambers, specially designed for use in laboratorial intercomparisons, was submitted to characterization tests. The performance of these Victoreen ionization chambers showed that they are suitable for use in radioprotection beams, because the results obtained agree with international recommendations. However, these Victoreen ionization chambers can be used in radiotherapy and diagnostic radiology beams only with some considerations, since their performance in these beams, especially in relation to the energy dependence and stabilization time tests, did not agree with the international recommendations for dosimeters used in radiotherapy and diagnostic radiology beams. This work presents data on the performance of several types of ionization chambers in different X-ray beams, that may be useful for choosing the appropriate instrument for measurements in ionizing radiation beams. (author)

  5. Grazing incidence X-ray fluorescence analysis of buried interfaces in periodically structured crystalline silicon thin-film solar cells

    International Nuclear Information System (INIS)

    Eisenhauer, David; Preidel, Veit; Becker, Christiane; Pollakowski, Beatrix; Beckhoff, Burkhard; Baumann, Jonas; Kanngiesser, Birgit; Amkreutz, Daniel; Rech, Bernd; Back, Franziska; Rudigier-Voigt, Eveline

    2015-01-01

    We present grazing incidence X-ray fluorescence (GIXRF) experiments on 3D periodically textured interfaces of liquid phase crystallized silicon thin-film solar cells on glass. The influence of functional layers (SiO x or SiO x /SiC x ) - placed between glass substrate and silicon during crystallization - on the final carbon and oxygen contaminations inside the silicon was analyzed. Baring of the buried structured silicon surface prior to GIXRF measurement was achieved by removal of the original nano-imprinted glass substrate by wet-chemical etching. A broad angle of incidence distribution was determined for the X-ray radiation impinging on this textured surface. Optical simulations were performed in order to estimate the incident radiation intensity on the structured surface profile considering total reflection and attenuation effects. The results indicate a much lower contamination level for SiO x compared to the SiO x /SiC x interlayers, and about 25% increased contamination when comparing structured with planar silicon layers, both correlating with the corresponding solar cell performances. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Semi-empirical procedures for correcting detector size effect on clinical MV x-ray beam profiles

    International Nuclear Information System (INIS)

    Sahoo, Narayan; Kazi, Abdul M.; Hoffman, Mark

    2008-01-01

    The measured radiation beam profiles need to be corrected for the detector size effect to derive the real profiles. This paper describes two new semi-empirical procedures to determine the real profiles of high-energy x-ray beams by removing the detector size effect from the measured profiles. Measured profiles are corrected by shifting the position of each measurement point by a specific amount determined from available theoretical and experimental knowledge in the literature. The authors developed two procedures to determine the amount of shift. In the first procedure, which employs the published analytical deconvolution procedure of other investigators, the shift is determined from the comparison of the analytical fit of the measured profile and the corresponding analytical real profile derived from the deconvolution of the fitted measured profile and the Gaussian detector response function. In the second procedure, the amount of shift at any measurement point is considered to be proportional to the value of an analytical function related to the second derivative of the real profile at that point. The constant of proportionality and a parameter in the function are obtained from the values of the shifts at the 90%, 80%, 20%, and 10% dose levels, which are experimentally known from the published results of other investigators to be approximately equal to half of the radius of the detector. These procedures were tested by correcting the profiles of 6 and 18 MV x-ray beams measured by three different ionization chambers and a stereotactic field diode detector with 2.75, 2, 1, and 0.3 mm radii of their respective active cylindrical volumes. The corrected profiles measured by different detectors are found to be in close agreement. The detector size corrected penumbra widths also agree with the expected values based on the results of an earlier investigation. Thus, the authors concluded that the proposed procedures are accurate and can be used to derive the real

  7. Characterization of a free-air ionization chamber in direct X-ray beams as used in mammography

    International Nuclear Information System (INIS)

    Lima, Mateus Hilario de

    2014-01-01

    At this work stability and characterization tests were undertaken on a Victoreen free-air ionization chamber, model 481. The tests were realized using direct X-ray beams as a contribution for its establishment as a primary standard system of the quantity air kerma. The characterization tests were: saturation curve, ion collection efficiency, polarity effect, response linearity with the air kerma rate and response linearity with the chamber volume variation. The ion collection efficiency allowed the determination of the ion recombination factor. Most of the test results showed agreement with the limits established by international standards. Furthermore, the air attenuation factors for the mammography beams with aluminum and molybdenum filters were obtained. The factors for photon transmission and scattering at the diaphragm edges were also determined for mammography beams with aluminum filter and for the standard beam with molybdenum filter. (author)

  8. The development of a postal method to assess X-ray beam parameters and image quality in dental radiology

    International Nuclear Information System (INIS)

    Fenton, D.M.

    1994-10-01

    Intraoral radiographs are an extremely valuable diagnostic tool in dentistry. Radiography permits the early detection and diagnosis of dental disease and consequently is used extensively. However, public concern about radiation exposure has increased in recent times. This concern is reflected in national and international law, to the extent that, the basic principles of radiological protection, that is, justification, optimisation and dose limitation are written into law. Furthermore, in Ireland, the regulations, as outlined in the Code of Practice for Radiological Protection in Dentistry, require intraoral dental X-ray machines to perform to certain standards. A report of a direct survey of 164 intraoral dental X-ray machines is given in this study. The survey covered mechanical, electrical as well as radiation safety. Inadequacies with respect to focus to skin distance and timer accuracy were found in 45% and 42% of the machines surveyed. Ninety eight machines were assessed for electrical safety in which 48% were found to be unsafe. The results indicate that a complete assessment of the performance of dental X-ray units in Ireland is required. However, as there are in excess of 800 dental X-ray machines located throughout the country, such an assessment would be very costly for the regulatory authority. The development of a postal method for the assessment of the performance of dental X-ray machines is described in this study. This postal method provides information on the kV, total filtration, beam width and timer linearity and is undertaken by means of a penetrameter and film envelopes for exposure to the X-ray set under examination, together with a questionnaire that requests information on environment in which the machine is located. Using this method an accuracy of +-5% of the actual value was achieved in the measurement of kVp. The penetrameter was also used to assess whether or not the filtration of a particular machine complies with the regulations. This

  9. Aberration-free laser beam in the soft x-ray range

    Czech Academy of Sciences Publication Activity Database

    Goddet, J.P.; Sebban, S.; Gautier, J.; Zeitoun, P.; Valentin, C.; Tissandier, F.; Marchenko, T.; Lambert, G.; Ribières, M.; Douillet, D.; Lefrou, T.; Iaquaniello, G.; Burgy, F.; Maynard, G.; Cros, B.; Robillard, B.; Mocek, Tomáš; Nejdl, Jaroslav; Kozlová, Michaela; Jakubczak, Krzysztof

    2009-01-01

    Roč. 34, č. 16 (2009), 2438-24 ISSN 0146-9592 R&D Projects: GA ČR GC202/07/J008 Grant - others:AV ČR(CZ) M100100911 Institutional research plan: CEZ:AV0Z10100523 Keywords : x-ray laser * optical field ionization * spatial filtering * wavefront aberrations Subject RIV: BH - Optics, Masers, Lasers Impact factor: 3.059, year: 2009

  10. Aplanatic telescopes based on Schwarzschild optical configuration: from grazing incidence Wolter-like x-ray optics to Cherenkov two-mirror normal incidence telescopes

    Science.gov (United States)

    Sironi, Giorgia

    2017-09-01

    At the beginning of XX century Karl Schwarzschild defined a method to design large-field aplanatic telescopes based on the use of two aspheric mirrors. The approach was then refined by Couder (1926) who, in order to correct for the astigmatic aberration, introduced a curvature of the focal plane. By the way, the realization of normal-incidence telescopes implementing the Schwarzschild aplanatic configuration has been historically limited by the lack of technological solutions to manufacture and test aspheric mirrors. On the other hand, the Schwarzschild solution was recovered for the realization of coma-free X-ray grazing incidence optics. Wolter-like grazing incidence systems are indeed free of spherical aberration, but still suffer from coma and higher order aberrations degrading the imaging capability for off-axis sources. The application of the Schwarzschild's solution to X-ray optics allowed Wolter to define an optical system that exactly obeys the Abbe sine condition, eliminating coma completely. Therefore these systems are named Wolter-Schwarzschild telescopes and have been used to implement wide-field X-ray telescopes like the ROSAT WFC and the SOHO X-ray telescope. Starting from this approach, a new class of X-ray optical system was proposed by Burrows, Burg and Giacconi assuming polynomials numerically optimized to get a flat field of view response and applied by Conconi to the wide field x-ray telescope (WFXT) design. The Schwarzschild-Couder solution has been recently re-discovered for the application to normal-incidence Cherenkov telescopes, thanks to the suggestion by Vassiliev and collaborators. The Italian Institute for Astrophysics (INAF) realized the first Cherenkov telescope based on the polynomial variation of the Schwarzschild configuration (the so-called ASTRI telescope). Its optical qualification was successfully completed in 2016, demonstrating the suitability of the Schwarzschild-like configuration for the Cherenkov astronomy requirements

  11. Twin robotic x-ray system for 2D radiographic and 3D cone-beam CT imaging

    Science.gov (United States)

    Fieselmann, Andreas; Steinbrener, Jan; Jerebko, Anna K.; Voigt, Johannes M.; Scholz, Rosemarie; Ritschl, Ludwig; Mertelmeier, Thomas

    2016-03-01

    In this work, we provide an initial characterization of a novel twin robotic X-ray system. This system is equipped with two motor-driven telescopic arms carrying X-ray tube and flat-panel detector, respectively. 2D radiographs and fluoroscopic image sequences can be obtained from different viewing angles. Projection data for 3D cone-beam CT reconstruction can be acquired during simultaneous movement of the arms along dedicated scanning trajectories. We provide an initial evaluation of the 3D image quality based on phantom scans and clinical images. Furthermore, initial evaluation of patient dose is conducted. The results show that the system delivers high image quality for a range of medical applications. In particular, high spatial resolution enables adequate visualization of bone structures. This system allows 3D X-ray scanning of patients in standing and weight-bearing position. It could enable new 2D/3D imaging workflows in musculoskeletal imaging and improve diagnosis of musculoskeletal disorders.

  12. Concept development of X-ray mass thickness detection for irradiated items upon electron beam irradiation processing

    Science.gov (United States)

    Qin, Huaili; Yang, Guang; Kuang, Shan; Wang, Qiang; Liu, Jingjing; Zhang, Xiaomin; Li, Cancan; Han, Zhiwei; Li, Yuanjing

    2018-02-01

    The present project will adopt the principle and technology of X-ray imaging to quickly measure the mass thickness (wherein the mass thickness of the item =density of the item × thickness of the item) of the irradiated items and thus to determine whether the packaging size and inside location of the item will meet the requirements for treating thickness upon electron beam irradiation processing. The development of algorithm of X-ray mass thickness detector as well as the prediction of dose distribution have been completed. The development of the algorithm was based on the X-ray attenuation. 4 standard modules, Al sheet, Al ladders, PMMA sheet and PMMA ladders, were selected for the algorithm development. The algorithm was optimized until the error between tested mass thickness and standard mass thickness was less than 5%. Dose distribution of all energy (1-10 MeV) for each mass thickness was obtained using Monte-carlo method and used for the analysis of dose distribution, which provides the information of whether the item will be penetrated or not, as well as the Max. dose, Min. dose and DUR of the whole item.

  13. Towards tabletop production of intense quasimonochromatic X-ray beams using small 2-20 MeV accelerators

    International Nuclear Information System (INIS)

    Avakian, R.O.; Ispirian, K.A.

    2004-01-01

    Full text: The existing synchrotron radiation sources and the fourth generation x-ray sources, which are projected at SLAC, USA, and DESY, Germany, are very expensive. For this reason the search of the novel and cheaper sources using various types of radiation produced by 5-20 MeV electrons available at many hospitals, universities and firms in various countries is of great interest. In this article a review of the physics, history, new theoretical and experimental results and of some applications is given with a purpose to consider the possibilities of construction of small tabletop sources of quasimonochromatic X-ray photon beams necessary for scientific, industrial, medicine and other applications. Simple formulae for almost all types of radiation are given with the help of which one can estimate the expected useful yield and background. PACS: 41.60.-m; 43.35.Ty; 61.85+p;m 78.67.Pt; 78.70.-g. Key words: Bremsstrahlung/Cherenkov radiation/ Transition radiation / Parametric X-ray radiation / Channeling radiation/ Compton scattering

  14. Grazing incidence beam expander

    Energy Technology Data Exchange (ETDEWEB)

    Akkapeddi, P.R.; Glenn, P.; Fuschetto, A.; Appert, Q.; Viswanathan, V.K.

    1985-01-01

    A Grazing Incidence Beam Expander (GIBE) telescope is being designed and fabricated to be used as an equivalent end mirror in a long laser resonator cavity. The design requirements for this GIBE flow down from a generic Free Electron Laser (FEL) resonator. The nature of the FEL gain volume (a thin, pencil-like, on-axis region) dictates that the output beam be very small. Such a thin beam with the high power levels characteristic of FELs would have to travel perhaps hundreds of meters or more before expanding enough to allow reflection from cooled mirrors. A GIBE, on the other hand, would allow placing these optics closer to the gain region and thus reduces the cavity lengths substantially. Results are presented relating to optical and mechanical design, alignment sensitivity analysis, radius of curvature analysis, laser cavity stability analysis of a linear stable concentric laser cavity with a GIBE. Fabrication details of the GIBE are also given.

  15. Design and characterization of a multi-beam micro-CT scanner based on carbon nanotube field emission x-ray technology

    Science.gov (United States)

    Peng, Rui

    In this dissertation, I will present the results for my Ph.D. research for the past five years. My project mainly focuses on advanced imaging applications with a multi-beam x-ray source array based on carbon nanotube field emission technology. In the past few years, research in carbon nanotubes gradually changed from the raw material science to its application. Field emission x-ray application is one of the hottest research areas for carbon nanotube. Compared to traditional thermionic x-ray sources, the carbon nanotube field emission x-ray source has some natural advantages over traditional thermionic x-ray sources such as instantaneous x-ray generation, programmability and miniaturization. For the past few years, the research and development of carbon nanotube field emission x-ray has shifted from single x-ray beam applications to spatially distributed multi-beam x-ray sources. Previously in Zhou group, we have already built a gated micro-CT system with single beam micro-focus x-ray tube for higher spatial and temporal resolution as required in live animal imaging and a multi-beam tomosynthesis system targeting for faster and more stable breast imaging. Now my project mainly focused on the design, characterization and optimization of a multi-beam micro-CT imaging system. With the increase of gantry rotation speed approaching the mechanical limit, it is getting more and more difficult to further speed up the CT scanning. My new system promises a potential solution for the problem, and it serves as a great test platform for truly stationary micro-CT geometry. The potential capabilities it showed during the characterization and imaging measurements was promising. The dissertation is composed of five chapters. In Chapter 1, I will generally review the physics principles of x-ray generation and interaction with matter. Then the discovery of carbon nanotube and its great potential to serve as an excellent field emission electron source will be introduced in the second

  16. Test facility for astronomical x-ray optics

    DEFF Research Database (Denmark)

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

    1990-01-01

    Grazing incidence x-ray optics for x-ray astronomical applications are used outside the earth's atmosphere. These devices require a large collection aperture and the imaging of an x-ray source that is essentially placed at infinity. The ideal testing system for these optical elements has to appro......Grazing incidence x-ray optics for x-ray astronomical applications are used outside the earth's atmosphere. These devices require a large collection aperture and the imaging of an x-ray source that is essentially placed at infinity. The ideal testing system for these optical elements has...... to approximate that encountered under working conditions; however, the testing of these optical elements is notoriously difficult with conventional x-ray generators. Synchrotron radiation (SR) sources are sufficiently brilliant to produce a nearly perfect parallel beam over a large area while still retaining...... a flux considerably higher than that available from conventional x-ray generators. A facility designed for the testing of x-ray optics, particularly in connection with x-ray telescopes, is described. It is proposed that this facility will be accommodated at the Synchrotron Radiation Source...

  17. Glancing-incidence X-ray diffraction of Ag nanoparticles in gold lustre decoration of Italian Renaissance pottery

    International Nuclear Information System (INIS)

    Bontempi, E.; Colombi, P.; Depero, L.E.; Cartechini, L.; Presciutti, F.; Brunetti, B.G.; Sgamellotti, A.

    2006-01-01

    Lustre is known as one of the most significant decorative techniques of Medieval and Renaissance pottery in the Mediterranean basin, characterized by brilliant gold and red metallic reflections and iridescence effects. Previous studies by various techniques (SEM-EDS and TEM, UV-VIS, XRF, RBS and EXAFS) demonstrated that lustre consists of a heterogeneous metal-glass composite film, formed by Cu and Ag nanoparticles dispersed within the outer layer of a tin-opacified lead glaze. In the present work the investigation of an original gold lustre sample from Deruta has been carried out by means of glancing-incidence X-ray diffraction techniques (GIXRD). The study was aimed at providing information on structure and depth distribution of Ag nanoparticles. Exploiting the capability of controlling X-ray penetration in the glaze by changing the incidence angle, we used GIXRD measurements to estimate non-destructively thickness and depth of silver particles present in the first layers of the glaze. (orig.)

  18. Advanced laser-backlit grazing-incidence x-ray imaging systems for inertial confinement fusion research. II. Tolerance analysis

    International Nuclear Information System (INIS)

    Bennett, Guy R.; Folta, James A.

    2001-01-01

    Two example ultrahigh-spatial resolution laser-backlit grazing-incidence x-ray microscope designs for inertial confinement fusion (ICF) research have been described [Appl. Opt. 40, 4570 (2001)]. Here details of fabrication, assembly, and optical surface errors that are characteristic of present state-of-the-art superpolished multilayer-coated spherical mirrors are given. They indicate that good image qualities can be expected; in particular, <0.5-μm spatial resolution at very high x-ray energies (up to 25 keV) appears to be feasible. Existing ICF imaging diagnostics approach ∼2 μm spatial at low (<2 keV) energy. The improvement in resolution compared with that of other grazing-incidence devices is attributed to a fortuitous residual on-axis aberration dependence on short wavelengths; recent advances in mirror fabrication, including a new thin-film deposition technique to correct figure errors precisely in one dimension; and novel design. For even higher resolution, a means of creating precise aspherical mirrors of spheric-quality microroughness may be possible by use of the same deposition technique

  19. X-ray absorption anisotropy for polychromatic illumination-Crystal views from inside

    International Nuclear Information System (INIS)

    Korecki, P.; Tolkiehn, M.; Novikov, D.V.

    2009-01-01

    We review an atomic resolution imaging method based on the analysis of the fine structure in X-ray absorption anisotropy, which results from incident beam diffraction. For a polychromatic X-ray beam, due to the suppression of higher order diffraction fringes, X-ray absorption anisotropy patterns can be interpreted as distorted real-space projections of the atomic structure around absorbing atoms. A qualitative method for analysis of X-ray absorption anisotropy patterns is presented, based on modeling of X-ray patterns with ray-traced images calculated for clusters around absorbing atoms.

  20. Enacting laws concerning radiation safety management for students using X-rays and electron beams under 1 MeV

    International Nuclear Information System (INIS)

    Nishizawa, Kunihide; Shibata, Michihiro; Saze, Takuya

    2004-01-01

    Laws concerning radiation safety management were analyzed from the point of view of defining precisely what is meant by radiation and what is meant by the subject. There are no laws to protect students from radiation hazards when using X-rays and electron beams under 1 MeV for research and/or education. The Law concerning Technical Standards for Preventing Radiation Hazards gives the authorities the power to enact new rules and regulations that will protect the students. The Radiation Council must take charge for enactment of all laws regarding radiation safety management. (author)

  1. Towards brilliant, compact x-ray sources: a new x-ray photonic device

    Science.gov (United States)

    Scherer, Brian; Mandal, Sudeep; Salisbury, Joshua; Edic, Peter; Hopkins, Forrest; Lee, Susanne M.

    2017-05-01

    General Electric has designed an innovative x-ray photonic device that concentrates a polychromatic beam of diverging x-rays into a less divergent, parallel, or focused x-ray beam. The device consists of multiple, thin film multilayer stacks. X-rays incident on a given multilayer stack propagate within a high refractive index transmission layer while undergoing multiple total internal reflections from a novel, engineered multilayer containing materials of lower refractive index. Development of this device could lead to order-of-magnitude flux density increases, over a large broadband energy range from below 20 keV to above 300 keV. In this paper, we give an overview of the device and present GE's progress towards fabricating prototype devices.

  2. Fluorescence detection of white-beam X-ray absorption anisotropy: towards element-sensitive projections of local atomic structure

    Science.gov (United States)

    Korecki, P.; Tolkiehn, M.; Dąbrowski, K. M.; Novikov, D. V.

    2011-01-01

    Projections of the atomic structure around Nb atoms in a LiNbO3 single crystal were obtained from a white-beam X-ray absorption anisotropy (XAA) pattern detected using Nb K fluorescence. This kind of anisotropy results from the interference of X-rays inside a sample and, owing to the short coherence length of a white beam, is visible only at small angles around interatomic directions. Consequently, the main features of the recorded XAA corresponded to distorted real-space projections of dense-packed atomic planes and atomic rows. A quantitative analysis of XAA was carried out using a wavelet transform and allowed well resolved projections of Nb atoms to be obtained up to distances of 10 Å. The signal of nearest O atoms was detected indirectly by a comparison with model calculations. The measurement of white-beam XAA using characteristic radiation indicates the possibility of obtaining element-sensitive projections of the local atomic structure in more complex samples. PMID:21997909

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

    Science.gov (United States)

    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.

  4. Carbon ion beam is more effective to induce cell death in sphere-type A172 human glioblastoma cells compared with X-rays.

    Science.gov (United States)

    Takahashi, Momoko; Hirakawa, Hirokazu; Yajima, Hirohiko; Izumi-Nakajima, Nakako; Okayasu, Ryuichi; Fujimori, Akira

    2014-12-01

    To obtain human glioblastoma cells A172 expressing stem cell-related protein and comparison of radiosensitivity in these cells with X-rays and carbon beam. Human monolayer-type A172 glioblastoma cells were maintained in normal medium with 10% bovine serum. In order to obtain sphere-type A172 cells the medium was replaced with serum-free medium supplemented with growth factors. Both types of A172 cells were irradiated with either X-rays or carbon ion beams and their radiosensitivity was evaluated. Serum-free medium induced expression of stem cell-related proteins in A172 cells along with the neurosphere-like appearance. These sphere-type cells were found resistant to both X-rays and carbon ion beams. Phosphorylation of histone H2A family member X persisted for a longer period in the cells exposed to carbon ion beams than in those exposed to X-rays and it disappeared quicker in the sphere type than in the monolayer type. Relative radioresistance of the sphere type cells was smaller for carbon ion beams than for X-rays. We demonstrated that glioblastoma A172 cells with induced stem cell-related proteins turned resistant to irradiation. Accelerated heavy ion particles may have advantage over X-rays in overcoming the tumor resistance due to cell stemness.

  5. Studies for the development of a micro-focus monochromatic x-ray source with making use of a highly charged heavy ion beam

    International Nuclear Information System (INIS)

    Nakamura, Nobuyuki; Yoshiyasu, Nobuo; Nakayama, Ryo; Watanabe, Hirofumi

    2008-01-01

    We propose a new scheme for a micro-focus monochromatic X-ray source using a focused highly charged ion beam colliding with a solid surface. When highly charged ion approaches a surface, many electrons are captured into the ion and the so-called hollow atom is produced. The hollow atom will decay by emitting X-rays before and after hitting the surface. Such X-rays do not contain any contribution from bremsstrahlung, so that monochromatic X-rays can be obtained by using proper filters. For the first step of realizing the proposed scheme, an ion focusing system with a glass capillary has been developed. In order to study the monochromaticity of the emission, X-ray spectra from hollow atoms produced in the collisions between highly charged heavy ions and several surfaces have been observed. (author)

  6. Development of an x-ray beam line at the NSLS for studies in materials science using x-ray absorption spectroscopy: Annual progress report

    International Nuclear Information System (INIS)

    Sayers, D.E.

    1987-01-01

    The research programs reported span virtually the entire range of condensed matter studies involving the fields of solid state physics, chemistry, electrochemistry, materials science and biochemistry. Results are discussed for various groups. Topics reported include work on amorphous chalcogenide semiconductors, particularly photostructural changes, kinetics of structural changes and rapid quenching, bond strengths, force constants and phonons. Also reported are temperature dependent EXAFS studies of bonding in high temperature alloys, amorphous systems, disordered alloys and studies of resolve electronic structure, EXAFS and XANES studies of permanent magnet systems based on Nd 2 Fe 14 B, glancing angle EXAFS study of Nb/Al and Nb/Si interfacial systems, x-ray absorption of krypton-implanted solids and high dose implants into silicon, and x-ray absorption and EXAFS studies of superconducting oxide compounds of Cu and related magnetic systems. Work is also reported on XAFS measurements on the icosahedral phase

  7. X-ray generator

    International Nuclear Information System (INIS)

    Dawson, J.M.

    1976-01-01

    An apparatus and a method are described for producing coherent secondary x-rays that are controlled as to direction by illuminating a mixture of high z and low z gases with an intense burst of primary x-rays. The primary x-rays are produced with a laser activated plasma, and these x-rays strip off the electrons of the high z atoms in the lasing medium, while the low z atoms retain their electrons. The neutral atoms transfer electrons to highly excited states of the highly stripped high z ions giving an inverted population which produces the desired coherent x-rays. In one embodiment, a laser, light beam provides a laser spark that produces the intense burst of coherent x-rays that illuminates the mixture of high z and low z gases, whereby the high z atoms are stripped while the low z ones are not, giving the desired mixture of highly ionized and neutral atoms. Means for magnetically confining and stabilizing the plasma are disclosed for controlling the direction of the x-rays

  8. Generation of Medical X-ray and Terahertz Beams of Radiation Using Table-Top Accelerators

    OpenAIRE

    Baryshevsky, V.; Gurinovich, A.; Gurnevich, E.; Lobko, A.

    2013-01-01

    Theoretical and experimental studies of PXR and diffracted radiation of an oscillator in crystals combined with the development of VFEL generators with photonic crystals give a promising basis for creation of X-ray and THz sources using the same table-top accelerator. Multi-modal medical facility can be developed on the basis of one dedicated table-top electron accelerator of some tens of MeV energy. Such a system could find a lot of applications in medical practice and biomedical investigati...

  9. High energy white beam x-ray diffraction studies of residual strains in engineering components

    Science.gov (United States)

    Zhang, S. Y.; Vorster, W.; Jun, T. S.; Song, X.; Golshan, M.; Laundy, D.; Walsh, M. J.; Korsunsky, A. M.

    2008-09-01

    In order to predict the durability of engineering components and improve performance, it is mandatory to understand residual stresses. The last decade has witnessed a significant increase of residual stress evaluation using diffraction of penetrating radiation, such as neutrons or high energy X-rays. They provide a powerful non-destructive method for determining the level of residual stresses in engineering components through precise characterisation of interplanar crystal lattice spacing. The unique non-destructive nature of these measurement techniques is particularly beneficial in the context of engineering design, since it allows the evaluation of a variety of structural and deformational parameters inside real components without material removal, or at worst with minimal interference. However, while most real engineering components have complex shape and are often large in size, leading to measurement and interpretation difficulties, since experimental facilities usually have limited space for mounting the sample, limited sample travel range, limited loading capacity of the sample positioning system, etc. Consequently, samples often have to be sectioned, requiring appropriate corrections on measured data; or facilities must be improved. Our research group has contributed to the development of engineering applications of high-energy X-ray diffraction methods for residual stress evaluation, both at synchrotron sources and in the lab setting, including multiple detector setup, large engineering component manipulation and measurement at the UK Synchrotron Radiation Source (SRS Daresbury), and in our lab at Oxford. A nickel base superalloy combustion casing and a large MIG welded Al alloy plate were successfully studied.

  10. A simple X-ray source of two orthogonal beams for small samples imaging

    Science.gov (United States)

    Hrdý, J.

    2018-04-01

    A simple method for simultaneous imaging of small samples by two orthogonal beams is proposed. The method is based on one channel-cut crystal which is oriented such that the beam is diffracted on two crystallographic planes simultaneously. These planes are symmetrically inclined to the crystal surface. The beams are three times diffracted. After the first diffraction the beam is split. After the second diffraction the split beams become parallel. Finally, after the third diffraction the beams become convergent and may be used for imaging. The corresponding angular relations to obtain orthogonal beams are derived.

  11. An improved cone-beam filtered backprojection reconstruction algorithm based on x-ray angular correction and multiresolution analysis

    International Nuclear Information System (INIS)

    Sun, Y.; Hou, Y.; Yan, Y.

    2004-01-01

    With the extensive application of industrial computed tomography in the field of non-destructive testing, how to improve the quality of the reconstructed image is receiving more and more concern. It is well known that in the existing cone-beam filtered backprojection reconstruction algorithms the cone angle is controlled within a narrow range. The reason of this limitation is the incompleteness of projection data when the cone angle increases. Thus the size of the tested workpiece is limited. Considering the characteristic of X-ray cone angle, an improved cone-beam filtered back-projection reconstruction algorithm taking account of angular correction is proposed in this paper. The aim of our algorithm is to correct the cone-angle effect resulted from the incompleteness of projection data in the conventional algorithm. The basis of the correction is the angular relationship among X-ray source, tested workpiece and the detector. Thus the cone angle is not strictly limited and this algorithm may be used to detect larger workpiece. Further more, adaptive wavelet filter is used to make multiresolution analysis, which can modify the wavelet decomposition series adaptively according to the demand for resolution of local reconstructed area. Therefore the computation and the time of reconstruction can be reduced, and the quality of the reconstructed image can also be improved. (author)

  12. Measurement of backscatter factor for kilovoltage x-ray beam using ionization chamber and Gafchromic XR-QA2 film

    Science.gov (United States)

    Shukor, N. S. Ab; Asri, N. H. Mohd; Syed Jaafar, S. M. F.; Rosnan, M. S.; Aziz, S. A. Abdul

    2018-01-01

    Backscatter factor (BSF) is an important parameter in the determination of surface dose for kilovoltage X-ray beam. The purpose of this study was to measure the BSF for kilovoltage diagnostic X-ray beam, and compare the measured BSF between Gafchromic XR-QA2 film and shadow free (SFD) ionization chamber (IC). The parameters that may affect the BSF, such as tube voltage (kVp) and field size, were also studied. The results were in good agreement with the TRS 457, with deviation of less than 12 %. Based on the film study, the BSF obtained from the film measurement were found to be lower than that of the IC, with average difference of 26 %. It was also found that smaller field size resulted in lower effective energy, and the amount of photons which scattered back onto the surface were also smaller. This study demonstrated that the Gafchromic XR-QA2 film was not suitable for the application of small field size.

  13. A comparison of two photon planning algorithms for 8 MV and 25 MV X-ray beams in lung

    International Nuclear Information System (INIS)

    Kan, M.W.K.; Young, E.C.M.; Yu, P.K.N.

    1995-01-01

    The results of a comparison of two photon planning algorithms, the Clarkson Scatter Integration algorithm and the Equivalent Tissue-air Ratio algorithm are reported, using a simple lung phantom for 8 MV and 25 MV X-ray beams of field sizes 5 cm x 5 cm and 10 cm x 10 cm. Central axis depth-dose distributions were measured with a thimble chamber or a Markus parallel-plate chamber. Dose profile distributions were measured with TLD rods and films. Measured dose distributions were then compared to predicted dose distributions. Both algorithms overestimate the dose at mid-lung as they do not account for the effect of electronic disequilibrium. The Clarkson algorithm consistently shows less accurate results in comparison with the ETAR algorithm. There is additional error in the case of the Clarkson algorithm because of the assumption of a unit density medium in calculating scatter, which gives an overestimate in the effective scatter-air ratios in lung. For a 5 cm x 5 cm field, the error of dose prediction for 25 MV x-ray beam at mid-lung is 15.8 % and 12.8 % for Clarkson and ETAR algorithm respectively. At 8 MV the error is 9.3 % and 5.1 % respectively. In addition, both algorithms underestimate the penumbral width at mid-lung as they do not account for the penumbral flaring effect in low density medium. 25 refs., 2 tabs., 5 figs

  14. Determination of the energy dependence of the BC-408 plastic scintillation detector in medium energy x-ray beams

    Science.gov (United States)

    Yücel, H.; Çubukçu, Ş.; Uyar, E.; Engin, Y.

    2014-11-01

    The energy dependence of the response of BC-408 plastic scintillator (PS), an approximately water-equivalent material, has been investigated by employing standardized x-ray beams. IEC RQA and ISO N series x-ray beam qualities, in the range of 40-100 kVp, were calibrated using a PTW-type ionization chamber. The energy response of a thick BC-408 PS detector was measured using the multichannel pulse height analysis method. The response of BC-408 PS increased gradually with increasing energy in the energy range of 40-80 kVp and then showed a flat behavior at about 80 to 120 kVp. This might be due to the self-attenuation of scintillation light by the scintillator itself and may also be partly due to the ionization quenching, leading to a reduction in the intensity of the light output from the scintillator. The results indicated that the sensitivity drop in BC-408 PS material at lower photon energies may be overcome by adding some high-Z elements to its polyvinyltoluene (PVT) base. The material modification may compensate for the drop in the response at lower photon energies. Thus plastic scintillation dosimetry is potentially suitable for applications in diagnostic radiology.

  15. Stress measurements by multi-reflection grazing-incidence X-ray diffraction method (MGIXD) using different radiation wavelengths and different incident angles

    International Nuclear Information System (INIS)

    Marciszko, Marianna; Baczmański, Andrzej; Braham, Chedly; Wróbel, Mirosław; Wroński, Sebastian; Cios, Grzegorz

    2017-01-01

    The presented study introduces the development of the multi-reflection grazing-incidence X-ray diffraction method (MGIXD) for residual stress determination. The proposed new methodology is aimed at obtaining more reliable experimental data and increasing the depth of non-destructive stress determination below the sample surface. To verify proposed method measurements were performed on a classical X-ray diffractometer (Cu Kα radiation) and using synchrotron radiation (three different wavelengths: λ = 1.2527 Å, λ = 1.5419 Å and λ = 1.7512 Å). The Al2017 alloy subjected to three different surface treatments was investigated in this study. The obtained results showed that the proposed development of MGIXD method, in which not only different incident angles but also different wavelengths of X-ray are used, can be successfully applied for residual stress determination, especially when stress gradients are present in the sample.

  16. Fresnel zone plate telescopes for X-ray imaging II: numerical simulations with parallel and diverging beams

    Science.gov (United States)

    Palit, Sourav; Chakrabarti, Sandip Kumar; Debnath, Dipak; Rao, A. R.; Nandi, Anuj; Yadav, Vipin K.; Girish, V.

    2009-12-01

    We present the results of simulations of shadows cast by a zone plate telescope which may have one to four pairs of zone plates. From the shadows we reconstruct the images under various circumstances. We discuss physical basis of the resolution of the telescope and demonstrate this by our simulations. We allow the source to be at a finite distance (diverging beam) as well as at an infinite distance (parallel beam) and show that the resolution is worsened when the source is nearby. By reconstructing the zone plates in a way that both the zone plates subtend the same solid angles at the source, we obtain back high resolution even for sources at a finite distance. We present simulated results for the observation of the galactic center and show that the sources of varying intensities may be reconstructed with accuracy. Results of these simulations would be of immense use in interpreting the X-ray images from recently launched CORONAS-PHOTON satellite.

  17. Bremsstrahlung hard x-ray source driven by an electron beam from a self-modulated laser wakefield accelerator

    Science.gov (United States)

    Lemos, N.; Albert, F.; Shaw, J. L.; Papp, D.; Polanek, R.; King, P.; Milder, A. L.; Marsh, K. A.; Pak, A.; Pollock, B. B.; Hegelich, B. M.; Moody, J. D.; Park, J.; Tommasini, R.; Williams, G. J.; Chen, Hui; Joshi, C.

    2018-05-01

    An x-ray source generated by an electron beam produced using a Self-Modulated Laser Wakefield Accelerator (SM-LWFA) is explored for use in high energy density science facilities. By colliding the electron beam, with a maximum energy of 380 MeV, total charge of >10 nC and a divergence of 64 × 100 mrad, from a SM-LWFA driven by a 1 ps 120 J laser, into a high-Z foil, an x/gamma-ray source was generated. A broadband bremsstrahlung energy spectrum with temperatures ranging from 0.8 to 2 MeV was measured with an almost 2 orders of magnitude flux increase when compared with other schemes using LWFA. GEANT4 simulations were done to calculate the source size and divergence.

  18. Application of a tandem ionization chamber in a quality control program of X-ray beams, radiotherapy level

    International Nuclear Information System (INIS)

    Yoshizumi, Maira T.; Caldas, Linda V.E.

    2008-01-01

    A tandem ionization chamber, developed at the Instituto de Pesquisas Energeticas e Nucleares (IPEN), for X radiation beams, radiotherapy level, was applied into a quality control program of the Calibration Laboratory of IPEN. This ionization chamber is composed by two ionization chambers, with a volume of 0.6 cm 3 each one. Its inner plane-parallel electrodes and guard rings are made of different materials: one is made of aluminum and the other is made of graphite. Because of this difference in materials, the ionization chamber forms a tandem system. The relative response of the calibration factors of both sides of the chamber allows an easy verification of the X-ray beam qualities stability. The ionization chamber was submitted to some tests to verify the stability of its response: leakage current before and after exposure, repeatability and reproducibility. The performance of the ionization chamber was satisfactory. (author)

  19. Apoptosis and injuries of heavy ion beam and x-ray radiation on malignant melanoma cell.

    Science.gov (United States)

    Qin, Jin; Li, Sha; Zhang, Chao; Gao, Dong-Wei; Li, Qiang; Zhang, Hong; Jin, Xiao-Dong; Liu, Yang

    2017-05-01

    This study aims to investigate the influence of high linear energy transfer (LET) heavy ion ( 12 C 6+ ) and low LET X-ray radiation on apoptosis and related proteins of malignant melanoma on tumor-bearing mice under the same physical dosage. C57BL/6 J mice were burdened by tumors and randomized into three groups. These mice received heavy ion ( 12 C 6+ ) and X-ray radiation under the same physical dosage, respectively; their weight and tumor volumes were measured every three days post-radiation. After 30 days, these mice were sacrificed. Then, median survival time was calculated and tumors on mice were proliferated. In addition, immunohistochemistry was carried out for apoptosis-related proteins to reflect the expression level. After tumor-bearing mice were radiated to heavy ion, median survival time improved and tumor volume significantly decreased in conjunction with the upregulated expression of pro-apoptosis factors, Bax and cytochrome C, and the downregulated expression of apoptosis-profilin (Bcl-2, Survivin) and proliferation-related proteins (proliferating cell nuclear antigen). The results indicated that radiation can promote the apoptosis of malignant melanoma cells and inhibit their proliferation. This case was more suitable for heavy ion ( 12 C 6+ ). High LET heavy ion ( 12 C 6+ ) radiation could significantly improve the killing ability for malignant melanoma cells by inducing apoptosis in tumor cells and inhibiting their proliferation. These results demonstrated that heavy ion ( 12 C 6+ ) presented special advantages in terms of treating malignant melanoma. Impact statement Malignant melanoma is a malignant skin tumor derived from melanin cells, which has a high malignant degree and high fatality rate. In this study, proliferating cell nuclear antigen (PCNA) can induce the apoptosis of malignant melanoma cells and inhibit its proliferation, and its induction effect on apoptosis is significantly higher than low LET X-ray; hence, it is expected to

  20. Nondestructive quantitative synchrotron grazing incidence x-ray scattering analysis of cylindrical nanostructures in supported thin films

    International Nuclear Information System (INIS)

    Yoon, J.; Yang, S. Y.; Lee, B.; Joo, W.; Heo, K.; Kim, J. K.; Ree, M.; X-Ray Science Division; Pohang Univ. of Science and Technology

    2007-01-01

    Nondestructive nanostructural analysis is indispensable in the development of nanomaterials and nanofabrication processes for use in nanotechnology applications. This paper demonstrates a quantitative, nondestructive analysis of nanostructured thin films supported on substrates and their templated nanopores by using grazing incidence X-ray scattering and data analysis with a derived scattering theory. The analysis disclosed that vertically oriented nanodomain cylinders had formed in 20-100 nm thick films supported on substrates, which consisted of a mixture of poly(styrene-b-methyl methacrylate) (PS-b-PMMA) and PMMA homopolymer, and that the PMMA nanodomain cylinders were selectively etched out by ultraviolet light exposure and a subsequent rinse with acetic acid, resulting in a well ordered nanostructure consisting of hexagonally packed cylindrical nanopores

  1. Computer-Controlled Cylindrical Polishing Process for Development of Grazing Incidence Optics for Hard X-Ray Region

    Science.gov (United States)

    Khan, Gufran Sayeed; Gubarev, Mikhail; Speegle, Chet; Ramsey, Brian

    2010-01-01

    The presentation includes grazing incidence X-ray optics, motivation and challenges, mid spatial frequency generation in cylindrical polishing, design considerations for polishing lap, simulation studies and experimental results, future scope, and summary. Topics include current status of replication optics technology, cylindrical polishing process using large size polishing lap, non-conformance of polishin lap to the optics, development of software and polishing machine, deterministic prediction of polishing, polishing experiment under optimum conditions, and polishing experiment based on known error profile. Future plans include determination of non-uniformity in the polishing lap compliance, development of a polishing sequence based on a known error profile of the specimen, software for generating a mandrel polishing sequence, design an development of a flexible polishing lap, and computer controlled localized polishing process.

  2. Depth profile characterization of electrodeposited multi-thin-film structures by low angle of incidence X-ray diffractometry

    International Nuclear Information System (INIS)

    Nauer, M.; Ernst, K.; Kautek, W.; Neumann-Spallart, M.

    2005-01-01

    Typical structures of heterojunction photovoltaic cells were prepared by sequential electrodeposition of II-VI semiconductor thin films on a transparent conductor, SnO 2 on glass. The structures comprised a wide bandgap window, ZnSe or ZnTe, a medium bandgap light absorber, CdTe, and an ohmic back contact. It is demonstrated that low incidence angle X-ray diffraction (LIXD) can be successfully used as a process monitoring tool, featuring non-destructive depth profiling and phase characterization of such thin film structures. LIXD results are compared to Secondary Ion Mass Spectroscopy (SIMS) and Scanning Electron Microscopy (SEM) data. Both, SIMS and SEM, corroborate the LIXD results as to layer sequence and presence/absence of intermixing

  3. Structure of a monolayer of molecular rotors on aqueous subphase from grazing-incidence X-ray diffraction.

    Science.gov (United States)

    Kaleta, Jiří; Wen, Jin; Magnera, Thomas F; Dron, Paul I; Zhu, Chenhui; Michl, Josef

    2018-03-23

    In situ grazing-incidence X-ray scattering shows that a monolayer of artificial rod-shaped dipolar molecular rotors produced on the surface of an aqueous subphase in a Langmuir trough has a structure conducive to a 2D ferroelectric phase. The axes of the rotors stand an average of 0.83 nm apart in a triangular grid, perpendicular to the surface within experimental error. They carry 2,3-dichlorophenylene rotators near rod centers, between two decks of interlocked triptycenes installed axially on the rotor axle. The analysis is based first on simultaneous fitting of observed Bragg rods and second on fitting the reflectivity curve with only three adjustable parameters and the calculated rotor electron density, which also revealed the presence of about seven molecules of water near each rotator. Dependent on preparation conditions, a minor and variable amount of a different crystal phase may also be present in the monolayer.

  4. Feasibility and applications of cone beam x-ray imaging for containerized wastes

    Energy Technology Data Exchange (ETDEWEB)

    Roney, T.; Galbraith, S.; White, T. [Idaho National Engineering Lab., Idaho Falls, ID (United States); Clack, R.; O`Reilly, M. [Utah Univ., Salt Lake City, UT (United States); Defrise, M. [Free Univ., Brussels (Belgium); Noo, F. [Association des Ingenieurs Electriciens, Liege (Belgium). L`Inst. Electrotechnique Montefiore

    1995-12-01

    Large area scintillation screens coupled to video and scientific-grade CCD cameras allow high speed digital data acquisition for both single 2-D x-ray projections and tomographic data sets comprised of multiple 2-D projections. While the data cquisition may proceed more rapidly than data acquisition using a linear detector array, there are geometric distortions associated with the projection cone angle long processing times for 3-D tomographic data. This paper reviews issues associated with processing and interpretation of the data and approaches to resolving some of the problems for containerized waste inspection. Results obtained with the Idaho National Engineering Laboratory`s Digital Radiography and Computed Tomography scanner are presented.

  5. X-ray topography of natural diamonds on the VEPP-3 SR beam

    International Nuclear Information System (INIS)

    Kuper, K.E.; Zedgenizov, D.A.; Ragozin, A.L.; Shatsky, V.S.

    2009-01-01

    X-ray topography (XRT) images were obtained using a double-crystal topographic method, with a magnification system in the Laue case. The experiment was performed at the beamline station 'Microscopy and tomography' of the VEPP-3 synchrotron radiation source. Two asymmetrically cut crystals in the Kirkpatrick-Baez scheme were used to increase the spatial resolution. The usage of an asymmetrically cut crystal with a magnification factor of 20 allows us to improve spatial resolution in registered images. A series of slabs of natural diamonds from kimberlite pipes and placers of the Siberian platform was examined. This study confirmed the high efficiency of the XRT method to recover information on the internal structure of natural diamonds. Together with other mineralogical data, the features of internal structure determined by this way are important to deduce the origin and history of growth of natural diamonds.

  6. Applications of low-density foams for x-ray source studies and laser beam smoothing

    Czech Academy of Sciences Publication Activity Database

    Limpouch, J.; Renner, Oldřich; Borisenko, N.G.; Klír, D.; Kmetík, Viliam; Krouský, Eduard; Liska, R.; Mašek, Karel; Nazarov, W.; Ullschmied, Jiří

    2008-01-01

    Roč. 112, 042056 (2008), s. 1-4 ISSN 1742-6588. [The Fifth International Conference on Inertial Fusion Sciences and Applications (IFSA2007). Kobe, 09.09.2007-14.09.2007] R&D Projects: GA MŠk(CZ) LC528; GA ČR GA202/06/0801 Institutional research plan: CEZ:AV0Z10100523; CEZ:AV0Z20430508 Keywords : plasma * x-ray generation * energy transport in plasma * bremsstrahlung * laser-light transmission through inhomogeneous plasma * laser-propagation in undercritical plasma Subject RIV: BL - Plasma and Gas Discharge Physics http://www.iop.org/EJ/article/1742-6596/112/4/042056/jpconf8_112_042056.pdf

  7. MeV single-ion beam irradiation of mammalian cells using the Surrey vertical nanobeam, compared with broad proton beam and X-ray irradiations

    Energy Technology Data Exchange (ETDEWEB)

    Prakrajang, K. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Faculty of Science, Maejo University, Chiang Mai 50290 (Thailand); Jeynes, J.C.G.; Merchant, M.J.; Kirkby, K.; Kirkby, N. [Surrey Ion Beam Center, Faculty of Engineering and Physical Science, University of Surrey, Guildford Surrey, GU2 7XH (United Kingdom); Thopan, P. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Yu, L.D., E-mail: yuld@fnrf.science.cmu.ac.th [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thailand Center of Excellence in Physics, Commission on Higher Education, 328 Si Ayutthaya Road, Bangkok 10400 (Thailand)

    2013-07-15

    Highlights: •Recently completed nanobeam at the Surrey Ion Beam Centre was used. •3.8-MeV single and broad proton beams irradiated Chinese hamster cells. •Cell survival curves were measured and compared with 300-kV X-ray irradiation. •Single ion irradiation had a lower survival part at ultra-low dose. •It implies hypersensitivity, bystander effect and cell cycle phase of cell death. -- Abstract: As a part of a systematic study on mechanisms involved in physical cancer therapies, this work investigated response of mammalian cells to ultra-low-dose ion beam irradiation. The ion beam irradiation was performed using the recently completed nanobeam facility at the Surrey Ion Beam Centre. A scanning focused vertical ion nano-beam was applied to irradiate Chinese hamster V79 cells. The V79 cells were irradiated in two different beam modes, namely, focused single ion beam and defocused scanning broad ion beam of 3.8-MeV protons. The single ion beam was capable of irradiating a single cell with a precisely controlled number of the ions to extremely low doses. After irradiation and cell incubation, the number of surviving colonies as a function of the number of the irradiating ions was measured for the cell survival fraction curve. A lower survival for the single ion beam irradiation than that of the broad beam case implied the hypersensitivity and bystander effect. The ion-beam-induced cell survival curves were compared with that from 300-kV X-ray irradiation. Theoretical studies indicated that the cell death in single ion irradiation mainly occurred in the cell cycle phases of cell division and intervals between the cell division and the DNA replication. The success in the experiment demonstrated the Surrey vertical nanobeam successfully completed.

  8. Study of electron beams within ISTTOK tokamak by means of a multi-channel Cherenkov detector; their correlation with hard X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Jakubowski, L., E-mail: Lech.Jakubowski@ipj.gov.p [Andrzej Soltan Institute for Nuclear Studies, 05-400 Otwock-Swierk (Poland); Malinowski, K.; Sadowski, M.J.; Zebrowski, J. [Andrzej Soltan Institute for Nuclear Studies, 05-400 Otwock-Swierk (Poland); Plyusnin, V.V. [Association Euratom/IST, Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Rabinski, M. [Andrzej Soltan Institute for Nuclear Studies, 05-400 Otwock-Swierk (Poland); Fernandes, H.; Silva, C.; Duarte, P. [Association Euratom/IST, Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Jakubowski, M.J. [Andrzej Soltan Institute for Nuclear Studies, 05-400 Otwock-Swierk (Poland)

    2010-11-11

    The paper describes experimental studies of electron beams emitted from a plasma torus within the ISTTOK tokamak, which were performed by means of a new four-channel detector of the Cherenkov type. A range of electron energy was estimated. There were also measured hard X-rays, and their correlation with the fast run-away electron beams was investigated experimentally.

  9. Grazing incidence reflectivity and total electron yield effects in soft x-ray absorption spectroscopy

    NARCIS (Netherlands)

    Alders, D; Hibma, T; Sawatzky, G.A; Cheung, K.C.; van Dorssen, G.E.; Roper, M.D.; Padmore, H.A.; van der Laan, G.; Vogel, J; Sacchi, M.

    1997-01-01

    We report on a study of grazing incidence absorption and reflection spectra of NiO in the region of the Ni 2p edge. The aim is to evaluate the distortion of the near edge spectrum by the critical angle behavior of individual components within the spectrum. This can be used to improve the separation

  10. Generation of femtosecond soft x-ray pulse by interaction between laser and electron beam in an electron storage ring

    CERN Document Server

    Inoue, T; Amano, S; Mochizuki, T; Yatsuzaka, M

    2002-01-01

    A femtosecond synchrotron radiation pulse train can be extracted from an electron storage ring by interaction between an ultrashort laser pulse and an electron beam in an undulator. Generation system of a femtosecond soft x-ray pulse by the slicing technique was studied with numerical calculations for its performance, as applicable for the NewSUBARU synchrotron radiation facility at LASTI. The femtosecond electron pulse, that is energy-modulated with a Ti:sapphire laser at a pulse energy of 100 mu J, a pulse width of 150 fs, and repetition frequency of 20 kHz, can be sufficiently separated in a bending magnet. A femtosecond soft x-ray pulse (the critical photon energy of 0.69 keV and a pulse width of 250 fs) is obtained with a collimator (diameter of 800 mu m phi), and it has an average brightness 3 x 10 sup 6 photons/s/mm sup 2 /mrad sup 2 /0.1 %BW and an average photon flux 10 sup 5 photons/s/0.1 %BW. (author)

  11. X-ray absorption microtomography (microCT) and small beam diffraction mapping of sea urchin teeth.

    Science.gov (United States)

    Stock, S R; Barss, J; Dahl, T; Veis, A; Almer, J D

    2002-07-01

    Two noninvasive X-ray techniques, laboratory X-ray absorption microtomography (microCT) and X-ray diffraction mapping, were used to study teeth of the sea urchin Lytechinus variegatus. MicroCT revealed low attenuation regions at near the tooth's stone part and along the carinar process-central prism boundary; this latter observation appears to be novel. The expected variation of Mg fraction x in the mineral phase (calcite, Ca(1-x)Mg(x)CO(3)) cannot account for all of the linear attenuation coefficient decrease in the two zones: this suggested that soft tissue is localized there. Transmission diffraction mapping (synchrotron X-radiation, 80.8 keV, 0.1 x 0.1mm(2) beam area, 0.1mm translation grid, image plate area detector) simultaneously probed variations in 3-D and showed that the crystal elements of the "T"-shaped tooth were very highly aligned. Diffraction patterns from the keel (adaxial web) and from the abaxial flange (containing primary plates and the stone part) differed markedly. The flange contained two populations of identically oriented crystal elements with lattice parameters corresponding to x=0.13 and x=0.32. The keel produced one set of diffraction spots corresponding to the lower x. The compositions were more or less equivalent to those determined by others for camarodont teeth, and the high Mg phase is expected to be disks of secondary mineral epitaxially related to the underlying primary mineral element. Lattice parameter gradients were not noted in the keel or flange. Taken together, the microCT and diffraction results indicated that there was a band of relatively high protein content, of up to approximately 0.25 volume fraction, in the central part of the flange and paralleling its adaxial and abaxial faces. X-ray microCT and microdiffraction data used in conjunction with protein distribution data will be crucial for understanding the properties of various biocomposites and their mechanical functions.

  12. Electron beam halo monitor for a compact x-ray free-electron laser

    Directory of Open Access Journals (Sweden)

    Hideki Aoyagi

    2013-03-01

    Full Text Available An electron beam halo monitor using diamond-based detectors, which are operated in the ionization mode, has been developed for the SPring-8 Angstrom compact free-electron laser (SACLA to protect its undulator magnets from radiation damage. Diamond-based detectors are inserted in a beam duct to measure the intensity of the beam halo directly. To suppress the degradation of the electron beam due to the installation of the beam halo monitor, rf fingers with aluminum windows are newly employed. We evaluated the effect of radiation from the Al windows on the output signal both experimentally and by simulation. The operational results of the beam halo monitor employed in SACLA are presented.

  13. Laser Plasma Sources for High Brightness Beams from THz to X-rays

    CERN Document Server

    Leemans, W; Fubiani, G; Geddes, C G R; Michel, P; Nagler, B; Nakamura, K; Schroeder, C B; Shadwick, B; Toth, C; Van Tilborg, J

    2005-01-01

    Laser driven accelerators are capable of producing energetic electron beams using ultra-high gradients on the order of 10-100 GV/m. Prior to 2004, experiments had demonstrated high energy acceleration but with 100 % energy spread. Recent experiments have shown that 100 MeV class intense electron beams with narrow energy spread [1-3] can be generated in mm-scale structures. At the multi-beam L’OASIS facility at LBNL we have produced beams with narrow energy spread using a channel guided laser accelerator [1]. As opposed to single beam experiments, two additional laser beams are used to first produce a plasma channel which then guides an intense drive laser beam over greater distances than in single beam experiments. By properly controlling the channel, 100 MeV-class beams were produced with few percent energy spread, containing 0.3 nC of charge and with a normalized emittance around 1-2 π mm-mrad. Characterization of the bunch length and shape is underway using an electro-optic technique op...

  14. Construction of an ionization chamber for buildup measurements in megavoltage X-ray beams

    International Nuclear Information System (INIS)

    Rawlinson, J.A.; Pereira Junior, P.P.

    1979-01-01

    The design and construction of a simple homemade ion chamber for brildup measurements in megavoltage beams is described. Tests indicate that the performance of the chamber is superior in some respects to a commercially available chamber. Results obtained using the chamber in a 6 MV beam are presented. (Author) [pt

  15. Pin-photodiode array for the measurement of fan-beam energy and air kerma distributions of X-ray CT scanners.

    Science.gov (United States)

    Haba, Tomonobu; Koyama, Shuji; Aoyama, Takahiko; Kinomura, Yutaka; Ida, Yoshihiro; Kobayashi, Masanao; Kameyama, Hiroshi; Tsutsumi, Yoshinori

    2016-07-01

    Patient dose estimation in X-ray computed tomography (CT) is generally performed by Monte Carlo simulation of photon interactions within anthropomorphic or cylindrical phantoms. An accurate Monte Carlo simulation requires an understanding of the effects of the bow-tie filter equipped in a CT scanner, i.e. the change of X-ray energy and air kerma along the fan-beam arc of the CT scanner. To measure the effective energy and air kerma distributions, we devised a pin-photodiode array utilizing eight channels of X-ray sensors arranged at regular intervals along the fan-beam arc of the CT scanner. Each X-ray sensor consisted of two plate type of pin silicon photodiodes in tandem - front and rear photodiodes - and of a lead collimator, which only allowed X-rays to impinge vertically to the silicon surface of the photodiodes. The effective energy of the X-rays was calculated from the ratio of the output voltages of the photodiodes and the dose was calculated from the output voltage of the front photodiode using the energy and dose calibration curves respectively. The pin-photodiode array allowed the calculation of X-ray effective energies and relative doses, at eight points simultaneously along the fan-beam arc of a CT scanner during a single rotation of the scanner. The fan-beam energy and air kerma distributions of CT scanners can be effectively measured using this pin-photodiode array. Copyright © 2016 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  16. Soft x-ray lasers

    International Nuclear Information System (INIS)

    Matthews, D.L.; Rosen, M.D.

    1988-01-01

    One of the elusive dreams of laser physicists has been the development of an x-ray laser. After 25 years of waiting, the x-ray laser has at last entered the scientific scene, although those now in operation are still laboratory prototypes. They produce soft x rays down to about five nanometers. X-ray lasers retain the usual characteristics of their optical counterparts: a very tight beam, spatial and temporal coherence, and extreme brightness. Present x-ray lasers are nearly 100 times brighter that the next most powerful x-ray source in the world: the electron synchrotron. Although Lawrence Livermore National Laboratory (LLNL) is widely known for its hard-x-ray laser program which has potential applications in the Strategic Defense Initiative, the soft x-ray lasers have no direct military applications. These lasers, and the scientific tools that result from their development, may one day have a place in the design and diagnosis of both laser fusion and hard x-ray lasers. The soft x-ray lasers now in operation at the LLNL have shown great promise but are still in the primitive state. Once x-ray lasers become reliable, efficient, and economical, they will have several important applications. Chief among them might be the creation of holograms of microscopic biological structures too small to be investigated with visible light. 5 figs

  17. A new method for x-ray scatter correction: first assessment on a cone-beam CT experimental setup

    Energy Technology Data Exchange (ETDEWEB)

    Rinkel, J [CEA-LETI MINATEC, Division of Micro Technologies for Biology and Healthcare, 38054 Grenoble Cedex 09 (France); Gerfault, L [CEA-LETI MINATEC, Division of Micro Technologies for Biology and Healthcare, 38054 Grenoble Cedex 09 (France); Esteve, F [INSERM U647-RSRM, ESRF, BP200, 38043 Grenoble Cedex 09 (France); Dinten, J-M [CEA-LETI MINATEC, Division of Micro Technologies for Biology and Healthcare, 38054 Grenoble Cedex 09 (France)

    2007-08-07

    Cone-beam computed tomography (CBCT) enables three-dimensional imaging with isotropic resolution and a shorter acquisition time compared to a helical CT scanner. Because a larger object volume is exposed for each projection, scatter levels are much higher than in collimated fan-beam systems, resulting in cupping artifacts, streaks and quantification inaccuracies. In this paper, a general method to correct for scatter in CBCT, without supplementary on-line acquisition, is presented. This method is based on scatter calibration through off-line acquisition combined with on-line analytical transformation based on physical equations, to adapt calibration to the object observed. The method was tested on a PMMA phantom and on an anthropomorphic thorax phantom. The results were validated by comparison to simulation for the PMMA phantom and by comparison to scans obtained on a commercial multi-slice CT scanner for the thorax phantom. Finally, the improvements achieved with the new method were compared to those obtained using a standard beam-stop method. The new method provided results that closely agreed with the simulation and with the conventional CT scanner, eliminating cupping artifacts and significantly improving quantification. Compared to the beam-stop method, lower x-ray doses and shorter acquisition times were needed, both divided by a factor of 9 for the same scatter estimation accuracy.

  18. Thermal management and prototype testing of Compton scattering X-ray beam position monitor for the Advanced Photon Source Upgrade

    Science.gov (United States)

    Lee, S. H.; Yang, B. X.; Collins, J. T.; Ramanathan, M.

    2017-02-01

    Accurate and stable x-ray beam position monitors (XBPMs) are key elements in obtaining the desired user beam stability in the Advanced Photon Source Upgrade. In the next-generation XBPMs for the canted-undulator front ends, where two undulator beams are separated by 1.0 mrad, the lower beam power (changes through the interface via thermal simulations, the thermal contact resistance (TCR) of TIMs at an interface between two solid materials under even contact pressure must be known. This paper addresses the TCR measurements of several TIMs, including gold, silver, pyrolytic graphite sheet, and 3D graphene foam. In addition, a prototype of a Compton-scattering XBPM with diamond blades was installed at APS Beamline 24-ID-A in May 2015 and has been tested. This paper presents the design of the Compton-scattering XBPM, and compares thermal simulation results obtained for the diamond blade of this XBPM by the finite element method with in situ empirical measurements obtained by using reliable infrared technology.

  19. Research and Design of a Sample Heater for Beam Line 6-2c Transmission X-ray Microscope

    Energy Technology Data Exchange (ETDEWEB)

    Policht, Veronica; /Loyola U., Chicago /SLAC

    2012-08-27

    There exists a need for environmental control of samples to be imaged by the Transmission X-Ray Microscope (TXM) at the SSRLs Beam Line 6-2c. In order to observe heat-driven chemical or morphological changes that normally occur in situ, microscopes require an additional component that effectively heats a given sample without heating any of the microscope elements. The confinement of the heat and other concerns about the heaters integrity limit which type of heater is appropriate for the TXM. The bulk of this research project entails researching different heating methods used previously in microscopes, but also in other industrial applications, with the goal of determining the best-fitting method, and finally in designing a preliminary sample heater.

  20. Development of an image intensifier-TV digital imaging system with a multiple-slit scanning x-ray beam

    International Nuclear Information System (INIS)

    Kume, Y.; Doi, K.

    1986-01-01

    The authors are developing a new digital x-ray imaging system employing a multiple-slit assembly (MSA) and an image intensifier (II)-TV digital system. The final image consisting of primary radiation is digitally reconstructed from multiple slit images obtained with the MSA. This system can significantly reduce the scattered radiation from an object and the veiling glare from II-TV system. The quality of the reconstructed image is related to many parameters, such as slit width, the number of image frames, and the image reconstruction algorithm. They present the effect of these various parameters on basic imaging properties and the practicability of the method in comparison with conventional wide beam imaging

  1. Damage thresholds for blaze diffraction gratings and grazing incidence optics at an X-ray free-electron laser.

    Science.gov (United States)

    Krzywinski, Jacek; Conley, Raymond; Moeller, Stefan; Gwalt, Grzegorz; Siewert, Frank; Waberski, Christoph; Zeschke, Thomas; Cocco, Daniele

    2018-01-01

    The Linac Coherent Light Source is upgrading its machine to high repetition rate and to extended ranges. Novel coatings, with limited surface oxidation, which are able to work at the carbon edge, are required. In addition, high-resolution soft X-ray monochromators become necessary. One of the big challenges is to design the mirror geometry and the grating profile to have high reflectivity (or efficiency) and at the same time survive the high peak energy of the free-electron laser pulses. For these reasons the experimental damage threshold, at 900 eV, of two platinum-coated gratings with different blazed angles has been investigated. The gratings were tested at 1° grazing incidence. To validate a model for which the damage threshold on the blaze grating can be estimated by calculating the damage threshold of a mirror with an angle of incidence identical to the angle of incidence on the grating plus the blaze angle, tests on Pt-coated substrates have also been performed. The results confirmed the prediction. Uncoated silicon, platinum and SiB 3 (both deposited on a silicon substrate) were also investigated. In general, the measured damage threshold at grazing incidence is higher than that calculated under the assumption that there is no energy transport from the volume where the photons are absorbed. However, it was found that, for the case of the SiB 3 coating, the grazing incidence condition did not increase the damage threshold, indicating that the energy transport away from the extinction volume is negligible.

  2. Nonintercepting Electron Beam Diagnostics Based on Optical Diffraction Radiation for X-Ray FELs

    CERN Document Server

    Lumpkin, Alex H; Sereno, N S; Yang, B X; Yao, C

    2005-01-01

    The challenge of providing nonintercepting beam diagnostics that address transverse parameters such as beam size and divergence in a linear transport line has been met. We have successfully used near-field imaging of optical diffraction radiation (ODR) from a 7-GeV electron beam passing near a single edge of a conducting screen to obtain beam size for the first time [1]. In this case appreciable visible wavelength ODR is emitted for impact parameters of 1 to 2 mm, values that are close to gamma times the reduced observation wavelength. We have now upgraded our imaging system to include an intensified camera; selectable bandpass filters, neutral density filters, and polarizers; a steering mirror; and an optical lens setup that provides either near-field or far-field imaging. The ODR has been obtained in both the single-edge mode and aperture mode with a single pulse of 3.3 nC. Beam-size resolution in the 20-50 micron regime is projected while beam position resolution to 10 microns with a smaller beam and highe...

  3. Analysis of InGaN nanodots grown by droplet heteroepitaxy using grazing incidence small-angle X-ray scattering and electron microscopy

    Science.gov (United States)

    Woodward, J. M.; Nikiforov, A. Yu.; Ludwig, K. F.; Moustakas, T. D.

    2017-08-01

    We present a detailed structural investigation of self-assembled indium gallium nitride nanodots grown on c-plane aluminum nitride templates by the droplet heteroepitaxy technique in a plasma-assisted molecular beam epitaxy reactor. Various growth parameters, including the total coverage of the metal species, relative and total metal effusion fluxes, and nitridation temperature were investigated. Analyses of in situ reflection high-energy electron diffraction patterns and comparison with simulations showed that the resulting crystal structure was a mixture of wurtzite and twinned zinc blende phases, with the zinc blende phase increasingly dominant for lower metal coverages and lower nitridation temperatures, and the wurtzite phase increasingly dominant for higher nitridation temperature. Studies by field emission scanning electron microscopy and atomic force microscopy revealed that the nanodots exhibit trimodal size distributions, with the dot morphologies of the intermediate size mode often resembling aggregations of distinct clusters. Nanodots grown at higher nitridation temperatures had larger inter-dot spacings, with hexagonal in-plane ordering observable at a sufficiently high temperature. Using grazing incidence small angle X-ray scattering, we determined the nanodots to be approximately truncated cone shaped, and extracted the mean radius, height, and inter-dot distance for each distribution. Microstructural investigations of the nanodots by cross-sectional transmission electron microscopy indicated that the majority of the dots were formed in dislocation-free regions, and confirmed that the intermediate size dots were approximately truncated cone shaped and consisted of both zinc blende and wurtzite regions. Mapping of the elemental distributions by energy dispersive X-ray spectroscopy in scanning transmission electron microscopy mode indicated highly nonuniform indium distributions within both small and intermediate size dots which are potentially

  4. Automatic collimator of a scanner X-ray beam and implementation process. Dispositif automatique de collimation d'un faisceau de rayons X d'un scanner et procede de mise en oeuvre

    Energy Technology Data Exchange (ETDEWEB)

    Feldman, A.

    1994-07-13

    The patent involves the X-ray scanner. The X-ray source includes a two plate collimator. These plates are movable owing to a moving means in order to increase or decrease the X-ray beam aperture and so as to intercept the X-rays which should not be reduced by the patient body. The invention applies especially to radiography used scanners. 5 refs., 10 figs.

  5. Measurement of depth dose factors for various 60-Co and X-ray beams using ion chambers and thermoluminescent dosemeters

    International Nuclear Information System (INIS)

    Milu, C.

    1983-06-01

    As the depth dose factors may vary with the type of 60 Co unit (or X-ray generator) several determinations in this direction were done. The depth doses (mGy/s) for 60 Co beam (SSD=80cm) for the depths 5,10,15 and 20 cm were 11.92, 8.25, 5.75 and resp. 4.10 for field size 10x10 cm and 12.70, 9.42, 6.63 and resp. 4.93 for field size 20x20 cm. In X-ray beam, the depth doses (mGy/s) for FSD=50 cm, open-end and field size 10 cm diam. were: 1.78, 0.66, 0.23 and 0.09 for 100 kV (0.143 mm HVL, in air) and depths 5, 10, 15 and resp. 20 cm; 2.61, 1.12, 0.46 and 0.19 for 135 kV and 4.13, 1.88, 0.88 and 0.40 for 180 kV. The quality of the radiation at different depths in the water phantom was determined using a tandem TLD within Cu sleeve and TLD without Cu sleeve. The values obtained ranged from 0.018 mm Cu for 100 kV to 0.170 for 180 kV at depth 5 cm. All determinations were done using an IAEA perspex water tank and Harshaw extruded LiF as detectors. An intercomparison using LiF powder capsules prepared and sent by the IAEA Dosimetry Laboratory was performed too, in order to check the consistency of thermoluminescent dosimetry systems

  6. Sensor device for X-ray beam to evaluate the radiation focal spot

    International Nuclear Information System (INIS)

    Santos, Lara H.E. dos; Schiabel, Homero; Silva, Aderbal A.B. da; Marques, Paulo M.A.; Campos, Marcelo; Slaets, Annie F.F.

    1996-01-01

    A new electronic device to determine the position of the central ray of the radiation beam is proposed. The device aims to provide a perfect alignment of test objects used for evaluating focal spots with this reference axis

  7. Slit x-ray beam primary dose profiles determined by analytical transport of Compton recoil electrons

    NARCIS (Netherlands)

    van't Veld, AA; van Luijk, P; Praamstra, F; van der Hulst, PC

    Accurate measurement of radiation beam penumbras is essential for conformal radiotherapy. For this purpose a detailed knowledge of the dosimeter's spatial response is required. However, experimental determination of detector spatial response is cumbersome and restricted to the specific detector type

  8. P3HT/PCBM polymer thin films studied by synchrotron-based grazing incidence X-ray diffraction

    International Nuclear Information System (INIS)

    Yang Yingguo; Zhengguan Haojie; Ji Gengwu; Feng Shanglei; Li Xiaolong; Gao Xingyu

    2014-01-01

    Background: The microstructures of P3HT (poly(3-hexyl-thiophene)) in P3HT/PCBM ([6, 6]-phenyl C61-butyric acid methyl ester) thin films play a key role in governing the performance of organic solar cells (OSCs) based on these films. Purpose: We aim to study the self-organization of P3HT in the P3HT/PCBM thin films annealed at different temperatures. Methods: Using different incidence angles, information about the microstructures of P3HT at different depths in these films was obtained by synchrotron based grazing incidence X-ray diffraction (GIXRD). Results: It is shown that the crystalline structure of P3HT has been substantially improved by thermal annealing. One dimensional GIXRD clearly indicates that P3HT edge-on structures in the inner layers have been improved with their number increased in comparison with those at the surface and the interface layers. In addition, thermal annealing also helps the formation of P3HT face-on structures in the films, as evidenced by 2 dimensional GIXRD. Conclusion: The improved structures in these films lead to more charge transport channels formed to improve the carrier mobility, which in turn helps the improvement of OSCs. Thus, the present GIXRD results will improve the understanding of annealing effects at different depths of the P3HT/PCBM thin films for enhanced OSCs devices. (authors)

  9. MeV single-ion beam irradiation of mammalian cells using the Surrey vertical nanobeam, compared with broad proton beam and X-ray irradiations

    Science.gov (United States)

    Prakrajang, K.; Jeynes, J. C. G.; Merchant, M. J.; Kirkby, K.; Kirkby, N.; Thopan, P.; Yu, L. D.

    2013-07-01

    As a part of a systematic study on mechanisms involved in physical cancer therapies, this work investigated response of mammalian cells to ultra-low-dose ion beam irradiation. The ion beam irradiation was performed using the recently completed nanobeam facility at the Surrey Ion Beam Centre. A scanning focused vertical ion nano-beam was applied to irradiate Chinese hamster V79 cells. The V79 cells were irradiated in two different beam modes, namely, focused single ion beam and defocused scanning broad ion beam of 3.8-MeV protons. The single ion beam was capable of irradiating a single cell with a precisely controlled number of the ions to extremely low doses. After irradiation and cell incubation, the number of surviving colonies as a function of the number of the irradiating ions was measured for the cell survival fraction curve. A lower survival for the single ion beam irradiation than that of the broad beam case implied the hypersensitivity and bystander effect. The ion-beam-induced cell survival curves were compared with that from 300-kV X-ray irradiation. Theoretical studies indicated that the cell death in single ion irradiation mainly occurred in the cell cycle phases of cell division and intervals between the cell division and the DNA replication. The success in the experiment demonstrated the Surrey vertical nanobeam successfully completed.

  10. Stability and linearity of luminescence imaging of water during irradiation of proton-beams and X-ray photons lower energy than the Cerenkov light threshold

    Science.gov (United States)

    Yamamoto, Seiichi; Koyama, Shuji; Yabe, Takuya; Komori, Masataka; Tada, Junki; Ito, Shiori; Toshito, Toshiyuki; Hirata, Yuho; Watanabe, Kenichi

    2018-03-01

    Luminescence of water during irradiations of proton-beams or X-ray photons lower energy than the Cerenkov-light threshold is promising for range estimation or the distribution measurements of beams. However it is not yet obvious whether the intensities and distributions are stable with the water conditions such as temperature or addition of solvable materials. It remains also unclear whether the luminescence of water linearly increases with the irradiated proton or X-ray energies. Consequently we measured the luminescence of water during irradiations of proton-beam or X-ray photons lower energy than the Cerenkov-light threshold with different water conditions and energies to evaluate the stability and linearity of luminescence of water. We placed a water phantom set with a proton therapy or X-ray system, luminescence images of water with different conditions and energies were measured with a high-sensitivity cooled charge coupled device (CCD) camera during proton or X-ray irradiations to the water phantom. In the stability measurements, imaging was made for different temperatures of water and addition of inorganic and organic materials to water. In the linearity measurements for the proton, we irradiated with four different energies below Cerenkov light threshold. In the linearity measurements for the X-ray, we irradiated X-ray with different supplied voltages. We evaluated the depth profiles for the luminescence images and evaluated the light intensities and distributions. The results showed that the luminescence of water was quite stable with the water conditions. There were no significant changes of intensities and distributions with the different temperatures. Results from the linearity experiments showed that the luminescence of water linearly increased with their energies. We confirmed that luminescence of water is stable with conditions of water. We also confirmed that the luminescence of water linearly increased with their energies.

  11. Development of an x-ray beam line at the NSLS for studies in materials science using x-ray absorption spectroscopy: Annual progress report

    International Nuclear Information System (INIS)

    Sayers, D.E.

    1986-01-01

    Although only in operation since May, 1985, the X-11 participation research team (PRT) at the NSLS has already demonstrated that it is one of the leading centers of x-ray absorption spectroscopy (XAS). During this time, results have been obtained and programs initiated in a number of areas, for example: interfaces, including deposited metal-metal and metal-semiconductor systems, multilayers and ion implanted layers; electrochemical systems, including Pt electrode fuel cells, Ni oxide battery electrodes, conducting polymers, passivation and corrosion; catalysts, including highly-dispersed supported metal catalysts and zeolite systems; quasi-crystals, heavy fermion systems, uranium and neptunium compounds, rare gas clusters, disordered metals and semiconductors, ferroelectric transition; and, biological systems and related models, including synthetic porphyrins and a number of metalloproteins. In concert with these scientific results have been a number of developments involving the technique itself. These include implementation of unique optical systems on both the A and B lines for optical performance over their designed energy ranges, advances in experimental capability, particular in glancing angle studies, optimization of ion chambers for surface studies, the improvement of electron yield detectors, and improved software for data acquisition and analysis. This report emphasizes some of the research highlights and significant developments of our PRT which occurred during the past year. A detailed bibliography of papers and talks resulting from work done at our beamline and the progress reports for our PRT which were in the 1985 NSLS Annual Report are appended

  12. X-ray FEL based on harmonics generation and electron beam outcoupling

    Energy Technology Data Exchange (ETDEWEB)

    Litvinenko, V.N.; Burnham, B. [Duke Univ., Durham, NC (United States)

    1995-12-31

    Electron beam outcoupling was suggested by N. A. Vinokurov as a method of optics independent outcoupling for high power FELs. The bunching of the electron beam is provided in a master oscillator. The prebunched electron beam then radiates coherently into an additional wiggler called the radiator. The electron beam is turned by an achromatic bend into this wiggler and its radiation propagates with a small angle with respect to the OK-4 optical axis. Thus, the radiation will pass around the mirror of the master oscillator optical cavity and can then be utilized. This scheme is perfectly suited for harmonic generation if the radiator wiggler is tuned on one of the master oscillator wavelength harmonics. This system is reminiscent of a klystron operating on a harmonic of the reference frequency. In this paper we present the theory of this device, its spectral and spatial characteristics of radiation, the optimization of the master oscillator, the achromatic bend and bunching for harmonic generation, and influence of beam parameters (energy spread, emittance, etc.) on generated power. Examples of possible storage ring and linac driven systems are discussed.

  13. Computational modelling of the cerebral cortical microvasculature: effect of x-ray microbeams versus broad beam irradiation

    Science.gov (United States)

    Merrem, A.; Bartzsch, S.; Laissue, J.; Oelfke, U.

    2017-05-01

    Microbeam Radiation Therapy is an innovative pre-clinical strategy which uses arrays of parallel, tens of micrometres wide kilo-voltage photon beams to treat tumours. These x-ray beams are typically generated on a synchrotron source. It was shown that these beam geometries allow exceptional normal tissue sparing from radiation damage while still being effective in tumour ablation. A final biological explanation for this enhanced therapeutic ratio has still not been found, some experimental data support an important role of the vasculature. In this work, the effect of microbeams on a normal microvascular network of the cerebral cortex was assessed in computer simulations and compared to the effect of homogeneous, seamless exposures at equal energy absorption. The anatomy of a cerebral microvascular network and the inflicted radiation damage were simulated to closely mimic experimental data using a novel probabilistic model of radiation damage to blood vessels. It was found that the spatial dose fractionation by microbeam arrays significantly decreased the vascular damage. The higher the peak-to-valley dose ratio, the more pronounced the sparing effect. Simulations of the radiation damage as a function of morphological parameters of the vascular network demonstrated that the distribution of blood vessel radii is a key parameter determining both the overall radiation damage of the vasculature and the dose-dependent differential effect of microbeam irradiation.

  14. Proton- and x-ray beams generated by ultra-fast CO2 lasers for medical applications

    Science.gov (United States)

    Pogorelsky, Igor; Polyanskiy, Mikhail; Yakimenko, Vitaly; Ben-Zvi, Ilan; Shkolnikov, Peter; Najmudin, Zulfikar; Palmer, Charlotte A. J.; Dover, Nicholas P.; Oliva, Piernicola; Carpinelli, Massimo

    2011-05-01

    Recent progress in using picosecond CO2 lasers for Thomson scattering and ion-acceleration experiments underlines their potentials for enabling secondary radiation- and particle- sources. These experiments capitalize on certain advantages of long-wavelength CO2 lasers, such as higher number of photons per energy unit, and favorable scaling of the electrons' ponderomotive energy and critical plasma density. The high-flux x-ray bursts produced by Thomson scattering of the CO2 laser off a counter-propagating electron beam enabled high-contrast, time-resolved imaging of biological objects in the picosecond time frame. In different experiments, the laser, focused on a hydrogen jet, generated monoenergetic proton beams via the radiation-pressure mechanism. The strong power-scaling of this regime promises realization of proton beams suitable for laser-driven proton cancer therapy after upgrading the CO2 laser to sub-PW peak power. This planned improvement includes optimizing the 10-μm ultra-short pulse generation, assuring higher amplification in the CO2 gas under combined isotopic- and power-broadening effects, and shortening the postamplification pulse to a few laser cycles (150-200 fs) via chirping and compression. These developments will move us closer to practical applications of ultra-fast CO2 lasers in medicine and other areas.

  15. X-Ray Investigation and Strength Measurement of Steel Fibre Reinforced Self-Compacting Concrete Beams

    Directory of Open Access Journals (Sweden)

    Ponikiewski Tomasz

    2016-12-01

    Full Text Available The paper presents a study on self-compacting concrete with two types of steel fibres. Under consideration was the effect the method of forming of beam elements has on the distribution of steel fibres. Formed we beams of dimensions 120×15×15 cm3 and 180×15×15 cm3. The self-compacting mixture contained steel fibres of varying lengths (35 and 50 mm and varying levels of their volume ratio in the mix (0.5% - 1.0% - 1.5%.

  16. Characterisation by X-ray diffraction, electron microscopy and X-ray fluorescence of thin films obtained from evaporation of SmS. Crystallographic structures after annealing with electron beam

    International Nuclear Information System (INIS)

    Gasgnier, M.; Senateur, J.P.

    1980-01-01

    Thin films are obtained from divalent SmS evaporation under a vacuum of 10 -6 torr. The layers with a thickness of less than 1500 A are always amorphous. Those with a thickness of more than 2000 A present some properties varying according to the substrate temperature. The samples deposited at 85 K and slowly heated up to 293 K are black-grey and cristallized (f.c.c. structure, a = 5.91 A) which may be characteristic of the 2 + valence state for Sm. At 293 K, samples are yellow and poorly cristallized (f.c.c. structure, a = 5.58 A) which may be characteristic of the 3 + valence state for Sm. Crystallographic results are obtained by X-ray diffraction and electron diffraction. Analysis have been made by the X-ray fluorescence method. The electron beam permits to anneal the films and the following compounds appear: Sm 2 O 2 S, C and B-Sm 2 O 3 . At high temperature there is formation of new structures with large lattice parameters probably belonging to the Sm-O-S ternary system as X-ray fluorescence analysis shows it [fr

  17. Performance evaluation of X-ray CT using visible scintillation light

    International Nuclear Information System (INIS)

    Kodama, Kiyoyuki; Hamada, Minoru; Suzuki, Tamotsu; Hashimoto, Masatoshi; Hanada, Takashi; Ide, Tatsuya; Maruyama, Koichi

    2004-01-01

    We proposed a new method of performance evaluation for X-ray CT using visible scintillation light and examined its usefulness in this study. When we scanned a plastic scintillator disk in a gantry opening of the X-ray CT, we could observe visible scintillation light. The rotation of the light-emitting area of the disk corresponded to that of the X-ray tube. We were able to record the scintillation light by digital video camera. By analyzing the area of visible scintillation light, the rotation speed of the X-ray tube, angular spread of the X-ray beam, uniformity of the incident X-rays, and change in X-ray energy were measured. No other method is available to obtain the above parameters of X-ray CT during a single CT scan. In the measurements of the uniformity of incident X-rays and change of X-ray energy, our method showed good accuracy in detecting the attenuation caused by the couch between the X-ray tube and the plastic scintillator disc. The proposed method is inexpensive and easy-to-use. We conclude that the method is a useful tool for performance evaluation as well as a maintenance tool for X-ray CT. (author)

  18. X-ray Radiation Mechanisms and the Beaming Effect of Hot Spots ...

    Indian Academy of Sciences (India)

    2016-01-27

    -ray Radiation Mechanisms and the Beaming Effect of Hot Spots and Knots in AGN Jets. Jin Zhang Jin-Ming Bai Liang Chen Enwei Liang. Part 4. Emission Models and Theory Volume 32 Issue 1-2 March-June 2011 pp 193- ...

  19. Bone X-Ray (Radiography)

    Medline Plus

    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 that those parts of a patient's body not being imaged receive minimal radiation exposure. ...

  20. Detailed characterization of electron sources yielding first demonstration of European X-ray Free-Electron Laser beam quality

    Directory of Open Access Journals (Sweden)

    F. Stephan

    2010-02-01

    Full Text Available The photoinjector test facility at DESY, Zeuthen site (PITZ, was built to develop and optimize photoelectron sources for superconducting linacs for high-brilliance, short-wavelength free-electron laser (FEL applications like the free-electron laser in Hamburg (FLASH and the European x-ray free-electron laser (XFEL. In this paper, the detailed characterization of two laser-driven rf guns with different operating conditions is described. One experimental optimization of the beam parameters was performed at an accelerating gradient of about 43  MV/m at the photocathode and the other at about 60  MV/m. In both cases, electron beams with very high phase-space density have been demonstrated at a bunch charge of 1 nC and are compared with corresponding simulations. The rf gun optimized for the lower gradient has surpassed all the FLASH requirements on beam quality and rf parameters (gradient, rf pulse length, repetition rate and serves as a spare gun for this facility. The rf gun studied with increased accelerating gradient at the cathode produced beams with even higher brightness, yielding the first demonstration of the beam quality required for driving the European XFEL: The geometric mean of the normalized projected rms emittance in the two transverse directions was measured to be 1.26±0.13  mm mrad for a 1-nC electron bunch. When a 10% charge cut is applied excluding electrons from those phase-space regions where the measured phase-space density is below a certain level and which are not expected to contribute to the lasing process, the normalized projected rms emittance is about 0.9 mm mrad.

  1. A simple, direct method for x-ray scatter estimation and correction in digital radiography and cone-beam CT

    International Nuclear Information System (INIS)

    Siewerdsen, J.H.; Daly, M.J.; Bakhtiar, B.

    2006-01-01

    X-ray scatter poses a significant limitation to image quality in cone-beam CT (CBCT), resulting in contrast reduction, image artifacts, and lack of CT number accuracy. We report the performance of a simple scatter correction method in which scatter fluence is estimated directly in each projection from pixel values near the edge of the detector behind the collimator leaves. The algorithm operates on the simple assumption that signal in the collimator shadow is attributable to x-ray scatter, and the 2D scatter fluence is estimated by interpolating between pixel values measured along the top and bottom edges of the detector behind the collimator leaves. The resulting scatter fluence estimate is subtracted from each projection to yield an estimate of the primary-only images for CBCT reconstruction. Performance was investigated in phantom experiments on an experimental CBCT benchtop, and the effect on image quality was demonstrated in patient images (head, abdomen, and pelvis sites) obtained on a preclinical system for CBCT-guided radiation therapy. The algorithm provides significant reduction in scatter artifacts without compromise in contrast-to-noise ratio (CNR). For example, in a head phantom, cupping artifact was essentially eliminated, CT number accuracy was restored to within 3%, and CNR (breast-to-water) was improved by up to 50%. Similarly in a body phantom, cupping artifact was reduced by at least a factor of 2 without loss in CNR. Patient images demonstrate significantly increased uniformity, accuracy, and contrast, with an overall improvement in image quality in all sites investigated. Qualitative evaluation illustrates that soft-tissue structures that are otherwise undetectable are clearly delineated in scatter-corrected reconstructions. Since scatter is estimated directly in each projection, the algorithm is robust with respect to system geometry, patient size and heterogeneity, patient motion, etc. Operating without prior information, analytical modeling

  2. Time-resolved electron beam phase space tomography at a soft x-ray free-electron laser

    Directory of Open Access Journals (Sweden)

    Michael Röhrs

    2009-05-01

    Full Text Available High-gain free-electron lasers (FELs in the ultraviolet and x-ray regime put stringent demands on the peak current, transverse emittance, and energy spread of the driving electron beam. At the soft x-ray FEL FLASH, a transverse deflecting microwave structure (TDS has been installed to determine these parameters for the longitudinally compressed bunches, which are characterized by a narrow leading peak of high charge density and a long tail. The rapidly varying electromagnetic field in the TDS deflects the electrons vertically and transforms the time profile into a streak on an observation screen. The bunch current profile was measured single shot with an unprecedented resolution of 27 fs under FEL operating conditions. A precise single-shot measurement of the energy distribution along a bunch was accomplished by using the TDS in combination with an energy spectrometer. Variation of quadrupole strengths allowed for a determination of the horizontal emittance as a function of the longitudinal position within a bunch, the so-called slice emittance. In the bunch tail, a normalized slice emittance of about 2  μm was found, in agreement with expectations. In the leading spike, however, surprisingly large emittance values were observed, in apparent contradiction with the low emittance deduced from the measured FEL gain. By applying three-dimensional phase space tomography, we were able to show that the bunch head contains a central core of low emittance and high local current density, which is presumably the lasing part of the bunch.

  3. Directional fine structure in absorption of white x rays: A tomographic interpretation

    International Nuclear Information System (INIS)

    Korecki, P.; Szymonski, M.; Tolkiehn, M.; Novikov, D. V.; Materlik, G.

    2006-01-01

    We discuss directional fine structure in absorption of white x rays for tomographic imaging of crystal structure at the atomic level. The interference between a direct x-ray beam and the secondary waves coherently scattered inside a specimen modifies the total wave field at the position of the absorbing atoms. For a white x-ray beam, the wave field variations cancel out by energy integration for all directions, except for the near forward scattering components, coinciding with the incident beam. Therefore, two-dimensional patterns of the angular-dependent fine structure in absorption of white x rays can be interpreted as real-space projections of atomic structure. In this work, we present a theory describing the directional fine structure in white x-ray absorption and a tomographic approach for crystal structure retrieval developed on its basis. The tomographic algorithm is applied to the experimental x-ray absorption data recorded for GaP crystals

  4. Measurement of UO2 surface oxidation using grazing-incidence x-ray diffraction: Implications for nuclear forensics

    Science.gov (United States)

    Tracy, Cameron L.; Chen, Chien-Hung; Park, Sulgiye; Davisson, M. Lee; Ewing, Rodney C.

    2018-04-01

    Nuclear forensics involves determination of the origin and history of interdicted nuclear materials based on the detection of signatures associated with their production and trafficking. The surface oxidation undergone by UO2 when exposed to air is a potential signature of its atmospheric exposure during handling and transport. To assess the sensitivity of this oxidation to atmospheric parameters, surface sensitive grazing-incidence x-ray diffraction (GIXRD) measurements were performed on UO2 samples exposed to air of varying relative humidity (34%, 56%, and 95% RH) and temperature (room temperature, 50 °C, and 100 °C). Near-surface unit cell contraction was observed following exposure, indicating oxidation of the surface and accompanying reduction of the uranium cation ionic radii. The extent of unit cell contraction provides a measure of the extent of oxidation, allowing for comparison of the effects of various exposure conditions. No clear influence of relative humidity on the extent of oxidation was observed, with samples exhibiting similar degrees of unit cell contraction at all relative humidities investigated. In contrast, the thickness of the oxidized layers increased substantially with increasing temperature, such that differences on the order of 10 °C yielded readily observable crystallographic signatures of the exposure conditions.

  5. Investigation of surface and sub-surface damage in high quality synthetic diamonds by X-ray reflectivity and grazing incidence in-plane diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Bussone, Genziana; Lafford, Tamzin A.; Masiello, Fabio; Carbone, Gerardina; Schuelli, Tobias U.; Rommeveaux, Amparo Vivo; Haertwig, Juergen [European Synchrotron Radiation Facility, 6, Rue Jules Horowitz, BP 220, 38043 Grenoble Cedex 9 (France); Gibaud, Alain [Laboratoire PEC, Universite du Maine le Mans, Avenue Olivier Messiaen, 72 085 Le Mans (France); Connell, Simon H. [University of Johannesburg, cnr Kingsway Ave and University Rd, Auckland Park, 2006, Johannesburg (South Africa); Wormington, Matthew [Jordan Valley Semiconductors Inc., 8601 Cross Park Drive, Suite 200, Austin, TX 78754-4578 (United States)

    2011-11-15

    High quality single-crystal synthetic diamond is the most suitable material for selected X-ray optical applications in the latest generation X-ray light sources. Excellent heat handling properties, as well as low absorption, coupled with high perfection in the crystal bulk and very good surface quality, are crucial for such applications. In recent years, some progress has been made in the fields of surface treatments and growth techniques. Conventional scaife polishing is largely ineffective on the diamond (111) surface. To overcome this disadvantage, one possibility is to use the Hot Metal polishing technique. An investigation of surface and sub-surface damage of Hot Metal polished and cleaved surfaces, has been carried out using depth-sensitive non-destructive X-ray techniques. The near surface crystalline quality was studied as a function of depth using in-plane grazing incidence X-ray diffraction. Additionally, X-ray reflectivity was used to investigate the density, thickness and roughness of near-surface layers. The measurements enable us to estimate the thickness of the affected sub-surface layer. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Online diagnostics of time-resolved electron beam properties with femtosecond resolution for X-ray FELs

    International Nuclear Information System (INIS)

    Yan, Minjie

    2016-07-01

    The European X-ray Free-electron Laser (XFEL) puts high demands on the quality of the highbrightness driving electron beam with bunch lengths in the femtosecond regime. Longitudinal diagnostics is requested to optimize and control the longitudinal profile, the longitudinal phase space, the slice energy spread and the slice emittance of the electron bunch, all of which are crucial to the generation of Self-Amplified Spontaneous Emission (SASE). The high bunch repetition rate of the super-conducting accelerator renders diagnostic method that is (quasi) non-destructive to the generation of SASE possible. In this thesis, three online diagnostic sections utilizing transverse deflecting structures (TDS) have been designed for the European XFEL, providing access to all parameters of interest with a longitudinal resolution down to below 10 fs.The requirement on the non-destructive capability has been realized by the implementation of fast kickermagnets and off-axis screens, which has been validated experimentally using an installation of the same concept at the Free-electron Laser in Hamburg. A special slicing procedure has been developed to significantly enhance the accuracy of slice energy spread measurements. Suppression of coherence effects, which impede the beam imaging in the TDS diagnostics, has been first demonstrated experimentally using the spatial separation method with scintillator screens. Comparison of the results of emittance measurements using the quadrupole scan method with those using the multi-screen method has proved the reliability of the latter method, which has been modelled intensively for the European XFEL.

  7. Simulation of AZ-PN100 resist pattern fluctuation in X-ray lithography, including synchrotron beam polarization

    International Nuclear Information System (INIS)

    Scheckler, E.W.; Ogawa, Taro; Tanaka, Toshihiko; Takeda, Eiji; Oizumi, Hiroaki.

    1993-01-01

    A new simulation model for nanometer-scale pattern fluctuation in X-ray lithography is presented and applied to a study of AZ-PN100 negative chemical amplification resist. The exposure simulation considers polarized photons from a synchrotron radiation (SR) source. Monte Carlo simulation of Auger and photoelectron generation is followed by electron scattering simulation to determine the deposited energy distribution at the nanometer scale, including beam polarization effects. An acid-catalyst random walk model simulates the post-exposure bake (PEB) step. Fourier transform infrared (FTIR) spectroscopy and developed resist thickness measurements are used to fit PEB and rate models for AZ-PN100. A polymer removal model for development simulation predicts the macroscopic resist shape and pattern roughness. The simulated 3σ linewidth variation is in excess of 24 nm. Simulation also shows a detrimental effect if the beam polarization is perpendicular to the line. Simulation assuming a theoretical ideal exposure yields a 50 nm minimum line for standard process conditions. (author)

  8. Photo neutron dose equivalent rate in 15 MV X-ray beam from a Siemens Primus Linac.

    Science.gov (United States)

    Ghasemi, A; Pourfallah, T Allahverdi; Akbari, M R; Babapour, H; Shahidi, M

    2015-01-01

    Fast and thermal neutron fluence rates from a 15 MV X-ray beams of a Siemens Primus Linac were measured using bare and moderated BF3 proportional counter inside the treatment room at different locations. Fluence rate values were converted to dose equivalent rate (DER) utilizing conversion factors of American Association of Physicist in Medicine's (AAPM) report number 19. For thermal neutrons, maximum and minimum DERs were 3.46 × 10(-6) (3 m from isocenter in +Y direction, 0 × 0 field size) and 8.36 × 10(-8) Sv/min (in maze, 40 × 40 field size), respectively. For fast neutrons, maximum DERs using 9" and 3" moderators were 1.6 × 10(-5) and 1.74 × 10(-5) Sv/min (2 m from isocenter in +Y direction, 0 × 0 field size), respectively. By changing the field size, the variation in thermal neutron DER was more than the fast neutron DER and the changes in fast neutron DER were not significant in the bunker except inside the radiation field. This study showed that at all points and distances, by decreasing field size of the beam, thermal and fast neutron DER increases and the number of thermal neutrons is more than fast neutrons.

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

    International Nuclear Information System (INIS)

    Bayon, A.; Roca, M.

    1982-01-01

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

  10. Quantitative determination of alpha-quartz in airbone dust samples by X-ray diffraction

    International Nuclear Information System (INIS)

    Bayon, A.; Roca, M.

    1982-01-01

    The quantitative determination by X-ray diffractometry of alpha-quartz in airbone respirable dust samples on silver membrane filters is considered. A cobalt anode X-ray tube is employec. NiO is used as internal standard in order to compensate for both the variations of specimen absorption and the effect due to the nonuniformity of the incident X-ray beam and to the incomplete homogeneity on the filters of samples and standards. (auth.) [es

  11. Construction of a laboratory for the implantation of primary standardization of the magnitude kerma in the air for the X-ray beams used in mammography

    International Nuclear Information System (INIS)

    Cardozo, W.L.; Magalhes, L.A.A.M.F.; Peixoto, J.G.P.

    2009-01-01

    Aiming to diminish the uncertainty in each phase of the metrological chain, and the uncertainty in dosimetry processed at the X-ray beam applied in the mammography, is necessary that the LNMRI/IRD to develop a reference primary standard for the absolute form to the magnitude kerma in the air

  12. EFFECTS OF X-RAY BEAM ANGLE AND GEOMETRIC DISTORTION ON WIDTH OF EQUINE THORACOLUMBAR INTERSPINOUS SPACES USING RADIOGRAPHY AND COMPUTED TOMOGRAPHY

    DEFF Research Database (Denmark)

    Djernaes, Julie D.; Nielsen, Jon V.; Berg, Lise C.

    2017-01-01

    The widths of spaces between the thoracolumbar processi spinosi (interspinous spaces) are frequently assessed using radiography in sports horses; however effects of varying X-ray beam angles and geometric distortion have not been previously described. The aim of this prospective, observational st...

  13. Skull x-ray

    Science.gov (United States)

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

  14. Neck x-ray

    Science.gov (United States)

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

  15. Compact x-ray source and panel

    Science.gov (United States)

    Sampayon, Stephen E [Manteca, CA

    2008-02-12

    A compact, self-contained x-ray source, and a compact x-ray source panel having a plurality of such x-ray sources arranged in a preferably broad-area pixelized array. Each x-ray source includes an electron source for producing an electron beam, an x-ray conversion target, and a multilayer insulator separating the electron source and the x-ray conversion target from each other. The multi-layer insulator preferably has a cylindrical configuration with a plurality of alternating insulator and conductor layers surrounding an acceleration channel leading from the electron source to the x-ray conversion target. A power source is connected to each x-ray source of the array to produce an accelerating gradient between the electron source and x-ray conversion target in any one or more of the x-ray sources independent of other x-ray sources in the array, so as to accelerate an electron beam towards the x-ray conversion target. The multilayer insulator enables relatively short separation distances between the electron source and the x-ray conversion target so that a thin panel is possible for compactness. This is due to the ability of the plurality of alternating insulator and conductor layers of the multilayer insulators to resist surface flashover when sufficiently high acceleration energies necessary for x-ray generation are supplied by the power source to the x-ray sources.

  16. Molecular beam epitaxy of GeTe-Sb{sub 2}Te{sub 3} phase change materials studied by X-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Shayduk, Roman

    2010-05-20

    The integration of phase change materials into semiconductor heterostructures may lead to the development of a new generation of high density non-volatile phase change memories. Epitaxial phase change materials allow to study the detailed structural changes during the phase transition and to determine the scaling limits of the memory. This work is dedicated to the epitaxial growth of Ge-Sb-Te phase change alloys on GaSb(001). We deposit Ge-Sb-Te (GST) films on GaSb(001) substrates by means of molecular beam epitaxy (MBE). The film orientation and lattice constant evolution is determined in real time during growth using grazing incidence X-ray diffraction (GID). The nucleation stage of the growth is studied in situ using reflection high energy electron diffraction (RHEED). Four growth regimes of GST on GaSb(001) were observed: amorphous, polycrystalline, incubated epitaxial and direct epitaxial. Amorphous film grows for substrate temperatures below 100 C. For substrate temperatures in the range 100-160 C, the film grows in polycrystalline form. Incubated epitaxial growth is observed at temperatures from 180 to 210 C. This growth regime is characterized by an initial 0.6nm thick amorphous layer formation, which crystallizes epitaxially as the film thickness increases. The determined lattice constant of the films is 6.01 A, very close to that of the metastable GST phase. The films predominantly possess an epitaxial cube-on-cube relationship. At higher temperatures the films grow epitaxially, however the growth rate is rapidly decreasing with temperature. At temperatures above 270 C the growth rate is zero. The composition of the grown films is close to 2:2:5 for Ge, Sb and Te, respectively. The determined crystal structure of the films is face centered cubic (FCC) with a rhombohedral distortion. The analysis of X-ray peak widths gives a value for the rhombohedral angle of 89.56 . We observe two types of reflections in reciprocal space indicating two FCC sublattices in

  17. Development of an x-ray Talbot-Lau moire deflectometer for fast density profile measurements of dense plasmas generated by beam-target interactions

    Energy Technology Data Exchange (ETDEWEB)

    Clayton, Dan [National Security Technol., LLC, Los Alamos, NM (United States); Berninger, M; Meidinger, A; Stutman, Dan; Valdivia, Maria Pia

    2015-05-01

    For the first time an x-ray Talbot-Lau moire deflectometer is being developed that will use a flash tube source and fast detector for dynamic density gradient measurements. In Talbot-Lau moire deflectometry, an x-ray grating makes an image of itself on a second grating (the Talbot effect) to produce a moire pattern on a detector. The test object is placed between these gratings, with variations in index of refraction changing the pattern. A third grating in front of an incoherent x-ray source produces an array of coherent sources. With a 150 kV x-ray flash tube as the source, the gratings are placed in a glancing angle setup for performance at ~60 keV. The detector is a gated CCD with a fast scintillator for x-ray conversion. This diagnostic, designed for the Dual-Axis Radiographic Hydrodynamic Test facility (DARHT) at Los Alamos National Laboratory, measures the density profile of dense plasma plumes ejected from beam-target interactions. DARHT has two high-current, pulsed, inductive linear electron accelerators with bremsstrahlung targets at the end of each beam line to create 2-D radiographic images of hydrodynamic tests. One multi-pulse accelerator has up to four beam pulses striking the same target within 2 μs. Computer simulations that model target evolution and ejected material between pulses are used to design these targets for optimal radiographic performance; the x-ray deflectometer will directly measure density gradients in the ejected plumes and provide the first experimental constraints to these models. During the first year, currently underway, the diagnostic systems are being designed. In year two, the flash tube and fast detector will be deployed at DARHT for radiographic imaging while the deflectometer is built and tested on the bench with a continuous source. Finally, in year three, the fast deflectometer will be installed on DARHT and density measurements will be performed.

  18. A new X-ray fluorescence spectroscopy for extraterrestrial materials using a muon beam.

    Science.gov (United States)

    Terada, K; Ninomiya, K; Osawa, T; Tachibana, S; Miyake, Y; Kubo, M K; Kawamura, N; Higemoto, W; Tsuchiyama, A; Ebihara, M; Uesugi, M

    2014-05-27

    The recent development of the intense pulsed muon source at J-PARC MUSE, Japan Proton Accelerator Research Complex/MUon Science Establishment (10(6) s(-1) for a momentum of 60 MeV/c), enabled us to pioneer a new frontier in analytical sciences. Here, we report a non-destructive elemental analysis using µ(-) capture. Controlling muon momentum from 32.5 to 57.5 MeV/c, we successfully demonstrate a depth-profile analysis of light elements (B, C, N, and O) from several mm-thick layered materials and non-destructive bulk analyses of meteorites containing organic materials. Muon beam analysis, enabling a bulk analysis of light to heavy elements without severe radioactivation, is a unique analytical method complementary to other non-destructive analyses. Furthermore, this technology can be used as a powerful tool to identify the content and distribution of organic components in future asteroidal return samples.

  19. Characterization of Scattered X-Ray Photons in Dental Cone-Beam Computed Tomography.

    Directory of Open Access Journals (Sweden)

    Ching-Ching Yang

    Full Text Available Scatter is a very important artifact causing factor in dental cone-beam CT (CBCT, which has a major influence on the detectability of details within images. This work aimed to improve the image quality of dental CBCT through scatter correction.Scatter was estimated in the projection domain from the low frequency component of the difference between the raw CBCT projection and the projection obtained by extrapolating the model fitted to the raw projections acquired with 2 different sizes of axial field-of-view (FOV. The function for curve fitting was optimized by using Monte Carlo simulation. To validate the proposed method, an anthropomorphic phantom and a water-filled cylindrical phantom with rod inserts simulating different tissue materials were scanned using 120 kVp, 5 mA and 9-second scanning time covering an axial FOV of 4 cm and 13 cm. The detectability of the CT image was evaluated by calculating the contrast-to-noise ratio (CNR.Beam hardening and cupping artifacts were observed in CBCT images without scatter correction, especially in those acquired with 13 cm FOV. These artifacts were reduced in CBCT images corrected by the proposed method, demonstrating its efficacy on scatter correction. After scatter correction, the image quality of CBCT was improved in terms of target detectability which was quantified as the CNR for rod inserts in the cylindrical phantom.Hopefully the calculations performed in this work can provide a route to reach a high level of diagnostic image quality for CBCT imaging used in oral and maxillofacial structures whilst ensuring patient dose as low as reasonably achievable, which may ultimately make CBCT scan a reliable and safe tool in clinical practice.

  20. Analysis of the additional filtration effects in X-ray beams from the calculation of average energy for photon in X-ray spectra; Analise dos efeitos da filtracao adicional em feixes de raios X a partir dos calculos de energia media por foton em espectros de raios X

    Energy Technology Data Exchange (ETDEWEB)

    Lucena, Rodrigo F.; Potiens, Maria da Penha A., E-mail: rodrigoifusp@yahoo.com.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-12-15

    The objective of this work was to analyze the behavior of X-ray spectra by calculating the average energy in each spectrum generated for different additional filtrations inserted in the X-ray beam. It was used an X-ray system present in the Laboratory of Instruments Calibration of the Instituto de Pesquisas Energeticas e Nucleares (IPEN) for the generation of X-ray beams, a spectrometry system with a solid state detector (semiconductor) to the data acquisition and aluminum and copper filters, with different thicknesses to be inserted in the output of the X-ray tube. The average energy per photon was calculated integrating the curve of each spectrum and dividing the value by the total number of counts. This calculation enabled to verify that the use of filtration in the X-ray equipment contributes significantly in the average energy of the X-ray beam. Thus, the same dose received by a patient or recorded by a detector has distinct average energies due to the use of filtrations with different materials and thicknesses, which allows the manipulation of X-ray beam through additional filtration. (author)

  1. Monte Carlo simulation applied in total reflection x-ray fluorescence: Preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Meira, Luiza L. C.; Inocente, Guilherme F.; Vieira, Leticia D.; Mesa, Joel [Departamento de Fisica e Biofisica - Instituto de Biociencias de Botucatu, Universidade Estadual Paulista Julio de Mesquita Filho (Brazil)

    2013-05-06

    The X-ray Fluorescence (XRF) analysis is a technique for the qualitative and quantitative determination of chemical constituents in a sample. This method is based on detection of the characteristic radiation intensities emitted by the elements of the sample, when properly excited. A variant of this technique is the Total Reflection X-ray Fluorescence (TXRF) that utilizes electromagnetic radiation as excitation source. In total reflection of X-ray, the angle of refraction of the incident beam tends to zero and the refracted beam is tangent to the sample support interface. Thus, there is a minimum angle of incidence at which no refracted beam exists and all incident radiation undergoes total reflection. In this study, we evaluated the influence of the energy variation of the beam of incident x-rays, using the MCNPX code (Monte Carlo NParticle) based on Monte Carlo method.

  2. Monte Carlo simulation applied in total reflection x-ray fluorescence: Preliminary results

    Science.gov (United States)

    Meira, Luiza L. C.; Inocente, Guilherme F.; Vieira, Letícia D.; Mesa, Joel

    2013-05-01

    The X-ray Fluorescence (XRF) analysis is a technique for the qualitative and quantitative determination of chemical constituents in a sample. This method is based on detection of the characteristic radiation intensities emitted by the elements of the sample, when properly excited. A variant of this technique is the Total Reflection X-ray Fluorescence (TXRF) that utilizes electromagnetic radiation as excitation source. In total reflection of X-ray, the angle of refraction of the incident beam tends to zero and the refracted beam is tangent to the sample support interface. Thus, there is a minimum angle of incidence at which no refracted beam exists and all incident radiation undergoes total reflection. In this study, we evaluated the influence of the energy variation of the beam of incident x-rays, using the MCNPX code (Monte Carlo NParticle) based on Monte Carlo method.

  3. Boro-Silicate Polycapillary Lens for Collimation of X-Rays

    National Research Council Canada - National Science Library

    Chase, Michael

    1997-01-01

    .... The electron beam was deflected 30 degrees using a rare earth permanent magnet. The diverging x-rays incident upon the lens array were transported through total external reflection and directed out of the array onto a phosphor screen...

  4. Bone X-Ray (Radiography)

    Medline Plus

    Full Text Available ... procedure. You may experience discomfort from the cool temperature in the examination room. You may also find ... have very controlled x-ray beams and dose control methods to minimize stray (scatter) radiation. This ensures ...

  5. Determination of the ReA Electron Beam Ion Trap electron beam radius and current density with an X-ray pinhole camera

    Energy Technology Data Exchange (ETDEWEB)

    Baumann, Thomas M., E-mail: baumannt@nscl.msu.edu; Lapierre, Alain, E-mail: lapierre@nscl.msu.edu; Kittimanapun, Kritsada; Schwarz, Stefan; Leitner, Daniela; Bollen, Georg [National Superconducting Cyclotron Laboratory (NSCL), Michigan State University (MSU), 640 S. Shaw Lane, East Lansing, Michigan, 48824 (United States)

    2014-07-15

    The Electron Beam Ion Trap (EBIT) of the National Superconducting Cyclotron Laboratory at Michigan State University is used as a charge booster and injector for the currently commissioned rare isotope re-accelerator facility ReA. This EBIT charge breeder is equipped with a unique superconducting magnet configuration, a combination of a solenoid and a pair of Helmholtz coils, allowing for a direct observation of the ion cloud while maintaining the advantages of a long ion trapping region. The current density of its electron beam is a key factor for efficient capture and fast charge breeding of continuously injected, short-lived isotope beams. It depends on the radius of the magnetically compressed electron beam. This radius is measured by imaging the highly charged ion cloud trapped within the electron beam with a pinhole camera, which is sensitive to X-rays emitted by the ions with photon energies between 2 keV and 10 keV. The 80%-radius of a cylindrical 800 mA electron beam with an energy of 15 keV is determined to be r{sub 80%}=(212±19)μm in a 4 T magnetic field. From this, a current density of j = (454 ± 83)A/cm{sup 2} is derived. These results are in good agreement with electron beam trajectory simulations performed with TriComp and serve as a test for future electron gun design developments.

  6. X-ray polarimetry with a conventional gas proportional counter through rise-time analysis

    CERN Document Server

    Hayashida, K; Tsunemi, H; Torii, K; Murakami, H; Ohno, Y; Tamura, K

    1999-01-01

    We have performed an experiment on the signal rise time of a Xe gas proportional counter using a polarized X-ray beam of synchrotron orbital radiation with energies from 10 to 40 keV. When the counter anode is perpendicular to the electric vector of the incident X-ray photons, the average rise time becomes significantly longer than that for the parallel case. This indicates that the conventional gas proportional counters are useful for X-ray polarimetry. The moderate modulation contrast of this rise-time polarimeter (M=0.1 for 10 keV X-rays and M=0.35 for 40 keV X-rays), with capability of the simultaneous measuring X-ray energies and the timing, would be useful for applications in X-ray astronomy and in other fields.

  7. An external proton beam at VERA to study objects of art by proton induced x-ray emission (PIXE)

    International Nuclear Information System (INIS)

    Kroepfl, P.; Forstner, O.; Kutschera, W.; Priller, A.; Steier, P.; Wallner, A.; Wuenschek, B.; Golser, R.

    2006-01-01

    Full text: PIXE is a very sensitive analytical method to determine the chemical composition of art objects, e.g. drawings, handwritings etc. A particular advantage is the possibility to analyze objects non-destructively under atmospheric pressure. Such an external beam PIXE facility is currently implemented at the Vienna Environmental Research Accelerator (VERA). The set-up allows to extract a 3 MeV proton beam of approximately 100 μm in diameter and currents in the range of a few nA's through an ultra-thin (0.1 μm) Silicon Nitride window. The characteristic x-rays emitted from the specimen are recorded with a Si(Li) and a Silicon Drift detector simultaneously to cover the widest possible Z-range of the detected elements. We have just completed an extensive period of studying beam effects on ancient paper to exclude possible damage to art objects, in particular drawings of the Renaissance that are among the most precious and rarest treasuries of graphical collections. They were created with different materials such as inks, chalks and metal points. A large collection of these fine arts objects is situated at the Albertina in Vienna. Together with scientists from the Centre de Recherche et de Restauration des Musees de France (C2RMF) in Paris, I. Reiche, A. Duval, H. Guicharnaud, from the CEREGE UMR CNRS 6635 in Aix-en-Provence, S. Merchel, from the Albertina in Vienna, E. Thobois, H. Singer, and from the Akademie der bildenden Kuenste in Vienna, M. Schreiner, we want then to analyze a few selected silverpoint drawings by Albrecht Duerer (1471-1528). (author)

  8. Efficient focusing of 8 keV X-rays with multilayer Fresnel zone plates fabricated by atomic layer deposition and focused ion beam milling

    International Nuclear Information System (INIS)

    Mayer, Marcel; Keskinbora, Kahraman; Grévent, Corinne; Szeghalmi, Adriana; Knez, Mato; Weigand, Markus; Snigirev, Anatoly; Snigireva, Irina; Schütz, Gisela

    2013-01-01

    The fabrication and performance of multilayer Al 2 O 3 /Ta 2 O 5 Fresnel zone plates in the hard X-ray range and a discussion of possible future developments considering available materials are reported. Fresnel zone plates (FZPs) recently showed significant improvement by focusing soft X-rays down to ∼10 nm. In contrast to soft X-rays, generally a very high aspect ratio FZP is needed for efficient focusing of hard X-rays. Therefore, FZPs had limited success in the hard X-ray range owing to difficulties of manufacturing high-aspect-ratio zone plates using conventional techniques. Here, employing a method of fabrication based on atomic layer deposition (ALD) and focused ion beam (FIB) milling, FZPs with very high aspect ratios were prepared. Such multilayer FZPs with outermost zone widths of 10 and 35 nm and aspect ratios of up to 243 were tested for their focusing properties at 8 keV and shown to focus hard X-rays efficiently. This success was enabled by the outstanding layer quality thanks to ALD. Via the use of FIB for slicing the multilayer structures, desired aspect ratios could be obtained by precisely controlling the thickness. Experimental diffraction efficiencies of multilayer FZPs fabricated via this combination reached up to 15.58% at 8 keV. In addition, scanning transmission X-ray microscopy experiments at 1.5 keV were carried out using one of the multilayer FZPs and resolved a 60 nm feature size. Finally, the prospective of different material combinations with various outermost zone widths at 8 and 17 keV is discussed in the light of the coupled wave theory and the thin-grating approximation. Al 2 O 3 /Ir is outlined as a promising future material candidate for extremely high resolution with a theoretical efficiency of more than 20% for as small an outermost zone width as 10 nm at 17 keV

  9. 100 ps time-resolved solution scattering utilizing a wide-bandwidth X-ray beam from multilayer optics

    International Nuclear Information System (INIS)

    Ichiyanagi, K.; Sato, T.; Nozawa, S.; Kim, K. H.; Lee, J. H.; Choi, J.; Tomita, A.; Ichikawa, H.; Adachi, S.; Ihee, H.; Koshihara, S.

    2009-01-01

    A new method of time-resolved solution scattering utilizing X-ray multilayer optics is presented. 100 ps time-resolved X-ray solution-scattering capabilities have been developed using multilayer optics at the beamline NW14A, Photon Factory Advanced Ring, KEK. X-ray pulses with an energy bandwidth of ΔE/E = 1–5% are generated by reflecting X-ray pulses (ΔE/E = 15%) through multilayer optics, made of W/B 4 C or depth-graded Ru/C on silicon substrate. This tailor-made wide-bandwidth X-ray pulse provides high-quality solution-scattering data for obtaining photo-induced molecular reaction dynamics. The time-resolved solution scattering of CH 2 I 2 in methanol is demonstrated as a typical example

  10. In-phantom measurement of absorbed dose to water in medium energy x-ray beams

    International Nuclear Information System (INIS)

    Hohlfeld, K.

    1996-01-01

    Absorbed dose values in a water phantom derived by the formalism of the IAEA Code of Practice of Absorbed Dose Determination in Photon and Electron Beams are a few per cent higher than those based on the procedure following e.g. ICRU Report 23. The maximum deviation exceeds 10% at 100 kV tube potential. The correction factor needed to take into account the differences at the calibration in terms of air kerma free in air and at the measurement in the water phantom can be determined in different ways: In comparing the result of the absorbed dose measurement by means of the ionization chambers with an other, preferably fundamental method of measurement of absorbed dose in the water phantom or by evaluating all component parts of the correction factor separately. The values of the perturbation correction factor in the IAEA Code were determined in the former way by comparing against a graphite extrapolation chamber. A review is given on a recent re-evaluation using former values of the extrapolation chamber measurements and on new determinations using an absorbed dose water calorimeter, a method based on calculated and measured air kerma values and a method of combining the component factors to the overall correction factor. Recent results achieved by the different methods are compared and a change of the data of the IAEA Code is recommended. (author). 31 refs, 14 figs, 3 tabs

  11. A feasibility study of dynamic stress analysis inside a running internal combustion engine using synchrotron X-ray beams.

    Science.gov (United States)

    Baimpas, Nikolaos; Drakopoulos, Michael; Connolley, Thomas; Song, Xu; Pandazaras, Costas; Korsunsky, Alexander M

    2013-03-01

    The present investigation establishes the feasibility of using synchrotron-generated X-ray beams for time-resolved in situ imaging and diffraction of the interior components of an internal combustion engine during its operation. The demonstration experiment was carried out on beamline I12 (JEEP) at Diamond Light Source, UK. The external hutch of the JEEP instrument is a large-scale engineering test bed for complex in situ processing and simulation experiments. The hutch incorporates a large capacity translation and rotation table and a selection of detectors for monochromatic and white-beam diffraction and imaging. These capabilities were used to record X-ray movies of a motorcycle internal combustion engine running at 1850 r.p.m. and to measure strain inside the connecting rod via stroboscopic X-ray diffraction measurement. The high penetrating ability and high flux of the X-ray beam at JEEP allowed the observation of inlet and outlet valve motion, as well as that of the piston, connecting rod and the timing chain within the engine. Finally, the dynamic internal strain within the moving connecting rod was evaluated with an accuracy of ~50 × 10(-6).

  12. Study of residual stresses i electron-beam welded F82H modified martensitic steel using X-ray and neutron diffraction

    International Nuclear Information System (INIS)

    Coppola, R.; Braham, C.; Ceretti, M.

    1998-01-01

    Ferritic/martensitic steels are presently considered as one of the most realistic options for the construction of the 'first-wall' and other components in future fusion reactors. More specifically the modified martensitic Chromium steel F82H is being characterised as a reference material in view of a possible utilisation in the DEMO reactor. This work presents the results of a study, carried out using X-ray and neutron diffraction to investigate the stress field in a prototype F82H-mod. weld obtained using the electron-beam welding technique. The stress has been measured, both with X-rays and neutrons, at different distances from the heat-affected zone. The differences between the results obtained with X-ray and neutron diffraction are tentatively discussed in terms of phase inhomogeneity inside the HAZ. (author)

  13. Impact of Lipid Oxidization on Vertical Structures and Electrostatics of Phospholipid Monolayers Revealed by Combination of Specular X-ray Reflectivity and Grazing-Incidence X-ray Fluorescence.

    Science.gov (United States)

    Korytowski, Agatha; Abuillan, Wasim; Makky, Ali; Konovalov, Oleg; Tanaka, Motomu

    2015-07-30

    The influence of phospholipid oxidization of floating monolayers on the structure perpendicular to the global plane and on the density profiles of ions near the lipid monolayer has been investigated by a combination of grazing incidence X-ray fluorescence (GIXF) and specular X-ray reflectivity (XRR). Systematic variation of the composition of the floating monolayers unravels changes in the thickness, roughness and electron density of the lipid monolayers as a function of molar fraction of oxidized phospholipids. Simultaneous GIXF measurements enable one to qualitatively determine the element-specific density profiles of monovalent (K(+) or Cs(+)) and divalent ions (Ca(2+)) in the vicinity of the interface in the presence and absence of two types of oxidized phospholipids (PazePC and PoxnoPC) with high spatial accuracy (±5 Å). We found the condensation of Ca(2+) near carboxylated PazePC was more pronounced compared to PoxnoPC with an aldehyde group. In contrast, the condensation of monovalent ions could hardly be detected even for pure oxidized phospholipid monolayers. Moreover, pure phospholipid monolayers exhibited almost no ion specific condensation near the interface. The quantitative studies with well-defined floating monolayers revealed how the elevation of lipid oxidization level alters the structures and functions of cell membranes.

  14. Extrapolated surface dose measurements using a NdFeB magnetic deflector for 6 MV x-ray beams.

    Science.gov (United States)

    Damrongkijudom, N; Butson, M; Rosenfeld, A

    2007-03-01

    Extrapolated surface dose measurements have been performed using radiographic film to measure 2-Dimensional maps of skin and surface dose with and without a magnetic deflector device aimed at reducing surface dose. Experiments are also performed using an Attix parallel plate ionisation chamber for comparison to radiographic film extrapolation surface dose analysis. Extrapolated percentage surface dose assessments from radiographic film at the central axis of a 6 MV x-ray beam with magnetic deflector for field size 10 x 10 cm2, 15 x 15 cm2 and 20 x 20 cm2 are 9 +/- 3%, 13 +/- 3% and 16 +/- 3%, these compared to 14 +/- 3%, 19 +/- 3%, and 27 +/- 3% for open fields, respectively. Results from Attix chamber for the same field size are 12 +/- 1%, 15 +/- 1% and 18 +/- 1%, these compared to 16 +/- 1%, 21 +/- 1% and 27 +/- 1% for open fields, respectively. Results are also shown for profiles measured in-plane and cross-plane to the magnetic deflector and compared to open field data. Results have shown that the surface dose is reduced at all sites within the treatment field with larger reductions seen on one side of the field due to the sweeping nature of the designed magnetic field. Radiographic film extrapolation provides an advanced surface dose assessment and has matched well with Attix chamber results. Film measurement allows for easy 2 dimensional dose assessments.

  15. Characterisation of edgeless technologies for pixellated and strip silicon detectors with a micro-focused X-ray beam

    Science.gov (United States)

    Bates, R.; Blue, A.; Christophersen, M.; Eklund, L.; Ely, S.; Fadeyev, V.; Gimenez, E.; Kachkanov, V.; Kalliopuska, J.; Macchiolo, A.; Maneuski, D.; Phlips, B. F.; Sadrozinski, H. F.-W.; Stewart, G.; Tartoni, N.; Zain, R. M.

    2013-01-01

    Reduced edge or ``edgeless'' detector design offers seamless tileability of sensors for a wide range of applications from particle physics to synchrotron and free election laser (FEL) facilities and medical imaging. Combined with through-silicon-via (TSV) technology, this would allow reduced material trackers for particle physics and an increase in the active area for synchrotron and FEL pixel detector systems. In order to quantify the performance of different edgeless fabrication methods, 2 edgeless detectors were characterized at the Diamond Light Source using an 11 μm FWHM 15 keV micro-focused X-ray beam. The devices under test were: a 150 μm thick silicon active edge pixel sensor fabricated at VTT and bump-bonded to a Medipix2 ROIC; and a 300 μm thick silicon strip sensor fabricated at CIS with edge reduction performed by SCIPP and the NRL and wire bonded to an ALiBaVa readout system. Sub-pixel resolution of the 55 μm active edge pixels was achieved. Further scans showed no drop in charge collection recorded between the centre and edge pixels, with a maximum deviation of 5% in charge collection between scanned edge pixels. Scans across the cleaved and standard guard ring edges of the strip detector also show no reduction in charge collection. These results indicate techniques such as the scribe, cleave and passivate (SCP) and active edge processes offer real potential for reduced edge, tiled sensors for imaging detection applications.

  16. Parallel statistical image reconstruction for cone-beam x-ray CT on a shared memory computation platform

    International Nuclear Information System (INIS)

    Kole, J S; Beekman, F J

    2005-01-01

    Statistical reconstruction methods offer possibilities of improving image quality as compared to analytical methods, but current reconstruction times prohibit routine clinical applications. To reduce reconstruction times we have parallelized a statistical reconstruction algorithm for cone-beam x-ray CT, the ordered subset convex algorithm (OSC), and evaluated it on a shared memory computer. Two different parallelization strategies were developed: one that employs parallelism by computing the work for all projections within a subset in parallel, and one that divides the total volume into parts and processes the work for each sub-volume in parallel. Both methods are used to reconstruct a three-dimensional mathematical phantom on two different grid densities. The reconstructed images are binary identical to the result of the serial (non-parallelized) algorithm. The speed-up factor equals approximately 30 when using 32 to 40 processors, and scales almost linearly with the number of cpus for both methods. The huge reduction in computation time allows us to apply statistical reconstruction to clinically relevant studies for the first time

  17. Library based x-ray scatter correction for dedicated cone beam breast CT

    International Nuclear Information System (INIS)

    Shi, Linxi; Zhu, Lei; Vedantham, Srinivasan; Karellas, Andrew

    2016-01-01

    Purpose: The image quality of dedicated cone beam breast CT (CBBCT) is limited by substantial scatter contamination, resulting in cupping artifacts and contrast-loss in reconstructed images. Such effects obscure the visibility of soft-tissue lesions and calcifications, which hinders breast cancer detection and diagnosis. In this work, we propose a library-based software approach to suppress scatter on CBBCT images with high efficiency, accuracy, and reliability. Methods: The authors precompute a scatter library on simplified breast models with different sizes using the GEANT4-based Monte Carlo (MC) toolkit. The breast is approximated as a semiellipsoid with homogeneous glandular/adipose tissue mixture. For scatter correction on real clinical data, the authors estimate the breast size from a first-pass breast CT reconstruction and then select the corresponding scatter distribution from the library. The selected scatter distribution from simplified breast models is spatially translated to match the projection data from the clinical scan and is subtracted from the measured projection for effective scatter correction. The method performance was evaluated using 15 sets of patient data, with a wide range of breast sizes representing about 95% of general population. Spatial nonuniformity (SNU) and contrast to signal deviation ratio (CDR) were used as metrics for evaluation. Results: Since the time-consuming MC simulation for library generation is precomputed, the authors’ method efficiently corrects for scatter with minimal processing time. Furthermore, the authors find that a scatter library on a simple breast model with only one input parameter, i.e., the breast diameter, sufficiently guarantees improvements in SNU and CDR. For the 15 clinical datasets, the authors’ method reduces the average SNU from 7.14% to 2.47% in coronal views and from 10.14% to 3.02% in sagittal views. On average, the CDR is improved by a factor of 1.49 in coronal views and 2.12 in sagittal

  18. Library based x-ray scatter correction for dedicated cone beam breast CT.

    Science.gov (United States)

    Shi, Linxi; Vedantham, Srinivasan; Karellas, Andrew; Zhu, Lei

    2016-08-01

    The image quality of dedicated cone beam breast CT (CBBCT) is limited by substantial scatter contamination, resulting in cupping artifacts and contrast-loss in reconstructed images. Such effects obscure the visibility of soft-tissue lesions and calcifications, which hinders breast cancer detection and diagnosis. In this work, we propose a library-based software approach to suppress scatter on CBBCT images with high efficiency, accuracy, and reliability. The authors precompute a scatter library on simplified breast models with different sizes using the geant4-based Monte Carlo (MC) toolkit. The breast is approximated as a semiellipsoid with homogeneous glandular/adipose tissue mixture. For scatter correction on real clinical data, the authors estimate the breast size from a first-pass breast CT reconstruction and then select the corresponding scatter distribution from the library. The selected scatter distribution from simplified breast models is spatially translated to match the projection data from the clinical scan and is subtracted from the measured projection for effective scatter correction. The method performance was evaluated using 15 sets of patient data, with a wide range of breast sizes representing about 95% of general population. Spatial nonuniformity (SNU) and contrast to signal deviation ratio (CDR) were used as metrics for evaluation. Since the time-consuming MC simulation for library generation is precomputed, the authors' method efficiently corrects for scatter with minimal processing time. Furthermore, the authors find that a scatter library on a simple breast model with only one input parameter, i.e., the breast diameter, sufficiently guarantees improvements in SNU and CDR. For the 15 clinical datasets, the authors' method reduces the average SNU from 7.14% to 2.47% in coronal views and from 10.14% to 3.02% in sagittal views. On average, the CDR is improved by a factor of 1.49 in coronal views and 2.12 in sagittal views. The library-based scatter

  19. Quasimonochromatic x-ray computed tomography by the balanced filter method using a conventional x-ray source

    International Nuclear Information System (INIS)

    Saito, Masatoshi

    2004-01-01

    A quasimonochromatic x-ray computed tomography (CT) system utilizing balanced filters has recently been developed for acquiring quantitative CT images. This system consisted of basic components such as a conventional x-ray generator for radiography, a stage for mounting and rotating objects, and an x-ray line sensor camera. Metallic sheets of Er and Yb were used as the balanced filters for obtaining quasimonochromatic incident x rays that include the characteristic lines of the W Kα doublet from a tungsten target. The mean energy and energy width of the quasimonochromatic x rays were determined to be 59.0 and 1.9 keV, respectively, from x-ray spectroscopic measurements using a high-purity Ge detector. The usefulness of the present x-ray CT system was demonstrated by obtaining spatial distributions of the linear attenuation coefficients of three selected samples--a 20 cm diameter cylindrical water phantom, a 3.5 cm diameter aluminum rod, and a human head phantom. The results clearly indicate that this apparatus is surprisingly effective for estimating the distribution of the linear attenuation coefficients without any correction of the beam-hardening effect. Thus, implementing the balanced filter method on an x-ray CT scanner has promise in producing highly quantitative CT images

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

    Science.gov (United States)

    Pelliccia, Daniele; Paganin, David M

    2013-04-22

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

  1. Morphology of bone defects in patient with unilateral cleft lip and palate. Cone beam x-ray CT evaluation

    International Nuclear Information System (INIS)

    Kyo, Iyu; Kubota, Masato; Sato, Yuki; Nakano, Haruhisa; Maki, Koutaro

    2006-01-01

    Orthodontic treatment planning of the cleft lip and palate vary according to the morphology of the alveolar bone and palatal bone. The purpose of this study is to evaluate the three-dimensional anatomy of the alveolar and palatal bone in children with complete unilateral cleft lip and palate. Thirty-three nonsyndromic consecutive patients with complete unilateral cleft lip and palate were treated by the cleft palate team at Showa University. Each patient had lip and palate surgeries at Showa University. Cone beam CT radiographs (CB MercuRay, Hitachi) were taken prior to secondary bone grafting, and were classified according to the method of Kita et al. 1997. Cone beam CT radiographs showed multiple types of alveolar and palatal bone morphology, and focused on special types described in the method of Kita et al. It was most frequently found that bone defects in the alveolar crest showed similar patterns in both buccal and palatal aspect, and the buccal bone defect in the nasal floor was larger than the palatal bone defect in the nasal floor. In 80% of the patients, the palatal bone defect showed similar patterns in both anterior and posterior aspects, and the anterior palatal bone defect was smaller than the posterior palatal bone defect. In addition, inadequate bone bridges were frequently found at the cleft site. It is suggested that patients with unilateral cleft lip and palate have various types of alveolar and palatal bone morphology, and are required to take three-dimensional radiographic X-rays prior to any orthodontic treatment. (author)

  2. Visibility of microcalcification in cone beam breast CT − Effects of x-ray tube voltage and radiation dose

    Science.gov (United States)

    Lai, Chao-Jen; Shaw, Chris C.; Chen, Lingyun; Altunbas, Mustafa C.; Liu, Xinming; Han, Tao; Wang, Tianpeng; Yang, Wei T.; Whitman, Gary J.; Tu, Shu-Ju

    2010-01-01

    Mammography is the only technique currently used for detecting microcalcification (MC) clusters, an early indicator of breast cancer. However, mammographic images superimpose a three-dimensional compressed breast image onto two-dimensional projection views, resulting in overlapped anatomical breast structures that may obscure the detection and visualization of MCs. One possible solution to this problem is the use of cone beam computed tomography (CBCT) with a flat-panel (FP) digital detector. Although feasibility studies of CBCT techniques for breast imaging have yielded promising results, they have not shown how radiation dose and x-ray tube voltage affect the accuracy with which MCs are detected by CBCT experimentally. We therefore conducted a phantom study using FP-based CBCT system with various mean glandular doses and kVp values. An experimental CBCT scanner was constructed with a data-acquisition rate of 7.5 frames/s. 10.5- and 14.5cm-diameter breast phantoms made of gelatin were used to simulate uncompressed breasts consisting of 100% glandular tissue. Eight different MC sizes of calcium carbonate grains, ranging from 180–200 µm to 355–425 µm, were used to simulate MCs. MCs of the same size were arranged to form a 5×5 MC cluster and embedded in the breast phantoms. These MC clusters were positioned at 2.8 cm away from the center of the breast phantoms. The phantoms were imaged at 60, 80, and 100 kVp. With a single scan (360 degrees), 300 projection images were acquired with 0.5×, 1×, and 2× mean glandular dose limit for 10.5-cm phantom and with 1×, 2×, and 4× for 14.5-cm phantom. Feldkamp algorithm with a pure ramp filter was used for image reconstruction. The normalized noise level was calculated for each x-ray tube voltage and dose level. The image quality of CBCT images was evaluated by counting the number of visible MCs for each MC cluster for various conditions. The average percentage of the visible MCs were computed and plotted as a

  3. X-ray beam-shaping via deformable mirrors: surface profile and point spread function computation for Gaussian beams using physical optics.

    Science.gov (United States)

    Spiga, D

    2018-01-01

    X-ray mirrors with high focusing performances are commonly used in different sectors of science, such as X-ray astronomy, medical imaging and synchrotron/free-electron laser beamlines. While deformations of the mirror profile may cause degradation of the focus sharpness, a deliberate deformation of the mirror can be made to endow the focus with a desired size and distribution, via piezo actuators. The resulting profile can be characterized with suitable metrology tools and correlated with the expected optical quality via a wavefront propagation code or, sometimes, predicted using geometric optics. In the latter case and for the special class of profile deformations with monotonically increasing derivative, i.e. concave upwards, the point spread function (PSF) can even be predicted analytically. Moreover, under these assumptions, the relation can also be reversed: from the desired PSF the required profile deformation can be computed analytically, avoiding the use of trial-and-error search codes. However, the computation has been so far limited to geometric optics, which entailed some limitations: for example, mirror diffraction effects and the size of the coherent X-ray source were not considered. In this paper, the beam-shaping formalism in the framework of physical optics is reviewed, in the limit of small light wavelengths and in the case of Gaussian intensity wavefronts. Some examples of shaped profiles are also shown, aiming at turning a Gaussian intensity distribution into a top-hat one, and checks of the shaping performances computing the at-wavelength PSF by means of the WISE code are made.

  4. Dental X-ray apparatus

    International Nuclear Information System (INIS)

    Weiss, M.E.

    1980-01-01

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

  5. Detection of short range order in SiO{sub 2} thin-films by grazing-incidence wide and small-angle X-ray scattering

    Energy Technology Data Exchange (ETDEWEB)

    Nagata, Kohki, E-mail: nagata.koki@iri-tokyo.jp [Tokyo Metropolitan Industrial Technology Research Institute, 2-4-10 Aomi, Koto-ku, Tokyo 135-0064 (Japan); School of Science and Technology, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki, Kanagawa 214-8571 (Japan); Ogura, Atsushi [School of Science and Technology, Meiji University, 1-1-1 Higashimita, Tama-ku, Kawasaki, Kanagawa 214-8571 (Japan); Hirosawa, Ichiro [Japan Synchrotron Radiation Research Institute (JASRI), 1-1-1, Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Suwa, Tomoyuki; Teramoto, Akinobu; Ohmi, Tadahiro [New Industry Creation Hatchery Center, Tohoku University, 6-6-10 Aramakiazaaoba, Aoba-ku, Sendai, Miyagi 980-8579 (Japan)

    2016-04-21

    The effects of the fabrication process conditions on the microstructure of silicon dioxide thin films of <10 nm thickness are presented. The microstructure was investigated using grazing-incidence wide and small-angle X-ray scattering methods with synchrotron radiation. The combination of a high brilliance light source and grazing incident configuration enabled the observation of very weak diffuse X-ray scattering from SiO{sub 2} thin films. The results revealed different microstructures, which were dependent on oxidizing species or temperature. The micro-level properties differed from bulk properties reported in the previous literature. It was indicated that these differences originate from inner stress. The detailed structure in an amorphous thin film was not revealed owing to detection difficulties.

  6. Crystalline self-assembly of organic molecules with metal ions at the air-aqueous solution interface. A grazing incidence X-ray scattering study

    DEFF Research Database (Denmark)

    Weissbuch, I.; Buller, R.; Kjær, K.

    2002-01-01

    The advent of intense X-rays from synchrotron sources made possible to probe, at the molecular level, the structural aspects of self-assemblies generated at interfaces. Here we present the two-dimensional (2-D) packing arrangements of two-, three- and multi-component organo-metallic self-assembli......The advent of intense X-rays from synchrotron sources made possible to probe, at the molecular level, the structural aspects of self-assemblies generated at interfaces. Here we present the two-dimensional (2-D) packing arrangements of two-, three- and multi-component organo-metallic self......-assemblies formed via interfacial reaction at the air-aqueous solution interface, as determined by grazing incidence X-ray diffraction (GIRD) and X-ray specular reflectivity techniques. GIXD yields structural information on the crystalline part of the Langmuir film, including the ions and counterions lateral order...... of metal ions bound to the polar head groups of amphipilic molecules; use of bolaamphiphiles to generate oriented thin films with metal ions arranged in periodic layers; delineation of differences in the lateral organization of metal ions at interfaces as induced by racemates and enantiomerically pure...

  7. Characterization of surface Ag nanoparticles in nanocomposite a-C:Ag coatings by grazing incidence X-ray diffraction at sub-critical angles of incidence

    Energy Technology Data Exchange (ETDEWEB)

    Manninen, N.K.; Oliveira, J.C.; Cavaleiro, A. [University of Coimbra, SEG-CEMUC, Mechanical Engineering Department, Coimbra (Portugal); Carvalho, S. [University of Minho, GRF-CFUM, Physics Department, Guimaraes (Portugal)

    2016-03-15

    Silver diffusion within nanocomposite films and/or toward the film surface is often observed during annealing of the silver-based nanocomposite films. In order to control and/or minimize this process, it is crucial to characterize the aggregated silver nanoparticles on the films surface. In this paper grazing incidence X-ray diffraction (GIXRD) with both sub-critical and supra-critical angles of incidence is used to characterize the Ag nanoparticles distribution, shape and structure both inside the matrix and on the nanocomposite film surface. The nanocomposite carbon coating containing Ag nanoparticles (a-C:Ag) was deposited by dc magnetron sputtering. The coatings were analyzed by GIXRD using fixed incident angles both below and above the critical angle for total reflection. By using sub-critical angles it was possible to eliminate diffraction from the bulk material allowing to estimate the size distribution of the nanoparticles sitting on the surface. The results obtained by GIXRD analysis were checked through comparison with the observations made by both TEM and SEM analysis. The proposed methodology can be used to characterized nanoparticles deposition on a surface and/or island formation during film growth as long an adequate substrate with high critical angle for total reflection is used. (orig.)

  8. Stabilized x-ray generator power supply

    International Nuclear Information System (INIS)

    Saha, Subimal; Purushotham, K.V.; Bose, S.K.

    1986-01-01

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

  9. X-ray radiography for container inspection

    Science.gov (United States)

    Katz, Jonathan I [Clayton, MO; Morris, Christopher L [Los Alamos, NM

    2011-06-07

    Arrangements of X-ray inspection systems are described for inspecting high-z materials in voluminous objects such as containers. Inspection methods may involve generating a radiographic image based on detected attenuation corresponding to a pulsed beams of radiation transmitted through a voluminous object. The pulsed beams of radiation are generated by a high-energy source and transmitted substantially downward along an incident angle, of approximately 1.degree. to 30.degree., to a vertical axis extending through the voluminous object. The generated radiographic image may be analyzed to detect on localized high attenuation representative of high-z materials and to discriminate high-z materials from lower and intermediate-z materials on the basis of the high density and greater attenuation of high-z material for higher energy (3-10 MeV) X-rays, and the compact nature of threatening masses of fissionable materials.

  10. High Energy Laboratory Astrophysics using an X-Ray Microcalorimeter with an Electron Beam Ion Trap Project

    Data.gov (United States)

    National Aeronautics and Space Administration — "Since the summer of 2000 we have successfully deployed a high resolution x-ray microcalorimeter spectrometer, based on the spaceflight XRS instrument, at the...

  11. On the properties of synchrotron-like X-ray emission from laser wakefield accelerated electron beams

    Science.gov (United States)

    McGuffey, C.; Schumaker, W.; Matsuoka, T.; Chvykov, V.; Dollar, F.; Kalintchenko, G.; Kneip, S.; Najmudin, Z.; Mangles, S. P. D.; Vargas, M.; Yanovsky, V.; Maksimchuk, A.; Thomas, A. G. R.; Krushelnick, K.

    2018-04-01

    The electric and magnetic fields responsible for electron acceleration in a Laser Wakefield Accelerator (LWFA) also cause electrons to radiate x-ray photons. Such x-ray pulses have several desirable properties including short duration and being well collimated with tunable high energy. We measure the scaling of this x-ray source experimentally up to laser powers greater than 100 TW. An increase in laser power allows electron trapping at a lower density as well as with an increased trapped charge. These effects resulted in an x-ray fluence that was measured to increase non-linearly with laser power. The fluence of x-rays was also compared with that produced from K-α emission resulting from a solid target interaction for the same energy laser pulse. The flux was shown to be comparable, but the LWFA x-rays had a significantly smaller source size. This indicates that such a source may be useful as a backlighter for probing high energy density plasmas with ultrafast temporal resolution.

  12. Portable X-ray reflectometer using a low power polychromatic X-ray tube

    International Nuclear Information System (INIS)

    Ohnishi, Tsunemasa; Imashuku, Susumu; Yuge, Koretaka; Kawai, Jun; Shimura, Naomi

    2014-01-01

    We developed a portable X-ray reflectometer which measures energy dispersive X-ray reflectivity using a polychromatic X-rays from a low power (a few watts) X-ray tube and a silicon drift detector. A thin Cu film on silicon substrate using the portable reflectometer was measured. A fringe pattern was shifted due to the change of the X-ray incident angle. The measured peak position of the fringe pattern was satisfactorily agreed with the calculation. (author)

  13. X-ray based extensometry

    Science.gov (United States)

    Jordan, E. H.; Pease, D. M.

    1988-01-01

    A totally new method of extensometry using an X-ray beam was proposed. The intent of the method is to provide a non-contacting technique that is immune to problems associated with density variations in gaseous environments that plague optical methods. X-rays are virtually unrefractable even by solids. The new method utilizes X-ray induced X-ray fluorescence or X-ray induced optical fluorescence of targets that have melting temperatures of over 3000 F. Many different variations of the basic approaches are possible. In the year completed, preliminary experiments were completed which strongly suggest that the method is feasible. The X-ray induced optical fluorescence method appears to be limited to temperatures below roughly 1600 F because of the overwhelming thermal optical radiation. The X-ray induced X-ray fluorescence scheme appears feasible up to very high temperatures. In this system there will be an unknown tradeoff between frequency response, cost, and accuracy. The exact tradeoff can only be estimated. It appears that for thermomechanical tests with cycle times on the order of minutes a very reasonable system may be feasible. The intended applications involve very high temperatures in both materials testing and monitoring component testing. Gas turbine engines, rocket engines, and hypersonic vehicles (NASP) all involve measurement needs that could partially be met by the proposed technology.

  14. Dental X-ray apparatus

    International Nuclear Information System (INIS)

    Weiss, M.E.

    1980-01-01

    Intra-oral dental X-ray apparatus for panoramic radiography is described in detail. It comprises a tubular target carrier supporting at its distal end a target with an inclined forward face. Image definition is improved by positioning in the path of the X-rays a window of X-ray transmitting ceramic material, e.g. 90% oxide of Be, or Al, 7% Si0 2 . The target carrier forms a probe which can be positioned in the patient's mouth. X-rays are directed forwardly and laterally of the target to an X-ray film positioned externally. The probe is provided with a detachable sleeve having V-form arms of X-ray opaque material which serve to depress the tongue out of the radiation path and also shield the roof of the mouth and other regions of the head from the X-ray pattern. A cylindrical lead shield defines the X-ray beam angle. (author)

  15. X-ray imaging system

    International Nuclear Information System (INIS)

    Houston, J.M.

    1980-01-01

    A novel, high-speed apparatus for use in X-ray computerised tomography is described in detail. It consists of a semi-circular array of X-ray sources, collimators and an ion chamber array for detection of the X-rays. The X-ray sources may be pulsed in salvos such that the corresponding detectors in the array are only illuminated by one source. The use of computer controlled salvos speeds up the image processing by at least a factor of two. The ion chamber array is designed to have a constant detection efficiency for varying angles of X-ray incidence. A detailed description of the detector construction and suggested gaseous fillings are given. It is claimed that the present tomographic system allows fast and accurate imaging of internal body organs and is insensitive to the blurring effects which motion of these organs tends to produce. (UK)

  16. 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:...

  17. Interest of the grazing X ray diffraction to study the evolution of materials under irradiation: behaviour of zirconia under irradiation; Utilisation de la diffraction des rayons X en incidence rasante pour l'etude des solides irradies: application a la zircone

    Energy Technology Data Exchange (ETDEWEB)

    Simeone, D.; Gosset, D.; Bechade, J.L. [CEA Saclay, Dept. des Materiaux pour le Nucleaire DMN, 91 - Gif-sur-Yvette (France)

    2001-07-01

    This document was written to show that grazing X ray diffraction may be a powerful tool to study irradiation damages induced by ion beams in materials. Taking advantage of an asymmetric geometry and a curved detector, it is possible to analyse accurately diffraction diagrams at low angles by taking into account the specific effects induced by the grazing incidence. The interest of grazing incidence is to control the penetration depth of X rays. Such possibility allows to separate effects induced by damages (displacement cascades) and the implantation peak (elastic deformation of the lattice due to the insertion of projectile ions in the matrix). A Rietveld analysis on grazing X ray diagrams shows clearly that displacement cascades induce a phase transition on irradiated zirconia. (authors)

  18. A soft x-ray free electron laser (FEL) using a two-beam elliptical pill-box wake-field cavity

    International Nuclear Information System (INIS)

    Kim, S.H.; Chen, K.W.

    1988-01-01

    Stimulated bremsstrahlung in an undulating electric field in the lasing beam direction (electric wiggler) was shown to be possible from the quantum- mechanical viewpoint. Herein, this possibility is scrutinized from the viewpoint of classical electrodynamics. It is found that if stimulated bremsstrahlung in a transverse undulating magnetic field (magnetic wiggler) occurs, stimulated bremsstrahlung in the electric wiggler must also occur. We further show that a free electron laser (FEL) using a magnetic wiggler to provide a catalyzer field for stimulated bremsstrahlung cannot serve as a practical FEL operating in the soft x-ray region from both theoretical and experimental viewpoints. On the other hand, the authors demonstrate that the FEL using a traveling wake field in a two-beam elliptical pill-box cavity is well suited as a source of coherent radiation in the soft x-ray region

  19. Optical cone beam tomography of Cherenkov-mediated signals for fast 3D dosimetry of x-ray photon beams in water.

    Science.gov (United States)

    Glaser, Adam K; Andreozzi, Jacqueline M; Zhang, Rongxiao; Pogue, Brian W; Gladstone, David J

    2015-07-01

    To test the use of a three-dimensional (3D) optical cone beam computed tomography reconstruction algorithm, for estimation of the imparted 3D dose distribution from megavoltage photon beams in a water tank for quality assurance, by imaging the induced Cherenkov-excited fluorescence (CEF). An intensified charge-coupled device coupled to a standard nontelecentric camera lens was used to tomographically acquire two-dimensional (2D) projection images of CEF from a complex multileaf collimator (MLC) shaped 6 MV linear accelerator x-ray photon beam operating at a dose rate of 600 MU/min. The resulting projections were used to reconstruct the 3D CEF light distribution, a potential surrogate of imparted dose, using a Feldkamp-Davis-Kress cone beam back reconstruction algorithm. Finally, the reconstructed light distributions were compared to the expected dose values from one-dimensional diode scans, 2D film measurements, and the 3D distribution generated from the clinical Varian ECLIPSE treatment planning system using a gamma index analysis. A Monte Carlo derived correction was applied to the Cherenkov reconstructions to account for beam hardening artifacts. 3D light volumes were successfully reconstructed over a 400 × 400 × 350 mm(3) volume at a resolution of 1 mm. The Cherenkov reconstructions showed agreement with all comparative methods and were also able to recover both inter- and intra-MLC leaf leakage. Based upon a 3%/3 mm criterion, the experimental Cherenkov light measurements showed an 83%-99% pass fraction depending on the chosen threshold dose. The results from this study demonstrate the use of optical cone beam computed tomography using CEF for the profiling of the imparted dose distribution from large area megavoltage photon beams in water.

  20. Cosmic x ray physics

    Science.gov (United States)

    Mccammon, Dan; Cox, D. P.; Kraushaar, W. L.; Sanders, W. T.

    1991-01-01

    The annual progress report on Cosmic X Ray Physics for the period 1 Jan. to 31 Dec. 1990 is presented. Topics studied include: soft x ray background, new sounding rocket payload: x ray calorimeter, and theoretical studies.

  1. X-Ray

    Science.gov (United States)

    ... enema. What you can expect During the X-ray X-rays are performed at doctors' offices, dentists' offices, ... as those using a contrast medium. Your child's X-ray Restraints or other techniques may be used to ...

  2. Chest x-ray

    Science.gov (United States)

    Chest radiography; Serial chest x-ray; X-ray - chest ... There is low radiation exposure. X-rays are monitored and regulated to provide the minimum amount of radiation exposure needed to produce the image. Most ...

  3. Abdominal x-ray

    Science.gov (United States)

    Abdominal film; X-ray - abdomen; Flat plate; KUB x-ray ... There is low radiation exposure. X-rays are monitored and regulated to provide the minimum amount of radiation exposure needed to produce the image. Most ...

  4. Quantitative determination of lateral concentration and depth profile of histidine-tagged recombinant proteins probed by grazing incidence X-ray fluorescence.

    Science.gov (United States)

    Körner, Alexander; Abuillan, Wasim; Deichmann, Christina; Rossetti, Fernanda F; Köhler, Almut; Konovalov, Oleg V; Wedlich, Doris; Tanaka, Motomu

    2013-05-02

    We have demonstrated that the complementary combination of grazing incidence X-ray fluorescence (GIXF) with specular X-ray reflectivity (XRR) can be used to quantitatively determine the density profiles of Ni(2)(+) ions complexed with chelator headgroups as well as S atoms in recombinant proteins anchored to lipid monolayers at the air/water interface. First, we prepared phospholipid monolayers incorporating chelator lipid anchors at different molar fractions at the air/water interface. The fine-structures perpendicular to the global plane of monolayers were characterized by XRR in the presence of Ni(2)(+) ions, yielding the thickness, roughness, and electron density of the stratified lipid monolayers. X-ray fluorescence intensities from Ni Kα core levels recorded at the incidence angles below and above the critical angle of total reflection allow for the determination of the position and lateral density of Ni(2)(+) ions associated with chelator headgroups with a high spatial accuracy (±5 Å). The coupling of histidine-tagged Xenopus cadherin 11 (Xcad-11) can also be identified by changes in the fines-structures using XRR. Although fluorescence intensities from S Kα level were much weaker than Ni Kα signals, we could detect the location of S atoms in recombinant Xcad-11 proteins.

  5. 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.

  6. Diffracted beam-transmitted beam Borrmann X-ray topography in copper. A novel method of stereo depth topography

    International Nuclear Information System (INIS)

    Hamill, G.P.; Vreeland, T. Jr.

    1979-01-01

    The observed depths of dislocations, as measured from the exit surface of a copper single crystal, are within a region of the crystal where μd, the kinematic linear absorption coefficient times the depth, is less than or approximately equal to unity. Splitting of the Borrmann wave into its diffracted and transmitted beam components is indicated in relatively perfect portions of the crystal near the exit surface. (Auth.)

  7. X-ray astronomy

    International Nuclear Information System (INIS)

    Giacconi, R.; Gursky, H.

    1974-01-01

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

  8. Assessment of flatness and symmetry of megavoltage x-ray beam with an electronic portal imaging device

    CERN Document Server

    Liu, G; Bezak, E

    2002-01-01

    The input/output characteristics of the Wellhofer BIS 710 electronic portal imaging device (EPID) have been investigated to establish its efficacy for periodic quality assurance (QA) applications. Calibration curves have been determined for the energy fluence incident on the detector versus the pixel values. The effect of the charge coupled device (CCD) camera sampling time and beam parameters (such as beam field size, dose rate, photon energy) on the calibration have been investigated for a region of interest (ROI) around the central beam axis. The results demonstrate that the pixel output is a linear function of the incident exposure, as expected for a video-based electronic portal imaging system. The field size effects of the BIS 710 are similar to that of an ion chamber for smaller field sizes up to 10 x 10 cm sup 2. However, for larger field sizes the pixel value increases more rapidly. Furthermore, the system is slightly sensitive to dose rate and is also energy dependent. The BIS 710 has been used in t...

  9. Study of molecule-metal interfaces by means of the normal incidence X-ray standing wave technique

    International Nuclear Information System (INIS)

    Mercurio, Giuseppe

    2012-01-01

    Functional surfaces based on monolayers of organic molecules are currently subject of an intense research effort due to their applications in molecular electronics, sensing and catalysis. Because of the strong dependence of organic based devices on the local properties of the molecule-metal interface, a direct investigation of the interface chemistry is of paramount importance. In this context, the bonding distance, measured by means of the normal incidence X-ray standing wave technique (NIXSW), provides a direct access to the molecule-metal interactions. At the same time, NIXSW adsorption heights are used to benchmark different density functional theory (DFT) schemes and determine the ones with predictive power for similar systems. This work investigates the geometric and chemical properties of different molecule/metal interfaces, relevant to molecular electronics and functional surfaces applications, primarily by means of the NIXSW technique. All NIXSW data are analyzed with the newly developed open source program Torricelli, which is thoroughly documented in the thesis. In order to elucidate the role played by the substrate within molecule/metal interfaces, the prototype organic molecule 3,4,9,10-perylene-tetracarboxylic-dianhydride (PTCDA) is explored on the Ag(110) surface. The molecule results more distorted and at smaller bonding distances on the more reactive Ag(110) surface, in comparison with the Ag(100), the Ag(111) and Au(111) substrates. This conclusion follows from the detailed molecular adsorption geometry obtained from the differential analysis of nonequivalent carbon and oxygen species (including a careful error analysis). Subsequently, the chemisorptive PTCDA/Ag(110) interaction is tuned by the co-deposition of an external alkali metal, namely K. As a consequence, the functional groups of PTCDA unbind from the surface, which, in turn, undergoes major reconstruction. In fact, the resulting nanopatterned surface consists of alternated up and down

  10. A microbeam grazing-incidence approach to L-shell x-ray fluorescence measurements of lead concentration in bone and soft tissue phantoms.

    Science.gov (United States)

    Gherase, Mihai Raul; Al-Hamdani, Summer

    2018-02-06

    L-shell x-ray fluorescence (LXRF) is a non-invasive approach to lead (Pb) concentration measurements in the human bone. The first studies were published in the early 1980s. In the same period the K-shell x-ray fluorescence (KXRF) method using a Cd-109 radionuclide source was developed and later improved and refined. Lower sensitivity and calibration difficulties associated with the LXRF method led the KXRF to be the most adopted method for in vivo human bone Pb studies. In the present study a microbeam-based grazing-incidence approach to Pb LXRF measurements was investigated. The microbeam produced by an integrated x-ray tube and polycapillary x-ray lens (PXL) unit was used to excite cylindrical plaster-of-Paris (poP) bone phantoms doped with Pb in seven concentrations: 0, 8, 16, 26, 34, 59, and 74 µg/g. Two 1 mm- and 3 mm-thick cylindrical shell soft tissue phantoms were made out of polyoxymethylene (POM) plastic. Three bone-soft tissue phantom sets corresponding to the 0, 1, and 3 mm POM thickness values resulted. Each phantom was placed between the microbeam and the detector; its position was controlled using a positioning stage. Small steps (0.1-0.5 mm) and short 30 s x-ray spectra acquisitions were used to find the optimal phantom position according to the maximum observed Sr Kα peak height. At the optimal geometry, five 180 s x-ray spectra were acquired for each phantom set. Calibration lines were obtained using the fitted peak heights of the two observed Pb Lα and Pb Lβ peaks. The lowest detection limit (DL) values were (2.9±0.2), (4.9±0.3), and (23±3) µg/g, respectively. The order of magnitude of the absorbed radiation dose in the POM plastic for the 180 s irradiation was estimated to be <1 mGy. The results are superior to a relatively recently-published LXRF phantom study and show promise for future designs of in vivo LXRF measurements. Creative Commons Attribution license.

  11. Beam tracking approach for single–shot retrieval of absorption, refraction, and dark-field signals with laboratory  x-ray sources

    International Nuclear Information System (INIS)

    Vittoria, Fabio A.; Diemoz, Paul C.; Olivo, Alessandro; Kallon, Gibril K. N.; Basta, Dario; Endrizzi, Marco; Robinson, Ian K.

    2015-01-01

    We present the translation of the beam tracking approach for x-ray phase-contrast and dark-field imaging, recently demonstrated using synchrotron radiation, to a laboratory setup. A single absorbing mask is used before the sample, and a local Gaussian interpolation of the beam at the detector is used to extract absorption, refraction, and dark–field signals from a single exposure of the sample. Multiple exposures can be acquired when high resolution is needed, as shown here. A theoretical analysis of the effect of polychromaticity on the retrieved signals, and of the artifacts this might cause when existing retrieval methods are used, is also discussed

  12. Beam tracking approach for single–shot retrieval of absorption, refraction, and dark-field signals with laboratory  x-ray sources

    Energy Technology Data Exchange (ETDEWEB)

    Vittoria, Fabio A., E-mail: fabio.vittoria.12@ucl.ac.uk; Diemoz, Paul C.; Olivo, Alessandro [Department of Medical Physics and Biomedical Engineering, University College London, Malet Place, Gower Street, London WC1E 6BT (United Kingdom); Research Complex at Harwell, Harwell Oxford Campus, OX11 0FA Didcot (United Kingdom); Kallon, Gibril K. N.; Basta, Dario; Endrizzi, Marco [Department of Medical Physics and Biomedical Engineering, University College London, Malet Place, Gower Street, London WC1E 6BT (United Kingdom); Robinson, Ian K. [Research Complex at Harwell, Harwell Oxford Campus, OX11 0FA Didcot (United Kingdom); London Centre for Nanotechnology, WC1H 0AH London (United Kingdom)

    2015-06-01

    We present the translation of the beam tracking approach for x-ray phase-contrast and dark-field imaging, recently demonstrated using synchrotron radiation, to a laboratory setup. A single absorbing mask is used before the sample, and a local Gaussian interpolation of the beam at the detector is used to extract absorption, refraction, and dark–field signals from a single exposure of the sample. Multiple exposures can be acquired when high resolution is needed, as shown here. A theoretical analysis of the effect of polychromaticity on the retrieved signals, and of the artifacts this might cause when existing retrieval methods are used, is also discussed.

  13. A Measurement Method for HVL Estimation of X-ray Spectrum Output

    International Nuclear Information System (INIS)

    Suric, M.; Radalj, Z.; Prlic, I.; Vrtar, M.

    2003-01-01

    While performing diagnostic radiology procedures stability and constancy of X-ray anode voltage are very important. Variations in kVp value changes X-ray beam's intensity and its penetrating power. Filters are commonly used in diagnostic radiology techniques to minimize a dose received by a patient without decreasing desired contrast of the diagnostic image. HVL (Half Value Layer) is used as a measurable quality parameter for X-ray beams and it is defined as a value of absorber thickness, which will transmit one half of the incident intensity of the X-ray radiation output incident upon it. It is known that HVL depends proportionally on kVp value so detecting any changes in HVL for the same nominal X-ray tube kVp value will indicate the malfunctions of the X-ray generator. In this paper a simple method of HVL determination using set of aluminum step wedges is presented. The method enables very simple and precise HVL determination and it is capable of detecting variations in kVp value, which are less than 5% of the nominal value. Using this method while performing periodical testing of X-ray units with constant parameters (chosen kVp and mAs value) could provide frequent kVp value monitoring, determining HVL changes, and controlling the beam intensity comparing X-ray films blackening from images taken with the same nominal parameters. (author)

  14. Investigation of thickness dependent composition of boron carbide thin films by resonant soft x-ray reflectivity

    OpenAIRE

    Rao, P. N.; Gupta, R. K.; Saravanan, K.; Bose, A.; Joshi, S. C.; Ganguli, T.; Rai, S. K.

    2017-01-01

    Boron carbide thin films of different thicknesses deposited by ion beam sputtering were studied. The deposited films were characterized by grazing incidence hard x-ray reflectivity (GIXR), resonant soft x-ray reflectivity (RSXR), x-ray photo electron spectroscopy (XPS), resonant Rutherford backscattering spectrometry (RRBS), and time of flight secondary ion mass spectrometry (TOF-SIMS). An in-depth profile of the chemical elements constitute the films is reconstructed based on analysis of ref...

  15. Generation and application of soft-X-ray by means of inverse compton scattering between high quality election beam and IR laser

    International Nuclear Information System (INIS)

    Washio, M.; Sakaue, K.; Hama, Y.; Kamiya, Y.; Moriyama, R.; Hezume, K.; Saito, T.; Kuroda, R.; Kashiwagi, S.; Ushida, K.; Hayano, H.; Urakawa, J.

    2006-01-01

    High quality beam generation project based on High-Tech Research Center Project, which has been approved by Ministry of Education, Culture, Sports, Science and Technology in 1999, has been conducted by advance research institute for science and engineering, Waseda University. In the project, laser photo-cathode RF-gun has been selected for the high quality electron beam source. RF cavities with low dark current, which were made by diamond turning technique, have been successfully manufactured. The low emittance electron beam was realized by choosing the modified laser injection technique. The obtained normalized emittance was about 3 mm·mrad at 100 pC of electron charge. The soft X-ray beam generation with the energy of 370 eV, which is in the energy region of so-called 'water window', by inverse Compton scattering has been performed by the collision between IR laser and the low emittance electron beams. (authors)

  16. Comparative feasibility of gamma, electron beam and x-rays facilities at the Kuala Lumpur International airport (KLIA), Sepang, Malaysia

    International Nuclear Information System (INIS)

    Muhamad Lebai Juri; Sidek Othman; Wan Mashol Wan Zain; Ridzuan Ismail

    1997-01-01

    Malaysia is one of the world's leading producers of rubber, palm oil and cocoa beans. There is a great concern within the commodity industries of the possible outbreak of plant diseases yet to be detected in the country but endemic in the South American tropics and Africa. The risk of transferring the diseases to Malaysia are high because of increasing contacts between Malaysia and the South American countries and Africa through trades, tourism and the South-South cooperation. Diseases of particular importance are the South American leaf blight (SALB) of rubber, vascular wilts of oil palm and witches'broom of cocoa caused by Microcyclus ulei, Fusarium oxysporum f sp. elaeidies and Crinipellis pemiciosa (Stahel) Singer respectively. Recent estimates by the Agriculture Department of Malaysia indicated in the event of large scale attack by SALB on rubber would result in revenue loss of a staggering RM 3-3.5 billion per annum, an equivalent of 70% loss in rubber acreage. This excludes massive unemployment in the rubber industry and cost of cleaning up activities to eradicate and free plantations of SALB. Recurring attacks of the diseases cannot be discounted given the fact that spores of fungi can remain dormant for years but still viable. Stringent control and quarantine steps are presently being exercised by the authorities to intercept at airports and hence prevent entry of infectious plant diseases in Malaysia. Many of the measures using chemicals, ultra violet light (UV), steam sterilization, air blowers etc. are not sufficiently effective in killing fungi especially when spores are carried in the personal belongings of air-passengers. There was suggestion that ionizing radiation offers alternative to the present methods for intercepting pathogens at the port of entry. This paper will firstly, discuss results on the investigations carried out to compare the effectiveness of various ionizing radiation sources, i.e., gamma, electron beam and x-rays; chemicals and UV

  17. Comparison of vessel contrast measured with a scanning-beam digital x-ray system and an image intensifier/television system

    International Nuclear Information System (INIS)

    Speidel, Michael A.; Wilfley, Brian P.; Heanue, Joseph A.; Betts, Timothy D.; Van Lysel, Michael S.

    2001-01-01

    Vessel contrast was measured in the fluoroscopic images produced by a scanning-beam digital x-ray (SBDX) system and an image intensifier/television (II/TV) based system. The SBDX system electronically scans a series of pencil x-ray beams across the patient, each of which is directed at a distant small-area detector array. The reduction in detected scatter achieved with this geometry was expected to provide an increase in image contrast. Vessel contrast was evaluated from images of a phantom containing iodinated tubes. The vessels were inserted into an acrylic stack to provide a patient-mimicking scattering medium. Vessel diameter ranged from 0.3 to 3.1 mm. Images were acquired at 100 kVp with the SBDX and II/TV systems and averaged to reduce x-ray noise. The II/TV system was operated in the 6-in. image intensifier mode with an anti-scatter grid. The increase in contrast in the SBDX images, expressed as a ratio of the measured SBDX and II/TV contrasts, ranged from 1.63 to 1.79 for individual vessels. This agreed well with a prediction of the contrast improvement ratio for this experiment, based on measurements of the scatter fraction, object-plane line spread functions, and consideration of the source spectrum and detector absorption properties. The predicted contrast improvement ratio for SBDX relative to II/TV images was 1.62 to 1.77

  18. Studying signal collection in the punch-through protection area of a silicon micro-strip sensor using a micro-focused X-ray beam

    CERN Document Server

    Poley, Anne-luise; The ATLAS collaboration

    2018-01-01

    For the Phase-II Upgrade of the ATLAS detector, a new, all-silicon tracker will be constructed in order to cope with the increased track density and radiation level of the High-Luminosity Large Hadron Collider. While silicon strip sensors are designed to minimise the fraction of dead material and maximise the active area of a sensor, concessions must be made to the requirements of operating a sensor in a particle physics detector. Sensor geometry features like the punch-through protection deviate from the standard sensor architecture and thereby affect the charge collection in that area. In order to study the signal collection of silicon strip sensors over their punch-through-protection area, ATLAS silicon strip sensors were scanned with a micro-focused X-ray beam at the Diamond Light Source. Due to the highly focused X-ray beam ($\\unit[2\\times3]{\\upmu\\text{m}}^2$) and the short average path length of an electron after interaction with an X-ray photon ($\\unit[\\leq2]{\\upmu\\text{m}}$), local signal collection i...

  19. Grazing incidence diffraction and X-ray reflectivity studies of the interactions of inorganic mercury salts with membrane lipids in Langmuir monolayers at the air/water interface.

    Science.gov (United States)

    Broniatowski, Marcin; Flasiński, Michał; Dynarowicz-Łatka, Patrycja; Majewski, Jarosław

    2010-07-29

    The interactions of mercury ions with the membrane phospholipids are considered to be of great importance regarding the toxicity of this metal in living organisms. To obtain deeper insight into this problem, we performed systematic studies applying the Langmuir technique complemented with synchrotron X-ray scattering methods (grazing incidence X-ray diffraction (GIXD) and X-ray reflectivity (XR)). We focused our attention on the interactions of inorganic mercury salts dissolved in the aqueous subphase with lipid monolayers, formed by selected membrane phospholipids, namely, dipalmitoylphosphatidylglicerol (DPPG), dipalmitoylphosphatidylcholine (DPPC), 1-octadecyl 2-sn-phosphatidylcholine (lyso-PC), and sphingomyelin (SM). Two different inorganic mercury salts, one of a hydracid, HgCl(2), and the other of an oxacid, Hg(NO(3))(2), have been investigated. Our results proved that the elastic properties of phospholipid monolayers are a key factor regarding the interactions with mercury ions. Significant differences in mercury ions complexation are observed with double-chain phospholipids (such as DPPG and DPPC) forming fluid layers of low compressibility and phospholipids forming more compressible films (like SM and lyso-PC). Namely, important changes in the monolayer characteristic were observed only for the latter kind of lipids. This is an important finding taking into account the accumulation of mercury in the central nervous system and its neurotoxic effects. SM is one of the most abundant lipids in neurons shells and therefore can be considered as a target lipid complexing mercury ions.

  20. The value of advanced multiple beam equalization radiography (AMBER) and storage phosphor radiography in chest X-rays

    International Nuclear Information System (INIS)

    Richter, C.S.; Richter, K.; Stein, R.; Busch, H.P.

    1993-01-01

    The study compared the quality of roentgenologic criteria in the evaluation of the heart and pulmonary vessels on chest X-rays obtained with different imaging systems. Fifty patients had four different chest radiographs, i.e. conventional chest X-rays, AMBER images, digital storage phosphor images, and digital storage radiographs that were obtained with the AMBER system. Comparison of techniques was based on 12 well-defined quality criteria of chest X-rays. Four radiologists with expertise reviewed the films according to these criteria. The AMBER technique was found to be superior to the remaining imaging modalities in visualization of the central pulmonary vessels, the descending aorta, and the left atrium. Peripheral pulmonary vessels were best appreciated with AMBER technique combined with storage phosphor technique. The same technique was superior in the assessment of all cardiovascular criteria. The superiority of this technique versus conventional chest X-rays can be explained on the basis of the linear slope of the gradation curve of AMBER and digital techniques. (orig.) [de