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Sample records for 4th generation x-ray

  1. X-ray generator

    DOEpatents

    Dawson, John M.

    1976-01-01

    Apparatus and method 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 striped 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. To this end, the laser spark is produced by injecting a laser light beam, or a plurality of beams, into a first gas in a cylindrical container having an adjacent second gas layer co-axial therewith, the laser producing a plasma and the intense primary x-rays in the first gas, and the second gas containing the high and low atomic number elements for receiving the primary x-rays, whereupon the secondary x-rays are produced therein by stripping desired ions in a neutral gas and transfer of electrons to highly excited states of the stripped ions from the unionized atoms. Means for magnetically confining and stabilizing the plasma are disclosed for controlling the direction of the x-rays.

  2. Electromechanical x-ray generator

    DOEpatents

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

    2016-05-03

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

  3. Electron beam parallel X-ray generator

    NASA Technical Reports Server (NTRS)

    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.

  4. Capillary Optics generate stronger X-rays

    NASA Technical Reports Server (NTRS)

    1996-01-01

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

  5. Next-Generation X-Ray Astronomy

    NASA Astrophysics Data System (ADS)

    White, Nicholas E.

    2012-04-01

    This review of future timing capabilities in X-ray astronomy includes missions in implementation (astro-h, gems, srg and astrosat), those under study (currently nicer, athena and loft), and new technologies that may be the seeds for future missions, such as lobster-eye optics. Those missions and technologies will offer exciting new capabilities that will take X-ray Astronomy into a new generation of achievements.

  6. Flywheel-powered X-ray generator

    NASA Technical Reports Server (NTRS)

    Siedband, M. P.

    1984-01-01

    The use of a small flywheel appears to be a practical alternative to other power sources for mobile X-ray system applications. A 5 kg flywheel has been constructed which runs at 10 krpm and stores 30 KJ while requiring less than 500 W to bring the system up to speed. The wheel is coupled to an aircraft alternator and can yield pulsed power levels over 50 KWp. The aircraft alternator has the advantage of high frequency output which has also permitted the design of smaller high voltage transformers. A series of optical sensors detecting shaft position function as an electronic commutator so that the alternator may operate as a motor to bring the wheel up to operating speed. The system permits the generation of extremely powerful X-rays from a variety of low power sources such as household power outlets, automobile batteries or sources of poorly regulated electrical power such as those found in third world countries.

  7. Next Generation X-ray Polarimeter

    NASA Astrophysics Data System (ADS)

    Hill-Kittle, Joe

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

  8. Pressure Dependence of X-Ray Yield on Cooling for Crystal X-Ray Generator

    NASA Astrophysics Data System (ADS)

    Trott, D. W.; Shafroth, S. M.

    1999-11-01

    The UNC crystal x-ray generator consists of a 6.5 x 3.1 x 2 mm LiTaO3 pyroelectric crystal, whose temperature can range from 22 to 120 degrees Celsius. A SiLi detector, placed approximately 1 cm away from a target, is used to detect x-rays from both the pyroelectric crystal and a thin target of Fe evaporated on to a Cu foil. When one surface of the crystal is heated a strong electric field is produced on the other side which accelerates electrons toward the crystal producing Ta L and M x-rays. During cooling, the electric field reverses and a target x-ray spectrum is obtained. The chamber can be pumped on so that effects of gas pressure can be studied. The x-ray intensity changes with varying pressure. Repeatable measurements have been done using the x-ray generator at various low pressures ranging from 5 to 30 mTorr. At low pressures, the x-ray yield is relatively constant with time. As the pressure increases an initial high x-ray peak is produced which decreases rapidly with time. The most dramatic increase seen in x-ray yield peak occurs between 20 and 30 mTorr differing by 64 counts/sec and 224 counts/sec, respectively.

  9. Apparatus for generating x-ray holograms

    DOEpatents

    Rhodes, Charles K.; Boyer, Keith; Solem, Johndale C.; Haddad, Waleed S.

    1990-01-01

    Apparatus for x-ray microholography of living biological materials. A Fourier transform holographic configuration is described as being most suitable for the 3-dimensional recording of the physical characteristics of biological specimens. The use of a spherical scatterer as a reference and a charge-coupled device two-dimensional detector array placed in the forward direction relative to the incident x-radiation for viewing electromagnetic radiation simultaneously scattered from both the specimen and the reference scatterer permits the ready reconstruction of the details of the specimen from the fringe pattern detected by the charge-coupled device. For example, by using a nickel reference scatter at 4.5 nm, sufficient reference illumination is provided over a wide enough angle to allow similar resolution in both transverse and longitudinal directions. Both laser and synchrotron radiation sources are feasible for generating microholographs. Operation in the water window (2.4 to 4.5 nm) should provide maximum contrast for features of the specimen and spatial resolution on the order of the wavelength of x-radiation should be possible in all three dimensions, which is sufficient for the visualization of many biological features. It is anticipated that the present apparatus will find utility in other areas as well where microscopic physical details of a specimen are important. A computational procedure which enables the holographic data collected by the detector to be used to correct for misalignments introduced by inexact knowledge of the relative positions of the spherical reference scatterer and the sample under investigation has been developed. If the correction is performed prior to reconstruction, full compensation can be achieved and a faithfully reconstructed image produced.

  10. Apparatus for generating x-ray holograms

    DOEpatents

    Rhodes, C.K.; Boyer, K.; Solem, J.C.; Haddad, W.S.

    1990-09-11

    Apparatus for x-ray microholography of living biological materials. A Fourier transform holographic configuration is described as being most suitable for the 3-dimensional recording of the physical characteristics of biological specimens. The use of a spherical scatterer as a reference and a charge-coupled device two-dimensional detector array placed in the forward direction relative to the incident x-radiation for viewing electromagnetic radiation simultaneously scattered from both the specimen and the reference scatterer permits the ready reconstruction of the details of the specimen from the fringe pattern detected by the charge-coupled device. For example, by using a nickel reference scatter at 4.5 nm, sufficient reference illumination is provided over a wide enough angle to allow similar resolution in both transverse and longitudinal directions. Both laser and synchrotron radiation sources are feasible for generating microholographs. Operation in the water window (2.4 to 4.5 nm) should provide maximum contrast for features of the specimen and spatial resolution on the order of the wavelength of x-radiation should be possible in all three dimensions, which is sufficient for the visualization of many biological features. It is anticipated that the present apparatus will find utility in other areas as well where microscopic physical details of a specimen are important. A computational procedure which enables the holographic data collected by the detector to be used to correct for misalignments introduced by inexact knowledge of the relative positions of the spherical reference scatterer and the sample under investigation has been developed. If the correction is performed prior to reconstruction, full compensation can be achieved and a faithfully reconstructed image produced. 7 figs.

  11. Plasma flash x-ray generator (PFXG-02)

    NASA Astrophysics Data System (ADS)

    Sato, Eiichi; Germer, Rudolf K.; Hayasi, Yasuomi; Tanaka, Etsuro; Mori, Hidezo; Kawai, Toshiaki; Usuki, Tatsumi; Sato, Koetsu; Obara, Haruo; Zuguchi, Masayuki; Ichimaru, Toshio; Ojima, Hidenori; Takayama, Kazuyoshi; Ido, Hideaki

    2003-07-01

    In the plasma flash x-ray generator, high-voltage main condenser of about 200 nF is charged up to 50 kV by a power supply, and electric charges in the condenser are discharged to an x-ray tube after triggering the cathode electrode. The flash x-rays are then produced. The x-ray tube is of a demountable triode that is connected to a turbo molecular pump with a pressure of approximately 1 mPa. As electron flows from the cathode electrode are roughly converged to a rod iron target of 3.0 mm in diameter by electric field in the x-ray tube, the weakly ionized linear plasma, which consists of iron ions and electrons, forms by target evaporating. At a charging voltage of 50 kV, the maximum tube voltage was almost equal to the charging voltage of the main condenser, and the peak current was about 20 kA. When the charging voltage was increased, the linear plasma formed, and the K-series characteristic x-ray intensities increased. The x-ray pulse widths were about 800 ns, and the time-integrated x-ray intensity had a value of about 10 μC/kg at 1.0 m from x-ray source with a charging voltage of 50 kV. The plasma x-rays were diffused after passing through two lead slits.

  12. X-ray generation using carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Parmee, Richard J.; Collins, Clare M.; Milne, William I.; Cole, Matthew T.

    2015-01-01

    Since the discovery of X-rays over a century ago the techniques applied to the engineering of X-ray sources have remained relatively unchanged. From the inception of thermionic electron sources, which, due to simplicity of fabrication, remain central to almost all X-ray applications, there have been few fundamental technological advances. However, with the emergence of ever more demanding medical and inspection techniques, including computed tomography and tomosynthesis, security inspection, high throughput manufacturing and radiotherapy, has resulted in a considerable level of interest in the development of new fabrication methods. The use of conventional thermionic sources is limited by their slow temporal response and large physical size. In response, field electron emission has emerged as a promising alternative means of deriving a highly controllable electron beam of a well-defined distribution. When coupled to the burgeoning field of nanomaterials, and in particular, carbon nanotubes, such systems present a unique technological opportunity. This review provides a summary of the current state-of-the-art in carbon nanotube-based field emission X-ray sources. We detail the various fabrication techniques and functional advantages associated with their use, including the ability to produce ever smaller electron beam assembles, shaped cathodes, enhanced temporal stability and emergent fast-switching pulsed sources. We conclude with an overview of some of the commercial progress made towards the realisation of an innovative and disruptive technology.

  13. Multilayers for next generation x-ray sources

    SciTech Connect

    Bajt, S; Chapman, H N; Spiller, E; Hau-Riege, S; Alameda, J; Nelson, A J; Walton, C C; Kjornrattanawanich, B; Aquila, A; Dollar, F; Gullikson, E; Tarrio, C

    2007-05-04

    Multilayers are artificially layered structures that can be used to create optics and optical elements for a broad range of x-ray wavelengths, or can be optimized for other applications. The development of next generation x-ray sources (synchrotrons and x-ray free electron lasers) requires advances in x-ray optics. Newly developed multilayer-based mirrors and optical elements enabled efficient band-pass filtering, focusing and time resolved measurements in recent FLASH (Free Electron LASer in Hamburg) experiments. These experiments are providing invaluable feedback on the response of the multilayer structures to high intensity, short pulsed x-ray sources. This information is crucial to design optics for future x-ray free electron lasers and to benchmark computer codes that simulate damage processes.

  14. Generation of first hard X-ray pulse at Tsinghua Thomson Scattering X-ray Source.

    PubMed

    Du, Yingchao; Yan, Lixin; Hua, Jianfei; Du, Qiang; Zhang, Zhen; Li, Renkai; Qian, Houjun; Huang, Wenhui; Chen, Huaibi; Tang, Chuanxiang

    2013-05-01

    Tsinghua Thomson Scattering X-ray Source (TTX) is the first-of-its-kind dedicated hard X-ray source in China based on the Thomson scattering between a terawatt ultrashort laser and relativistic electron beams. In this paper, we report the experimental generation and characterization of the first hard X-ray pulses (51.7 keV) via head-on collision of an 800 nm laser and 46.7 MeV electron beams. The measured yield is 1.0 × 10(6) per pulse with an electron bunch charge of 200 pC and laser pulse energy of 300 mJ. The angular intensity distribution and energy spectra of the X-ray pulse are measured with an electron-multiplying charge-coupled device using a CsI scintillator and silicon attenuators. These measurements agree well with theoretical and simulation predictions. An imaging test using the X-ray pulse at the TTX is also presented. PMID:23742539

  15. Generation of first hard X-ray pulse at Tsinghua Thomson Scattering X-ray Source

    SciTech Connect

    Du Yingchao; Yan Lixin; Hua Jianfei; Du Qiang; Zhang Zhen; Li Renkai; Qian Houjun; Huang Wenhui; Chen Huaibi; Tang Chuanxiang

    2013-05-15

    Tsinghua Thomson Scattering X-ray Source (TTX) is the first-of-its-kind dedicated hard X-ray source in China based on the Thomson scattering between a terawatt ultrashort laser and relativistic electron beams. In this paper, we report the experimental generation and characterization of the first hard X-ray pulses (51.7 keV) via head-on collision of an 800 nm laser and 46.7 MeV electron beams. The measured yield is 1.0 Multiplication-Sign 10{sup 6} per pulse with an electron bunch charge of 200 pC and laser pulse energy of 300 mJ. The angular intensity distribution and energy spectra of the X-ray pulse are measured with an electron-multiplying charge-coupled device using a CsI scintillator and silicon attenuators. These measurements agree well with theoretical and simulation predictions. An imaging test using the X-ray pulse at the TTX is also presented.

  16. Generation of High Brightness X-rays with the PLEIADES Thomson X-ray Source

    SciTech Connect

    Brown, W J; Anderson, S G; Barty, C P J; Crane, J K; Cross, R R; Fittinghoff, D N; Hartemann, F V; Kuba, J; LeSage, G P; Slaughter, D R; Springer, P T; Tremaine, A M; Rosenzweig, J B; Gibson, D J

    2003-05-28

    The use of short laser pulses to generate high peak intensity, ultra-short x-ray pulses enables exciting new experimental capabilities, such as femtosecond pump-probe experiments used to temporally resolve material structural dynamics on atomic time scales. PLEIADES (Picosecond Laser Electron InterAction for Dynamic Evaluation of Structures) is a next generation Thomson scattering x-ray source being developed at Lawrence Livermore National Laboratory (LLNL). Ultra-fast picosecond x-rays (10-200 keV) are generated by colliding an energetic electron beam (20-100 MeV) with a high intensity, sub-ps, 800 nm laser pulse. The peak brightness of the source is expected to exceed 10{sup 20} photons/s/0.1% bandwidth/mm2/mrad2. Simulations of the electron beam production, transport, and final focus are presented. Electron beam measurements, including emittance and final focus spot size are also presented and compared to simulation results. Measurements of x-ray production are also reported and compared to theoretical calculations.

  17. Next-Generation X-Ray Astronomy

    NASA Technical Reports Server (NTRS)

    White, Nicholas E.

    2011-01-01

    The future timing capabilities in X-ray astronomy will be reviewed. This will include reviewing the missions in implementation: Astro-H, GEMS, SRG, and ASTROSAT; those under study: currently ATHENA and LOFT; and new technologies that may enable future missions e.g. Lobster eye optics. These missions and technologies will bring exciting new capabilities across the entire time spectrum from micro-seconds to years that e.g. will allow us to probe close to the event horizon of black holes and constrain the equation of state of neutron stars.

  18. Generating revenue from X-ray waste.

    PubMed

    Hundal, Simon

    2013-09-01

    According to Betts Envirometal, experts in precious metal recovery from waste streams, and a provider of 'total waste management' solutions, 'disposing of hospital wastes isn't usually a glamorous subject, unless, of course, you know how to make money from it'. As general manager, Simon Hundal, explains, the company is seeking to 'revolutionise' how the NHS treats certain waste streams, and, in doing so, to encourage NHS Trust directors and governance managers to check their compliance with patient data retention guidelines as far as medical X-ray film, in particular, is concerned. PMID:24138001

  19. X-ray-generated ultrasonic signals - Characteristics and imaging applications

    NASA Astrophysics Data System (ADS)

    Sachse, W.; Kim, K. Y.; Pierce, W. F.

    1986-09-01

    Experiments dealing with the characterization of X-ray-generated ultrasonic signals in materials and their application to the imaging of material inhomogeneities are described. A linear relationship is established between the X-ray photon power and the generated ultrasonic signals. The directivity of the X-ray/acoustic source was found to resemble that of other thermoelastic sources. A new double-modulation measurement technique is described in which the magnitude and phase of the modulated acoustic signals are measured. Use of the technique is explored with various materials, incident beam sizes, and inclusions. The results of preliminary imaging experiments are described which were carried out with direct and double-modulated X-ray/acoustic signals. It is shown from these results that using the images generated at two modulation frequencies, identification of the spatial inhomogeneities in a specimen is possible.

  20. Interstellar dust as generator of x ray radiation

    NASA Technical Reports Server (NTRS)

    Ibadov, Subhon

    1989-01-01

    The x ray generation due to arising of hot dense plasma balls at high-velocity (greater than or equal to 70 km/s) collisions of dust grains in the interstellar medium is considered. Analytical expressions for efficiency of conversions of colliding dust particle kinetic energy into x ray radiation are presented. The observed intensity distribution of the diffuse component of soft cosmic x rays (0.1 to 1 keV) may be partly caused by collisions between the dusty components of high velocity clouds and of the disk of the Galaxy.

  1. Prepulse dependence in hard x-ray generation from microdroplets

    SciTech Connect

    Anand, M.; Kahaly, S.; Kumar, G. Ravindra; Sandhu, A. S.; Gibbon, P.; Krishnamurthy, M.

    2006-04-07

    We report on experiments which show that liquid microdroplets are very efficient in hard x-ray generation. We make a comparative study of hard x-ray emission from 15 {mu}m methanol microdroplets and a plain slab target of similar atomic composition at similar laser intensities. The hard X-ray yield from droplet plasmas is about 35 times more than that obtained from solid plasmas. A prepulse that is about 10ns and at least 2% in intensity of the main pulse is essential for hard x-ray generation from the droplets at about 1015 W cm-2. A hot electron temperature of 36 keV is measured from the droplets at 8 x 1014 W cm-2; three times higher intensity is needed to obtain similar hot electron temperature from solid plasmas that have similar atomic composition. We use 1D-PIC simulation to obtain qualitative correlation to the experimental observations.

  2. A laboratory model of post-Newtonian gravity with high power lasers and 4th generation light sources

    NASA Astrophysics Data System (ADS)

    Gregori, G.; Levy, M. C.; Wadud, M. A.; Crowley, B. J. B.; Bingham, R.

    2016-04-01

    Using the post-Newtonian formalism of gravity, we attempt to calculate the x-ray Thomson scattering cross section of electrons that are accelerated in the field of a high intensity optical laser. We show that our results are consistent with previous calculations, suggesting that the combination of high power laser and 4th generation light sources may become a powerful platform to test models exploring high order corrections to the Newtonian gravity.

  3. Bifrost: A 4th Generation Launch Architecture Concept

    NASA Astrophysics Data System (ADS)

    Rohrschneider, R. R.; Young, D.; St.Germain, B.; Brown, N.; Crowley, J.; Maatsch, J.; Olds, J. R.

    2002-01-01

    A 4th generation launch architecture is studied for the purpose of drastically reducing launch costs and hence enabling new large mass missions such as space solar power and human exploration of other planets. The architecture consists of a magnetic levitation launch tube placed on the equator with the exit end elevated to approximately 20 km. Several modules exist for sending manned and unmanned payloads into Earth orbit. Analysis of the launch tube operations, launch trajectories, module aerodynamics, propulsion modules, and system costs are presented. Using the hybrid logistics module, it is possible to place payloads into low Earth orbit for just over 100 per lb.

  4. Monochromatic plasma x-ray generator and its applications

    NASA Astrophysics Data System (ADS)

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

    1998-07-01

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

  5. Dual-energy flash x-ray generator

    NASA Astrophysics Data System (ADS)

    Sato, Eiichi; Sagae, Michiaki; Takahashi, Kei; Shikoda, Arimitsu; Oizumi, Teiji; Ojima, Hidenori; Takayama, Kazuyoshi; Tamakawa, Yoshiharu; Yanagisawa, Toru; Fujiwara, Akihiro; Mitoya, Kanji

    1995-05-01

    The fundamental studies on a dual-energy flash x-ray generator for performing the energy-selective two-direction radiography are described. This generator consisted of the following components: a negative high- voltage power supply, a polarity-inversion-type high-voltage pulser having a 5 nF combined ceramic condenser, a turbo molecular pump, and two flash x-ray tubes. The condenser in the pulser was charged from -60 to -80 kV, and the electric charges in the condenser were discharged to two x-ray tubes. The maximum output voltage from the pulser was about -1.5 times the charged voltage because the cable transmission line was employed. Using a tube, the maximum tube voltage was about 110 kV. The maximum tube current and the x-ray intensity were less than 3 kA and 5 (mu) C/kg at 0.5 m per pulse, respectively. In contrast, the tube current and the intensity has approximately half the above values when two tubes were employed. The pulse widths were less than 200 ns, and two shots of flash x rays were obtained simultaneously. Each photon energy of flash x rays can be changed by controlling the space between the anode and cathode electrodes.

  6. Repetitive Pulsed X-Ray Generator Utilizing A Triode

    NASA Astrophysics Data System (ADS)

    Sato, Eiichi; Kawasaki, Satoshi; Isobe, Hiroshi; Tamakawa, Yoshiharu; Yanagisawa, Toru

    1990-01-01

    A repetitive pulsed x-ray generator utilizing a triode for biomedical radiography is described. This generator consisted of the following components: a high-voltage power supply, a cable condenser with a length of 10m and a capacity of about 1000pF, a repetitive impulse switching system, a turbo molecular pump, and a pulsed x-ray tube having a cold cathode. The x-ray tube was of the triode type which was connected to the turbo molecular pump and consisted of the following components: a rod-shaped anode tip made of tungsten, a ring cathode made of molybdenum, a ring trigger electrode made of iron and other parts. The trigger electrode was attached to the cathode electrode just inside of the x-ray window and the space between the cathode and trigger electrodes was less than 0.5mm. The anode-cathode (A-C) space was adjusted outside of the x-ray window for controlling the A-C impedance. The cable condenser was charged from 30 to 100kV by the constant voltage generator and was discharged repetitively by the impulse switching system utilizing a frequency control system with a high time resolution. The maximum frequencies varied according to the charging voltage, the condenser capacity which was determined by the length of the cable condenser, and the current capacity of the high-voltage power supply. The frequencies of this generator were less than 100Hz, and the pulse widths of the pulsed x-rays were less than 300ns. The time integrated x-ray intensity was less than 5.0pC/kg at 0.5m per pulse, and the effective focal spot size ranged from 0.5 to 3.0mm.

  7. Toward a fourth-generation x-ray source.

    SciTech Connect

    Monction, D. E.

    1999-05-19

    The field of synchrotron radiation research has grown rapidly over the last 25 years due to both the push of the accelerator and magnet technology that produces the x-ray beams and the pull of the extraordinary scientific research that is possible with them. Three successive generations of synchrotrons radiation facilities have resulted in beam brilliances 11 to 12 orders of magnitude greater than the standard laboratory x-ray tube. However, greater advances can be easily imagined given the fact that x-ray beams from present-day facilities do not exhibit the coherence or time structure so familiar with the optical laser. Theoretical work over the last ten years or so has pointed to the possibility of generating hard x-ray beams with laser-like characteristics. The concept is based on self-amplified spontaneous emission (SASE) in flee-electron lasers. A major facility of this type based upon a superconducting linac could produce a cost-effective facility that spans wave-lengths from the ultraviolet to the hard x-ray regime, simultaneously servicing large numbers experimenters from a wide range of disciplines. As with each past generation of synchrotrons facilities, immense new scientific opportunities would result from fourth-generation sources.

  8. Polycapillary radiography using a quasi-x-ray-laser generator

    NASA Astrophysics Data System (ADS)

    Sato, Eiichi; Hayasi, Yasuomi; Tanaka, Etsuro; Mori, Hidezo; Kawai, Toshiaki; Obara, Haruo; Ichimaru, Toshio; Takayama, Kazuyoshi; Ido, Hideaki; Usuki, Tatsumi; Sato, Koetsu; Tamakawa, Yoshiharu

    2001-12-01

    The characteristics of a new quasi-x-ray laser generator and its application to polycapillary radiography are described. The generator employs a high-voltage power supply, a low- impedance coaxial transmission line, a high-voltage condenser with a capacity of about 200 nF, a turbo-molecular pump, a thyristor pulse generator as a trigger device, and a new plasma flash x-ray tube. The high-voltage main condenser is charged up to 60 kV by the power supply, and the electric charges in the condenser are discharged to the tube after triggering the cathode electrode. The flash x- rays are then produced. The x-ray tube is of a demountable triode that is connected to the turbo molecular pump with a pressure of approximately 1 mPa. As the electron flows from the cathode electrode are roughly converged to the copper target by the electric field in the tube, the plasma x-ray source, which consists of metal ions and electrons, forms by the target evaporating. Both the tube voltage and current displayed damped oscillations, and their peak values increased according to increase in the charging voltage. In the present work, the peak tube voltage was almost equal to the initial charging voltage of the main condenser, and the peak current was about 25 kA with a charging voltage of 60 kV. When the charging voltage was increased, the linear plasma x-ray source formed, and the characteristic x-ray intensities of K-series lines increased. In the radiogrpahy achieved with a computed radiography system, we employed a polycapilary plate with a hole diameter of 20 micrometers and a thickness of 1 mm. The image resolution was primarily determined by the resolution of the CR system and had a value of about 100micrometers .

  9. Echo-enabled x-ray vortex generation.

    PubMed

    Hemsing, E; Marinelli, A

    2012-11-30

    A technique to generate high-brightness electromagnetic vortices with tunable topological charge at extreme ultraviolet and x-ray wavelengths is described. Based on a modified version of echo-enabled harmonic generation for free-electron lasers, the technique uses two lasers and two chicanes to produce high-harmonic microbunching of a relativistic electron beam with a corkscrew distribution that matches the instantaneous helical phase structure of the x-ray vortex. The strongly correlated electron distribution emerges from an efficient three-dimensional recoherence effect in the echo-enabled harmonic generation transport line and can emit fully coherent vortices in a downstream radiator for access to new research in x-ray science. PMID:23368128

  10. Lightweight Target Generates Bright, Energetic X-Rays

    SciTech Connect

    Hazi, A

    2006-01-25

    Radiography with x rays is a long-established method to see inside objects, from human limbs to weapon parts. Livermore scientists have a continuing need for powerful x rays for such applications as backlighting, or illuminating, inertial confinement fusion (ICF) experiments and imaging still or exploding materials for the nation's Stockpile Stewardship Program. X-radiography is one of the prime diagnostics for ICF experiments because it captures the fine detail needed to determine what happens to nearly microscopic targets when they are compressed by laser light. For example, Livermore scientists participating in the National Ignition Facility's (NIF's) 18-month-long Early Light experimental campaign, which ended in 2004, used x rays to examine hydrodynamic instabilities in jets of plasma. In these experiments, one laser beam irradiated a solid target of titanium, causing it to form a high-temperature plasma that generated x rays of about 4.65 kiloelectronvolts (keV). These x rays backlit a jet of plasma formed when two other laser beams hit a plastic ablator and sent a shock to an aluminum washer. Livermore physicist Kevin Fournier of the Physics and Advanced Technologies Directorate leads a team that is working to increase the efficiency of converting laser energy into x rays so the resulting images provide more information about the object being illuminated. The main characteristics of x-ray sources are energy and brightness. ''As experimental targets get larger and as compression of the targets increases, the backlighter sources must be brighter and more energetic'', says Fournier. The more energetic the x rays, the further they penetrate an object. The brighter the source--that is, the more photons it has--the clearer the image. historically, researchers have used solid targets such as thin metal foils to generate x rays. however, when photon energies are greater than a few kiloelectronvolts, the conversion efficiency of solid targets is only a fraction of 1

  11. Progress in Development of Kharkov X-Ray Generator Nestor

    SciTech Connect

    Androsov, V.; Bulyak, V.; Dovbnya, A.; Drebot, I.; Gladkikh, P.; Grevtsev, V.; Grigorev, Yu.; Gvozd, A.; Ivashchenko, V.; Karnaukhov, I.; Kovalyova, N.; Kozin, V.; Lapshin, V.; Lyashchenko, V.; Markov, V.; Mocheshnikov, N.; Mytsykov, A.; Neklyudov, I.; Peev, F.; Rezaev, A.; Shcherbakov, A.; /Kharkov, KIPT /SLAC, SSRL /Eindhoven, Tech. U. /Lebedev Inst. /Kurdyumova Inst. Metalophysics

    2005-09-14

    The sources of the X-rays based on Compton scattering of intense Nd:YAG laser beam on electron beam circulating in a storage ring with beam energy 43-225 MeV is under construction in NSC KIPT. In the paper the progress in development and construction of Kharkov X-ray generator NESTOR is presented. The current status of the main facility system design and development are described. New scheme and main parameters of injection system are presented. The status of power supply system and control system is described. The facility is going to be in operation in the middle of 2007 and generated X-rays flux is expected to be of about 10{sup 13} phot/s.

  12. pyXSIM: Synthetic X-ray observations generator

    NASA Astrophysics Data System (ADS)

    ZuHone, John A., Hallman, Eric. J.

    2016-08-01

    pyXSIM simulates X-ray observations from astrophysical sources. X-rays probe the high-energy universe, from hot galaxy clusters to compact objects such as neutron stars and black holes and many interesting sources in between. pyXSIM generates synthetic X-ray observations of these sources from a wide variety of models, whether from grid-based simulation codes such as FLASH (ascl:1010.082), Enzo (ascl:1010.072), and Athena (ascl:1010.014), to particle-based codes such as Gadget (ascl:0003.001) and AREPO, and even from datasets that have been created “by hand”, such as from NumPy arrays. pyXSIM can also manipulate the synthetic observations it produces in various ways and export the simulated X-ray events to other software packages to simulate the end products of specific X-ray observatories. pyXSIM is an implementation of the PHOX (ascl:1112.004) algorithm and was initially the photon_simulator analysis module in yt (ascl:1011.022); it is dependent on yt.

  13. Tentative study on high-photon-energy quasi-x-ray laser generator by forming plasma x-ray source

    NASA Astrophysics Data System (ADS)

    Sato, Eiichi; Hayasi, Yasuomi; Ichimaru, Toshio; Mori, Hidezo; Tanaka, Etsuro; Ojima, Hidenori; Takayama, Kazuyoshi; Usuki, Tatsumi; Sato, Koetsu; Sakamaki, Kimio; Tamakawa, Yoshiharu

    2001-04-01

    Tentative study on high-photon-energy quasi-x-ray-laser generator by forming plasma x-ray source is described. The generator employs a high-voltage power supply, a low-impedance coaxial transmission line, a high-voltage condenser with a capacity of about 200 nF, a turbo-molecular pump, a thyristor pulse generator as a trigger device, and a flash x-ray tube. The high-voltage main condenser is charged up to 60 kV by the power supply, and the electric charges in the condenser are discharged to the tube after triggering the cathode electrode. The flash x-rays are then produced. The x-ray tube is of a demountable triode that is connected to the turbo molecular pump with a pressure of approximately 1 mPa. As the electron flows from the cathode electrode are roughly converged to the copper target by the electric field in the tube, the plasma x- ray source, which consists of metal ions and electrons, forms by the target evaporating. Both the tube voltage and current displayed damped oscillations, and their peak values increased according to increases in the charging voltage. In the present work, the peak tube voltage was much higher than the initial charging voltage of the main condenser, and the peak current was about 25 kA with a charging voltage of 60 kV. When the charging voltage was increased, the plasma x-ray source formed, and the characteristic x-ray intensities of K-series lines increased. When the plate target was employed, we observed high-intensity characteristic x-rays from the axial direction of the linear plasma x-ray source. In the case where the rod target was employed, we detected higher-intensity characteristic x-rays.

  14. Numerical simulations of x-ray generation in miltisectional FELs

    SciTech Connect

    Pitatelev, M.M.

    1995-12-31

    The process of x-ray generation in milticomponent FELs with alternate undulator and dispersion sections is investigate. The coptuter simulation was fulfilled for the ultrarelativistic electron beams. It was shown that the use of much number of dispersion sections allows to increase the gain considerably and to use more short magnetic systems.

  15. A Repetitional Pulsed X-Ray Generator For Biomedical Radiography

    NASA Astrophysics Data System (ADS)

    Isobe, Hiroshi; Sato, Eiichi; Tamakawa, Yoshiharu; Yanagisawa, Toru

    1989-06-01

    A repetitional pulsed x-ray generator in conjunction with an image intensifier system for biomedical radiography is described. This generator consisted of the following components: a high-speed power supply, various capacities of pulse condensers, a turbo molecular pump, and an oil-cooled x-ray tube. The pulse condensers were charged to the optimum voltage of less than 100kV, and the electric charges were discharged repeatedly by using the flashover mechanism. The pulse width tended to decrease when the capacity and the anode-cathode(A-C) space were reduced, and their values were less than 200ns. The current of the power supply determined the repetitional rates for the pulses, which were limited by the charging resistor, the condenser capacity, the charging voltage, and the electric power of the power supply. The maximum value was less than 20Hz due to the ripples of the charging current of 50Hz. The x-ray quality primarily became hard by increasing the charging voltage, and inserting metal filters. The effective focal spot size primarily varied according to the diameter of anode tip, and its size was less than 3.0mm in diameter. Pulsed x-ray fluoro-scopy was performed by using an image intensifier system utilizing a CRT for medical use.

  16. FY06 LDRD Final Report Next-generation x-ray optics: focusing hard x-rays

    SciTech Connect

    Pivovaroff, M; Soufli, R

    2007-03-01

    The original goal of our research was to open up a new class of scientific experiments by increasing the power of newly available x-ray sources by orders of magnitude. This was accomplished by developing a new generation of x-ray optics, based on hard x-ray (10-200 keV) reflective and diffractive focusing elements. The optical systems we envision begin with a core reflective optic, which has the ability to capture and concentrate x-rays across a wide range of energies and angles band, combined with diffractive optics, based on large-scale multilayer structures, that will further enhance the spatial, spectral and temporal resolving power of the system. Enabling technologies developed at LLNL such as precise mounting of thermally formed substrates, smoothing techniques and multilayer films of ultra-high reflectance and precision were crucial in the development and demonstration of our research objectives. Highlights of this phase of the project include: the design and fabrication of a concentrator optic for the Pleiades Thomson X-ray source located at LLNL, smoothing of glass substrates through application of polyimide films, and the design, fabrication and testing of novel volume multilayers structures. Part of our research into substrate smooth led to the development of a new technique (patent pending) to construct high-quality, inexpensive x-ray optics. This innovation resulted in LLNL constructing a x-ray optic for the CERN Axion Solar Telescope (CAST) and allowed LLNL to join the international experiment.

  17. ELECTRON INJECTORS FOR NEXT GENERATION X-RAY SOURCES.

    SciTech Connect

    BLUEM,H.; BEN-ZVI,I.; SRINIVASAN-RAO,T.; ET AL.

    2004-08-02

    Next generation x-ray sources require very high-brightness electron beams that are typically at or beyond the present state-of-the-art, and thus place stringent and demanding requirements upon the electron injector parameters. No one electron source concept is suitable for all the diverse applications envisaged, which have operating characteristics ranging from high-average-current, quasi-CW, to high-peak-current, single-pulse electron beams. Advanced Energy Systems, in collaboration with various partners, is developing several electron injector concepts for these x-ray source applications. The performance and design characteristics of five specific RF injectors, spanning ''L'' to ''X''-band, normal-conducting to superconducting, and low repetition rate to CW, which are presently in various stages of design, construction or testing, is described. We also discuss the status and schedule of each with respect to testing.

  18. Repetitive flash x-ray generator operated at low-dose rates for a medical x-ray television system

    NASA Astrophysics Data System (ADS)

    Sato, Eiichi; Isobe, Hiroshi; Takahashi, Kei; Tamakawa, Yoshiharu; Yanagisawa, Toru

    1991-04-01

    The fundamental studies for the repetitive flash x-ray generator operated at lowdose rates for a medical x-ray television system are described. This x-ray generator consisted of the following components: a high-voltage power supply, an energy storage condenser of lOOnF, a coaxial cable condenser with a capacity of l000pF, a repetitive impulse switching system, a turbo molecular pump, and an x-ray tube having a cold cathode. The condenser was charged from 40 to 70kV by a power supply, and the electric charges stored in the condenser were discharged repetitively by using a trigger electrode operated by an impulse switching system. The x-ray tube was of the triode-type which was connected to the turbo molecular pump and had a large discharge impedance in order to prevent the damped oscillations of the tube current and voltage. The maximum tube voltage was equivalent to the initial charged voltage, and the peak current was less than 70A. The durations were about 2ps, and the x-ray intensities were less than 1. OpC/kg at 0. 5m per pulse. The repetition frequency was less than 50Hz, and the effective focal spot size was equivalent to the anode diameter of 3. 0mm. For the x-ray television system used in conjunction with this repetitive pulsed x-ray generator, since the electromagnetic noise primarily caused by the high tube current was decreased, noise-free stroboscopic radiography performed by the television system could be realized.

  19. Next-generation X-ray cluster surveys

    NASA Astrophysics Data System (ADS)

    Slack, N. W.; Ponman, T. J.

    2014-03-01

    Contemporary X-ray surveys have permitted rich galaxy clusters to be detected out to redshifts z > 1, but studies with next-generation instruments will allow this work to be extended to both higher redshift and lower cluster masses. Such studies have the potential to provide powerful constraints on the evolution of baryonic processes such as cooling and feedback within developing cosmic structures, provided that observational selection effects can be controlled. To explore this, we generate simulated surveys using the Wide Field Imager (WFI) instrument on International X-ray Observatory (IXO), studied in 2010 by NASA and ESA as a major next-generation X-ray observatory. A sample of observed groups and clusters is assembled and used to derive relationships between temperature and four cluster properties: M500, L500, core radius and β. These are coupled with an evolving population of dark matter haloes drawn from the Millennium Simulation to construct an evolving set of X-ray clusters which are cast into a lightcone and imaged using the main instrumental characteristics of the IXO WFI. State-of-the-art techniques are then employed for source detection and extension testing, to generate a simulated survey cluster catalogue. These simulations are used to explore the dependence of a next-generation survey on the evolution of cluster scaling relations, survey strategy (wide versus deep) and instrument point spread function (PSF). We find that a 1.8 Ms IXO survey gives a cluster sample three to five times larger for a wide survey compared to a deep survey. In both surveys, the strongest discrimination between different LX-T evolutionary models derives from galaxy groups, with T ˜ 1-2 keV. Deep surveys can be affected by cosmic variance within this temperature range, whilst wide surveys suffer from incompleteness, and hence are more vulnerable to biases arising from incomplete knowledge of the survey selection function. Degrading the telescope PSF is found to most

  20. 3D registration through pseudo x-ray image generation.

    PubMed

    Domergue, G; Viant, W J

    2000-01-01

    One of the less effective processes within current Computer Assisted Surgery systems, utilizing pre-operative planning, is the registration of the plan with the intra-operative position of the patient. The technique described in this paper requires no digitisation of anatomical features or fiducial markers but instead relies on image matching between pseudo and real x-ray images generated by a virtual and a real image intensifier respectively. The technique is an extension to the work undertaken by Weese [1]. PMID:10977585

  1. Generation of Coherent X-Ray Radiation Through Modulation Compression

    SciTech Connect

    Qiang, Ji; Wu, Juhao

    2010-12-14

    In this letter, we propose a scheme to generate tunable coherent X-ray radiation for future light source applications. This scheme uses an energy chirped electron beam, a laser modulators, a laser chirper and two bunch compressors to generate a prebunched kilo-Ampere current electron beam from a few tens Ampere electron beam out of a linac. The initial modulation energy wavelength can be compressed by a factor of 1 + h{sub b}R{sub 56}{sup a} phase space, where h{sub b} is the energy bunch length chirp introduced by the laser chirper, R{sub 56}{sup a} is the momentum compaction factor of the first bunch compressor. As an illustration, we present an example to generate more than 400 MW, 170 atto-seconds pulse, 1 nm coherent X-ray radiation using a 60 Ampere electron beam out. of the linac and 200 nm laser seed. Both the final wavelength and the radiation pulse length in the proposed scheme are tunable by adjusting the compression factor and the laser parameters.

  2. Generation of Coherent X-Ray Radiation through Modulation Compression

    SciTech Connect

    Qiang, Ji; Wu, Juhao; /SLAC

    2012-06-12

    In this paper, we propose a scheme to generate tunable coherent X-ray radiation for future light source applications. This scheme uses an energy chirped electron beam, a laser modulator, a laser chirper and two bunch compressors to generate a prebunched kilo-Ampere current electron beam from a few tens Ampere electron beam out of a linac. The initial modulation energy wavelength can be compressed by a factor of 1 + h{sub b}R{sub 56}{sup a} in phase space, where h{sub b} is the energy bunch length chirp introduced by the laser chirper, R{sub 56}{sup a} is the momentum compaction factor of the first bunch compressor. As an illustration, we present an example to generate more than 400 MW, 170 attoseconds pulse, 1 nm coherent X-ray radiation using a 60 A electron beam out of the linac and 200 nm laser seed. Both the final wavelength and the radiation pulse length in the proposed scheme are tunable by adjusting the compression factor and the laser parameters.

  3. GENERATION OF SUBPICOSECOND X-RAY PULSES IN STORAGE RINGS

    SciTech Connect

    Zholents, Alexander A.

    2007-06-19

    Supicosecond x-ray pulses are routinely produced at ALS,BESSY and SLS with slicing technique and used in pump-probe experimentswith controlled delay between laser pump pulses and x-ray probe pulses.New development aiming for a production of a subpicosecond x-ray pulsesusing rf orbit deflection technique is under way at APS. Both techniqueswill be reviewed here.

  4. Compact high current generator for x-ray radiography

    NASA Astrophysics Data System (ADS)

    Kharlov, A. V.; Kovalchuk, B. M.; Zorin, V. B.

    2006-12-01

    We report here a design of the portable high current generator, which can be used for a row of experiments and applications, including, but not limited to, X pinch, plasma focus, vacuum spark, etc. The X generator consists of the capacitor bank, multigap spark switch, load chamber, and built-in high voltage triggering generator. The capacitor bank consists of 12 General Atomics 35404 type capacitors (20nF, 25nH, 0.2Ω, 100kV). It stores ˜0.8kJ at 80kV charging voltage. Each three capacitors are commuted to a load by the multigap spark switch, which is able to commute by eight parallel channels. Switches operate in ambient air at atmospheric pressure. At 76kV charging voltage the generator provides ˜260kA with 120ns rise time and 5nH inductive load and ˜220kA with 145ns rise time and 10nH. Delay of output pulse relative to high voltage triggering pulse is ˜65ns with 5ns jitter. The dimensions of the generator are 1240×1240×225mm3 and the weight is ˜250kg, and only one high voltage power supply is required as additional equipment for the generator. The generator with a pumping system is placed on area about 0.5m2. Operation and handling are very simple, because no oil nor purified gases are required for the generator. The X generator has been successfully employed for experiments on the Ni X pinch load. X-ray pulse duration (full width at half maximum above 1keV) was about 5ns. Radiation yield Wr⩾500mJ was observed in the 1.2-1.5KeV range and Wr⩾20mJ in the 3-5keV energy range, which is comparable to results, obtained on the nanosecond accelerators. Clearly resolved images of 6μm wire indicate micron level size of hot spot. These results demonstrate possibility of this generator for application for x-ray backlighting.

  5. X rays generated in the interaction of subpicosecond laser pulses with solid targets

    SciTech Connect

    Kyrala, G.A.; Wahlin, E.K.; Fulton, R.D.; Schappert, G.T.; Jones, L.A.; Taylor, A.J.; Casperson, D.E.; Cobble, J.A.

    1991-01-01

    We are investigating the generation of short pulse short wavelength x-rays for pumping inner-shell x-ray lasers by photo-ionization. In contrast with previous proposals, we are looking at the use of a single line as an efficient means of pumping these lasers. As a first step we are optimizing the flashlamp x-ray conversion efficiency and characterizing the x-ray pulse length. 18 refs., 5 figs., 2 tabs.

  6. 3D registration through pseudo x-ray image generation.

    PubMed

    Viant, W J; Barnel, F

    2001-01-01

    Registration of a pre operative plan with the intra operative position of the patient is still a largely unsolved problem. Current techniques generally require fiducials, either artificial or anatomic, to achieve the registration solution. Invariably these fiducials require implantation and/or direct digitisation. The technique described in this paper requires no digitisation or implantation of fiducials, but instead relies on the shape and form of the anatomy through a fully automated image comparison process. A pseudo image, generated from a virtual image intensifier's view of a CT dataset, is intra operatively compared with a real x-ray image. The principle is to align the virtual with the real image intensifier. The technique is an extension to the work undertaken by Domergue [1] and based on original ideas by Weese [4]. PMID:11317805

  7. Synchronous time-resolved optical and x-ray emission from simultaneous optical and x-ray streak cameras driven by a master ramp generator

    SciTech Connect

    Balmer, J.E.; Lampert, W.; Roschger, E.; Hares, J.D.; Kilkenny, J.D.

    1985-05-01

    An optical and an x-ray streak camera have been synchronized by driving the deflection plates of both cameras from the same ramp generator. The relative timing of the two cameras was calibrated by running UV light onto the x-ray streak camera. The x-ray streak camera was then used to measure the time of the x-ray emission from a laser plasma with respect to the laser pulse.

  8. JLab CW Cryomodules for 4th Generation Light Sources

    SciTech Connect

    Rimmer, Robert; Bundy, Richard; Cheng, Guangfeng; Ciovati, Gianluigi; Clemens, William; Daly, Edward; Henry, James; Hicks, William; Kneisel, Peter; Manning, Stephen; Manus, Robert; Marhauser, Frank; Preble, Joseph; Reece, Charles; Smith, Karl; Stirbet, Mircea; Turlington, Larry; Wang, Haipeng; Wilson, Katherine

    2008-01-23

    Fourth generation light sources hold the prospect of unprecedented brightness and optical beam quality for a wide range of scientific applications. Many of the proposed new facilities will rely on large superconducting radio frequency (SRF) based linacs to provide high energy, low emittance CW electron beams. For high average power applications there is a growing acceptance of energy recovery linac (ERL) technology as the way to support large recirculating currents with modest RF power requirements. CW SRF and high current ERLs are two core competencies at Jefferson Lab. JLab has designed and built a number of CW cryomodules of several different types starting with the original CEBAF design, with variations for higher current in the two generations of JLab’s free-electron laser (FEL), through two intermediate prototypes to the final high-performance module for the 12 GeV upgrade. Each of these represent fully engineered and tested configurations with a variety of specifications that could be considered for possible use in fourth generation light sources. Furthermore JLab has been actively pursuing advanced concepts for highcurrent high-efficiency cryomodules for next generation ERL based FEL’s. These existing and proposed designs span the range from about 1mA single-pass to over 100 mA energy recovered current capability. Specialized configurations also exist for high-current non-energy recovered sections such as the injector region where very high RF power is required. We discuss the performance parameters of these existing and proposed designs and their suitability to different classes of fourth generation light sources.

  9. TID Test Results for 4th Generation iPad(TradeMark)

    NASA Technical Reports Server (NTRS)

    Guertin, S. M.; Allen, G. R.; McClure, S. S.; LaBel, K. A.

    2013-01-01

    TID testing of 4th generation iPads is reported. Of iPad subsystems, results indicate that the charging circuitry and display drivers fail at lowest TID levels. Details of construction are investigated for additional testing of components.

  10. The 4th Generation Light Source at Jefferson Lab

    SciTech Connect

    Stephen Benson; George Biallas; James Boyce; Donald Bullard; James Coleman; David Douglas; H. Dylla; Richard Evans; Pavel Evtushenko; Albert Grippo; Christopher Gould; Joseph Gubeli; David Hardy; Carlos Hernandez-Garcia; Kevin Jordan; John Klopf; Steven Moore; George Neil; Thomas Powers; Joseph Preble; Daniel Sexton; Michelle D. Shinn; Christopher Tennant; Richard Walker; Shukui Zhang; Gwyn Williams

    2007-04-25

    A number of "Grand Challenges" in Science have recently been identified in reports from The National Academy of Sciences, and the U.S. Dept. of Energy, Basic Energy Sciences. Many of these require a new generation of linac-based light source to study dynamical and non-linear phenomena in nanoscale samples. In this paper we present a summary of the properties of such light sources, comparing them with existing sources, and then describing in more detail a specific source at Jefferson Lab. Importantly, the JLab light source has developed some novel technology which is a critical enabler for other new light sources.

  11. The 4th generation light source at Jefferson Lab

    NASA Astrophysics Data System (ADS)

    Benson, S.; Biallas, G.; Boyce, J.; Bullard, D.; Coleman, J.; Douglas, D.; Dylla, F.; Evans, R.; Evtushenko, P.; Grippo, A.; Gould, C.; Gubeli, J.; Hardy, D.; Hernandez-Garcia, C.; Jordan, K.; Klopf, J. M.; Moore, W.; Neil, G.; Powers, T.; Preble, J.; Sexton, D.; Shinn, M.; Tennant, C.; Walker, R.; Zhang, S.; Williams, G. P.

    2007-11-01

    A number of "Grand Challenges" in Science have recently been identified in reports from The National Academy of Sciences, and the US Department of Energy, Basic Energy Sciences. Many of these require a new generation of linac-based light source to study dynamical and non-linear phenomena in nanoscale samples. In this paper we present a summary of the properties of such light sources, comparing them with existing sources, and then describing in more detail a specific source at Jefferson Lab (JLab). Importantly, the JLab light source has developed some novel technology which is a critical enabler for other new light sources.

  12. Characterization of X-ray generator beam profiles.

    SciTech Connect

    Mitchell, Dean J; Harding, Lee T.; Thoreson, Gregory G.; Theisen, Lisa Anne; Parmeter, John Ethan; Thompson, Kyle Richard

    2013-07-01

    T to compute the radiography properties of various materials, the flux profiles of X-ray sources must be characterized. This report describes the characterization of X-ray beam profiles from a Kimtron industrial 450 kVp radiography system with a Comet MXC-45 HP/11 bipolar oil-cooled X-ray tube. The empirical method described here uses a detector response function to derive photon flux profiles based on data collected with a small cadmium telluride detector. The flux profiles are then reduced to a simple parametric form that enables computation of beam profiles for arbitrary accelerator energies.

  13. 21 CFR 892.1700 - Diagnostic x-ray high voltage generator.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Diagnostic x-ray high voltage generator. 892.1700 Section 892.1700 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... generator. (a) Identification. A diagnostic x-ray high voltage generator is a device that is intended...

  14. 21 CFR 892.1700 - Diagnostic x-ray high voltage generator.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Diagnostic x-ray high voltage generator. 892.1700 Section 892.1700 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... generator. (a) Identification. A diagnostic x-ray high voltage generator is a device that is intended...

  15. 21 CFR 892.1700 - Diagnostic x-ray high voltage generator.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Diagnostic x-ray high voltage generator. 892.1700 Section 892.1700 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... generator. (a) Identification. A diagnostic x-ray high voltage generator is a device that is intended...

  16. 21 CFR 892.1700 - Diagnostic x-ray high voltage generator.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Diagnostic x-ray high voltage generator. 892.1700 Section 892.1700 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... generator. (a) Identification. A diagnostic x-ray high voltage generator is a device that is intended...

  17. 21 CFR 892.1700 - Diagnostic x-ray high voltage generator.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Diagnostic x-ray high voltage generator. 892.1700 Section 892.1700 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... generator. (a) Identification. A diagnostic x-ray high voltage generator is a device that is intended...

  18. Comparison of Single Event Transients Generated by Short Pulsed X-Rays, Lasers and Heavy Ions

    SciTech Connect

    Cardoza, David; LaLumondiere, Stephen D.; Tockstein, Michael A.; Brewe, Dale L.; Wells, Nathan P.; Koga, Rokutaro; Gaab, K. M.; Lotshaw, William T.; Moss, Steven C.

    2014-12-01

    We report an experimental study of the transients generated by pulsed x-rays, heavy ions, and different laser wavelengths in a Si p-i-n photodiode. We compare the charge collected by all of the excitation methods to determine the equivalent LET for pulsed x-rays relative to heavy ions. Our comparisons show that pulsed x-rays from synchrotron sources can generate a large range of equivalent LET and generate transients similar to those excited by laser pulses and heavy ion strikes. We also look at how the pulse width of the transients changes for the different excitation methods. We show that the charge collected with pulsed x-rays is greater than expected as the x-ray photon energy increases. Combined with their capability of focusing to small spot sizes and of penetrating metallization, pulsed x-rays are a promising new tool for high resolution screening of SEE susceptibility

  19. Next generation x-ray all-sky monitor

    SciTech Connect

    Priedhorsky, W. C.; Peele, A. G.; Nugent, K. A.

    1997-01-10

    We set forth a conceptual design for x-ray all-sky monitor based on lobster-eye wide-field telescopes. This instrument, suitable for a small satellite, would monitor the flux of objects as faint as 2x10{sup -15} W/m{sup 2} (0.5-2.4 keV) on a daily basis with a signal-to-noise of 5. Sources would be located to 1-2 arc-minutes. Detailed simulations show that crosstalk from the cruciform lobster images would not significantly compromise performance. At this sensitivity limit, we could monitor not just x-ray binaries but fainter classes of x-ray sources. Hundreds of active galactic nuclei, coronal sources, and cataclysmic variables could be tracked on a daily basis. Large numbers of fast transients should be visible, including gamma-ray bursts and the soft x-ray breakout of nearby type II supernovae. Long-term x-ray measurements will advance our understanding of the geometries and perhaps masses of AGN, and coronal energy sources in stars.

  20. Long life electrodes for large-area x-ray generators

    NASA Technical Reports Server (NTRS)

    Rothe, Dietmar E. (Inventor)

    1991-01-01

    This invention is directed to rugged, reliable, and long-life electrodes for use in large-area, high-current-density electron gun and x-ray generators which are employed as contamination-free preionizers for high-energy pulsed gas lasers. The electron source at the cathode is a corona plasma formed at the interface between a conductor, or semiconductor, and a high-permittivity dielectric. Detailed descriptions are provided of a reliable cold plasma cathode, as well as an efficient liquid-cooled electron beam target (anode) and x-ray generator which concentrates the x-ray flux in the direction of an x-ray window.

  1. X-ray Measurements of a Thermo Scientific P385 DD Neutron Generator

    SciTech Connect

    E.H. Seabury; D.L. Chichester; A.J. Caffrey; J. Simpson; M. Lemchak; C.J. Wharton

    2001-08-01

    Idaho National Laboratory is experimenting with electrical neutron generators, as potential replacements for californium-252 radioisotopic neutron sources in its PINS prompt gamma-ray neutron activation analysis (PGNAA) system for the identification of military chemical warfare agents and explosives. In addition to neutron output, we have recently measured the x-ray output of the Thermo Scientific P385 deuterium-deuterium neutron generator. X-rays are a normal byproduct from a neutron generator and depending on their intensity and energy they can interfere with gamma rays from the object under test, increase gamma-spectrometer dead time, and reduce PGNAA system throughput. The P385 x-ray energy spectrum was measured with a high-purity germanium (HPGe) detector, and a broad peak is evident at about 70 keV. To identify the source of the x-rays within the neutron generator assembly, it was scanned by collimated scintillation detectors along its long axis. At the strongest x-ray emission points, the generator also was rotated 60° between measurements. The scans show the primary source of x-ray emission from the P385 neutron generator is an area 60 mm from the neutron production target, in the vicinity of the ion source. Rotation of the neutron generator did not significantly alter the x-ray count rate, and the x-ray emission appears to be axially symmetric within the neutron generator.

  2. An x-ray probe of nickel nanoparticles generated by laser ablation

    NASA Astrophysics Data System (ADS)

    Lehmann, C. S.; Doumy, G.; Southworth, S. H.; March, A. M.; Dichiara, A. D.; Gao, Y.; Kanter, E. P.; Krässig, B.; Moonshiram, D.; Young, L.; Chapman, K. W.; Chupas, P. J.

    2014-05-01

    A plume of nickel atoms and nanoparticles can be generated by an intense laser pulse hitting a solid nickel surface. We set up a Ni ablation source in a vacuum chamber on an x-ray beamline at the Advanced Photon Source and used x-ray absorption, x-ray emission, and ion spectroscopies to probe the ablation plume at x-ray energies above the Ni K-edge at 8.33 keV. The laser and x-ray pulses were overlapped in time and space with variable delay to measure the time evolution of the ablation plume. Measurements of the charge states produced by x-ray absorption were not possible due to the intense prompt ions ejected in the ablation process. However, Ni K α x-ray emission was measured as functions of laser fluence and pump-probe delay. The fluorescence yield was also used to record the near-edge x-ray absorption spectrum of the nanoparticles in the plume. The nanoparticles were collected and their diameters were determined to be ~9 nm from x-ray scattering pair-distribution-function measurements. The experiments demonstrate the use of x-ray techniques to characterize laser ablation processes. Work supported by the Chemical Sciences, Geosciences, and Biosciences Division, Office of Basic Energy Sciences, Office of Science, US Dept of Energy, Contract DE-AC02-06CH11357.

  3. Optimization of a femtosecond laser generated x-ray source for pulsed radiography

    NASA Astrophysics Data System (ADS)

    Chen, XiaoHui; Li, XiaoYa; Ma, YunCan; Wu, ZhaoKui; Li, Jun; Zhu, WenJun

    2016-01-01

    X-ray radiography is an important tool in medicine as well as in life science and materials science. It is Kα radiation that is of primary interest in the fields of x-ray diffraction, whereas the whole x-ray flux receives most attention in the x-ray imaging application. We present a general Monte Carlo model of x-ray generation in femtosecond laser-irradiated solid material. Bremsstrahlung radiation is taken into account explicitly, permitting both whole x-ray and Kα emission to be calculated for arbitrary experimental conditions (i.e. target material, target thickness, target shape as well as laser intensity). The optimal thickness of both the whole x-ray and Kα emission from Titanium (Ti) foils irradiated with femtosecond laser pulse has been investigated. Comparing the results of whole x-ray with those of the Kα radiation, we find that the optimal thickness is increased by up to 118% for laser intensities I<5×1017 W/cm2, and this in turn leads to an increase in x-ray flux by 8%. The model may thus serve as a guide for experiments, particularly for hard x-ray radiography applications.

  4. The AAPM/RSNA physics tutorial for residents. X-ray generators.

    PubMed

    Seibert, J A

    1997-01-01

    The x-ray generator delivers the electrical power to energize the x-ray tube and permits the selection of x-ray energy, x-ray quantity, and exposure time. Major internal components of the generator include transformers, diodes and rectifier circuits, filament and stator circuits, timer switches, and kilovolt and milliampere meters. Single-phase, three-phase, high-frequency, and constant potential generators produce different voltage waveforms (ripple) and x-ray beam spectra. Phototimer and automatic brightness control subsystems measure radiation exposure incident on the image receptor to give instantaneous feedback for optimal radiographic film densities and fluoroscopic image brightness, respectively. At the generator control console, the operator sets the tube voltage, tube current, exposure time, phototimer film density, spot film acquisition, and fluoroscopic parameters. Selection of generator power and options depends on the intended clinical use. X-ray tube focal spot size and power loading capability should be matched to the x-ray generator and clinical imaging requirements. Single and multiple exposure rating charts as well as anode and housing thermal characteristic charts indicate power input and dissipation rates specific to a generator and x-ray tube target and housing. PMID:9397462

  5. X-ray generation by inverse Compton scattering at the superconducting RF test facility

    NASA Astrophysics Data System (ADS)

    Shimizu, Hirotaka; Akemoto, Mitsuo; Arai, Yasuo; Araki, Sakae; Aryshev, Alexander; Fukuda, Masafumi; Fukuda, Shigeki; Haba, Junji; Hara, Kazufumi; Hayano, Hitoshi; Higashi, Yasuo; Honda, Yosuke; Honma, Teruya; Kako, Eiji; Kojima, Yuji; Kondo, Yoshinari; Lekomtsev, Konstantin; Matsumoto, Toshihiro; Michizono, Shinichiro; Miyoshi, Toshinobu; Nakai, Hirotaka; Nakajima, Hiromitsu; Nakanishi, Kota; Noguchi, Shuichi; Okugi, Toshiyuki; Sato, Masato; Shevelev, Mikhail; Shishido, Toshio; Takenaka, Tateru; Tsuchiya, Kiyosumi; Urakawa, Junji; Watanabe, Ken; Yamaguchi, Seiya; Yamamoto, Akira; Yamamoto, Yasuchika; Sakaue, Kazuyuki; Hosoda, Seiichi; Iijima, Hokuto; Kuriki, Masao; Tanaka, Ryuta; Kuramoto, Ayaka; Omet, Mathieu; Takeda, Ayaki

    2015-02-01

    Quasi-monochromatic X-rays with high brightness have a broad range of applications in fields such as life sciences, bio-, medical applications, and microlithography. One method for generating such X-rays is via inverse Compton scattering (ICS). X-ray generation experiments using ICS were carried out at the superconducting RF test facility (STF) accelerator at KEK. A new beam line, newly developed four-mirror optical cavity system, and new X-ray detector system were prepared for experiments downstream section of the STF electron accelerator. Amplified pulsed photons were accumulated into a four-mirror optical cavity and collided with an incoming 40 MeV electron beam. The generated X-rays were detected using a microchannel plate (MCP) detector for X-ray yield measurements and a new silicon-on-insulator (SOI) detector system for energy measurements. The detected X-ray yield by the MCP detector was 1756.8±272.2 photons/(244 electron bunches). To extrapolate this result to 1 ms train length under 5 Hz operations, 4.60×105 photons/1%-bandwidth were obtained. The peak X-ray energy, which was confirmed by the SOI detector, was 29 keV, and this is consistent with ICS X-rays.

  6. Ultrashort hard x-ray pulses generated by 90 degrees Thomson scattering

    SciTech Connect

    Chin, A.H.; Schoenlein, R.W.; Glover, T.E.

    1997-04-01

    Ultrashort x-ray pulses permit observation of fast structural dynamics in a variety of condensed matter systems. The authors have generated 300 femtosecond, 30 keV x-ray pulses by 90 degrees Thomson scattering between femtosecond laser pulses and relativistic electrons. The x-ray and laser pulses are synchronized on a femtosecond time scale, an important prerequisite for ultrafast pump-probe spectroscopy. Analysis of the x-ray beam properties also allows for electron bunch characterization on a femtosecond time scale.

  7. X-Ray Measurements Of A Thermo Scientific P385 DD Neutron Generator

    SciTech Connect

    Wharton, C. J.; Seabury, E. H.; Chichester, D. L.; Caffrey, A. J.; Simpson, J.; Lemchak, M.

    2011-06-01

    Idaho National Laboratory is experimenting with electrical neutron generators, as potential replacements for californium-252 radioisotopic neutron sources in its PINS prompt gamma-ray neutron activation analysis (PGNAA) system for the identification of military chemical warfare agents and explosives. In addition to neutron output, we have recently measured the x-ray output of the Thermo Scientific P385 deuterium-deuterium neutron generator. X rays are a normal byproduct from neutron generators, but depending on their intensity and energy, x rays can interfere with gamma rays from the object under test, increase gamma-spectrometer dead time, and reduce PGNAA system throughput. The P385 x-ray energy spectrum was measured with a high-purity germanium (HPGe) detector, and a broad peak is evident at about 70 keV. To identify the source of the x rays within the neutron generator assembly, it was scanned by collimated scintillation detectors along its long axis. At the strongest x-ray emission points, the generator also was rotated 60 deg. between measurements. The scans show the primary source of x-ray emission from the P385 neutron generator is an area 60 mm from the neutron production target, in the vicinity of the ion source. Rotation of the neutron generator did not significantly alter the x-ray count rate, and its x-ray emission appears to be axially symmetric. A thin lead shield, 3.2 mm (1/8 inch) thick, reduced the 70-keV generator x rays to negligible levels.

  8. Generation of Femtosecond X-Rays by 90 degrees Compton Scattering

    SciTech Connect

    Kim, K.-J.; Chattopadhyay, S.; Shank, C.V.

    1992-12-01

    We propose Compton scattering of a short pulse visible laser beam by a low energy (but relativistic) electron beam at a right angle for generation of femtosecond x-rays. Simple analysis to determine the qualitative and quantitative characteristics of the x-ray pulse is presented.

  9. Thermal management of next-generation contact-cooled synchrotron x-ray mirrors

    SciTech Connect

    Khounsary, A.

    1999-10-29

    In the past decade, several third-generation synchrotrons x-ray sources have been constructed and commissioned around the world. Many of the major problems in the development and design of the optical components capable of handling the extremely high heat loads of the generated x-ray beams have been resolved. It is expected, however, that in the next few years even more powerful x-ray beams will be produced at these facilities, for example, by increasing the particle beam current. In this paper, the design of a next generation of synchrotron x-ray mirrors is discussed. The author shows that the design of contact-cooled mirrors capable of handing x-ray beam heat fluxes in excess of 500 W/mm{sup 2} - or more than three times the present level - is well within reach, and the limiting factor is the thermal stress rather then thermally induced slope error.

  10. Weakly ionized plasma flash x-ray generator and its distinctive characteristics

    NASA Astrophysics Data System (ADS)

    Sato, Eiichi; Hayasi, Yasuomi; Germer, Rudolf; Murakami, Kazunori; Koorikawa, Yoshitake; Tanaka, Etsuro; Mori, Hidezo; Kawai, Toshiaki; Ichimaru, Toshio; Obata, Fumiko; Takahashi, Kiyomi; Sato, Sigehiro; Takayama, Kazuyoshi; Ido, Hideaki

    2004-01-01

    In the plasma flash x-ray generator, a high-voltage main condenser of approximately 200 nF is charged up to 50 kV by a power supply, and electric charges in the condenser are discharged to an x-ray tube after triggering the cathode electrode. The flash x-rays are then produced. The x-ray tube is a demountable triode that is connected to a turbo molecular pump with a pressure of approximately 1 mPa. As electron flows from the cathode electrode are roughly converged to a rod copper target of 3.0 mm in diameter by the electric field in the x-ray tube, weakly ionized linear plasma, which consists of copper ions and electrons, forms by target evaporation. At a charging voltage of 50 kV, the maximum tube voltage was almost equal to the charging voltage of the main condenser, and the peak current was about 15 kA. When the charging voltage was increased, the linear plasma formed, and the K-series characteristic x-ray intensities increased. The K-series lines were quite sharp and intense, and hardly any bremsstrahlung rays were detected. The x-ray pulse widths were approximately 700 ns, and the time-integrated x-ray intensity had a value of approximately 30 μC/kg at 1.0 m from the x-ray source with a charging voltage of 50 kV.

  11. An optimal target-filter system for electron beam generated x-ray spectra

    SciTech Connect

    Hsu, Hsiao-Hua; Vasilik, D.G.; Chen, J.

    1994-04-01

    An electron beam generated x-ray spectrum consists of characteristic x rays of the target and continuous bremsstrahlung. The percentage of characteristic x rays over the entire energy spectrum depends on the beam energy and the filter thickness. To determine the optimal electron beam energy and filter thickness, one can either conduct many experimental measurements, or perform a series of Monte Carlo simulations. Monte Carlo simulations are shown to be an efficient tool for determining the optimal target-filter system for electron beam generated x-ray spectra. Three of the most commonly used low-energy x-ray metal targets (Cu, Zn and Mo) are chosen for this study to illustrate the power of Monte Carlo simulations.

  12. A small, battery-operated fluoroscopic system - Lixiscope with X-ray generator

    NASA Technical Reports Server (NTRS)

    Yin, L. I.; Trombka, J. I.; Ruitberg, A. P.; Seltzer, S. M.

    1983-01-01

    A small, battery-operated X-ray generator has been developed to be used as part of a small-format fluoroscopic system, the Lixiscope (Low Intensity X-ray Imaging Scope). The X-ray generator consists of a grounded rod-anode X-ray tube with a 0.2 mm focal spot and a specially designed, battery-operated, 0 to -80 kV high-voltge supply. Total power consumption is about 10 W. The fine focal spot, in conjunction with the continuously variable X-ray intensity and spectral distribution, helps to extend both the versatility and the performance of the Lixiscope toward a much wider range of terrestrial and spacecraft applications. The complete fluoroscopic system is described, and some examples of possible applications are shown.

  13. Miniature, low-power X-ray tube using a microchannel electron generator electron source

    NASA Technical Reports Server (NTRS)

    Elam, Wm. Timothy (Inventor); Kelliher, Warren C. (Inventor); Hershyn, William (Inventor); DeLong, David P. (Inventor)

    2011-01-01

    Embodiments of the invention provide a novel, low-power X-ray tube and X-ray generating system. Embodiments of the invention use a multichannel electron generator as the electron source, thereby increasing reliability and decreasing power consumption of the X-ray tube. Unlike tubes using a conventional filament that must be heated by a current power source, embodiments of the invention require only a voltage power source, use very little current, and have no cooling requirements. The microchannel electron generator comprises one or more microchannel plates (MCPs), Each MCP comprises a honeycomb assembly of a plurality of annular components, which may be stacked to increase electron intensity. The multichannel electron generator used enables directional control of electron flow. In addition, the multichannel electron generator used is more robust than conventional filaments, making the resulting X-ray tube very shock and vibration resistant.

  14. Intrapulse x-ray parametric amplification in high-order-harmonic generation

    NASA Astrophysics Data System (ADS)

    Serrat, Carles

    2016-06-01

    We demonstrate strong-field-driven impulsive XUV-x-ray parametric amplification (IXPA) processes in high-order harmonic generation at the single-atom level by using ab initio calculations. We consider the example of Li+ ions exposed simultaneously to an intense IR pulse and a weak 200-as XUV-x-ray pulse with central photon energies varying from 90 to 400 eV. We determine optimal parameter ranges and the precise delays between the IR and the XUV-x-ray pulses for IXPA to occur. The present results might be a guide to achieve exponential growth of the XUV-x-ray signal in tabletop XUV-x-ray lasers.

  15. Optics Requirements For The Generation-X X-Ray Telescope

    NASA Technical Reports Server (NTRS)

    O'Dell, S. .; Elsner, R. F.; Kolodziejczak, J. J.; Ramsey, B. D.; Weisskopf, M. C.; Zhang, W. W.; Content, D. A.; Petre, R.; Saha, T. T.; Reid, P. B.; Schwartz, D. A.; Brissenden, R. J.; Elvis, M.; Freeman, M.; Gaetz, T.; Gorenstein, P.; Jerius, D.; Juda, M.; Murray, S. S.; Podgorski, W. A.; Wolk, S. J.; Trolier-McKinstry, S.

    2008-01-01

    US, European, and Japanese space agencies each now operate successful X-ray missions -- NASA s Chandra, ESA s XMM-Newton, and JAXA s Suzaku observatories. Recently these agencies began a collaboration to develop the next major X-ray astrophysics facility -- the International X-ray Observatory (IXO) -- for launch around 2020. IXO will provide an order-of-magnitude increase in effective area, while maintaining good (but not sub-arcsecond) angular resolution. X-ray astronomy beyond IXO will require optics with even larger aperture areas and much better angular resolution. We are currently conducting a NASA strategic mission concept study to identify technology issues and to formulate a technology roadmap for a mission -- Generation-X (Gen-X) -- to provide these capabilities. Achieving large X-ray collecting areas in a space observatory requires extremely lightweight mirrors.

  16. Apparatus for setting exposure parameters of an X-ray generator

    SciTech Connect

    Kasa, Z.; Farkas, I.

    1989-03-07

    Apparatus is described for setting exposure parameters of an X-ray generator comprising: (a) an X-ray tube transformer, (b) a plurality of output terminals, on the X-ray tube transformer, (c) switching means connected to the output terminals, (d) a pair of high voltage lines selectively coupled to the output terminals by the switching means, (e) an X-ray tube, (f) exposure switching to the X-ray tube during a predetermined exposure period, (g) exposure means for determining a starting moment of an exposure period, (h) setting means for determining dosage of the exposure, (i) a filament transformer for heating a filament of the tube, (j) filament supply means for coupling a filament current selectable from a plurality of discrete current values to the filament transformer, and (k) a processor.

  17. Low-photon-energy plasma flash x-ray generator (LPFXG-2002)

    NASA Astrophysics Data System (ADS)

    Komatsu, Makoto; Sato, Eiichi; Hayasi, Yasuomi; Usuki, Tatsumi; Sato, Koetsu; Tanaka, Etsuro; Mori, Hidezo; Ojima, Hidenori; Takayama, Kazuyoshi; Ido, Hideaki

    2003-07-01

    In this study, we have made a low photon energy flash x-ray generator with a titanium target and have measured the radiographic characteristics. The flash x-ray generator consists of a high-voltage power supply, a high-voltage condenser, a turbo molecular pump and a flash x-ray tube. The condenser is charged up to about 30 kV, and the electric charges in the condenser are discharged to the tube after triggering the cathode. The linear plasma x-ray source forms from the target evaporation, and then the flash x-rays are generated from the plasma in the axial direction. K-series emission of titanium has been confirmed in experiments qualitatively and characteristics of the generator have been measured. K-series x-ray of titanium had a high resolution and enable us to take radiographs of a thin rabbit's ear clearly using the CR (Computed Radiography) system. The effect of titanium on the target of the soft flash x-ray tube has been indicated accordingly.

  18. Fundamental Studies For The Triple-Flash X-Ray Generator For Biomedical Radiography

    NASA Astrophysics Data System (ADS)

    Sato, Eiichi; Kawasaki, Satoshi; Isobe, Hiroshi; Tamakawa, Yoshiharu; Yanagisawa, Toru

    1989-06-01

    The fundamental studies for the triple-flash x-ray generator having variable spectra for biomedical radiography are described. Two types of triple-flash x-ray generators consisted of the following components: a high-voltage generating unit, a voltage divider unit, three high-voltage pulsers, a triple-parallel impulse switching system utilizing air gap pulsers for the main gas gaps, a high-power gas diode having three terminals, a turbo molecular pump, and three x-ray tubes having cold cathodes. For the single-tube generator, the pulse condensers of the pulsers were charged to the same or different energies by using a voltage divider unit and were connected to the x-ray tube through a high-power gas diode. In contrast, the pulsers were connected directly to three tubes without a diode. The duration of each x-ray pulse was a few ps, and the minimum time interval between two pulses was about 100ps (single-tube type), the x-ray intensity was less than lx10-5C/kg at lm per pulse, and the effective focal spot size was determined by the diameter of the anode rod. The triple exposure of pulsed x-rays having variable spectra and time intervals was obtained.

  19. Laser-driven hard-x-ray generation based on ultrafast selected energy x-ray absorption spectroscopy measurements of Ni compounds

    SciTech Connect

    Shan Fang; Carter, Josh D.; Ng, Vicky; Guo Ting

    2005-02-01

    Three Ni compounds were studied by ultrafast selected energy x-ray absorption spectroscopy using a laser-driven electron x-ray source with a tungsten target. The measured K edges of these Ni compounds using this self-referencing method were made identical to those measured with synchrotron x-ray sources. This enabled us to determine the absolute peak positions of tungsten L{alpha}{sub 1} and L{alpha}{sub 2} emitted from this source to be within 1 eV of those from the neutral tungsten atoms, which strongly suggested that the x rays were emitted from high energy electrons interacting with tungsten atoms in the solid target. This is the best evidence to date that directly supports the cold atom x-ray generation theory.

  20. Coherent hard x rays from attosecond pulse train-assisted harmonic generation.

    PubMed

    Klaiber, Michael; Hatsagortsyan, Karen Z; Müller, Carsten; Keitel, Christoph H

    2008-02-15

    High-order harmonic generation from atomic systems is considered in the crossed fields of a relativistically strong infrared laser and a weak attosecond pulse train of soft x rays. Due to one-photon ionization by the x-ray pulse, the ionized electron obtains a starting momentum that compensates the relativistic drift, which is induced by the laser magnetic field, and allows the electron to efficiently emit harmonic radiation upon recombination with the atomic core in the relativistic regime. This way, short pulses of coherent hard x rays of up to 40 keV energy can be generated. PMID:18278127

  1. Accuracy evaluation of a Compton X-ray spectrometer with bremsstrahlung X-rays generated by a 6 MeV electron bunch

    SciTech Connect

    Kojima, Sadaoki Arikawa, Yasunobu; Zhang, Zhe; Ikenouchi, Takahito; Morace, Alessio; Nagai, Takahiro; Abe, Yuki; Sakata, Shouhei; Inoue, Hiroaki; Utsugi, Masaru; Nakai, Mitsuo; Nishimura, Hiroaki; Shiraga, Hiroyuki; Fujioka, Shinsuke; Azechi, Hiroshi; Nishimura, Yasuhiko; Togawa, Hiromi; Ozaki, Tetsuo; Kato, Ryukou

    2014-11-15

    A Compton-scattering-based X-ray spectrometer is developed to obtain the energy distribution of fast electrons produced by intense laser and matter interactions. Bremsstrahlung X-rays generated by fast electrons in a material are used to measure fast electrons’ energy distribution in matter. In the Compton X-ray spectrometer, X-rays are converted into recoil electrons by Compton scattering in a converter made from fused silica glass, and a magnet-based electron energy analyzer is used to measure the energy distribution of the electrons that recoil in the direction of the incident X-rays. The spectrum of the incident X-rays is reconstructed from the energy distribution of the recoil electrons. The accuracy of this spectrometer is evaluated using a quasi-monoenergetic 6 MeV electron bunch that emanates from a linear accelerator. An electron bunch is injected into a 1.5 mm thick tungsten plate to produce bremsstrahlung X-rays. The spectrum of these bremsstrahlung X-rays is obtained in the range from 1 to 9 MeV. The energy of the electrons in the bunch is estimated using a Monte Carlo simulation of particle-matter interactions. The result shows that the spectrometer's energy accuracy is ±0.5 MeV for 6.0 MeV electrons.

  2. Properties and Applications of Laser Generated X-Ray Sources

    SciTech Connect

    Smith, R F; Key, M H

    2002-02-25

    The rapid development of laser technology and related progress in research using lasers is shifting the boundaries where laser based sources are preferred over other light sources particularly in the XUV and x-ray spectral region. Laser based sources have exceptional capability for short pulse and high brightness and with improvements in high repetition rate pulsed operation, such sources are also becoming more interesting for their average power capability. This study presents an evaluation of the current capabilities and near term future potential of laser based light sources and summarizes, for the purpose of comparison, the characteristics and near term prospects of sources based on synchrotron radiation and free electron lasers. Conclusions are drawn on areas where the development of laser based sources is most promising and competitive in terms of applications potential.

  3. Two-chicane compressed harmonic generation of soft x rays

    NASA Astrophysics Data System (ADS)

    Ratner, Daniel; Chao, Alex; Huang, Zhirong

    2011-02-01

    Seeding an electron bunch prior to compression simultaneously shifts the laser modulation to shorter wavelengths while decreasing the required modulation amplitude. The final x-ray wavelength is then tunable by controlling the compression factor with the rf phase. In this paper we describe a two-chicane scheme that allows for large modulation amplitudes, extending the method to photocathode beams with significant uncorrelated energy spreads. The downside of such compressed seeding is the need to maintain bunching across an extended accelerator region. We present analytical estimates and computer simulations to study tolerances for a sample lattice. We also note that transportation of the fine compressed modulation structure is helped by error self-correction in the second chicane, an effect that may be of more general interest.

  4. Laboratory Astrophysics with High Power Lasers and 4th Generation Light Sources

    NASA Astrophysics Data System (ADS)

    Gregori, Gianluca

    2013-10-01

    The combination of high power optical lasers and free electron lasers operating at short wavelength (in the x-ray regime) has opened new avenues for laboratory astrophysics, where exotic states of matter can now be generated and probed with high accuracy. We will review a few examples of recent experiments performed at the Linac Coherent Light Source (LCLS) free electron laser operating in Stanford (CA), but also discuss future applications. We will focus our discussion on the following three examples: 1) Laboratory analogues of white dwarf envelopes and the physics of strongly coupled plasmas near crystallization; 2) scaled laboratory experiments to investigate magnetized and radiative shocks; and 3) possible proposals for testing strong gravity analogues using x-ray Thomson scattering. This work was partially the European Research Council under the European Community's Seventh Framework Programme.

  5. Demonstration of enhanced K-edge angiography utilizing a samarium x-ray generator

    NASA Astrophysics Data System (ADS)

    Sato, Eiichi; Tanaka, Etsuro; Mori, Hidezo; Kawai, Toshiaki; Inoue, Takashi; Ogawa, Akira; Izumisawa, Mitsuru; Takahashi, Kiyomi; Sato, Shigehiro; Ichimaru, Toshio; Takayama, Kazuyoshi

    2006-08-01

    The samarium-target x-ray tube is useful in order to perform cone-beam K-edge angiography because K-series characteristic x-rays from the samarium target are absorbed effectively by iodine-based contrast media. This generator consists of the following components: a constant high-voltage power supply, a filament power supply, a turbomolecular pump, and an x-ray tube. The x-ray tube is a demountable diode which is connected to the turbomolecular pump and consists of the following major devices: a samarium target, a tungsten hairpin cathode (filament), a focusing (Wehnelt) electrode, a polyethylene terephthalate x-ray window 0.25 mm in thickness, and a stainless-steel tube body. In the x-ray tube, the positive high voltage is applied to the anode (target) electrode, and the cathode is connected to the tube body (ground potential). In this experiment, the tube voltage applied was from 50 to 70 kV, and the tube current was regulated to within 0.10 mA by the filament temperature. The exposure time is controlled in order to obtain optimum x-ray intensity. The electron beams from the cathode are converged to the target by the focusing electrode, and bremsstrahlung x-rays were absorbed using a 50-µm-thick tungsten filter. The x-ray intensity was 1.04 μGy/s at 1.0 m from the x-ray source with a tube voltage of 60 kV and a tube current of 0.10 mA, and angiography was performed using a computed radiography system and iodine-based microspheres 15 µm in diameter. In angiography of non-living animals, we observed fine blood vessels of approximately 100 µm with high contrasts.

  6. Femtosecond electron and x-ray generation by laser andplasma-based sources

    SciTech Connect

    Esarey, E.; Leemans, W.P.

    2000-02-01

    The generation of ultra-short x-rays by Thomson scattering intense laser pulses from electron beams is discussed, including recent experimental results and methods for enhancing the x-ray flux. A high flux of x-rays in a femtosecond pulse requires the generation of femtosecond electron bunches and a head-on Thomson scattering geometry. The generation of ultrashort electron bunches in a plasma-based accelerator with an injection technique that uses two colliding laser pulses is discussed. Simulations indicate the bunches as short as a few fs can be produced. Conversion of the fs electron pulse to a fs x-ray pulse can be accomplished by Bremsstrahlung or Thomson scattering.

  7. Status of the parametric X-ray generator at LEBRA, Nihon University

    NASA Astrophysics Data System (ADS)

    Hayakawa, Y.; Sato, I.; Hayakawa, K.; Tanaka, T.; Mori, A.; Kuwada, T.; Sakai, T.; Nogami, K.; Nakao, K.; Sakae, T.

    2006-11-01

    A parametric X-ray radiation (PXR) generator system was constructed in 2001 in a dedicated beamline connected to the 125 MeV electron linac of the Laboratory for Electron Beam Research and Application at Nihon University. This generator system consists of two perfect-silicon-crystal plates mounted on precisely moving mechanical setup to achieve a wide tunability. The experimental operation of the PXR generator started early in 2004; X-rays were first observed through this device in April 2004. Application studies using the PXR beam from a 100 MeV electron beam have been conducted since July 2004. Preliminary results suggest the possibility of applying the PXR to advanced X-ray imaging and to the measurement of X-ray absorption fine structure.

  8. Wire array z-pinch insights for high x-ray power generation

    SciTech Connect

    Sanford, T.W.L.; Mock, R.C.; Nash, T.J.

    1998-08-01

    The discovery that the use of very large numbers of wires enables high x-ray power to be generated from wire-array z-pinches represents a breakthrough in load design for large pulsed power generators, and has permitted high temperatures to be generated in radiation cavities on Saturn. In this paper, changes in x-ray emission characteristics as a function of wire number, array mass, and load radius, for 20-mm-long aluminum arrays on Saturn that led to these breakthrough hohlraum results, are discussed and compared with a few related emission characteristics of high-wire-number aluminum and tungsten arrays on Z. X=ray measurement comparisons with analytic models and 2-D radiation-magnetohydrodynamic (RMHC) code simulations in the x-y and r-z planes provide confidence in the ability of the models and codes to predict future x-ray performance with very-large-number wire arrays.

  9. Wire array z-pinch insights for high x-ray power generation

    SciTech Connect

    Sanford, T.W.L.; Mock, R.C.; Marder, B.M.

    1997-12-31

    The discovery that the use of very large numbers of wires enables high x-ray power to be generated from wire-array z-pinches represents a breakthrough in load design for large pulsed power generators, and has permitted high temperatures to be generated in radiation cavities on Saturn and Z. In this paper, changes in x-ray emission characteristics as a function of wire number, array mass, and load radius, for 20-mm-long aluminum arrays on Saturn that led to these breakthrough hohlraum results, are discussed and compared with a few related emission characteristics of high-wire-number aluminum and tungsten arrays on Z. X-ray measurement comparisons with analytic models and 2-D radiation-magnetohydrodynamic (RMHC) code simulations in the x-y and r-z planes provide confidence in the ability of the models and codes to predict future x-ray performance with very-large-number wire arrays.

  10. Titanium dioxide nanofiber-cotton targets for efficient multi-keV x-ray generation

    SciTech Connect

    Tanabe, Minoru; Nishimura, Hiroaki; Fujioka, Shinsuke; Nagai, Keiji; Yamamoto, Norimasa; Mima, Kunioki; Gu, Zhong-Ze; Pan, Chao; Girard, Frederic; Primout, Michel; Villette, Bruno; Brebion, Didier; Fournier, Kevin B.; Fujishima, Akira

    2008-08-04

    Multi-keV x-ray generation from low-density (27{+-}7 mg/cm{sup 3}) nanofiber-cotton targets composed of titanium dioxide has been investigated. The cotton targets were heated volumetrically and supersonically to a peak electron temperature of 2.3 keV, which is optimal to yield Ti K-shell x rays. Considerable enhancement of conversion efficiency [(3.7{+-}0.5)%] from incident laser energy into Ti K-shell x rays (4-6 keV band) was attained in comparison with that [(1.4{+-}0.9)%] for a planar Ti-foil target.

  11. Tunable narrow-photon-energy X-ray generator utilizing a tungsten-target tube

    NASA Astrophysics Data System (ADS)

    Sato, Eiichi; Sugiyama, Hiroshi; Ando, Masami; Tanaka, Etsuro; Mori, Hidezo; Kawai, Toshiaki; Inoue, Takashi; Ogawa, Akira; Takayama, Kazuyoshi; Onagawa, Jun; Ido, Hideaki

    2006-11-01

    A preliminary experiment for producing narrow-photon-energy cone-beam X-rays using a silicon single crystal is described. In order to produce low-photon-energy X-rays, a 100-μm-focus X-ray generator in conjunction with a (1 1 1) plane silicon crystal is employed. The X-ray generator consists of a main controller and a unit with a high-voltage circuit and a microfocus X-ray tube. The maximum tube voltage and current were 35 kV and 0.50 mA, respectively, and the X-ray intensity of the microfocus generator was 48.3 μGy/s at 1.0 m from the source with a tube voltage of 30 kV and a current of 0.50 mA. The effective photon energy is determined by Bragg's angle, and the photon-energy width is regulated by the angle delta. Using this generator in conjunction with a computed radiography system, quasi-monochromatic radiography was performed using a cone beam with an effective energy of approximately 17 keV.

  12. Generation of soft X rays in a vircator with exploding anode foil

    NASA Astrophysics Data System (ADS)

    Dubinov, A. E.; Efimova, I. A.; Kargin, V. I.; Ryaslov, E. A.; Selemir, V. D.

    2007-06-01

    A soft X-ray generator is designed on the basis of a vircator the plasma anode of which is formed by electrical explosion of anode foil. The intensity of soft X-ray radiation (E γ > 20 eV) produced by vircators with a metal and plasma anode is measured. Microwave pulses indicating the presence of a virtual cathode in the plasma beam are detected.

  13. Characteristics of the low photon energy plasma x-ray generator

    NASA Astrophysics Data System (ADS)

    Sato, Eiichi; Toriyabe, Hiroyuki; Sagae, Michiaki; Hayasi, Yasuomi; Usuki, Tatsumi; Sato, Koetsu; Ido, Hideaki; Takayama, Kazuyoshi; Tamakawa, Yoshiharu

    2001-12-01

    The tentative experiment for production low photon energy characteristic x-rays using a capillary is described. The capillary of this flash x-ray tube was improved in order to increase the x-ray intensity and to generate high-intensity characteristic x-rays by forming the linear plasma x-ray source. The generator consists of a high-voltage power supply, a polarity-inversion ignitron pulse generator, a turbo-molecular pump, and a radiation tube with a capillary. A high-voltage condenser of 0.2(mu) F in the pulse generator is charged up to 20 kV by the power supply, and the electric charges in the condenser are discharged to the capillary in the tube after closing the ignitron. In the present work, the pump evacuates air from the tube with a pressure of about 1 mPa, and the aluminum anode and cathode electrodes are employed to produce characteristic x-rays. The diameter and the length of the capillary are 2.0 and 29 mm, respectively, and both the cathode voltage and the discharge current displayed almost the damped oscillations. The peak values of the voltage and current increased when the charging voltage was increase, and their maximum values were -9.2 kV and 4.6 kA, respectively. The x-ray durations detected by a 1.6 micrometers aluminum filter were less than 10microsecond(s) , and we observe the intensity of aluminum characteristic x-rays.

  14. Characteristics of the plasma flash x-ray generator and applications

    NASA Astrophysics Data System (ADS)

    Sato, Eiichi; Sagae, Michiaki; Ichimaru, Toshio; Takahashi, Kei; Ojima, Hidenori; Takayama, Kazuyoshi; Hayasi, Yasuomi; Ido, Hideaki; Sakamaki, Kimio; Tamakawa, Yoshiharu

    1999-06-01

    Various characteristics of a plasma flash x-ray generator having a cold-cathode radiation tube and its application to high-speed soft radiography are described. The x-ray generator employs a high-voltage power supply, a low-impedance coaxial transmission line with a gap switch, a high-voltage condenser with a capacity of about 200 nF, a turbo-molecular pump, a thyristor pulser as a trigger device, and a flash x-ray tube. The high-voltage main condenser is charged up to 60 kV by the power supply, and the electric charges in the condenser are discharged to the tube after triggering the cathode electrode. The flash x-rays are then produced. The x-ray tube is of a demountable triode which is connected to the turbo molecular pump with a pressure of approximately 1 mPa. As the electron flows from the cathode electrode are roughly converged to the target by the electric field in the tube, the plasma x-ray source which consists of metal ions and electrons is produced by the target evaporating. Both the tube voltage and current displayed damped oscillations, and their peak values increased according to increases in the charging voltage. In the present work, the peak tube voltage was almost equivalent to the initial charging voltage of the main condenser, and the peak current was less than 30 kA. In this experiment, we employed four types of plasma targets as follows: (1) single target, (2) coaxial double target, (3) alloy target, and (4) plate target. When the single target in conjunction with the monochromatic filter was employed, high-intensity quasi- monochromatic x-rays were obtained. Next, the characteristic x-ray intensities from the outer target increased in the case where the double target was used. By using the alloy (copper tungsten) target, the x-ray intensities of the copper K-series lines increased. Finally, when the linear plasma x-ray source was formed by using the plate target, the bremsstrahlung x- rays were absorbed and were converted into florescent rays

  15. Generation Mechanisms UV and X-ray Emissions During SL9 Impact

    NASA Technical Reports Server (NTRS)

    Waite, J. Hunter, Jr.

    1997-01-01

    The purpose of this grant was to study the ultraviolet and X-ray emissions associated with the impact of comet Shoemaker-Levy 9 with Jupiter. The University of Michigan task was primarily focused on theoretical calculations. The NAGW-4788 subtask was to be largely devoted to determining the constraints placed by the X-ray observations on the physical mechanisms responsible for the generation of the X-rays. Author summarized below the ROSAT observations and suggest a physical mechanism that can plausibly account for the observed emissions. It is hoped that the full set of activities can be completed at a later date. Further analysis of the ROSAT data acquired at the time of the impact was necessary to define the observational constraints on the magnetospheric-ionospheric processes involved in the excitation of the X-ray emissions associated with the fragment impacts. This analysis centered around improvements in the pointing accuracy and improvements in the timing information. Additional pointing information was made possible by the identification of the optical counterparts to the X-ray sources in the ROSAT field-of-view. Due to the large number of worldwide observers of the impacts, a serendipitous visible plate image from an observer in Venezuela provided a very accurate location of the present position of the X-ray source, virtually eliminating pointing errors in the data. Once refined, the pointing indicated that the two observed X-ray brightenings that were highly correlated in time with the K and P2 events were brightenings of the X-ray aurora (as identified in images prior to the impact).Appendix A "ROSAT observations of X-ray emissions from Jupiter during the impact of comet Shoemaker-Levy 9' also included.

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

    SciTech Connect

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

    2011-03-21

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

  17. Resonant photo-pumping x-ray-laser scheme using intense characteristic x rays for water-window radiation generation

    SciTech Connect

    Kawachi, Tetsuya; Kato, Yoshiaki

    2011-12-15

    A line pair for a resonant photo-pumping x-ray-laser scheme is proposed in which the wavelength matching between the aluminum K{alpha}{sub 2} line ({lambda}= 0.833 95 nm) and the 2p{sup 6}-(2p{sub 1/2},4d{sub 3/2}){sub 1} transition of the neonlike zinc ions ({lambda}= 0.834 00 nm) is used. The population kinetics code of the neonlike zinc ions in plasma under irradiation of the aluminum K{alpha} line shows that substantial amplification gain can be generated in the transition of (2p{sub 1/2},3p{sub 1/2}){sub 0}-(2p{sub 1/2},4d{sub 3/2}){sub 1} at a wavelength of 3.5 nm. We also investigate the experimental arrangement of this scheme, which implies that this scheme is feasible with the present ultra-short-pulse-laser technology.

  18. High-harmonic generation and parametric amplification in the soft X-rays from extended electron trajectories

    PubMed Central

    Seres, J.; Seres, E.; Landgraf, B.; Ecker, B.; Aurand, B.; Kuehl, T.; Spielmann, C.

    2014-01-01

    We report, for the first time, the generation of high-order harmonics in a spectral range between 200 eV and 1 keV with an unusual spectral property: only every 4th (4i + 1, i∈ℵ) harmonic line appears, whereas the usual high-harmonic spectra consist of every odd (2i + 1) harmonic. We attribute this unique property to the quantum path interference of two extended electron trajectories that experience multiple re-scattering. In the well-established theory, electrons emitted via tunnel ionisation are accelerated by a laser field, return to the ion and recombine. The acceleration typically lasts for less than one optical cycle, and the electrons radiate in the extreme ultraviolet range at recombination. In contrast, for extended trajectories, electrons are accelerated over two or more optical cycles. Here, we demonstrate that two sets of trajectories dominate and provide substantial contributions to the generated soft X-ray radiation because they fulfil the resonance condition for X-ray parametric amplification. PMID:24577220

  19. Quasi-monochromatic radiography using a high-intensity quasi-x-ray laser generator

    NASA Astrophysics Data System (ADS)

    Sato, Eiichi; Hayasi, Yasuomi; Tanaka, Etsuro; Mori, Hidezo; Kawai, Toshiaki; Usuki, Tatsumi; Sato, Koetsu; Obara, Haruo; Ichimaru, Toshio; Takayama, Kazuyoshi; Ido, Hideaki; Tamakawa, Yoshiharu

    2002-05-01

    High-intensity quasi-monochromatic x-ray irradiation from the linear plasma target is described. The plasma x-ray generator employs a high-voltage power supply, a low- impedance coaxial transmission line, a high-voltage condenser with a capacity of about 200 nF, a turbo-molecular pump, a thyristor pulse generator as a trigger device, and a flash x-ray tube. The high-voltage main condenser is charged up to 55 kV by the power supply, and the electric charges in the condenser are discharged to the tube after triggering the cathode electrode. The flash x-rays are then produced. The x-ray tube is of a demountable triode that is connected to the turbo molecular pump with a pressure of approximately 1 mPa. As the electron flows from the cathode electrode are roughly converged to the molybdenum target by the electric field in the tube, the plasma x-ray source, which consists of metal ions and electrons, forms by the target evaporating. Both the tube voltage and current displayed damped oscillations, and their peak values increased according to increases in the charging voltage. In the present work, the peak tube voltage was almost equal to the initial charging voltage of the main condenser, and the peak current was about 20 kA with a charging voltage of 55 kV. When the charging voltage was increased, the linear plasma x-ray source formed, and the characteristic x-ray intensities of K-series lines increased. The quasi- monochromatic radiography was performed by as new film-less computed radiography system.

  20. Soft x-ray generation in gases with an ultrashort pulse laser

    SciTech Connect

    Ditmire, T R

    1996-01-08

    An experimental investigation of soft x-ray production resulting from the interaction of intense near infra-red laser radiation with gases is presented in this thesis. Specifically, soft x-ray generation through high order harmonic generation or exploiting intense inverse bremsstrahlung heating is examined. Most of these studies are conducted with femtosecond, terawatt class Cr:LiSrAlF{sub 6} (LiSAF) laser, though results derived from studies with other laser systems are presented as well. The majority of this work is devoted to experimental investigations, however, theoretical and computational models are developed to interpret the data. These studies are motivated by the possibility of utilizing the physics of intense laser/matter interactions as a potential compact source of bright x-rays. Consequently, the thrust of many of the experiments conducted is aimed at characterizing the x-rays produced for possible use in applications. In general, the studies of this manuscript fall into three categories. First, a unique 130 fs, 8 TW laser that is based on chirped pulse amplification, is described, and its performance is evaluated. The generation of x-rays through high order harmonics is then discussed with emphasis on characterizing and optimizing harmonic generation. Finally, the generation of strong, incoherent x-ray radiation by the intense irradiation of large (>1,000 atom) clusters in gas jets, is explored. The physics of laser energy absorption by clusters illuminated with intensities of 10{sup 15} to 10{sup 17} W/cm{sup 2} is considered in detail. X-ray spectroscopy of the hot plasmas that result from the irradiation of the clusters is conducted, and energy transport and kinetics issues in these plasmas are discussed.

  1. Tentative experiment for generating low-photon-energy quasi-x-ray lasers using a capillary

    NASA Astrophysics Data System (ADS)

    Sato, Eiichi; Toriyabe, Hiroyuki; Awaji, Wataru; Hayasi, Yasuomi; Ichimaru, Toshio; Usuki, Tatsumi; Sato, Koetsu; Ojima, Hidenori; Takayama, Kazuyoshi; Tamakawa, Yoshiharu

    2001-04-01

    The tentative experiment for producing low-photon-energy quasi-x-ray laser using a capillary is described. This flash x-ray generator was improved in order to increase the x-ray intensity and to produce high-intensity characteristic x-rays by forming the linear plasma x-ray source. The generator consists of a high-voltage power supply, a polarity-inversion ignitron pulse generator, a turbo-molecular pump, and a radiation tube with a capillary. A high-voltage condenser of 0.2 (mu) F in the pulse generator is charged up to 20 kV by the power supply, and the electric charges in the condenser are discharged to the capillary in the tube after closing the ignitron. In the present work, the chamber is evacuated by the pump with a pressure of about 1 mPa, and the carbon anode and cathode electrodes are employed to produce K(alpha) characteristic x-rays. The diameter and the length of the ferrite capillary are 2.0 and 29 mm, respectively, and both the cathode voltage and the discharge current displayed damped oscillations. The peak values of the voltage and current increased when the charging voltage was increased, and their maximum values were -9.9 kV and 4.4 kA, respectively. The pulse durations of the x-rays were nearly equivalent to those of the damped oscillations in the voltage and current, and their values were less than 20 microseconds. In the spectrum measurement, we observed the carbon K(alpha) line.

  2. Development of all-solid-state flash x-ray generator with photoconductive semiconductor switches

    NASA Astrophysics Data System (ADS)

    Xun, Ma; Jianjun, Deng; Hongwei, Liu; Jianqiang, Yuan; Jinfeng, Liu; Bing, Wei; Yanling, Qing; Wenhui, Han; Lingyun, Wang; Pin, Jiang; Hongtao, Li

    2014-09-01

    A compact, low-jitter, and high repetitive rate all-solid-state flash x-ray generator making use of photo conductive semiconductor switches was developed recently for the diagnostic purpose of some hydrokinetical experiments. The generator consisted of twelve stages of Blumlein pulse forming networks, and an industrial cold cathode diode was used to generate intense x-ray radiations with photon energy up to 220 keV. Test experiments showed that the generator could produce >1 kA electron beam currents and x-ray pulses with ˜40 ns duration under 100 Hz repetitive rates at least (limited by the triggering laser on hand), also found was that the delay time of the cathode explosive emission is crucial to the energy transfer efficiency of the whole system. In addition, factors affecting the diode impedance, how the switching synchronization and diode impedance determining the allowable operation voltage were discussed.

  3. Development of all-solid-state flash x-ray generator with photoconductive semiconductor switches.

    PubMed

    Xun, Ma; Jianjun, Deng; Hongwei, Liu; Jianqiang, Yuan; Jinfeng, Liu; Bing, Wei; Yanling, Qing; Wenhui, Han; Lingyun, Wang; Pin, Jiang; Hongtao, Li

    2014-09-01

    A compact, low-jitter, and high repetitive rate all-solid-state flash x-ray generator making use of photo conductive semiconductor switches was developed recently for the diagnostic purpose of some hydrokinetical experiments. The generator consisted of twelve stages of Blumlein pulse forming networks, and an industrial cold cathode diode was used to generate intense x-ray radiations with photon energy up to 220 keV. Test experiments showed that the generator could produce >1 kA electron beam currents and x-ray pulses with ~40 ns duration under 100 Hz repetitive rates at least (limited by the triggering laser on hand), also found was that the delay time of the cathode explosive emission is crucial to the energy transfer efficiency of the whole system. In addition, factors affecting the diode impedance, how the switching synchronization and diode impedance determining the allowable operation voltage were discussed. PMID:25273719

  4. Development of all-solid-state flash x-ray generator with photoconductive semiconductor switches

    SciTech Connect

    Xun, Ma; Jianjun, Deng; Hongwei, Liu; Jianqiang, Yuan; Jinfeng, Liu; Bing, Wei; Yanling, Qing; Wenhui, Han; Lingyun, Wang; Pin, Jiang; Hongtao, Li

    2014-09-15

    A compact, low-jitter, and high repetitive rate all-solid-state flash x-ray generator making use of photo conductive semiconductor switches was developed recently for the diagnostic purpose of some hydrokinetical experiments. The generator consisted of twelve stages of Blumlein pulse forming networks, and an industrial cold cathode diode was used to generate intense x-ray radiations with photon energy up to 220 keV. Test experiments showed that the generator could produce >1 kA electron beam currents and x-ray pulses with ∼40 ns duration under 100 Hz repetitive rates at least (limited by the triggering laser on hand), also found was that the delay time of the cathode explosive emission is crucial to the energy transfer efficiency of the whole system. In addition, factors affecting the diode impedance, how the switching synchronization and diode impedance determining the allowable operation voltage were discussed.

  5. Super-characteristic x-ray generator utilizing a pipe and rod target

    NASA Astrophysics Data System (ADS)

    Sato, Eiichi; Tanaka, Etsuro; Mori, Hidezo; Kawai, Toshiaki; Inoue, Takashi; Ogawa, Akira; Izumisawa, Mitsuru; Takahashi, Kiyomi; Sato, Shigehiro; Ichimaru, Toshio; Takayama, Kazuyoshi

    2006-08-01

    This generator consists of the following components: a constant high-voltage power supply, a filament power supply, a turbomolecular pump, and an x-ray tube. The x-ray tube is a demountable diode which is connected to the turbomolecular pump and consists of the following major devices: a tungsten hairpin cathode (filament), a focusing (Wehnelt) electrode, a polyethylene terephthalate x-ray window 0.25 mm in thickness, a stainless-steel tube body, a pipe target, and a rod target. The pipe and rod targets are useful for forming linear and cone beams, respectively. In the x-ray tube, the positive high voltage is applied to the anode (target) electrode, and the cathode is connected to the tube body (ground potential). In this experiment, the tube voltage applied was from12 to 20 kV, and the tube current was regulated to within 0.10 mA by the filament temperature. The exposure time is controlled in order to obtain optimum x-ray intensity. The electron beams from the cathode are converged to the target by the focusing electrode, and clean K-series characteristic x-rays are produced through the focusing electrode without using a filter. The x-ray intensities of the pipe and rod targets were 1.29 and 4.28 μGy/s at 1.0 m from the x-ray source with a tube voltage of 15 kV and a tube current of 0.10 mA, and quasi-monochromatic radiography was performed using a computed radiography system.

  6. X-ray generation at SPARC_LAB Thomson backscattering source

    NASA Astrophysics Data System (ADS)

    Giribono, Anna

    2015-03-01

    In the last years, the phase contrast X-ray imaging became a very promising technique, in particular for medical application. At this purpose, several compact and very performing X-ray sources are growing up all around the world and most of them are based upon the Thomson backscattering phenomenon. This is the context of the SPARC_LAB Thomson backscattering X-ray source, presently under commissioning at INFN-LNF. Here a head-on collision is foreseen at the Thomson Interaction Point between a 30 to 150MeV electron beam and the 250TW FLAME laser pulse, providing a photon energy tunability in the range from 20 to 250keV. The first experiment foresees the generation of a X-ray beam, useful for X-ray imaging of mammographic phantoms with the phase contrast technique. In February 2014, the SPARC_LAB Thomson source produced its very first X-ray beam. The shift and the obtained results are presented.

  7. A free-electron laser fourth-generation x-ray source

    SciTech Connect

    Moncton, D. E.

    1999-10-21

    The field of synchrotrons radiation research has grown rapidly over the last 25 years due to both the push of the accelerator and magnet technology that produces the x-ray beams and the pull of the extraordinary scientific research those beams make possible. Three successive generations of synchrotrons radiation facilities have resulted in beam brilliances 11 to 12 orders of magnitude greater than the standard laboratory x-ray tube. However, greater advances can be easily imagined given the fact that x-ray beams from present-day facilities do not exhibit the coherence or time structure so familiar with the.optical laser. Theoretical work over the last ten years or so has pointed to the possibility of generating hard x-ray beams with laser-like characteristics. The concept is based on self-amplified spontaneous emission in free electron lasers. The use of a superconducting linac could produce a major, cost-effective facility that spans wavelengths from the ultraviolet to the hard x-ray regime, simultaneously servicing large numbers experimenters from a wide range of disciplines. As with each past generation of synchrotron facilities, immense new scientific opportunities from fourth-generation sources.

  8. Design of a Nb3Sn Magnet for a 4th Generation ECR Ion Source

    SciTech Connect

    Prestemon, S,; Trillaud, F.; Caspi, S.; Ferracin, P.; Sabbi, G. L.; Lyneis, C. M.; Leitner, D.; Todd, D. S.; Hafalia, R.

    2008-08-17

    The next generation of Electron Cyclotron Resonant (ECR) ion sources are expected to operate at a heating radio frequency greater than 40 GHz. The existing 3rd generation systems, exemplified by the state of the art system VENUS, operate in the 10-28 GHz range, and use NbTi superconductors for the confinement coils. The magnetic field needed to confine the plasma scales with the rf frequency, resulting in peak fields on the magnets of the 4th generation system in excess of 10 T. High field superconductors such as Nb{sub 3}Sn must therefore be considered. The magnetic design of a 4th. generation ECR ion source operating at an rf frequency of 56 GHz is considered. The analysis considers both internal and external sextupole configurations, assuming commercially available Nb{sub 3}Sn material properties. Preliminary structural design issues are discussed based on the forces and margins associated with the coils in the different configurations, leading to quantitative data for the determination of a final magnet design.

  9. The ARC-EN-CIEL French 4th Generation Light Source

    SciTech Connect

    Bruni, C.; Couprie, M. E.; Chubar, O.; Loulergue, A.; Nahon, L.; Carre, B.; Garzella, D.; Labat, M.; Lambert, G.; Monot, P.; Jablonka, M.; Meot, F.; Ortega, J. M.; Nutarelli, D.

    2007-01-19

    ARC-EN-CIEL (Accelerator-Radiation Complex for Enhanced Coherent Intense Extended Light) proposal is based on a CW 1 GeV superconducting linear accelerator delivering high charge, subpicosecond, low emittance electron bunches with a high repetition rate (1 kHz). The FEL uses High Harmonics Generation in gases in a High Gain Harmonic Generation scheme, leading to a rather compact solution. The radiation extends down to 0.8 nm with the non-linear harmonics and reproduces the good longitudinal and transverse coherence of the harmonics generated in gas. Optional beam loops, foreseen to increase the beam current or the energy, will accommodate infrared CSR source, femtosecond undulator sources in the VUV and X-ray ranges, and a FEL oscillator in the 10 nm range. An important synergy is expected between accelerator and laser communities, in particular for electron plasma acceleration tests.

  10. Microwave Kinetic Inductance Detectors: Large Format X-ray Spectral Imagers for the Next Generation of X-ray Telescopes

    NASA Astrophysics Data System (ADS)

    Eckart, Megan E.; Mazin, B. A.; Bumble, B.; Golwala, S. R.; Zmuidzinas, J.; Day, P. K.; Harrison, F. A.

    2006-09-01

    Microwave Kinetic Inductance Detectors (MKIDs) have the potential to provide megapixel imagers with few eV spectral resolution for future X-ray missions such as Gen-X. MKIDs offer the advantage over many other cryogenic detector technologies that they can be easily multiplexed, so that arrays with many thousand pixels are readily achievable. In addition, the readout electronics can be operated at room temperature, a significant advantage for space applications. MKIDs exploit the dependence of surface impedance of a superconductorwith the quasiparticle density. Quasiparticles are created by absorption of X-rays, with number proportional to the X-ray energy. The impedance change may be sensitively measured using a thin-film resonant circuit. The practical application of MKIDs for photon detection requires a method of efficiently coupling the photon energy to the MKID. To apply the MKID scheme to X-ray detection we pattern tantalum strips with aluminum MKIDs attached at each end. An incident X-ray is absorbed in the Ta and creates millions of quasiparticle excitations, which diffuse to each end of the strip, finally entering the Al resonators where they are trapped and sensed. Simultaneous monitoring of the signal at both ends of the strip allow position and energy determination for each photon. We have demonstrated working strip detectors in the laboratory, and will present our measurements of the quasiparticle diffusion constant and the quasiparticle lifetime in tantalum, the aluminum quasiparticle lifetime, and the energy resolution of the detector. We will also discuss ideas for future detector designs and suggest ultimate performance goals for X-ray astronomy applications.

  11. Compton X-rays from Self-Generated Backscattered Radiation in a Laser Wakefield Accelerator

    NASA Astrophysics Data System (ADS)

    Ting, Antonio; Kaganovich, Dmitri; Helle, Michael; Chen, Yu-Hsin; Palastro, John; Hafizi, Bahman; Gordon, Daniel

    2015-11-01

    A unique Compton scattering configuration for generating monochromatic, short pulse, and potentially coherent x-rays in a Laser Wakefield Accelerator (LWFA) is being studied at the Naval Research Laboratory. Reflection mechanisms such as stimulated Raman scattering and shock-created density gradients in a plasma can generate the required backward-travelling laser pulse directly from the same laser pulse used in the LWFA, i.e., the high energy electron beam and the counter-propagating photon beam are both self-generated by an ultrashort laser pulse in plasma. Extended interaction distance and automatic alignment of electron beam and backscattered radiation could be beneficial to the amplification of the Doppler upshifted Compton X-rays. Preliminary experiments are ongoing with measurement of Raman backscattering and reflection off a plasma density gradient. Energy resolved X-ray results are also anticipated. This work is supported by NRL Base Program and DOE.

  12. U-shape rotating anti-cathode compact X-ray generator: 20 times stronger than the commercially available X-ray source

    PubMed Central

    Sakabe, N.; Sakabe, K.; Ohsawa, S.; Sakai, T.; Kobayakawa, H.; Sugimura, T.; Ikeda, M.; Tawada, M.; Watanabe, N.; Sasaki, K.; Wakatsuki, M.

    2013-01-01

    A new type of U-shape anti-cathode X-ray generator in which the inner surface of a cylindrical target is irradiated by an electron beam has been made by modifying a conventional rotating anti-cathode X-ray generator whose brightness in the catalog is 12 kW mm−2. The target material (Cu), target radius (50 mm) and rotating speed (6000 r.p.m.) were not changed in this modification. A brightness of 52 kW mm−2 was obtained by this U-shape-type X-ray generator. This means that the brightness of the new type is 4.3 times greater than that of the old unmodified one. Furthermore, the new-type X-ray generator yielded a brightness of 129 kW mm−2 by adding a carbon coating on the Cu target. This means an overall increase of brightness of ten times. The original generator has the highest brightness in the generators of the same class (having a radius of 50 mm and rotation speed of 6000 r.p.m.). Observations showed that Cu Kα counts at vertical incidence of the electron beam onto the surface of the new target, which is initially optically smooth, decrease as the surface is roughened by a severe thermal stress caused by strong electron beam exposure. Further observation reveals, however, that oblique incidence of the electron beam onto the roughened surface drastically increased the X-ray output and amounts to twice as much as that from a smooth surface at vertical incidence. Thus, at the present stage, an overall increase of brightness has been realised at a level 20 times stronger than that of the original commercially offered X-ray generator that we modified. PMID:24121322

  13. HEXITEC: A Next Generation Hard X-ray Detector for Solar Observations

    NASA Astrophysics Data System (ADS)

    Ryan, Daniel; Christe, Steven; Shih, Albert; Inglis, Andrew R.; Gregory, Kyle; Baumgartner, Wayne H.; Gaskin, Jessica; Wilson-Hodge, Colleen; Seller, Paul; Wilson, Matthew; Veale, Matthew C.; Panessa, Marco

    2016-05-01

    There is an increasing demand in solar physics for high resolution X-ray spectroscopic imaging. Such observations would present ground-breaking opportunities to study the poorly understood high energy processes in the solar corona such as solar flares, coronal heating, etc. However, such observations require a new breed of solid-state detectors sensititve to high energy X-rays with fine independent pixels to subsample the point spread function (PSF) of the X-ray optics. They must also be capable of handling very high count rates as photon fluxes from solar flares often cause pileup in current detectors. The Rutherford Appleton Laboratory (RAL) has recently developed a new Cadmium Telluride (CdTe) detector system, dubbed HEXITEC (High Energy X-ray Imaging Technology). It is an 80x80 array of 250 micron independent pixels sensitive in the 4--80 keV band and capable of a high full frame readout rate of 10 kHz. HEXITEC provides the smallest independently read out pixels currently available, and are well matched to the few arcsecond PSF produced by the current and next generation hard X-ray focusing optics. NASA's Goddard and Marshall Space Flight Centers are collaborating with RAL to develop these detectors for use on future space-borne hard X-ray focusing telescopes. In this poster we show the latest results on HEXITEC's imaging capability, high read out rate, and energy sensitivity and reveal it to be ideal for such future instruments. The potential observations obtained by combining HEXITEC with the next generation of X-ray focusing optics could to revolutionize our understanding of high energy processes in the solar corona.

  14. Generation of intense coherent soft x-ray with electron microbunches induced and frozen by lasers

    SciTech Connect

    Yu. L.H.

    1983-01-01

    We describe a new improved version of Transverse Optical Klystron Harmonic Generator that uses three lasers to replace the undulators in the modulator and radiator and freeze the electron microbunching. We show that intense soft x-rays can be generated.

  15. Characteristics of Radiation Generated with the X-ray Source NESTOR

    SciTech Connect

    Gladkikh, P.; Kovalyova, N.; Shcherbakov, A.; Zelinsky, A.

    2007-01-19

    The results of analytical calculations and numerical simulations of the basic SR characteristics, generated from bending magnets of the storage ring NESTOR and hard X-rays generated through Compton scattering of an intense laser beam by relativistic electron are presented in this work. It is shown that Compton X-ray source NESTOR which construction in NSC KIPT is supported with NATO grant number SfP-977982 covers radiation energy range from 0.3 eV till 1 MeV with photon flux of about 1010 - 1012 phot/s. The possible areas of radiation application of the storage ring NESTOR are given.

  16. Demonstration of enhanced K-edge angiography using a cerium target x-ray generator

    SciTech Connect

    Sato, Eiichi; Tanaka, Etsuro; Mori, Hidezo; Kawai, Toshiaki; Ichimaru, Toshio; Sato, Shigehiro; Takayama, Kazuyoshi; Ido, Hideaki

    2004-11-01

    The cerium target x-ray generator is useful in order to perform enhanced K-edge angiography using a cone beam because K-series characteristic x rays from the cerium target are absorbed effectively by iodine-based contrast mediums. The x-ray generator consists of a main controller, a unit with a Cockcroft-Walton circuit and a fixed anode x-ray tube, and a personal computer. The tube is a glass-enclosed diode with a cerium target and a 0.5-mm-thick beryllium window. The maximum tube voltage and current were 65 kV and 0.4 mA, respectively, and the focal-spot sizes were 1.0x1.3 mm. Cerium K{alpha} lines were left using a barium sulfate filter, and the x-ray intensity was 0.48 {mu}C/kg at 1.0 m from the source with a tube voltage of 60 kV, a current of 0.40 mA, and an exposure time of 1.0 s. Angiography was performed with a computed radiography system using iodine-based microspheres. In coronary angiography of nonliving animals, we observed fine blood vessels of approximately 100 {mu}m with high contrasts.

  17. Generation and application of the soft X-ray laser beam based on capillary discharge

    NASA Astrophysics Data System (ADS)

    Frolov, Oleksandr; Kolacek, Karel; Straus, Jaroslav; Schmidt, Jiri; Prukner, Vaclav; Shukurov, Andrey

    2014-05-01

    In this work we report on the generation and characterization of a focused soft X-ray laser beam with intensity and energy density that exceed the threshold for the ablation of PMMA. We demonstrate a feasibility of direct ablation of holes using a focused soft X-ray laser beam. Ablated craters in PMMA/gold-covered-PMMA samples were obtained by focusing the soft X-ray Ar8+ laser pulses generated by a 46.9 nm tabletop capillary-discharge-pumped driver with a spherical Si/Sc multilayer mirror. It was found that the focused beam is capable by one shot to ablate PMMA, even if the focus is significantly influenced by astigmatism. Analysis of the laser beam footprints by atomic force microscope shows that ablated holes have periodic surface structure (similarly as Laser-Induced Periodic Surface Structure) with period ~2,8 μm and with peak-to-peak depth ~5-10 nm.

  18. Short x-ray pulse generation using deflecting cavities at the Advanced Photon Source.

    SciTech Connect

    Sajaev, V.; Borland, M.; Chae, Y.-C.; Decker, G.; Dejus, R.; Emery, L.; Harkay, K.; Nassiri, A.; Shastri, S.; Waldschmidt, G.; Yang, B.; Anfinrud, P.; Dolgashev, V.; NIH; SLAC

    2007-11-11

    Storage-ring-based third-generation light sources can provide intense radiation pulses with durations as short as 100 ps. However, there is growing interest within the synchrotron radiation user community in performing experiments with much shorter X-ray pulses. Zholents et al. [Nucl. Instr. and Meth. A 425 (1999) 385] recently proposed using RF orbit deflection to generate sub-ps X-ray pulses. In this scheme, two deflecting cavities are used to deliver a longitudinally dependent vertical kick to the beam. An optical slit can then be used to slice out a short part of the radiation pulse. Implementation of this scheme is planned for one APS beamline in the near future. In this paper, we summarize our feasibility study of this method and the expected X-ray beam parameters. We find that a pulse length of less than two picoseconds can be achieved.

  19. Implosion dynamics and x-ray generation in small-diameter wire-array Z pinches

    SciTech Connect

    Ivanov, V. V.; Sotnikov, V. I.; Kindel, J. M.; Hakel, P.; Mancini, R. C.; Astanovitskiy, A. L.; Haboub, A.; Altemara, S. D.; Shevelko, A. P.; Kazakov, E. D.; Sasorov, P. V.

    2009-05-15

    It is known from experiments that the radiated x-ray energy appears to exceed the calculated implosion kinetic energy and Spitzer resistive heating [C. Deeney et al., Phys. Rev. A 44, 6762 (1991)] but possible mechanisms of the enhanced x-ray production are still being discussed. Enhanced plasma heating in small-diameter wire arrays with decreased calculated kinetic energy was investigated, and a review of experiments with cylindrical arrays of 1-16 mm in diameter on the 1 MA Zebra generator is presented in this paper. The implosion and x-ray generation in cylindrical wire arrays with different diameters were compared to find a transition from a regime where thermalization of the kinetic energy is the prevailing heating mechanism to regimes with other dominant mechanisms of plasma heating. Loads of 3-8 mm in diameter generate the highest x-ray power at the Zebra generator. The x-ray power falls in 1-2 mm loads which can be linked to the lower efficiency of plasma heating with the lack of kinetic energy. The electron temperature and density of the pinches also depend on the array diameter. In small-diameter arrays, 1-3 mm in diameter, ablating plasma accumulates in the inner volume much faster than in loads of 12-16 mm in diameter. Correlated bubblelike implosions were observed with multiframe shadowgraphy. Investigation of energy balance provides evidence for mechanisms of nonkinetic plasma heating in Z pinches. Formation and evolution of bright spots in Z pinches were studied with a time-gated pinhole camera. A comparison of x-ray images with shadowgrams shows that implosion bubbles can initiate bright spots in the pinch. Features of the implosions in small-diameter wire arrays are discussed to identify mechanisms of energy dissipation.

  20. Generation of bright isolated attosecond soft X-ray pulses driven by multicycle midinfrared lasers.

    PubMed

    Chen, Ming-Chang; Mancuso, Christopher; Hernández-García, Carlos; Dollar, Franklin; Galloway, Ben; Popmintchev, Dimitar; Huang, Pei-Chi; Walker, Barry; Plaja, Luis; Jaroń-Becker, Agnieszka A; Becker, Andreas; Murnane, Margaret M; Kapteyn, Henry C; Popmintchev, Tenio

    2014-06-10

    High harmonic generation driven by femtosecond lasers makes it possible to capture the fastest dynamics in molecules and materials. However, to date the shortest subfemtosecond (attosecond, 10(-18) s) pulses have been produced only in the extreme UV region of the spectrum below 100 eV, which limits the range of materials and molecular systems that can be explored. Here we experimentally demonstrate a remarkable convergence of physics: when midinfrared lasers are used to drive high harmonic generation, the conditions for optimal bright, soft X-ray generation naturally coincide with the generation of isolated attosecond pulses. The temporal window over which phase matching occurs shrinks rapidly with increasing driving laser wavelength, to the extent that bright isolated attosecond pulses are the norm for 2-µm driving lasers. Harnessing this realization, we experimentally demonstrate the generation of isolated soft X-ray attosecond pulses at photon energies up to 180 eV for the first time, to our knowledge, with a transform limit of 35 attoseconds (as), and a predicted linear chirp of 300 as. Most surprisingly, advanced theory shows that in contrast with as pulse generation in the extreme UV, long-duration, 10-cycle, driving laser pulses are required to generate isolated soft X-ray bursts efficiently, to mitigate group velocity walk-off between the laser and the X-ray fields that otherwise limit the conversion efficiency. Our work demonstrates a clear and straightforward approach for robustly generating bright isolated attosecond pulses of electromagnetic radiation throughout the soft X-ray region of the spectrum. PMID:24850866

  1. Generation of bright isolated attosecond soft X-ray pulses driven by multicycle midinfrared lasers

    PubMed Central

    Chen, Ming-Chang; Mancuso, Christopher; Hernández-García, Carlos; Dollar, Franklin; Galloway, Ben; Popmintchev, Dimitar; Huang, Pei-Chi; Walker, Barry; Plaja, Luis; Jaroń-Becker, Agnieszka A.; Becker, Andreas; Murnane, Margaret M.; Kapteyn, Henry C.; Popmintchev, Tenio

    2014-01-01

    High harmonic generation driven by femtosecond lasers makes it possible to capture the fastest dynamics in molecules and materials. However, to date the shortest subfemtosecond (attosecond, 10−18 s) pulses have been produced only in the extreme UV region of the spectrum below 100 eV, which limits the range of materials and molecular systems that can be explored. Here we experimentally demonstrate a remarkable convergence of physics: when midinfrared lasers are used to drive high harmonic generation, the conditions for optimal bright, soft X-ray generation naturally coincide with the generation of isolated attosecond pulses. The temporal window over which phase matching occurs shrinks rapidly with increasing driving laser wavelength, to the extent that bright isolated attosecond pulses are the norm for 2-µm driving lasers. Harnessing this realization, we experimentally demonstrate the generation of isolated soft X-ray attosecond pulses at photon energies up to 180 eV for the first time, to our knowledge, with a transform limit of 35 attoseconds (as), and a predicted linear chirp of 300 as. Most surprisingly, advanced theory shows that in contrast with as pulse generation in the extreme UV, long-duration, 10-cycle, driving laser pulses are required to generate isolated soft X-ray bursts efficiently, to mitigate group velocity walk-off between the laser and the X-ray fields that otherwise limit the conversion efficiency. Our work demonstrates a clear and straightforward approach for robustly generating bright isolated attosecond pulses of electromagnetic radiation throughout the soft X-ray region of the spectrum. PMID:24850866

  2. Generation and dose distribution measurement of flash x-ray in KALI-5000 system

    SciTech Connect

    Menon, Rakhee; Roy, Amitava; Mitra, S.; Sharma, A.; Mondal, J.; Mittal, K. C.; Nagesh, K. V.; Chakravarthy, D. P.

    2008-10-15

    Flash x-ray generation studies have been carried out in KALI-5000 Pulse power system. The intense relativistic electron beam has been bombarded on a tantalum target at anode to produce flash x-ray via bremsstrahlung conversion. The typical electron beam parameter was 360 kV, 18 kA, and 100 ns, with a few hundreds of A/cm{sup 2} current density. The x-ray dose has been measured with calcium sulfate:dysposium (CaSO{sub 4}:Dy) thermoluminescent dosimeter and the axial dose distribution has been characterized. It has been observed that the on axis dose falls of with distance {approx}1/x{sup n}, where n varies from 1.8 to 1.85. A maximum on axis dose of 46 mrad has been measured at 1 m distance from the source. A plastic scintillator with optical fiber coupled to a photomultiplier tube has been developed to measure the x-ray pulse width. The typical x-ray pulse width varied from 50 to 80 ns.

  3. Generation and dose distribution measurement of flash x-ray in KALI-5000 system.

    PubMed

    Menon, Rakhee; Roy, Amitava; Mitra, S; Sharma, A; Mondal, J; Mittal, K C; Nagesh, K V; Chakravarthy, D P

    2008-10-01

    Flash x-ray generation studies have been carried out in KALI-5000 Pulse power system. The intense relativistic electron beam has been bombarded on a tantalum target at anode to produce flash x-ray via bremsstrahlung conversion. The typical electron beam parameter was 360 kV, 18 kA, and 100 ns, with a few hundreds of A/cm(2) current density. The x-ray dose has been measured with calcium sulfate:dysposium (CaSO(4):Dy) thermoluminescent dosimeter and the axial dose distribution has been characterized. It has been observed that the on axis dose falls of with distance approximately 1/x(n), where n varies from 1.8 to 1.85. A maximum on axis dose of 46 mrad has been measured at 1 m distance from the source. A plastic scintillator with optical fiber coupled to a photomultiplier tube has been developed to measure the x-ray pulse width. The typical x-ray pulse width varied from 50 to 80 ns. PMID:19044706

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

    SciTech Connect

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

    2015-03-31

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

  5. Inflow Generated X-ray Corona Around Supermassive Black Holes and Unified Model for X-ray Emission

    NASA Astrophysics Data System (ADS)

    Wang, Lile; Cen, Renyue

    2016-01-01

    Three-dimensional hydrodynamic simulations, covering the spatial domain from hundreds of Schwarzschild radii to 2 pc around the central supermassive black hole of mass 108 M⊙, with detailed radiative cooling processes, are performed. Generically found is the existence of a significant amount of shock heated, high temperature (≥108 K) coronal gas in the inner (≤104 rsch) region. It is shown that the composite bremsstrahlung emission spectrum due to coronal gas of various temperatures are in reasonable agreement with the overall ensemble spectrum of AGNs and hard X-ray background. Taking into account inverse Compton processes, in the context of the simulation-produced coronal gas, our model can readily account for the wide variety of AGN spectral shape, which can now be understood physically. The distinguishing feature of our model is that X-ray coronal gas is, for the first time, an integral part of the inflow gas and its observable characteristics are physically coupled to the concomitant inflow gas. One natural prediction of our model is the anti-correlation between accretion disk luminosity and spectral hardness: as the luminosity of SMBH accretion disk decreases, the hard X-ray luminosity increases relative to the UV/optical luminosity.

  6. Inflow Generated X-Ray Corona around Supermassive Black Holes and a Unified Model for X-Ray Emission

    NASA Astrophysics Data System (ADS)

    Wang, Lile; Cen, Renyue

    2016-02-01

    Three-dimensional hydrodynamic simulations are performed, which cover the spatial domain from hundreds of Schwarzschild radii to 2 pc around the central supermassive black hole of mass {10}8{M}⊙ , with detailed radiative cooling processes. The existence of a significant amount of shock heated, high temperature (≥slant {10}8 {{K}}) coronal gas in the inner (≤slant {10}4{r}{sch}) region is generally found. It is shown that the composite bremsstrahlung emission spectrum due to coronal gas of various temperatures is in reasonable agreement with the overall ensemble spectrum of active galactic nuclei (AGNs) and hard X-ray background. Taking into account inverse Compton processes, in the context of the simulation-produced coronal gas, our model can readily account for the wide variety of AGN spectral shapes, which can now be understood physically. The distinguishing feature of our model is that X-ray coronal gas is, for the first time, an integral part of the inflow gas and its observable characteristics are physically coupled to the concomitant inflow gas. One natural prediction of our model is the anti-correlation between accretion disk luminosity and spectral hardness: as the luminosity of SMBH accretion disk decreases, the hard X-ray luminosity increases relative to the UV/optical luminosity.

  7. A practical method to generate brilliant hard x-rays with a tabletop electron storage ring

    SciTech Connect

    Yamada, H.; Amano, D.; Miyade, H.

    1995-12-31

    With electron storage rings not only synchrotron radiation(SR) but also bremsstrahlung(BS) from a thin target placed in the electron orbit are mechanisms to generate brilliant x-ray beams. The calculated brilliance of BS with a 50 MeV storage ring, which is nearly 10{sup 13} photons/s, mrad{sup 2}, mm{sup 2}, 0.1% band width for 100 keV x-rays, exceeds that of SR from a 1 GeV storage ring. This photon energy spectrum is almost constant and extend up to the electron energy. The reasons for this high brilliance with this new radiation scheme is that the electron beams penetrating the thin target are utilized repeatedly, the narrow angular divergence of BS is determined by the kinematics of relativistic electron as same as SR, and the x-ray source size of the order of 1 {mu}m is determined by the size of thin target instead of electron beam sizes. Continuous injection of electron beam to the storage ring at full energy is the way to keep high and constant beam current. Peak current and repetition rate determine x-ray out put power. Note that the power of x-ray beam is also provided from a RF cavity of the storage ring. In this paper we will report some experimental results and discuss further application on a coherent bremsstrahlung generated from a set of stacked foils placed in the electron orbit of the ring. Resulting from these investigations the photon storage ring which is based on a 50 MeV exact circular electron storage ring could provide wide range of coherent and incoherent radiations from far infrared to hard x-ray in a practical amount of radiation power.

  8. Ultraviolet surprise: Efficient soft x-ray high-harmonic generation in multiply ionized plasmas

    NASA Astrophysics Data System (ADS)

    Popmintchev, Dimitar; Hernández-García, Carlos; Dollar, Franklin; Mancuso, Christopher; Pérez-Hernández, Jose A.; Chen, Ming-Chang; Hankla, Amelia; Gao, Xiaohui; Shim, Bonggu; Gaeta, Alexander L.; Tarazkar, Maryam; Romanov, Dmitri A.; Levis, Robert J.; Gaffney, Jim A.; Foord, Mark; Libby, Stephen B.; Jaron-Becker, Agnieszka; Becker, Andreas; Plaja, Luis; Murnane, Margaret M.; Kapteyn, Henry C.; Popmintchev, Tenio

    2015-12-01

    High-harmonic generation is a universal response of matter to strong femtosecond laser fields, coherently upconverting light to much shorter wavelengths. Optimizing the conversion of laser light into soft x-rays typically demands a trade-off between two competing factors. Because of reduced quantum diffusion of the radiating electron wave function, the emission from each species is highest when a short-wavelength ultraviolet driving laser is used. However, phase matching—the constructive addition of x-ray waves from a large number of atoms—favors longer-wavelength mid-infrared lasers. We identified a regime of high-harmonic generation driven by 40-cycle ultraviolet lasers in waveguides that can generate bright beams in the soft x-ray region of the spectrum, up to photon energies of 280 electron volts. Surprisingly, the high ultraviolet refractive indices of both neutral atoms and ions enabled effective phase matching, even in a multiply ionized plasma. We observed harmonics with very narrow linewidths, while calculations show that the x-rays emerge as nearly time-bandwidth-limited pulse trains of ~100 attoseconds.

  9. The Ultraviolet Surprise. Efficient Soft X-Ray High Harmonic Generation in Multiply-Ionized Plasmas

    SciTech Connect

    Popmintchev, Dimitar; Hernandez-Garcia, Carlos; Dollar, Franklin; Mancuso, Christopher; Perez-Hernandez, Jose A.; Chen, Ming-Chang; Hankla, Amelia; Gao, Xiaohui; Shim, Bonggu; Gaeta, Alexander L.; Tarazkar, Maryam; Romanov, Dmitri A.; Levis, Robert J.; Gaffney, Jim A.; Foord, Mark; Libby, Stephen B.; Jaron-Becker, Agnieskzka; Becker, Andreas; Plaja, Luis; Muranane, Margaret M.; Kapteyn, Henry C.; Popmintchev, Tenio

    2015-12-04

    High-harmonic generation is a universal response of matter to strong femtosecond laser fields, coherently upconverting light to much shorter wavelengths. Optimizing the conversion of laser light into soft x-rays typically demands a trade-off between two competing factors. Reduced quantum diffusion of the radiating electron wave function results in emission from each species which is highest when a short-wavelength ultraviolet driving laser is used. But, phase matching—the constructive addition of x-ray waves from a large number of atoms—favors longer-wavelength mid-infrared lasers. We identified a regime of high-harmonic generation driven by 40-cycle ultraviolet lasers in waveguides that can generate bright beams in the soft x-ray region of the spectrum, up to photon energies of 280 electron volts. Surprisingly, the high ultraviolet refractive indices of both neutral atoms and ions enabled effective phase matching, even in a multiply ionized plasma. We observed harmonics with very narrow linewidths, while calculations show that the x-rays emerge as nearly time-bandwidth–limited pulse trains of ~100 attoseconds.

  10. The Ultraviolet Surprise. Efficient Soft X-Ray High Harmonic Generation in Multiply-Ionized Plasmas

    DOE PAGESBeta

    Popmintchev, Dimitar; Hernandez-Garcia, Carlos; Dollar, Franklin; Mancuso, Christopher; Perez-Hernandez, Jose A.; Chen, Ming-Chang; Hankla, Amelia; Gao, Xiaohui; Shim, Bonggu; Gaeta, Alexander L.; et al

    2015-12-04

    High-harmonic generation is a universal response of matter to strong femtosecond laser fields, coherently upconverting light to much shorter wavelengths. Optimizing the conversion of laser light into soft x-rays typically demands a trade-off between two competing factors. Reduced quantum diffusion of the radiating electron wave function results in emission from each species which is highest when a short-wavelength ultraviolet driving laser is used. But, phase matching—the constructive addition of x-ray waves from a large number of atoms—favors longer-wavelength mid-infrared lasers. We identified a regime of high-harmonic generation driven by 40-cycle ultraviolet lasers in waveguides that can generate bright beams inmore » the soft x-ray region of the spectrum, up to photon energies of 280 electron volts. Surprisingly, the high ultraviolet refractive indices of both neutral atoms and ions enabled effective phase matching, even in a multiply ionized plasma. We observed harmonics with very narrow linewidths, while calculations show that the x-rays emerge as nearly time-bandwidth–limited pulse trains of ~100 attoseconds.« less

  11. Quark masses and mixings in the RS1 model with a condensing 4th generation

    NASA Astrophysics Data System (ADS)

    Hernández, A. E. Cárcamo; Dib, Claudio O.; Neill, Nicolás A.; Zerwekh, Alfonso R.

    2012-02-01

    We study the hierarchy of quark masses and mixings in a model based on a 5-dimensional spacetime with constant curvature of Randall-Sundrum type with two branes, where the Electroweak Symmetry Breaking is caused dynamically by the condensation of a 4th generation of quarks, due to underlying physics from the 5D bulk and the first KK gluons. We first study the hierarchy of quark masses and mixings that can be obtained from purely adjusting the profile localizations, finding that realistic masses are not reproduced unless non trivial hierarchies of underlying 4-fermion interactions from the bulk are included. Then we study global U(1) symmetries that can be imposed in order to obtain non-symmetric modified Fritzsch-like textures in the mass matrices that reproduce reasonably well quark masses and CKM mixings.

  12. Excitation of XPS spectra from nanoscaled particles by local generation of x-rays

    SciTech Connect

    Mallinson, Christopher F.; Castle, James E.

    2015-09-15

    In preliminary work, the authors have shown that use of an aluminum substrate to support a distribution of copper particles enables their characteristic photoelectrons to be observed within the Auger electron spectrum generated by an incident electron beam. This observation raises the possibility of the use of chemical shifts and the corresponding Auger parameter to identify the chemical states present on the surface of individual submicrometer particles within a mixture. In this context, the technique has an advantage in that, unlike conventional Auger electron spectroscopy, the electron beam does not dwell on the particle but on the substrate adjacent to it. Given the importance, for both medical and toxicological reasons, of the surface composition of such particles, the authors have continued to explore the potential of this development. In this contribution, the authors show that proximal excitation of x-rays is equally successful with magnesium substrates. In some regions of the x-ray photoelectron spectrum, the much larger Auger peaks generated by the electron beam can cause inconvenient clustering of Auger and photoelectron peaks. As in conventional x-ray photoelectron spectroscopy, the ability to switch between Al and Mg sources is useful in such situations. In this context, the authors have extended the studies to iron particles where the authors show that use of Al or Mg substrates, as necessary, can make a contribution to clear identification of individual components in the Fe 2p peaks. For this development in electron spectroscopy to achieve its full potential, it is necessary to optimize the beam conditions used to generate the local x-ray to give good selectivity of a given particle. Measurements made in support of this will be given. Of greater concern is a possible problem of local heating associated with x-ray generation. The authors continue to explore this problem and report some progress in minimizing heating of the particle while maintaining

  13. Coherent Soft X-Ray Generation in the Water Window with the EEHG Scheme

    SciTech Connect

    Xiang, D; Stupakov, G.; /SLAC

    2009-05-26

    Recently a scheme entitled echo-enabled harmonic generation (EEHG) was proposed for producing short wavelength FEL radiation that allows far higher harmonic numbers to be accessed as compared with the normal limit arising from incoherent energy spread. In this paper we study the feasibility of a single EEHG stage to generate coherent radiation in the 'water window' (2--4 nm wavelength) directly from a UV seed laser at 190-nm wavelength. We present time-dependent simulation results which demonstrate that the single-stage EEHG FEL can generate high power soft x-ray radiation in the water window with narrow bandwidth close to Fourier transform limit directly from a UV seed laser. The schemes to generate short x-ray pulse from femtosecond to attosecond using EEHG FEL are also discussed.

  14. Compact Pulsed X-Ray Generator Operated At High Repetitive Rates

    NASA Astrophysics Data System (ADS)

    Isobe, Hiroshi; Sato, Eiichi; Kimura, Shingo; Tamakawa, Yoshiharu; Yanagisawa, Toru

    1990-01-01

    A repetitive pulsed x-ray generator achieved with a compact diode utilizing a new type of cathode for biomedical radiography is described. This generator consisted of the following components: a high-voltage power supply, two ceramic condensers of about 850pF, a repetitive impulse switching system, a turbo molecular pump, and an x-ray tube. Since the high-voltage pulser employed a modified Marx circuit, this pulser produced twice the potential of the condenser charging voltage. The x-ray tube was of the demountable-diode type which was connected to the turbo molecular pump and consisted of the following components: a rod-shaped anode tip made of tungsten, a plane cathode made of aluminum and carbon, and a vacuum vessel made of glass with a diameter of 50mm. Two condensers were charged from 30 to 100kV, and the output of this pulser ranged from 50 to 180kV. The x-ray pulse widths primarily increased according to increases in the anode-cathode (A-C space) and their values ranged from 20 to 100ns. The repetitive rate was determined by the condenser capacity, the charging voltage, and the current capacity of the power supply, and its maximum value was about 100Hz. The time integrated x-ray intensities were less than 4.0pC/kg at 0.5m per pulse when the discharge capacity of about 430pF (Marx Circuit) was employed. The effective focal spot size was determined by the diameter of anode tip and its value ranged from 0.5 to 3.0mm in diameter.

  15. High resolution hard x-ray microscope on a second generation synchrotron source

    SciTech Connect

    Tian Yangchao; Li Wenjie; Chen Jie; Liu Longhua; Liu Gang; Tian Jinping; Xiong Ying; Tkachuk, Andrei; Gelb, Jeff; Hsu, George; Yun Wenbing

    2008-10-15

    A full-field, transmission x-ray microscope (TXM) operating in the energy range of 7-11 keV has been installed at the U7A beamline at the National Synchrotron Radiation Laboratory, a second generation synchrotron source operating at 0.8 GeV. Although the photon flux at sample position in the operating energy range is significantly low due to its relatively large emittance, the TXM can get high quality x-ray images with a spatial resolution down to 50 nm with acceptable exposure time. This TXM operates in either absorption or Zernike phase contrast mode with similar resolution. This TXM is a powerful analytical tool for a wide range of scientific areas, especially studies on nanoscale phenomena and structural imaging in biology, materials science, and environmental science. We present here the property of the x-ray source, beamline design, and the operation and key optical components of the x-ray TXM. Plans to improve the throughput of the TXM will be discussed.

  16. High resolution hard x-ray microscope on a second generation synchrotron source.

    PubMed

    Tian, Yangchao; Li, Wenjie; Chen, Jie; Liu, Longhua; Liu, Gang; Tkachuk, Andrei; Tian, Jinping; Xiong, Ying; Gelb, Jeff; Hsu, George; Yun, Wenbing

    2008-10-01

    A full-field, transmission x-ray microscope (TXM) operating in the energy range of 7-11 keV has been installed at the U7A beamline at the National Synchrotron Radiation Laboratory, a second generation synchrotron source operating at 0.8 GeV. Although the photon flux at sample position in the operating energy range is significantly low due to its relatively large emittance, the TXM can get high quality x-ray images with a spatial resolution down to 50 nm with acceptable exposure time. This TXM operates in either absorption or Zernike phase contrast mode with similar resolution. This TXM is a powerful analytical tool for a wide range of scientific areas, especially studies on nanoscale phenomena and structural imaging in biology, materials science, and environmental science. We present here the property of the x-ray source, beamline design, and the operation and key optical components of the x-ray TXM. Plans to improve the throughput of the TXM will be discussed. PMID:19044720

  17. High resolution hard x-ray microscope on a second generation synchrotron source

    NASA Astrophysics Data System (ADS)

    Tian, Yangchao; Li, Wenjie; Chen, Jie; Liu, Longhua; Liu, Gang; Tkachuk, Andrei; Tian, Jinping; Xiong, Ying; Gelb, Jeff; Hsu, George; Yun, Wenbing

    2008-10-01

    A full-field, transmission x-ray microscope (TXM) operating in the energy range of 7-11 keV has been installed at the U7A beamline at the National Synchrotron Radiation Laboratory, a second generation synchrotron source operating at 0.8 GeV. Although the photon flux at sample position in the operating energy range is significantly low due to its relatively large emittance, the TXM can get high quality x-ray images with a spatial resolution down to 50 nm with acceptable exposure time. This TXM operates in either absorption or Zernike phase contrast mode with similar resolution. This TXM is a powerful analytical tool for a wide range of scientific areas, especially studies on nanoscale phenomena and structural imaging in biology, materials science, and environmental science. We present here the property of the x-ray source, beamline design, and the operation and key optical components of the x-ray TXM. Plans to improve the throughput of the TXM will be discussed.

  18. High-order harmonic generation enhanced by x rays from free-electron lasers

    NASA Astrophysics Data System (ADS)

    Buth, Christian; Kohler, Markus C.; He, Feng; Hatsagortsyan, Karen Z.; Ullrich, Joachim; Keitel, Christoph H.

    2012-06-01

    We theoretically examine high-order harmonic generation (HHG), by an intense near-infrared (nir) laser, in the light of the emerging, intense x-ray free electron lasers (FELs) which have started to revolutionize x-ray science. We present two theories based on modified three-step models of HHG. Once, we combine HHG with resonant x-ray excitation of a core electron into the transient valence vacancy that is created in the course of the HHG process via tunnel ionization (first step of HHG) by the nir light. When the continuum electron is driven back to the parent ion, a recombination with the valence and the core hole may occur. Modified HHG spectra are determined and analyzed for krypton on the 3d ->4p resonance and for neon on the 1s ->2p resonance. Another time, we examine HHG where tunnel ionization by the nir light is replaced by direct x-ray ionization of a core electron. We use the boosted HHG radiation from 1s electrons of neon to predict single attosecond pulses in the kiloelectronvolt regime. For both presented schemes, we find substantial HHG yield from the recombination of the continuum electron with the core hole. Our research brings the capabilities of HHG-based sources to FELs.

  19. Characterization of neutron yield and x-ray spectra of a High Flux Neutron Generator (HFNG)

    NASA Astrophysics Data System (ADS)

    Nnamani, Nnaemeka; HFNG Collaboration

    2015-04-01

    The High Flux Neutron Generator (HFNG) is a DD plasma-based source, with a self-loading target intended for fundamental science and engineering applications, including 40 Ar/39 Ar geochronology, neutron cross section measurements, and radiation hardness testing of electronics. Our first estimate of the neutron yield, based on the population of the 4.486 hour 115 In isomer gave a neutron yield of the order 108 n/sec; optimization is ongoing to achieve the design target of 1011 n/sec. Preliminary x-ray spectra showed prominent energy peaks which are likely due to atomic line-emission from back-streaming electrons accelerated up to 100 keV impinging on various components of the HFNG chamber. Our x-ray and neutron diagnostics will aid us as we continue to evolve the design to suppress back-streaming electrons, necessary to achieve higher plasma beam currents, and thus higher neutron flux. This talk will focus on the characterization of the neutron yield and x-ray spectra during our tests. A collimation system is being installed near one of the chamber ports for improved observation of the x-ray spectra. This work is supported by NSF Grant No. EAR-0960138, U.S. DOE LBNL Contract No. DE-AC02-05CH11231, U.S. DOE LLNL Contract No. DE-AC52-07NA27344, and the UC Office of the President Award 12-LR-238745.

  20. High-intensity soft-flash x-ray generator utilizing a low-vacuum diode

    NASA Astrophysics Data System (ADS)

    Isobe, Hiroshi; Sato, Eiichi; Shikoda, Arimitsu; Takahashi, Kei; Tamakawa, Yoshiharu; Yanagisawa, Toru

    1991-04-01

    The fundamental studies on the high-intensity single flash x-ray generator having a low-vacuum diode for biomedical radiography are described. This generator consisted of the following essential components: a high-voltage power supply, a high-voltage pulser with a coaxial oil condenser of l5OnF, a low impedance transmission line made from four coaxial cables with lengths of 5. 6m and a total capacity of 292OpF, a mechanical booster pump, and a flash x-ray tube. The x-ray tube was of the diode-type which was connected to the booster pump with a constant pressure of 1. 7Pa and consisted of the following major devices: a long anode tip made of tungsten with a diameter (D) of less than 3. 0mm and a length (L) of 50mm, a long cathode tip made of tungsten with a D of 1. 0mm and a L of 40mm, a polyoxymethylene insulator, lead diaphragms, and an x-ray window made of polyethylene terephthalate. The coaxial oil condenser in the pulser was charged from 50 to 90kV, and the electric charges in the condenser were discharged to the flash x-ray tube through a transmission line by using a gas gap switch with a highcurrent capacity. The peak voltage increased according to increases in the condenser charged voltage and its value was more than the charged voltage. The peak current primarily increased when the charged voltage was increased, and its value was less than 4OkA. The pulse width of the flash x-rays ranged from 60 to 8Ons, and the time integrated x-ray intensity with a charged voltage of 90kV and an anode cathode (A-C) space of 3. 0mm was about 4pC/kg at 1. Om per pulse the source. The effective focal spot size was primarily determined by the diameter of the anode tip, and its value was about 3. 0mm when an anode diameter of 3. 0mm was employed.

  1. The Generation-X X-ray Observatory Vision Mission and Technology Study

    NASA Technical Reports Server (NTRS)

    Figueroa-Feliciano, Enectali

    2004-01-01

    The new frontier in astrophysics is the study of the birth and evolution of the first stars, galaxies and black holes in the early Universe. X-ray astronomy opens a window into these objects by studying the emission from black holes, supernova explosions and the gamma-ray burst afterglows of massive stars. However, such objects are beyond the grasp of current or near-future observatories. X-ray imaging and spectroscopy of such distant objects will require an X-ray telescope with large collecting area and high angular resolution. Our team has conceived the Generation-X Vision Mission based on an X-ray observatory with 100 sq m collecting area at 1 keV (1000 times larger than Chandra) and 0.1 arcsecond angular resolution (several times better than Chandra and 50 times better than the Constellation-X resolution goal). Such an observatory would be capable of detecting the earliest black holes and galaxies in the Universe, and will also study extremes of density, gravity, magnetic fields, and kinetic energy which cannot be created in laboratories. NASA has selected the Generation-X mission for study under its Vision Mission Program. We describe the studies being performed to develop the mission concept and define candidate technologies and performance requirements for Generation-X. The baseline Generation-X mission involves four 8m diameter X-ray telescopes operating at Sun-Earth L2. We trade against an alternate concept of a single 26m diameter telescope with focal plane instruments on a separate spacecraft. A telescope of this size will require either robotic or human-assisted in-flight assembly. The required effective area implies that extremely lightweight grazing incidence X-ray optics must be developed. To achieve the required aerial density of at least 100 times lower than in Chandra, we will study 0.1mm thick mirrors which have active on-orbit figure control. We discuss the suite of required detectors, including a large FOV high angular resolution imager, a

  2. X-Ray Lasers

    ERIC Educational Resources Information Center

    Chapline, George; Wood, Lowell

    1975-01-01

    Outlines the prospects of generating coherent x rays using high-power lasers and indentifies problem areas in their development. Indicates possible applications for coherent x rays in the fields of chemistry, biology, and crystallography. (GS)

  3. Compton Backscattered X-rays from Self-Generated Laser Wiggler in a Laser Wakefield Accelerator

    NASA Astrophysics Data System (ADS)

    Ting, Antonio; Kaganovich, Dmitri; Hafizi, Bahman; Palastro, John; Helle, Michael; Gordon, Daniel; Chen, Yu-Hsin; Seely, John

    2014-10-01

    A unique Compton backscattering configuration for generating monochromatic, short pulse, and potentially coherent x-rays in a Laser Wakefield Accelerator (LWFA) is being studied at the Naval Research Laboratory. Reflection mechanisms such as stimulated Raman scattering and shock-created density gradients in a plasma can generate the required backward-travelling laser pulse directly from the same laser pulse used in the LWFA, i.e., the high energy electron beam and the counter-propagating photon beam are both self-generated by an ultrashort laser pulse in plasma. The automatic alignment of the counter-propagating electrons and photons together with the extended interaction distance and tightly guided beam sizes in a LWFA can lead to a high-gain situation for the Doppler upshifted forward propagating x-rays. Possibilities for exponential gain to achieve coherent generation of the x-rays are under investigation. Theoretical, numerical, and preliminary experimental results will be presented. This work is supported by DOE and NRL 6.1 funding.

  4. X-ray diffraction imaging--a multi-generational perspective.

    PubMed

    Harding, G

    2009-02-01

    A brief description is given of some applications of X-ray diffraction imaging (XDI) in security screening, including detection of narcotics and a wide range of explosives: organic (plastic) explosives, liquids, home-made explosives (HMEs) and special nuclear materials (SNMs). A Bayesian formulation of the "rare event scenario" is presented, allowing the probability to be quantified that an unlikely threat is indeed present when an uncertain detection system raises an alarm. Granted the utility of X-ray diffraction (XRD) as a significant screening modality for false-alarm resolution, the topic of its technological feasibility is addressed. It is shown that, in analogy to computed tomography, XDI permits a significant reduction to be achieved in measurement time per object volume element (voxel) compared with that of a classical X-ray diffractometer. This reduction can be accomplished by designing the XDI system to record energy-dispersive XRD profiles from many volume elements (object voxels) in parallel. A general scheme for designing "massively-parallel" (MP) XDI systems is presented. XDI configurations of the first generation (1 voxels(-1)), second generation (100 voxelss(-1)) and third generation (10(4) voxelss(-1)) are presented and discussed. Three alternative 3rd Generation XDI geometries, namely: direct fan-beam; parallel (waterfall) beam; and inverse fan-beam are compared with respect to technological realization. Directions for future development of XDI in screening applications are outlined. PMID:18805014

  5. Generation of intense attosecond x-ray pulses using ultraviolet laser induced microbunching in electron beams

    NASA Astrophysics Data System (ADS)

    Xiang, D.; Huang, Z.; Stupakov, G.

    2009-06-01

    We propose a scheme that combines the echo-enabled harmonic generation technique with the bunch compression and allows one to generate harmonic numbers of a few hundred in a microbunched beam through up-conversion of the frequency of an ultraviolet seed laser. A few-cycle intense laser is used to generate the required energy chirp in the beam for bunch compression and for selection of an attosecond x-ray pulse. Sending this beam through a short undulator results in an intense isolated attosecond x-ray pulse. Using a representative realistic set of parameters, we show that 1 nm x-ray pulse with peak power of a few hundred MW and duration as short as 20 attoseconds (FWHM) can be generated from a 200 nm ultraviolet seed laser. The proposed scheme may enable the study of electronic dynamics with a resolution beyond the atomic unit of time (˜24 attoseconds) and may open a new regime of ultrafast sciences.

  6. Generating intense fully coherent soft x-ray radiation based on a laser-plasma accelerator.

    PubMed

    Feng, Chao; Xiang, Dao; Deng, Haixiao; Huang, Dazhang; Wang, Dong; Zhao, Zhentang

    2015-06-01

    Laser-plasma based accelerator has the potential to dramatically reduce the size and cost of future x-ray light sources to the university-laboratory scale. However, the large energy spread of the laser-plasma accelerated electron beam may hinder the way for short wavelength free-electron laser generation. In this paper, we propose a novel method for directly imprinting strong coherent micro-bunching on the electron beam with large intrinsic energy spread by using a wavefront-tilted conventional optical laser beam and a weak dipole magnet. Theoretical analysis and numerical simulations demonstrate that this technique can be used for the generation of fully coherent femtosecond soft x-ray radiation at gigawatts level with a very short undulator. PMID:26072855

  7. A Compact X-ray Generator Using a Nanostructured Field Emission Cathode and a Microstructured Transmission Anode

    NASA Astrophysics Data System (ADS)

    Cheng, S.; Hill, F. A.; Heubel, E. V.; Velás quez-García, L. F.

    2013-12-01

    We report the design, fabrication, and preliminary characterization of a compact X-ray generator for improved X-ray absorption imaging that uses a nanostructured field emission cathode (FEC) as the electron source and a microstructured transmission anode as the X-ray generating element. FECs consume less power, respond faster, and tolerate lower vacuum than thermionic cathodes used in conventional X-ray generators. The use of a transmission anode, instead of a conventional reflection anode, allows filtering of the background radiation (brems strahlung) while allowing efficient generation of X-rays at lower voltages by exciting atomic shell transitions, resulting in emission of X-rays with narrow spectral linewidth for sharper imaging of biological tissue. The fabricated FEC contains arrays of self-aligned, gated field emitters that turn on at bias voltages under 30 V and transmit 99.5% of the electrons to the anode. The FEC emits a maximum current of 1.2 μA per field emitter (588 μA total array current) at a bias voltage of 85 V. A facility is built and tested to generate X-rays with an FEC and a transmission anode. Using the facility, we obtained an X-ray absorption image of an ex-vivos ample that clearly shows softtissue and fine bone structures.

  8. Compact monochromatic flash x-ray generator utilizing a disk-cathode molybdenum tube

    SciTech Connect

    Sato, Eiichi; Tanaka, Etsuro; Mori, Hidezo; Kawai, Toshiaki; Ichimaru, Toshio; Sato, Shigehiro; Takayama, Kazuyoshi; Ido, Hideaki

    2005-01-01

    The high-voltage condensers in a polarity-inversion two-stage Marx surge generator are charged from -50 to -70 kV by a power supply, and the electric charges in the condensers are discharged to an x-ray tube after closing gap switches in the surge generator with a trigger device. The x-ray tube is a demountable diode, and the turbo molecular pump evacuates air from the tube with a pressure of approximately 1 mPa. Clean molybdenum K{alpha} lines are produced using a 20 {mu}m-thick zirconium filter, since the tube utilizes a disk cathode and a rod target, and bremsstrahlung rays are not emitted in the opposite direction to that of electron acceleration. At a charging voltage of -70 kV, the instantaneous tube voltage and current were 120 kV and 1.0 kA, respectively. The x-ray pulse widths were approximately 70 ns, and the generator produced instantaneous number of K{alpha} photons was approximately 3x10{sup 7} photons/cm{sup 2} per pulse at 0.5 m from the source of 3.0 mm in diameter.

  9. Compact monochromatic flash x-ray generator utilizing a disk-cathode molybdenum tube.

    PubMed

    Sato, Eiichi; Tanaka, Etsuro; Mori, Hidezo; Kawai, Toshiaki; Ichimaru, Toshio; Sato, Shigehiro; Takayama, Kazuyoshi; Ido, Hideaki

    2005-01-01

    The high-voltage condensers in a polarity-inversion two-stage Marx surge generator are charged from -50 to -70 kV by a power supply, and the electric charges in the condensers are discharged to an x-ray tube after closing gap switches in the surge generator with a trigger device. The x-ray tube is a demountable diode, and the turbo molecular pump evacuates air from the tube with a pressure of approximately 1 mPa. Clean molybdenum Kalpha lines are produced using a 20 microm-thick zirconium filter, since the tube utilizes a disk cathode and a rod target, and bremsstrahlung rays are not emitted in the opposite direction to that of electron acceleration. At a charging voltage of -70 kV, the instantaneous tube voltage and current were 120 kV and 1.0 kA, respectively. The x-ray pulse widths were approximately 70 ns, and the generator produced instantaneous number of Kalpha photons was approximately 3 x 10(7) photons/cm2 per pulse at 0.5 m from the source of 3.0 mm in diameter. PMID:15719954

  10. Few-cycle pulse generation in an x-ray free-electron laser.

    PubMed

    Dunning, D J; McNeil, B W J; Thompson, N R

    2013-03-01

    A method is proposed to generate trains of few-cycle x-ray pulses from a free-electron laser (FEL) amplifier via a compact "afterburner" extension consisting of several few-period undulator sections separated by electron chicane delays. Simulations show that in the hard x ray (wavelength ~0.1 nm; photon energy ~10 keV) and with peak powers approaching normal FEL saturation (GW) levels, root mean square pulse durations of 700 zs may be obtained. This is approximately two orders of magnitude shorter than that possible for normal FEL amplifier operation. The spectrum is discretely multichromatic with a bandwidth envelope increased by approximately 2 orders of magnitude over unseeded FEL amplifier operation. Such a source would significantly enhance research opportunity in atomic dynamics and push capability toward nuclear dynamics. PMID:23521266

  11. Generation of subterawatt-attosecond pulses in a soft x-ray free-electron laser

    NASA Astrophysics Data System (ADS)

    Huang, Senlin; Ding, Yuantao; Huang, Zhirong; Marcus, Gabriel

    2016-08-01

    We propose a novel scheme to generate attosecond soft x rays in a self-seeded free-electron laser (FEL) suitable for enabling attosecond spectroscopic investigations. A time-energy chirped electron bunch with additional sinusoidal energy modulation is adopted to produce a short seed pulse through a self-seeding monochromator. This short seed pulse, together with high electron current spikes and a cascaded delay setup, enables a high-efficiency FEL with a fresh bunch scheme. Simulations show that using the Linac Coherent Light Source (LCLS) parameters, soft x-ray pulses with a FWHM of 260 attoseconds and a peak power of 0.5 TW can be obtained. This scheme also has the feature of providing a stable central wavelength determined by the self-seeding monochromator.

  12. Few-Cycle Pulse Generation in an X-Ray Free-Electron Laser

    NASA Astrophysics Data System (ADS)

    Dunning, D. J.; McNeil, B. W. J.; Thompson, N. R.

    2013-03-01

    A method is proposed to generate trains of few-cycle x-ray pulses from a free-electron laser (FEL) amplifier via a compact “afterburner” extension consisting of several few-period undulator sections separated by electron chicane delays. Simulations show that in the hard x ray (wavelength ˜0.1nm; photon energy ˜10keV) and with peak powers approaching normal FEL saturation (GW) levels, root mean square pulse durations of 700 zs may be obtained. This is approximately two orders of magnitude shorter than that possible for normal FEL amplifier operation. The spectrum is discretely multichromatic with a bandwidth envelope increased by approximately 2 orders of magnitude over unseeded FEL amplifier operation. Such a source would significantly enhance research opportunity in atomic dynamics and push capability toward nuclear dynamics.

  13. Attosecond x-ray source generation from two-color polarized gating plasmonic field enhancement

    SciTech Connect

    Feng, Liqiang; State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023 ; Yuan, Minghu; Chu, Tianshu; Institute for Computational Sciences and Engineering, Laboratory of New Fiber Materials and Modern Textile, The Growing Base for State Key Laboratory, Qingdao University, Qingdao 266071

    2013-12-15

    The plasmonic field enhancement from the vicinity of metallic nanostructures as well as the polarization gating technique has been utilized to the generation of the high order harmonic and the single attosecond x-ray source. Through numerical solution of the time-dependent Schrödinger equation, for moderate the inhomogeneity and the polarized angle of the two fields, we find that not only the harmonic plateau has been extended and enhanced but also the single short quantum path has been selected to contribute to the harmonic. As a result, a series of 50 as pulses around the extreme ultraviolet and the x-ray regions have been obtained. Furthermore, by investigating the other parameters effects on the harmonic emission, we find that this two-color polarized gating plasmonic field enhancement scheme can also be achieved by the multi-cycle pulses, which is much better for experimental realization.

  14. Flexible Field Emitter for X-ray Generation by Implanting CNTs into Nickel Foil.

    PubMed

    Sun, Bin; Wang, Yan; Ding, Guifu

    2016-12-01

    This paper reports on a flexible Ni micro wire with CNTs embedded into its surface. By using micromachining technology, for the first time, we could implant nanoscale materials into micro-scale metal substrate at room temperature. Thanks to the effective direct contact and the strong interactions between CNTs and the substrate, field emission current of 1.11 mA (current density of 22.2 mA/cm(2)) could be achieved from the micro wire. Moreover, the wire shows excellent mechanical properties for large amplitude bending, which is beneficial for geometric designing. To check the practical application of the wire, a simplified X-ray imaging system was set up by modifying a conventional tube. The gray shade that appears on the sensitive film after being exposed to the radiation confirms the X-ray generation. PMID:27613070

  15. Theoretical analysis of hard x-ray generation by nonperturbative interaction of ultrashort light pulses with a metal

    PubMed Central

    Weisshaupt, Jannick; Juvé, Vincent; Holtz, Marcel; Woerner, Michael; Elsaesser, Thomas

    2015-01-01

    The interaction of intense femtosecond pulses with metals allows for generating ultrashort hard x-rays. In contrast to plasma theories, tunneling from the target into vacuum is introduced as electron generation step, followed by vacuum acceleration in the laser field and re-entrance into the target to generate characteristic x-rays and Bremsstrahlung. For negligible space charge in vacuum, the Kα flux is proportional to the incident intensity and the wavelength squared, suggesting a strong enhancement of the x-ray flux by mid-infrared driving pulses. This prediction is in quantitative agreement with experiments on femtosecond Cu Kα generation. PMID:26798790

  16. The generation of rapid solar flare hard X-ray and microwave fluctuations in current sheets

    NASA Technical Reports Server (NTRS)

    Holman, Gordon D.

    1986-01-01

    The generation of rapid fluctuations, or spikes, in hard X-ray and microwave bursts via the disruption of electron heating and acceleration in current sheets is studied. It is found that 20 msec hard X-ray fluctuations can be thermally generated in a current sheet if the resistivity in the sheet is highly anomalous, the plasma density in the emitting region is relatively high, and the volume of the emitting region is greater than that of the current sheet. A specific mechanism for producing the fluctuations, involving heating in the presence of ion acoustic turbulence and a constant driving electric field, and interruption of the heating by a strong two-stream instability, is discussed. Variations upon this mechanism are also discussed. This mechanism also modulates electron acceleration, as required for the microwave spike emission. If the hard X-ray emission at energies less than approx. 1000 keV is nonthermal bremsstrahlung, the coherent modulation of electron acceleration in a large number of current sheets is required.

  17. Highly bright X-ray generator using heat of fusion with a specially designed rotating anticathode

    PubMed Central

    Sakabe, N.; Ohsawa, S.; Sugimura, T.; Ikeda, M.; Tawada, M.; Watanabe, N.; Sasaki, K.; Ohshima, K.; Wakatsuki, M.; Sakabe, K.

    2008-01-01

    A new type of rotating anticathode X-ray generator has been developed, in which the electron beam irradiates the inner surface of a U-shaped anticathode (Cu). A high-flux electron beam is focused on the inner surface by optimizing the shape of the bending magnet. The power of the electron beam can be increased to the point at which the irradiated part of the inner surface is melted, because a strong centrifugal force fixes the melted part on the inner surface. When the irradiated part is melted, a large amount of energy is stored as the heat of fusion, resulting in emission of X-rays 4.3 times more brilliant than can be attained by a conventional rotating anticathode. Oscillating translation of the irradiated position on the inner surface during use is expected to be very advantageous for extending the target life. A carbon film coating on the inner surface is considered to suppress evaporation of the target metal and will be an important technique in further realization of highly bright X-ray generation. PMID:18421146

  18. Highly bright X-ray generator using heat of fusion with a specially designed rotating anticathode.

    PubMed

    Sakabe, N; Ohsawa, S; Sugimura, T; Ikeda, M; Tawada, M; Watanabe, N; Sasaki, K; Ohshima, K; Wakatsuki, M; Sakabe, K

    2008-05-01

    A new type of rotating anticathode X-ray generator has been developed, in which the electron beam irradiates the inner surface of a U-shaped anticathode (Cu). A high-flux electron beam is focused on the inner surface by optimizing the shape of the bending magnet. The power of the electron beam can be increased to the point at which the irradiated part of the inner surface is melted, because a strong centrifugal force fixes the melted part on the inner surface. When the irradiated part is melted, a large amount of energy is stored as the heat of fusion, resulting in emission of X-rays 4.3 times more brilliant than can be attained by a conventional rotating anticathode. Oscillating translation of the irradiated position on the inner surface during use is expected to be very advantageous for extending the target life. A carbon film coating on the inner surface is considered to suppress evaporation of the target metal and will be an important technique in further realization of highly bright X-ray generation. PMID:18421146

  19. Conditions for the generation of cytotoxic CD4(+) Th cells that enhance CD8(+) CTL-mediated tumor regression.

    PubMed

    Li, Kunyu; Baird, Margaret; Yang, Jianping; Jackson, Chris; Ronchese, Franca; Young, Sarah

    2016-08-01

    Adoptive cell therapies (ACTs) using tumor-reactive T cells have shown clinical benefit and potential for cancer treatment. While the majority of the current ACT are focused on using CD8(+) cytotoxic T lymphocytes (CTL), others have shown that the presence of tumor-reactive CD4(+) T helper (Th) cells can greatly enhance the anti-tumor activity of CD8(+) CTL. However, difficulties in obtaining adequate numbers of CD4(+) Th cells through in vitro expansion can limit the application of CD4 Th cells in ACT. This study aims to optimize the culture conditions for mouse CD4 T cells to provide basic information for animal studies of ACT using CD4 T cells. Taking advantage of the antigen-specificity of CD4(+) Th cells from OT-II transgenic mice, we examined different methodologies for generating antigen-specific CD4(+) Th1 cells in vitro. We found that cells grown in complete advanced-DMEM/F12 medium supplemented with low-dose IL-2 and IL-7 induced substantial cell expansion. These Th cells were Th1-like, as they expressed multiple Th1-cytokines and exhibited antigen-specific cytotoxicity. In addition co-transfer of these CD4(+) Th1-like cells with CD8(+) CTL significantly enhanced tumor regression, leading to complete cure in 80% of mice bearing established B16-OVA. These observations indicate that the CD4(+) Th1-like cells generated using the method we optimized are functionally active to eliminate their target cells, and can also assist CD8(+) CTL to enhance tumor regression. The findings of this study provide valuable data for further research into in vitro expansion of CD4(+) Th1-like cells, with potential applications to cancer treatment involving ACT. PMID:27588200

  20. Conditions for the generation of cytotoxic CD4+ Th cells that enhance CD8+ CTL-mediated tumor regression

    PubMed Central

    Li, Kunyu; Baird, Margaret; Yang, Jianping; Jackson, Chris; Ronchese, Franca; Young, Sarah

    2016-01-01

    Adoptive cell therapies (ACTs) using tumor-reactive T cells have shown clinical benefit and potential for cancer treatment. While the majority of the current ACT are focused on using CD8+ cytotoxic T lymphocytes (CTL), others have shown that the presence of tumor-reactive CD4+ T helper (Th) cells can greatly enhance the anti-tumor activity of CD8+ CTL. However, difficulties in obtaining adequate numbers of CD4+ Th cells through in vitro expansion can limit the application of CD4 Th cells in ACT. This study aims to optimize the culture conditions for mouse CD4 T cells to provide basic information for animal studies of ACT using CD4 T cells. Taking advantage of the antigen-specificity of CD4+ Th cells from OT-II transgenic mice, we examined different methodologies for generating antigen-specific CD4+ Th1 cells in vitro. We found that cells grown in complete advanced-DMEM/F12 medium supplemented with low-dose IL-2 and IL-7 induced substantial cell expansion. These Th cells were Th1-like, as they expressed multiple Th1-cytokines and exhibited antigen-specific cytotoxicity. In addition co-transfer of these CD4+ Th1-like cells with CD8+ CTL significantly enhanced tumor regression, leading to complete cure in 80% of mice bearing established B16-OVA. These observations indicate that the CD4+ Th1-like cells generated using the method we optimized are functionally active to eliminate their target cells, and can also assist CD8+ CTL to enhance tumor regression. The findings of this study provide valuable data for further research into in vitro expansion of CD4+ Th1-like cells, with potential applications to cancer treatment involving ACT. PMID:27588200

  1. Characteristics of a capillary-discharge flash x-ray generator

    NASA Astrophysics Data System (ADS)

    Sato, Eiichi; Hayasi, Yasuomi; Usuki, Tatsumi; Sato, Koetsu; Takayama, Kazuyoshi; Ido, Hideaki

    2002-11-01

    The fundamental experiments for measuring soft x-ray characteristics from the vacuum capillary are described. These experiments are primarily performed in order to generate line spectra such as x-ray lasers. The generator consists of a high-voltage power supply, a polarity-inversion ignitron pulse generator, a turbo-molecular pump, and a radiation tube with a capillary. A high-voltage condenser of 0.2 μF in the pulse generator is charged up to 20 kV by the power supply, and the electric charges in the condenser are discharged to the capillary in the tube after closing the ignitron. During the discharge, weakly ionized plasma forms on the inner and outer sides of a capillary. In the present work, the pump evacuates air from the tube with a pressure of about 1 mPa, and a demountable capillary was developed in order to measure x-ray spectra according to changes in the capillary length. In this capillary, the anode (target) and cathode elements can be changed corresponding to the objectives. The capillary diameter is 2.0 mm, and the length is adjusted from 1 to 50 mm. When a capillary with aluminum anode and cathode electrodes was employed, both the cathode voltage and the discharge current almost displayed damp oscillations. The peak values of the voltage and current increased when the charging voltage was increased and their maximum values were -10.8 kV and 4.7 kV, respectively. The x-ray durations observed by a 1.6 μm aluminum filter were less than 30 μs, and we detected the aluminum characteristic x-ray intensity using a 6.8 μm aluminum filter. In the spectrum measurement, two sets of aluminum and titanium electrodes were employed, and we observed multi-line spectra. The line photon energies seldom varied according to changes in teh condenser charging voltage and to changes in the electrode element. In the case where the titanium electrode was employed, the line number decreased with corresponding decreases in the capillary length. Compared with incoherent

  2. Enhanced k-edge angiography utilizing a superfluorescent x-ray generator with a gadolinium-target tube

    NASA Astrophysics Data System (ADS)

    Sato, Eiichi; Germer, Rudolf; Obara, Haruo; Tanaka, Etsuro; Mori, Hidezo; Kawai, Toshiaki; Inoue, Takashi; Ogawa, Akira; Sato, Shigehiro; Takayama, Kazuyoshi

    2007-01-01

    The gadolinium plasma flash x-ray generator is useful for performing high-speed enhanced K-edge angiography using cone beams because K-series characteristic x-rays from the gadolinium target are absorbed effectively by iodine-based contrast media. In the flash x-ray generator, a 150 nF condenser is charged up to 80 kV by a power supply, and flash x-rays are produced by the discharging. The x-ray tube is a demountable cold-cathode diode, and the turbomolecular pump evacuates air from the tube with a pressure of approximately 1 mPa. Since the electric circuit of the high-voltage pulse generator employs a cable transmission line, the high-voltage pulse generator produces twice the potential of the condenser charging voltage. At a charging voltage of 80 kV, the estimated maximum tube voltage and current are approximately 160 kV and 40 kA, respectively. When the charging voltage was increased, the K-series characteristic x-ray intensities of gadolinium increased. Bremsstrahlung x-ray intensity rate decreased with increasing the charging voltage, and clean K lines were produced with a charging voltage of 80 kV. The x-ray pulse widths were approximately 100 ns, and the time-integrated x-ray intensity had a value of approximately 500 μGy at 1.0 m from the x-ray source with a charging voltage of 80 kV. Angiography was performed using a filmless computed radiography (CR) system and iodine-based contrast media. In the angiography of nonliving animals, we observed fine blood vessels of approximately 100 μm with high contrasts.

  3. Quantitative X-ray mapping, scatter diagrams and the generation of correction maps to obtain more information about your material

    NASA Astrophysics Data System (ADS)

    Wuhrer, R.; Moran, K.

    2014-03-01

    Quantitative X-ray mapping with silicon drift detectors and multi-EDS detector systems have become an invaluable analysis technique and one of the most useful methods of X-ray microanalysis today. The time to perform an X-ray map has reduced considerably with the ability to map minor and trace elements very accurately due to the larger detector area and higher count rate detectors. Live X-ray imaging can now be performed with a significant amount of data collected in a matter of minutes. A great deal of information can be obtained from X-ray maps. This includes; elemental relationship or scatter diagram creation, elemental ratio mapping, chemical phase mapping (CPM) and quantitative X-ray maps. In obtaining quantitative x-ray maps, we are able to easily generate atomic number (Z), absorption (A), fluorescence (F), theoretical back scatter coefficient (η), and quantitative total maps from each pixel in the image. This allows us to generate an image corresponding to each factor (for each element present). These images allow the user to predict and verify where they are likely to have problems in our images, and are especially helpful to look at possible interface artefacts. The post-processing techniques to improve the quantitation of X-ray map data and the development of post processing techniques for improved characterisation are covered in this paper.

  4. Visualization of x-ray computer tomography using computer-generated holography

    NASA Astrophysics Data System (ADS)

    Daibo, Masahiro; Tayama, Norio

    1998-09-01

    The theory converted from x-ray projection data to the hologram directly by combining the computer tomography (CT) with the computer generated hologram (CGH), is proposed. The purpose of this study is to offer the theory for realizing the all- electronic and high-speed seeing through 3D visualization system, which is for the application to medical diagnosis and non- destructive testing. First, the CT is expressed using the pseudo- inverse matrix which is obtained by the singular value decomposition. CGH is expressed in the matrix style. Next, `projection to hologram conversion' (PTHC) matrix is calculated by the multiplication of phase matrix of CGH with pseudo-inverse matrix of the CT. Finally, the projection vector is converted to the hologram vector directly, by multiplication of the PTHC matrix with the projection vector. Incorporating holographic analog computation into CT reconstruction, it becomes possible that the calculation amount is drastically reduced. We demonstrate the CT cross section which is reconstituted by He-Ne laser in the 3D space from the real x-ray projection data acquired by x-ray television equipment, using our direct conversion technique.

  5. X-ray optics developments at the APS for third-generation synchrotron radiation sources

    SciTech Connect

    Mills, D.M.

    1996-09-01

    High brilliance third-generation synchrotron radiation sources simultaneously provide both a need and an opportunity for the development of new x-ray optical components. The high power and power densities of the x-ray beams produced by insertion devices have forced researchers to consider novel, and what may seem like exotic, approaches to the mitigation of thermal distortions that can dilute the beam brilliance delivered to the experiment or next optical component. Once the power has been filtered by such high heat load optical elements, specialized components can be employed that take advantage of the high degree of brilliance. This presentation reviews the performance of optical components that have been designed, fabricated, and tested at the Advanced Photon Source, starting with high heat load components and followed by examples of several specialized devices such as a milli-eV resolution (in-line) monochromator, a high energy x-ray phase retarder, and a phase zone plate with submicron focusing capability.

  6. Phase-matched generation of coherent soft and hard X-rays using IR lasers

    DOEpatents

    Popmintchev, Tenio V.; Chen, Ming-Chang; Bahabad, Alon; Murnane, Margaret M.; Kapteyn, Henry C.

    2013-06-11

    Phase-matched high-order harmonic generation of soft and hard X-rays is accomplished using infrared driving lasers in a high-pressure non-linear medium. The pressure of the non-linear medium is increased to multi-atmospheres and a mid-IR (or higher) laser device provides the driving pulse. Based on this scaling, also a general method for global optimization of the flux of phase-matched high-order harmonic generation at a desired wavelength is designed.

  7. Generation of ultrashort pulses of electrons, X-rays and optical pulses by relativistically strong light

    SciTech Connect

    Umstadter, D.; Banerjee, S.; Chen, S.; Sepke, S.; Maksimchuk, A.; Valenzuela, A.; Rousse, A.; Shah, R.; Phuoc, K. Ta

    2006-04-07

    We report recent results of experiments in which relativistic optical effects play an important role, at peak laser intensities above 1019 W/cm2. These effects are leading to novel radiation sources, all with femtosecond pulse durations: (1) the generation of optical photons by means of pulse compression via relativistic cross-phase modulation, (2) ponderomotive deflection of laser accelerated electron beams, and (3) the generation of well-collimated keV-energy x-ray beams by means of either Thomson scattering or betatron oscillations in ion channels.

  8. Generation of phase - matched coherent point source in plasma media by propagated X-ray laser seeded beam

    NASA Astrophysics Data System (ADS)

    Pikuz, T.; Faenov, A.; Magnitskiy, S.; Nagorskiy, N.; Tanaka, M.; Ishino, M.; Nishikino, M.; Kando, M.; Kato, Y.; Kawachi, T.

    2016-03-01

    There is a significant interest in developing the coherent table-top X-ray lasers. Advent of plasma-based transient collisional excitation x-ray laser and particular, injection of coherent seeded beam, especially high-order harmonics, has tremendously improved the spatial coherence of such lasers, what allowed them to be the same widely used as synchrotron sources. Here we report experimental founding of unknown interference structure in a spatial profile of the output beam of the two-stage plasma X-ray laser. That allowed us experimental and theoretical discovering a new phenomenon consisted in a generation of phase-matched coherent point source in a laser plasma media by propagated X-ray laser seeded beam. This phenomenon could extend the applications of such x-ray lasers. For explanation of the observed phenomenon a new method of solving the standard system of Maxwell-Bloch equations has been developed. It was found that the interference pattern in the output laser beam was formed due to an emergence of phase-matched coherent virtual point source in the XRL amplifier and could be treated as the first observation of mirage phenomenon, analogous to the optical mirage, but in X-rays. The obtained results bring new comprehension into the physical nature of amplification of X-ray radiation in laser-induced plasma amplifiers and opening new opportunities for X-ray interferometry, holography and other applications, which requiring multiple rigidly phased sources of coherent radiation.

  9. Registration of 2D x-ray images to 3D MRI by generating pseudo-CT data

    NASA Astrophysics Data System (ADS)

    van der Bom, M. J.; Pluim, J. P. W.; Gounis, M. J.; van de Kraats, E. B.; Sprinkhuizen, S. M.; Timmer, J.; Homan, R.; Bartels, L. W.

    2011-02-01

    Spatial and soft tissue information provided by magnetic resonance imaging can be very valuable during image-guided procedures, where usually only real-time two-dimensional (2D) x-ray images are available. Registration of 2D x-ray images to three-dimensional (3D) magnetic resonance imaging (MRI) data, acquired prior to the procedure, can provide optimal information to guide the procedure. However, registering x-ray images to MRI data is not a trivial task because of their fundamental difference in tissue contrast. This paper presents a technique that generates pseudo-computed tomography (CT) data from multi-spectral MRI acquisitions which is sufficiently similar to real CT data to enable registration of x-ray to MRI with comparable accuracy as registration of x-ray to CT. The method is based on a k-nearest-neighbors (kNN)-regression strategy which labels voxels of MRI data with CT Hounsfield Units. The regression method uses multi-spectral MRI intensities and intensity gradients as features to discriminate between various tissue types. The efficacy of using pseudo-CT data for registration of x-ray to MRI was tested on ex vivo animal data. 2D-3D registration experiments using CT and pseudo-CT data of multiple subjects were performed with a commonly used 2D-3D registration algorithm. On average, the median target registration error for registration of two x-ray images to MRI data was approximately 1 mm larger than for x-ray to CT registration. The authors have shown that pseudo-CT data generated from multi-spectral MRI facilitate registration of MRI to x-ray images. From the experiments it could be concluded that the accuracy achieved was comparable to that of registering x-ray images to CT data.

  10. Thermonuclear ignition by Z-pinch X-ray radiation produced by current of an explosive magnetic generator

    NASA Astrophysics Data System (ADS)

    Garanin, S. G.; Ivanovskiy, A. V.

    2015-12-01

    The scheme of a device based a superpower disk-type magnetic explosion generator to produce a pulse of X-ray radiation with the energy exceeding the target ignition threshold is described and validated.

  11. Thermonuclear ignition by Z-pinch X-ray radiation produced by current of an explosive magnetic generator

    SciTech Connect

    Garanin, S. G.; Ivanovskiy, A. V.

    2015-12-15

    The scheme of a device based a superpower disk-type magnetic explosion generator to produce a pulse of X-ray radiation with the energy exceeding the target ignition threshold is described and validated.

  12. Design study of compact Laser-Electron X-ray Generator for material and life sciences applications

    NASA Astrophysics Data System (ADS)

    Bessonov, E. G.; Gorbunkov, M. V.; Kostryukov, P. V.; Maslova, Yu Ya; Tunkin, V. G.; Postnov, A. A.; Mikhailichenko, A. A.; Shvedunov, V. I.; Ishkhanov, B. S.; Vinogradov, A. V.

    2009-07-01

    X-ray generators utilizing Thomson scattering fill in the gap that exists between conventional and synchrotron-based X-ray sources. They are expected to be more intensive than X-ray tubes and more compact, accessible and less expensive than synchrotrons. In this work, two operation modes of Thomson X-ray source (or laser-electron X-ray generator — LEXG) are documented: quasi continuous wave (QCW) and a pulsed one. They are considered for material sciences and medical applications that are currently implemented at Synchrotron Radiation (SR) facilities. The proposed system contains a ~ 50 MeV linac and a picosecond laser with an average power ~ few hundred Watts. The Thomson X-ray source is able to deliver up to 5 × 1011 photons in a millisecond flash and an average flux of 1012-1013 phot/sec. To achieve these parameters with existing optical and accelerator technology, the system must also contain a ring for storage of e-bunches for 103-105 revolutions and an optical circulator for storage of laser pulses for 102 passes. The XAFS spectroscopy, small animal angiography and human noninvasive coronary angiography are considered as possible applications of laser-electron X-ray generator.

  13. K-edge angiography utilizing a tungsten plasma X-ray generator in conjunction with gadolinium-based contrast media

    NASA Astrophysics Data System (ADS)

    Sato, Eiichi; Hayasi, Yasuomi; Tanaka, Etsuro; Mori, Hidezo; Kawai, Toshiaki; Inoue, Takashi; Ogawa, Akira; Sato, Shigehiro; Takayama, Kazuyoshi; Onagawa, Jun; Ido, Hideaki

    2006-11-01

    The tungsten plasma flash X-ray generator is useful in order to perform high-speed enhanced K-edge angiography using cone beams because K-series characteristic X-rays from the tungsten target are absorbed effectively by gadolinium-based contrast media. In the flash X-ray generator, a 150 nF condenser is charged up to 80 kV by a power supply, and flash X-rays are produced by the discharging. The X-ray tube is a demountable diode, and the turbomolecular pump evacuates air from the tube with a pressure of approximately 1 mPa. Since the electric circuit of the high-voltage pulse generator employs a cable transmission line, the high-voltage pulse generator produces twice the potential of the condenser charging voltage. At a charging voltage of 80 kV, the estimated maximum tube voltage and current were approximately 160 kV and 40 kA, respectively. When the charging voltage was increased, the characteristic X-ray intensities of tungsten K α lines increased. The K α lines were clean, and hardly any bremsstrahlung rays were detected. The X-ray pulse widths were approximately 110 ns, and the time-integrated X-ray intensity had a value of approximately 0.35 mGy at 1.0 m from the X-ray source with a charging voltage of 80 kV. Angiography was performed using a film-less computed radiography (CR) system and gadolinium-based contrast media. In angiography of non-living animals, we observed fine blood vessels of approximately 100 μm with high contrasts.

  14. Enhanced K-edge Angiography Utilizing Tantalum Plasma X-ray Generator in Conjunction with Gadolinium-Based Contrast Media

    NASA Astrophysics Data System (ADS)

    Sato, Eiichi; Hayasi, Yasuomi; Kimura, Koji; Tanaka, Etsuro; Mori, Hidezo; Kawai, Toshiaki; Inoue, Takashi; Ogawa, Akira; Sato, Shigehiro; Takayama, Kazuyoshi; Onagawa, Jun; Ido, Hideaki

    2005-12-01

    The tantalum plasma flash X-ray generator is useful for performing high-speed enhanced K-edge angiography using cone beams because K-series characteristic X-rays from the tantalum target are absorbed effectively by gadolinium-based contrast media. In the flash X-ray generator, a 150 nF condenser is charged up to 80 kV by a power supply, and flash X-rays are produced by the discharging. The X-ray tube is a demountable cold-cathode diode, and the turbomolecular pump evacuates air from the tube with a pressure of approximately 1 mPa. Since the electric circuit of the high-voltage pulse generator employs a cable transmission line, the high-voltage pulse generator produces twice the potential of the condenser charging voltage. At a charging voltage of 80 kV, the estimated maximum tube voltage and current were approximately 160 kV and 40 kA, respectively. When the charging voltage was increased, the K-series characteristic X-ray intensities of cerium increased. The K lines were clean and intense, and hardly any bremsstrahlung rays were detected. The X-ray pulse widths were approximately 100 ns, and the time-integrated X-ray intensity had a value of approximately 300 μGy at 1.0 m from the X-ray source with a charging voltage of 80 kV. Angiography was performed using a filmless computed radiography (CR) system and gadolinium-based contrast media. In the angiography of nonliving animals, we observed fine blood vessels of approximately 100 μm with high contrasts.

  15. A proposal for the generation of ultra-short x-ray pulses

    SciTech Connect

    Zholents, A.A.; Zolotorev, M.S.

    1994-08-01

    In this paper it is shown that optical stochastic cooling in a 150 MeV electron storage ring will allow production of a beam with longitudinal emittance 4.5 {times} 10{sup {minus}6} MeV{center_dot}m. Such a small emittance accompanied with a bunch compression technique based upon the transformation in the longitudinal phase space will allow achieving a bunch length 30 {mu}m. This bunch could then be used for the generation of ultra-short x-ray pulses by the Compton scattering of laser photons.

  16. Vacuum-Assisted Generation and Control of Atomic Coherences at X-Ray Energies

    NASA Astrophysics Data System (ADS)

    Heeg, Kilian P.; Wille, Hans-Christian; Schlage, Kai; Guryeva, Tatyana; Schumacher, Daniel; Uschmann, Ingo; Schulze, Kai S.; Marx, Berit; Kämpfer, Tino; Paulus, Gerhard G.; Röhlsberger, Ralf; Evers, Jörg

    2013-08-01

    The control of light-matter interaction at the quantum level usually requires coherent laser fields. But already an exchange of virtual photons with the electromagnetic vacuum field alone can lead to quantum coherences, which subsequently suppress spontaneous emission. We demonstrate such spontaneously generated coherences (SGC) in a large ensemble of nuclei operating in the x-ray regime, resonantly coupled to a common cavity environment. The observed SGC originates from two fundamentally different mechanisms related to cooperative emission and magnetically controlled anisotropy of the cavity vacuum. This approach opens new perspectives for quantum control, quantum state engineering and simulation of quantum many-body physics in an essentially decoherence-free setting.

  17. X-ray and electron generation in the relativistic lambda-cubed regime

    NASA Astrophysics Data System (ADS)

    Mordovanakis, Aghapi G.

    Over the last two decades, laser-plasma interactions at relativistic intensities have been carried out using large laser facilities producing at least several hundred millijoule pulses at a repetition rate of 10 Hz or lower. A less explored regime is when intensities in excess of 1018 W/cm2 are attained by focusing millijoule-level femtosecond pulses to a spot with a diameter comparable to the laser wavelength. This so-called relativistic lambda3 regime allows the study of certain laser-plasma experiments at kilohertz repetition rate. The present dissertation contributes to the understanding of the x-ray source and hot electrons produced in this regime. The micron-sized lambda3 focus engenders a comparably sized x-ray source that could be attractive for high resolution x-ray imaging applications. With this in mind, the source size is measured for various target materials using the knife-edge technique. Furthermore, the source spatial coherence properties are investigated by analyzing the diffraction pattern off a straight edge. Also investigated are the spatial and energy distributions of hot electrons escaping the plasma. In the case of an Al plasma, the electrons have a Maxwellian-like energy distribution with a temperature that scales with (I lambda 2)0.6 in the 1017--2 x 10 18 W/cm2 intensity range. On the other hand, in the case of an SiO2 plasma with lambda/2 scale-length, the electrons are emitted in a collimated relativistic jet having a non-Maxwellian distribution with = 675 keV. This is the first demonstration of laser-generated relativistic electron beams at kilohertz repetition rate. Additionally, this dissertation reports on two pioneering demonstrations in a related but fundamentally different regime, that of high-average power fiber lasers. In the first experiment, Ni Kalpha x-rays are produced using a fiber CPA system at the intensity of 2 x 1018 W/cm 2, the highest reported to date from a fiber system. The conversion efficiency into the Kalpha

  18. Measurement of the unstained biological sample by a novel scanning electron generation X-ray microscope based on SEM

    SciTech Connect

    Ogura, Toshihiko

    2009-08-07

    We introduced a novel X-ray microscope system based on scanning electron microscopy using thin film, which enables the measurement of unstained biological samples without damage. An unstained yeast sample was adsorbed under a titanium (Ti)-coated silicon nitride (Si{sub 3}N{sub 4}) film 90 nm thick. The X-ray signal from the film was detected by an X-ray photodiode (PD) placed below the sample. With an electron beam at 2.6 kV acceleration and 6.75 nA current, the yeast image is obtained using the X-ray PD. The image is created by soft X-rays from the Ti layer. The Ti layer is effective in generating the characteristic 2.7-nm wavelength X-rays by the irradiation of electrons. Furthermore, we investigated the electron trajectory and the generation of the characteristic X-rays within the Ti-coated Si{sub 3}N{sub 4} film by Monte Carlo simulation. Our system can be easily utilized to observe various unstained biological samples of cells, bacteria, and viruses.

  19. BEAM DYNAMICS STUDIES OF A HIGH-REPETITION RATE LINAC-DRIVER FOR A 4TH GENERATION LIGHT SOURCE

    SciTech Connect

    Ventturini, M.; Corlett, J.; Emma, P.; Papadopoulos, C.; Penn, G.; Placidi, M.; Qiang, J.; Reinsch, M.; Sannibale, F.; Steier, C.; Sun, C.; Wells, R.

    2012-05-18

    We present recent progress toward the design of a super-conducting linac driver for a high-repetition rate FEL-based soft x-ray light source. The machine is designed to accept beams generated by the APEX photo-cathode gun operating with MHz-range repetition rate and deliver them to an array of SASE and seeded FEL beamlines. We review the current baseline design and report results of beam dynamics studies.

  20. Common features of particle beams and x-rays generated in a low energy dense plasma focus device

    SciTech Connect

    Behbahani, R. A.; Xiao, C.

    2015-02-15

    Features of energetic charged particle beams and x-ray emission in a low energy (1–2 kJ) plasma focus (DPF) device are described and the possible mechanism are explained based on circuit analyses and energy balance in the DPF system. In particular, the resistance and the voltage across the plasma column are estimated to explain the mechanisms of the generation of particle beams and hard x-ray. The analysis shows that the total inductance of a DPF might have played a role for enhancement of the particle beams and x-ray emissions during the phase of anomalous resistance.

  1. Titanium-Dioxide Nano-Fiber-Cotton Targets for Efficient Multi-keV X-Ray Generation

    SciTech Connect

    Tanabe, M; Nishimura, H; Fujioka, S; Nagai, K; Yamamoto, N; Gu, Z; Pan, C; Girard, F; Primout, M; Villette, B; Brebion, D; Fournier, K B; Fujishima, A; Mima, K

    2008-06-12

    Multi-keV x-ray generation from low-density (27 {+-} 7 mg/cc) nano-fiber-cotton targets composed of titanium-dioxide has been investigated. The cotton targets were heated volumetrically and supersonically to a peak electron temperature of 2.3 keV, which is optimal to yield Ti K-shell x rays. Considerable enhancement of conversion efficiency (3.7 {+-} 0.5%) from incident laser energy into Ti K-shell x rays (4-6 keV band) was attained in comparison with that (1.4 {+-} 0.9%) for a planar Ti-foil target.

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

    NASA Astrophysics Data System (ADS)

    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.

  3. Scattered hard X-ray and γ-ray generation from a chromatic electron beam

    SciTech Connect

    Coleman, J. E.; Welch, D. R.; Miller, C. L.

    2015-11-14

    An array of photon diagnostics has been deployed on a high power relativistic electron beam diode. Electrons are extracted through a 17.8 cm diode from the surface discharge of a carbon fiber velvet cathode with a nominal diode voltage of 3.8 MV. <10% of the 100 ns electron pulse is composed of off energy electrons (1–3 MeV) accelerated during the rise and fall of the pulse that impact the stainless steel beam pipe and generate a Bremsstrahlung spectrum of 0.1–3 MeV photons with a total count of 10{sup 11}. The principal objective of these experiments is to quantify the electron beam dynamics and spatial dynamics of the hard X-ray and γ-ray flux generated in the diode region. A qualitative comparison of experimental and calculated results are presented, including time and energy resolved electron beam propagation and scattered photon measurements with X-ray PIN diodes and a photomultiplier tube indicating a dose dependence on the diode voltage >V{sup 4} and detected photon counts of nearly 10{sup 6} at a radial distance of 1 m which corresponds to dose ∼40 μrad at 1 m.

  4. Scattered hard X-ray and γ-ray generation from a chromatic electron beam

    NASA Astrophysics Data System (ADS)

    Coleman, J. E.; Welch, D. R.; Miller, C. L.

    2015-11-01

    An array of photon diagnostics has been deployed on a high power relativistic electron beam diode. Electrons are extracted through a 17.8 cm diode from the surface discharge of a carbon fiber velvet cathode with a nominal diode voltage of 3.8 MV. <10% of the 100 ns electron pulse is composed of off energy electrons (1-3 MeV) accelerated during the rise and fall of the pulse that impact the stainless steel beam pipe and generate a Bremsstrahlung spectrum of 0.1-3 MeV photons with a total count of 1011. The principal objective of these experiments is to quantify the electron beam dynamics and spatial dynamics of the hard X-ray and γ-ray flux generated in the diode region. A qualitative comparison of experimental and calculated results are presented, including time and energy resolved electron beam propagation and scattered photon measurements with X-ray PIN diodes and a photomultiplier tube indicating a dose dependence on the diode voltage >V4 and detected photon counts of nearly 106 at a radial distance of 1 m which corresponds to dose ˜40 μrad at 1 m.

  5. MOSFET dosimetry with high spatial resolution in intense synchrotron-generated x-ray microbeams

    SciTech Connect

    Siegbahn, E. A.; Braeuer-Krisch, E.; Bravin, A.; Nettelbeck, H.; Lerch, M. L. F.; Rosenfeld, A. B.

    2009-04-15

    Various dosimeters have been tested for assessing absorbed doses with microscopic spatial resolution in targets irradiated by high-flux, synchrotron-generated, low-energy ({approx}30-300 keV) x-ray microbeams. A MOSFET detector has been used for this study since its radio sensitive element, which is extraordinarily narrow ({approx}1 {mu}m), suits the main applications of interest, microbeam radiation biology and microbeam radiation therapy (MRT). In MRT, micrometer-wide, centimeter-high, and vertically oriented swaths of tissue are irradiated by arrays of rectangular x-ray microbeams produced by a multislit collimator (MSC). We used MOSFETs to measure the dose distribution, produced by arrays of x-ray microbeams shaped by two different MSCs, in a tissue-equivalent phantom. Doses were measured near the center of the arrays and maximum/minimum (peak/valley) dose ratios (PVDRs) were calculated to determine how variations in heights and in widths of the microbeams influenced this for the therapy, potentially important parameter. Monte Carlo (MC) simulations of the absorbed dose distribution in the phantom were also performed. The results show that when the heights of the irradiated swaths were below those applicable to clinical therapy (<1 mm) the MC simulations produce estimates of PVDRs that are up to a factor of 3 higher than the measured values. For arrays of higher microbeams (i.e., 25 {mu}mx1 cm instead of 25x500 {mu}m{sup 2}), this difference between measured and simulated PVDRs becomes less than 50%. Closer agreement was observed between the measured and simulated PVDRs for the Tecomet MSC (current collimator design) than for the Archer MSC. Sources of discrepancies between measured and simulated doses are discussed, of which the energy dependent response of the MOSFET was shown to be among the most important.

  6. MOSFET dosimetry with high spatial resolution in intense synchrotron-generated x-ray microbeams.

    PubMed

    Siegbahn, E A; Bräuer-Krisch, E; Bravin, A; Nettelbeck, H; Lerch, M L F; Rosenfeld, A B

    2009-04-01

    Various dosimeters have been tested for assessing absorbed doses with microscopic spatial resolution in targets irradiated by high-flux, synchrotron-generated, low-energy (approximately 30-300 keV) x-ray microbeams. A MOSFET detector has been used for this study since its radio sensitive element, which is extraordinarily narrow (approximately 1 microm), suits the main applications of interest, microbeam radiation biology and microbeam radiation therapy (MRT). In MRT, micrometer-wide, centimeter-high, and vertically oriented swaths of tissue are irradiated by arrays of rectangular x-ray microbeams produced by a multislit collimator (MSC). We used MOSFETs to measure the dose distribution, produced by arrays of x-ray microbeams shaped by two different MSCs, in a tissue-equivalent phantom. Doses were measured near the center of the arrays and maximum/minimum (peak/valley) dose ratios (PVDRs) were calculated to determine how variations in heights and in widths of the microbeams influenced this for the therapy, potentially important parameter. Monte Carlo (MC) simulations of the absorbed dose distribution in the phantom were also performed. The results show that when the heights of the irradiated swaths were below those applicable to clinical therapy (< 1 mm) the MC simulations produce estimates of PVDRs that are up to a factor of 3 higher than the measured values. For arrays of higher microbeams (i.e., 25 microm x 1 cm instead of 25 x 500 microm2), this difference between measured and simulated PVDRs becomes less than 50%. Closer agreement was observed between the measured and simulated PVDRs for the Tecomet MSC (current collimator design) than for the Archer MSC. Sources of discrepancies between measured and simulated doses are discussed, of which the energy dependent response of the MOSFET was shown to be among the most important. PMID:19472618

  7. Single-hit spectroscopy of betatron X-ray spectra generated by laser wakefield acceleration using self and ionization injection

    NASA Astrophysics Data System (ADS)

    Condamine, Florian; Schumaker, Will; Kotick, Jordan; Albert, Felicie; Barbrel, Benjamin; Galtier, Eric; Granados, Eduardo; Ravasio, Alessandra; Fry, Alan; Glenzer, Siegfried

    2015-11-01

    Betatron X-ray created by laser wakefield acceleration (LWFA) are of fundamental interest in plasma physics due to their broadband X-ray spectra, compact source size and ultra short duration. In particular, the femtosecond duration of electrons bunches produced during LWFA offers the opportunity to study warm dense matter (WDM) in detail via pump/probe experiments. In this study, we used the SLAC MEC optical laser (Ti:S 800nm, 1J in 40fs) focused in a gas cell to generate betatron X-ray by using two LWFA techniques : self-injection and ionization-injection. Three different gas types (100%, 98% and 90% helium, doped with nitrogen) were investigated using a single hit detector to characterize X-ray spectra generated by the betatron source. We will compare results with self-injection and ionization-injection for different plasma conditions and several positions of the laser focal spot inside the gas cell.

  8. Investigation of gas generation in regenerative fuel cells by low-energy X-rays

    NASA Astrophysics Data System (ADS)

    Selamet, Omer Faruk; Deevanhxay, Phengxay; Tsushima, Shohji; Hirai, Shuichiro

    2015-11-01

    Gas generation and discharge behaviors in an operating regenerative fuel cell (RFC) are investigated using low-energy X-ray radiography. In situ visualization at high spatial and temporal resolution reveal dynamic and inhomogeneous behaviors of the gas generation in the membrane electrode assembly (MEA) in the RFC. Temporal and spatial variation of the gas thickness in the MEA is quantitatively discussed and shows an intermittent and periodic discharge processes of the gas generated by electrolysis, suggesting that the reaction sites in the catalyst layer and the discharging path of gas bubbles are well established in the MEA for the electrolysis. Larger gas accumulation and discharge in the gas diffusion layer (GDL) under the ribs are identified in comparison with those under the channels, which is attributed to the relatively longer path for accumulated gas under the ribs to be discharged into the flow channels.

  9. Moving-Article X-Ray Imaging System and Method for 3-D Image Generation

    NASA Technical Reports Server (NTRS)

    Fernandez, Kenneth R. (Inventor)

    2012-01-01

    An x-ray imaging system and method for a moving article are provided for an article moved along a linear direction of travel while the article is exposed to non-overlapping x-ray beams. A plurality of parallel linear sensor arrays are disposed in the x-ray beams after they pass through the article. More specifically, a first half of the plurality are disposed in a first of the x-ray beams while a second half of the plurality are disposed in a second of the x-ray beams. Each of the parallel linear sensor arrays is oriented perpendicular to the linear direction of travel. Each of the parallel linear sensor arrays in the first half is matched to a corresponding one of the parallel linear sensor arrays in the second half in terms of an angular position in the first of the x-ray beams and the second of the x-ray beams, respectively.

  10. A bright attosecond x-ray pulse train generation in a double-laser-driven cone target

    NASA Astrophysics Data System (ADS)

    Hu, Li-Xiang; Yu, Tong-Pu; Shao, Fu-Qiu; Luo, Wen; Yin, Yan

    2016-06-01

    By using full three-dimensional particle-in-cell and Monte Carlo simulations, we investigate the generation of a high-brightness attosecond x-ray pulse train in a double-laser-driven cone target. The scheme makes use of two lasers: the first high-intensity laser with a laser peak intensity 1.37 × 1020 W/cm2 irradiates the cone and produces overdense attosecond electron bunches; the second counterpropagating weakly relativistic laser with a laser peak intensity 4.932 × 1017 W/cm2 interacts with the produced electron bunches and a bright x-ray pulse train is generated by Thomson backscattering of the second laser off the attosecond electron bunches. It is shown that the photon flux rises by 5 times using the cone target as compared with a normal channel. Meanwhile, the x-ray peak brightness increases significantly from 1.4 × 1021/(s mm2 mrad2 0.1 keV) to 6.0 × 1021/(s mm2 mrad2 0.1 keV), which is much higher than that of the Thomson x-ray source generated from traditional accelerators. We also discuss the influence of the laser and target parameters on the x-ray pulse properties. This compact bright x-ray source may have diverse applications, e.g., the study of electric dynamics and harmonics emission in the atomic scale.

  11. THE NEXT GENERATION ATLAS OF QUASAR SPECTRAL ENERGY DISTRIBUTIONS FROM RADIO TO X-RAYS

    SciTech Connect

    Shang Zhaohui; Li Jun; Xie Yanxia; Brotherton, Michael S.; Cales, Sabrina L.; Dale, Daniel A.; Runnoe, Jessie C.; Kelly, Benjamin J.; Wills, Beverley J.; Wills, D.; Green, Richard F.; Nemmen, Rodrigo S.; Ganguly, Rajib; Hines, Dean C.; Kriss, Gerard A.; Tang, Baitian

    2011-09-01

    We have produced the next generation of quasar spectral energy distributions (SEDs), essentially updating the work of Elvis et al. by using high-quality data obtained with several space- and ground-based telescopes, including NASA's Great Observatories. We present an atlas of SEDs of 85 optically bright, non-blazar quasars over the electromagnetic spectrum from radio to X-rays. The heterogeneous sample includes 27 radio-quiet and 58 radio-loud quasars. Most objects have quasi-simultaneous ultraviolet-optical spectroscopic data, supplemented with some far-ultraviolet spectra, and more than half also have Spitzer mid-infrared Infrared Spectrograph spectra. The X-ray spectral parameters are collected from the literature where available. The radio, far-infrared, and near-infrared photometric data are also obtained from either the literature or new observations. We construct composite SEDs for radio-loud and radio-quiet objects and compare these to those of Elvis et al., finding that ours have similar overall shapes, but our improved spectral resolution reveals more detailed features, especially in the mid- and near-infrared.

  12. Constraining high-redshift X-ray sources with next generation 21-cm power spectrum measurements

    NASA Astrophysics Data System (ADS)

    Ewall-Wice, Aaron; Hewitt, Jacqueline; Mesinger, Andrei; Dillon, Joshua S.; Liu, Adrian; Pober, Jonathan

    2016-05-01

    We use the Fisher matrix formalism and seminumerical simulations to derive quantitative predictions of the constraints that power spectrum measurements on next-generation interferometers, such as the Hydrogen Epoch of Reionization Array (HERA) and the Square Kilometre Array (SKA), will place on the characteristics of the X-ray sources that heated the high-redshift intergalactic medium. Incorporating observations between z = 5 and 25, we find that the proposed 331 element HERA and SKA phase 1 will be capable of placing ≲ 10 per cent constraints on the spectral properties of these first X-ray sources, even if one is unable to perform measurements within the foreground contaminated `wedge' or the FM band. When accounting for the enhancement in power spectrum amplitude from spin temperature fluctuations, we find that the observable signatures of reionization extend well beyond the peak in the power spectrum usually associated with it. We also find that lower redshift degeneracies between the signatures of heating and reionization physics lead to errors on reionization parameters that are significantly greater than previously predicted. Observations over the heating epoch are able to break these degeneracies and improve our constraints considerably. For these two reasons, 21-cm observations during the heating epoch significantly enhance our understanding of reionization as well.

  13. The Next Generation Atlas of Quasar Spectral Energy Distributions from Radio to X-Rays

    NASA Astrophysics Data System (ADS)

    Shang, Zhaohui; Brotherton, Michael S.; Wills, Beverley J.; Wills, D.; Cales, Sabrina L.; Dale, Daniel A.; Green, Richard F.; Runnoe, Jessie C.; Nemmen, Rodrigo S.; Gallagher, Sarah C.; Ganguly, Rajib; Hines, Dean C.; Kelly, Benjamin J.; Kriss, Gerard A.; Li, Jun; Tang, Baitian; Xie, Yanxia

    2011-09-01

    We have produced the next generation of quasar spectral energy distributions (SEDs), essentially updating the work of Elvis et al. by using high-quality data obtained with several space- and ground-based telescopes, including NASA's Great Observatories. We present an atlas of SEDs of 85 optically bright, non-blazar quasars over the electromagnetic spectrum from radio to X-rays. The heterogeneous sample includes 27 radio-quiet and 58 radio-loud quasars. Most objects have quasi-simultaneous ultraviolet-optical spectroscopic data, supplemented with some far-ultraviolet spectra, and more than half also have Spitzer mid-infrared Infrared Spectrograph spectra. The X-ray spectral parameters are collected from the literature where available. The radio, far-infrared, and near-infrared photometric data are also obtained from either the literature or new observations. We construct composite SEDs for radio-loud and radio-quiet objects and compare these to those of Elvis et al., finding that ours have similar overall shapes, but our improved spectral resolution reveals more detailed features, especially in the mid- and near-infrared.

  14. Flexible Field Emitter for X-ray Generation by Implanting CNTs into Nickel Foil

    NASA Astrophysics Data System (ADS)

    Sun, Bin; Wang, Yan; Ding, Guifu

    2016-07-01

    This paper reports a novel implanting micromachining technology. By using this method, for the first time, we could implant nano-scale materials into milli-scale metal substrates at room temperature. Ni-based flexible carbon nanotube (CNT) field emitters were fabricated by the novel micromachining method. By embedding CNT roots into Ni foil using polymer matrix as transfer media, effective direct contact between Ni and CNTs was achieved. As a result, our novel emitter shows relatively good field emission properties such as low turn-on field and good stability. Moreover, the emitter was highly flexible with preservation of the field emission properties. The excellent field emission characteristics attributed to the direct contact and the strong interactions between CNTs and the substrate. To check the practical application of the novel emitter, a simple X-ray imaging system was set up by modifying a traditional tube. The gray shadow that appears on the sensitive film after being exposed to the radiation confirms the successful generation of X-ray.

  15. Flexible Field Emitter for X-ray Generation by Implanting CNTs into Nickel Foil.

    PubMed

    Sun, Bin; Wang, Yan; Ding, Guifu

    2016-12-01

    This paper reports a novel implanting micromachining technology. By using this method, for the first time, we could implant nano-scale materials into milli-scale metal substrates at room temperature. Ni-based flexible carbon nanotube (CNT) field emitters were fabricated by the novel micromachining method. By embedding CNT roots into Ni foil using polymer matrix as transfer media, effective direct contact between Ni and CNTs was achieved. As a result, our novel emitter shows relatively good field emission properties such as low turn-on field and good stability. Moreover, the emitter was highly flexible with preservation of the field emission properties. The excellent field emission characteristics attributed to the direct contact and the strong interactions between CNTs and the substrate. To check the practical application of the novel emitter, a simple X-ray imaging system was set up by modifying a traditional tube. The gray shadow that appears on the sensitive film after being exposed to the radiation confirms the successful generation of X-ray. PMID:27401089

  16. Generation-X mirror technology development plan and the development of adjustable x-ray optics

    NASA Astrophysics Data System (ADS)

    Reid, Paul B.; Davis, William; O'Dell, Stephen; Schwartz, Daniel A.; Tolier-McKinstry, Susan; Wilke, Rudeger H. T.; Zhang, William

    2009-08-01

    Generation-X is being studied as an extremely high resolution, very large area grazing incidence x-ray telescope. Under a NASA Advanced Mission Concepts Study, we have developed a technology plan designed to lead to the 0.1 arcsec (HPD) resolution adjustable optics with 50 square meters of effective area necessary to meet Generation-X requirements. We describe our plan in detail. In addition, we report on our development activities of adjustable grazing incidence optics via the fabrication of bimorph mirrors. We have successfully deposited thin-film piezo-electric material on the back surface of thin glass mirrors. We report on the electrical and mechanical properties of the bimorph mirrors. We also report on initial finite element modeling of adjustable grazing incidence mirrors; in particular, we examine the impact of how the mirrors are supported - the boundary conditions - on the deformations which can be achieved.

  17. Evidence of High Harmonics from Echo-Enabled Harmonic Generation for Seeding X-ray Free Electron Lasers

    SciTech Connect

    Xiang, D.; Colby, E.; Dunning, M.; Gilevich, S.; Hast, C.; Jobe, K.; McCormick, D.; Nelson, J.; Raubenheimer, T.O.; Soong, K.; Stupakov, G.; Szalata, Z.; Walz, D.; Weathersby, S.; Woodle, M.; /SLAC

    2012-02-15

    Echo-enabled harmonic generation free electron lasers hold great promise for the generation of fully coherent radiation in x-ray wavelengths. Here we report the first evidence of high harmonics from the echo-enabled harmonic generation technique in the realistic scenario where the laser energy modulation is comparable to the beam slice energy spread. In this experiment, coherent radiation at the seventh harmonic of the second seed laser is generated when the energy modulation amplitude is about 2-3 times the slice energy spread. The experiment confirms the underlying physics of echo-enabled harmonic generation and may have a strong impact on emerging seeded x-ray free electron lasers that are capable of generating laserlike x rays which will advance many areas of science.

  18. A triboelectric closed loop band system for the generation of x-rays

    NASA Astrophysics Data System (ADS)

    Van Cleve, E.; Lucas, B.; Ganlieli, Z.; Wong, E. W.; Cortes, P.; Mehta, N.; Cuadra, D.; Fong, J.; Hansen, S.; Kotowski, A.; Camara, C. G.

    2015-08-01

    X-ray have been commercially produced using the same basic design since their discovery by Wilhelm Roentgen in 1895, for which he was awarded the first Nobel prize in physics. This technology requires high voltage elements, ultra high vacuum tubes, and high voltage electronics. The vacuum and high voltage drive up the price of x-ray technology and in order to bring down the cost, a brand new way to produce x-rays is needed. In 2008 Carlos Camara, Juan Escobar, Jonathan R. Hird, and Seth Putterman1 discovered that by pealing scotch tape in a vacuum you could create enough x-rays to take an x-ray radiograph of a finger. This lead to the formation of Tribogenics and the development of the rod and band x-ray architecture.

  19. Next Generation Astronomical X-ray Optics: High Angular Resolution, Light Weight, and Low Production Cost

    NASA Technical Reports Server (NTRS)

    Zhang. W. W.; Biskach, M. P.; Blake, P. N.; Chan, K. W.; Gaskin, J. A.; Hong, M. L.; Jones, W. D.; Kolos, L. D.; Mazzarella, J. R.; McClelland, R. S.; O'Dell, S. L.; Saha, T. T.; Sharpe, M. V.

    2012-01-01

    X-ray astronomy depends on the availability of telescopes with high resolution and large photon collecting areas. Since x-ray observation can only be carried out above the atmosphere, these telescopes must be necessarily lightweight. Compounding the lightweight requirement is that an x-ray telescope consists of many nested concentric shells, which further require that x-ray mirrors must also be geometrically thin to achieve high packing efficiency. This double lightweight and geometrically thin requirement poses significant technical challenges in fabricating the mirrors and in integrating them into mirror assemblies. This paper reports on the approach, strategy and status of our x-ray optics development program whose objective is to meet these technical challenges at modest cost to enable future x-ray missions, including small Explorer missions in the near term, probe class missions in the medium term, and large flagship missions in the long term.

  20. The X-ray properties of normal galaxies. What do we know and what can we learn with the next generation of X-ray telescopes?. [spaceborne telescope

    NASA Technical Reports Server (NTRS)

    Fabbiano, G.

    1985-01-01

    Einstein Observatory results are used to assess the possibilities of spaceborne X-ray astronomy projects such as XMM (ESA) and AXAF (NASA). Einstein observations show that normal galaxies of all morphological types are spatially extended sources of X-ray emission with 0.5 to 3.0 keV X-ray luminosities of 10 to the 39th to 41st power erg/sec. X-ray telescopes can study the end products of stellar evolution in galaxies of different morphological types. Phenomena linked to starburst nuclear activity can best be detected and studied in X-ray. Hot coronae or a hot phase of the interstellar medium can only be studied through their X-ray emission. It is shown that high spatial resolution is essential for studying normal galaxies and identifying different emission regions. Good spectral sensitivity and spectral imaging capability are essential for gaining a deeper understanding of the phenomena at work.

  1. Requirements for use of nonmedical x-ray generators at SLAC

    SciTech Connect

    Busick, D.D.

    1984-09-01

    The risks associated with use of x-ray equipment have long been recognized. While the relative frequency of x-ray damage is small, machine produced x-rays and large radiography sources continue to account for a large percentage of preventable radiation injuries reported worldwide. The intent of this report is to formalize SLAC's radiation safety program as it applies to radiation producing equipment (diffraction, fluorescence analysis and nondestructive testing). It does not apply to the two-mile linac, experimental areas or other x-ray producing equipment directly related to the high energy physics program. 4 refs., 3 figs., 1 tab.

  2. Directional properties of hard x-ray sources generated by tightly focused ultrafast laser pulses

    SciTech Connect

    Hou Bixue; Mordovanakis, Aghapi; Easter, James; Krushelnick, Karl; Nees, John A.

    2008-11-17

    Directional properties of ultrafast laser-based hard x-ray sources are experimentally studied using tightly focused approximately millijoule laser pulses incident on a bulk Mo target. Energy distributions of K{alpha} and total x rays, as well as source-size distributions are directionally resolved in vacuum and in flowing helium, respectively. Directional distributions of x-ray emission is more isotropic for p-polarized pump than for s-polarized. Based on source-size measurements, a simple two-location model, with expanded plasma and bulk material, is employed to represent the x-ray source profile.

  3. Generation of strongly coupled Xe cluster nanoplasmas by low intensive soft x-ray laser irradiation

    SciTech Connect

    Namba, S.; Hasegawa, N.; Kishimoto, M.; Nishikino, M.; Kawachi, T.

    2012-07-11

    A seeding gas jet including Xe clusters was irradiated with a laser-driven plasma soft x-ray laser pulse ({lambda}=13.9 nm, {approx}7 ps, {<=}5 Multiplication-Sign 10{sup 9} W/cm{sup 2}), where the laser photon energy is high enough to ionize 4d core electrons. In order to clarify how the innershell ionization followed by the Auger electron emission is affected under the intense laser irradiation, the electron energy distribution was measured. Photoelectron spectra showed that the peak position attributed to 4d hole shifted to lower energy and the spectral width was broadened with increasing cluster size. Moreover, the energy distribution exhibited that a strongly coupled cluster nanoplasma with several eV was generated.

  4. Generation of intense coherent attosecond X-ray pulses using relativistic electron mirrors

    NASA Astrophysics Data System (ADS)

    Kulagin, V. V.; Kornienko, V. N.; Cherepenin, Vladimir A.; Suk, Hyyong

    2013-05-01

    We analyse the steepening of the leading edge of femtosecond petawatt pulses with the use of plasma layers and show that, at an electron density several times higher than the critical one, an asymmetric (in time domain) pulse can be produced with an amplitude of the first half-wave differing little from the maximum pulse amplitude. Using numerical simulation, we have studied the interaction of such pulses with nanometre-thick films, including the generation of relativistic electron mirrors and the reflection of a counterpropagating probe pulse from such mirrors. The resulting coherent X-ray pulses have a duration of ~120 as and a power of ~600 GW at a wavelength of ~13 nm. Our results demonstrate that the reflectivity of a relativistic electron mirror situated in the accelerating pulse field is independent of the probe pulse amplitude when it increases up to the accelerating pulse amplitude.

  5. Generation of X-ray radiation during planar channeling of relativistic electrons in crystals

    NASA Astrophysics Data System (ADS)

    Bashmakov, Yu. A.; Bondarenko, T. V.; Polozov, S. M.

    2016-07-01

    A classical model of the emission of radiation by relativistic electrons in a crystal has been developed using the form of the potential maximally close to its actual form. The dynamics of electrons with energies 20-25 MeV performing channeling in crystals is simulated numerically. The generation of electromagnetic radiation that accompanies this motion has been considered. It has been shown that, in the given electron energy range, this radiation corresponds to the X-ray spectral band with characteristic photon energies of up to 40 keV. The radiation yield is estimated. The requirements to the electron beam parameters are formulated based on the results of the simulation. It has been shown that numerical simulation gives results that correlate with the analytic results obtained earlier and with the experimental data.

  6. Superconducting RF Deflecting Cavity Design and Prototype for Short X-ray Pulse Generation

    SciTech Connect

    Shi, Jiaru; Chen, H.; Tang, C.-X.; Cheng, Guangfeng; Ciovati, Gianluigi; Kneisel, Peter; Rimmer, Robert; Slack, Gary; Turlington, Larry; Wang, Haipeng; Li, D.; Nassiri, Alireza; Waldschmidt, G.J.

    2008-07-01

    Deflecting RF cavities are proposed to be used in generating short x-ray pulses (on ~1-picosecond order) at the Advanced Photon Source (APS) at Argonne National Laboratory (ANL)* using a novel scheme by Zholents**. To meet the required deflecting voltage, impedance budget from higher order, lower order and the same order modes (HOM, LOM and SOM) of the APS storage ring, extensive deflecting cavity design studies have been conducted with numerical simulations and cavity prototypes. In this paper, we report recent progress on a single cell S-band (2.8-GHz) superconducting deflecting cavity design with waveguide damping. A copper and a niobium prototype cavity were fabricated and tested, respectively to benchmark the cavity and damping designs. A new damping scheme has been proposed which provides stronger damping to both HOM and LOM by directly coupling to a damping waveguide on the cavity equator.

  7. Rescattering effects in soft-x-ray generation by laser-assisted electron-ion recombination

    NASA Astrophysics Data System (ADS)

    Milošević, Dejan B.; Ehlotzky, Fritz

    2002-04-01

    Laser-assisted electron-ion recombination is investigated with an emphasis on the spectrum of the emitted high-energy photons and its modification due to the recollision of the incident electron and the ion. Numerical results for the soft-x-ray power spectra, added up over all intermediate laser photon channels, are presented as a function of the incident electron energy for different laser field intensities. For strong laser fields, maxima, and additional structures are found in these spectra for incident electron energies of the order of magnitude of the ponderomotive energy. We show that the laser-assisted electron-ion recombination, that includes the rescattering of the electron at the ion before the recombination, is a process complementary to the well-known processes of high-order harmonic generation and high-order above-threshold ionization. All these processes can be explained, using the three-step scenario. A semiclassical analysis is presented which shows that for the laser-assisted electron-ion recombination real solutions of the saddle-point equations exist, contrary to what is found with high-order harmonic generation and high-order above-threshold ionization when only complex solutions are permitted. For low incoming electron energies, the cutoff of the emitted soft-x-ray photon energies, including the process of rescattering, is higher than in the case of the direct recombination process. The height of the rescattering plateau is 6-7 orders of magnitude lower than that of the direct process. However, for higher incident electron energies we obtain the unexpected result that the difference between the height of the rescattering plateau and the height of the direct plateau can be less than one order of magnitude.

  8. Intense high repetition rate Mo Kα x-ray source generated from laser solid interaction for imaging application

    SciTech Connect

    Huang, K.; Li, M. H.; Yan, W. C.; Ma, Y.; Zhao, J. R.; Li, Y. F.; Chen, L. M.; Guo, X.; Li, D. Z.; Chen, Y. P.; Zhang, J.

    2014-11-15

    We report an efficient Mo Kα x-ray source produced by interaction of femtosecond Ti: sapphire laser pulses with a solid Molybdenum target working at 1 kHz repetition rate. The generated Mo Kα x-ray intensity reaches to 4.7 × 10{sup 10} photons sr{sup −1} s{sup −1}, corresponding to an average power of 0.8 mW into 2π solid angle. The spatial resolution of this x-ray source is measured to be 26 lp/mm. With the high flux and high spatial resolution characteristics, high resolving in-line x-ray radiography was realized on test objects and large size biological samples within merely half a minute. This experiment shows the possibility of laser plasma hard x-ray source as a new low cost and high resolution system for radiography and its ability of ultrafast x-ray pump-probe study of matter.

  9. Real-time observation of coherent acoustic phonons generated by an acoustically mismatched optoacoustic transducer using x-ray diffraction

    SciTech Connect

    Persson, A. I. H.; Andreasson, B. P.; Enquist, H.; Jurgilaitis, A.; Larsson, J.

    2015-11-14

    The spectrum of laser-generated acoustic phonons in indium antimonide coated with a thin nickel film has been studied using time-resolved x-ray diffraction. Strain pulses that can be considered to be built up from coherent phonons were generated in the nickel film by absorption of short laser pulses. Acoustic reflections at the Ni–InSb interface leads to interference that strongly modifies the resulting phonon spectrum. The study was performed with high momentum transfer resolution together with high time resolution. This was achieved by using a third-generation synchrotron radiation source that provided a high-brightness beam and an ultrafast x-ray streak camera to obtain a temporal resolution of 10 ps. We also carried out simulations, using commercial finite element software packages and on-line dynamic diffraction tools. Using these tools, it is possible to calculate the time-resolved x-ray reflectivity from these complicated strain shapes. The acoustic pulses have a peak strain amplitude close to 1%, and we investigated the possibility to use this device as an x-ray switch. At a bright source optimized for hard x-ray generation, the low reflectivity may be an acceptable trade-off to obtain a pulse duration that is more than an order of magnitude shorter.

  10. DETECTION OF A COOL, ACCRETION-SHOCK-GENERATED X-RAY PLASMA IN EX LUPI DURING THE 2008 OPTICAL ERUPTION

    SciTech Connect

    Teets, William K.; Weintraub, David A.; Kastner, Joel H.; Richmond, Michael; Grosso, Nicolas; Hamaguchi, Kenji

    2012-11-20

    EX Lupi is the prototype for a class of young, pre-main-sequence stars which are observed to undergo irregular, presumably accretion-generated, optical outbursts that result in a several magnitude rise of the optical flux. EX Lupi was observed to optically erupt in 2008 January, triggering Chandra ACIS Target of Opportunity observations shortly thereafter. We find very strong evidence that most of the X-ray emission in the first few months after the optical outburst is generated by accretion of circumstellar material onto the stellar photosphere. Specifically, we find a strong correlation between the decreasing optical and X-ray fluxes following the peak of the outburst in the optical, which suggests that these observed declines in both the optical and X-ray fluxes are the result of declining accretion rate. In addition, in our models of the X-ray spectrum, we find strong evidence for a {approx}0.4 keV plasma component, as expected for accretion shocks on low-mass, pre-main-sequence stars. From 2008 March through October, this cool plasma component appeared to fade as EX Lupi returned to its quiescent level in the optical, consistent with a decrease in the overall emission measure of accretion-shock-generated plasma. The overall small increase of the X-ray flux during the optical outburst of EX Lupi is similar to what was observed in previous X-ray observations of the 2005 optical outburst of the EX Lupi-type star V1118 Ori but contrasts with the large increase of the X-ray flux from the erupting young star V1647 Ori during its 2003 and 2008 optical outbursts.

  11. Detection of a Cool, Accretion-Shock-Generated X-Ray Plasma in EX Lupi During the 2008 Optical Eruption

    NASA Technical Reports Server (NTRS)

    Teets, William K.; Weintraub, David A.; Kastner, Joel H.; Grosso, Nicholas; Hamaguchi, Kenji; Richmond, Michael

    2012-01-01

    EX Lupi is the prototype for a class of young, pre-main-sequence stars which are observed to undergo irregular, presumably accretion-generated, optical outbursts that result in a several magnitude rise of the optical flux. EX Lupi was observed to optically erupt in 2008 January, triggering Chandra ACIS Target of Opportunity observations shortly thereafter. We find very strong evidence that most of the X-ray emission in the first few months after the optical outburst is generated by accretion of circumstellar material onto the stellar photosphere. Specifically, we find a strong correlation between the decreasing optical and X-ray fluxes following the peak of the outburst in the optical, which suggests that these observed declines in both the optical and X-ray fluxes are the result of declining accretion rate. In addition, in our models of the X-ray spectrum, we find strong evidence for an approx 0.4 keV plasma component, as expected for accretion shocks on low-mass, pre-main-sequence stars. From 2008 March through October, this cool plasma component appeared to fade as EX Lupi returned to its quiescent level in the optical, consistent with a decrease in the overall emission measure of accretion-shock-generated plasma. The overall small increase of the X-ray flux during the optical outburst of EX Lupi is similar to what was observed in previous X-ray observations of the 2005 optical outburst of the EX Lupi-type star V1118 Ori but contrasts with the large increase of the X-ray flux from the erupting young star V1647 Ori during its 2003 and 2008 optical outbursts.

  12. Studies of the Origin of High-frequency Quasi-periodic Oscillations of Mass-accreting Black Holes in X-Ray Binaries with Next-generation X-Ray Telescopes

    NASA Astrophysics Data System (ADS)

    Beheshtipour, Banafsheh; Hoormann, Janie K.; Krawczynski, Henric

    2016-08-01

    Observations with RXTE (Rossi X-ray Timing Explorer) revealed the presence of high-frequency quasi-periodic oscillations (HFQPOs) of the X-ray flux from several accreting stellar-mass black holes. HFQPOs (and their counterparts at lower frequencies) may allow us to study general relativity in the regime of strong gravity. However, the observational evidence today does not yet allow us to distinguish between different HFQPO models. In this paper we use a general-relativistic ray-tracing code to investigate X-ray timing spectroscopy and polarization properties of HFQPOs in the orbiting Hotspot model. We study observational signatures for the particular case of the 166 Hz quasi-periodic oscillation (QPO) in the galactic binary GRS 1915+105. We conclude with a discussion of the observability of spectral signatures with a timing-spectroscopy experiment such as the LOFT (Large Observatory for X-ray Timing) and polarization signatures with space-borne X-ray polarimeters such as IXPE (Imaging X-ray Polarimetry Explorer), PolSTAR (Polarization Spectroscopic Telescope Array), PRAXyS(Polarimetry of Relativistic X-ray Sources), or XIPE (X-ray Imaging Polarimetry Explorer). A mission with high count rate such as LOFT would make it possible to get a QPO phase for each photon, enabling the study of the QPO-phase-resolved spectral shape and the correlation between this and the flux level. Owing to the short periods of the HFQPOs, first-generation X-ray polarimeters would not be able to assign a QPO phase to each photon. The study of QPO-phase-resolved polarization energy spectra would thus require simultaneous observations with a first-generation X-ray polarimeter and a LOFT-type mission.

  13. Fundamental Study on a Long-Duration Flash X-Ray Generator with a Surface-Discharge Triode

    NASA Astrophysics Data System (ADS)

    Takahashi, Kei; Sato, Eiichi; Sagae, Michiaki; Oizumi, Teiji; Tamakawa, Yoshiharu; Yanagisawa, Toru

    1994-07-01

    Fundamental studies on a long-duration flash X-ray generator are described. This generator consisted of the following components: a high-voltage power supply with a maximum voltage of 100 kV, an energy-storage condenser of 500 nF, a main discharge condenser of 10 nF, a turbo molecular pump, a thyratron pulser as a trigger device, and a surface-discharge triode. The effective pulse width was less than 30 µs, and the X-ray intensity approximately had a value of 0.6 µC/kg at 1.0 m per pulse with a charged voltage of 60 kV. The maximum tube voltage was equivalent to the initial charged voltage of the condenser, and the peak tube current was less than 40 A. With this generator, we could obtain stable X-ray intensity maximized by preventing damped oscillations of the tube voltage and current.

  14. Beam characterization of a lab bench cold cathode ultra-soft X-ray generator

    NASA Astrophysics Data System (ADS)

    Ounoughi, N.; Mavon, C.; Belafrites, A.; Groetz, J.-E.; Fromm, M.

    2013-06-01

    The aim of this work is to characterize the Ultra Soft X-ray (USX, 1.5 keV, Al Kα) photon beam of a customized lab bench cold cathode generator. Within this generator, the electron beam is slowed down in a thin aluminium foil (16 μm) supported by an easily exchangeable anode. It is shown that the thickness of the foil and the anode configuration determine the spatial distribution and the fluence rate of the photon beam, whereas accelerating voltage determines both fluence rate and energy spectrum feature. It is shown also that under specific operation parameters (i.e. accelerating voltage), a Gaussian energy distribution of the beam can be generated which is centred on the energy of the Al Kα line (1.5 keV). Dosimetric films of GAFCHROMIC® HD-810 were used to estimate the photon fluence rate distribution of the beam. Its variation, when the generator acts as a monoenergetic source, was characterized with the two different configurations of the anode assembly. Finally, it is verified that the anode assembly consisting in a flat washer, on which the aluminium foil is set, acts as a simple point-source.

  15. High-gain harmonic generation of soft X-rays with the `fresh bunch` technique

    SciTech Connect

    Yu, Li-Hua; Ben-Zvi, I.

    1996-10-01

    We report numerical simulations (using the TDA code) and analytic verification of the generation of 64 {Angstrom} high power soft X- rays from an exponential regime single pass seeded FEL. The seed is generated in the FEL using the High Gain Harmonic Generation (HGHG) technique combined with the `Fresh bunch` technique. A seed pulse at 2944 {Angstrom} is generated by conventional laser techniques. The seed pulse produces an intense energy modulation of the rear part of a I GeV, 1245 {Angstrom} electron beam in a `modulator` wiggler. In the `radiator` wiggler, (resonant to 64 {Angstrom}), the energy modulation creates beam density modulation followed by radiation of the 46{sup th} harmonic of the seed. We use a magnetic delay to position the 64 A{Angstrom} radiation at the undisturbed front of the bunch to serve as a seed for a single pass, exponential growth FEL. After a 9 m long exponential section followed by a 7 m long tapered section the radiation power reaches 3.3 GW.

  16. Characteristics of a high-intensity plasma flash x-ray generator having a double-target radiation tube

    NASA Astrophysics Data System (ADS)

    Sato, Eiichi; Sagae, Michiaki; Takahashi, Kei; Oizumi, Teiji; Hayasi, Yasuomi; Tamakawa, Yoshiharu; Yanagisawa, Toru

    1995-05-01

    The radiographic characteristics of a high-intensity plasma flash x-ray generator having a solid-target (anode) radiation tube are described. This generator consisted of the following essential components; a high- voltage power supply, a low-impedance coaxial transmission line, a coaxial oil condenser of 0.2 (mu) F, a turbo-molecular pump, a thyratron pulser as a trigger device, and a flash x-ray triode having a rod-shaped long double anode; a 2.0 mm inner tungsten anode was embedded in 3.0 mm copper anode. The high-voltage condenser was charged from 40 to 60 kV by the power supply, and the electric charges in the condenser were discharged to the tube after triggering the cathode electrode. The maximum tube voltage was equivalent to the charged voltage of the main condenser, and the voltage decreased after the triggering. Both the tube voltage and the current displayed damped oscillations, and the maximum tube current was less than 20 kA. The pulse height of the flash x rays substantially increased according to increases in the charged voltage, and the x-ray durations had values of a few microseconds. The plasma x- ray source substantially grew when the charged voltage was increased. The flash x-ray spectra from the plasma x-ray source were measured by a transmission-type spectrometer having a LiF curved crystal of 0.5 mm in thickness. Compared to the intensities of copper K(alpha) 1 and K(alpha) 2 including nondiagram lines increased by using the double target.

  17. Three-dimensional time and frequency-domain theory of femtosecond x-ray pulse generation through Thomson Scattering

    SciTech Connect

    Brown, W J; Hartemann, F V

    2004-01-27

    The generation of high intensity, ultra-short x-ray pulses enables exciting new experimental capabilities, such as femtosecond pump-probe experiments used to temporally resolve material structural dynamics on atomic time scales. Thomson backscattering of a high intensity laser pulse with a bright relativistic electron bunch is a promising method for producing such high brightness x-ray pulses in the 10-100 keV range within a compact facility. While a variety of methods for producing sub-picosecond x-ray bursts by Thomson scattering exist, including compression of the electron bunch to sub-picosecond bunch lengths and/or colliding a sub-picosecond laser pulse in a side-on geometry to minimize the interaction time, a promising alternative approach to achieving this goal while maintaining ultra-high brightness is the production of a time correlated (or chirped) x-ray pulse in conjunction with pulse slicing or compression. We present the results of a complete analysis of this process using a recently developed 3-D time and frequency-domain code for analyzing the spatial, temporal, and spectral properties an x-ray beam produced by relativistic Thomson scattering. Based on the relativistic differential cross section, this code has the capability to calculate time and space dependent spectra of the x-ray photons produced from linear Thomson scattering for both bandwidth-limited and chirped incident laser pulses. Spectral broadening of the scattered x-ray pulse resulting from the incident laser bandwidth, laser focus, and the transverse and longitudinal phase space of the electron beam were examined. Simulations of chirped x-ray pulse production using both a chirped electron beam and a chirped laser pulse are presented. Required electron beam and laser parameters are summarized by investigating the effects of beam emittance, energy spread, and laser bandwidth on the scattered x-ray spectrum. It is shown that sufficient temporal correlation in the scattered x-ray spectrum

  18. Fundamental studies for the high-intensity long-duration flash x-ray generator for biomedical radiography

    NASA Astrophysics Data System (ADS)

    Sato, Eiichi; Isobe, Hiroshi; Takahashi, Kei; Tamakawa, Yoshiharu; Yanagisawa, Toru

    1991-04-01

    The fundamental studies for the repetitive high-intensity microsecond x-ray generator utilizing a cold cathode tetrode are described. This generator consisted of the following essential components: a constant high-voltage power supply, an energy storage condenser of 500nF, an main discharge condenser of lOnF, a turbo molecular pump, a repetitive trigger device, and an x-ray tube. The condenser was charged from 40 to 80kV, and the electric charges in the condenser were discharged repetitively to an x-ray tube by a trigger device. The x-ray tube was of the tetrode type which was connected to a turbo molecular pump and consisted of the following major parts: a rod-shaped long anode tip made of tungsten, a cathode rod made of graphite, a ring-shaped grid electrode, and a trigger electrode. The trigger electrode was mounted at the center of the cathode electrode and was insulated by a ceramic tube. The tube current was about 0. 4kA with a charged voltage of 60kV. The x-ray pulse height and the time-integrated intensity increased when the condenser charged voltage was increased, and the intensity was less than 2. OpC/kg at lm per pulse. The exposure times were about 2Ops, and the repetition frequency was less than 50Hz.

  19. A Pulsed X-Ray And Charged Particle Beam Generator Used In The Low Photon Energy Region

    NASA Astrophysics Data System (ADS)

    Sato, Eiichi; Isobe, Hiroshi; Tamakawa, Yoshiharu; Yanagisawa, Toru

    1989-06-01

    The construction and the fundamental studies for a pulsed x-ray and charged particle beam generator used in the low photon energy region are described. This generator consisted of the following components: a high-voltage power supply, a high-voltage coaxial oil condenser of 120kV-0.2pF, a gas gap switch, a low-impedance coaxial transmission line, a turbo molecular pump, and a pulsed x-ray and charged particle beam tube. The condenser was charged from -60 to -100kV and was connected to the radiation tube through a gas gap switch. The electric charge stored by the condenser was discharged to the radiation tube when the gas gap switch was closed. This radiation tube produced pulsed (flash) x-rays through copper foil anodes. The charged particle beam was produced by the ionized air outside of the anode window due to the production of a high dose rate of x-rays, and these charged particles were accelerated by the electric field between the anode and ground. Both kinds of radiation were produced simultaneously, and the migration time of the charged particles corresponded to the duration of the pulsed x-rays.

  20. Generating femtosecond X-ray pulses using an emittance-spoiling foil in free-electron lasers

    NASA Astrophysics Data System (ADS)

    Ding, Y.; Behrens, C.; Coffee, R.; Decker, F.-J.; Emma, P.; Field, C.; Helml, W.; Huang, Z.; Krejcik, P.; Krzywinski, J.; Loos, H.; Lutman, A.; Marinelli, A.; Maxwell, T. J.; Turner, J.

    2015-11-01

    Generation of femtosecond to sub-femtosecond pulses is attracting much attention in X-ray free-electron laser user community. One method is to use a slotted, emittance-spoiling foil which was proposed before (P. Emma et al., Phys. Rev. Lett. 92, 074801 (2004)) and has been widely used at the Linac Coherent Light Source. Direct experimental characterization of the slotted-foil performance was previously unfeasible due to a lack of appropriate diagnostics. With a recently installed X-band radio-frequency transverse deflector, we are able to characterize the electron bunch spoiling effect and X-ray pulse when using the slotted foil. We show that few-femtosecond X-ray pulses are generated with flexible control of the single-pulse duration or double-pulse separation with comparison to the theoretical model.

  1. Generating femtosecond X-ray pulses using an emittance-spoiling foil in free-electron lasers

    SciTech Connect

    Ding, Y. Coffee, R.; Decker, F.-J.; Emma, P.; Field, C.; Huang, Z.; Krejcik, P.; Krzywinski, J.; Loos, H.; Lutman, A.; Marinelli, A.; Maxwell, T. J.; Turner, J.; Behrens, C.; Helml, W.

    2015-11-09

    Generation of femtosecond to sub-femtosecond pulses is attracting much attention in X-ray free-electron laser user community. One method is to use a slotted, emittance-spoiling foil which was proposed before (P. Emma et al., Phys. Rev. Lett. 92, 074801 (2004)) and has been widely used at the Linac Coherent Light Source. Direct experimental characterization of the slotted-foil performance was previously unfeasible due to a lack of appropriate diagnostics. With a recently installed X-band radio-frequency transverse deflector, we are able to characterize the electron bunch spoiling effect and X-ray pulse when using the slotted foil. We show that few-femtosecond X-ray pulses are generated with flexible control of the single-pulse duration or double-pulse separation with comparison to the theoretical model.

  2. Harmonic Generation at Lower Electron Energies for a Hard X-ray FEL

    SciTech Connect

    Marksteiner, Quinn R.

    2011-01-01

    There are several schemes currently being investigated to pre-bunch the electron beam and step the coherent bunching up to higher harmonics, all which require modulator sections which introduce additional energy modulation. X-ray FELs operate in a regime where the FEL parameter, {rho} is equal to or less than the effective energy spread introduced from the emittance in the electron beam. Because of this large effective energy spread, the energy modulation introduced from harmonic generation schemes would seriously degrade FEL performance. This problem can be mitigated by incorporating the harmonic generation scheme at a lower electron kinetic energy than the energy at the final undulator. This will help because the effective energy spread from emittance is reduced at lower energies, and can be further reduced by making the beam transversely large. Then the beam can be squeezed down slowly enough in the subsequent accelerator sections so that geometric debunching is mitigated. The beam size inside the dispersive chicanes and in the accelerator sections must be carefully optimized to avoid debunching, and each subharmonic modulator section must generate enough energy modulation to overcome the SASE noise without significantly increasing the gain length in the final undulator. Here we show analytical results that demonstrate the feasibility of this harmonic pre-bunching scheme.

  3. A Serial-Exposure Type of High Intensity Flash X-ray Generator Having Variable Energies

    NASA Astrophysics Data System (ADS)

    Sato, Eiichi; Isobe, Hiroshi; Yanagisawa, Toru; Hoshino, Fumihiko

    1986-12-01

    The construction of a serial (triple) exposure type of high intensity flash x-ray (FX) generator having variable energies for biomedical radiography is described. This generator consisted of the following components: two high voltage generators (positive and negative), a voltage divider unit, two types of high and low voltage pulsers with maximum output voltages ranging from 50 to 200kV, small-sized trigger devices, a trigger delay unit, a high power gas diode, one turbo molecular pump, and two evacuated remote FX tubes, each of a different type. In the case of using a single FX tube, the pulser were charged to the same or different energies from -100kV to +100kV by using a two voltage divider unit and were connected to the FX tube through a high power gas diode. On the other hand, when using multiple tubes, the pulsers were connected directly to the tubes without a diode. These FX's have many possible diagnostic applications as follows: (1) high intensity stroboscopic radiography; (2) double exposure subtraction and energy subtraction; (3) superposition of spectra; (4) radiation sources for the ultra high speed computed tomography and stereography; and (5) various kinds of imaging using pulsed electron beams and FX.

  4. Second and third harmonic generation at UV and soft x-ray wavelengths from semiconductor gratings

    NASA Astrophysics Data System (ADS)

    Vincenti, M. A.; de Ceglia, D.; Scalora, M.

    2011-10-01

    Extraordinary transmission properties are demonstrated in the UV range for GaAs gratings with sub-wavelength apertures under TM-polarization excitation. The metal-like response below 270nm, typical of several semiconductors such as GaAs or GaP, in fact may be used to excite surface waves that lead to enhance transmission in the linear regime and for novel nonlinear optical phenomena in the UV and soft X-ray ranges. An investigation of the linear transmission as a function of geometrical parameters of the grating reveals the formation of surface waves and relatively high transmission values even in regimes where the nominal absorption is significant. Strong field localization in subwavelength cavities and on the surface of the grating can be achieved under proper excitation conditions leading to the enhancement of harmonic generation. Nonlinear contributions to harmonic generation arise from symmetry breaking, the nonlinear magnetic Lorentz force, and from intrinsic, dipolar volume contributions. Preliminary results show promising nonlinear conversion efficiencies at wavelengths below 100nm, and demonstrate cross-coupling of TE and TM polarizations for pump and harmonic signals. A down-conversion process that can re-generate pump photons of polarization orthogonal compared to the incident pump field is also demonstrated.

  5. IQ Aur: A new mode of X-ray generation in magnetic stars ?

    NASA Astrophysics Data System (ADS)

    Schmitt, Jurgen

    2007-10-01

    We propose to obtain the first high-resolution X-ray spectrum of the peculiar magnetic A-type star IQ Aur. From previous X-ray observations IQ Aur is known as a strong (LX ~ 4 10**29 erg/s), but very soft (TX ~ 0.29 keV) X-ray source. An attribution of IQ~Aur's X-ray emission to a low-mass companion would imply totally unusual properties of such an hypothesized object, thus IQ Aur is a good candidate for an A-type star with intrinsic X-ray emission.The XMM-Newton RGS spectrum will constrain the location of the X-ray emission site from a measurement or upper limit to the strength of the OVII f line, the overall RGS spectrum will determine the elemental abundances, which may be far away from solar,and the phase coverage will allow a search for rotational modulation of IQ Aur's X-ray flux.

  6. Laser wakefield generated X-ray probe for femtosecond time-resolved measurements of ionization states of warm dense aluminum

    NASA Astrophysics Data System (ADS)

    Mo, M. Z.; Chen, Z.; Fourmaux, S.; Saraf, A.; Otani, K.; Kieffer, J. C.; Tsui, Y. Y.; Ng, A.; Fedosejevs, R.

    2013-12-01

    We have developed a laser wakefield generated X-ray probe to directly measure the temporal evolution of the ionization states in warm dense aluminum by means of absorption spectroscopy. As a promising alternative to the free electron excited X-ray sources, Betatron X-ray radiation, with femtosecond pulse duration, provides a new technique to diagnose femtosecond to picosecond transitions in the atomic structure. The X-ray probe system consists of an adjustable Kirkpatrick-Baez (KB) microscope for focusing the Betatron emission to a small probe spot on the sample being measured, and a flat Potassium Acid Phthalate Bragg crystal spectrometer to measure the transmitted X-ray spectrum in the region of the aluminum K-edge absorption lines. An X-ray focal spot size of around 50 μm was achieved after reflection from the platinum-coated 10-cm-long KB microscope mirrors. Shot to shot positioning stability of the Betatron radiation was measured resulting in an rms shot to shot variation in spatial pointing on the sample of 16 μm. The entire probe setup had a spectral resolution of ˜1.5 eV, a detection bandwidth of ˜24 eV, and an overall photon throughput efficiency of the order of 10-5. Approximately 10 photons were detected by the X-ray CCD per laser shot within the spectrally resolved detection band. Thus, it is expected that hundreds of shots will be required per absorption spectrum to clearly observe the K-shell absorption features expected from the ionization states of the warm dense aluminum.

  7. Status of the LBL experiment on femtosecond x-ray generation through 90{degree} Thomson scattering

    SciTech Connect

    Leemans, W.; Chattopadhyay, S.; Conde, M.; Glover, E.; Kim, K.J.; Schoenlein, R.; Shank, C.V.

    1994-06-01

    A status report on the generation of femtosecond X-ray pulses through 90{degrees} Thompson scattering is presented. The experiment involves a relativistic electron beam (tunable from 25--50 MeV) with a bunch length of 10 ps containing 1 {minus}2 nC, and a ultrashort pulse (50--200 fs), high power (4 TW) 0.8 {mu}m Ti:Al{sub 2}O{sub 3} laser system. Both beams are focussed down to about a 50 {mu}m waist size and intersect at 90{degrees}. The laser field acts as an electromagnetic undulator for the relativistic electron beam generating radiation upshifted by 2 {gamma}{sup 2} and a pulse length given by the transit time of the laser beam across the electron beam. For a 50 MeV electron beam we expect 10{sup 5} photons at 0.4 {angstrom} (10% bandwidth) in a cone angle of 6 mrad in a 170 fs pulse.

  8. Generation of ultrahigh-energy gamma rays in accreting x ray pulsars

    NASA Technical Reports Server (NTRS)

    Gnedin, Yu. N.; Ikhsanov, N. R.

    1991-01-01

    Relativistic protons producing ultrahigh energy gamma rays as a result of nuclear collisions ought to be generated in close proximity to the surface of a neutron star due to accretion. The main features of the mechanism in question are a high efficiency of conversion of the gravitational energy of the accreting matter into acceleration energy and a high efficiency of the acceleration itself. It is shown that in accretion to a neutron star with a strong magnetic field, a loss cone type distribution of accreting protons is formed, which due to instability effectively generates small scale Alfven and proton cyclotron waves, as well as nonlinear waves (magneto-acoustic and Alfven solitons). The electric field of the moving solitons may accelerate the protons to energies of greater than 10(exp 15) eV. The region of acceleration is not locally isolated, but extends from its surface. New possible sources of ultrahigh energy gamma rays are predicted. They may be binary x ray systems containing neutron stars with magnetic fields of about 10(exp 9) gauss.

  9. Principal component analysis of soft x-ray signals generated by the PF-1000 facility in experiments with solid targets

    NASA Astrophysics Data System (ADS)

    Kowalska-Strzęciwilk, Ewa; Skrzeczanowski, Wojciech; Czarnecka, Agata; Kubkowska, Monika; Paduch, Marian; Zielińska, Ewa

    2014-05-01

    The paper presents the analysis of soft x-ray signals generated in the PF-1000 facility equipped with a modified inner electrode with a central tungsten insert of 50 mm diameter in experiments with tungsten and carbon samples. The PF-1000 machine was operated with pure deuterium filling under the initial pressure of 1.3 hPa. The machine was powered using a condenser bank charged initially to 24 kV, corresponding to the stored energy of 380 kJ, with the maximum discharge current amounted to 1.8 MA. For investigation of plasma stream-sample interactions, we applied 16-frame laser interferometry, optical spectroscopy and soft x-ray measurements with the use of a system of four silicon pin-diodes. In this paper, we mainly focus on the principal component analysis (PCA) of the registered x-ray signals to find a corelation between the neutron yield and observed maxima in signals. X-ray signals collected by four pin-diodes covered a 9 cm range in front of the electrode ends. Each diode collected a signal from the circle of 3 cm diameter. The presented PCA analysis is based on 57 PF discharges and 16 parameters are taken into account in the analysis. The study of signals from the pin-diode system showed good correlation between the neutron yield and the maximum in the x-ray signal, which appeared about 1000-1300 ns after the maximum of plasma compression.

  10. A model for the distribution of material generating the soft X-ray background

    SciTech Connect

    Snowden, S.L.; Cox, D.P.; Mccammon, D.; Sanders, W.T. )

    1990-05-01

    The observational evidence relating to the soft X-ray diffuse background is discussed, and a simple model for its source and spatial structure is presented. In this simple model with one free parameter, the observed 1/4 keV X-ray intensity originates as thermal emission from a uniform hot plasma filling a cavity in the neutral material of the Galactic disk which contains the sun. Variations in the observed X-ray intensity are due to variations in the extent of the emission volume and therefore the emission measure of the plasma. The model reproduces the observed negative correlation between X-ray intensity and H I column density and predicts reasonable values for interstellar medium parameters. 64 refs.

  11. A model for the distribution of material generating the soft X-ray background

    NASA Technical Reports Server (NTRS)

    Snowden, S. L.; Cox, D. P.; Mccammon, D.; Sanders, W. T.

    1990-01-01

    The observational evidence relating to the soft X-ray diffuse background is discussed, and a simple model for its source and spatial structure is presented. In this simple model with one free parameter, the observed 1/4 keV X-ray intensity originates as thermal emission from a uniform hot plasma filling a cavity in the neutral material of the Galactic disk which contains the sun. Variations in the observed X-ray intensity are due to variations in the extent of the emission volume and therefore the emission measure of the plasma. The model reproduces the observed negative correlation between X-ray intensity and H I column density and predicts reasonable values for interstellar medium parameters.

  12. Next Generation X-Ray Optics: High-Resolution, Light-Weight, and Low-Cost

    NASA Technical Reports Server (NTRS)

    Zhang, William W.

    2012-01-01

    X-ray telescopes are essential to the future of x-ray astronomy. In this talk I will describe a comprehensive program to advance the technology for x-ray telescopes well beyond the state of the art represented by the three currently operating missions: Chandra, XMM-Newton, and Suzaku. This program will address the three key issues in making an x-ray telescope: (1) angular resolution, (2) effective area per unit mass, and (3) cost per unit effective area. The objectives of this technology program are (1) in the near term, to enable Explorer-class x-ray missions and an IXO-type mission, and (2) in the long term, to enable a flagship x-ray mission with sub-arcsecond angular resolution and multi-square-meter effective area, at an affordable cost. We pursue two approaches concurrently, emphasizing the first approach in the near term (2-5 years) and the second in the long term (4-10 years). The first approach is precision slumping of borosilicate glass sheets. By design and choice at the outset, this technique makes lightweight and low-cost mirrors. The development program will continue to improve angular resolution, to enable the production of 5-arcsecond x-ray telescopes, to support Explorer-class missions and one or more missions to supersede the original IXO mission. The second approach is precision polishing and light-weighting of single-crystal silicon mirrors. This approach benefits from two recent commercial developments: (1) the inexpensive and abundant availability of large blocks of monocrystalline silicon, and (2) revolutionary advances in deterministic, precision polishing of mirrors. By design and choice at the outset, this technique is capable of producing lightweight mirrors with sub-arcsecond angular resolution. The development program will increase the efficiency and reduce the cost of the polishing and the light-weighting processes, to enable the production of lightweight sub-arcsecond x-ray telescopes. Concurrent with the fabrication of lightweight

  13. Next Generation X-Ray Optics: High-Resolution, Light-Weight, and Low-Cost

    NASA Technical Reports Server (NTRS)

    Zhang, William W.

    2011-01-01

    X-ray telescopes are essential to the future of x-ray astronomy. This paper describes a comprehensive program to advance the technology for x-ray telescopes well beyond the state of the art represented by the three currently operating missions: Chandra, XMM-Newton , and Suzaku . This program will address the three key issues in making an x-ray telescope: (I) angular resolution, (2) effective area per unit mass, and (3) cost per unit effective area. The objectives of this technology program are (1) in the near term, to enable Explorer-class x-ray missions and an IXO type mission, and (2) in the long term, to enable a flagship x-ray mission with sub-arcsecond angular resolution and multi-square-meter effective area, at an affordable cost. We pursue two approaches concurrently, emphasizing the first approach in the near term (2-5 years) and the second in the long term (4-10 years). The first approach is precision slumping of borosilicate glass sheets. By design and choice at the outset, this technique makes lightweight and low-cost mirrors. The development program will continue to improve angular resolution, to enable the production of 5-arcsecond x-ray telescopes, to support Explorer-class missions and one or more missions to supersede the original IXO mission. The second approach is precision polishing and light-weighting of single-crystal silicon mirrors. This approach benefits from two recent commercial developments: (1) the inexpensive and abundant availability of large blocks of mono crystalline silicon, and (2) revolutionary advances in deterministic, precision polishing of mirrors. By design and choice at the outset, this technique is capable of producing lightweight mirrors with sub-arcsecond angular resolution. The development program will increase the efficiency and reduce the cost of the polishing and the lightweighting processes, to enable the production of lightweight sub-arcsecond x-ray telescopes. Concurrent with the fabrication of lightweight mirror

  14. [Antidepressives of the 3rd, 4th and 5th generation].

    PubMed

    Svestka, J

    1994-02-01

    Antidepressants are classified into five generations. Preparations of the first generation affect various neurotransmitter systems and are therefore associated with many undesirable effects (e.g. tricyclic antidepressants, maprotiline). The second generation of antidepressants is already devoid of anticholinergic action and their adrenolytic and antihistaminic effects are weaker (e.g. mianserine, mirtazapine, trazodone). The antidepressant action of preparations of the third generation is mediated only by one of the three main neurotransmitter systems for depression (5-HT, noradrenaline, dopamine) and does not affect muscarine, histamine and adrenergic cerebral systems (e.g. SSRI, ipsapirone, viloxazine, reboxetine, bupropione). Recently antidepressants of the fourth generation were synthetized which influence only the serotonin, and noradrenaline or dopamine system (e.g. milnacipran, befloxatone). The fifth generation of antidepressants foresees the exclusive action on 5-HT, noradrenaline and dopamine systems of the CNS in varying ratios (e.g. venlafaxine, cericlamine). PMID:8174184

  15. Generation of hard x rays by femtosecond laser pulse interaction with Cu in laminar helium flow in ambient air

    SciTech Connect

    Hou Bixue; Easter, James; Krushelnick, Karl; Nees, John A.

    2008-04-21

    Hard x rays are generated in laminar helium flow in atmosphere (without a vacuum vessel) through the interaction of tightly focused 35 fs laser pulses of varying energy with a Cu target. The energy conversion efficiency from laser to K{alpha} x rays is measured to be 5.4x10{sup -6}, giving a flux of 5.9x10{sup 9} photons/s into 2{pi} sr from a source measuring approximately 9x12 {mu}m{sup 2} in size (verticalxhorizontal). Results are compared to those measured in vacuum and in static helium environments.

  16. Ionization injection effects in x-ray spectra generated by betatron oscillations in a laser wakefield accelerator

    NASA Astrophysics Data System (ADS)

    Behm, K. T.; Zhao, T. Z.; Cole, J. M.; Maksimchuk, A.; Mangles, S. P. D.; Nees, J.; Wood, J. C.; Yanovsky, V.; Krushelnick, K.; Thomas, A. G. R.

    2016-05-01

    Single photon counting techniques were used with an x-ray CCD camera to measure features of synchrotron-like x-ray spectra generated by betatron oscillations of electrons in a laser wakefield accelerator (LWFA) with different injection techniques. Measurements were made using the Hercules laser system at the University of Michigan. With a single stage gas cell, we demonstrate that pure helium gas in our wakefield accelerator will produce spectra with higher critical energies than when helium mixed with nitrogen is used. This result was not evident when a two stage gas cell was used.

  17. Investigating radial wire array Z pinches as a compact x-ray source on the Saturn generator

    DOE PAGESBeta

    Ampleford, David J.; Bland, S. N.; Jennings, Christopher A.; Lebedev, S. V.; Chittenden, J. P.; Cuneo, Michael E.; McBride, Ryan D.; Jones, Brent Manley; Hall, G. N.; Suzuki-Vidal, F.; et al

    2015-08-27

    Radial wire array z pinches, where wires are positioned radially outward from a central cathode to a concentric anode, can act as a compact bright x-ray source that could potentially be used to drive a hohlraum. Experiments were performed on the 7-MA Saturn generator using radial wire arrays. These experiments studied a number of potential risks in scaling radial wire arrays up from the 1-MA level, where they have been shown to be a promising compact X-ray source. Data indicates that at 7 MA, radial wire arrays can radiate ~9 TW with 10-ns full-width at half-maximum from a compact pinch.

  18. Generation of focused electron beam and X-rays by the doped LiNbO 3 crystals

    NASA Astrophysics Data System (ADS)

    Bayssie, M.; Brownridge, J. D.; Kukhtarev, N.; Kukhtarev, T.; Wang, J. C.

    2005-12-01

    Generation of focused electrons beam with energies up to 100 keV from undoped LiNbO3 (LN) crystals have been observed [J.D. Brownridge, Nature 358 (1992) 287; J.D. Brownridge, S.M. Shafroth, Appl. Phys. Lett. 79 (2001) 3364] during heating-cooling cycles in a low-pressure environment. This paper reports about similar results that were observed in doped crystals of LN. Generation of electrons by crystals with thicknesses of 1 and 6 mm, was visualized by ZnS screen [ZSS] during heating-cooling cycles in a vacuum chamber (P = 1-10 mTorr). Generation of X-rays from both thin and thick crystals was evident from registered images from dental X-ray film [DXF]. The possibility of X-ray imaging was demonstrated, using different metal masks. Imaging of X-rays reveals that both focusing and wide-angle scattering modes of operation exist in the electron beams generation pattern during heating-cooling cycles.

  19. Femtosecond X-ray generation through 90{sup o} Thomson scattering: Status of the LBL experiment

    SciTech Connect

    Leemans, W.; Schoenlein, R.; Chin, A.; Glover, E.; Conde, M.; Chattopadhyay, S.; Kim, K.J.; Shank, C.V.

    1994-11-01

    Scattering of femotosecond laser pulses off a low energy relativistic electron beam at 90{sup o} offers the possibility to generate ultrashort X-ray pulses. Experiments are under preparation in the Beam Test Facility of the Center for Beam Physics at LBL to demonstrate the generation and detection of such pulses. The experiments involve a relativistic electron beam (tunable from 25-50 MeV) with a bunch length of 10 ps containing 1-2 nC, and an ultra short pulse (50-200 fs), high peak power (>2 TW) 0.8 {mu}m Ti:Al{sub 2}O{sub 3} laser system. The electron beam, focused down to about a 50 {mu}m waist size intersects the focused laser beam at 90{sup o}. The laser field acts as an electromagnetic undulator with strength K (quiver velocity of an electron normalized to the speed of light) for the relativistic electron beam, generating radiation up-shifted by 2{gamma}{sup 2}/(1+K{sup 2}/2) and a pulse length given by the overlapped interaction length in time of the laser beam and the electron beam. Here {gamma} is the usual Lorentz factor. Wavelength tuning will be accomplished in the experiment by generating wiggler strengths on the order of one as well as by electron beam energy tuning. For a 50 MeV electron beam and a laser beam focused to an intensity on the order of 10{sup 16} W/cm{sup 2}, the authors expect 10{sup 5} photons at 0.4 {angstrom} (10% bandwidth) in a cone angle of 6 mrad in a 170 fs pulse.

  20. SHIELDING ANALYSIS FOR X-RAY SOURCES GENERATED IN TARGET CHAMBER OF THE NATIONAL IGNITION FACILITY

    SciTech Connect

    Khater, H Y; Brereton, S J; Singh, M S

    2008-03-27

    Prompt doses from x-rays generated as result of laser beam interaction with target material are calculated at different locations inside the National Ignition Facility (NIF). The maximum dose outside a Target Chamber diagnostic port is {approx} 1 rem for a shot utilizing the 192 laser beams and 1.8 MJ of laser energy. The dose during a single bundle shot (8 laser beams) drops to {approx} 40 mrem. Doses calculated outside the Target Bay doors and inside the Switchyards (except for the 17 ft.-6 in. level) range from a fraction of mrem to about 11 mrem for 192 beams, and scales down proportionally with smaller number of beams. At the 17ft.-6 in. level, two diagnostic ports are directly facing two of the Target Bay doors and the maximum doses outside the doors are 51 and 15.5 mrem, respectively. Shielding each of the two Target Bay doors with 1/4 in. Pb reduces the dose by factor of fifty. One or two bundle shots (8 to 16 laser beams) present a small hazard to personnel in the Switchyards.

  1. ATHENA: system design and implementation for a next generation x-ray telescope

    NASA Astrophysics Data System (ADS)

    Ayre, M.; Bavdaz, M.; Ferreira, I.; Wille, E.; Lumb, D.; Linder, M.

    2015-08-01

    ATHENA, Europe's next generation x-ray telescope, has recently been selected for the 'L2' slot in ESA's Cosmic Vision Programme, with a mandate to address the 'Hot and Energetic Universe' Cosmic Vision science theme. The mission is currently in the Assessment/Definition Phase (A/B1), with a view to formal adoption after a successful System Requirements Review in 2019. This paper will describe the reference mission architecture and spacecraft design produced during Phase 0 by the ESA Concurrent Design Facility (CDF), in response to the technical requirements and programmatic boundary conditions. The main technical requirements and their mapping to resulting design choices will be presented, at both mission and spacecraft level. An overview of the spacecraft design down to subsystem level will then be presented (including the telescope and instruments), remarking on the critically-enabling technologies where appropriate. Finally, a programmatic overview will be given of the on-going Assessment Phase, and a snapshot of the prospects for securing the `as-proposed' mission within the cost envelope will be given.

  2. Generating soft x-ray spectra using the SPEED pentaxial diode

    SciTech Connect

    McClenahan, C.R.; Hedemann, M.A.; Beezhold, W.; Counts, N.E.; Lynch, T.P.; Erven, D.J.; Reilly, J.P.

    1987-07-01

    At 70 kV charge voltage and three anode-cathode (A-K) gaps, 2.0, 2.5, and 3.0 mm, SPEED and the pentaxial diode provide bremsstrahlung-x-ray exposures with peak electron voltages of 350 +- 60, 490 +- 50, and 590 +- 50 kV. At these voltages, the pentax delivers peak dose rates of 0.16 +- 0.06, 0.33 +- 0.08, and 0.57 +- 0.10 . 10/sup 12/ rad(CaF/sub 2/)/s, respectively. The 4.4 cm radius opening in a steel clamp ring defines the high-exposure area of 60 cm/sup 2/, 2.1 cm from the tantalum converter. The peak dose occurs at a radius of 1.9 cm, with the axial dose reaching about 80% of the peak. The dose falls to about 70% of peak at 3.8 cm radius. We used the normal pentaxial diode hardware and charged the SPEED Marx generator to 70 kV instead of the normal 90 or 95 kV. A 30 cm diameter and 30 cm deep re-entrant bellows on the vacuum chamber contains the exposure area and maintains a normal atmosphere around the test object. Thermoluminescent dosimeters (TLDs) measured the dose to CaF/sub 2/, and silicon PIN diodes measured the radiation pulse width.

  3. Generating soft X-ray spectra using the SPEED pentaxial diode

    NASA Astrophysics Data System (ADS)

    McClenahan, C. R.; Hedemann, M. A.; Beezhold, W.; Counts, N. E.; Lynch, T. P.; Erven, D. J.; Reilly, J. P.

    1987-07-01

    At 70 kV charge voltage and three anode-cathode (A-K) gaps, 2.0, 2.5, and 3.0 mm, SPEED and the pentaxial diode provide bremsstrahlung-x-ray exposures with peak electron voltages of 350 +/- 60, 490 +/- 50, and 590 +/- 50 kV. At these voltages, the pentax delivers peak dose rates of 0.16 +/- 0.06, 0.33 +/- 0.08, and 0.57 +/- 0.10 x 10 to the 12th rad(CaF2)/s, respectively. The 4.4 cm radius opening in a steel clamp ring defines the high-exposure area of 60 sq cm, 2.1 cm from the tantalum converter. The peak dose occurs at a radius of 1.9 cm, with the axial dose reaching about 80% of the peak. The dose falls to about 70% of peak at 3.8 cm radius. We used the normal pentaxial diode hardware and charged the SPEED Marx generator to 70 kV instead of the normal 90 or 95 kV. A 30 cm diameter and 30 cm deep re-entrant bellows on the vacuum chamber contains the exposure area and maintains a normal atmosphere around the test object. Thermoluminescent dosimeters (TLDs) measured the dose to CaF2, and silicon PIN diodes measured the radiation pulse width.

  4. Generation of bright attosecond x-ray pulse trains via Thomson scattering from laser-plasma accelerators.

    PubMed

    Luo, W; Yu, T P; Chen, M; Song, Y M; Zhu, Z C; Ma, Y Y; Zhuo, H B

    2014-12-29

    Generation of attosecond x-ray pulse attracts more and more attention within the advanced light source user community due to its potentially wide applications. Here we propose an all-optical scheme to generate bright, attosecond hard x-ray pulse trains by Thomson backscattering of similarly structured electron beams produced in a vacuum channel by a tightly focused laser pulse. Design parameters for a proof-of-concept experiment are presented and demonstrated by using a particle-in-cell code and a four-dimensional laser-Compton scattering simulation code to model both the laser-based electron acceleration and Thomson scattering processes. Trains of 200 attosecond duration hard x-ray pulses holding stable longitudinal spacing with photon energies approaching 50 keV and maximum achievable peak brightness up to 1020 photons/s/mm2/mrad2/0.1%BW for each micro-bunch are observed. The suggested physical scheme for attosecond x-ray pulse trains generation may directly access the fastest time scales relevant to electron dynamics in atoms, molecules and materials. PMID:25607175

  5. Design of Hanford Site 4th Generation Multi Function Corrosion Monitoring System

    SciTech Connect

    NORMAN, E.C.

    2000-08-30

    This document describes the design of the fourth-generation corrosion monitoring system scheduled to be installed in DST 241-AN-104 early in fiscal year 2001. A fourth-generation multi-function corrosion monitoring system has been designed for installation into a DST in the 241-AN farm at the Hanford Site in FY 2001. Improvements and upgrades from the third-generation system (installed in 241-AN-105) that have been incorporated into the fourth-generation system include: Addition of a built-in water lance to assist installation of probe into tanks with a hard crust layer at the surface of the waste; and Improvement of the electrode mounting apparatus used to attach the corrosion monitoring electrodes to the stainless steel probe body (new design simplifies probe assembly/wiring). These new features improve on the third-generation design and yield a system that is easier to fabricate and install, provides for a better understanding of the relationship between corrosion and other tank operating parameters, and optimizes the use of the riser that houses the probe in the tank.

  6. Testing quantum mechanics in non-Minkowski space-time with high power lasers and 4th generation light sources

    PubMed Central

    Crowley, B. J. B.; Bingham, R.; Evans, R. G.; Gericke, D. O.; Landen, O. L.; Murphy, C. D.; Norreys, P. A.; Rose, S. J.; Tschentscher, Th; Wang, C. H.-T; Wark, J. S.; Gregori, G.

    2012-01-01

    A common misperception of quantum gravity is that it requires accessing energies up to the Planck scale of 1019 GeV, which is unattainable from any conceivable particle collider. Thanks to the development of ultra-high intensity optical lasers, very large accelerations can be now the reached at their focal spot, thus mimicking, by virtue of the equivalence principle, a non Minkowski space-time. Here we derive a semiclassical extension of quantum mechanics that applies to different metrics, but under the assumption of weak gravity. We use our results to show that Thomson scattering of photons by uniformly accelerated electrons predicts an observable effect depending upon acceleration and local metric. In the laboratory frame, a broadening of the Thomson scattered x ray light from a fourth generation light source can be used to detect the modification of the metric associated to electrons accelerated in the field of a high power optical laser. PMID:22768381

  7. Assessment of different computational models for generation of x-ray spectra in diagnostic radiology and mammography.

    PubMed

    Ay, M R; Sarkar, S; Shahriari, M; Sardari, D; Zaidi, H

    2005-06-01

    Different computational methods based on empirical or semi-empirical models and sophisticated Monte Carlo calculations have been proposed for prediction of x-ray spectra both in diagnostic radiology and mammography. In this work, the x-ray spectra predicted by various computational models used in the diagnostic radiology and mammography energy range have been assessed by comparison with measured spectra and their effect on the calculation of absorbed dose and effective dose (ED) imparted to the adult ORNL hermaphroditic phantom quantified. This includes empirical models (TASMIP and MASMIP), semi-empirical models (X-rayb&m, X-raytbc, XCOMP, IPEM, Tucker et al., and Blough et al.), and Monte Carlo modeling (EGS4, ITS3.0, and MCNP4C). As part of the comparative assessment, the K x-ray yield, transmission curves, and half value layers (HVLs) have been calculated for the spectra generated with all computational models at different tube voltages. The measured x-ray spectra agreed well with the generated spectra when using X-raytbc and IPEM in diagnostic radiology and mammography energy ranges, respectively. Despite the systematic differences between the simulated and reference spectra for some models, the student's t-test statistical analysis showed there is no statistically significant difference between measured and generated spectra for all computational models investigated in this study. The MCNP4C-based Monte Carlo calculations showed there is no discernable discrepancy in the calculation of absorbed dose and ED in the adult ORNL hermaphroditic phantom when using different computational models for generating the x-ray spectra. Nevertheless, given the limited flexibility of the empirical and semi-empirical models, the spectra obtained through Monte Carlo modeling offer several advantages by providing detailed information about the interactions in the target and filters, which is relevant for the design of new target and filter combinations and optimization of

  8. Assessment of different computational models for generation of x-ray spectra in diagnostic radiology and mammography

    SciTech Connect

    Ay, M.R.; Sarkar, S.; Shahriari, M.; Sardari, D.; Zaidi, H.

    2005-06-15

    Different computational methods based on empirical or semi-empirical models and sophisticated Monte Carlo calculations have been proposed for prediction of x-ray spectra both in diagnostic radiology and mammography. In this work, the x-ray spectra predicted by various computational models used in the diagnostic radiology and mammography energy range have been assessed by comparison with measured spectra and their effect on the calculation of absorbed dose and effective dose (ED) imparted to the adult ORNL hermaphroditic phantom quantified. This includes empirical models (TASMIP and MASMIP), semi-empirical models (X-rayb and m, X-raytbc, XCOMP, IPEM, Tucker et al., and Blough et al.), and Monte Carlo modeling (EGS4, ITS3.0, and MCNP4C). As part of the comparative assessment, the K x-ray yield, transmission curves, and half value layers (HVLs) have been calculated for the spectra generated with all computational models at different tube voltages. The measured x-ray spectra agreed well with the generated spectra when using X-raytbc and IPEM in diagnostic radiology and mammography energy ranges, respectively. Despite the systematic differences between the simulated and reference spectra for some models, the student's t-test statistical analysis showed there is no statistically significant difference between measured and generated spectra for all computational models investigated in this study. The MCNP4C-based Monte Carlo calculations showed there is no discernable discrepancy in the calculation of absorbed dose and ED in the adult ORNL hermaphroditic phantom when using different computational models for generating the x-ray spectra. Nevertheless, given the limited flexibility of the empirical and semi-empirical models, the spectra obtained through Monte Carlo modeling offer several advantages by providing detailed information about the interactions in the target and filters, which is relevant for the design of new target and filter combinations and optimization of

  9. Geometrical Effect of Target Crystal on Pxr Generation as a Coherent X-Ray Source

    NASA Astrophysics Data System (ADS)

    Hayakawa, Y.; Hayakawa, K.; Inagaki, M.; Kuwada, T.; Nakao, K.; Nogami, K.; Sakai, T.; Sato, I.; Takahashi, Y.; Tanaka, T.

    2010-04-01

    The experiments of the PXR performance carried out for the target crystals with different cutting planes have shown significant difference in the PXR property, which suggests another way to increase the PXR intensity than by increasing the electron beam current. In order to investigate the effect of the geometrical condition of the crystal surface on the PXR property, the experiments have been carried out for the target crystal with a knife-edge-shaped cut surface. For the case with symmetric Bragg geometry on the front surface and asymmetric condition on the rear surface, the rather low intensity X-ray beam has shown considerably good spatial coherence. The X-ray beam with narrow line width has made it possible to obtain X-ray absorption spectra with a high resolution. In contrast, relatively high intensity, which enabled taking an absorption image with the exposure for several tens of seconds, has been obtained for the geometry with asymmetric front surface and symmetric rear surface. This configuration, however, has raised a problem of degradation in the spatial coherence of the X-rays due to the superposition of two different X-ray beams.

  10. Geometrical Effect of Target Crystal on Pxr Generation as a Coherent X-Ray Source

    NASA Astrophysics Data System (ADS)

    Hayakawa, Y.; Hayakawa, K.; Inagaki, M.; Kuwada, T.; Nakao, K.; Nogami, K.; Sakai, T.; Sato, I.; Takahashi, Y.; Tanaka, T.

    The experiments of the PXR performance carried out for the target crystals with different cutting planes have shown significant difference in the PXR property, which suggests another way to increase the PXR intensity than by increasing the electron beam current. In order to investigate the effect of the geometrical condition of the crystal surface on the PXR property, the experiments have been carried out for the target crystal with a knife-edge-shaped cut surface. For the case with symmetric Bragg geometry on the front surface and asymmetric condition on the rear surface, the rather low intensity X-ray beam has shown considerably good spatial coherence. The X-ray beam with narrow line width has made it possible to obtain X-ray absorption spectra with a high resolution. In contrast, relatively high intensity, which enabled taking an absorption image with the exposure for several tens of seconds, has been obtained for the geometry with asymmetric front surface and symmetric rear surface. This configuration, however, has raised a problem of degradation in the spatial coherence of the X-rays due to the superposition of two different X-ray beams.

  11. Rare decays of the Z and the standard model, 4th generation, and beyond

    SciTech Connect

    Weiler, T.J.

    1989-01-01

    Several issues in rare decays of the Z are addressed. The rate for flavor-changing Z decay grows as the fourth power of the fermion masses internal to the quantum loop, and so offers a window to the existence of ultraheavy (m > M{sub W}) fermions. In the standard model, with three generations, BR(Z {yields} bs) < 10{sup -7} and BR(Z{yields}tc)<10{sup -13}. With four generations, BR(Z {yields} bb{sub 4}) may be as large as 10{sup -5} if m{sub b4} < M{sub Z}; and similarly for BR(Z {yields} N{sub 4}v), where N{sub 4} is the possibly heavy fourth generation neutrino. In supersymmetric and other two Higgs doublet models, BR(Z {yields} tc) may be as large as 5 {times} 10{sup -6} in the three generation scheme. With minimal supersymmetry, the reaction Z {yields} H{gamma} is guaranteed to go, with a parameter-dependent branching ratio of 10{sup -6 {plus minus} 3}. With mirror fermions or exotic E{sub 6} fermions, the branching ratios for Z {yields} ct (70 GeV), Z {yields} {mu}{tau}, and Z {yields} bb{sub 4} (70 GeV) are typically 10{sup -4}, 10{sup -4}, and 10{sup -3} respectively, clearly measurable at LEP. Depending on unknown quark masses, the Z may mix with vector (b{sub 4}{bar b}{sub 4}) and the W may mix with vector (t{bar b}) or (t{bar s}). CP violating asymmetries in flavor-changing Z decay are immeasurably small in the standard model, but may be large in supersymmetric and other nonstandard models. 28 refs.

  12. Negative Delta-Rho in the "standard Model" from 4TH-GENERATION Bound States

    NASA Astrophysics Data System (ADS)

    McCoy, Richard Thomas, III

    The possible consequences of heavy fourth-generation "vector meson" bound states, formed by the exchange of the Higgs boson, are discussed within the context of the Standard Model with either one or two Higgs doublets. It is suggested that such bound states could make negative contributions to the rho parameter, thereby loosening the perturbative constraint upon the mass of the top quark (our model would permit rm m_{t} to be as large as 365 GeV in the one Higgs doublet scenario, for example) and/or the masses, mass splittings, and other characteristics of a potential fourth generation of heavy fermions. In the two Higgs doublet scenario, the contributions to the rho parameter coming solely from the scalar sector are also considered. It is found in that scenario that the way fermions couple to the Higgs doublets crucially determines whether or not one can have a heavy (>150 GeV) top quark, a light ( <80 GeV) charged scalar and/or rare "monojet" Z decays such as Z to Nnu _tau, where N is the fourth-generation neutral lepton.

  13. Compact hohlraum configuration with parallel planar-wire-array x-ray sources at the 1.7-MA Zebra generator.

    PubMed

    Kantsyrev, V L; Chuvatin, A S; Rudakov, L I; Velikovich, A L; Shrestha, I K; Esaulov, A A; Safronova, A S; Shlyaptseva, V V; Osborne, G C; Astanovitsky, A L; Weller, M E; Stafford, A; Schultz, K A; Cooper, M C; Cuneo, M E; Jones, B; Vesey, R A

    2014-12-01

    A compact Z-pinch x-ray hohlraum design with parallel-driven x-ray sources is experimentally demonstrated in a configuration with a central target and tailored shine shields at a 1.7-MA Zebra generator. Driving in parallel two magnetically decoupled compact double-planar-wire Z pinches has demonstrated the generation of synchronized x-ray bursts that correlated well in time with x-ray emission from a central reemission target. Good agreement between simulated and measured hohlraum radiation temperature of the central target is shown. The advantages of compact hohlraum design applications for multi-MA facilities are discussed. PMID:25615200

  14. Compact hohlraum configuration with parallel planar-wire-array x-ray sources at the 1.7-MA Zebra generator

    NASA Astrophysics Data System (ADS)

    Kantsyrev, V. L.; Chuvatin, A. S.; Rudakov, L. I.; Velikovich, A. L.; Shrestha, I. K.; Esaulov, A. A.; Safronova, A. S.; Shlyaptseva, V. V.; Osborne, G. C.; Astanovitsky, A. L.; Weller, M. E.; Stafford, A.; Schultz, K. A.; Cooper, M. C.; Cuneo, M. E.; Jones, B.; Vesey, R. A.

    2014-12-01

    A compact Z-pinch x-ray hohlraum design with parallel-driven x-ray sources is experimentally demonstrated in a configuration with a central target and tailored shine shields at a 1.7-MA Zebra generator. Driving in parallel two magnetically decoupled compact double-planar-wire Z pinches has demonstrated the generation of synchronized x-ray bursts that correlated well in time with x-ray emission from a central reemission target. Good agreement between simulated and measured hohlraum radiation temperature of the central target is shown. The advantages of compact hohlraum design applications for multi-MA facilities are discussed.

  15. Z-Pinch Generated X-Rays Demonstrate Indirect-Drive ICF Potential

    SciTech Connect

    Bowers, R.L.; Chandler, G.A.; Derzon, M.S.; Hebron, D.E.; Leeper, R.J.; Matzen, M.K.; Mock, R.C.; Nash, T.J.; Olson, R.E.; Peterson, D.L.; Ruggles, L.E.; Sanford, T.W.L.; Simpson, W.W.; Struve, K.W.; Vesey, R.A.

    1999-06-16

    Hohlraums (measuring 6-mm in diameter by 7-mm in height) have been heated by x-rays from a z-pinch. Over measured x-ray input powers P of 0.7 to 13 TW, the hohlraum radiation temperature T increases from {approximately}55 to {approximately}130 eV, and is in agreement with the Planckian relation P-T{sup 4}. The results suggest that indirect-drive ICF studies involving NIF relevant pulse shapes and <2-mm diameter capsules can he studied using this arrangement.

  16. X-ray crystallography

    NASA Technical Reports Server (NTRS)

    2001-01-01

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

  17. Tunable X-ray source

    DOEpatents

    Boyce, James R.

    2011-02-08

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

  18. Generation of attosecond x-ray pulses with a multi-cycle two-color ESASE scheme

    SciTech Connect

    Ding, Y.; Huang, Z.; Ratner, D.; Bucksbaum, P.; Merdji, H.; /Saclay /SLAC

    2009-03-04

    Generation of attosecond x-ray pulses is attracting much attention within the x-ray free-electron laser (FEL) user community. Several schemes using extremely short laser pulses to manipulate the electron bunches have been proposed. In this paper, we extend the attosecond two-color ESASE scheme proposed by Zholents et al. to the long optical cycle regime using a second detuned laser and a tapered undulator. Both lasers can be about ten-optical-cycles long, with the second laser frequency detuned from the first to optimize the contrast between the central and side current spikes. A tapered undulator mitigates the degradation effect of the longitudinal space charge (LSC) force in the undulator and suppresses the FEL gain of all side current peaks. Simulations using the LCLS parameters show a single attosecond x-ray spike of {approx} 110 attoseconds can be produced. The second laser can also be detuned to coherently control the number of the side x-ray spikes and the length of the radiation pulse.

  19. An RIP-based evaluation method for candidate next generation cardiac CT architectures with carbon nanotube x-ray source

    NASA Astrophysics Data System (ADS)

    Liu, Baodong; Wang, Ge; De Man, Bruno; Krupinski, Elizabeth; Yu, Hengyong

    2012-10-01

    Despite impressive advancements in computed tomography (CT) technology in recent years, there are still critical and immediate needs in cardiac CT in terms of high spatial resolution, high temporal resolution and low radiation dose. Because carbon nanotube (CNT) x-ray sources can be compactly integrated, this technology can be used for multisource or stationary system to improve temporal resolution. To avoid the rotation of x-ray source, a lot of source-detector pairs are needed in a stationary CNT-based x-ray system. Limited by the space and costs, the number of source-detector pairs could not be too large, which results in a few-view scan problem. The reconstruction can be modeled as a l1-norm minimization problem, which usually can be solved by compressive sensing (CS) based algorithms. To evaluate the data completeness of candidate next generation cardiac CT architectures with CNT x-ray source, based on the fact that smaller restricted isometry property (RIP) constants lead to a better l1-norm recovery, we construct a measurement related to the RIP constants. The results show that the proposed RIP-based evaluation method coincides with the known CT reconstruction theory. This method is simple and easy to be implemented for different CT scan architectures, and it provides a practical tool to evaluate the data completeness in the framework of l1-norm recovery theory without a specific CS-based reconstruction algorithm.

  20. Specific features of X-ray generation by plasma focus chambers with deuterium and deuterium-tritium fillings

    NASA Astrophysics Data System (ADS)

    Dulatov, A. K.; Krapiva, P. S.; Lemeshko, B. D.; Mikhailov, Yu. V.; Moskalenko, I. N.; Prokuratov, I. A.; Selifanov, A. N.

    2016-01-01

    The process of hard X-ray (HXR) generation in plasma focus (PF) chambers was studied experimentally. The radiation was recorded using scintillation detectors with a high time resolution and thermoluminescent detectors in combination with the method of absorbing filters. Time-resolved analysis of the processes of neutron and X-ray generation in PFs is performed. The spectra of HXR emission from PF chambers with deuterium and deuterium-tritium fillings are determined. In experiments with PF chambers filled with a deuterium-tritium mixture, in addition to the HXR pulse with photon energies of up to 200-300 keV, a γ-ray pulse with photon energies of up to 2.5-3.0 MeV is recorded, and a mechanism of its generation is proposed.

  1. Generating Ultrashort Coherent Soft X-ray Radiation in Storage Rings Using Angular-modulated Electron Beams

    SciTech Connect

    Xiang, D.; Wan, W.; /LBL, Berkeley

    2010-08-23

    A technique is proposed to generate ultrashort coherent soft x-ray radiation in storage rings using angular-modulated electron beams. In the scheme a laser operating in the TEM01 mode is first used to modulate the angular distribution of the electron beam in an undulator. After passing through a special beam line with non-zero transfer matrix element R{sub 54}, the angular modulation is converted to density modulation which contains considerable higher harmonic contents of the laser. It is found that the harmonic number can be one or two orders of magnitude higher than the standard coherent harmonic generation method which relies on beam energy modulation. The technique has the potential of generating femtosecond coherent soft x-ray radiation directly from an infrared seed laser and may open new research opportunities for ultrafast sciences in storage rings.

  2. X-ray generation in cryogenic targets irradiated by 1 {mu}m pulse laser

    SciTech Connect

    Shimoura, A.; Amano, S.; Miyamoto, S.; Mochizuki, T.

    1998-01-01

    Soft x-ray spectral radiations from Xe, H{sub 2}O, and CO{sub 2} cryogenic targets irradiated by a 1 {mu}m neodymium doped YAG-slab laser at pulse widths of 12{endash}20 ns and at laser intensities of 5{times}10{sup 10}{endash}10{sup 12}W/cm{sup 2} have been observed. These targets radiate soft x-rays in a wavelength range of 10{endash}13 nm which is useful for projection microlithography. We have found a strong x-ray spectral peak at {lambda}=10.8nm with a Xe cryogenic target. The measured x-ray conversion efficiency with the Xe target was 0.8{percent}/sr({lambda}=10.8{plus_minus}0.27nm) at a laser intensity of 1{times}10{sup 12}W/cm{sup 2}. This was ten times or more efficient than that with H{sub 2}O and CO{sub 2} targets. {copyright} {ital 1998 American Institute of Physics.}

  3. Simbol-X: A New Generation Soft/Hard X-ray Telescope

    NASA Astrophysics Data System (ADS)

    Slane, Patrick O.; Romaine, S.; Murray, S. S.; Brissenden, R.; Elvis, M.; Gorenstein, P.; Steel, S.; O'Dell, S.; Kolodziejczak, J.; Ramsey, B.; Angelini, L.; Citterio, O.; Pareschi, G.

    2008-03-01

    Simbol-X is arguably the most powerful broad-band focusing hard (0.5-80 keV) X-ray telescope operating in the 2013 timeframe. The combination of good angular resolution, broad energy response, and efficient observing provided by a good field of view and high orbit will provide a very large increase in sensitivity in a hitherto relatively unexplored spectral region. This will enable key scientific investigations including a census of supermassive black holes in the crucial energy range in which the cosmic X-ray background peaks, measurements of the geometry and dynamics of accretion in black hole binaries, characterization of hard X-ray sources in the Galactic center, and the nature and origin of energetic particles in galaxy clusters and supernova remnants. Its single optics module contains a set of nested nickel shells coated with multilayers to boost the high-energy response and the field of view. Its focal plane detectors are a novel hybrid configuration, with thick-depletion silicon providing the low energy response, and Cadmium Telluride the high energy response. To achieve the long focal length necessary for large collecting areas at high energies, the optics and detectors are on separate high-earth-orbit formation-flying spacecrafts, 20 m apart. We describe a proposed US participation in the Simbol-X program to provide technical expertise in the area of multilayer coatings for the X-ray optics; expertise in science and the X-ray testing and calibration of the flight optics; and support as a data analysis, Guest Investigator, and archiving center. The use of the NASA DSN Goldstone station, as a complement to the Malindi tracking station,will also be provided.

  4. Characterisation of flash X-ray source generated by Kali-1000 Pulse Power System

    NASA Astrophysics Data System (ADS)

    Satyanarayana, N.; Durga Prasada Rao, A.; Mittal, K. C.

    2016-02-01

    The electron beam-driven Rod Pinch Diode (RPD) is presently fielded on KALI-1000 Pulse Power System at Bhabha Atomic Research Centre, Visakhapatnam and is a leading candidate for future flash X-ray radiographic sources. The diode is capable of producing less than 2-mm radiation spot sizes and greater than 350 milli rads of dose measured at 1 m from the X-ray source. KALI-1000 Pulse Power Source is capable of delivering up to 600 kV using a Tesla Transformer with Demineralized Insulated Transmission Line (DITL), the diode typically operates between 250-330 kV . Since the radiation dose has a power-law dependence on diode voltage, this limits the dose production on KALI-1000 system. Radiation dose with angular variation is measured using thermoluminescent detectors (TLD's) and the X-ray spot size is measured using pin hole arrangement with image plate (IP) to obtain the time-integrated source profile as well as a time-resolved spot diagnostic. An X-ray pinhole camera was used to pick out where the energetic e-beam connects to the anode. Ideally the diode should function such that the radiation is emitted from the tip. The camera was mounted perpendicular to the machine's axis to view the radiation from the tip. Comparison of the spot sizes of the X-ray sources obtained by the pin hole and rolled edge arrangements was carried and results obtained by both the techniques are with in ± 10% of the average values.

  5. X-ray contact microscopy using a plasma source generated by long and short (120ns and 10ns) excimer laser pulses

    SciTech Connect

    Cotton, R.; Bollanti, S.; Di Lazzaro, P.

    1995-12-31

    Soft X-ray contact microscopy (SXCM), using a pulsed X-ray source, offers the possibility of imaging the ultrastructure of living biological systems at sub-50nm resolution. The authors have developed a pulsed plasma X-ray source for this application, generated by the large volume XeCl laser Hercules. Various unstable optical resonator configurations were employed to achieve a high laser intensity to increase the conversion efficiency to water window X-rays (280--530 eV). Optimum plasma conditions for SXCM are discussed, including the effect of pulse duration on image resolution. Soft X-ray contact images of Chlamydomonas dysosmos (unicellular alga) and the cyanobacteria Leptolyngbya are shown. In addition, the potential of producing a movie film of the development of X-ray images within the photoresist (acting as the recording medium) is discussed, following the resist development while viewing by atomic force microscopy.

  6. First results of KALI-30 GW with 1 MV flash X-rays generation and characterization by Imaging plate

    NASA Astrophysics Data System (ADS)

    Sharma, A.; Shaikh, A. M.; Senthil, K.; Mitra, S.; Chandra, R.; Vishnu, S.; Sandeep, S.; Roy, A.; Rakhee, M.; Sharma, V.; Danish, M. B.; Kolge, T. S.; Ranjeet, K.; Agrawal, R.; Saroj, P. C.; Tewari, S. V.; Mittal, K. C.

    2014-07-01

    The design, development and commissioning of 1 MV pulsed electron accelerator producing Flash X-Rays is described in this paper. This pulsed power system is based on bipolar MARX generator and Blumlein followed by Explosive electron emission diode assembly. The peak pulsed power is ~ 30 GW. The electron energies in the range of 400 keV to 1030 keV are produced and delivered to experimental load of Industrial diode. Electrons are emitted from a stainless steel ring at ground potential by explosive field emission and bombard the anode tungsten pin for flash X-rays generation. The relativistic electron beam has been simulated within the diode chamber and pattern shows the beam propagation. Imaging plates are used to characterize the source size and optimization has been reported.

  7. Effect of a pulsating electric field on ECR heating in the CERA-RX(C) X-ray generator

    NASA Astrophysics Data System (ADS)

    Balmashnov, A. A.; Kalashnikov, A. V.; Kalashnikov, V. V.; Stepina, S. P.; Umnov, A. M.

    2016-03-01

    3D particle-in-cell plasma simulations for the field configurations implemented in the CERA-RX(C) ECR X-ray generator (2.45 GHz) have been conducted. Dependences of the energy spectra of electrons incident on the target electrode on the amplitude and frequency of pulsations of the electric field in a megahertz range are derived. The simulation data are compared with the results of the full-scale experiment.

  8. Generation of ultra-large-bandwidth X-ray free-electron-laser pulses with a transverse-gradient undulator.

    PubMed

    Prat, Eduard; Calvi, Marco; Reiche, Sven

    2016-07-01

    A new and simple method to generate X-ray free-electron-laser radiation with unprecedented spectral bandwidth above the 10% level is presented. The broad bandwidth is achieved by sending a transversely tilted beam through a transverse-gradient undulator. The extent of the bandwidth can easily be controlled by variation of the beam tilt or the undulator gradient. Numerical simulations confirm the validity and feasibility of this method. PMID:27359135

  9. Chest x-ray

    MedlinePlus

    ... Images Aortic rupture, chest x-ray Lung cancer, frontal chest x-ray Adenocarcinoma - chest x-ray Coal ... cancer - chest x-ray Lung nodule, right middle lobe - chest x-ray Lung mass, right upper lung - ...

  10. Simultaneous generation of quasi-monoenergetic electron and betatron X-rays from nitrogen gas via ionization injection

    SciTech Connect

    Huang, K.; Yan, W. C.; Li, M. H.; Tao, M. Z.; Ma, Y.; Zhao, J. R.; Chen, L. M.; Li, D. Z.; Chen, Z. Y.; Ge, X. L.; Liu, F.; Hafz, N. M.; Zhang, J.

    2014-11-17

    Upon the interaction of 60 TW Ti: sapphire laser pulses with 4 mm long supersonic nitrogen gas jet, a directional x-ray emission was generated along with the generation of stable quasi-monoenergetic electron beams having a peak energy of 130 MeV and a relative energy spread of ∼ 20%. The betatron x-ray emission had a small divergence of 7.5 mrad and a critical energy of 4 keV. The laser wakefield acceleration process was stimulated in a background plasma density of merely 5.4 × 10{sup 17 }cm{sup −3} utilizing ionization injection. The non-self-focusing and stable propagation of the laser pulse in the pure nitrogen gaseous plasma should be responsible for the simultaneous generation of the high-quality X-ray and electron beams. Those ultra-short and naturally-synchronized beams could be applicable to ultrafast pump-probe experiments.

  11. Balloon-borne measurements of aurorally generated X-rays, electric fields and infrasonic waves

    NASA Astrophysics Data System (ADS)

    Slamanig, H.; Friedrich, M.

    1981-12-01

    The block diagram of an integrated ballon payload for measuring X-rays, electric fields and rapid temperature variations is presented. Bremsstrahlung X-rays are measured by an uncollimated scintillation counter whose crystal is optically connected to a photomultiplier. Almost 100% efficiency up to 200 keV is achieved. The electric field probes are 20 cm dia aluminum spheres mounted on four booms. Horizontal field is derived from the voltage difference between the upper pair; orthogonal field is calculated from the lower pair. Temperatures are derived by measuring the phase of a continously radiating acoustic transmitter, using two microphones placed 30 and 120 cm from it. A photometer with a spectral response peak at 400 + or - 20 nm detects optical auroras. An electronic card determines pressure, payload temperature, battery voltage and balloon location. A slow PCM telemetry system is used.

  12. Atomic Data Needs for the New Generation of X-ray Observatories

    NASA Astrophysics Data System (ADS)

    Garcia, Javier; 6174967980

    2016-06-01

    Modeling X-ray spectra produced by photoionized plasmas is crucial for the physical interpretation of many astrophysical sources. These models rely on theoretical and numerical techniques, but importantly also on the availability of reliable atomic data. The need for accurate data continues to grow with the advent of new and more sensitive instruments. I will describe atomic-data requirements for addressing three astrophysical problems: (1) atomic, molecular, and dust absorption in the ISM; (2) detection and characterization of inner-shell lines from various trace elements or Fe-peak elements (e.g., P, K, Cr, Mn, Co); and (3) modeling X-ray spectra reflected from black hole accretion disks in the high-density limit. I will discuss the importance ofthese studies, and the limitations of the theoretical models presently being used to fit data from such current missions as NuSTAR and Astro-H (Hitomi).

  13. Suppression of X-rays generated by runaway electrons in ATF

    NASA Astrophysics Data System (ADS)

    Rasmussen, D. A.; England, A. C.; Eberle, C. C.; Devan, W. R.; Harris, J. H.; Jernigan, T. C.; Kindsfather, R. R.; Morris, R. N.; Murakami, M.; Neilson, G. H.

    X-ray emission from runaway electrons on ATF is a serious issue. Runaway suppression techniques used on Heliotron-E are not adequate for ATF. Three approaches have been developed to suppress runaway production. Monitoring devices have been installed in occupied areas and personnel access and exposure will be limited. Additional shielding will be added as required. These systems will be ready for installation and testing on ATF prior to commissioning or first plasma operation.

  14. Instrumentation for a next-generation x-ray all-sky monitor

    SciTech Connect

    Peele, A. G.

    1999-12-15

    We have proposed an x-ray all-sky monitor for a small satellite mission that will be ten times more sensitive than past monitors and that opens up a new band of the soft x-ray spectrum (0.1-3.0 keV) for study. We discuss three approaches to the construction of the optics. The first method, well within the reach of existing technology, is to approximate the lobster-eye geometry by building crossed arrays of planar reflectors, this gives great control over the reflecting surface but is limited in terms of resolution at the baseline 4 arc minute level. The second method is to use microchannel plates; this technology has the potential to greatly exceed the baseline resolution and sensitivity but is yet to be fully demonstrated. The third method, while still in its infancy, may yet prove to be the most powerful; this approach relies on photolithography to expose a substrate that can then be developed and replicated. The scientific case for this mission is almost too broad to state here. The instrument we describe will allow investigation of the long term light curves of thousands of AGN, it will detect thousands of transients, including GRBs and type II supernova, and the stellar coronae of hundreds of the brightest x-ray stars can be monitored. In addition the classical objectives of all-sky monitors--long-term all-sky archive and watchdog alert to new events--will be fulfilled at an unprecedented level. We also note that by opening up a little-explored band of the x-ray sky the opportunity for new discovery is presented. A satisfying example of entering new territory while still retaining the guarantee of expanding the domain of existing research.

  15. Instrumentation for a next-generation x-ray all-sky monitor

    NASA Astrophysics Data System (ADS)

    Peele, A. G.

    1999-12-01

    We have proposed an x-ray all-sky monitor for a small satellite mission that will be ten times more sensitive than past monitors and that opens up a new band of the soft x-ray spectrum (0.1-3.0 keV) for study. We discuss three approaches to the construction of the optics. The first method, well within the reach of existing technology, is to approximate the lobster-eye geometry by building crossed arrays of planar reflectors, this gives great control over the reflecting surface but is limited in terms of resolution at the baseline 4 arc minute level. The second method is to use microchannel plates; this technology has the potential to greatly exceed the baseline resolution and sensitivity but is yet to be fully demonstrated. The third method, while still in its infancy, may yet prove to be the most powerful; this approach relies on photolithography to expose a substrate that can then be developed and replicated. The scientific case for this mission is almost too broad to state here. The instrument we describe will allow investigation of the long term light curves of thousands of AGN, it will detect thousands of transients, including GRBs and type II supernova, and the stellar coronae of hundreds of the brightest x-ray stars can be monitored. In addition the classical objectives of all-sky monitors-long-term all-sky archive and watchdog alert to new events-will be fulfilled at an unprecedented level. We also note that by opening up a little-explored band of the x-ray sky the opportunity for new discovery is presented. A satisfying example of entering new territory while still retaining the guarantee of expanding the domain of existing research.

  16. Repetitive flash x-ray generator utilizing a simple diode with a new type of energy-selective function

    NASA Astrophysics Data System (ADS)

    Sato, E.; Kimura, S.; Kawasaki, S.; Isobe, H.; Takahashi, K.; Tamakawa, Y.; Yanagisawa, T.

    1990-09-01

    The construction and the fundamental studies of a repetitive flash x-ray generator having a simple diode with an energy-selective function are described. This generator consisted of the following components: a constant high-voltage power supply, a high-voltage pulser, a repetitive high-energy impulse switching system, a turbo molecular pump, and a flash x-ray tube. The circuit of this pulser employed a modified two-stage surge Marx generator with a capacity during main discharge of 425pF. The x-ray tube was of the demountable-diode type which was connected to the turbo molecular pump and consisted of the following major devices: a rod-shaped anode tip made of tungsten, a disk cathode made of graphite, an aluminum filter, and a tube body made of glass. Two condensers inside of the pulser were charged from 40 to 60 kV, and the output voltage was about 1.9 times the charging voltage. The peak tube voltage was primarily determined by the anode-cathode (A-C) space, and the peak tube current was less than 0.6 kA. The peak tube voltage slightly increased when the charging voltage was increased, but the amount of change rate was small. Thus, the maximum photon energy could be easily controlled by varying the A-C space. The pulse width ranged from 40 to 100 ns, and the x-ray intensity was less than 1.0 μC/kg at 0.3 m per pulse. The repetitive frequency was less than 50 Hz, and the effective focal spot size was determined by the diameter of the anode tip and ranged from 0.5 to 3.0 mm in diameter.

  17. Relativistically Self-Channeled Femtosecond Terawatt Lasers for High-Field Physics and X-Ray Generation

    SciTech Connect

    Borisov, A.B.; Boyer, K.; Cameron, S.M.; Luk, T.S.; McPherson, A.; Nelson, T.; Rhodes, C.K.

    1999-01-01

    Optical channeling or refractive guiding processes involving the nonlinear interaction of intense femtosecond optical pulses with matter in the self-focussing regime has created exciting opportunities for next-generation laser plasma-based x-ray sources and directed energy applications. This fundamentally new form of extended paraxial electromagnetic propagation in nonlinear dispersive media such as underdense plasma is attributed to the interplay between normal optical diffraction and intensity-dependent nonlinear focussing and refraction contributions in the dielectric response. Superposition of these mechanisms on the intrinsic index profile acts to confine the propagating energy in a dynamic self-guiding longitudinal waveguide structure which is stable for power transmission and robust compression. The laser-driven channels are hypothesized to support a degree of solitonic transport behavior, simultaneously stable in the space and time domains (group velocity dispersion balances self-phase modulation), and are believed to be self-compensating for diffraction and dispersion over many Rayleigh lengths in contrast with the defining characteristics of conventional diffractive imaging and beamforming. By combining concentrated power deposition with well-ordered spatial localization, this phenomena will also create new possibilities for production and regulation of physical interactions, including electron beams, enhanced material coupling, and self-modulated plasma wakefields, over extended gain distances with unprecedented energy densities. Harmonious combination of short-pulse x-ray production with plasma channeling resulting from a relativistic charge displacement nonlinearity mechanism in the terawatt regime (10{sup 18} W/cm{sup 2}) has been shown to generate high-field conditions conducive to efficient multi-kilovolt x-ray amplification and peak spectral brightness. Channeled optical propagation with intense short-pulse lasers is expected to impact several

  18. Double-confocal resonator for X-ray generation via intracavity Thomson scattering

    SciTech Connect

    Xie, M.

    1995-12-31

    There has been a growing interest in developing compact X-ray sources through Thomson scattering of a laser beam by a relativistic electron beam. For higher X-ray flux it is desirable to have the scattering to occur inside an optical resonator where the laser power is higher. In this paper I propose a double-confocal resonator design optimized for head-on Thomson scattering inside an FEL oscillator and analyze its performance taking into account the diffraction and FEL gain. A double confocal resonator is equivalent to two confocal resonators in series. Such a resonator has several advantages: it couples electron beam through and X-ray out of the cavity with holes on cavity mirrors, thus allowing the system to be compact; it supports the FEL mode with minimal diffraction loss through the holes; it provides a laser focus in the forward direction for a better mode overlap with the electron beam; and it provides a focus at the same location in the backward direction for higher Thomson scattering efficiency; in addition, the mode size at the focal point and hence the Rayleigh range can be adjusted simply through intracavity apertures; furthermore, it gives a large mode size at the mirrors to reduce power loading. Simulations as well as analytical results will be presented. Also other configurations of intracavity Thomson scattering where the double-confocal resonator could be useful will be discussed.

  19. SuperHERO: The Next Generation Hard X-ray HEROES Telescope

    NASA Technical Reports Server (NTRS)

    Gaskin, Jessica A.; Christe, Steven D.; Wilson-Hodge, Colleen; Shih, Albert Y. M.; Ramsey, Brian D.; Tennant, Allyn F.; Swartz, Douglas A.

    2014-01-01

    SuperHERO is a new high-sensitivity Long Duration Balloon (LDB)-capable, hard-x-ray (20-75 keV) telescope for making novel astrophysics and heliophysics observations. The proposed SuperHERO payload will be developed jointly by the Astrophysics Office at NASA Marshall Space Flight Center, the Solar Physics Laboratory and Wallops Flight Facility at NASA Goddard Space Flight Center. SuperHERO is a follow-on payload to the High Energy Replicated Optics to Explore the Sun (HEROES) balloon-borne telescope that recently launched from Fort Sumner, NM in September of 2013. The HEROES core instrument is a hard x-ray telescope consisting of x-ray 109 optics configured into 8 modules. Each module is aligned to a matching gas-filled detector at a focal length of 6 m. SuperHERO will make significant improvements to the HEROES payload, including: new solid-state multi-pixel CdTe detectors, additional optics, the Wallops Arc-Second Pointer, alignment monitoring systems and lighter gondola.

  20. SuperHERO: The Next Generation Hard X-Ray HEROES Telescope

    NASA Technical Reports Server (NTRS)

    Wilson-Hodge, Colleen A.; Gaskin, Jessica A.; Christe, Steven D.; Elsner, Ronald F.; Ramsey, Brian D.; Seller, Paul; Shih, Albert Y.; Stuchlik, David W.; Swartz, Douglas A.; Tenant, Allyn F.; Wilson, Matthew D.

    2014-01-01

    SuperHERO is a new high-sensitivity Long Duration Balloon (LDB)-capable, hard-x-ray (20-75 keV) telescope for making novel astrophysics and heliophysics observations. The proposed SuperHERO payload will be developed jointly by the Astrophysics Office at NASA Marshall Space Flight Center, the Solar Physics Laboratory and Wallops Flight Facility at NASA Goddard Space Flight Center. SuperHERO is a follow-on payload to the High Energy Replicated Optics to Explore the Sun (HEROES) balloon-borne telescope that recently launched from Fort Sumner, NM in September of 2013. The HEROES core instrument is a hard x-ray telescope consisting of x-ray 109 optics configured into 8 modules. Each module is aligned to a matching gas-filled detector at a focal length of 6 m. SuperHERO will make significant improvements to the HEROES payload, including: new solid-state multi-pixel CdTe detectors, additional optics, the Wallops Arc-Second Pointer, alignment monitoring systems and lighter gondola.

  1. Dynamics and X-ray emission of an X-pinch conducted on a small capacitive generator

    NASA Astrophysics Data System (ADS)

    Pavez, Cristian; Avaria, Gonzalo; Moreno, Jose; San Martin, Patricio; Soto, Leopoldo; Sepulveda, Adolfo; Pedreros, Jose

    2014-10-01

    The characterization of the dynamics and X-ray emission of a X-pinch configuration conducted in a compact capacitive generator are presented. The experimental measurements were carried out on a multi-purpose generator (1.2 micro F, 345 J, 47.5 nH, T/4 = 375 ns and Z = 0.2 Ohm in short circuit) which produces currents up to 122 kA with 500 ns quarter period, when wire load are used. Dark-field Schlieren and interferometry techniques were used to characterize the dynamics of the precursor plasma, plasma flares and plasma jet on the axes. The X-ray emission and the source size are evaluated with filtered PIN-diodes and aperture imaging technique respectively. In addition, X-ray plasma imaging and radiographic applications are presented. The experiments were conducted on W wires of different diameters. The experimental observations show a similar dynamic to those observed in experiments of higher current and shorter quarter period. Work supported by PIA CONICYT Grant ACT-1115, PAI CONICYT 791100020 and FONDECYT Iniciacion 11121587.

  2. Tunable coherent radiation at soft X-ray wavelengths: Generation and interferometric applications

    SciTech Connect

    Rosfjord, Kristine Marie

    2004-07-01

    The availability of high power, spectrally and spatially coherent soft x-rays (SXR) would facilitate a wide variety of experiments as this energy region covers the primary resonances of many magnetic and biological materials. Specifically, there are the carbon and oxygen K-edges that are critical for biological imaging in the water window and the L-edges of iron, nickel, and cobalt for which imaging and scattering studies can be performed. A new coherent soft X-ray branchline at the Advanced Light Source has begun operation (beamline 12.0.2). Using the third harmonic from an 8 cm period undulator, this branch delivers coherent soft x-rays with photon energies ranging from 200eV to 1keV. This branchline is composed of two sub-branches one at 14X demagnification and the other 8X demagnification. The former is optimized for use at 500eV and the latter at 800eV. Here the expected power from the third harmonic of this undulator and the beamline design and characterization is presented. The characterization includes measurements on available photon flux as well as a series of double pinhole experiments to determine the coherence factor with respect to transverse distance. The first high quality Airy patterns at SXR wavelengths are created with this new beamline. The operation of this new beamline allows for interferometry to be performed in the SXR region. Here an interferometric experiment designed to directly determine the index of refraction of a material under test is performed. Measurements are first made in the EUV region using an established beamline (beamline12.0.1) to measure silicon, ruthenium and tantalum silicon nitride. This work is then extended to the SXR region using beamline 12.0.2 to test chromium and vanadium.

  3. Two-Chicane Compressed Harmonic Generation of Soft X-Rays

    SciTech Connect

    Ratner, Daniel; Huang, Z.; Chao, A.; /SLAC

    2010-07-30

    We propose a simple single-stage scheme to produce fully coherent 3nm radiation. Seeding an electron bunch prior to compression simultaneously shortens the laser wavelength and duration, and increases the modulation amplitude. The final X-ray wavelength is tunable by controlling the compression factor with the RF phase. We propose a two chicane scheme that allows for nearly arbitrary modulation amplitudes, extending the method to photocathode beams. We also show that transportation of fine compressed modulation structure is feasible due to a canceling effect of the second chicane.

  4. A new generation of detectors for scanning x-ray beam imaging systems

    NASA Astrophysics Data System (ADS)

    Rommel, J. Martin

    2016-01-01

    Scanning x-ray beam imaging systems were first developed by American Science and Engineering, Inc. (AS&E) in the early 1970s [1]. Since then, these systems have found a wide range of applications in security inspection and non-destructive testing. Large-area detectors are most frequently used to collect backscattered radiation but smaller transmission detectors are also employed for selected applications. Until recently, only two basic detector designs have been used: large scintillator blocks with attached photomultiplier tubes (PMTs) or large-volume light-sealed boxes, lined with scintillating screens and port windows for PMTs. In both cases, the detectors have required considerable depth to provide acceptable light collection efficiency. A new design recently developed by AS&E relies on wavelength shifting fibres (WSF) for light collection. For the first time, this approach enables the construction of thin large-area detectors. Stacking layers of WSF ribbons and scintillating screens in varying combinations enables optimization of the detection efficiency for different applications. Taking separate readings from different layers provides an energy-sensitive signal combination. Energy sensitivity can be improved further by adding filtration between the signal channels. Several prototype configurations have been built and characterized for both backscatter and transmission imaging. A WSF-based detector has been commercialized for a transmission x-ray imaging application.

  5. Quasimonochromatic x-ray backlighting on the COrnell Beam Research Accelerator (COBRA) pulsed power generator

    SciTech Connect

    Knapp, P. F.; Greenly, J. B.; Gourdain, P. A.; Hoyt, C. L.; Pikuz, S. A.; Shelkovenko, T. A.; Hammer, D. A.

    2010-10-15

    Monochromatic x-ray backlighting has been employed with great success for imaging of plasmas with strong self-emission such as x-pinches and wire array z-pinches. However, implementation of a monochromatic backlighting system typically requires extremely high quality spherically bent crystals which are difficult to manufacture and can be prohibitively expensive. Furthermore, the crystal must have a direct line of sight to the object, which typically emits copious amounts of radiation and debris. We present a quasimonochromatic x-ray backlighting system which employs an elliptically bent mica crystal as the dispersive element. In this scheme a narrow band of continuum radiation is selected for imaging, instead of line radiation in the case of monochromatic imaging. The flat piece of mica is bent using a simple four-point bending apparatus that allows the curvature of the crystal to be adjusted in situ for imaging in the desired wavelength band. This system has the advantage that it is very cost effective, has a large aperture, and is extremely flexible. The principles of operation of the system are discussed and its performance is analyzed.

  6. NADPH oxidase-mediated generation of reactive oxygen species: A new mechanism for X-ray-induced HeLa cell death

    SciTech Connect

    Liu Qing; He Xiaoqing; Liu Yongsheng; Du Bingbing; Wang Xiaoyan; Zhang Weisheng; Jia Pengfei; Dong Jingmei; Ma Jianxiu; Wang Xiaohu; Li Sha; Zhang Hong

    2008-12-19

    Oxidative damage is an important mechanism in X-ray-induced cell death. Radiolysis of water molecules is a source of reactive oxygen species (ROS) that contribute to X-ray-induced cell death. In this study, we showed by ROS detection and a cell survival assay that NADPH oxidase has a very important role in X-ray-induced cell death. Under X-ray irradiation, the upregulation of the expression of NADPH oxidase membrane subunit gp91{sup phox} was dose-dependent. Meanwhile, the cytoplasmic subunit p47{sup phox} was translocated to the cell membrane and localized with p22{sup phox} and gp91{sup phox} to form reactive NADPH oxidase. Our data suggest, for the first time, that NADPH oxidase-mediated generation of ROS is an important contributor to X-ray-induced cell death. This suggests a new target for combined gene transfer and radiotherapy.

  7. (Cd,Mn)Te detectors for characterization of x-ray emissions generated during laser-driven fusion experiments

    SciTech Connect

    Cross,A.S.; Knauer, J. P.; Mycielski, A.; Kochanowska, D.; Wiktowska-Baran, M.; Jakiela, R.; Domagala, J.; Cui, Y.; James, R.; Sobolewski, R.

    2008-10-19

    We present our measurements of (Cd,Mn)Te photoconductive detectors (PCDs), fabricated for the goal of measuring both the temporal and spectral dependences of X-ray emissions generated from laser-illuminated targets during the inertial confinement fusion experiments. Our Cd{sub 1-x}Mn{sub x}Te (x = 0.05) single crystals, doped with V, were grown using a vertical Bridgman method and, subsequently, annealed in Cd for the highest resistivity ({approx}10{sup 10} {Omega}cm) and a good mobility-lifetime product ({approx}10{sup -3} cm{sup 2}/V). The 1-mm- and 2.3-mm-thick detectors were placed in the same housing as two 1-mm-thick diamond PCDs. All devices were pre-screened by a 7.6-mm-thick Be X-ray filter with a frequency cutoff of 1 keV. The incident shots from the OMEGA laser were 1-ns-long square pulses with energies ranging from 2.3 kJ to 22.6 kJ, and the PCDs were biased with 5000 V/cm. The response amplitudes and rise times of our (Cd,Mn)Te PCDs were comparable with the diamond detector performance, while the decay times were 4 to 10 times longer and in the 2-5 ns range. We observed two X-ray emission events separated by 1.24 ns. The first was identified as caused by heating of the target and creating a hot corona, while the second one was from the resulting compressed core. For comparison purposes, our testing was performed using {approx}1 keV X-ray photons, optimal for the diamond PCD. According to the presented simulations, however, at X-ray energies >10 keV diamond absorption efficiency drops to <50%, whereas for (Cd,Mn)Te the drop occurs at {approx}100 keV with near perfect, 100% absorption, up to 50 keV.

  8. Effects of Plant Cell Wall Matrix Polysaccharides on Bacterial Cellulose Structure Studied with Vibrational Sum Frequency Generation Spectroscopy and X-ray Diffraction

    SciTech Connect

    Park, Yong Bum; Lee, Christopher M; Kafle, Kabindra; Park, Sunkyu; Cosgrove, Daniel; Kim, Seong H

    2014-07-14

    The crystallinity, allomorph content, and mesoscale ordering of cellulose produced by Gluconacetobacter xylinus cultured with different plant cell wall matrix polysaccharides were studied with vibrational sum frequency generation (SFG) spectroscopy and X-ray diffraction (XRD).

  9. Supersonic Heat Wave Propagation in Laser-Produced Underdense Plasma for Efficient X-Ray Generation

    SciTech Connect

    Tanabe, M; Nishimura, H; Fujioka, S; Nagai, K; Iwamae, A; Ohnishi, N; Fournier, K B; Girard, F; Primout, M; Villette, B; Tobin, M; Mima, K

    2008-06-12

    We have observed supersonic heat wave propagation in a low-density aerogel target ({rho} {approx} 3.2 mg/cc) irradiated at the intensity of 4 x 10{sup 14} W/cm{sup 2}. The heat wave propagation was measured with a time-resolved x-ray imaging diagnostics, and the results were compared with simulations made with the two-dimensional radiation-hydrodynamic code, RAICHO. Propagation velocity of the ionization front gradually decreased as the wave propagates into the target. The reason of decrease is due to increase of laser absorption region as the front propagates and interplay of hydrodynamic motion and reflection of laser propagation. These features are well reported with the simulation.

  10. Arcus: The next generation of high-resolution X-ray grating spectra

    NASA Astrophysics Data System (ADS)

    Smith, Randall

    2014-11-01

    We present the design and scientific motivation for Arcus, an X-ray grating spectrometer mission to be deployed on the International Space Station. This mission will observe structure formation at and beyond the edges of clusters and galaxies, feedback from supermassive black holes, the structure of the interstellar medium and the formation and evolution of stars. Key mission requirements will be R>2500 and >600 cm^2 of effective area at the crucial O VII and O VIII lines, with the full bandpass going from 8-52Å, with an overall minimum resolution of 1300 and effective area >150 cm^2. We will use the silicon pore optics proposed for ESA's Athena mission, paired with off-plane gratings being developed at the University of Iowa and combined with MIT/Lincoln Labs CCDs.

  11. Evidence for Nanoparticles in Microwave-Generated Fireballs Observed by Synchrotron X-Ray Scattering

    NASA Astrophysics Data System (ADS)

    Mitchell, J. B. A.; Legarrec, J. L.; Sztucki, M.; Narayanan, T.; Dikhtyar, V.; Jerby, E.

    2008-02-01

    The small-angle x-ray scattering method has been applied to study fireballs ejected into the air from molten hot spots in borosilicate glass by localized microwaves [V. Dikhtyar and E. Jerby, Phys. Rev. Lett.PRLTAO0031-9007 96 045002 (2006)10.1103/PhysRevLett.96.045002]. The fireball’s particle size distribution, density, and decay rate in atmospheric pressure were measured. The results show that the fireballs contain particles with a mean size of ˜50nm with average number densities on the order of ˜109. Hence, fireballs can be considered as a dusty plasma which consists of an ensemble of charged nanoparticles in the plasma volume. This finding is likened to the ball-lightning phenomenon explained by the formation of an oxidizing particle network liberated by lightning striking the ground [J. Abrahamson and J. Dinniss, Nature (London)NATUAS0028-0836 403, 519 (2000)10.1038/35000525].

  12. Evidence for Nanoparticles in Microwave-Generated Fireballs Observed by Synchrotron X-Ray Scattering

    SciTech Connect

    Mitchell, J. B. A.; Le Garrec, J. L.; Sztucki, M.; Narayanan, T.; Dikhtyar, V.; Jerby, E.

    2008-02-15

    The small-angle x-ray scattering method has been applied to study fireballs ejected into the air from molten hot spots in borosilicate glass by localized microwaves [V. Dikhtyar and E. Jerby, Phys. Rev. Lett. 96 045002 (2006)]. The fireball's particle size distribution, density, and decay rate in atmospheric pressure were measured. The results show that the fireballs contain particles with a mean size of {approx}50 nm with average number densities on the order of {approx}10{sup 9}. Hence, fireballs can be considered as a dusty plasma which consists of an ensemble of charged nanoparticles in the plasma volume. This finding is likened to the ball-lightning phenomenon explained by the formation of an oxidizing particle network liberated by lightning striking the ground [J. Abrahamson and J. Dinniss, Nature (London) 403, 519 (2000)].

  13. Evidence for nanoparticles in microwave-generated fireballs observed by synchrotron x-ray scattering.

    PubMed

    Mitchell, J B A; LeGarrec, J L; Sztucki, M; Narayanan, T; Dikhtyar, V; Jerby, E

    2008-02-15

    The small-angle x-ray scattering method has been applied to study fireballs ejected into the air from molten hot spots in borosilicate glass by localized microwaves [V. Dikhtyar and E. Jerby, Phys. Rev. Lett. 96 045002 (2006)10.1103/PhysRevLett.96.045002]. The fireball's particle size distribution, density, and decay rate in atmospheric pressure were measured. The results show that the fireballs contain particles with a mean size of approximately 50 nm with average number densities on the order of approximately 10(9). Hence, fireballs can be considered as a dusty plasma which consists of an ensemble of charged nanoparticles in the plasma volume. This finding is likened to the ball-lightning phenomenon explained by the formation of an oxidizing particle network liberated by lightning striking the ground [J. Abrahamson and J. Dinniss, Nature (London) 403, 519 (2000)10.1038/35000525]. PMID:18352481

  14. Generation of X-rays and neutrons with a RF-discharge

    NASA Technical Reports Server (NTRS)

    Schneider, R. T.

    1982-01-01

    An experimental study concerning disk shaped plasma structures was performed. Such disk-shaped structures can be obtained using an rf discharge in hydrogen. The applied frequency was 1-2 Mhz. In case of operation in deuterium it was found that the discharge emits neutrons and X-rays, although the applied voltage is only 2 kV. This phenomenon was explained by assuming formation of plasma cavitons which are surrounded by high electric fields. The condition for formation of these cavitons is that the applied rf frequency is equal to the plasma frequency. The ions trapped in these resonance structures acquire sufficient energy that they can undergo fusion reactions with the ions in the surrounding gas.

  15. SuperHERO: the next generation hard x-ray HEROES telescope

    NASA Astrophysics Data System (ADS)

    Gaskin, Jessica A.; Christe, Steven D.; Elsner, Ronald F.; Kilaru, Kiranmayee; Ramsey, Brian D.; Seller, Paul; Shih, Albert Y.; Stuchlik, David W.; Swartz, Douglas A.; Tennant, Allyn F.; Weddendorf, Bruce; Wilson, Matthew D.; Wilson-Hodge, Colleen A.

    2014-07-01

    SuperHERO is a new high-resolution, Long Duration Balloon-capable, hard-x-ray (20-75 keV) focusing telescope for making novel astrophysics and heliophysics observations. The SuperHERO payload, currently in its proposal phase, is being developed jointly by the Astrophysics Office at NASA Marshall Space Flight Center and the Solar Physics Laboratory and the Wallops Flight Facility at NASA Goddard Space Flight Center. SuperHERO is a follow-on payload to the High Energy Replicated Optics to Explore the Sun (HEROES) balloon-borne telescope that recently flew from Fort Sumner, NM in September of 2013, and will utilize many of the same features. Significant enhancements to the HEROES payload will be made, including the addition of optics, novel solid-state multi-pixel CdTe detectors, integration of the Wallops Arc-Second Pointer and a significantly lighter gondola suitable for Long Duration Flights.

  16. Generation of coherent soft x-rays using a single-pass free-electron laser amplifier

    SciTech Connect

    Wang, T.F.; Goldstein, J.C.; Newnam, B.E.; McVey, B.D.

    1988-01-01

    We consider a single-pass free-electron laser (FEL) amplifier, driven by an rf-linac followed by a damping ring for reduced emittance, for use in generating coherent light in the soft x-ray region. The dependence of the optical gain on electron-beam quality, studied with the three-dimensional FEL simulation code FELEX, is given and related to the expected power of self-amplified spontaneous emission. We discuss issues for the damping ring designed to achieve the required electron beam quality. The idea of a multipass regenerative amplifier is also presented.

  17. In-pixel conversion with a 10 bit SAR ADC for next generation X-ray FELs

    NASA Astrophysics Data System (ADS)

    Lodola, L.; Batignani, G.; Benkechkache, M. A.; Bettarini, S.; Casarosa, G.; Comotti, D.; Dalla Betta, G. F.; Fabris, L.; Forti, F.; Grassi, M.; Latreche, S.; Malcovati, P.; Manghisoni, M.; Mendicino, R.; Morsani, F.; Paladino, A.; Pancheri, L.; Paoloni, E.; Ratti, L.; Re, V.; Rizzo, G.; Traversi, G.; Vacchi, C.; Verzellesi, G.; Xu, H.

    2016-07-01

    This work presents the design of an interleaved Successive Approximation Register (SAR) ADC, part of the readout channel for the PixFEL detector. The PixFEL project aims at substantially advancing the state-of-the-art in the field of 2D X-ray imaging for applications at the next generation Free Electron Laser (FEL) facilities. For this purpose, the collaboration is developing the fundamental microelectronic building blocks for the readout channel. This work focuses on the design of the ADC carried out in a 65 nm CMOS technology. To obtain a good tradeoff between power consumption, conversion speed and area occupation, an interleaved SAR ADC architecture was adopted.

  18. 4th Annual SATN Conference 2011: Curriculum Transformation at Universities of Technology: Towards Development of New Generation Universities

    ERIC Educational Resources Information Center

    Mthembu, T.

    2012-01-01

    The South African Technology Network (SATN) would like to thank the Editor of the "South African Journal of Higher Education" (SAJHE) for the opportunity to publish papers read at the 4th Annual SATN Conference that was hosted by Central University of Technology and held in Bloemfontein in November 2011. The journal makes it possible for…

  19. SuperHERO: The Next Generation Hard X-Ray Focusing Telescope

    NASA Astrophysics Data System (ADS)

    Gaskin, Jessica; Wilson-Hodge, Colleen; Ramsey, Brian; Elsner, Ronald; Tennant, Allyn F.; Kilaru, Kiranmayee; Swartz, Douglas A.; Christe, Steven; Shih, Albert Y.; Baganoff, Frederick K.; Seller, Paul; Wilson, Matthew; Stuchlik, David

    2015-01-01

    SuperHERO is a balloon-borne hard x-ray (20-75 keV) telescope that couples high-angular resolution (~20 arcsecs) electroformed-nickel grazing incidence optics to state-of-the-art fine pixel-pitch (250 µm) Cadmium-Telluride detectors with a 6 m focal length. This telescope, currently in the proposal phase, will have the highest angular resolution of any hard x-ray telescope to date, and comparable energy resolution to that of the Nuclear Spectroscopic Telescope Array. The high angular resolution afforded by focusing optics is essential for mitigating source confusion in crowded fields, for direct imaging of extended sources on fine spatial scales, and for efficient observing through greatly-increased sensitivity. As such, the primary astronomical targets are the Galactic Center, pulsar-powered synchrotron nebulae and diffusive shock accelerated sites in supernova remnants. To facilitate solar observations, the SuperHERO detectors have a high processing rate of ~10 kHz over the entire 80x80 pixel array, or over 5M photons per second over the detector area. The current SuperHERO configuration has a total on-axis effective area of 145 cm2 at 30 keV and a field of view of ~7 arcmin FWHM at 30 keV (simulated). The optics, developed at NASA Marshall Space Flight Center, have significant flight heritage as similar mirrors have flown on balloon payloads, sounding rockets and a satellite mission. The detectors, developed at Rutherford Appleton Laboratory (RAL), utilize the novel HEXITEC Application Specific Integrated Circuit. RAL has been working on these and similar detectors for over a decade for applications ranging from medical to defense. NASA Goddard Space Flight Center, working with RAL and MSFC has been adapting these detectors for flight, with good progress. The telescope will reside on a carbon-composite frame that will integrate the Wallops Arc Second Pointer. This design will allow for Long Duration Balloon flights from Antarctica that can last up to 4 weeks

  20. High-Flux Femtosecond X-Ray Emission from Controlled Generation of Annular Electron Beams in a Laser Wakefield Accelerator.

    PubMed

    Zhao, T Z; Behm, K; Dong, C F; Davoine, X; Kalmykov, S Y; Petrov, V; Chvykov, V; Cummings, P; Hou, B; Maksimchuk, A; Nees, J A; Yanovsky, V; Thomas, A G R; Krushelnick, K

    2016-08-26

    Annular quasimonoenergetic electron beams with a mean energy in the range 200-400 MeV and charge on the order of several picocoulombs were generated in a laser wakefield accelerator and subsequently accelerated using a plasma afterburner in a two-stage gas cell. Generation of these beams is associated with injection occurring on the density down ramp between the stages. This well-localized injection produces a bunch of electrons performing coherent betatron oscillations in the wakefield, resulting in a significant increase in the x-ray yield. Annular electron distributions are detected in 40% of shots under optimal conditions. Simultaneous control of the pulse duration and frequency chirp enables optimization of both the energy and the energy spread of the annular beam and boosts the radiant energy per unit charge by almost an order of magnitude. These well-defined annular distributions of electrons are a promising source of high-brightness laser plasma-based x rays. PMID:27610860

  1. Laser plasma cryogenic target on translating substrate for generation of continuously repetitive EUV and soft X-ray pulses

    SciTech Connect

    Amano, Sho

    2014-06-15

    To generate continuously repetitive EUV and soft X-ray pulses with various wavelengths from laser-produced plasmas, a one-dimensionally translating substrate system with a closed He gas cryostat that can continuously supply various cryogenic targets for ∼10 Hz laser pulses has been developed. The system was successfully operated at a lowest temperature of 15 K and at a maximum up-down speed of 12 mm/s. Solid Ar, Kr, and Xe layers were formed, and their growth rates and the laser crater sizes on them were studied. By optimization of the operational parameters in accordance with our design rule, it was shown that stable output power was achieved continuously from the plasma emission at frequencies of 1–10 Hz. The average soft X-ray and EUV powers obtained were 19 mW at 3.2 nm, 33 mW at 10.0 nm, and 66 mW at 10.8 nm, with 10% bandwidths, from the Ar, Kr, and Xe solid targets, respectively, with a laser power of 1 W. We will be able to achieve higher frequencies using a high beam quality laser that produces smaller craters, and can expect higher powers. Although only Ar, Kr, and Xe gases were tested in this study, the target system achieved a temperature of 15 K and can thus solidify almost all target gases, apart from H and He, and can continuously supply the solid target. The use of various target materials will enable expansion of the EUV and soft X-ray emission wavelength range.

  2. Femtosecond laser-induced hard X-ray generation in air from a solution flow of Au nano-sphere suspension using an automatic positioning system.

    PubMed

    Hsu, Wei-Hung; Masim, Frances Camille P; Porta, Matteo; Nguyen, Mai Thanh; Yonezawa, Tetsu; Balčytis, Armandas; Wang, Xuewen; Rosa, Lorenzo; Juodkazis, Saulius; Hatanaka, Koji

    2016-09-01

    Femtosecond laser-induced hard X-ray generation in air from a 100-µm-thick solution film of distilled water or Au nano-sphere suspension was carried out by using a newly-developed automatic positioning system with 1-µm precision. By positioning the solution film for the highest X-ray intensity, the optimum position shifted upstream as the laser power increased due to breakdown. Optimized positioning allowed us to control X-ray intensity with high fidelity. X-ray generation from Au nano-sphere suspension and distilled water showed different power scaling. Linear and nonlinear absorption mechanism are analyzed together with numerical modeling of light delivery. PMID:27607607

  3. Position Diagnostics For A Magnetic-Pinch Imploding Cylinder X-Ray Generator

    NASA Astrophysics Data System (ADS)

    Seagrave, J. D.; Woods, C. W.; Jones, L. A.

    1981-12-01

    Two diagnostic systems have been developed to assess the position and shape of a cylindrical imploding plasma sheath x-ray source. Both systems employ batteries of inexpensive nitrogen lasers. For measurement of the cylinder radius, eight 75-μJ, 1.2 -ns (FWHM) nitrogen lasers will form a series of narrow beams displaced parallel to the cylinder diameter. As the plasma implodes over a 2-μs period, these position-sampling lasers are fired in sequence at times expected to result in partial shadowing. The 2-cm wide beams strike a position-sensitive detector made up of a helical fiber-optic delay line of 2-mm pitch and 4-ns delay/turn. The clad plastic fiber is doped with Rhodamine B at the points where the 337.1-nm laser beams strike, and the fluorescent red flashes propagate along the optical delay line in both directions to avalanche photodiodes. One signal is displayed on a 5-MHz vertical raster; the other is displayed on four turns of a 2-MHz spiral sweep. The envelopes of both pulse trains are displayed on a conventional dual-beam scope. The nitrogen lasers are aligned axially and displaced radially by a system of mirrors. To assess the symmetry of the implosion, another battery of four nitrogen lasers is used to provide paraxially displaced multiple-image pinhole schlieren pictures.

  4. Automatic generation of 3D coronary artery centerlines using rotational X-ray angiography.

    PubMed

    Jandt, Uwe; Schäfer, Dirk; Grass, Michael; Rasche, Volker

    2009-12-01

    A fully automated 3D centerline modeling algorithm for coronary arteries is presented. It utilizes a subset of standard rotational X-ray angiography projections that correspond to one single cardiac phase. The algorithm is based on a fast marching approach, which selects voxels in 3D space that belong to the vascular structure and introduces a hierarchical order. The local 3D propagation speed is determined by a combination of corresponding 2D projections filtered with a vessel enhancing kernel. The best achievable accuracy of the algorithm is evaluated on simulated projections of a virtual heart phantom, showing that it is capable of extracting coronary centerlines with an accuracy that is mainly limited by projection and volume quantization (0.25 mm). The algorithm is reasonably insensitive to residual motion, which means that it is able to cope with inconsistencies within the projection data set caused by limited gating accuracy and respiration. Its accuracy on clinical data is evaluated based on expert ratings of extracted models of 17 consecutive clinical cases (10 LCA, 7 RCA). A success rate of 93.5% (i.e. with no or slight deviations) is achieved compared to 58.8% success rate of semi-automatically extracted models. PMID:19713148

  5. Efficient multi-keV x-ray source generated by nanosecond laser pulse irradiated multi-layer thin foils target

    SciTech Connect

    Tu, Shao-yong; Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang, Sichuan 621900 ; Hu, Guang-yue Zhao, Bin; Zheng, Jian; Miao, Wen-yong; Yuan, Yong-teng; Zhan, Xia-yu; Hou, Li-fei; Jiang, Shao-en; Ding, Yong-kun

    2014-04-15

    A new target configuration is proposed to generate efficient multi-keV x-ray source using multiple thin foils as x-ray emitters. The target was constructed with several layers of thin foils, which were placed with a specific, optimized spacing. The thin foils are burned though one by one by a nanosecond-long laser pulse, which produced a very large, hot, underdense plasma. One-dimensional radiation hydrodynamic simulations show that the emission region and the multi-keV x-ray flux generated by multi-layer thin foil target are similar to that of the low-density gas or foam target, which is currently a bright multi-keV x-ray source generated by laser heating. Detailed analysis of a range of foil thicknesses showed that a layer-thickness of 0.1 μm is thin enough to generate an efficient multi-keV x-ray source. Additionally, this type of target can be easily manufactured, compared with the complex techniques for fabrication of low-density foam targets. Our preliminary experimental results also verified that the size of multi-keV x-ray emission region could be enhanced significantly by using a multi-layer Ti thin foil target.

  6. Inner-Shell Photon-Ionized X-Ray Laser at 45(Angstrom)

    SciTech Connect

    Weber, F; Celliers, P; Moon, S; Snavely, R; Da Silva, L

    2002-02-01

    This report summarizes the major accomplishments of this three-year Laboratory Directed Research and Development (LDRD) Lab Wide (LW) project entitled, ''An Inner-Shell Photo-Ionized X-Ray Laser at 45 {angstrom}'', tracking code 99-LW-042. The most significant accomplishments of this project include the design of a suitable x-ray laser target, the invention of a measurement technique for the determination of rise times of x-ray pulses on the order of 50 femtoseconds, and a novel setup for generating a traveling wave with an ultrashort optical laser pulse. The pump probe technique for rise time measurement will allow us to detect ultrashort x-ray pulses, whose generation by means of a variety of 4th generation light sources is currently under planning elsewhere.

  7. Route to optimal generation of soft X-ray high harmonics with synthesized two-color laser pulses

    PubMed Central

    Jin, Cheng; Wang, Guoli; Le, Anh-Thu; Lin, C. D.

    2014-01-01

    High harmonics extending to X-rays have been generated from gases by intense lasers. To establish these coherent broadband radiations as an all-purpose tabletop light source for general applications in science and technology, new methods are needed to overcome the present low conversion efficiencies. Here we show that the conversion efficiency may be drastically increased with an optimized two-color pulse. By employing an optimally synthesized 2-µm mid-infrared laser and a small amount of its third harmonic, we show that harmonic yields from sub- to few-keV energy can be increased typically by ten-fold over the optimized single-color one. By combining with favorable phase-matching and together with the emerging high-repetition MHz mid-infrared lasers, we anticipate efficiency of harmonic yields can be increased by four to five orders in the near future, thus paving the way for employing high harmonics as useful broadband tabletop light sources from the extreme ultraviolet to the X-rays, as well as providing new tools for interrogating ultrafast dynamics of matter at attosecond timescales. PMID:25400015

  8. Focusing X-Ray Telescopes

    NASA Technical Reports Server (NTRS)

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

    2010-01-01

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

  9. 5-20 keV laser-induced x-ray generation at 1 kHz from a liquid-jet target

    NASA Astrophysics Data System (ADS)

    Tompkins, R. J.; Mercer, I. P.; Fettweis, M.; Barnett, C. J.; Klug, D. R.; Porter, Lord G.; Clark, I.; Jackson, S.; Matousek, P.; Parker, A. W.; Towrie, M.

    1998-09-01

    We report ultrashort pulse, 1 kHz repetition rate x-ray generation in the 5-20 keV spectral region, induced by the interaction of laser radiation with copper nitrate solution and ethylene glycol liquid-jet targets. The characteristics of the copper nitrate source are relevant for application to time-resolved x-ray diffraction studies as well as for spectroscopic x-ray absorption studies. The x-ray sources were operated uninterrupted for in excess of 5 h with no detectable buildup of debris on the associated optics. The x-ray flux generated by both sources is estimated to be of the order of 106photons s-1 sr-1 in the 5-20 keV region. The spectra have been measured with both a PIN photodiode, and with transmission measurements taken using aluminum filters. We find that the plasma emission has a broadband component attributed to bremsstrahlung emission, with the bulk of the x-ray emission emitted from the chamber lying between 5 and 20 keV for both sources. The copper nitrate emission, however, delivers a dominant emission peak at 9 keV, attributed to the characteristic K emission of copper.

  10. Generation and Propagation of a Picosecond Acoustic Pulse at a Buried Interface: Time-Resolved X-Ray Diffraction Measurements

    SciTech Connect

    Lee, S.H.; Cavalieri, A.L.; Fritz, D.M.; Swan, M.C.; Reis, D.A.; Hegde, R.S.; Reason, M.; Goldman, R.S.

    2005-12-09

    We report on the propagation of coherent acoustic wave packets in (001) surface oriented Al{sub 0.3}Ga{sub 0.7}As/GaAs heterostructure, generated through localized femtosecond photoexcitation of the GaAs. Transient structural changes in both the substrate and film are measured with picosecond time-resolved x-ray diffraction. The data indicate an elastic response consisting of unipolar compression pulses of a few hundred picosecond duration traveling along [001] and [001] directions that are produced by predominately impulsive stress. The transmission and reflection of the strain pulses are in agreement with an acoustic mismatch model of the heterostructure and free-space interfaces.

  11. Generation of high-photon flux-coherent soft x-ray radiation with few-cycle pulses.

    PubMed

    Demmler, Stefan; Rothhardt, Jan; Hädrich, Steffen; Krebs, Manuel; Hage, Arvid; Limpert, Jens; Tünnermann, Andreas

    2013-12-01

    We present a tabletop source of coherent soft x-ray radiation with high-photon flux. Two-cycle pulses delivered by a fiber-laser-pumped optical parametric chirped-pulse amplifier operating at 180 kHz repetition rate are upconverted via high harmonic generation in neon to photon energies beyond 200 eV. A maximum photon flux of 1.3·10(8) photons/s is achieved within a 1% bandwidth at 125 eV photon energy. This corresponds to a conversion efficiency of ~10(-9), which can be reached due to a gas jet simultaneously providing a high target density and phase matching. Further scaling potential toward higher photon flux as well as higher photon energies are discussed. PMID:24281507

  12. Compact x-ray source and panel

    DOEpatents

    Sampayon, Stephen E.

    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.

  13. Modular approach to achieving the next-generation X-ray light source

    NASA Astrophysics Data System (ADS)

    Biedron, S. G.; Milton, S. V.; Freund, H. P.

    2001-12-01

    A modular approach to the next-generation light source is described. The "modules" include photocathode, radio-frequency, electron guns and their associated drive-laser systems, linear accelerators, bunch-compression systems, seed laser systems, planar undulators, two-undulator harmonic generation schemes, high-gain harmonic generation systems, nonlinear higher harmonics, and wavelength shifting. These modules will be helpful in distributing the next-generation light source to many more laboratories than the current single-pass, high-gain free-electron laser designs permit, due to both monetary and/or physical space constraints.

  14. X-Rays

    MedlinePlus

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

  15. Cosmic x ray physics

    NASA Technical Reports Server (NTRS)

    Mccammon, Dan; Cox, D. P.; Kraushaar, W. L.; Sanders, W. T.

    1990-01-01

    The annual progress report on Cosmic X Ray Physics is presented. Topics studied include: the soft x ray background, proportional counter and filter calibrations, the new sounding rocket payload: X Ray Calorimeter, and theoretical studies.

  16. Cosmic x ray physics

    NASA Technical Reports Server (NTRS)

    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.

  17. Joint x-ray

    MedlinePlus

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

  18. Organic semiconducting single crystals as next generation of low-cost, room-temperature electrical X-ray detectors.

    PubMed

    Fraboni, Beatrice; Ciavatti, Andrea; Merlo, Francesco; Pasquini, Luca; Cavallini, Anna; Quaranta, Alberto; Bonfiglio, Annalisa; Fraleoni-Morgera, Alessandro

    2012-05-01

    Direct, solid-state X-ray detectors based on organic single crystals are shown to operate at room temperature, in air, and at voltages as low as a few volts, delivering a stable and reproducible linear response to increasing X-ray dose rates, with notable radiation hardness and resistance to aging. All-organic and optically transparent devices are reported. PMID:22451192

  19. Absorbed dose-to-water protocol applied to synchrotron-generated x-rays at very high dose rates.

    PubMed

    Fournier, P; Crosbie, J C; Cornelius, I; Berkvens, P; Donzelli, M; Clavel, A H; Rosenfeld, A B; Petasecca, M; Lerch, M L F; Bräuer-Krisch, E

    2016-07-21

    Microbeam radiation therapy (MRT) is a new radiation treatment modality in the pre-clinical stage of development at the ID17 Biomedical Beamline of the European synchrotron radiation facility (ESRF) in Grenoble, France. MRT exploits the dose volume effect that is made possible through the spatial fractionation of the high dose rate synchrotron-generated x-ray beam into an array of microbeams. As an important step towards the development of a dosimetry protocol for MRT, we have applied the International Atomic Energy Agency's TRS 398 absorbed dose-to-water protocol to the synchrotron x-ray beam in the case of the broad beam irradiation geometry (i.e. prior to spatial fractionation into microbeams). The very high dose rates observed here mean the ion recombination correction factor, k s , is the most challenging to quantify of all the necessary corrections to apply for ionization chamber based absolute dosimetry. In the course of this study, we have developed a new method, the so called 'current ramping' method, to determine k s for the specific irradiation and filtering conditions typically utilized throughout the development of MRT. Using the new approach we deduced an ion recombination correction factor of 1.047 for the maximum ESRF storage ring current (200 mA) under typical beam spectral filtering conditions in MRT. MRT trials are currently underway with veterinary patients at the ESRF that require additional filtering, and we have estimated a correction factor of 1.025 for these filtration conditions for the same ESRF storage ring current. The protocol described herein provides reference dosimetry data for the associated Treatment Planning System utilized in the current veterinary trials and anticipated future human clinical trials. PMID:27366861

  20. Absorbed dose-to-water protocol applied to synchrotron-generated x-rays at very high dose rates

    NASA Astrophysics Data System (ADS)

    Fournier, P.; Crosbie, J. C.; Cornelius, I.; Berkvens, P.; Donzelli, M.; Clavel, A. H.; Rosenfeld, A. B.; Petasecca, M.; Lerch, M. L. F.; Bräuer-Krisch, E.

    2016-07-01

    Microbeam radiation therapy (MRT) is a new radiation treatment modality in the pre-clinical stage of development at the ID17 Biomedical Beamline of the European synchrotron radiation facility (ESRF) in Grenoble, France. MRT exploits the dose volume effect that is made possible through the spatial fractionation of the high dose rate synchrotron-generated x-ray beam into an array of microbeams. As an important step towards the development of a dosimetry protocol for MRT, we have applied the International Atomic Energy Agency’s TRS 398 absorbed dose-to-water protocol to the synchrotron x-ray beam in the case of the broad beam irradiation geometry (i.e. prior to spatial fractionation into microbeams). The very high dose rates observed here mean the ion recombination correction factor, k s , is the most challenging to quantify of all the necessary corrections to apply for ionization chamber based absolute dosimetry. In the course of this study, we have developed a new method, the so called ‘current ramping’ method, to determine k s for the specific irradiation and filtering conditions typically utilized throughout the development of MRT. Using the new approach we deduced an ion recombination correction factor of 1.047 for the maximum ESRF storage ring current (200 mA) under typical beam spectral filtering conditions in MRT. MRT trials are currently underway with veterinary patients at the ESRF that require additional filtering, and we have estimated a correction factor of 1.025 for these filtration conditions for the same ESRF storage ring current. The protocol described herein provides reference dosimetry data for the associated Treatment Planning System utilized in the current veterinary trials and anticipated future human clinical trials.

  1. The PixFEL project: Progress towards a fine pitch X-ray imaging camera for next generation FEL facilities

    NASA Astrophysics Data System (ADS)

    Rizzo, G.; Batignani, G.; Benkechkache, M. A.; Bettarini, S.; Casarosa, G.; Comotti, D.; Dalla Betta, G.-F.; Fabris, L.; Forti, F.; Grassi, M.; Lodola, L.; Malcovati, P.; Manghisoni, M.; Mendicino, R.; Morsani, F.; Paladino, A.; Pancheri, L.; Paoloni, E.; Ratti, L.; Re, V.; Traversi, G.; Vacchi, C.; Verzellesi, G.; Xu, H.

    2016-07-01

    The INFN PixFEL project is developing the fundamental building blocks for a large area X-ray imaging camera to be deployed at next generation free electron laser (FEL) facilities with unprecedented intensity. Improvement in performance beyond the state of art in imaging instrumentation will be explored adopting advanced technologies like active edge sensors, a 65 nm node CMOS process and vertical integration. These are the key ingredients of the PixFEL project to realize a seamless large area focal plane instrument composed by a matrix of multilayer four-side buttable tiles. In order to minimize the dead area and reduce ambiguities in image reconstruction, a fine pitch active edge thick sensor is being optimized to cope with very high intensity photon flux, up to 104 photons per pixel, in the range from 1 to 10 keV. A low noise analog front-end channel with this wide dynamic range and a novel dynamic compression feature, together with a low power 10 bit analog to digital conversion up to 5 MHz, has been realized in a 110 μm pitch with a 65 nm CMOS process. Vertical interconnection of two CMOS tiers will be also explored in the future to build a four-side buttable readout chip with high density memories. In the long run the objective of the PixFEL project is to build a flexible X-ray imaging camera for operation both in burst mode, like at the European X-FEL, or in continuous mode with the high frame rates anticipated for future FEL facilities.

  2. X-Ray Diffraction Apparatus

    NASA Technical Reports Server (NTRS)

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

    1996-01-01

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

  3. Harmonic generation in VUV/x-ray range at the Duke storage ring FEL using electron beam outcoupling

    SciTech Connect

    Litvinenko, V.N.; Burnham, B.; Madey, J.M.J.

    1995-12-31

    We suggest using the OK-4 FEL operating in giant pulse mode to generate intracavity optical power at a level of hundreds of megawatts. These levels of power are sufficient to generate harmonics in the electron beam density. The prebunched electron beam then radiates coherently in an additional wiggler which is tuned on a harmonic of the OK-4 wavelength. The electron beam is turned by an achromatic bend into this wiggler, and harmonic radiation propagates with a small angle with respect to the OK-4 optical axis. This radiation will pass around the mirror of the OK-4 optical cavity and can then be utilized. This electron outcoupling scheme was suggested by N.A. Vinokurov as a method of optics independent outcoupling for high power FELs where electron beam bunching is provided in the master oscillator. This scheme is perfectly suited for optics independent harmonic generation. We suggest to operate the OK-4 FEL as a master oscillator in the UV range of 100 to 250 nm where conventional optics are available. This harmonic generation scheme would allow us to cover the VUV and soft X-Ray range with tunable coherent radiation. In this paper we present the possible layout of this system at the Duke storage ring and its expected operating parameters.

  4. Center for X-Ray Optics, 1986

    SciTech Connect

    Not Available

    1987-07-01

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

  5. X-ray FEL based on harmonics generation and electron beam outcoupling

    SciTech Connect

    Litvinenko, V.N.; Burnham, B.

    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.

  6. Performance of a ruthenium beam separator used to separate soft x rays from light generated by a high-order harmonic light source.

    PubMed

    Ichimaru, Satoshi; Hatayama, Masatoshi; Ohchi, Tadayuki; Gullikson, Eric M; Oku, Satoshi

    2016-02-10

    We describe the design and fabrication of a ruthenium beam separator used to simultaneously attenuate infrared light and reflect soft x rays. Measurements in the infrared and soft x-ray regions showed the beam separator to have a reflectivity of 50%-85% in the wavelength region from 6 to 10 nm at a grazing incidence angle of 7.5 deg and 4.3% at 800 nm and the same angle of grazing incidence, indicating that the amount of attenuation is 0.05-0.09. These results show that this beam separator could provide an effective means for separating IR light from soft x rays in light generated by high-order harmonic generation sources. PMID:26906363

  7. 2.5 Gbps clock data recovery using 1/4th-rate quadricorrelator frequency detector and skew-calibrated multi-phase clock generator

    NASA Astrophysics Data System (ADS)

    Tontisirin, S.; Tielert, R.

    2006-09-01

    A Gb/s clock and data recovery (CDR) circuit using 1/4th-rate digital quadricorrelator frequency detector and skew-calibrated multi-phase voltage-controlled oscillator is presented. With 1/4th-rate clock architecture, the coil-free oscillator can have lower operation frequency providing sufficient low-jitter operation. Moreover, it is an inherent 1-to-4 DEMUX. The skew calibration scheme is applied to reduce phase offset in multi-phase clock generator. The CDR with frequency detector can have small loop bandwidth, wide pull-in range and can operate without the need for a local reference clock. This 1/4th-rate CDR is implemented in standard 0.18 μm CMOS technology. It has an active area of 0.7 mm2 and consumes 100 mW at 1.8 V supply. The CDR has low jitter operation in a wide frequency range from 1-2.25 Gb/s. Measurement of Bit-Error Rate is less than 10-12 for 2.25 Gb/s incoming data 27-1 PRBS, jitter peak-to-peak of 0.7 unit interval (UI) modulation at 10 MHz.

  8. Chest x-ray

    MedlinePlus

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

  9. A High Efficiency Grazing Incidence Pumped X-ray Laser

    SciTech Connect

    Dunn, J; Keenan, R; Price, D F; Patel, P K; Smith, R F; Shlyaptsev, V N

    2006-08-31

    The main objective of the project is to demonstrate a proof-of-principle, new type of high efficiency, short wavelength x-ray laser source that will operate at unprecedented high repetition rates (10Hz) that could be scaled to 1kHz or higher. The development of a high average power, tabletop x-ray laser would serve to complement the wavelength range of 3rd and future 4th generation light sources, e.g. the LCLS, being developed by DOE-Basic Energy Sciences. The latter are large, expensive, central, synchrotron-based facilities while the tabletop x-ray laser is compact, high-power laser-driven, and relatively inexpensive. The demonstration of such a unique, ultra-fast source would allow us to attract funding from DOE-BES, NSF and other agencies to pursue probing of diverse materials undergoing ultrafast changes. Secondly, this capability would have a profound impact on the semiconductor industry since a coherent x-ray laser source would be ideal for ''at wavelength'' {approx}13 nm metrology and microscopy of optics and masks used in EUV lithography. The project has major technical challenges. We will perform grazing-incidence pumped laser-plasma experiments in flat or groove targets which are required to improve the pumping efficiency by ten times. Plasma density characterization using our existing unique picosecond x-ray laser interferometry of laser-irradiated targets is necessary. Simulations of optical laser propagation as well as x-ray laser production and propagation through freely expanding and confined plasma geometries are essential. The research would be conducted using the Physics Directorate Callisto and COMET high power lasers. At the end of the project, we expect to have a high-efficiency x-ray laser scheme operating below 20 nm at 10Hz with a pulse duration of {approx}2 ps. This will represent the state-of-the-art in x-ray lasers and would be a major step forward from our present picosecond laser-driven x-ray lasers. There is an added bonus of creating

  10. Proton- and x-ray beams generated by ultra-fast CO(2) lasers for medical applications

    SciTech Connect

    Pogorelsky, I.; Polyanskiy, M.; Yakimenko, V.; Ben-Zvi, I.; Shkolnikov, P. Najmudin, Z.; Palmer, C.A.J.; Dover, N.P.; Oliva, P; Carpinelli, M.

    2011-07-01

    Recent progress in using picosecond CO{sub 2} 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 CO{sub 2} 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 CO{sub 2} 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 CO{sub 2} laser to sub-PW peak power. This planned improvement includes optimizing the 10-{mu}m ultra-short pulse generation, assuring higher amplification in the CO{sub 2} 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 CO{sub 2} lasers in medicine and other areas.

  11. Proton- and x-ray beams generated by ultra-fast CO2 lasers for medical applications

    NASA Astrophysics Data System (ADS)

    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.

  12. Soft x-ray imaging of intracellular granules of filamentous cyanobacterium generating musty smell in Lake Biwa

    NASA Astrophysics Data System (ADS)

    Takemoto, K.; Mizuta, G.; Yamamoto, A.; Yoshimura, M.; Ichise, S.; Namba, H.; Kihara, H.

    2013-10-01

    A planktonic blue-green algae, which are currently identified as Phormidium tenue, was observed by a soft x-ray microscopy (XM) for comparing a musty smell generating green strain (PTG) and a non-smell brown strain (PTB). By XM, cells were clearly imaged, and several intracellular granules which could not be observed under a light microscope were visualized. The diameter of granules was about 0.5-1 μm, and one or a few granules were seen in a cell. XM analyses showed that width of cells and sizes of intracellular granules were quite different between PTG and PTB strains. To study the granules observed by XM, transmission in more detail, transmission electron microscopy (TEM) and indirect fluorescent-antibody technique (IFA) were applied. By TEM, carboxysomes, thylakoids and polyphosphate granules were observed. IFA showed the presence of carboxysomes. Results lead to the conclusion that intracellular granules observed under XM are carboxysomes or polyphosphate granules. These results demonstrate that soft XM is effective for analyzing fine structures of small organisms such as cyanobacterium, and for discriminating the strains which generates musty smells from others.

  13. Generation of hard x rays from transition radiation using high-density foils and moderate-energy electrons

    SciTech Connect

    Piestrup, M.A. ); Moran, M.J. ); Boyers, D.G.; Pincus, C.I. ); Kephart, J.O. ); Gearhart, R.A. ); Maruyama, X.K. )

    1991-03-01

    In experiments using targets consisting of many thin metal foils, we have demonstrated that a narrow, forward-directed cone of transition radiation in the 8- to 60-keV spectral range can be generated by electron beams with moderate energies (between 100 and 500 MeV). The theory suggests that high-density, moderate-atomic-number metals are the optimum foil materials and that the foil thickness can be chosen to maximize photon production within a desired spectral range. The three targets used in the experiments consisted of 10 foils of 1-{mu}m-thick gold, 40 foils of 8.5-{mu}m stainless steel, and 20 foils of 7.9-{mu}m copper. The efficiency with which hard x rays are generated, and the fact that the requisite electron-beam energies are lower by a factor of 5 to 10, make such a radiation source an attractive alternative to synchrotron radiation for applications such as medical imaging, spectroscopy, and microscopy.

  14. Design and characterization of electron beam focusing for X-ray generation in novel medical imaging architecturea

    PubMed Central

    Bogdan Neculaes, V.; Zou, Yun; Zavodszky, Peter; Inzinna, Louis; Zhang, Xi; Conway, Kenneth; Caiafa, Antonio; Frutschy, Kristopher; Waters, William; De Man, Bruno

    2014-01-01

    A novel electron beam focusing scheme for medical X-ray sources is described in this paper. Most vacuum based medical X-ray sources today employ a tungsten filament operated in temperature limited regime, with electrostatic focusing tabs for limited range beam optics. This paper presents the electron beam optics designed for the first distributed X-ray source in the world for Computed Tomography (CT) applications. This distributed source includes 32 electron beamlets in a common vacuum chamber, with 32 circular dispenser cathodes operated in space charge limited regime, where the initial circular beam is transformed into an elliptical beam before being collected at the anode. The electron beam optics designed and validated here are at the heart of the first Inverse Geometry CT system, with potential benefits in terms of improved image quality and dramatic X-ray dose reduction for the patient. PMID:24826066

  15. Design and characterization of electron beam focusing for X-ray generation in novel medical imaging architecturea)

    NASA Astrophysics Data System (ADS)

    Bogdan Neculaes, V.; Zou, Yun; Zavodszky, Peter; Inzinna, Louis; Zhang, Xi; Conway, Kenneth; Caiafa, Antonio; Frutschy, Kristopher; Waters, William; De Man, Bruno

    2014-05-01

    A novel electron beam focusing scheme for medical X-ray sources is described in this paper. Most vacuum based medical X-ray sources today employ a tungsten filament operated in temperature limited regime, with electrostatic focusing tabs for limited range beam optics. This paper presents the electron beam optics designed for the first distributed X-ray source in the world for Computed Tomography (CT) applications. This distributed source includes 32 electron beamlets in a common vacuum chamber, with 32 circular dispenser cathodes operated in space charge limited regime, where the initial circular beam is transformed into an elliptical beam before being collected at the anode. The electron beam optics designed and validated here are at the heart of the first Inverse Geometry CT system, with potential benefits in terms of improved image quality and dramatic X-ray dose reduction for the patient.

  16. Intermediate Results Of The Program On Realization Of High-Power Soft X-ray Radiation Source Powered From Magneto-Cumulative Generators

    SciTech Connect

    Selemir, V.D.; Demidov, V.A.; Ermolovich, V.F.; Spirov, G.M.; Repin, P.B.; Pikulin, I.V.; Volkov, A.A.; Orlov, A.P.; Boriskin, A.S.; Tatsenko, O.M.; Markevtsev, I.M.; Moiseenko, A.N.; Kazakov, S.A.; Selyavsky, V.T.; Shapovalov, E.V.; Giterman, B.P.; Vlasov, Yu.V.; Dydykin, P.S.; Ryaslov, E.A.; Kotelnikov, D.V.

    2006-01-05

    In the paper we discuss experiments on wire liner systems powering from helical and disk magneto-cumulative generators with a current from 2...3 MA up to 20 MA at current rise time from 0.3 {mu}s to 1 {mu}s, respectively. At currents level up to 4 MA maximum yield of soft x-ray radiation was more than 100 kJ at plasma pinch temperature of 55 eV. At currents up to 20 MA an expected yield of soft x-ray radiation exceeds 1 MJ.

  17. Analysis of the photoneutron activation effects generated by 9 MeV X-ray in a container cargo inspection facility.

    PubMed

    Cho, Young Ho; Kang, Bo Sun

    2010-06-01

    The X-ray container cargo inspection facility is extensively implemented with the key objective to counter international terrorism and illicit smuggling of the contraband items via the ports. However, activation products are generated from photoneutron capture reactions in the high-energy X-ray container cargo inspection facility. The activation products release inherent delayed radiations which occupational workers are exposed to. In this study, the activation products are estimated using Monte Carlo method and radiation safety of the facility in terms of occupational dose is reviewed. PMID:20159916

  18. X-Ray Imaging System

    NASA Astrophysics Data System (ADS)

    1986-01-01

    The FluoroScan Imaging System is a high resolution, low radiation device for viewing stationary or moving objects. It resulted from NASA technology developed for x-ray astronomy and Goddard application to a low intensity x-ray imaging scope. FlouroScan Imaging Systems, Inc, (formerly HealthMate, Inc.), a NASA licensee, further refined the FluoroScan System. It is used for examining fractures, placement of catheters, and in veterinary medicine. Its major components include an x-ray generator, scintillator, visible light image intensifier and video display. It is small, light and maneuverable.

  19. X-ray burst sources

    NASA Technical Reports Server (NTRS)

    Lewin, W. H. G.

    1986-01-01

    There are about 100 bright X-ray sources in the Galaxy that are accretion-driven systems composed of a neutron star and a low mass companion that fills its critical Roche lobe. Many of these systems generate recurring X-ray bursts that are the result of thermonuclear flashes in the neutron star's surface layers, and are accompanied by a somewhat delayed optical burst due to X-ray heating of accretion disk. The Rapid Burster discovered in 1976 exhibits an interval between bursts that is strongly correlated with the energy in the preceding burst. There is no optical identification for this object.

  20. The Maria-Goeppert-Mayer Award Lecture: The Science of Ultrashort Pulse Generation, in the Visible and X-Ray Regions of the Spectrum

    NASA Astrophysics Data System (ADS)

    Murnane, Margaret M.

    1997-04-01

    Ultrashort x-ray pulses give researchers a new window through which to view the natural world, with the ability to spatially and temporally resolve processes basic to material and chemical systems. In the 1990's, there has been a revolution in the technology of laser sources, resulting in the ability to simply and reliably produce light pulses as short as 3 optical cycles in duration, both in the visible and the x-ray region of the spectrum. Also, powerful new techniques to obtain accurate pictures of the exact shape of these ultrashort light pulses have been developed, which are revolutionizing the way we think about and use light. Finally, using harmonic techniques to up-convert visible light into the x-ray region, we can generate coherent and tunable light below 5 nm, with unprecedented short duration (3-10 fs).

  1. Efficient Generation of Attosecond X-Ray Radiation under Interaction of Ultrarelativistic Few-Cycle Laser Pulse with a Thin Foil

    SciTech Connect

    Mikhailova, J. M.; Platonenko, V. T.

    2006-04-07

    The possibility of efficient generation of isolated attosecond X-ray pulses in the interaction of a few-cycle laser pulse of ultrarelativistic intensity with a thin solid-density foil has been demonstrated by 1D and 2D PIC simulations.

  2. Atmospheric electron x-ray spectrometer

    NASA Technical Reports Server (NTRS)

    Feldman, Jason E. (Inventor); George, Thomas (Inventor); Wilcox, Jaroslava Z. (Inventor)

    2002-01-01

    The present invention comprises an apparatus for performing in-situ elemental analyses of surfaces. The invention comprises an atmospheric electron x-ray spectrometer with an electron column which generates, accelerates, and focuses electrons in a column which is isolated from ambient pressure by a:thin, electron transparent membrane. After passing through the membrane, the electrons impinge on the sample in atmosphere to generate characteristic x-rays. An x-ray detector, shaping amplifier, and multi-channel analyzer are used for x-ray detection and signal analysis. By comparing the resultant data to known x-ray spectral signatures, the elemental composition of the surface can be determined.

  3. 20-100 keV K(alpha) X-Ray Source Generation by Short Pulse High Intensity Lasers

    SciTech Connect

    Park, H-S; Koch, J A; Landen, O L; Phillips, T W; Goldsack, T

    2003-08-22

    We are studying the feasibility of utilizing K{alpha} x-ray sources in the range of 20 to 100 keV as a backlighters for imaging various stages of implosions and high areal density planar samples driven by the NIF laser facility. The hard x-ray K{alpha} sources are created by relativistic electron plasma interactions in the target material after a radiation by short pulse high intensity lasers. In order to understand K{alpha} source characteristics such as production efficiency and brightness as a function of laser parameters, we have performed experiments using the 10 J, 100 fs JanUSP laser. We utilized single-photon counting spectroscopy and x-ray imaging diagnostics to characterize the K{alpha} source. We find that the K{alpha} conversion efficiency from the laser energy is {approx} 3 x 10{sup -4}.

  4. Direct density measurement of shock-compressed iron using hard x rays generated by a short laser pulse.

    PubMed

    Brambrink, E; Wei, H G; Barbrel, B; Audebert, P; Benuzzi-Mounaix, A; Boehly, T; Endo, T; Gregory, C D; Kimura, T; Kodama, R; Ozaki, N; Park, H-S; Koenig, M

    2009-11-01

    We present the application of short-pulse laser-driven hard x rays (>40 keV) for the direct density measurement of iron compressed by a laser-driven shock. By using an on-shot calibration of the spectral absorption, we are able to obtain line densities with 5%-10% precision, although the x-ray source is not monochromatic. We also discuss possibilities for increasing the precision, which would be an improvement for equation of state measurements. PMID:20365083

  5. Simulation of the generation of the characteristic X-ray emission by hot electrons in a foil

    SciTech Connect

    Kostenko, O F; Andreev, N E

    2013-03-31

    We have developed a model to calculate the yield of the characteristic X-ray radiation from a foil, taking into account the dependence of the average energy and the number of hot electrons on the intensity of the laser pulse, the self-absorption of X-rays and the effect of refluxing of hot electrons. The yield of K{sub {alpha}} radiation from a silver foil is optimised at relativistic intensities. A method is proposed for diagnosing the effect of electron refluxing, which greatly increases the yield of K{sub {alpha}} radiation. (extreme light fields and their applications)

  6. The simulation of hard X-ray generation at ultra-short laser pulse interaction with high-Z targets

    SciTech Connect

    Lykov, V. A.; Chernyakov, V. E.; Chikulaev, A. A.; Kandiev, Ya. Z.; Nikolaev, V. G.

    1997-04-15

    The simulations of fast electrons interaction with matter were performed by using of ERA code. The yield and angular distribution of bremsstrahlung and fluorescence K-{alpha} X-ray radiation calculated by PRIZMA code for experiments on interaction of ultra-short laser pulses with high-Z targets at intensities of 10{sup 15}-10{sup 18} W/cm{sup 2} are presented. Spherical targets with conical hollows and conical targets of high-Z matter are proposed for experiments with picosecond lasers to increase the brightness of hard X-ray source.

  7. Three-dimensional x-ray microtomography

    SciTech Connect

    Flannery, B.P.; Deckman, H.W.; Roberge, W.G.; D'Amico, K.L.

    1987-09-18

    The new technique of x-ray microtomography nondestructively generates three-dimensional maps of the x-ray attenuation coefficient inside small samples with approximately 1 percent accuracy and with resolution approaching 1 micrometer. Spatially resolved elemental maps can be produced with synchrotron x-ray sources by scanning samples at energies just above and below characteristic atomic absorption edges. The system consists of a high-resolution imaging x-ray detector and high-speed algorithms for tomographic image reconstruction. The design and operation of the microtomography device are described, and tomographic images that illustrate it performance with both synchrotron and laboratory x-ray sources are presented.

  8. Comets: mechanisms of x-ray activity

    NASA Astrophysics Data System (ADS)

    Ibadov, Subhon

    2016-07-01

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

  9. Tunable coherent soft X-ray source based on the generation of high-order harmonic of femtosecond laser radiation in gas-filled capillaries

    SciTech Connect

    Malkov, Yu A; Yashunin, D A; Kiselev, A M; Stepanov, A N; Andreev, N E

    2014-05-30

    We have carried out experimental and theoretical investigations of a tunable coherent soft X-ray radiation source in the 30 – 52 nm wavelength range based on the generation of high-order harmonics of femtosecond laser radiation propagating in a dielectric xenon-filled capillary. The long path of laser pulse propagation through the capillary permits tuning the generated harmonic wavelengths to almost completely span the range under consideration. (interaction of radiation with matter)

  10. Dental x-rays

    MedlinePlus

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

  11. X-ray (image)

    MedlinePlus

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

  12. X Ray Topography

    ERIC Educational Resources Information Center

    Balchin, A. A.

    1974-01-01

    Discusses some aspects in X-ray topography, including formation of dislocations, characteristics of stacking faults, x-ray contrast in defect inspection, Berg-Barrett technique, and Lang traversing crystal and Borrmann's methods. (CC)

  13. Extremity x-ray

    MedlinePlus

    ... degenerative) Bone tumor Broken bone (fracture) Dislocated bone Osteomyelitis (infection) Other conditions for which the test may ... Bone tumor Bone x-ray Broken bone Clubfoot Osteomyelitis X-ray Update Date 10/22/2014 Updated ...

  14. Efficient 2(nd) and 4(th) harmonic generation of a single-frequency, continuous-wave fiber amplifier.

    PubMed

    Sudmeyer, Thomas; Imai, Yutaka; Masuda, Hisashi; Eguchi, Naoya; Saito, Masaki; Kubota, Shigeo

    2008-02-01

    We demonstrate efficient cavity-enhanced second and fourth harmonic generation of an air-cooled, continuous-wave (cw), single-frequency 1064 nm fiber-amplifier system. The second harmonic generator achieves up to 88% total external conversion efficiency, generating more than 20-W power at 532 nm wavelength in a diffraction-limited beam (M(2) < 1.05). The nonlinear medium is a critically phase-matched, 20-mm long, anti-reflection (AR) coated LBO crystal operated at 25 degrees C. The fourth harmonic generator is based on an AR-coated, Czochralski-grown beta-BaB(2)O(4) (BBO) crystal optimized for low loss and high damage threshold. Up to 12.2 W of 266-nm deep-UV (DUV) output is obtained using a 6-mm long critically phase-matched BBO operated at 40 degrees C. This power level is more than two times higher than previously reported for cw 266-nm generation. The total external conversion efficiency from the fundamental at 1064 nm to the fourth harmonic at 266 nm is >50%. PMID:18542230

  15. X-Ray Imaging

    MedlinePlus

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

  16. X-Rays

    MedlinePlus

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

  17. Hand x-ray

    MedlinePlus

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

  18. Sinus x-ray

    MedlinePlus

    Paranasal sinus radiography; X-ray - sinuses ... sinus x-ray is taken in a hospital radiology department. Or the x-ray may be taken ... Brown J, Rout J. ENT, neck, and dental radiology. In: Adam A, Dixon AK, Gillard JH Schaefer- ...

  19. X-pinch source of subnanosecond soft X-ray pulses based on small-sized low-inductance current generator

    SciTech Connect

    Mesyats, G. A.; Shelkovenko, T. A.; Ivanenkov, G. V.; Agafonov, A. V.; Savinov, S. Yu.; Pikuz, S. A.; Tilikin, I. N.; Tkachenko, S. I.; Chaikovskii, S. A.; Ratakhin, N. A.; Fedushchak, V. F.; Oreshkin, V. I.; Fedyunin, A. V.; Russkikh, A. G.; Labetskaya, N. A.; Artemov, A. P.; Hammer, D. A.; Sinars, D. B.

    2010-09-15

    For the first time, the regime of a micrometer-size hot spot formation is impemented for an X-pinch in a plasma, which is fed from a current generator based on low-inductance capacitors and rapid current switches. The configurations of X-pinches, which can be used effectively as point sources of soft X-rays with this type of current generator, are determined. A prototype of a small-size radiation source for high-resolution point projection X-ray radiography has been constructed. The main parameters of X-pinch as a radiation source are analyzed and compared with X-pinch parameters in high-voltage setups with shaping lines. An analysis of the data on the operation of X-pinches in generators with different parameters has led to simple relations that can be used to select optimal initial X-pinch parameters.

  20. A major step in understanding the X-ray generation in comets: recent progress obtained with XMM-Newton

    NASA Astrophysics Data System (ADS)

    Dennerl, Konrad; Aschenbach, Bernd; Burwitz, Vadim; Englhauser, Jakob; Lisse, Casey M.; Rodriguez-Pascual, Pedro M.

    2003-03-01

    The observation of comet C/2000 WM1 (LINEAR) with XMM-Newton is a highlight in the field of cometary research. During 17 hours of almost uninterrupted observations, more than one million photons were recorded with unprecedented spectral resolution. The results obtained so far clearly demonstrate that the X-ray emission is caused by charge exchange reactions between highly charged heavy ions in the solar wind - mainly oxygen and carbon - and cometary gas. Due to the high number of detected photons, an investigation of the X-ray morphology is also possible in considerable detail. The observation was also a highlight from the technological point of view, demonstrating that XMM-Newton has more capabilities than are currently utilized. In order to follow the comet, the orientation of the satellite had to be adjusted several times. This was done by just changing the guide star offsets, leaving the X-ray instruments switched on. Compared to the usual procedure with regular slews, where the X-ray instruments are reinitialized afterwards, this new technique increased the time available for scientific observations by 34% for MOS and by 83% for PN. The capability of performing quick attitude adjustments during an observation may be of interest also for other astrophysical applications.

  1. Multi-mJ mid-infrared kHz OPCPA and Yb-doped pump lasers for tabletop coherent soft x-ray generation

    NASA Astrophysics Data System (ADS)

    Lai, Chien-Jen; Hong, Kyung-Han; Siqueira, Jonathas P.; Krogen, Peter; Chang, Chun-Lin; Stein, Gregory J.; Liang, Houkun; Keathley, Phillip D.; Laurent, Guillaume; Moses, Jeffrey; Zapata, Luis E.; Kärtner, Franz X.

    2015-09-01

    We present our recent progress on the development of a mid-infrared (mid-IR), multi-mJ, kHz optical parametric chirped-pulse amplification (OPCPA) system, pumped by a homebuilt picosecond cryogenic Yb:YAG chirped-pulse amplifier, and its application to soft x-ray high-order harmonic generation. The cryogenic Yb:YAG laser operating at 1 kHz repetition rate delivers 42 mJ, 17 ps, 1.03 μm pulses to pump the OPCPA system. Efficient second and fourth harmonic generations from the Yb:YAG system are demonstrated, which provide the pumping capability for OPCPA at various wavelengths. The mid-IR OPCPA system produces 2.6 mJ, 39 fs, 2.1 μm pulses with good beam quality (M 2 = ∼1.5) at 1 kHz repetition rate. The output pulses of the OPCPA are used to generate high-order harmonics in both gas cell and hollow-core fiber targets. A photon flux of ∼2 × 108 photon/s/1% bandwidth at 160 eV in Ar is measured while the cutoff is 190 eV. The direct measurements of the photon flux from x-ray photodiodes have confirmed the generation of water-window soft x-ray photons with a flux ∼106 photon/s/1% bandwidth at 330 eV in Ne. The demonstrated OPCPA and Yb:YAG pump laser technologies provide an excellent platform of energy and power scalable few-cycle mid-IR sources that are suitable for high-flux tabletop coherent soft x-ray generation.

  2. Generation of Bright, Spatially Coherent Soft X-Ray High Harmonics in a Hollow Waveguide Using Two-Color Synthesized Laser Pulses.

    PubMed

    Jin, Cheng; Stein, Gregory J; Hong, Kyung-Han; Lin, C D

    2015-07-24

    We investigate the efficient generation of low-divergence high-order harmonics driven by waveform-optimized laser pulses in a gas-filled hollow waveguide. The drive waveform is obtained by synthesizing two-color laser pulses, optimized such that highest harmonic yields are emitted from each atom. Optimization of the gas pressure and waveguide configuration has enabled us to produce bright and spatially coherent harmonics extending from the extreme ultraviolet to soft x rays. Our study on the interplay among waveguide mode, atomic dispersion, and plasma effect uncovers how dynamic phase matching is accomplished and how an optimized waveform is maintained when optimal waveguide parameters (radius and length) and gas pressure are identified. Our analysis should help laboratory development in the generation of high-flux bright coherent soft x rays as tabletop light sources for applications. PMID:26252685

  3. Generation of Bright, Spatially Coherent Soft X-Ray High Harmonics in a Hollow Waveguide Using Two-Color Synthesized Laser Pulses

    NASA Astrophysics Data System (ADS)

    Jin, Cheng; Stein, Gregory J.; Hong, Kyung-Han; Lin, C. D.

    2015-07-01

    We investigate the efficient generation of low-divergence high-order harmonics driven by waveform-optimized laser pulses in a gas-filled hollow waveguide. The drive waveform is obtained by synthesizing two-color laser pulses, optimized such that highest harmonic yields are emitted from each atom. Optimization of the gas pressure and waveguide configuration has enabled us to produce bright and spatially coherent harmonics extending from the extreme ultraviolet to soft x rays. Our study on the interplay among waveguide mode, atomic dispersion, and plasma effect uncovers how dynamic phase matching is accomplished and how an optimized waveform is maintained when optimal waveguide parameters (radius and length) and gas pressure are identified. Our analysis should help laboratory development in the generation of high-flux bright coherent soft x rays as tabletop light sources for applications.

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

    DOEpatents

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

    2016-08-09

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

  5. X-ray generation by fast electrons propagating in nanofibres irradiated by a laser pulse of relativistic intensity

    NASA Astrophysics Data System (ADS)

    Andreev, A. A.; Platonov, K. Yu

    2016-02-01

    Numerical simulations were made of the interaction of a relativistically intense laser pulse with a target consisting of nanometre fibres. Fast electrons were shown to execute forced betatron oscillations in the electrostatic fibre field and the laser field. The fibre diameter was determined whereby the amplitude of betatron electron oscillations is resonantly increased. The power of coherent X-ray betatron radiation of the electron bunch was calculated outside of the resonance domain and in the resonance case. We showed that the laser-to-X-ray betatron radiation conversion coefficient in the resonance case amounts to a few percent and the target made up of nanometre fibres may be regarded as an efficient laser-driven source of coherent X- and gamma-ray radiation.

  6. Gas dynamics and heat transfer in a packed pebble-bed reactor for the 4th generation nuclear energy

    NASA Astrophysics Data System (ADS)

    Abdulmohsin, Rahman

    -AlOx-Al junctions, we show that, despite excellent temperature stability, temperature fluctuations induce observable critical current fluctuations. Particularly, becuase 1/ f critical current noise has decreased with improved fabrication techniques in recent years, it is important to understand and eliminate this additional noise source. Next, we introduce a numerical method of calculating the mean square flux noise F2 from independently fluctuating spins on the surface of thin-film loops of arbitrary geometry. By reciprocity, F2 is proportional to Br2 , where B(r) is the magnetic field generated by a circulating current around the loop and r varies over the loop surface. By discretizing the loop nonuniformly, we efficiently and accurately compute the current distribution and resulting magnetic field, which may vary rapidly across the loop. We use this method to compute F2 in a number of scenarios in which we systematically vary physical parameters of the loop. We compare our simulations to an earlier analytic result predicting that F2 ∝ R/W in the limit where the loop radius R is much greater than the linewidth W. We further show that the previously neglected contribution of edge spins to F2 is significant---even dominant---in narrow-linewidth loops. To calculate theoretical dephasing rates in qubits, we consider flux noise with a spectral density Sphi( f) = A2/ (f/1 Hz) alpha, where A is of the order of 1 muphi 0 Hz--1/2 and 0.6 ≤ alpha ≤ 1.2; applied flux, our calculations of the dependence of the pure dephasing time tau φ Ramsey and echo pulse sequences on alpha for fixed A show that tauφ decreases rapidly as alpha is reduced. We find that tauφ is relatively insensitive to the noise bandwidth, f1 ≤ f ≤ f2 for all alpha provided the ultraviolet cutoff frequency f2 > 1/tauφ. We calculate the ratio tauφ,E/tau φ, R of the echo (E) and Ramsey (R) sequences, and the dependence of the decay function on alpha and f2. We investigate the case in which S phi(f0) is fixed

  7. Investigation of characteristics of hard x-rays produced during implosions of wire array loads on 1.6 MA Zebra generator

    NASA Astrophysics Data System (ADS)

    Shrestha, I.; Kantsyrev, V. L.; Safronova, A. S.; Esaulov, A. A.; Williamson, K. M.; Ouart, N. D.; Osborne, G. C.; Weller, M. E.; Yilmaz, M. F.

    2010-01-01

    Experimental study of the characteristics of hard x-ray (HXR) emission from multi-planar wire arrays and compact-cylindrical wire arrays (CCWA) plasmas on the 1.6 MA Zebra generator at UNR has been carried out. The characteristics of HXR produced by multi-planar wire arrays such as single, double, and triple planar as well as compact-cylindrical wire arrays made from Al, Cu, brass, Mo, and W were analyzed. Data from spatially resolved time-integrated and spatially integrated time-gated x-ray spectra recorded by LiF spectrometers, x-ray pinhole images, and signals from fast x-ray detectors have been used to study spatial distribution and time history of HXR emission with different loads. The dependence of the HXR yield and power on the wire material, geometry of the load and load mass is observed. Both HXR yield and power are minimum for Al and maximum for W loads. The HXR yield increases with the rise of the atomic number of the material for all loads. The presence of aluminum wires in the load with the main material such as Cu, Mo, or W in combined wire arrays decreases HXR yield. For W plasma, the intensity of cold L-shell spectral lines (1-1.5 Å) correlates with corresponding amplitude of HXR signals which may suggest the evidence of generation of electron beams in plasma. It is found that HXRs are generated from different plasma regions by the interaction of electron-beam with the plasma trailing mass, with the material of anode and due to thermal radiation from plasma bright spots. The theoretical assumption of thermal mechanism of HXR emission predicts the different trends for dependency of HXR power on atomic number and load mass.

  8. Reflection soft X-ray microscope and method

    DOEpatents

    Suckewer, Szymon; Skinner, Charles H.; Rosser, Roy

    1993-01-01

    A reflection soft X-ray microscope is provided by generating soft X-ray beams, condensing the X-ray beams to strike a surface of an object at a predetermined angle, and focusing the X-ray beams reflected from the surface onto a detector, for recording an image of the surface or near surface features of the object under observation.

  9. Reflection soft X-ray microscope and method

    DOEpatents

    Suckewer, S.; Skinner, C.H.; Rosser, R.

    1993-01-05

    A reflection soft X-ray microscope is provided by generating soft X-ray beams, condensing the X-ray beams to strike a surface of an object at a predetermined angle, and focusing the X-ray beams reflected from the surface onto a detector, for recording an image of the surface or near surface features of the object under observation.

  10. Detailed model for hot-dense aluminum plasmas generated by an x-ray free electron laser

    NASA Astrophysics Data System (ADS)

    Ciricosta, O.; Vinko, S. M.; Chung, H.-K.; Jackson, C.; Lee, R. W.; Preston, T. R.; Rackstraw, D. S.; Wark, J. S.

    2016-02-01

    The possibility of creating hot-dense plasma samples by isochoric heating of solid targets with high-intensity femtosecond X-ray lasers has opened up new opportunities in the experimental study of such systems. A study of the X-ray spectra emitted from solid density plasmas has provided significant insight into the X-ray absorption mechanisms, subsequent target heating, and the conditions of temperature, electron density, and ionization stages produced (Vinko et al., Nature 482, 59-62 (2012)). Furthermore, detailed analysis of the spectra has provided new information on the degree of ionization potential depression in these strongly coupled plasmas (Ciricosta et al., Phys. Rev. Lett. 109, 065002 (2012)). Excellent agreement between experimental and simulated spectra has been obtained, but a full outline of the procedure by which this has been achieved has yet to be documented. We present here the details and approximations concerning the modelling of the experiment described in the above referenced work. We show that it is crucial to take into account the spatial and temporal gradients in simulating the overall emission spectra, and discuss how aspects of the model used affect the interpretation of the data in terms of charge-resolved measurements of the ionization potential depression.

  11. Method of Generating X-Ray Diffraction Data for Integral Detection of Twin Defects in Super-Hetero-Epitaxial Materials

    NASA Technical Reports Server (NTRS)

    Park, Yeonjoon (Inventor); Choi, Sang Hyouk (Inventor); King, Glen C. (Inventor); Elliott, James R. (Inventor)

    2009-01-01

    A method provides X-ray diffraction (XRD) data suitable for integral detection of a twin defect in a strained or lattice-matched epitaxial material made from components having crystal structures having symme try belonging to different space groups. The material is mounted in a n X-ray diffraction (XRD) system. In one embodiment, the XRD system's goniometer angle Omega is set equal to (Theta(sub B)-Beta) where The ta(sub B) is a Bragg angle for a designated crystal plane of the allo y that is disposed at a non-perpendicular orientation with respect to the {111) crystal plane, and Beta is the angle between the designate d crystal plane and a { 111 } crystal plane of one of the epitaxial components. The XRD system's detector angle is set equal to (Theta(su b B)+Beta). The material can be rotated through an angle of azimuthal rotation Phi about the axis aligned with the material. Using the det ector, the intensity of the X-ray diffraction is recorded at least at the angle at which the twin defect occurs.

  12. Panoramic Dental X-Ray

    MedlinePlus

    ... X-ray? What is Panoramic X-ray? Panoramic radiography , also called panoramic x-ray , is a two- ... Exams Dental Cone Beam CT X-ray, Interventional Radiology and Nuclear Medicine Radiation Safety About this Site ...

  13. Dependence of optimal initial density on laser parameters for multi-keV x-ray radiators generated by nanosecond laser-produced underdense plasma

    NASA Astrophysics Data System (ADS)

    Tu, Shao-yong; Yuan, Yong-teng; Hu, Guang-yue; Miao, Wen-yong; Zhao, Bin; Zheng, Jian; Jiang, Shao-en; Ding, Yong-kun

    2016-01-01

    Efficient multi-keV x-ray sources can be produced using nanosecond laser pulse-heated middle-Z underdense plasmas generated using gas or foam. Previous experimental results show that an optimal initial target density exists for efficient multi-keV x-ray emission at which the laser ionization wave is supersonic. Here we explore the influence of the laser intensity and the pulse duration on this optimal initial target density via a one-dimensional radiation hydrodynamic simulation. The simulation shows that the optimal initial density is sensitive to both the laser intensity and the pulse duration. However, the speed of the supersonic ionization wave at the end of the laser irradiation is always maintained at 1.5 to 1.7 times that of the ion acoustic wave under the optimal initial density conditions.

  14. X-ray photoelectron and optical absorption spectroscopic studies on the dye chlorodiane blue, used as a carrier generation molecule in organic photoconductors

    SciTech Connect

    Pacansky, J.; Waltman, R.J.

    1992-07-01

    The dye chlorodiane blue, used as a carrier generation molecule in organic photoconductors, is characterized via optical absorption and X-ray photoelectron spectroscopy, and the results are interpreted on the basis of ab initio quantum mechanical molecular models. These data indicate that chlorodiane blue exists as azo-enol and hydrazone-quinone chemical structures and it is the hydrazone-quinone form that provides the higher xerographic gain in electrophotographic applications. Optimized geometries, atomic charges, and molecular orbital plots and energies are reported for both the azo-enol and hydrazone-quinone forms of chlorodiane blue. The two structural forms of the dye are experimentally distinguishable via both optical absorption and X-ray photoelectron spectroscopy, and the wavelength and chemical shifts, respectively, are interpreted via the theoretical results. 29 refs., 9 figs., 4 tabs.

  15. The study of hard x-ray emission and electron beam generation in wire array Z-pinch and X-pinch plasmas at university-scale generators

    NASA Astrophysics Data System (ADS)

    Shrestha, Ishor Kumar

    The studies of hard x-ray (HXR) emission and electron beam generation in Z-pinch plasmas are very important for Inertial Confinement Fusion (ICF) research and HXR emission application for sources of K-shell and L-shell radiation. Energetic electron beams from Z-pinch plasmas are potentially a problem in the development of ICF. The electron beams and the accompanying HXR emission can preheat the fuel of a thermonuclear target, thereby preventing the fuel compression from reaching densities required for the ignition of a fusion reaction. The photons above 3-4 keV radiated from a Z pinch can provide detailed information about the high energy density plasmas produced at stagnation. Hence, the investigation of characteristics of hard x-rays and electron beams produced during implosions of wire array loads on university scale-generators may provide important data for future ICF, sources of K-shell and L-shell radiations and basic plasma research. This dissertation presents the results of experimental studies of HXR and electron beam generation in wire-array and X-pinch on the 1.7 MA, 100-ns current rise time Zebra generator at University of Nevada, Reno and 1-MA 100-ns current rise-time Cornell Beam Research Accelerator (COBRA) at Cornell University. The experimental study of characteristics of HXR produced by multi-planar wire arrays, compact cylindrical wire array (CCWA) and nested cylindrical wire array (NCWA) made from Al, Cu, Mo, Ag, W and Au were analyzed. The dependence of the HXR yield and power on geometry of the load, the wire material, and load mass was observed. The presence of aluminum wires in the load with the main material such as stainless steel, Cu, Mo, Ag, W or Au in combined wire array decreases HXR yield. The comparison of emission characteristics of HXR and generation of electron beams in CCWA and NCWA on both the high impedance Zebra generator and low impedance COBRA generator were investigated. Some of the "cold" K- shell spectral lines (0.7-2.3

  16. X-ray binaries

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Satellite X-ray experiments and ground-based programs aimed at observation of X-ray binaries are discussed. Experiments aboard OAO-3, OSO-8, Ariel 5, Uhuru, and Skylab are included along with rocket and ground-based observations. Major topics covered are: Her X-1, Cyg X-3, Cen X-3, Cyg X-1, the transient source A0620-00, other possible X-ray binaries, and plans and prospects for future observational programs.

  17. Topological X-Rays and MRIs

    ERIC Educational Resources Information Center

    Lynch, Mark

    2002-01-01

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

  18. X-ray transmissive debris shield

    DOEpatents

    Spielman, Rick B.

    1994-01-01

    A composite window structure is described for transmitting x-ray radiation and for shielding radiation generated debris. In particular, separate layers of different x-ray transmissive materials are laminated together to form a high strength, x-ray transmissive debris shield which is particularly suited for use in high energy fluences. In one embodiment, the composite window comprises alternating layers of beryllium and a thermoset polymer.

  19. Controlling X-rays With Light

    SciTech Connect

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

    2010-08-02

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

  20. Controlling x-rays with light.

    SciTech Connect

    Glover, T. E.; Hertlein, M. P.; Southworth, S. H.; Allison, T. K.; van Tilborg, J.; Kanter, E. P.; Krassig, B.; Varma, H. R.; Rude, B.; Santra, R.; Belkacem, A.; Young, L.; Chemical Sciences and Engineering Division; LBNL; Univ. of California at Berkley; Univ. of Chicago

    2010-01-01

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

  1. A Next-Generation Hard X-Ray Nanoprobe Beamline for In Situ Studies of Energy Materials and Devices

    NASA Astrophysics Data System (ADS)

    Maser, Jörg; Lai, Barry; Buonassisi, Tonio; Cai, Zhonghou; Chen, Si; Finney, Lydia; Gleber, Sophie-Charlotte; Jacobsen, Chris; Preissner, Curt; Roehrig, Chris; Rose, Volker; Shu, Deming; Vine, David; Vogt, Stefan

    2014-01-01

    The Advanced Photon Source is developing a suite of new X-ray beamlines to study materials and devices across many length scales and under real conditions. One of the flagship beamlines of the APS upgrade is the In Situ Nanoprobe (ISN) beamline, which will provide in situ and operando characterization of advanced energy materials and devices under varying temperatures, gas ambients, and applied fields, at previously unavailable spatial resolution and throughput. Examples of materials systems include inorganic and organic photovoltaic systems, advanced battery systems, fuel cell components, nanoelectronic devices, advanced building materials and other scientifically and technologically relevant systems. To characterize these systems at very high spatial resolution and trace sensitivity, the ISN will use both nanofocusing mirrors and diffractive optics to achieve spots sizes as small as 20 nm. Nanofocusing mirrors in Kirkpatrick-Baez geometry will provide several orders of magnitude increase in photon flux at a spatial resolution of 50 nm. Diffractive optics such as zone plates and/or multilayer Laue lenses will provide a highest spatial resolution of 20 nm. Coherent diffraction methods will be used to study even small specimen features with sub-10 nm relevant length scale. A high-throughput data acquisition system will be employed to significantly increase operations efficiency and usability of the instrument. The ISN will provide full spectroscopy capabilities to study the chemical state of most materials in the periodic table, and enable X-ray fluorescence tomography. In situ electrical characterization will enable operando studies of energy and electronic devices such as photovoltaic systems and batteries. We describe the optical concept for the ISN beamline, the technical design, and the approach for enabling a broad variety of in situ studies. We furthermore discuss the application of hard X-ray microscopy to study defects in multi-crystalline solar cells, one

  2. A Next-Generation Hard X-Ray Nanoprobe Beamline for In Situ Studies of Energy Materials and Devices

    SciTech Connect

    Maser, Jong; Lai, Barry; Buonassisi, Toni; Cai, Zhonghou; Chen, Si; Finney, Lydia; Gleber, Sophie-Charlotte; Jacobsen, Chris; Preissner, Curt; Chris Roehrig; Rose, Volker; Shu, Deming; Vine, David; Vogt, Stefan

    2013-08-20

    The Advanced Photon Source is developing a suite of new X-ray beamlines to study materials and devices across many length scales and under real conditions. One of the flagship beamlines of the APS upgrade is the In Situ Nanoprobe (ISN) beamline, which will provide in situ and operando characterization of advanced energy materials and devices under varying temperatures, gas ambients, and applied fields, at previously unavailable spatial resolution and throughput. Examples of materials systems include inorganic and organic photovoltaic systems, advanced battery systems, fuel cell components, nanoelectronic devices, advanced building materials and other scientifically and technologically relevant systems. To characterize these systems at very high spatial resolution and trace sensitivity, the ISN will use both nanofocusing mirrors and diffractive optics to achieve spots sizes as small as 20 nm. Nanofocusing mirrors in Kirkpatrick–Baez geometry will provide several orders of magnitude increase in photon flux at a spatial resolution of 50 nm. Diffractive optics such as zone plates and/or multilayer Laue lenses will provide a highest spatial resolution of 20 nm. Coherent diffraction methods will be used to study even small specimen features with sub-10 nm relevant length scale. A high-throughput data acquisition system will be employed to significantly increase operations efficiency and usability of the instrument. The ISN will provide full spectroscopy capabilities to study the chemical state of most materials in the periodic table, and enable X-ray fluorescence tomography. In situ electrical characterization will enable operando studies of energy and electronic devices such as photovoltaic systems and batteries. We also describe the optical concept for the ISN beamline, the technical design, and the approach for enabling a broad variety of in situ studies. Furthermore, we discuss the application of hard X-ray microscopy to study defects in multi-crystalline solar

  3. Origin of a Raman scattering peak generated in single-walled carbon nanotubes by X-ray irradiation and subsequent thermal annealing

    NASA Astrophysics Data System (ADS)

    Murakami, Toshiya; Matsuda, Mitsuaki; Kisoda, Kenji; Itoh, Chihiro

    2016-08-01

    We have found that a Raman scattering (RS) peak around 1870 cm-1 was produced by the annealing of the X-ray irradiated film of single-walled carbon nanotubes (SWNTs) at 450 oC. The intensity of 1870-cm-1 peak showed a maximum at the probe energy of 2.3 eV for the RS spectroscopy with various probe lasers. Both the peak position and the probe-energy dependence were almost identical to those of the one-dimensional carbon chains previously reported in multi-walled carbon nanotubes. Consequently, we concluded that the 1870-cm-1 peak found in the present study is attributed to carbon chains. The formation of carbon chains by the annealing at temperature lower than 500 oC is firstly reported by the present study. The carbon chains would be formed by aggregation of the interstitial carbons, which are formed as a counterpart of carbon vacancies by X-ray irradiation diffused on SWNT walls. The result indicates that the combination of X-ray irradiation and subsequent thermal annealing is a feasible tool for generating new nanostructures in SWNT.

  4. In vivo crystallography at X-ray free-electron lasers: the next generation of structural biology?

    PubMed

    Gallat, François-Xavier; Matsugaki, Naohiro; Coussens, Nathan P; Yagi, Koichiro J; Boudes, Marion; Higashi, Tetsuya; Tsuji, Daisuke; Tatano, Yutaka; Suzuki, Mamoru; Mizohata, Eiichi; Tono, Kensuke; Joti, Yasumasa; Kameshima, Takashi; Park, Jaehyun; Song, Changyong; Hatsui, Takaki; Yabashi, Makina; Nango, Eriko; Itoh, Kohji; Coulibaly, Fasséli; Tobe, Stephen; Ramaswamy, S; Stay, Barbara; Iwata, So; Chavas, Leonard M G

    2014-07-17

    The serendipitous discovery of the spontaneous growth of protein crystals inside cells has opened the field of crystallography to chemically unmodified samples directly available from their natural environment. On the one hand, through in vivo crystallography, protocols for protein crystal preparation can be highly simplified, although the technique suffers from difficulties in sampling, particularly in the extraction of the crystals from the cells partly due to their small sizes. On the other hand, the extremely intense X-ray pulses emerging from X-ray free-electron laser (XFEL) sources, along with the appearance of serial femtosecond crystallography (SFX) is a milestone for radiation damage-free protein structural studies but requires micrometre-size crystals. The combination of SFX with in vivo crystallography has the potential to boost the applicability of these techniques, eventually bringing the field to the point where in vitro sample manipulations will no longer be required, and direct imaging of the crystals from within the cells will be achievable. To fully appreciate the diverse aspects of sample characterization, handling and analysis, SFX experiments at the Japanese SPring-8 angstrom compact free-electron laser were scheduled on various types of in vivo grown crystals. The first experiments have demonstrated the feasibility of the approach and suggest that future in vivo crystallography applications at XFELs will be another alternative to nano-crystallography. PMID:24914164

  5. Bent crystal X-ray topography

    NASA Technical Reports Server (NTRS)

    Parker, D. L.

    1978-01-01

    A television X-ray topographic camera system was constructed. The system differs from the previous system in that it incorporates the X-ray TV imaging system and has a semi-automatic wafer loading system. Also the X-ray diffraction is in a vertical plane. This feature makes wafer loading easier and makes the system compatible with any commercial X-ray generating system. Topographs and results obtained from a study of the diffraction contrast variation with impurity concentration for both boron implanted and boron diffused silicon are included.

  6. X-ray beamsplitter

    DOEpatents

    Ceglio, Natale M.; Stearns, Daniel S.; Hawryluk, Andrew M.; Barbee, Jr., Troy W.

    1989-01-01

    An x-ray beamsplitter which splits an x-ray beam into two coherent parts by reflecting and transmitting some fraction of an incident beam has applications for x-ray interferometry, x-ray holography, x-ray beam manipulation, and x-ray laser cavity output couplers. The beamsplitter is formed of a wavelength selective multilayer thin film supported by a very thin x-ray transparent membrane. The beamsplitter resonantly transmits and reflects x-rays through thin film interference effects. A thin film is formed of 5-50 pairs of alternate Mo/Si layers with a period of 20-250 A. The support membrane is 10-200 nm of silicon nitride or boron nitride. The multilayer/support membrane structure is formed across a window in a substrate by first forming the structure on a solid substrate and then forming a window in the substrate to leave a free-standing structure over the window.

  7. X-ray beamsplitter

    DOEpatents

    Ceglio, N.M.; Stearns, D.G.; Hawryluk, A.M.; Barbee, T.W. Jr.

    1987-08-07

    An x-ray beamsplitter which splits an x-ray beam into two coherent parts by reflecting and transmitting some fraction of an incident beam has applications for x-ray interferometry, x-ray holography, x-ray beam manipulation, and x-ray laser cavity output couplers. The beamsplitter is formed of a wavelength selective multilayer thin film supported by a very thin x-ray transparent membrane. The beamsplitter resonantly transmits and reflects x-rays through thin film interference effects. A thin film is formed of 5--50 pairs of alternate Mo/Si layers with a period of 20--250 A. The support membrane is 10--200 nm of silicon nitride or boron nitride. The multilayer/support membrane structure is formed across a window in a substrate by first forming the structure on a solid substrate and then forming a window in the substrate to leave a free-standing structure over the window. 6 figs.

  8. X-ray - skeleton

    MedlinePlus

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

  9. Extremity x-ray

    MedlinePlus

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

  10. X-ray Spectrometry.

    ERIC Educational Resources Information Center

    Markowicz, Andrzej A.; Van Grieken, Rene E.

    1984-01-01

    Provided is a selective literature survey of X-ray spectrometry from late 1981 to late 1983. Literature examined focuses on: excitation (photon and electron excitation and particle-induced X-ray emission; detection (wavelength-dispersive and energy-dispersive spectrometry); instrumentation and techniques; and on such quantitative analytical…

  11. Microscopic x-ray luminescence computed tomography

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

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

  12. In Situ Investigations of Laser-Generated Ligand-Free Platinum Nanoparticles by X-ray Absorption Spectroscopy: How Does the Immediate Environment Influence the Particle Surface?

    PubMed

    Fischer, Mathias; Hormes, Josef; Marzun, Galina; Wagener, Philipp; Hagemann, Ulrich; Barcikowski, Stephan

    2016-09-01

    Pulsed laser ablation in liquid (PLAL) has proven its usefulness as a nanoparticle (NP) synthesis method alternative to traditional chemical reduction methods, where the absence of any molecular ligands or residual reactants makes laser-generated nanoparticles ideal reference materials for charge-transfer experiments. We synthesized additive-free platinum nanoparticles by PLAL and in-situ characterized their interaction with H2O, sodium phosphate buffer, and sodium citrate as well as a TiO2 support by X-ray absorption fine structure (XAFS), i.e., X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS). Differences in the white-line intensity among the colloidal particles in the three liquids indicate that the respective NP-solvent interaction varies in strength. The ions added ex situ diffuse through the particles' electric double layer and interact electrostatically with the Stern plane. Consequently, these ions weaken the interaction of the functional OH groups that are bound to the partially oxidized platinum surfaces and cause their partial reduction. Comparing XAFS spectra of laser-generated Pt NPs in citrate with wet-chemically synthesized ones (both ligand-covered) indicates different types of Pt-O bonds: a Pt(IV)O2 type in the case of wet-chemical NPs and a Pt(II)O type in the case of laser-generated NPs. A comparison of unsupported laser-generated platinum NPs in H2O with TiO2-supported ones shows no white-line intensity differences and also an identical number of Pt-O bonds in both cases. This suggests that in the deposition process at least part of the double-layer coating stays intact and that the ligand-free Pt particle properties are preserved in the TiO2-supported Pt particles, relevant for heterogeneous catalysis. PMID:27489980

  13. X-ray monochromator

    NASA Technical Reports Server (NTRS)

    Hoover, Richard B. (Inventor)

    1992-01-01

    An x-ray monochromator is described, wherin a housing supports a plurality of mirrors forming a plurality of opposed mirror faces in parallel with each other and having thereon multilayer coatings, with each of said pairs of mirror faces being provided with identical coatings which are different from the coatings on the other pairs of mirror faces such that each pair of mirror faces has a peak x-ray reflection at a different wavelength regime. The housing is moveable to bring into a polychromatic x-ray beam that pair of mirror faces having the best x-ray reflection for the desired wavelength, with the mirrors being pivotable to move the mirror faces to that angle of incidence at which the peak reflectivity of the desired wavelength x-rays occurs.

  14. A prototype for computer management of petroleum data and generation of maps and sections using 4th dimension{sup {trademark}}

    SciTech Connect

    French, D.E.; McBane, J.D.

    1996-06-01

    A commercial relational database program available for Macintosh and Windows-based computers known as 4th Dimension, has been adapted for use as a tool for storage, manipulation, and presentation of petroleum industry data. The database organization, input and output layouts, and manipulation routines are collectively referred to as WellFile4. Well data, land-survey data, production statistics, and stratigraphic information can be entered into the database from the keyboard or by importing files purchased from data vendors. The data can then be organized into files that can be searched and sorted based upon user-defined criteria. Selected subsets of data can be printed in various custom report formats. A graphics-editing module, 4D Draw, is used to generate maps, cross sections, and borehole-completion profiles. Maps can incorporate well-header information, formation tops, isopach values, or production data. Production data can also be presented as a bubble map. Maps can also include data selected from tables generated by a spreadsheet module, 4D Calc. Seismic-time values can be treated with appropriate velocity functions using the spreadsheet to derive depth values for posting to the base map. Structural or stratigraphic cross sections can be generated by selecting wells or seismic shot points from a map, and vertical exaggeration can be determined by the user. Maps can be modified extensively by the user before printing or plotting, and can be saved as a document that can be opened by other programs. Production statistics can be compiled based upon location, stratigraphic interval, or other criteria into a single set of data and presented as a chart or table. These can be printed or saved as a text file for use by other spreadsheet or chart-generation programs.

  15. Ultrashort X-ray pulse science

    SciTech Connect

    Chin, Alan Hap

    1998-05-01

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

  16. Generation and characterization of plasma channels in gas puff targets using soft X-ray radiography technique

    NASA Astrophysics Data System (ADS)

    Wachulak, P. W.; Bartnik, A.; Jarocki, R.; Fok, T.; Wegrzyński, Ł.; Kostecki, J.; Szczurek, M.; Jabczyński, J.; Fiedorowicz, H.

    2014-10-01

    We present our recent results of a formation and characterization of plasma channels in elongated krypton and xenon gas puff targets. The study of their formation and temporal expansion was carried out using a combination of a soft X-ray radiography (shadowgraphy) and pinhole camera imaging. Two high-energy short laser pulses were used to produce the channels. When a pumping laser pulse was shaped into a line focus, using cylindrical and spherical lenses, the channels were not produced because much smaller energy density was deposited in the gas puff target. However, when a point focus was obtained, using just a spherical lens, the plasma channels appeared. The channels were up to 9 mm in length, had a quite uniform density profile, and expanded in time with velocities of about 2 cm/μs.

  17. [X-ray interferometry of the axial movement of myosin heads during muscle force generation initiated by T-jump].

    PubMed

    Kubasova, N A; Bershitskiĭ, S Iu; Ferenczi, M A; Panine, P; Narayanan, T; Tsaturian, A K

    2009-01-01

    The interference fine structure of the M3 reflection on the low-angle x-ray diffraction patterns of muscle fibres is used for the measurements of axial movements of myosin heads with a precision of 0.1-0.2 nm. We have measured changes in the M3 interference profile during tension rise induced by a 5 to 30 degrees C temperature jump in thin bundles of contracting fibers from rabbit skeletal muscle. Interpreting the data with a point diffractor model gives an estimate for the axial movement of the myosin heads during force rise of less than 0.6 nm. Modifications of the point diffractor model are discussed. We show that our experimental data can be explained by a model where myosin heads bind actin in a number of structurally different states. PMID:19807033

  18. Planned Use of Pulsed Crab Cavities for Short X-Ray Pulse Generation at the Advanced Photon Source

    SciTech Connect

    Borland, Michael; Carwardine, J.; Chae, Y.; Emery, L.; Den Hartog, Patric; Harkay, K.C.; Lumpkin, A.H.; Nassiri, A.; Sajaev, V.; Sereno, Nicholas S.; Waldschmidt, G.; Yang, B.X.; Dolgashev, V.; /SLAC

    2007-11-06

    Recently, we have explored application to the Advanced Photon Source (APS) of Zholents'[1] crab cavity scheme for production of short x-ray pulses. We assumed use of superconducting (SC) cavities in order to have a continuous stream of crabbed bunches and flexibility of operating modes. The challenges of the SC approach are related to the size, cost, and development time of the cavities and associated systems. A good case can be made [2] for a pulsed system using room-temperature cavities. APS has elected to pursue such a system in the near term, with the SC-based system planned for a later date. This paper describes the motivation for the pulsed system and gives an overview of the planned implementation and issues. Among these are overall configuration options and constraints, cavity design options, frequency choice, cavity design challenges, tolerances, instabilities, and diagnostics plans.

  19. Generation and characterization of plasma channels in gas puff targets using soft X-ray radiography technique

    SciTech Connect

    Wachulak, P. W. Bartnik, A.; Jarocki, R.; Fok, T.; Węgrzyński, Ł.; Kostecki, J.; Szczurek, M.; Jabczyński, J.; Fiedorowicz, H.

    2014-10-15

    We present our recent results of a formation and characterization of plasma channels in elongated krypton and xenon gas puff targets. The study of their formation and temporal expansion was carried out using a combination of a soft X-ray radiography (shadowgraphy) and pinhole camera imaging. Two high-energy short laser pulses were used to produce the channels. When a pumping laser pulse was shaped into a line focus, using cylindrical and spherical lenses, the channels were not produced because much smaller energy density was deposited in the gas puff target. However, when a point focus was obtained, using just a spherical lens, the plasma channels appeared. The channels were up to 9 mm in length, had a quite uniform density profile, and expanded in time with velocities of about 2 cm/μs.

  20. The Wakefield Effects of Pulsed Crab Cavities at the Advanced Photon Source for Short-X-ray Pulse Generation

    SciTech Connect

    Chae, Y.-C.; Waldschmidt, G.; Dolgashev, V.; /SLAC

    2007-11-07

    In recent years we have explored the application to the Advanced Photon Source (APS) of Zholents' crab-cavity based scheme for production of short x-ray pulses. As a near-term project, the APS has elected to pursue a pulsed system using room-temperature cavities. The cavity design has been optimized to heavily damp parasitic modes while maintaining large shunt impedance for the deflecting dipole mode. We evaluated a system consisting of three crab cavities as an impedance source and determined their effect on the single- and multi-bunch instabilities. In the single-bunch instability we used the APS impedance model as the reference system in order to predict the overall performance of the ring when the crab cavities are installed in the future. For multi-bunch instabilities we used a realistic fill pattern, including hybrid-fill, and tracked multiple bunches where each bunch was treated as soft in distribution.

  1. Superconducting Multi-Cell Deflecting Cavity for Short-Pulse X-Ray Generation at the Advanced Photon Source

    SciTech Connect

    G.J. Waldschmidt, L.H. Morrison, R. Nassiri, R.A. Rimmer, K. Tian, H. Wang

    2009-05-01

    A superconducting multi-cell cavity for the production of short x-ray pulses at the Advanced Photon Source (APS) has been explored as an alternative to a single-cell cavity design in order to improve the packing factor and potentially reduce the number of high-power RF systems and low-level RF controls required. The cavity will operate at 2815 MHz in the APS storage ring and will require heavy damping of parasitic modes to maintain stable beam operation. Novel on-cell dampers, attached directly to the cavity body, have been utilized by taking advantage of the magnetic field null on the equatorial plane in order to enhance damping. Design issues and simulation results will be discussed.

  2. Lumbosacral spine x-ray

    MedlinePlus

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

  3. Thoracic spine x-ray

    MedlinePlus

    Vertebral radiography; X-ray - spine; Thoracic x-ray; Spine x-ray; Thoracic spine films; Back films ... The test is done in a hospital radiology department or in the health care provider's office. You will lie on the x-ray table in different positions. If the x-ray ...

  4. X-ray laser

    DOEpatents

    Nilsen, Joseph

    1991-01-01

    An X-ray laser (10) that lases between the K edges of carbon and oxygen, i.e. between 44 and 23 Angstroms, is provided. The laser comprises a silicon (12) and dysprosium (14) foil combination (16) that is driven by two beams (18, 20) of intense line focused (22, 24) optical laser radiation. Ground state nickel-like dysprosium ions (34) are resonantly photo-pumped to their upper X-ray laser state by line emission from hydrogen-like silicon ions (32). The novel X-ray laser should prove especially useful for the microscopy of biological specimens.

  5. X-rays from intermediate mass stars

    NASA Astrophysics Data System (ADS)

    Robrade, Jan

    I will review the X-ray properties of intermediate mass stars and discuss possible X-ray generating mechanisms. Main-sequence stars of spectral type mid B to mid A neither drive sufficiently strong winds to produce shock generated X-rays, nor possess an outer convection zone to generate dynamo driven magnetic activity and coronae. Consequently they should be virtually X-ray dark and occasionally detected X-ray emission was usually attributed to undetected low-mass companions. However, in magnetic intermediate mass stars, the Ap/Bp stars, a different X-ray production mechanism may operate. It is termed the magnetically channeled wind-shock model, where the stellar wind from both hemispheres is channelled towards the equatorial plane, collides and forms a rigidly rotating disk around the star. The strong shocks of the nearly head-on wind collision as well as the existence of magnetically confined plasma in a dynamic circumstellar disk can lead to diverse X-ray phenomena. In this sense Ap/Bp stars bridge the 'classical' X-ray regimes of cool and hot stars.

  6. 600 eV falcon-linac thomson x-ray source

    SciTech Connect

    Crane, J K; LeSage, G P; Ditmire, T; Cross, R; Wharton, K; Moffitt, K; Cowan, T E; Hays, G; Tsai, V; Anderson, G; Shuttlesworth, R; Springer, P

    2000-12-15

    The advent of 3rd generation light sources such as the Advanced Light Source (ALS) at LBL, and the Advanced Photon Source at Argonne, have produced a revolution in x-ray probing of dense matter during the past decade. These machines use electron-synchrotrons in conjunction with undulator stages to produce 100 psec x-ray pulses with photon energies of several kiloelectronvolts (keV). The applications for x-ray probing of matter are numerous and diverse with experiments in medicine and biology, semiconductors and materials science, and plasma and solid state physics. In spite of the success of the 3rd generation light sources there is strong motivation to push the capabilities of x-ray probing into new realms, requiring shorter pulses, higher brightness and harder x-rays. A 4th generation light source, the Linac Coherent Light Source (LCLS), is being considered at the Stanford Linear Accelerator [1]. The LCLS will produce multi-kilovolt x-rays of subpicosecond duration that are 10 orders of magnitude brighter than today's 3rd generation light sources.[1] Although the LCLS will provide unprecedented capability for performing time-resolved x-ray probing of ultrafast phenomena at solid densities, this machine will not be completed for many years. In the meantime there is a serious need for an ultrashort-pulse, high-brightness, hard x-ray source that is capable of probing deep into high-Z solid materials to measure dynamic effects that occur on picosecond time scales. Such an instrument would be ideal for probing the effects of shock propagation in solids using Bragg and Laue diffraction. These techniques can be used to look at phase transitions, melting and recrystallization, and the propagation of defects and dislocations well below the surface in solid materials. [2] These types of dynamic phenomena undermine the mechanical properties of metals and are of general interest in solid state physics, materials science, metallurgy, and have specific relevance to stockpile

  7. X-ray Pulse Length Characterization using the Surface Magneto Optic Kerr Effect

    SciTech Connect

    Krejcik, P.; /SLAC

    2006-10-04

    It will be challenging to measure the temporal profile of the hard X-ray SASE beam independently from the electron beam in the LCLS and other 4th generation light sources. A fast interaction mechanism is needed that can be probed by an ultrafast laser pulse in a pump-probe experiment. It is proposed to exploit the rotation in polarization of light reflected from a thin magnetized film, known as the surface magneto optic Kerr effect (SMOKE), to witness the absorption of the x-ray pulse in the thin film. The change in spin orbit coupling induced by the x-ray pulse occurs on the subfemtosecond time scale and changes the polarization of the probe beam. The limitation to the technique lies with the bandwidth of the probe laser pulse and how short the optical pulse can be made. The SMOKE mechanism will be described and the choices of materials for use with 1.5 {angstrom} x-rays. A schematic description of the pump-probe geometry for x-ray diagnosis is also described.

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

    PubMed

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

    2016-02-01

    Resolution in the X-ray structure determination of noncrystalline samples has been limited to several tens of nanometers, because deep X-ray irradiation required for enhanced resolution causes radiation damage to samples. However, theoretical studies predict that the femtosecond (fs) durations of X-ray free-electron laser (XFEL) pulses make it possible to record scattering signals before the initiation of X-ray damage processes; thus, an ultraintense X-ray beam can be used beyond the conventional limit of radiation dose. Here, we verify this scenario by directly observing femtosecond X-ray damage processes in diamond irradiated with extraordinarily intense (∼10(19) W/cm(2)) XFEL pulses. An X-ray pump-probe diffraction scheme was developed in this study; tightly focused double-5-fs XFEL pulses with time separations ranging from sub-fs to 80 fs were used to excite (i.e., pump) the diamond and characterize (i.e., probe) the temporal changes of the crystalline structures through Bragg reflection. It was found that the pump and probe diffraction intensities remain almost constant for shorter time separations of the double pulse, whereas the probe diffraction intensities decreased after 20 fs following pump pulse irradiation due to the X-ray-induced atomic displacement. This result indicates that sub-10-fs XFEL pulses enable conductions of damageless structural determinations and supports the validity of the theoretical predictions of ultraintense X-ray-matter interactions. The X-ray pump-probe scheme demonstrated here would be effective for understanding ultraintense X-ray-matter interactions, which will greatly stimulate advanced XFEL applications, such as atomic structure determination of a single molecule and generation of exotic matters with high energy densities. PMID:26811449

  9. X-rays and magnetism.

    PubMed

    Fischer, Peter; Ohldag, Hendrik

    2015-09-01

    Magnetism is among the most active and attractive areas in modern solid state physics because of intriguing phenomena interesting to fundamental research and a manifold of technological applications. State-of-the-art synthesis of advanced magnetic materials, e.g. in hybrid structures paves the way to new functionalities. To characterize modern magnetic materials and the associated magnetic phenomena, polarized x-rays have emerged as unique probes due to their specific interaction with magnetic materials. A large variety of spectroscopic and microscopic techniques have been developed to quantify in an element, valence and site-sensitive way properties of ferro-, ferri-, and antiferromagnetic systems, such as spin and orbital moments, and to image nanoscale spin textures and their dynamics with sub-ns time and almost 10 nm spatial resolution. The enormous intensity of x-rays and their degree of coherence at next generation x-ray facilities will open the fsec time window to magnetic studies addressing fundamental time scales in magnetism with nanometer spatial resolution. This review will give an introduction into contemporary topics of nanoscale magnetic materials and provide an overview of analytical spectroscopy and microscopy tools based on x-ray dichroism effects. Selected examples of current research will demonstrate the potential and future directions of these techniques. PMID:26288956

  10. Medical X-Rays

    MedlinePlus

    ... Diagnostic X-Ray Equipment Compliance Program Guidance Manual CP 7386.003 Field Compliance Testing of Diagnostic (Medical) ... and Exporting Electronic Products Compliance Program Guidance Manual CP 7386.003 Field Compliance Testing of Diagnostic (Medical) ...

  11. Dental x-rays

    MedlinePlus

    ... or impacted teeth The presence and extent of dental caries (cavities) Bone damage (such as from periodontitis ) Abscessed ... Dental x-rays can reveal dental cavities (tooth decay) before they ... take yearly bitewings for the early development of cavities.

  12. X-ray - skeleton

    MedlinePlus

    ... is used to look for: Fractures or broken bone Cancer that has spread to other areas of the ... 2014:chap 8. Read More Bone tumor Broken bone Cancer Metastasis Osteomyelitis X-ray Update Date 5/9/ ...

  13. X-Ray Diffraction.

    ERIC Educational Resources Information Center

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

    1980-01-01

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

  14. Abdominal x-ray

    MedlinePlus

    An abdominal x-ray is an imaging test to look at organs and structures in the abdomen. Organs include the spleen, stomach, and intestines. When the test is done to look at the bladder and kidney structures, ...

  15. X-Ray Spectrometry.

    ERIC Educational Resources Information Center

    Macdonald, G. L.

    1980-01-01

    Reviews instrumental developments and technique improvements in X-ray spectrometry, grouped into major topic areas of excitation, dispersion and detection, instrumentation and techniques, and quantitative analyses. Cites 162 references. (CS)

  16. Bone x-ray

    MedlinePlus

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

  17. Cosmic x ray physics

    NASA Technical Reports Server (NTRS)

    Mccammon, Dan; Cox, D. P.; Kraushaar, W. L.; Sanders, W. T.

    1992-01-01

    This final report covers the period 1 January 1985 - 31 March 1992. It is divided into the following sections: the soft x-ray background; proportional counter and filter calibrations; sounding rocket flight preparations; new sounding rocket payload: x-ray calorimeter; and theoretical studies. Staff, publications, conference proceedings, invited talks, contributed talks, colloquia and seminars, public service lectures, and Ph. D. theses are listed.

  18. Thoracic spine x-ray

    MedlinePlus

    Vertebral radiography; X-ray - spine; Thoracic x-ray; Spine x-ray; Thoracic spine films; Back films ... Gillard JH, Schaefer-Prokop CM, eds. Grainger & Allison's Diagnostic Radiology: A Textbook of Medical Imaging . 6th ed. New ...

  19. Heterojunction of Zinc Blende/Wurtzite in Zn1-xCdxS Solid Solution for Efficient Solar Hydrogen Generation: X-ray Absorption/Diffraction Approaches.

    PubMed

    Hsu, Ying-Ya; Suen, Nian-Tzu; Chang, Chung-Chieh; Hung, Sung-Fu; Chen, Chi-Liang; Chan, Ting-Shan; Dong, Chung-Li; Chan, Chih-Chieh; Chen, San-Yuan; Chen, Hao Ming

    2015-10-14

    In the past decade, inorganic semiconductors have been successfully demonstrated as light absorbers in efficient solar water splitting to generate chemical fuels. Pseudobinary semiconductors Zn1-xCdxS (0≤x≤1) have exhibited a superior photocatalytic reactivity of H2 production from splitting of water by artificial solar irradiation without any metal catalysts. However, most studies had revealed that the extremely high efficiency with an optimal content of Zn1-xCdxS solid solution was determined as a result of elevating the conduction band minimum (CBM) and the width of bandgap. In addition to corresponding band structure and bandgap, the local crystal structure should be taken into account as well to determine its photocatalytic performance. Herein, we demonstrated the correlations between the photocatalytic activity and structural properties that were first studied through synchrotron X-ray diffraction and X-ray absorption spectroscopy. The crystal structure transformed from zinc blende to coexisted phases of major zinc blende and minor wurtzite phases at a critical point. The heterojunction formed by coexistence of zinc blende and wurtzite phases in the Zn1-xCdxS solid solution can significantly improve the separation and migration of photoinduced electron-hole pairs. Besides, X-ray absorption spectra and UV-vis spectra revealed that the bandgap of the Zn0.45Cd0.55S sample extended into the region of visible light because of the incorporation of Cd element in the sample. These results provided a significant progress toward the realization of the photoelectrochemical mechanism in heterojunction between zinc blende and wurtzite phases, which can effectively separate the charge-carriers and further suppress their recombination to enhance the photocatalytic reactivity. PMID:26402651

  20. Numerical analysis of experiments on the generation of shock waves in aluminium under indirect (X-ray) action on the Iskra-5 facility

    SciTech Connect

    Bondarenko, S V; Dolgoleva, G V; Novikova, E A

    2013-07-31

    The dynamics of laser and X-ray radiation fields in experiments with cylindrical converter boxes (illuminators), which had earlier been carried out on the Iskra-5 laser facility (the second harmonic of iodine laser radiation, {lambda} = 0.66 {mu}m) was investigated in a sector approximation using the SND-LIRA numerical technique. In these experiments, the X-ray radiation temperature in the box was determined by measuring the velocity of the shock wave generated in the sample under investigation, which was located at the end of the cylindrical illuminator. Through simulations were made using the SND-LIRA code, which took into account the absorption of laser driver radiation at the box walls, the production of quasithermal radiation, as well as the formation and propagation of the shock wave in the sample under investigation. An analysis of the experiments permits determining the electron thermal flux limiter f: for f = 0.03 it is possible to match the experimental scaling data for X-ray in-box radiation temperature to the data of our simulations. The shock velocities obtained from the simulations are also consistent with experimental data. In particular, in the experiment with six laser beams (and a laser energy E{sub L} = 1380 J introduced into the box) the velocity of the shock front (determined from the position of a laser mark) after passage through a 50-{mu}m thick base aluminium layer was equal to 35{+-}1.6 km s{sup -1}, and in simulations to 36 km s{sup -1}. In the experiment with four laser beams (for E{sub L} = 850 J) the shock velocity (measured from the difference of transit times through the base aluminium layer and an additional thin aluminium platelet) was equal to 30{+-}3.6 km s{sup -1}, and in simulations to 30 km s{sup -1}. (interaction of laser radiation with matter)

  1. Z-Pinch Generated X-Rays in Static-Wall Hohlraum Geometry Demonstrate Potential for Indirect-Drive ICF Studies

    SciTech Connect

    BOWERS,RICHARD; CHANDLER,GORDON A.; HEBRON,DAVID E.; LEEPER,RAMON J.; MATUSLKA,WALTER; MOCK,RAYMOND CECIL; NASH,THOMAS J.; OLSON,CRAIG L.; PETERSON,BOB; PETERSON,DARRELL; RUGGLES,LAURENCE E.; SANFORD,THOMAS W. L.; SIMPSON,WALTER W.; STRUVE,KENNETH W.; VESEY,ROGER A.

    1999-11-01

    Hohlraums of full ignition scale (6-mm diameter by 7-mm length) have been heated by x-rays from a z-pinch magnet on Z to a variety of temperatures and pulse shapes which can be used to simulate the early phases of the National Ignition Facility (NIF) temperature drive. The pulse shape is varied by changing the on-axis target of the z pinch in a static-wall-hohlraum geometry. A 2-{micro}m-thick walled Cu cylindrical target of 8-mm diameter filled with 10 mg/cm{sup 3} CH, for example, produces foot-pulse conditions of {approx}85 eV for a duration of {approx}10 ns, while a solid cylindrical target of 5-mm diameter and 14-mg/cm{sup 3} CH generates first-step-pulse conditions of {approx}122 eV for a duration of a few ns. Alternatively, reducing the hohlraum size (to 4-mm diameter by 4-mm length) with the latter target has increased the peak temperature to {approx}150 eV, which is characteristic of a second-step-pulse temperature. In general, the temperature T of these x-ray driven hohlraums is in agreement with the Planckian relation T{approx}(P/A){sup 1/4}. P is the measured x-ray input power and A is the surface area of the hohlraum. Fully-integrated 2-D radiation-hydrodynamic simulations of the z pinch and subsequent hohlraum heating show plasma densities within the useful volume of the hohlraums to be on the order of air or less.

  2. Z-Pinch Generated X-Rays in Static-Wall Hohlraum Geometry Demonstrate Potential for Indirect-Drive ICF Studies

    SciTech Connect

    Sandord, T.W.L.; Olson, R.E.; Chandler, G.A.; Hebron, D.E.; Mock, R.C.; Leeper, R.J.; Nash, T.J.; Ruggles, L.E.; Simpson, W.W.; Struve, K.W.; Vesey, R.A.; Bowers, R.L.; Matuska, W.; Peterson, D.L.; Peterson, R.R.

    1999-08-25

    Hohlraums of full ignition scale (6-mm diameter by 7-mm length) have been heated by x-rays from a z-pinch target on Z to a variety of temperatures and pulse shapes which can be used to simulate the early phases of the National Ignition Facility (NIF) temperature drive. The pulse shape is varied by changing the on-axis target of the z pinch in a static-wall-hohlraum geometry. A 2-{micro}m-thick walled Cu cylindrical target of 8-mm diameter filled with 10 mg/cm{sup 3} CH, for example, produces foot-pulse conditions of {minus}85 eV for a duration of {approximately} 10 ns, while a solid cylindrical target of 5-mm diameter and 14-mg/cm{sup 3} CH generates first-step-pulse conditions of {approximately} 122 eV for a duration of a few ns. Alternatively, reducing the hohlraum size (to 4-mm diameter by 4-mm length) with the latter target has increased the peak temperature to {approximately} 150 eV, which is characteristic of a second-step-pulse temperature. In general, the temperature T of these x-ray driven hohlraums is in agreement with the Planckian relation (T-(P/A){sup 1/4}). P is the measured x-ray input power and A is the surface area of the hohlraum. Fully-integrated 2-D radiation-hydrodynamic simulations of the z pinch and subsequent hohlraum heating show plasma densities within the useful volume of the hohlraums to be on the order of air or less.

  3. Note: On the generation of sub-300 keV flash-X-rays using rod-pinch diode: an experimental investigation.

    PubMed

    Satyanarayana, N; Rajawat, R K; Basu, Shibaji; Rao, A Durga Prasad; Mittal, K C

    2014-09-01

    Generation of flash X-rays (FXRs) at less than 500 keV is described with emphasis on experimental investigation. The pulser is a Tesla transformer-Water transmission line based pulsed power generator operating in double resonance mode to power a rod-pinch diode. The configuration of aspect ratio reported here falls much below the normally reported ratios for the rod-pinch diode operation. Experimental investigation at such low pulsed voltage has revealed "flowering" of the anode tip and "pitting" of the perspex window. A possible explanation in terms of Lorentz body force is discussed rather than the pinch mechanism generally suggested in literature. The experimental investigation for the FXR generation is corroborated by measuring the radiation dose using CaSO4 (Dy) thermo luminescent dosimeters. PMID:25273793

  4. Note: On the generation of sub-300 keV flash-X-rays using rod-pinch diode: An experimental investigation

    NASA Astrophysics Data System (ADS)

    Satyanarayana, N.; Rajawat, R. K.; Basu, Shibaji; Rao, A. Durga Prasad; Mittal, K. C.

    2014-09-01

    Generation of flash X-rays (FXRs) at less than 500 keV is described with emphasis on experimental investigation. The pulser is a Tesla transformer-Water transmission line based pulsed power generator operating in double resonance mode to power a rod-pinch diode. The configuration of aspect ratio reported here falls much below the normally reported ratios for the rod-pinch diode operation. Experimental investigation at such low pulsed voltage has revealed "flowering" of the anode tip and "pitting" of the perspex window. A possible explanation in terms of Lorentz body force is discussed rather than the pinch mechanism generally suggested in literature. The experimental investigation for the FXR generation is corroborated by measuring the radiation dose using CaSO4 (Dy) thermo luminescent dosimeters.

  5. Note: On the generation of sub-300 keV flash-X-rays using rod-pinch diode: An experimental investigation

    SciTech Connect

    Satyanarayana, N.; Rajawat, R. K.; Basu, Shibaji; Rao, A. Durga Prasad; Mittal, K. C.

    2014-09-15

    Generation of flash X-rays (FXRs) at less than 500 keV is described with emphasis on experimental investigation. The pulser is a Tesla transformer-Water transmission line based pulsed power generator operating in double resonance mode to power a rod-pinch diode. The configuration of aspect ratio reported here falls much below the normally reported ratios for the rod-pinch diode operation. Experimental investigation at such low pulsed voltage has revealed “flowering” of the anode tip and “pitting” of the perspex window. A possible explanation in terms of Lorentz body force is discussed rather than the pinch mechanism generally suggested in literature. The experimental investigation for the FXR generation is corroborated by measuring the radiation dose using CaSO{sub 4} (Dy) thermo luminescent dosimeters.

  6. Cross calibration of AGFA-D7 x-ray film against direct exposure film from 2 to 8.5 keV using laser generated x-rays

    NASA Astrophysics Data System (ADS)

    Kyrala, George A.

    2006-05-01

    Direct exposure film (DEF) is being discontinued. DEF film has been the workhorse in inertial confinement fusion (ICF) research and is used to record x-ray images and spectra. A previous search for a replacement [K. M. Chandler et al., Rev. Sci. Instrum. 76, 113111 (2005)] did not consider AGFA film. We present comparisons using the results of measurements using AGFA-D7 film, XAR, TMG, and Biomax-MS films in the same spectrometer recording a gold spectrum in the 2-4keV range and the iron spectrum in the 5-8.5keV range. AGFA film was found to have some unique properties useful in x-ray spectroscopy and imaging, especially when signal strength is not a concern.

  7. Dynamical coherent illumination for X-ray microscopy at 3rd generation synchrotron radiation sources: First results with X-rays at the Ca-K edge (4 keV)

    NASA Astrophysics Data System (ADS)

    Oestreich, S.; Rostaing, G.; Niemann, B.; Kaulich, B.; Salomé, M.; Susini, J.; Barrett, R.

    2000-05-01

    Dynamical coherent illumination is a way to deal with the illumination problems which emerge from the use of low emittance sources at recent synchrotron radiation sources for a transmission X-ray microscope (TXM). An illumination system, which uses two rotating mirrors to provide dynamical coherent illumination has been realized and tested at the TXM at ESRF's ID 21 Beamline. First results are presented and compared to results obtained with partial coherent illumination.

  8. Accelerator-driven X-ray Sources

    SciTech Connect

    Nguyen, Dinh Cong

    2015-11-09

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

  9. Multicolor, time-gated, soft x-ray pinhole imaging of wire array and gas puff Z pinches on the Z and Saturn pulsed power generators

    SciTech Connect

    Jones, B.; Coverdale, C. A.; Nielsen, D. S.; Jones, M. C.; Deeney, C.; Serrano, J. D.; Nielsen-Weber, L. B.; Meyer, C. J.; Apruzese, J. P.; Clark, R. W.; Coleman, P. L.

    2008-10-15

    A multicolor, time-gated, soft x-ray pinhole imaging instrument is fielded as part of the core diagnostic set on the 25 MA Z machine [M. E. Savage et al., in Proceedings of the Pulsed Power Plasma Sciences Conference (IEEE, New York, 2007), p. 979] for studying intense wire array and gas puff Z-pinch soft x-ray sources. Pinhole images are reflected from a planar multilayer mirror, passing 277 eV photons with <10 eV bandwidth. An adjacent pinhole camera uses filtration alone to view 1-10 keV photons simultaneously. Overlaying these data provides composite images that contain both spectral as well as spatial information, allowing for the study of radiation production in dense Z-pinch plasmas. Cu wire arrays at 20 MA on Z show the implosion of a colder cloud of material onto a hot dense core where K-shell photons are excited. A 528 eV imaging configuration has been developed on the 8 MA Saturn generator [R. B. Spielman et al., and A. I. P. Conf, Proc. 195, 3 (1989)] for imaging a bright Li-like Ar L-shell line. Ar gas puff Z pinches show an intense K-shell emission from a zippering stagnation front with L-shell emission dominating as the plasma cools.

  10. Pelvis x-ray

    MedlinePlus

    ... MD, Thompson SR, eds. DeLee and Drez's Orthopaedic Sports Medicine. 4th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap ... Updated by: C. Benjamin Ma, MD, Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic Surgery, ...

  11. Simulation of ultraviolet- and soft X-ray-pulse generation as a result of cooperative recombination of excitons in diamond nanocrystals embedded in a polymer film

    SciTech Connect

    Kukushkin, V. A.

    2013-11-15

    Using numerical simulation, it is shown that the recombination of free excitons photoexcited in diamond nanocrystals embedded in a polymer film can occur in the cooperative mode. It is found that this mode can be implemented despite the fact that diamond is an 'indirect' semiconductor. It is shown that the power of the generated radiation at the pulse peak during the cooperative recombination of free excitons can exceed that of the incoherent spontaneous emission of the same initial number of free excitons by more than an order of magnitude. Finally, it is shown that the process under consideration can be used to generate picosecond pulses of ultraviolet and soft X-ray electromagnetic field at a wavelength of 235 nm.

  12. X-ray nanotomography

    NASA Astrophysics Data System (ADS)

    Sasov, Alexander

    2004-10-01

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

  13. Microgap x-ray detector

    SciTech Connect

    Wuest, Craig R.; Bionta, Richard M.; Ables, Elden

    1994-01-01

    An x-ray detector which provides for the conversion of x-ray photons into photoelectrons and subsequent amplification of these photoelectrons through the generation of electron avalanches in a thin gas-filled region subject to a high electric potential. The detector comprises a cathode (photocathode) and an anode separated by the thin, gas-filled region. The cathode may comprise a substrate, such a beryllium, coated with a layer of high atomic number material, such as gold, while the anode can be a single conducting plane of material, such as gold, or a plane of resistive material, such as chromium/silicon monoxide, or multiple areas of conductive or resistive material, mounted on a substrate composed of glass, plastic or ceramic. The charge collected from each electron avalanche by the anode is passed through processing electronics to a point of use, such as an oscilloscope.

  14. Microgap x-ray detector

    DOEpatents

    Wuest, C.R.; Bionta, R.M.; Ables, E.

    1994-05-03

    An x-ray detector is disclosed which provides for the conversion of x-ray photons into photoelectrons and subsequent amplification of these photoelectrons through the generation of electron avalanches in a thin gas-filled region subject to a high electric potential. The detector comprises a cathode (photocathode) and an anode separated by the thin, gas-filled region. The cathode may comprise a substrate, such a beryllium, coated with a layer of high atomic number material, such as gold, while the anode can be a single conducting plane of material, such as gold, or a plane of resistive material, such as chromium/silicon monoxide, or multiple areas of conductive or resistive material, mounted on a substrate composed of glass, plastic or ceramic. The charge collected from each electron avalanche by the anode is passed through processing electronics to a point of use, such as an oscilloscope. 3 figures.

  15. Quantitative Measurements of X-ray Intensity

    SciTech Connect

    Haugh, M. J., Schneider, M.

    2011-09-01

    This chapter describes the characterization of several X-ray sources and their use in calibrating different types of X-ray cameras at National Security Technologies, LLC (NSTec). The cameras are employed in experimental plasma studies at Lawrence Livermore National Laboratory (LLNL), including the National Ignition Facility (NIF). The sources provide X-rays in the energy range from several hundred eV to 110 keV. The key to this effort is measuring the X-ray beam intensity accurately and traceable to international standards. This is accomplished using photodiodes of several types that are calibrated using radioactive sources and a synchrotron source using methods and materials that are traceable to the U.S. National Institute of Standards and Technology (NIST). The accreditation procedures are described. The chapter begins with an introduction to the fundamental concepts of X-ray physics. The types of X-ray sources that are used for device calibration are described. The next section describes the photodiode types that are used for measuring X-ray intensity: power measuring photodiodes, energy dispersive photodiodes, and cameras comprising photodiodes as pixel elements. Following their description, the methods used to calibrate the primary detectors, the power measuring photodiodes and the energy dispersive photodiodes, as well as the method used to get traceability to international standards are described. The X-ray source beams can then be measured using the primary detectors. The final section then describes the use of the calibrated X-ray beams to calibrate X-ray cameras. Many of the references are web sites that provide databases, explanations of the data and how it was generated, and data calculations for specific cases. Several general reference books related to the major topics are included. Papers expanding some subjects are cited.

  16. Lumbosacral spine x-ray

    MedlinePlus

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

  17. Toward active x-ray telescopes

    NASA Astrophysics Data System (ADS)

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

    2011-09-01

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

  18. Toward Adaptive X-Ray Telescopes

    NASA Technical Reports Server (NTRS)

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

    2011-01-01

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

  19. Technological Challenges to X-Ray FELs

    SciTech Connect

    Nuhn, Heinz-Dieter

    1999-09-16

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

  20. Technological challenges to X-ray FELs

    NASA Astrophysics Data System (ADS)

    Nuhn, Heinz-Dieter

    2000-05-01

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

  1. 21 CFR 892.1720 - Mobile x-ray system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Mobile x-ray system. 892.1720 Section 892.1720...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1720 Mobile x-ray system. (a) Identification. A mobile x-ray system is a transportable device system intended to be used to generate and control...

  2. 21 CFR 892.1680 - Stationary x-ray system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Stationary x-ray system. 892.1680 Section 892.1680...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1680 Stationary x-ray system. (a) Identification. A stationary x-ray system is a permanently installed diagnostic system intended to generate...

  3. 21 CFR 892.1720 - Mobile x-ray system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Mobile x-ray system. 892.1720 Section 892.1720...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1720 Mobile x-ray system. (a) Identification. A mobile x-ray system is a transportable device system intended to be used to generate and control...

  4. 21 CFR 892.1720 - Mobile x-ray system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Mobile x-ray system. 892.1720 Section 892.1720...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1720 Mobile x-ray system. (a) Identification. A mobile x-ray system is a transportable device system intended to be used to generate and control...

  5. 21 CFR 892.1720 - Mobile x-ray system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Mobile x-ray system. 892.1720 Section 892.1720...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1720 Mobile x-ray system. (a) Identification. A mobile x-ray system is a transportable device system intended to be used to generate and control...

  6. 21 CFR 892.1680 - Stationary x-ray system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Stationary x-ray system. 892.1680 Section 892.1680...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1680 Stationary x-ray system. (a) Identification. A stationary x-ray system is a permanently installed diagnostic system intended to generate...

  7. 21 CFR 892.1720 - Mobile x-ray system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Mobile x-ray system. 892.1720 Section 892.1720...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1720 Mobile x-ray system. (a) Identification. A mobile x-ray system is a transportable device system intended to be used to generate and control...

  8. 21 CFR 892.1680 - Stationary x-ray system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Stationary x-ray system. 892.1680 Section 892.1680...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1680 Stationary x-ray system. (a) Identification. A stationary x-ray system is a permanently installed diagnostic system intended to generate...

  9. 21 CFR 892.1680 - Stationary x-ray system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Stationary x-ray system. 892.1680 Section 892.1680...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1680 Stationary x-ray system. (a) Identification. A stationary x-ray system is a permanently installed diagnostic system intended to generate...

  10. 21 CFR 892.1680 - Stationary x-ray system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Stationary x-ray system. 892.1680 Section 892.1680...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1680 Stationary x-ray system. (a) Identification. A stationary x-ray system is a permanently installed diagnostic system intended to generate...

  11. Phosphor Scanner For Imaging X-Ray Diffraction

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

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

  12. Stable High-Brightness Electron Beam System with a Photocathode RF Gun for Short Pulse X-Ray Generation by Thomson Scattering

    NASA Astrophysics Data System (ADS)

    Sakai, Fumio; Yang, Jinfeng; Yorozu, Masafumi; Okada, Yasuhiro; Yanagida, Tatsuya; Endo, Akira

    2002-03-01

    A high-brightness electron accelerator system with a photocathode RF gun and an all-solid stable laser for the photocathode was installed, and a commissioning test was performed to generate short-pulse X-ray beams by the Thomson scattering method. Electron energy was boosted by a linear accelerator (linac) up to 14 MeV. Energy dispersion of the electron beams was measured to be 0.7% (rms). The normalized emittance of the electron beam was 4 πmm-mrad with a 0.4 nC bunch charge. The electron beam size at the interaction point, where the electron beams and high peak power laser light interacted, was measured to be 100 μm (rms). Good stability in the spatial and temporal domains was also obtained.

  13. TU-A-9A-07: X-Ray Acoustic Computed Tomography (XACT): 100% Sensitivity to X-Ray Absorption

    SciTech Connect

    Xiang, L; Ahmad, M; Nikoozadeh, A; Pratx, G; Khuri-Yakub, B; Xing, L

    2014-06-15

    Purpose: To assess whether X-ray acoustic computed tomography (XACT) is more sensitive to X-ray absorption than that of the conventional X-ray imaging. Methods: First, a theoretical model was built to analyze the X-ray absorption sensitivity of XACT imaging and conventional X-ray imaging. Second, an XACT imaging system was developed to evaluate the X-ray induced acoustic signal generation as well as the sensitivity improvement over transmission x-ray imaging. Ultra-short x-ray pulses (60-nanosecond) were generated from an X-ray source operated at the energy of 150 kVp with a 10-Hz repetition rate. The X-ray pulse was synchronized with the acoustic detection via a x-ray scintillation triggering to acquire the X-ray induced acoustic signal. Results: Theoretical analysis shows that X-ray induced acoustic signal is sensitive only to the X-ray absorption, while completely insensitive to out the X-ray scattering and fluorescence. XACT has reduced background and increased contrast-to-noise ratio, and therefore has increased sensitivity compared to transmission x-ray imaging. For a 50-μm size, gadolinium insertion in tissue exposed to 40 keV X-rays; the sensitivity of XACT imaging is about 28.9 times higher than that of conventional X-ray imaging. Conclusion: X-ray acoustic computer tomography (XACT) as a new imaging modality combines X-ray absorption contrast and high ultrasonic resolution in a single modality. It is feasible to improve the imaging sensitivity with XACT imaging compared with conventional X-ray imaging. Taking advantage of the high ultrasonic resolution, it is possible to perform 3-D imaging with a single x-ray pulse with arrays of transducers without any mechanical motion of the imaging system. This single-shot capability offers the potential of reducing radiation dose by a factor of 1000, and imaging 100 times faster when compared to the conventional X-ray CT, and thus revolutionizing x-ray imaging applications in medicine and biology. The authors

  14. X-Ray Detector for 1 to 30 keV

    NASA Technical Reports Server (NTRS)

    Alcorn, G.; Jackson, J., Jr; Grant, P.; Marshall, F.

    1983-01-01

    Array of silicon X-ray detecting diodes measures photon energy and provides image of X-ray pattern. Regardless of thickness of new X-ray detector, depletion region extends through it. Impinging X-rays generate electrons in quantities proportional to X-ray energy. X-ray detector is mated to chargecoupled-device array for image generation and processing. Useful in industrial part inspection, pulsed-plasma research and medical application.

  15. Compact X-ray sources: X-rays from self-reflection

    NASA Astrophysics Data System (ADS)

    Mangles, Stuart P. D.

    2012-05-01

    Laser-based particle acceleration offers a way to reduce the size of hard-X-ray sources. Scientists have now developed a simple scheme that produces a bright flash of hard X-rays by using a single laser pulse both to generate and to scatter an electron beam.

  16. X-ray beam finder

    DOEpatents

    Gilbert, H.W.

    1983-06-16

    An X-ray beam finder for locating a focal spot of an X-ray tube includes a mass of X-ray opaque material having first and second axially-aligned, parallel-opposed faces connected by a plurality of substantially identical parallel holes perpendicular to the faces and a film holder for holding X-ray sensitive film tightly against one face while the other face is placed in contact with the window of an X-ray head.

  17. X-ray astronomical spectroscopy

    NASA Technical Reports Server (NTRS)

    Holt, Stephen S.

    1987-01-01

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

  18.  Generation of low-flux X-ray micro-planar beams and their biological effect on a murine subcutaneous tumor model.

    PubMed

    Hong, Zhengshan; Zenkoh, Junko; Le, Biao; Gerelchuluun, Ariungerel; Suzuki, Kenshi; Moritake, Takashi; Washio, Masakazu; Urakawa, Junji; Tsuboi, Koji

    2015-09-01

    We generated low-flux X-ray micro-planar beams (MPBs) using a laboratory-scale industrial X-ray generator (60 kV/20 mA) with custom-made collimators with three different peak/pitch widths (50/200 μm, 100/400 μm, 50/400 μm). To evaluate normal skin reactions, the thighs of C3H/HeN mice were exposed to 100 and 200 Gy MPBs in comparison with broad beams (20, 30, 40, 50, 60 Gy). Antitumor effects of MPBs were evaluated in C3H/HeN mice with subcutaneous tumors (SCCVII). After the tumors were irradiated with 100 and 200 Gy MPBs and 20 and 30 Gy broad beams, the tumor sizes were measured and survival analyses were performed. In addition, the tumors were excised and immunohistochemically examined to detect γ-H2AX, ki67 and CD34. It was shown that antitumor effects of 200 Gy MPBs at 50/200 μm and 100/400 μm were significantly greater than those of 20 Gy broad beams, and were comparable with 30 Gy broad beams. γ-H2AX-positive cells demonstrated clear stripe-patterns after MPB irradiation; the pattern gradually faded and intermixed over 24 h. The chronological changes in ki67 positivity did not differ between MPBs and broad beams, whereas the CD34-positive area decreased significantly more in MPBs than in broad beams. In addition, it was shown that skin injury after MPB irradiation was significantly milder when compared with broad-beam irradiation at equivalent doses for achieving the same tumor control effect. Bystander effect and tumor vessel injury may be the mechanism contributing to the efficacy of MPBs. PMID:26141370

  19.  Generation of low-flux X-ray micro-planar beams and their biological effect on a murine subcutaneous tumor model

    PubMed Central

    Hong, Zhengshan; Zenkoh, Junko; Le, Biao; Gerelchuluun, Ariungerel; Suzuki, Kenshi; Moritake, Takashi; Washio, Masakazu; Urakawa, Junji; Tsuboi, Koji

    2015-01-01

    We generated low-flux X-ray micro-planar beams (MPBs) using a laboratory-scale industrial X-ray generator (60 kV/20 mA) with custom-made collimators with three different peak/pitch widths (50/200 μm, 100/400 μm, 50/400 μm). To evaluate normal skin reactions, the thighs of C3H/HeN mice were exposed to 100 and 200 Gy MPBs in comparison with broad beams (20, 30, 40, 50, 60 Gy). Antitumor effects of MPBs were evaluated in C3H/HeN mice with subcutaneous tumors (SCCVII). After the tumors were irradiated with 100 and 200 Gy MPBs and 20 and 30 Gy broad beams, the tumor sizes were measured and survival analyses were performed. In addition, the tumors were excised and immunohistochemically examined to detect γ-H2AX, ki67 and CD34. It was shown that antitumor effects of 200 Gy MPBs at 50/200 μm and 100/400 μm were significantly greater than those of 20 Gy broad beams, and were comparable with 30 Gy broad beams. γ-H2AX-positive cells demonstrated clear stripe-patterns after MPB irradiation; the pattern gradually faded and intermixed over 24 h. The chronological changes in ki67 positivity did not differ between MPBs and broad beams, whereas the CD34-positive area decreased significantly more in MPBs than in broad beams. In addition, it was shown that skin injury after MPB irradiation was significantly milder when compared with broad-beam irradiation at equivalent doses for achieving the same tumor control effect. Bystander effect and tumor vessel injury may be the mechanism contributing to the efficacy of MPBs. PMID:26141370

  20. X-ray induced singlet oxygen generation by nanoparticle-photosensitizer conjugates for photodynamic therapy: determination of singlet oxygen quantum yield.

    PubMed

    Clement, Sandhya; Deng, Wei; Camilleri, Elizabeth; Wilson, Brian C; Goldys, Ewa M

    2016-01-01

    Singlet oxygen is a primary cytotoxic agent in photodynamic therapy. We show that CeF3 nanoparticles, pure as well as conjugated through electrostatic interaction with the photosensitizer verteporfin, are able to generate singlet oxygen as a result of UV light and 8 keV X-ray irradiation. The X-ray stimulated singlet oxygen quantum yield was determined to be 0.79 ± 0.05 for the conjugate with 31 verteporfin molecules per CeF3 nanoparticle, the highest conjugation level used. From this result we estimate the singlet oxygen dose generated from CeF3-verteporfin conjugates for a therapeutic dose of 60 Gy of ionizing radiation at energies of 6 MeV and 30 keV to be (1.2 ± 0.7) × 10(8) and (2.0 ± 0.1) × 10(9) singlet oxygen molecules per cell, respectively. These are comparable with cytotoxic doses of 5 × 10(7)-2 × 10(9) singlet oxygen molecules per cell reported in the literature for photodynamic therapy using light activation. We confirmed that the CeF3-VP conjugates enhanced cell killing with 6 MeV radiation. This work confirms the feasibility of using X- or γ- ray activated nanoparticle-photosensitizer conjugates, either to supplement the radiation treatment of cancer, or as an independent treatment modality. PMID:26818819

  1. X-ray induced singlet oxygen generation by nanoparticle-photosensitizer conjugates for photodynamic therapy: determination of singlet oxygen quantum yield

    PubMed Central

    Clement, Sandhya; Deng, Wei; Camilleri, Elizabeth; Wilson, Brian C.; Goldys, Ewa M.

    2016-01-01

    Singlet oxygen is a primary cytotoxic agent in photodynamic therapy. We show that CeF3 nanoparticles, pure as well as conjugated through electrostatic interaction with the photosensitizer verteporfin, are able to generate singlet oxygen as a result of UV light and 8 keV X-ray irradiation. The X-ray stimulated singlet oxygen quantum yield was determined to be 0.79 ± 0.05 for the conjugate with 31 verteporfin molecules per CeF3 nanoparticle, the highest conjugation level used. From this result we estimate the singlet oxygen dose generated from CeF3-verteporfin conjugates for a therapeutic dose of 60 Gy of ionizing radiation at energies of 6 MeV and 30 keV to be (1.2 ± 0.7) × 108 and (2.0 ± 0.1) × 109 singlet oxygen molecules per cell, respectively. These are comparable with cytotoxic doses of 5 × 107–2 × 109 singlet oxygen molecules per cell reported in the literature for photodynamic therapy using light activation. We confirmed that the CeF3-VP conjugates enhanced cell killing with 6 MeV radiation. This work confirms the feasibility of using X- or γ- ray activated nanoparticle-photosensitizer conjugates, either to supplement the radiation treatment of cancer, or as an independent treatment modality. PMID:26818819

  2. X-ray induced singlet oxygen generation by nanoparticle-photosensitizer conjugates for photodynamic therapy: determination of singlet oxygen quantum yield

    NASA Astrophysics Data System (ADS)

    Clement, Sandhya; Deng, Wei; Camilleri, Elizabeth; Wilson, Brian C.; Goldys, Ewa M.

    2016-01-01

    Singlet oxygen is a primary cytotoxic agent in photodynamic therapy. We show that CeF3 nanoparticles, pure as well as conjugated through electrostatic interaction with the photosensitizer verteporfin, are able to generate singlet oxygen as a result of UV light and 8 keV X-ray irradiation. The X-ray stimulated singlet oxygen quantum yield was determined to be 0.79 ± 0.05 for the conjugate with 31 verteporfin molecules per CeF3 nanoparticle, the highest conjugation level used. From this result we estimate the singlet oxygen dose generated from CeF3-verteporfin conjugates for a therapeutic dose of 60 Gy of ionizing radiation at energies of 6 MeV and 30 keV to be (1.2 ± 0.7) × 108 and (2.0 ± 0.1) × 109 singlet oxygen molecules per cell, respectively. These are comparable with cytotoxic doses of 5 × 107-2 × 109 singlet oxygen molecules per cell reported in the literature for photodynamic therapy using light activation. We confirmed that the CeF3-VP conjugates enhanced cell killing with 6 MeV radiation. This work confirms the feasibility of using X- or γ- ray activated nanoparticle-photosensitizer conjugates, either to supplement the radiation treatment of cancer, or as an independent treatment modality.

  3. Large Area X-Ray Spectroscopy Mission

    NASA Technical Reports Server (NTRS)

    Tananbaum, H.

    1997-01-01

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

  4. X-ray

    MedlinePlus

    ... Most experts feel that the benefits of appropriate x-ray imaging greatly outweigh any risks. Young children and babies ... be pregnant. Alternative Names ... CM, eds. Grainger & Allison's Diagnostic Radiology: A Textbook of Medical Imaging . 6th ed. Philadelphia, PA: Elsevier Churchill Livingstone; 2014: ...

  5. X-rays and Planet Formation

    NASA Astrophysics Data System (ADS)

    Feigelson, E. D.

    2005-12-01

    Planets form in cold circumstellar disks that can not emit X-rays. Nonetheless, X-ray band studies may have profound implications for the physical processes of planet formation in several ways. Observations of young stellar clusters, such as the recent Chandra Orion Ultradeep Project (COUP), demonstrate that all pre-main sequence stars produce powerful magnetic reconnection flares during the planet formation era. Calculations indicate that the X-rays can penetrate deeply into protoplanetary disks and will be the dominant source of gas ionization. COUP observations of fluorescent line emission in heavy disk stars and soft X-ray absorption in proplyds demonstrate that disk irradiation by X-rays does in fact occur. This may induce MHD turbulence in disk gases, which may substantially affect planetesimal growth and protoplanet migration. X-ray flares or associated shock waves may flash melt dustballs into chondrules, and spallation by energetic flare particles may generate shortlived radioactive isotopes which are prevalent in the meteoritic record. X-ray surveys are also useful for locating older stellar systems where the protoplanetary disk is dissipating but magnetic flaring continues. Infrared studies of such systems show a great diversity of older disk properties. The planned Constellation-X mission will propel all of these investigations in powerful ways. For example, reverberation mapping of fluorescent line emission following flares could give unique insights into the structure of the gaseous components of protoplanetary disks.

  6. A laser-plasma-produced soft X-ray laser at 89 eV generates DNA double-strand breaks in human cancer cells.

    PubMed

    Sato, Katsutoshi; Nishikino, Masaharu; Kawachi, Tetsuya; Shimokawa, Takashi; Imai, Takashi; Teshima, Teruki; Nishimura, Hiroaki; Kando, Masaki

    2015-07-01

    While it has been expected that X-ray laser will be widely applied to biomedical studies, this has not been achieved to date and its biological effects such as DNA damage have not been evaluated. As a first step for its biological application, we developed a culture cell irradiation system, particularly designed for a plasma-driven soft X-ray laser pulse, to investigate whether the soft X-ray laser is able to induce DNA double strand breaks (DSBs) in living cells or not. The human adenocarcimona cell line A549 was irradiated with the soft X-ray laser at a photon energy of 89 eV and the repair focus formation of the DSBs was assessed by immunofluorescence staining with antiphosphorylated DNA-PKcs (p-DNA-PKcs), ATM (p-ATM) and γ-H2AX antibody. The p-DNA-PKcs, ATM, and γ-H2AX foci were clearly identified after soft X-ray laser irradiation. Furthermore, the increase in the X-ray laser shot number, even from a single shot, results in the increase in p-DNA-PKcs foci. These results are the first evidence that the 89 eV soft X-ray laser is able to induce DSB in living cells. Our study demonstrated that this irradiation system is a useful tool for investigating the radiobiological effect of soft X-ray laser. PMID:25862698

  7. A laser-plasma–produced soft X-ray laser at 89 eV generates DNA double-strand breaks in human cancer cells

    PubMed Central

    Sato, Katsutoshi; Nishikino, Masaharu; Kawachi, Tetsuya; Shimokawa, Takashi; Imai, Takashi; Teshima, Teruki; Nishimura, Hiroaki; Kando, Masaki

    2015-01-01

    While it has been expected that X-ray laser will be widely applied to biomedical studies, this has not been achieved to date and its biological effects such as DNA damage have not been evaluated. As a first step for its biological application, we developed a culture cell irradiation system, particularly designed for a plasma-driven soft X-ray laser pulse, to investigate whether the soft X-ray laser is able to induce DNA double strand breaks (DSBs) in living cells or not. The human adenocarcimona cell line A549 was irradiated with the soft X-ray laser at a photon energy of 89 eV and the repair focus formation of the DSBs was assessed by immunofluorescence staining with antiphosphorylated DNA-PKcs (p-DNA-PKcs), ATM (p-ATM) and γ-H2AX antibody. The p-DNA-PKcs, ATM, and γ-H2AX foci were clearly identified after soft X-ray laser irradiation. Furthermore, the increase in the X-ray laser shot number, even from a single shot, results in the increase in p-DNA-PKcs foci. These results are the first evidence that the 89 eV soft X-ray laser is able to induce DSB in living cells. Our study demonstrated that this irradiation system is a useful tool for investigating the radiobiological effect of soft X-ray laser. PMID:25862698

  8. Second-harmonic generation and x-ray diffraction studies of the pretransitional region and polar phase in relaxor K(1-x)LixTaO3

    NASA Astrophysics Data System (ADS)

    Yokota, Hiroko; Uesu, Yoshiaki; Malibert, Charlotte; Kiat, Jean-Michel

    2007-05-01

    Optical second-harmonic generation (SHG) observations and precise x-ray diffraction experiments have been performed on quantum paraelectrics KTaO3 (KTO) and relaxors K(1-x)LixTaO3 with x=3% (KLT-3) and 7% (KLT-7). It is found in KLT-3 and KLT-7 that a pretransitional region exists between two characteristic temperatures TB and Tp(x-ray diffraction experiments. The Landau-Devonshire phenomenological approach suggests that the ferroelectric phase transition at Tp is of first order and that it approaches the second-order transition with a decrease in the Li concentration. A marked increase of neutron-diffraction intensities below Tp , together with the disappearance of SHG intensity in a ZFC run, indicates that PNRs are transformed to ferroelectric microdomains at Tp . The microdomains become macroscopic below Tp in the FC process. In the lower-temperature region, nonergodic behavior was observed: The ZFC state cannot approach the thermodynamically equilibrium state under the electric field within finite time.

  9. First in-situ monitoring of CO2 delivery to the mantle followed by compression melting, using synchrotron generated X-ray diffraction.

    NASA Astrophysics Data System (ADS)

    Hammouda, Tahar; Chantel, Julien; Manthilake, Geeth; Guignard, Jérémy; Crichton, Wilson; Gaillard, Fabrice

    2014-05-01

    Melting of peridotite + CO2 upon compression has been directly monitored in situ, for the first time. We have combined high pressure experiments in the multianvil apparatus with synchrotron-generated X-ray diffraction, in order to monitor sample decarbonation upon heating, followed by melting upon compression. Experiments were performed in the model system CaO-MgO-SiO2+CO2, using dolomite and silicates contained in graphite capsules as starting material. Save Al, starting composition was aimed at reproducing peridotitic system. The sample was first compressed at room temperature, then heated. Decarbonation was observed at 2.2 GPa and 1100°C. After further heating to 1300°C, pressure was increased. Melting was observed at 2.7 GPa, while temperature was kept at 1300°C. All transformations were followed using X-ray diffraction. Starting with silicate + carbonate mixtures, we were thus able to keep CO2 fluid in the experimental sample at high P and T, up to the solidus. Concerning carbon recycling at subduction zones, it is known that CO2 is a non-wetting fluid in silicate aggregates. Therefore, any CO2 resulting from carbonate breakdown likely remains trapped at grain corners either in the subducted lithosphere or in the mantle wedge before eventually being trapped in mantle minerals as fluid inclusions, due to dynamic recrystallization. In this way, CO2 released from the slab may be spread laterally due to mantle convection. Entrainment to further depths by deep subduction or in convection cells induces CO2 introduction to depth wherein the solidus can be crossed, due to pressure increase. The solidus corresponds to the so-called carbonate ledge, beyond which carbonatitic melts are produced. Therefore, compression melting of CO2-bearing lithologies is a way to produce carbonatitic melts at depths corresponding to about 80 km. This mechanism is a viable explanation for the observed geophysical anomalies, such as those revealed by electrical conductivity

  10. A new x-ray scatter reduction method based on frequency division multiplexing x-ray imaging technique

    NASA Astrophysics Data System (ADS)

    Zhang, J.; Chang, S.; Lu, J. P.; Zhou, O.

    2012-03-01

    X-ray scatter may significantly degrade imaging performance in x-ray radiography applications, including flatpanel detector-based x-ray imaging, tomosynthesis, and cone-beam CT (CBCT), primarily due to their large projection field sizes. It results in soft tissue contrast reduction, potentially severe image artifacts, and increased patient dose. Several different approaches have been developed to reject the scatter contributions, including analytical calculation, empirical algorithms, Monte-Carlo simulation, blocker based measurement, and slot scan technique. We recently developed a new x-ray scatter rejection method based on nanotechnology-enabled frequency division multiplexing x-ray (FDMX) imaging technique. The key enabling technology is the carbon nanotube (CNT)-based multi-beam field emission x-ray (MBFEX) source technology. The proposed FDMX imaging system has a MBFEX source with an array of x-ray tubes. The x-ray radiation from each individual x-ray tube is modulated at a certain given frequency. The collimated x-ray beams passed through the object and were captured by a high speed x-ray detector. A demultiplexing algorithm was applied to reject the scatter radiation from the primary radiation based on their different modulation frequencies. The x-ray images generated by the FDMX imaging technique clearly demonstrated improved imaging quality in terms of lower scatter-to-primary-ratio (SPR) and higher contrast-to-noise-ratio (CNR). It shows great potential of improving x-ray imaging performance and reducing patient dose.

  11. X-ray apparatus for tomosynthesis

    SciTech Connect

    Klotz, E.; Linde, R.; Tiemens, U.; Weiss, H.

    1981-01-20

    Apparatus for examining objects includes a group of x-ray sources, which are activated group-wise by a generator. A group of sub-images are separately projected onto a photographic film. During a subsequent step, the film is re-imaged with the aid of an optical lens matrix the lenses in the matrix are arranged in a manner similar to the x-ray sources.

  12. Production of exotic states of matter with the use of X-rays generated by focusing a petawatt laser pulse onto a solid target

    NASA Astrophysics Data System (ADS)

    Pikuz (Jr. , S. A.; Faenov, A. Ya; Fortov, V. E.; Skobelev, I. Yu

    2014-07-01

    The possibility is discussed of using optical laser radiation with an intensity of >1020~W cm -2 to create an ultraintense X-ray source capable of producing polychromatic radiation with a power flux of 1019~W cm -2 or higher. X-ray radiation of so high an intensity permits not only transforming a condensed matter of the target into a plasma state but also obtaining an exotic plasma state with a high density of hollow ions. Currently not yet in wide use and available in only a few laboratories in the world, lasers with a radiation intensity of about 1020~W cm -2 are more compact and less expensive than free-electron X-ray lasers or lasers used for the indirect heating of fusion targets. The source under discussion can produce by far higher X-ray intensities than plasma X-ray lasers of a similar scale.

  13. SAS 3 survey of the soft X-ray background

    NASA Technical Reports Server (NTRS)

    Marshall, F. J.; Clark, G. W.

    1984-01-01

    The results of a survey of the soft X-ray sky in the C band (0.10-0.28keV) are reported. The observations were carried out using two independent flow proportional counters on board the SAS 3 X-ray satellite which had a total angular resolution of 2.9 deg FWHM, and a total exposure of 2.2 x 10 to the 4th per sq cm s sr. It is found that C band counting rates were generally inversely correlated with the column density of the neutral hydrogen on all angular scales down to the lowest angular resolution of the detectors. In the region 90-180 deg l and 0-10 deg b, the relation between C-band rates and the column densities of neutral hydrogen was fitted with a residual rms deviation of less than 13 percent by a two-component numerical model of the X-ray background. For the apparent attenuation column density a value of 2.7 x 10 to the 20th per sq cm was obtained. On the basis of a computer simulation of the SAS 3 data, it is shown that the observed clumping of interstellar matter was consistent with the magnitude of spatial fluctuations in the C-band map. When the background rates were subtracted from the survey map, the subsequent map showed foreground emission and absorption features with improved sensitivity and clarity. A series of computer-generated maps incorporating the SAS 3 data is given in an appendix.

  14. Time frame generator for x-ray detectors and data acquisition systems for synchrotron radiation applications in molecular biology

    SciTech Connect

    Khazaie, J.B.; Boulin, C.

    1996-02-01

    The authors present a fully programmable controller module designed to generate the synchronization and control signals required to conduct time-resolved synchrotron radiation experiments to study biological macromolecules. This module is organized around an 8K (24-bit world) fast SRAM that contains the description of up to 4,096 pairs of wait and active time frames to gate the data collection. Most of the control logic is integrated into an Xilinx XC4000 family logic cell array.

  15. Next generation of Z* modelling tool for high intensity EUV and soft x-ray plasma sources simulations

    NASA Astrophysics Data System (ADS)

    Zakharov, S. V.; Zakharov, V. S.; Choi, P.; Krukovskiy, A. Y.; Novikov, V. G.; Solomyannaya, A. D.; Berezin, A. V.; Vorontsov, A. S.; Markov, M. B.; Parot'kin, S. V.

    2011-04-01

    In the specifications for EUV sources, high EUV power at IF for lithography HVM and very high brightness for actinic mask and in-situ inspections are required. In practice, the non-equilibrium plasma dynamics and self-absorption of radiation limit the in-band radiance of the plasma and the usable radiation power of a conventional single unit EUV source. A new generation of the computational code Z* is currently developed under international collaboration in the frames of FP7 IAPP project FIRE for modelling of multi-physics phenomena in radiation plasma sources, particularly for EUVL. The radiation plasma dynamics, the spectral effects of self-absorption in LPP and DPP and resulting Conversion Efficiencies are considered. The generation of fast electrons, ions and neutrals is discussed. Conditions for the enhanced radiance of highly ionized plasma in the presence of fast electrons are evaluated. The modelling results are guiding a new generation of EUV sources being developed at Nano-UV, based on spatial/temporal multiplexing of individual high brightness units, to deliver the requisite brightness and power for both lithography HVM and actinic metrology applications.

  16. Generation of circularly polarized radiation from a compact plasma-based extreme ultraviolet light source for tabletop X-ray magnetic circular dichroism studies

    SciTech Connect

    Wilson, Daniel; Rudolf, Denis Juschkin, Larissa; Weier, Christian; Adam, Roman; Schneider, Claus M.; Winkler, Gerrit; Frömter, Robert; Danylyuk, Serhiy; Bergmann, Klaus; Grützmacher, Detlev

    2014-10-15

    Generation of circularly polarized light in the extreme ultraviolet (EUV) spectral region (about 25 eV–250 eV) is highly desirable for applications in spectroscopy and microscopy but very challenging to achieve in a small-scale laboratory. We present a compact apparatus for generation of linearly and circularly polarized EUV radiation from a gas-discharge plasma light source between 50 eV and 70 eV photon energy. In this spectral range, the 3p absorption edges of Fe (54 eV), Co (60 eV), and Ni (67 eV) offer a high magnetic contrast often employed for magneto-optical and electron spectroscopy as well as for magnetic imaging. We simulated and designed an instrument for generation of linearly and circularly polarized EUV radiation and performed polarimetric measurements of the degree of linear and circular polarization. Furthermore, we demonstrate first measurements of the X-ray magnetic circular dichroism at the Co 3p absorption edge with a plasma-based EUV light source. Our approach opens the door for laboratory-based, element-selective spectroscopy of magnetic materials and spectro-microscopy of ferromagnetic domains.

  17. Laboratory Data for X-Ray Astronomy

    NASA Technical Reports Server (NTRS)

    Beiersdorfer, P.; Brown, G. V.; Chen, H.; Gu, M.-F.; Kahn, S. M.; Lepson, J. K.; Savin, D. W.; Utter, S. B.

    2000-01-01

    Laboratory facilities have made great strides in producing large sets of reliable data for X-ray astronomy, which include ionization and recombination cross sections needed for charge balance calculations as well as the atomic data needed for interpreting X-ray line formation. We discuss data from the new generation sources and pay special attention to the LLNL electron beam ion trap experiment, which is unique in its ability to provide direct laboratory access to spectral data under precisely controlled conditions that simulate those found in many astrophysical plasmas. Examples of spectral data obtained in the 1-160 A wavelength range are given illustrating the type of laboratory X-ray data produced in support of such missions as Chandra, X-Ray Multi-Mirror telescope (XMM), Advanced Satellite for Cosmology and Astrophysics (ASCA) and Extreme Ultraviolet Explorer Satellite (EUVE).

  18. X-Ray Astronomy

    NASA Technical Reports Server (NTRS)

    Wu, S. T.

    2000-01-01

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

  19. X-ray Spectrometer

    NASA Technical Reports Server (NTRS)

    Porter, F. Scott

    2004-01-01

    The X-ray Spectrometer (XRS) instrument is a revolutionary non-dispersive spectrometer that will form the basis for the Astro-E2 observatory to be launched in 2005. We have recently installed a flight spare X R S microcalorimeter spectrometer at the EBIT-I facility at LLNL replacing the XRS from the earlier Astro-E mission and providing twice the resolution. The X R S microcalorimeter is an x-ray detector that senses the heat deposited by the incident photon. It achieves a high energy resolution by operating at 0.06K and by carefully controlling the heat capacity and thermal conductance. The XRS/EBIT instrument has 32 pixels in a square geometry and achieves an energy resolution of 6 eV at 6 keV, with a bandpass from 0.1 to 12 keV (or more at higher operating temperature). The instrument allows detailed studies of the x-ray line emission of laboratory plasmas. The XRS/EBIT also provides an extensive calibration "library" for the Astro-E2 observatory.

  20. Monitoring X-Ray Emission from X-Ray Bursters

    NASA Technical Reports Server (NTRS)

    Kaaret, Philip

    1998-01-01

    The goal of this investigation was to use the All-Sky Monitor on the Rossi X-Ray Timing Explorer (RXTE) in combination with the Burst and Transient Source Experiment on the Compton Gamma-Ray Observatory to simultaneously measure the x-ray (2-12 keV) and hard x-ray (20-100 keV) emission from x-ray bursters. The investigation was successful. We made the first simultaneous measurement of hard and soft x-ray emission and found a strong anticorrelation of hard and soft x-ray emission from the X-Ray Burster 4U 0614+091. The monitoring performed under this investigation was also important in triggering target of opportunity observations of x-ray bursters made under the investigation hard x-ray emission of x-ray bursters approved for RXTE cycles 1 and 2. These observations lead to a number of papers on high-frequency quasi-periodic oscillations and on hard x-ray emission from the x-ray bursters 4U 0614+091 and 4U 1705-44.

  1. Development of a lab-scale, high-resolution, tube-generated X-ray computed-tomography system for three-dimensional (3D) materials characterization

    SciTech Connect

    Mertens, J.C.E. Williams, J.J. Chawla, Nikhilesh

    2014-06-01

    The design and construction of a modular high resolution X-ray computed tomography (XCT) system is highlighted in this paper. The design approach is detailed for meeting a specified set of instrument performance goals tailored towards experimental versatility and high resolution imaging. The XCT tool is unique in the detector and X-ray source design configuration, enabling control in the balance between detection efficiency and spatial resolution. The system package is also unique: The sample manipulation approach implemented enables a wide gamut of in situ experimentation to analyze structure evolution under applied stimulus, by optimizing scan conditions through a high degree of controllability. The component selection and design process is detailed: Incorporated components are specified, custom designs are shared, and the approach for their integration into a fully functional XCT scanner is provided. Custom designs discussed include the dual-target X-ray source cradle which maintains position and trajectory of the beam between the two X-ray target configurations with respect to a scintillator mounting and positioning assembly and the imaging sensor, as well as a novel large-format X-ray detector with enhanced adaptability. The instrument is discussed from an operational point of view, including the details of data acquisition and processing implemented for 3D imaging via micro-CT. The performance of the instrument is demonstrated on a silica-glass particle/hydroxyl-terminated-polybutadiene (HTPB) matrix binder PBX simulant. Post-scan data processing, specifically segmentation of the sample's relevant microstructure from the 3D reconstruction, is provided to demonstrate the utility of the instrument. - Highlights: • Custom built X-ray tomography system for microstructural characterization • Detector design for maximizing polychromatic X-ray detection efficiency • X-ray design offered for maximizing X-ray flux with respect to imaging resolution • Novel lab

  2. X-ray laser driven gold targets

    SciTech Connect

    Petrova, Tz. B. Whitney, K. G.; Davis, J.

    2014-03-15

    The femtosecond population dynamics of gold irradiated by a coherent high-intensity (>10{sup 17} W/cm{sup 2}) x-ray laser pulse is investigated theoretically. There are two aspects to the assembled model. One is the construction of a detailed model of platinum-like gold inclusive of all inner-shell states that are created by photoionization of atomic gold and decay either by radiative or Auger processes. Second is the computation of the population dynamics that ensues when an x-ray pulse is absorbed in gold. The hole state generation depends on the intensity and wavelength of the driving x-ray pulse. The excited state populations reached during a few femtosecond timescales are high enough to generate population inversions, whose gain coefficients are calculated. These amplified lines in the emitted x-ray spectrum provide important diagnostics of the radiation dynamics and also suggest a nonlinear way to increase the frequency of the coherent output x-ray pulses relative to the frequency of the driver input x-ray pulse.

  3. Apparatus for monitoring X-ray beam alignment

    DOEpatents

    Steinmeyer, Peter A.

    1991-10-08

    A self-contained, hand-held apparatus is provided for minitoring 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.

  4. Apparatus for monitoring X-ray beam alignment

    DOEpatents

    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.

  5. Techniques of absolute low energy x-ray calibration

    SciTech Connect

    Day, R.H.

    1986-01-01

    Recent advances in pulsed plasma research, materials science, and astrophysics have required many new diagnostic instruments for use in the low energy x-ray regime. The characterization of these instruments has provided a challenge to instrument designers and provided the momentum to improve x-ray sources and dosimetry techniques. In this paper, the present state-of-the-art in low energy x-ray characterization techniques is reviewed. A summary is given of low energy x-ray generator technology and dosimetry techniques including a discussion of thin window proportional counters and ionization chambers. A review is included of the widely used x-ray data bases and a sample of ultrasoft x-ray measuring procedures, chopped x-ray source generators, phase sensitive detection of ultralow currents, and angular divergence measurements.

  6. Proceedings of the workshop on X-ray computed microtomography

    SciTech Connect

    1998-02-01

    This report consists of vugraphs from the nine presentations at the conference. Titles of the presentations are: CMT: Applications and Techniques; Computer Microtomography Using X-rays from Third Generation Synchrotron X-ray; Approaches to Soft-X-ray Nanotomography; Diffraction Enhanced Tomography; X-ray Computed Microtomography Applications at the NSLS; XCMT Applications in Forestry and Forest Products; 3DMA: Investigating Three Dimensional Pore Geometry from High Resolution Images; X-ray Computed Microtomography Studies of Volcanic Rock; and 3-D Visualization of Tomographic Volumes.

  7. Fluctuation X-Ray Scattering

    SciTech Connect

    Saldin, PI: D. K.; Co-I's: J. C. H. Spence and P. Fromme

    2013-01-25

    The work supported by the grant was aimed at developing novel methods of finding the structures of biomolecules using x-rays from novel sources such as the x-ray free electron laser and modern synchrotrons

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

    NASA Astrophysics Data System (ADS)

    Mertens, J. C. E.; Chawla, Nikhilesh

    2015-05-01

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

  9. Dislocation generation related to micro-cracks in Si wafers: High temperature in situ study with white beam X-ray topography

    NASA Astrophysics Data System (ADS)

    Danilewsky, A.; Wittge, J.; Hess, A.; Cröll, A.; Allen, D.; McNally, P.; Vagovič, P.; Cecilia, A.; Li, Z.; Baumbach, T.; Gorostegui-Colinas, E.; Elizalde, M. R.

    2010-02-01

    The generation and propagation of dislocations in Si at high temperature is observed in situ with white beam X-ray topography. For the heating experiments a double ellipsoidal mirror furnace was installed at the Topo-Tomo beamline of the ANKA synchrotron light source, Research Centre Karlsruhe, Germany. Details of the experimental set-up and the first results on the occurrence of dislocations are presented. Artificial damage was generated in commercial (1 0 0) Si wafers using a nanoindenter with various loads. The applied forces for each set of indents were varied from 100 to 500 mN, respectively. After heating to approx. 790 °C large area transmission topographs were taken every 30 min which were then compared to room temperature topographs before and after heating. At the outset straight 60°-dislocations with b = a/2<1 1 0> originate from the 500 mN indents into the direction of the strongest temperature gradient. After 60 min at constant temperature an increase in the length and number of the dislocations in other directions is also observed. As a result of the continual thermal stressing dislocations develop from the 100 mN indents too.

  10. Self-consistent simulation of an electron beam for a new autoresonant x-ray generator based on TE 102 rectangular mode

    NASA Astrophysics Data System (ADS)

    Dugar-Zhabon, V. D.; Orozco, E. A.; Herrera, A. M.

    2016-02-01

    The space cyclotron autoresonance interaction of an electron beam with microwaves of TE 102 rectangular mode is simulated. It is shown that in these conditions the beam electrons can achieve energies which are sufficient to generate hard x-rays. The physical model consists of a rectangular cavity fed by a magnetron oscillator through a waveguide with a ferrite isolator, an iris window and a system of dc current coils which generates an axially symmetric magnetic field. The 3D magnetic field profile is that which maintains the electron beam in the space autoresonance regime. To simulate the beam dynamics, a full self-consistent electromagnetic particle-in-cell code is developed. It is shown that the injected 12keV electron beam of 0.5A current is accelerated to energy of 225keV at a distance of an order of 17cm by 2.45GHz standing microwave field with amplitude of 14kV/cm.

  11. Electron beam injected into ground generates subsoil x-rays that may deactivate concealed electronics used to trigger explosive devices

    NASA Astrophysics Data System (ADS)

    Retsky, Michael

    2008-04-01

    Explosively formed projectiles (EFP) are a major problem in terrorism and asymmetrical warfare. EFPs are often triggered by ordinary infrared motion detectors. A potential weak link is that such electronics are not hardened to ionizing radiation and can latch-up or enter other inoperative states after exposure to a single short event of ionizing radiation. While these can often be repaired with a power restart, they also can produce shorts and permanent damage. A problem of course is that we do not want to add radiation exposure to the long list of war related hazards. Biological systems are highly sensitive to integrated dosage but show no particular sensitivity to short pulses. There may be a way to generate short pulsed subsoil radiation to deactivate concealed electronics without introducing radiation hazards to military personnel and civilian bystanders. Electron beams of 30 MeV that can be produced by portable linear accelerators (linacs) propagate >20 m in air and 10-12 cm in soil. X-radiation is produced by bremsstrahlung and occurs subsoil beneath the point of impact and is mostly forward directed. Linacs 1.5 m long can produce 66 MWatt pulses of subsoil x-radiation 1 microsecond or less in duration. Untested as yet, such a device could be mounted on a robotic vehicle that precedes a military convoy and deactivates any concealed electronics within 10-20 meters on either side of the road.

  12. Structural factors affecting pore space transformation during hydrocarbon generation in source rock (shales): laboratory experiments and X-ray microtomography/SEM study

    NASA Astrophysics Data System (ADS)

    Giliazetdinova, Dina; Korost, Dmitry; Gerke, Kirill

    2015-04-01

    Oil and gas generation is a complex superposition of processes which take place in the interiors and are not readily observable in nature in human life time-frames. During burial of the source rocks organic matter is transformed into a mixture of high-molecular compounds - precursors of oil and gas (kerogen). Specific thermobaric conditions trigger formation of low molecular weight hydrocarbon compounds. Generation of sufficient quantities of hydrocarbons leads to the primary fluid migration. For series of our experiments we selected mainly siliceous-carbonate composition shale rocks from Domanic horizon of South-Tatar arch. Rock samples were heated in the pyrolyzer to temperatures closely corresponding to different catagenesis stages. X-ray microtomography method was used to monitor changes in the morphology of the pore space within studied shale rocks. By routine measurements we made sure that all samples (10 in total) had similar composition of organic and mineral phases. All samples in the collection were grouped according to initial structure and amount of organics and processed separately to: 1) study the influence of organic matter content on the changing morphology of the rock under thermal effects; 2) study the effect of initial structure on the primary migration processes for samples with similar organic matter content. An additional experiment was conducted to study the dynamics of changes in the structure of the pore space and prove the validity of our approach. At each stage of heating the morphology of altered rocks was characterized by formation of new pores and channels connecting primary voids. However, it was noted that the samples with a relatively low content of the organic matter had less changes in pore space morphology, in contrast to rocks with a high organic content. Second part of the study also revealed significant differences in resulting pore structures depending on initial structure of the unaltered rocks and connectivity of original

  13. X-ray Crystallography Facility

    NASA Technical Reports Server (NTRS)

    2000-01-01

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

  14. Compton backscattered collmated X-ray source

    DOEpatents

    Ruth, Ronald D.; Huang, Zhirong

    2000-01-01

    A high-intensity, inexpensive and collimated x-ray source for applications such as x-ray lithography is disclosed. An intense pulse from a high power laser, stored in a high-finesse resonator, repetitively collides nearly head-on with and Compton backscatters off a bunched electron beam, having relatively low energy and circulating in a compact storage ring. Both the laser and the electron beams are tightly focused and matched at the interaction region inside the optical resonator. The laser-electron interaction not only gives rise to x-rays at the desired wavelength, but also cools and stabilizes the electrons against intrabeam scattering and Coulomb repulsion with each other in the storage ring. This cooling provides a compact, intense bunch of electrons suitable for many applications. In particular, a sufficient amount of x-rays can be generated by this device to make it an excellent and flexible Compton backscattered x-ray (CBX) source for high throughput x-ray lithography and many other applications.

  15. Compton backscattered collimated x-ray source

    DOEpatents

    Ruth, R.D.; Huang, Z.

    1998-10-20

    A high-intensity, inexpensive and collimated x-ray source is disclosed for applications such as x-ray lithography is disclosed. An intense pulse from a high power laser, stored in a high-finesse resonator, repetitively collides nearly head-on with and Compton backscatters off a bunched electron beam, having relatively low energy and circulating in a compact storage ring. Both the laser and the electron beams are tightly focused and matched at the interaction region inside the optical resonator. The laser-electron interaction not only gives rise to x-rays at the desired wavelength, but also cools and stabilizes the electrons against intrabeam scattering and Coulomb repulsion with each other in the storage ring. This cooling provides a compact, intense bunch of electrons suitable for many applications. In particular, a sufficient amount of x-rays can be generated by this device to make it an excellent and flexible Compton backscattered x-ray (CBX) source for high throughput x-ray lithography and many other applications. 4 figs.

  16. Compton backscattered collimated x-ray source

    DOEpatents

    Ruth, Ronald D.; Huang, Zhirong

    1998-01-01

    A high-intensity, inexpensive and collimated x-ray source for applications such as x-ray lithography is disclosed. An intense pulse from a high power laser, stored in a high-finesse resonator, repetitively collides nearly head-on with and Compton backscatters off a bunched electron beam, having relatively low energy and circulating in a compact storage ring. Both the laser and the electron beams are tightly focused and matched at the interaction region inside the optical resonator. The laser-electron interaction not only gives rise to x-rays at the desired wavelength, but also cools and stabilizes the electrons against intrabeam scattering and Coulomb repulsion with each other in the storage ring. This cooling provides a compact, intense bunch of electrons suitable for many applications. In particular, a sufficient amount of x-rays can be generated by this device to make it an excellent and flexible Compton backscattered x-ray (CBX) source for high throughput x-ray lithography and many other applications.

  17. X-ray nanotomography in a SEM

    NASA Astrophysics Data System (ADS)

    Pauwels, Bart; Liu, Xuan; Sasov, Alexander

    2010-09-01

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

  18. Is low-energy-ion bombardment generated X-ray emission a secondary mutational source to ion-beam-induced genetic mutation?

    NASA Astrophysics Data System (ADS)

    Thongkumkoon, P.; Prakrajang, K.; Thopan, P.; Yaopromsiri, C.; Suwannakachorn, D.; Yu, L. D.

    2013-07-01

    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.

  19. X-ray satellite

    NASA Technical Reports Server (NTRS)

    1985-01-01

    An overview of the second quarter 1985 development of the X-ray satellite project is presented. It is shown that the project is proceeding according to plan and that the projected launch date of September 9, 1987 is on schedule. An overview of the work completed and underway on the systems, subsystems, payload, assembly, ground equipment and interfaces is presented. Problem areas shown include cost increases in the area of focal instrumentation, the star sensor light scattering requirements, and postponements in the data transmission subsystems.

  20. SMM x ray polychromator

    NASA Technical Reports Server (NTRS)

    Saba, J. L. R.

    1993-01-01

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