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Sample records for 2d soft x-ray

  1. 2-D soft x-ray arrays in the EAST.

    PubMed

    Chen, Kaiyun; Xu, Liqing; Hu, Liqun; Duan, Yanmin; Li, Xueqin; Yuan, Yi; Mao, Songtao; Sheng, Xiuli; Zhao, Jinlong

    2016-06-01

    A high spatial and temporal resolution soft x-ray (SXR) imaging diagnostic has been installed in EAST for the study of magnetohydrodynamics activities and core high-Z impurity transport. Up to 122 lines of sight view the poloidal plasma from three directions (two up-down symmetrical horizontal arrays and one vertical array), which renders the diagnostic able to provide detailed tomographic reconstructions under various conditions. Fourier-Bessel method based on flux coordinates was employed for 2-D SXR tomographic reconstruction. Examples of several events measured by SXR diagnostic in EAST are shown, namely the crash patterns of sawtooth, periodical burst of edge localized modes, and the transport of high-Z intrinsic impurities. PMID:27370451

  2. 2-D soft x-ray arrays in the EAST

    NASA Astrophysics Data System (ADS)

    Chen, Kaiyun; Xu, Liqing; Hu, Liqun; Duan, Yanmin; Li, Xueqin; Yuan, Yi; Mao, Songtao; Sheng, Xiuli; Zhao, Jinlong

    2016-06-01

    A high spatial and temporal resolution soft x-ray (SXR) imaging diagnostic has been installed in EAST for the study of magnetohydrodynamics activities and core high-Z impurity transport. Up to 122 lines of sight view the poloidal plasma from three directions (two up-down symmetrical horizontal arrays and one vertical array), which renders the diagnostic able to provide detailed tomographic reconstructions under various conditions. Fourier-Bessel method based on flux coordinates was employed for 2-D SXR tomographic reconstruction. Examples of several events measured by SXR diagnostic in EAST are shown, namely the crash patterns of sawtooth, periodical burst of edge localized modes, and the transport of high-Z intrinsic impurities.

  3. 2D electron temperature diagnostic using soft x-ray imaging technique

    SciTech Connect

    Nishimura, K. Sanpei, A. Tanaka, H.; Ishii, G.; Kodera, R.; Ueba, R.; Himura, H.; Masamune, S.; Ohdachi, S.; Mizuguchi, N.

    2014-03-15

    We have developed a two-dimensional (2D) electron temperature (T{sub e}) diagnostic system for thermal structure studies in a low-aspect-ratio reversed field pinch (RFP). The system consists of a soft x-ray (SXR) camera with two pin holes for two-kinds of absorber foils, combined with a high-speed camera. Two SXR images with almost the same viewing area are formed through different absorber foils on a single micro-channel plate (MCP). A 2D T{sub e} image can then be obtained by calculating the intensity ratio for each element of the images. We have succeeded in distinguishing T{sub e} image in quasi-single helicity (QSH) from that in multi-helicity (MH) RFP states, where the former is characterized by concentrated magnetic fluctuation spectrum and the latter, by broad spectrum of edge magnetic fluctuations.

  4. Characterization of a 2D soft x-ray tomography camera with discrimination in energy bandsa)

    NASA Astrophysics Data System (ADS)

    Romano, A.; Pacella, D.; Mazon, D.; Murtas, F.; Malard, P.; Gabellieri, L.; Tilia, B.; Piergotti, V.; Corradi, G.

    2010-10-01

    A gas detector with a 2D pixel readout is proposed for a future soft x-ray (SXR) tomography with discrimination in energy bands separately per pixel. The detector has three gas electron multiplier foils for the electron amplification and it offers the advantage, compared with the single stage, to be less sensitive to neutrons and gammas. The energy resolution and the detection efficiency of the detector have been accurately studied in the laboratory with continuous SXR spectra produced by an electronic tube and line emissions produced by fluorescence (K, Fe, and Mo) in the range of 3-17 keV. The front-end electronics, working in photon counting mode with a selectable threshold for pulse discrimination, is optimized for high rates. The distribution of the pulse amplitude has been indirectly derived by means of scans of the threshold. Scans in detector gain have also been performed to assess the capability of selecting different energy ranges.

  5. Characterization of a 2D soft x-ray tomography camera with discrimination in energy bands

    SciTech Connect

    Romano, A.; Pacella, D.; Gabellieri, L.; Tilia, B.; Piergotti, V.; Mazon, D.; Malard, P.

    2010-10-15

    A gas detector with a 2D pixel readout is proposed for a future soft x-ray (SXR) tomography with discrimination in energy bands separately per pixel. The detector has three gas electron multiplier foils for the electron amplification and it offers the advantage, compared with the single stage, to be less sensitive to neutrons and gammas. The energy resolution and the detection efficiency of the detector have been accurately studied in the laboratory with continuous SXR spectra produced by an electronic tube and line emissions produced by fluorescence (K, Fe, and Mo) in the range of 3-17 keV. The front-end electronics, working in photon counting mode with a selectable threshold for pulse discrimination, is optimized for high rates. The distribution of the pulse amplitude has been indirectly derived by means of scans of the threshold. Scans in detector gain have also been performed to assess the capability of selecting different energy ranges.

  6. Development of 2D soft X-ray measurement system in the large helical device.

    PubMed

    Takemura, Y; Ohdachi, S; Watanabe, K Y; Du, X D

    2014-11-01

    A fast two-dimensional soft X-ray camera using silicon photo diode array is being developed in order to investigate high frequency MHD instability with high mode number. The advantage of the adopted diode is a large sensor area of 10 mm × 10 mm and small diode capacitance which enable us to measure signals with the short response time. The characteristic of the prototype is summarized as follows: Channel number is 6 × 8 = 48, detection range 1∼10 keV, the spatial resolution 128 mm at the plasma location, and frequency range DC∼100 kHz. Synthetic image of the prototype in the Large Helical Device is estimated by using perturbation model of MHD mode. PMID:25430317

  7. An hybrid detector GEM-ASIC for 2-D soft X-ray imaging for laser produced plasma and pulsed sources

    NASA Astrophysics Data System (ADS)

    Pacella, D.; Claps, G.; De Angelis, R.; Murtas, F.

    2016-03-01

    The following paper presents a new 2-D detector (`GEMpix') in the soft X-ray range, having a wide dynamic range thanks to its intrisic gain, working in charge integration mode to be used for diagnosing laser produced plasma (LPP) or X-ray pulsed sources. It is a gas detector based on the Gas Electron Multiplier (GEM) technology with a quad-medipix chip as read-out electronics. In our prototype, the substitution of semiconductor material with a gas triple-GEM allows several advantages with respect to the detectors commonly used in LPP, as X-ray CCDs and Micro Channel Plates or Image Plates. In these experiments the configuration Time-over-Threshold (ToT) has been used, to measure the total charge released to the gas and collected by each pixel, integrated over the X-ray burst duration. Intensity response and spatial resolution has been measured first in laboratory for calibration, as function of the voltage applied to the GEMs, in single photon regime with energies between 3.7 and 17 keV. Subsequently it has been tested at the ABC laser facility (ENEA, Frascati). In this case, we measured the X-rays produced when the ABC neodymium laser, with pulse of 50 J and 3 ns time width, hits plane targets of aluminum. 2-D images have been acquired by means of a pinhole configuration with magnification 1.5 and 50 μ m of spatial resolution. The results are encouraging regarding the capability of this imaging detector to work in experiments where soft X-ray emissivity varies over many orders of magnitude.

  8. Soft x-ray lasers

    SciTech Connect

    Matthews, D.L.; Rosen, M.D.

    1988-12-01

    One of the elusive dreams of laser physicists has been the development of an x-ray laser. After 25 years of waiting, the x-ray laser has at last entered the scientific scene, although those now in operation are still laboratory prototypes. They produce soft x rays down to about five nanometers. X-ray lasers retain the usual characteristics of their optical counterparts: a very tight beam, spatial and temporal coherence, and extreme brightness. Present x-ray lasers are nearly 100 times brighter that the next most powerful x-ray source in the world: the electron synchrotron. Although Lawrence Livermore National Laboratory (LLNL) is widely known for its hard-x-ray laser program which has potential applications in the Strategic Defense Initiative, the soft x-ray lasers have no direct military applications. These lasers, and the scientific tools that result from their development, may one day have a place in the design and diagnosis of both laser fusion and hard x-ray lasers. The soft x-ray lasers now in operation at the LLNL have shown great promise but are still in the primitive state. Once x-ray lasers become reliable, efficient, and economical, they will have several important applications. Chief among them might be the creation of holograms of microscopic biological structures too small to be investigated with visible light. 5 figs.

  9. Soft x-ray tomoholography

    NASA Astrophysics Data System (ADS)

    Guehrs, Erik; Stadler, Andreas M.; Flewett, Sam; Frömmel, Stefanie; Geilhufe, Jan; Pfau, Bastian; Rander, Torbjörn; Schaffert, Stefan; Büldt, Georg; Eisebitt, Stefan

    2012-01-01

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

  10. Development of a soft-X ray detector for energy resolved 2D imaging by means of a Gas Pixel Detector with highly integrated microelectronics

    SciTech Connect

    Pacella, D.; Pizzicaroli, G.; Romano, A.; Gabellieri, L.; Bellazzini, R.; Brez, A.

    2008-03-12

    Soft-X ray 2-D imaging on ITER is not considered yet. We propose a new approach, based on a gas detector with a gas electron multiplier (GEM) as amplifying structure and with a two-dimensional readout fully integrated with the front end electronics, through an ASIC developed on purpose. The concept has been already tested by means of a prototype, with 128 pixels, carried out in Frascati in collaboration with INFN-Pisa and tested on FTU in 2001 and NSTX in 2002-2004. Thanks to the photon counting mode, it provides 2-D imaging with high time resolution (sub millisecond), high sensitivity and signal to noise ratio. Its capability of energy discrimination allows the acquisition of pictures in X-ray energy bands or to perform a spectral scan in the full energy interval. We propose the realisation of such kind a detector with a readout microchip (ASIC) equipped with 105600 hexagonal pixels arranged at 70 {mu}m pitch in a 300x352 honeycomb matrix, corresponding to an active area of 2.1x2.1 cm{sup 2}, with a pixel density of 240 pixels/ mm{sup 2}. Each pixel is connected to a charge sensitive amplifier followed by a discriminator of pulse amplitude and counter. The chip integrates more than 16.5 million transistors and it is subdivided in 64 identical clusters, to be read independently each other. An important part of the work will be also the design of the whole detector to fulfil all the constraints and requirements as plasma diagnostic in a tokamak machine. Since the detector has high and controllable intrinsic gain, it works well even at very low photon energy, ranging from 0.2 keV to 10 keV (X-VUV region). This range appears therefore particularly suitable for ITER to monitor the outer part of the plasma. In particular pedestal physics, edge modes, localization and effects of additional heating, boundary plasma control etc. The capability of this proposed detector to work in this energy range is further valuable because solid state detectors are not favorite at low

  11. Soft x-ray interferometry

    SciTech Connect

    Not Available

    1993-09-01

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

  12. Applications of soft x-ray lasers

    SciTech Connect

    Skinner, C.H.

    1993-08-01

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

  13. Soft x-ray polarimeter laboratory tests

    NASA Astrophysics Data System (ADS)

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

    2010-07-01

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

  14. Polars - soft X-ray emitters?

    NASA Astrophysics Data System (ADS)

    Schwope, Axel

    2010-10-01

    The defining criterion of polars (AM Herculis stars) was their prominent soft X-ray emission, which led to numerous discoveries with the EINSTEIN, EXOSAT, ROSAT and EUVE satellites. XMM-Newton observations of those X-ray selected polars and genuine discoveries of new polar systems reveal growing evidence that the prevailence or even the existence of a soft X-ray component may be rather the exception than the rule. In the last decade polars were discovered in optical surveys like the SDSS and the CSS. Here we propose XMM-Newton observations of 5 optically selected polars to search for soft X-ray spectral components, answer the question why they escaped detection in past X-ray surveys and shed new light on the intrinsic energy distribution of polars.

  15. Polars - soft X-ray emitters?

    NASA Astrophysics Data System (ADS)

    Schwope, Axel

    2011-10-01

    The defining criterion of polars (AM Herculis stars) was their prominent soft X-ray emission, which led to numerous discoveries with the EINSTEIN, EXOSAT, ROSAT and EUVE satellites. XMM-Newton discovered polars however and new polar systems from optical surveys (SDSS, CSS) reveal growing evidence that the prevalence or even the existence of a soft X-ray component may be rather the exception than the rule. Here we propose XMM-Newton observations of 5 optically identified polars to search for soft X-ray spectral components, answer the question why they escaped detection in past X-ray surveys and shed new light on the intrinsic energy distribution and accretion energy release of polars.

  16. Soft x-ray tomography on TFTR

    SciTech Connect

    Kuo-Petravic, G.

    1988-12-01

    The tomographic method used for deriving soft x-ray local emissivities on TFTR, using one horizontal array of 60 soft x-ray detectors, is described. This method, which is based on inversion of Fourier components and subsequent reconstruction, has been applied to the study of a sawtooth crash. A flattening in the soft x-ray profile, which we interpret as an m = 1 island, is clearly visible during the precursor phase and its location and width correlate well with those from electron temperature profiles reconstructed from electron cyclotron emission measurement. The limitations of the Fourier method, due notably to the aperiodic nature of the signals in the fast crash phase and the difficulty of obtaining accurately the higher Fourier harmonics, are discussed. 9 refs., 13 figs.

  17. Resonant Soft X-ray Scattering for Soft Materials

    NASA Astrophysics Data System (ADS)

    Wang, Cheng; Young, Athony; Hexemer, Alexander; Padmore, Howard

    2015-03-01

    Over the past a few years, we have developed Resonant Soft X-ray Scattering (RSoXS) and constructed the first dedicated resonant soft x-ray scattering beamline at the Advanced Light Source, LBNL. RSoXS combines soft x-ray spectroscopy with x-ray scattering thus offers statistical information for 3D chemical morphology over a large length scale range from nanometers to micrometers. Its unique chemical sensitivity, large accessible size scale, molecular bond orientation sensitivity with polarized x-rays and high coherence have shown great potential for chemical/morphological structure characterization for many classes of materials. Some recent development of in-situ soft x-ray scattering with in-vacuum sample environment will be discussed. In order to study sciences in naturally occurring conditions, we need to overcome the sample limitations set by the low penetration depth of soft x-rays and requirement of high vacuum. Adapting to the evolving environmental cell designs utilized increasingly in the Electron Microscopy community, customized designed liquid/gas environmental cells will enable soft x-ray scattering experiments on biological, electro-chemical, self-assembly, and hierarchical functional systems in both static and dynamic fashion. Recent RSoXS results on organic electronics, block copolymer thin films, and membrane structure will be presented.

  18. European XFEL: Soft X-Ray instrumentation

    SciTech Connect

    Molodtsov, S. L.

    2011-12-15

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

  19. 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.

  20. 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.

  1. Soft x-ray laser microscope

    SciTech Connect

    Suckewer, P.I.

    1990-10-01

    The program consisted of two phases (Phase I and Phase II). The goal of the Phase I (first year program) was to design and construct the Soft X-ray Laser Contact Microscope. Such microscope was constructed and adapted to PPL's 18.2nm soft X-ray Laser (SXL), which in turn was modified and prepared for microscopy experiments. Investigation of the photoresist response to 18.2nm laser radiation and transmissivity of 0.1m thick silicion-nitride (Si[sub 3]N[sub 4]) windows were important initial works. The goal of the first year of Phase II was to construct X-ray contact microscope in combination with existing optical phase microscope, already used by biologists. In the second year of Phase II study of dehydrated Horeseshoe Crab and Hela cancer cells were performed with COXRALM. Also during Phase II, the Imaging X-Ray Laser Microscope (IXRALM) was designed and constructed. This paper describes the development of each of the microscopes and their application for research.

  2. Soft x-ray laser microscopy

    SciTech Connect

    DiCicco, D.; Meixler, L.; Skinner, C.H.; Suckewer, S.; Hirschberg, J.; Kohen, E.

    1987-12-31

    Microscopes based on soft X-ray lasers possess unique advantages in bridging the gap between high resolution electron microscopy of dehydrated, stained cells and light microscopy at comparatively low resolution of unaltered live cells. The high brightness and short pulse duration of soft X-ray lasers make them ideal for flash imaging of live specimens. The Princeton soft X-ray laser is based on a magnetically confined laser produced carbon plasma. Radiation cooling after the laser pulse produces rapid recombination which produces a population inversion and high gain. A full account is given in a companion paper in this volume. The important characteristics of the laser beam produced by this device are 1 to 3 mJ of 18.2 nm radiation in a 10 to 30 nsec pulse with a divergence of 5 mrad. The 18.2 nm wavelength, while outside the water window, does provide a factor of 3 difference in absorption coefficients between oxygen and carbon.

  3. Soft x-ray laser microscopy

    SciTech Connect

    DiCicco, D. ); Meixler, L.; Skinner, C.H.; Suckewer, S. . Plasma Physics Lab.); Hirschberg, J.; Kohen, E. . Dept. of Physics)

    1987-01-01

    Microscopes based on soft X-ray lasers possess unique advantages in bridging the gap between high resolution electron microscopy of dehydrated, stained cells and light microscopy at comparatively low resolution of unaltered live cells. The high brightness and short pulse duration of soft X-ray lasers make them ideal for flash imaging of live specimens. The Princeton soft X-ray laser is based on a magnetically confined laser produced carbon plasma. Radiation cooling after the laser pulse produces rapid recombination which produces a population inversion and high gain. A full account is given in a companion paper in this volume. The important characteristics of the laser beam produced by this device are 1 to 3 mJ of 18.2 nm radiation in a 10 to 30 nsec pulse with a divergence of 5 mrad. The 18.2 nm wavelength, while outside the water window, does provide a factor of 3 difference in absorption coefficients between oxygen and carbon.

  4. Laboratory cryo soft X-ray microscopy.

    PubMed

    Hertz, H M; von Hofsten, O; Bertilson, M; Vogt, U; Holmberg, A; Reinspach, J; Martz, D; Selin, M; Christakou, A E; Jerlström-Hultqvist, J; Svärd, S

    2012-02-01

    Lens-based water-window X-ray microscopy allows two- and three-dimensional (2D and 3D) imaging of intact unstained cells in their near-native state with unprecedented contrast and resolution. Cryofixation is essential to avoid radiation damage to the sample. Present cryo X-ray microscopes rely on synchrotron radiation sources, thereby limiting the accessibility for a wider community of biologists. In the present paper we demonstrate water-window cryo X-ray microscopy with a laboratory-source-based arrangement. The microscope relies on a λ=2.48-nm liquid-jet high-brightness laser-plasma source, normal-incidence multilayer condenser optics, 30-nm zone-plate optics, and a cryo sample chamber. We demonstrate 2D imaging of test patterns, and intact unstained yeast, protozoan parasites and mammalian cells. Overview 3D information is obtained by stereo imaging while complete 3D microscopy is provided by full tomographic reconstruction. The laboratory microscope image quality approaches that of the synchrotron microscopes, but with longer exposure times. The experimental image quality is analyzed from a numerical wave-propagation model of the imaging system and a path to reach synchrotron-like exposure times in laboratory microscopy is outlined. PMID:22119891

  5. X-ray microscopy of soft and hard human tissues

    NASA Astrophysics Data System (ADS)

    Müller, Bert; Schulz, Georg; Deyhle, Hans; Stalder, Anja K.; Ilgenstein, Bernd; Holme, Margaret N.; Weitkamp, Timm; Beckmann, Felix; Hieber, Simone E.

    2016-01-01

    The simultaneous post mortem visualization of soft and hard tissues using absorption-based CT remains a challenge. If the photon energy is optimized for the visualization of hard tissue, the surrounding soft tissue components are almost X-ray transparent. Therefore, the combination with other modalities such as phase-contrast CT, magnetic resonance microscopy, and histology is essential to detect the anatomical features. The combination of the 2D and 3D data sets using sophisticated segmentation and registration tools allows for conclusions about otherwise inaccessible anatomical features essential for improved patient treatments.

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

    NASA Technical Reports Server (NTRS)

    Schwartz, Daniel

    1998-01-01

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

  7. Soft x-ray transmission gratings

    SciTech Connect

    Arakawa, E. T.; Caldwell, P. J.; Williams, M. W.

    1980-01-01

    A technique was developed for producing transmission diffraction gratings suitable for use in the soft x-ray region. Thin self-supporting films of a transparent material are overlaid with several thousand opaque metallic strips per mm. Gratings with 2100, 2400, and 5600 1/mm have been produced and tested. Representative spectra over the wavelength range from 17.2 to 40.0 nm are given for a grating consisting of a 120-nm-thick Al support layer overlaid with 2400, 34-nm-thick, Ag strips/mm. The absolute transmittance is approx. 13% at 30 nm, and the efficiency in the first order is approx. 16%. The observed resolution of approx. 2A is acceptable for many of the potential applications. These gratings have several advantages over the two presently available alternatives in the soft x-ray region (i.e., reflection gratings used at grazing incidence and free-standing metallic wire transmission gratings). Fabrication is relatively quick, simple, and cheap. The support layer can also serve as a filter and help conduct excessive heat away. Higher line densities and hence higher resolutions are possible, and when used at normal incidence the spectra are aberration free. Suitable materials, component thicknesses, and line densities can be chosen to produce a grating of optimum characteristics for a particular application.

  8. Soft X-ray measurements in magnetic fusion plasma physics

    NASA Astrophysics Data System (ADS)

    Botrugno, A.; Gabellieri, L.; Mazon, D.; Pacella, D.; Romano, A.

    2010-11-01

    Soft X-ray diagnostic systems and their successful application in the field of magnetic fusion plasma physics are discussed. Radiation with wavelength in the region of Soft X-Ray (1-30 keV) is largely produced by high temperature plasmas, carrying important information on many processes during a plasma discharge. Soft X-ray diagnostics are largely used in various fusion devices all over the world. These diagnostic systems are able to obtain information on electron temperature, electron density, impurity transport, Magneto Hydro Dynamic instabilities. We will discuss the SXR diagnostic installed on FTU in Frascati (Italy) and on Tore Supra in Cadarache (France), with special emphasis on diagnostic performances. Moreover, we will discuss the two different inversion methods for tomographic reconstruction used in Frascati and in Cadarache, the first one is relied on a guessed topology of iso-emissivity surfaces, the second one on regularization techniques, like minimum Fisher or maximum entropy. Finally, a new and very fast 2D imaging system with energy discrimination and high time resolution will be summarized as an alternative approach of SXR detection system.

  9. The PERCIVAL soft X-ray imager

    NASA Astrophysics Data System (ADS)

    Wunderer, C. B.; Marras, A.; Bayer, M.; Correa, J.; Göttlicher, P.; Lange, S.; Shevyakov, I.; Smoljanin, S.; Tennert, M.; Viti, M.; Xia, Q.; Zimmer, M.; Das, D.; Guerrini, N.; Marsh, B.; Sedgwick, I.; Turchetta, R.; Cautero, G.; Gianoncelli, A.; Giuressi, D.; Menk, R.; Stebel, L.; Yousef, H.; Marchal, J.; Rees, N.; Tartoni, N.; Graafsma, H.

    2015-02-01

    With the increased brilliance of state-of-the-art Synchrotron radiation sources and the advent of Free Electron Lasers enabling revolutionary science on atomic length and time scales with EUV to X-ray photons comes an urgent need for suitable photon imaging detectors. Requirements include high frame rates, very large dynamic range, single-photon counting capability with low probability of false positives, and (multi)-megapixels. PERCIVAL (``Pixelated Energy Resolving CMOS Imager, Versatile And Large'') is currently being developed by a collaboration of DESY, RAL, Elettra, DLS and Pohang to address this need for the soft X-ray regime. PERCIVAL is a monolithic active pixel sensor (MAPS), i.e. based on CMOS technology. It will be back-thinned to access its primary energy range of 250 eV to 1 keV with target efficiencies above 90%. According to its preliminary specifications, the roughly 10 × 10 cm2, 3.5k × 3.7k monolithic ``PERCIVAL13M'' sensor will operate at frame rates up to 120 Hz (commensurate with most FELs) and use multiple gains within its 27 μm pixels to measure 1 to ~ 105 (500 eV) simultaneously-arriving photons. A smaller ``PERCIVAL2M'' with ~ 1.4k × 1.5k pixels is also planned. Currently, small-scale back-illuminated prototype systems (160 × 210 pixels of 25 μm pitch) are undergoing detailed testing with X-rays and optical photons. In March 2014, a prototype sensor was tested at 350 eV-2 keV at Elettra's TwinMic beamline. The data recorded include diffraction patterns at 350 eV and 400 eV, knife edge and sub-pixel pinhole illuminations, and comparisons of different pixel types. Another prototype chip will be submitted in fall 2014, first larger sensors could be in hand in late 2015.

  10. Technology development for soft X-ray spectroscopy

    NASA Astrophysics Data System (ADS)

    Törmä, P. T.; Sipilä, H. J.; Koskinen, T.; Mattila, M.

    2016-05-01

    X-ray spectroscopy instruments lose part of their performance due to the lack of suitable components for soft X-ray region below 1 keV. Therefore, in the analysis of low atomic number elements including lithium, beryllium, boron and carbon instrument sensitivity is often limited. In this work we describe how the performance of the spectroscopy of soft X-rays is significantly improved when all devices integrated in the spectroscopic instrument are suitable for both soft and hard X-rays. This concept is based on utilizing ultra-thin SiN X-ray windows with proven performance not only as a detector window but also as an X-ray source window. By including a soft-X-ray-sensitive silicon drift detector with efficient surface charge collection in this concept the sensitivity and performance of the instrument is significantly increased.

  11. Soft X-Ray Tomography in HSX

    NASA Astrophysics Data System (ADS)

    Sakaguchi, V.; Almagri, A. F.; Anderson, D. T.; Anderson, F. S. B.; Likin, K.

    2003-10-01

    Under certain discharge conditions, HSX plasmas exhibit a sudden loss of stored energy followed by fluctuations of the order of few kHz in both the stored energy and the soft x-ray (SXR) signals. These are measured by a diamagnetic loop and a set of PIPS detectors respectively. To help understand the origin of these crashes and the nature of the oscillations, as well as to measure basic plasma properties such as position and shape, a SXR tomography system is under development in HSX. A single array of 20 silicon p-n junction photodiodes is installed on the device and, in the near future, the diagnostic system will be expanded to several arrays in order to obtain tomographic reconstructions of the SXR emission. Initial SXR and stored energy measurements during these crashing discharges as well as the results of the one-array reconstruction will be presented. Implementation details of the complete tomographic system will be shown as well.

  12. Demonstration of ultra high resolution soft x-ray tomography

    NASA Astrophysics Data System (ADS)

    Haddad, W. S.; McNulty, I.; Trebes, J. E.; Anderson, E. H.; Yang, L.; Brase, J. M.

    1995-05-01

    Ultra high resolution three dimensional images of a microscopic test object were made with soft x-rays using a scanning transmission x-ray microscope. The test object consisted of two different patterns of gold bars on silicon nitride windows which were separated by ˜ 5μm. Depth resolution comparable to the transverse resolution was achieved by recording nine 2-D images of the object at angles between -50 to +55 degrees with respect to the beam axis. The projections were then combined tomographically to form a 3-D image using an algebraic reconstruction technique (ART) algorithm. We observed a transverse resolution of ˜1000 Å. Artifacts in the reconstruction limited the overall depth resolution to ˜6000 Å, however some features were clearly reconstructed with a depth resolution of ˜1000 Å.

  13. Tunable Soft X-Ray Oscillators

    SciTech Connect

    Wurtele, Jonathan; Gandhi, Punut; Gu, X-W; Fawley, William M; Reinsch, Matthia; Penn, Gregory; Kim, K-J; Lindberg, Ryan; Zholents, Alexander

    2010-09-17

    A concept for a tunable soft x-ray free electron laser (FEL) photon source is presented and studied numerically. The concept is based on echo-enabled harmonic generation (EEHG), wherein two modulator-chicane sections impose high harmonic structure with much greater efficacy as compared to conventional high harmonic FELs that use only one modulator-chicane section. The idea proposed here is to replace the external laser power sources in the EEHG modulators with FEL oscillators, and to combine the bunching of the beam with the production of radiation. Tunability is accomplished by adjusting the magnetic chicanes while the two oscillators remain at a fixed frequency. This scheme eliminates the need to develop coherent sources with the requisite power, pulse length, and stability requirements by exploiting the MHz bunch repetition rates of FEL continuous wave (CW) sources driven by superconducting (SC) linacs. We present time-dependent GINGER simulation results for an EEHG scheme with an oscillator modulator at 43 nm employing 50percent reflective dielectric mirrors and a second modulator employing an external, 215-nm drive laser. Peak output of order 300 MW is obtained at 2.7 nm, corresponding to the 80th harmonic of 215 nm. An alternative single-cavity echo-oscillator scheme based on a 13.4 nm oscillator is investigated with time-independent simulations that a 180-MW peak power at final wavelength of 1.12 nm. Three alternate configurations that use separate bunches to produce the radiation for EEHG microbunching are also presented. Our results show that oscillator-based soft x-ray FELs driven by CWSC linacs are extremely attractive because of their potential to produce tunable radiation at high average power together with excellent longitudinal coherence and narrow spectral bandwidth.

  14. Effects of Galactic absorption on soft X-ray surveys

    NASA Technical Reports Server (NTRS)

    Zamorani, G.; Gioia, I. M.; Maccacaro, T.; Wolter, A.

    1988-01-01

    A bias in the spectral distribution of X-ray sources detected in X-ray surveys is discussed which is due to the combination of the intrinsic characteristics of X-ray telescopes and the effects of low-energy photoelectric absorption within the Galaxy. A statistical method for obtaining information on the average spectrum of X-ray sources detected in well-defined surveys is presented. This method can be applied to surveys performed with X-ray telescopes working at relatively soft X-ray energies, such as Einstein, Exosat, and Rosat.

  15. A soft X-ray image of the moon

    NASA Technical Reports Server (NTRS)

    Schmitt, J. H. M. M.; Aschenbach, B.; Hasinger, G.; Pfeffermann, E.; Snowden, S. L.

    1991-01-01

    A soft X-ray image of the moon obtained by the Roentgen Observatory Satellite ROSAT clearly shows a sunlit crescent, demonstrating that the moon's X-ray luminosity arises from backscattering of solar X-rays. The moon's optically dark side is also X-ray dark, and casts a distinct shadow on the diffuse cosmic X-ray background. Unexpectedly, the dark side seems to emit X-rays at a level about one percent of that of the bright side; this emission very probably results from energetic solar-wind electrons striking the moon's surface.

  16. Dante Soft X-ray Power Diagnostic for NIF

    SciTech Connect

    Dewald, E; Campbell, K; Turner, R; Holder, J; Landen, O; Glenzer, S; Kauffman, R; Suter, L; Landon, M; Rhodes, M; Lee, D

    2004-04-15

    Soft x-ray power diagnostics are essential for measuring spectrally resolved the total x-ray flux, radiation temperature, conversion efficiency and albedo that are important quantities for the energetics of indirect drive hohlraums. At the Nova or Omega Laser Facilities, these measurements are performed mainly with Dante, but also with DMX and photo-conductive detectors (PCD's). The Dante broadband spectrometer is a collection of absolute calibrated vacuum x-ray diodes, thin filters and x-ray mirrors used to measure the soft x-ray emission for photon energies above 50 eV.

  17. Soft X-Ray Emissions from Planets and Moons

    NASA Technical Reports Server (NTRS)

    Bhardwaj, A.; Gladstone, G. R.; Elsner, R. F.; Waite, J. H., Jr.; Grodent, D.; Lewis, W. S.; Crary, F. J.; Weisskopf, M. C.; Howell, R. R.; Johnson, R. E.; Six, N. Frank (Technical Monitor)

    2002-01-01

    The soft x-ray energy band (less than 4 keV) is an important spectral regime for planetary remote sensing, as a wide variety of solar system objects are now known to shine at these wavelengths. These include Earth, Jupiter, comets, moons, Venus, and the Sun. Earth and Jupiter, as magnetic planets, are observed to emanate strong x-ray emissions from their auroral (polar) regions, thus providing vital information on the nature of precipitating particles and their energization processes in planetary magnetospheres. X rays from low latitudes have also been observed on these planets, resulting largely from atmospheric scattering and fluorescence of solar x-rays. Cometary x-rays are now a well established phenomena, more than a dozen comets have been observed at soft x-ray energies, with the accepted production mechanism being charge-exchange between heavy solar wind ions and cometary neutrals. Also, Lunar x-rays have been observed and are thought to be produced by scattering and fluorescence of solar x-rays from the Moon's surface. With the advent of sophisticated x-ray observatories, e.g., Chandra and XMM-Newton, the field of planetary x-ray astronomy is advancing at a much faster pace. The Chandra X-ray Observatory (CXO) has recently captured soft x-rays from Venus. Venusian x-rays are most likely produced through fluorescence of solar x-rays by C and O atoms in the upper atmosphere. Very recently, using CXO we have discovered soft x-rays from the moons of Jupiter-Io, Europa, and probably Ganymede. The plausible source of the x-rays from the Galilean satellites is bombardment of their surfaces by energetic (greater than 10 KeV) ions from the inner magnetosphere of Jupiter. The Io plasma Torus (IPT) is also discovered by CXO to be a source of soft x-rays by CXO have revealed a mysterious pulsating (period approx. 45 minutes) x-ray hot spot is fixed in magnetic latitude and longitude and is magnetically connected to a region in the outer magnetosphere of Jupiter. These

  18. The Origin of Soft X-rays in DQ Herculis

    NASA Technical Reports Server (NTRS)

    White, Nicholas E. (Technical Monitor); Mukai, K.; Still, M.; Ringwald, F. A.

    2002-01-01

    DQ Herculis (Nova Herculis 1934) is a deeply eclipsing cataclysmic variable containing a magnetic white dwarf primary. The accretion disk is thought to block our line of sight to the white dwarf at all orbital phases due to its extreme inclination angle. Nevertheless, soft X-rays were detected from DQ Her with ROSAT PSPC. To probe the origin of these soft X-rays, we have performed Chandra ACIS observations. We confirm that DQ Her is an X-ray source. The bulk of the X-rays are from a point-like source and exhibit a shallow partial eclipse. We interpret this as due to scattering of the unseen central X-ray source, probably in an accretion disk wind. At the same time, we detect weak extended X-ray features around DQ Her, which we interpret as an X-ray emitting knot in the nova shell.

  19. The hard X-ray perspective on the soft X-ray excess

    SciTech Connect

    Vasudevan, Ranjan V.; Mushotzky, Richard F.; Reynolds, Christopher S.; Lohfink, Anne M.; Zoghbi, Abderahmen; Fabian, Andrew C.; Gallo, Luigi C.; Walton, Dominic

    2014-04-10

    The X-ray spectra of many active galactic nuclei exhibit a 'soft excess' below 1 keV, whose physical origin remains unclear. Diverse models have been suggested to account for it, including ionized reflection of X-rays from the inner part of the accretion disk, ionized winds/absorbers, and Comptonization. The ionized reflection model suggests a natural link between the prominence of the soft excess and the Compton reflection hump strength above 10 keV, but it has not been clear what hard X-ray signatures, if any, are expected from the other soft X-ray candidate models. Additionally, it has not been possible up until recently to obtain high-quality simultaneous measurements of both soft and hard X-ray emission necessary to distinguish these models but upcoming joint XMM-NuSTAR programs provide precisely this opportunity. In this paper, we present an extensive analysis of simulations of XMM-NuSTAR observations, using two candidate soft excess models as inputs, to determine whether such campaigns can disambiguate between them by using hard and soft X-ray observations in tandem. The simulated spectra are fit with the simplest 'observer's model' of a blackbody and neutral reflection to characterize the strength of the soft and hard excesses. A plot of the strength of the hard excess against the soft excess strength provides a diagnostic plot which allows the soft excess production mechanism to be determined in individual sources and samples using current state-of-the-art and next generation hard X-ray enabled observatories. This approach can be straightforwardly extended to other candidate models for the soft excess.

  20. Stellar contribution to the galactic soft x-ray background

    SciTech Connect

    Rosner, R.; Avni, Y.; Bookbinder, J. R.,Giacconi; Golub, L.; Harnden, F.R. Jr.; Maxson, C.W.; Topka, K.; Vaiana, G.S.

    1981-10-01

    We construct log N-log S relations for stars based on medium x-ray luminosities for dF, dG, and dK stars previously reported for the Einstein Observatory/Center for Astrophysics stellar survey and on a detailed x-ray luminosity function derived here for dM stars, and investigate the stellar contribution to the diffuse soft x-ray background. The principal results are that stars provide approx.20% of the soft x-ray background in the 0.28--1.0 keV passband and therefore contribute significantly to the soft x-ray background in this energy range (with dM stars constituting the dominant contributing class), and that the stellar contribution to the diffuse x-ray background in the 0.15--0.28 keV passband is < or approx. =3%.

  1. Moon: lunar albedo for soft x-rays

    NASA Astrophysics Data System (ADS)

    Ibadov, Subhon

    2016-07-01

    Albedo of the Moon for soft X-rays (0.1-2 keV photons) is determined on the basis of the X-ray luminosity of the Moon detected and measured for the first time by orbital space telescope ROSAT in 1990. It is found that the lunar albedo for the solar soft X-rays is less than the lunar visual region albedo almost thousand times. The data allow to estimate more correctly X-ray luminosity of dusty comets like Hyakutake C/1996 B2 and Hale-Bopp C/1995 O1 due to scattering of solar soft X-rays and to reveal thus the dominant mechanism for production of X-rays in dusty comets.

  2. Phase Resolved X-ray Spectral Analysis of Soft IPs

    NASA Astrophysics Data System (ADS)

    Pekon, Yakup

    2016-07-01

    As a subclass of Cataclysmic Variables, Intermediate Polars (IPs) are magnetic systems which mainly show hard X-ray emission. However, there have been an increasing number of systems that also show a soft emission component arising from reprocessed X-rays from the white dwarf limbs. Due to their relatively short periods, they pose as good canditates to perform phase resolved analysis. In this work, X-ray phase resolved spectral analysis of selected IPs with soft X-ray emission components (such as PQ Gem, V2069 Cyg etc.) over the orbital and/or spin periods will be presented. The analyses will help a better understanding of the complex absorption mechanisms and the nature of the soft X-ray emissions in soft IPs.

  3. Multilayers for EUV, soft x-ray and x-ray optics

    NASA Astrophysics Data System (ADS)

    Wang, Zhanshan; Huang, Qiushi; Zhang, Zhong

    2016-02-01

    Driven by the requirements in synchrotron radiation applications, astronomical observation, and dense plasma diagnostics, the EUV, soft X-rays and X-rays multilayer optics have been tremendously developed. Based on the LAMP project for soft X-ray polarimetry, Co/C and Cr/C multilayers have been fabricated and characterized. Both Co/C and Cr/C multilayers reveal good optical performance working at 250 eV. Pd/Y multilayers have been successfully fabricated using reactive sputtering with nitrogen working at around 9.4 nm. EUV normal incidence Schwarzschild and soft X-ray grazing incidence KB microscopes were developed for ICF plasma diagnostics. This paper covers the outline of the multilayer optics and the current status in our lab.

  4. Modeled soft X-ray solar irradiances

    NASA Technical Reports Server (NTRS)

    Tobiska, W. Kent

    1994-01-01

    Solar soft X-rays have historically been inaccurately modeled in both relative variations and absolute magnitudes by empirical solar extreme ultraviolet (EUV) irradiance models. This is a result of the use of a limited number of rocket data sets which were primarily associated with the calibration of the AE-E satellite EUV data set. In this work, the EUV91 solar EUV irradiance model has been upgraded to improve the accuracy of the 3.0 to 5.0 nm relative irradiance variations. The absolute magnitude estimate of the flux in this wavelength range has also been revised upwards. The upgrade was accomplished by first digitizing the SOLRAD 11 satellite 4.4 to 6.0 nm measured energy flux data set, then extracting and extrapolating a derived 3.0 to 5.0 nm photon flux from these data, and finally by performing a correlation between these derived data and the daily and 81-day mean 10.7 cm radio flux emission using a multiple linear regression technique. A correlation coefficient of greater than 0.9 was obtained between the dependent and independent data sets. The derived and modeled 3.0 to 5.0 nm flux varies by more than an order of magnitude over a solar cycle, ranging from a flux below 1 x 10(exp 8) to a flux greater than 1 x 10(exp 9) photons per sq cm per sec. Solar rotational (27-day) variations in the flux magnitude are a factor of 2. The derived and modeled irradiance absolute values are an order of magnitude greater than previous values from rocket data sets related to the calibration of the AE-E satellite.

  5. Resonant magnetic scattering of polarized soft x rays

    SciTech Connect

    Sacchi, M.; Hague, C.F.; Gullikson, E.M.; Underwood, J.

    1997-04-01

    Magnetic effects on X-ray scattering (Bragg diffraction, specular reflectivity or diffuse scattering) are a well known phenomenon, and they also represent a powerful tool for investigating magnetic materials since it was shown that they are strongly enhanced when the photon energy is tuned across an absorption edge (resonant process). The resonant enhancement of the magnetic scattering has mainly been investigated at high photon energies, in order to match the Bragg law for the typical lattice spacings of crystals. In the soft X-ray range, even larger effects are expected, working for instance at the 2p edges of transition metals of the first row or at the 3d edges of rare earths (300-1500 eV), but the corresponding long wavelengths prevent the use of single crystals. Two approaches have been recently adopted in this energy range: (i) the study of the Bragg diffraction from artificial structures of appropriate 2d spacing; (ii) the analysis of the specular reflectivity, which contains analogous information but has no constraints related to the lattice spacing. Both approaches have their own specific advantages: for instance, working under Bragg conditions provides information about the (magnetic) periodicity in ordered structures, while resonant reflectivity can easily be related to electronic properties and absorption spectra. An important aspect common to all the resonant X-ray scattering techniques is the element selectivity inherent to the fact of working at a specific absorption edge: under these conditions, X-ray scattering becomes in fact a spectroscopy. Results are presented for films of iron and cobalt.

  6. 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.

  7. Development of small scale soft x-ray lasers

    SciTech Connect

    Kim, D.; Suckewer, S. . Plasma Physics Lab. Princeton Univ., NJ . Dept. of Mechanical and Aerospace Engineering); Skinner, C.H.; Voorhees, D. . Plasma Physics Lab.)

    1991-05-01

    At present rapid progress is being made in the application of soft x-ray lasers to fields such as microscopy and microlithography. A critical factor in the range of suitable applications is the scale and hence cost of the soft x-ray lasers. At Princeton, gain at 183{angstrom} has been obtained with relatively low pump laser energies (as low as 6J) in a portable'' small-scale soft x-ray laser system. We will also discuss aspects of data interpretation and pitfalls to be avoided in measurements of gain in such systems. 14 refs., 7 figs.

  8. Soft-x-ray spectroscopy study of nanoscale materials

    SciTech Connect

    Guo, J.-H.

    2005-07-30

    The ability to control the particle size and morphology of nanoparticles is of crucial importance nowadays both from a fundamental and industrial point of view considering the tremendous amount of high-tech applications. Controlling the crystallographic structure and the arrangement of atoms along the surface of nanostructured material will determine most of its physical properties. In general, electronic structure ultimately determines the properties of matter. Soft X-ray spectroscopy has some basic features that are important to consider. X-ray is originating from an electronic transition between a localized core state and a valence state. As a core state is involved, elemental selectivity is obtained because the core levels of different elements are well separated in energy, meaning that the involvement of the inner level makes this probe localized to one specific atomic site around which the electronic structure is reflected as a partial density-of-states contribution. The participation of valence electrons gives the method chemical state sensitivity and further, the dipole nature of the transitions gives particular symmetry information. The new generation synchrotron radiation sources producing intensive tunable monochromatized soft X-ray beams have opened up new possibilities for soft X-ray spectroscopy. The introduction of selectively excited soft X-ray emission has opened a new field of study by disclosing many new possibilities of soft X-ray resonant inelastic scattering. In this paper, some recent findings regarding soft X-ray absorption and emission studies of various nanostructured systems are presented.

  9. Hard X-Ray, Soft X-Ray, and EUV Studies of Solar Eruptions

    NASA Technical Reports Server (NTRS)

    Sterling, Alphonse C.; Wagner, William (Technical Monitor)

    2003-01-01

    Document study the hard X-ray (HXR), soft X-ray (SXR) ,EUV, and magnetic nature of solar eruptions, with the objective of elucidating the physics of the eruption process. In particular, it was examine the viability of two specific eruption mechanisms, detailed in our proposal. These mechanisms are the "breakout model", and the "tether cutting model". During the second year, it was a significant progress in the goals to Data Sets Utilized. In the publications during this second year of the grant period, the data was used from the E W Imaging Telescope (EIT) and the Michelson Doppler Imager (MDI) instruments on SOHO, and from the Soft X-ray Telescope (SXT), Hard X-ray Telescope (HXT), and the Bragg Crystal Spectrometer (BCS) on Yooh.

  10. Soft-X-Ray Prefilter for Hot, Bright Objects

    NASA Technical Reports Server (NTRS)

    Davis, J. M.; Ortendahl, J. A.

    1985-01-01

    Prefilters consisting of beryllium foil supported on conductive silver mesh transmit soft x-rays but are nearly opaque to visible and infrared light. New Be/AG filters protect imaging X-ray detectors from damage by visible and longer wavelength radiation when viewing such hot, bright emitters as Sun or possibly certain industrial processes.

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

    PubMed

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

    2015-07-01

    The HERMES beamline (High Efficiency and Resolution beamline dedicated to X-ray Microscopy and Electron Spectroscopy), built at Synchrotron SOLEIL (Saint-Auban, France), is dedicated to soft X-ray microscopy. The beamline combines two complementary microscopy methods: XPEEM (X-ray Photo Emitted Electron Microscopy) and STXM (Scanning Transmission X-ray Microscopy) with an aim to reach spatial resolution below 20 nm and to fully exploit the local spectroscopic capabilities of the two microscopes. The availability of the two methods within the same beamline enables the users to select the appropriate approach to study their specific case in terms of sample environment, spectroscopy methods, probing depth etc. In this paper a general description of the beamline and its design are presented. The performance and specifications of the beamline will be reviewed in detail. Moreover, the article is aiming to demonstrate how the beamline performances have been specifically optimized to fulfill the specific requirements of a soft X-ray microscopy beamline in terms of flux, resolution, beam size etc. Special attention has been dedicated to overcome some limiting and hindering problems that are usually encountered on soft X-ray beamlines such as carbon contamination, thermal stability and spectral purity. PMID:26134801

  12. First Terrestrial Soft X-ray Auroral Observation by the Chandra X-Ray Observatory

    NASA Technical Reports Server (NTRS)

    Bhardwaj, Anil; Elsner, Ronald F.; Gladstone, G. Randall; Ostegaard, Nikolai; Waite, J. Hunter, Jr.; Cravens, Thomas E.; Chang, Shen-Wu; Majeed, Tariq; Metzger, Albert E.

    2004-01-01

    Northern auroral regions of Earth were imaged using the High-Resolution Camera (HRC-1) aboard the Chandra X-Ray Observatory (CXO) at 10 epochs (each approx.20 min duration) between mid-December 2003 and mid-April 2004. These observations aimed at searching for Earth s soft (<2 keV) x-ray aurora in a comparative study with Jupiter s x-ray aurora, where a pulsating x-ray "hot-spot" has been previously observed by Chandra. The first Chandra soft x-ray observations of Earth s aurora show that it is highly variable (intense arcs, multiple arcs, diffuse patches, at times absent). In at least one of the observations an isolated blob of emission is observed near the expected cusp location. A fortuitous overflight of DMSP satellite F13 provided SSJ/4 energetic particle measurements above a bright arc seen by Chandra on 24 January 2004, 20:01-20:22 UT. A model of the emissions expected strongly suggests that the observed soft x-ray signal is produced by electron bremsstrahlung.

  13. First Terrestrial Soft X-Ray Auroral Observation by the Chandra X-Ray Observatory

    NASA Technical Reports Server (NTRS)

    Bhardwaj, Anil; Gladstone, G. Randall; Elsner, Ronald F.; Oestgaard, Nikolai; Waite, J. Hunter, Jr.; Cravens, Thomas E.; Chang, Shen-Wu; Majeed, Tariq; Metzger, Albert E.

    2007-01-01

    Northern auroral regions of Earth were imaged with energetic photons in the 0.1-10keV range using the High-Resolution Camera (HRC-I) aboard the Chandra X-ray Observatory at 10 epochs (each approx.20 min duration) between mid- December 2003 and mid-April 2004. These observations aimed at searching for Earth's soft (< 2 keV) X-ray aurora in a comparative study with Jupiter's X-ray aurora, where a pulsating X-ray "hot-spot" has been previously observed by Chandra. The first Chandra soft X-ray observations of Earth's aurora show that it is highly variable 0ntense arcs, multiple arcs, diffuse patches, at times absent). In at least one of the observations an isolated blob of emission is observed near the expected cusp location. A fortuitous overflight of DMSP satellite F13 provided SSJ/4 energetic particle measurements above a bright arc seen by Chandra on 24 January 2004, 20:01-20:22 UT. A model of the emissions expected strongly suggests that the observed soft X-ray signal is bremsstrahlung and characteristic K-shell line emissions of nitrogen and oxygen in the atmosphere produced by electrons.

  14. Soft x-ray holographic microscopy

    NASA Astrophysics Data System (ADS)

    Stickler, Daniel; Frömter, Robert; Stillrich, Holger; Menk, Christian; Tieg, Carsten; Streit-Nierobisch, Simone; Sprung, Michael; Gutt, Christian; Stadler, Lorenz-M.; Leupold, Olaf; Grübel, Gerhard; Oepen, Hans Peter

    2010-01-01

    We present a new x-ray microscopy technique based on Fourier transform holography (FTH), where the sample is separate from the optics part of the setup. The sample can be shifted with respect to the holography optics, thus large-scale or randomly distributed objects become accessible. As this extends FTH into a true microscopy technique, we call it x-ray holographic microscopy (XHM). FTH allows nanoscale imaging without the need for nanometer-size beams. Simple Fourier transform yields an unambiguous image reconstruction. We demonstrate XHM by studying the magnetic domain evolution of a Co/Pt multilayer film as function of locally varied iron overlayer thickness.

  15. Soft x-ray imaging using Polaroid Land films

    SciTech Connect

    Wong, C.S.; Choi, P.; Deeney, C.

    1988-02-01

    It is demonstrated in this note that optical Polaroid Land films can be used as a convenient detector in the soft x-ray region. The performance of Polaroid 667 film has been found to be comparable to that of the Kodak direct exposure film (DEF) for soft x-ray pinhole imaging. By a suitable choice of multiple filters, qualitative information about a dense plasma has been obtained.

  16. Filters for soft X-ray solar telescopes

    NASA Technical Reports Server (NTRS)

    Spiller, Eberhard; Grebe, Kurt; Golub, Leon

    1990-01-01

    Soft X-ray telescopes require filters that block visible and infrared light and have good soft X-ray transmission. The optical properties of possible materials are discussed, and the fabrication and testing methods for the filters used in a 10-inch normal incidence telescope for 63 A are described. The best performances in the 44-114-A wavelength range are obtained with foils of carbon and rhodium.

  17. Soft x-ray reduction camera for submicron lithography

    DOEpatents

    Hawryluk, A.M.; Seppala, L.G.

    1991-03-26

    Soft x-ray projection lithography can be performed using x-ray optical components and spherical imaging lenses (mirrors), which form an x-ray reduction camera. The x-ray reduction is capable of projecting a 5x demagnified image of a mask onto a resist coated wafer using 4.5 nm radiation. The diffraction limited resolution of this design is about 135 nm with a depth of field of about 2.8 microns and a field of view of 0.2 cm[sup 2]. X-ray reflecting masks (patterned x-ray multilayer mirrors) which are fabricated on thick substrates and can be made relatively distortion free are used, with a laser produced plasma for the source. Higher resolution and/or larger areas are possible by varying the optic figures of the components and source characteristics. 9 figures.

  18. Soft x-ray reduction camera for submicron lithography

    DOEpatents

    Hawryluk, Andrew M.; Seppala, Lynn G.

    1991-01-01

    Soft x-ray projection lithography can be performed using x-ray optical components and spherical imaging lenses (mirrors), which form an x-ray reduction camera. The x-ray reduction is capable of projecting a 5x demagnified image of a mask onto a resist coated wafer using 4.5 nm radiation. The diffraction limited resolution of this design is about 135 nm with a depth of field of about 2.8 microns and a field of view of 0.2 cm.sup.2. X-ray reflecting masks (patterned x-ray multilayer mirrors) which are fabricated on thick substrates and can be made relatively distortion free are used, with a laser produced plasma for the source. Higher resolution and/or larger areas are possible by varying the optic figures of the components and source characteristics.

  19. Soft X-Ray Emissions from Planets and Moons

    NASA Technical Reports Server (NTRS)

    Bhardwaj, A.; Gladstone, G. R.; Elsner, R. F.; Waite, J. H., Jr.; Grodent, D.; Cravens, T. E.; Howell, R. R.; Metzger, A. E.; Ostgaard, N.; Maurellis, A.; Six, N. Frank (Technical Monitor)

    2002-01-01

    A wide variety of solar system planetary bodies are now known to radiate in the soft x-ray energy (<5 keV) regime. These include planets (Earth, Jupiter, Venus, Saturn): bodies having thick atmosphere and with/without intrinsic magnetic field; planetary satellites (Moon, Io, Europa, Ganymede): bodies with no/thin atmosphere; and comets and Io plasma torus: bodies having extended tenuous atmosphere. Several different mechanisms have been proposed to explain the generation of soft x-rays from these objects. whereas in the hard x-ray energy range (>10 keV) x-rays mainly result from electron bremsstrahlung process. In this paper we present a brief review of the x-ray observations on each of the planetary bodies and discuss their characteristics and proposed source mechanisms.

  20. Resonant soft X-ray scattering on protein solutions

    NASA Astrophysics Data System (ADS)

    Ye, Dan; Le, Thinh; Wang, Cheng; Zwart, Peter; Gomez, Esther; Gomez, Enrique

    Protein structure is crucial for biological function, such that characterizing protein folding and packing is important for the design of therapeutics and enzymes. We propose resonant soft X-ray scattering (RSOXS) as an approach to study proteins and other biological assemblies in solution. Calculations of the scattering contrast suggest that soft X-ray scattering is more sensitive than hard X-ray scattering, because of contrast generated at the absorption edges of constituent elements such as carbon, nitrogen and oxygen. We have examined the structure of bovine serum albumin (BSA) in solution by RSOXS. We find that by varying incident X-ray energies, we are able to achieve higher scattering contrast near the absorption edge. From our RSOXS scattering result we are able to reconstruct the structure of BSA in 3D. These RSOXS results also agree with hard X-ray experiments, including crystallographic data. Our study demonstrates the potential of RSOXS for studying protein structure in solution.

  1. Ultra high resolution soft x-ray tomography

    SciTech Connect

    Haddad, W.S.; Trebes, J.E.; Goodman, D.M.

    1995-07-19

    Ultra high resolution three dimensional images of a microscopic test object were made with soft x-rays using a scanning transmission x-ray microscope. The test object consisted of two different patterns of gold bars on silicon nitride windows that were separated by {approximately}5{mu}m. A series of nine 2-D images of the object were recorded at angles between {minus}50 to +55 degrees with respect to the beam axis. The projections were then combined tomographically to form a 3-D image by means of an algebraic reconstruction technique (ART) algorithm. A transverse resolution of {approximately}1000 {Angstrom} was observed. Artifacts in the reconstruction limited the overall depth resolution to {approximately}6000 {Angstrom}, however some features were clearly reconstructed with a depth resolution of {approximately}1000 {Angstrom}. A specially modified ART algorithm and a constrained conjugate gradient (CCG) code were also developed as improvements over the standard ART algorithm. Both of these methods made significant improvements in the overall depth resolution bringing it down to {approximately}1200 {Angstrom} overall. Preliminary projection data sets were also recorded with both dry and re-hydrated human sperm cells over a similar angular range.

  2. Effects of soft x-ray irradiation on cell ultrastructure

    NASA Astrophysics Data System (ADS)

    Ford, Thomas W.; Page, Anton M.; Foster, Guy F.; Stead, Anthony D.

    1993-01-01

    The future of x-ray microscopy lies mainly in its potential for imaging fresh, hydrated biological material at a resolution superior to that of light microscopy. For the image to be accepted as representing the cellular organization of the living cell, it is essential that artefacts are not introduced as a result of the image collection system. One possible source of artefacts is cellular damage resulting form the irradiation of the material with soft x rays. Cells of the unicellular alga Chlorella have been examined by transmission electron microscopy (TEM) following exposure to different doses of monochromatic (380 eV) soft x rays. Extreme ultrastructural damage has been detected following doses of 103 - 104 Gy, in particular loss of cellular membranes such as the internal thylakoid membranes of the chloroplast. This is discussed in relation to dosage commonly used for imaging by soft x-ray microscopy.

  3. The soft X-ray diffuse background

    NASA Technical Reports Server (NTRS)

    Mccammon, D.; Burrows, D. N.; Sanders, W. T.; Kraushaar, W. L.

    1982-01-01

    Maps of the diffuse X-ray background intensity covering essentially the entire sky with approx. 7 deg spatial resolution are presented for seven energy bands. The data were obtained on a series of ten sounding rocket flights conducted over a seven-year period. The different nature of the spatial distributions in different bands implies at least three distinct origins for the diffuse X-rays, none of which is well-understood. At energies or approx. 2000 eV, an isotropic and presumably extraglalactic 500 and 1000 eV, an origin which is at least partially galactic seems called for. At energies 284 eV, the observed intensity is anticorrelated with neutral hydrogen column density, but we find it unlikely that this anticorrelation is simply due to absorption of an extragalactic or halo source.

  4. Soft X-ray Polarimetry Development

    NASA Astrophysics Data System (ADS)

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

    2016-07-01

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

  5. X-Ray Emission from the Soft X-Ray Transient Aquila X-1

    NASA Technical Reports Server (NTRS)

    Tavani, Marco

    1998-01-01

    Aquila X-1 is the most prolific of soft X-ray transients. It is believed to contain a rapidly spinning neutron star sporadically accreting near the Eddington limit from a low-mass companion star. The interest in studying the repeated X-ray outbursts from Aquila X-1 is twofold: (1) studying the relation between optical, soft and hard X-ray emission during the outburst onset, development and decay; (2) relating the spectral component to thermal and non-thermal processes occurring near the magnetosphere and in the boundary layer of a time-variable accretion disk. Our investigation is based on the BATSE monitoring of Aquila X-1 performed by our group. We observed Aquila X-1 in 1997 and re-analyzed archival information obtained in April 1994 during a period of extraordinary outbursting activity of the source in the hard X-ray range. Our results allow, for the first time for this important source, to obtain simultaneous spectral information from 2 keV to 200 keV. A black body (T = 0.8 keV) plus a broken power-law spectrum describe accurately the 1994 spectrum. Substantial hard X-ray emission is evident in the data, confirming that the accretion phase during sub-Eddington limit episodes is capable of producing energetic hard emission near 5 x 10(exp 35) ergs(exp -1). A preliminary paper summarizes our results, and a more comprehensive account is being written. We performed a theoretical analysis of possible emission mechanisms, and confirmed that a non-thermal emission mechanism triggered in a highly sheared magnetosphere at the accretion disk inner boundary can explain the hard X-ray emission. An anticorrelation between soft and hard X-ray emission is indeed prominently observed as predicted by this model.

  6. Nanoimaging cells using soft X-ray tomography.

    PubMed

    Parkinson, Dilworth Y; Epperly, Lindsay R; McDermott, Gerry; Le Gros, Mark A; Boudreau, Rosanne M; Larabell, Carolyn A

    2013-01-01

    Soft X-ray microscopy is ideally suited to visualizing and quantifying biological cells. Specimens, including eukaryotic cells, are imaged intact, unstained and fully hydrated, and therefore visualized in a near-native state. The contrast in soft X-ray microscopy is generated by the differential attenuation of X-rays by the molecules in the specimen-water is relatively transmissive to this type of illumination compared to carbon and nitrogen. The attenuation of X-rays by the specimen follows the Beer-Lambert law, and therefore both linear and a quantitative measure of thickness and chemical species present at each point in the cell. In this chapter, we will describe the procedures and computational methods that lead to 50 nm (or better) tomographic reconstructions of cells using soft X-ray microscope data, and the subsequent segmentation and analysis of these volumetric reconstructions. In addition to being a high-fidelity imaging modality, soft X-ray tomography is relatively high-throughput; a complete tomographic data set can be collected in a matter of minutes. This new modality is being applied to imaging cells that range from small prokaryotes to stem cells obtained from mammalian tissues. PMID:23086890

  7. Review of soft x-ray lasers and their applications

    SciTech Connect

    Skinner, C.H.

    1991-03-01

    The emerging technology of soft x-ray lasers is in a transition phase between the first laboratory demonstrations of gain and the acceptance of soft x-ray lasers as practical tools for novel applications. Current research is focused on several fronts. The operational wavelength range has been extended to the water window'', important for applications in the life sciences. Gain has also been generated with substantially simpler technology (such as a 6J laser) and this augurs well for the commercially availability in the near future of soft x-ray lasers for a variety of applications. Advanced soft x-ray laser concepts are being developed from investigations into ultra-high intensity laser/matter interactions. The first paper a brief historical perspective of x-ray microscopy and holography have begun. In this paper a brief historical perspective of x-ray laser development will be followed by a review of recent advances in recombination, collisional and photo-pumped systems and applications. A summary of current gain-length performance achieved in laboratories worldwide is presented. Near term prospects for applications to novel fields are discussed. 81 refs., 9 figs., 1 tab.

  8. First Terrestrial Soft X-ray Aurora Observations by Chandra

    NASA Technical Reports Server (NTRS)

    Bhardwaj, Anil; Elsner, Ronald F.; Gladstone, G. Randall; Waite, J. Hunter, Jr.; Cravens, Thomas E.; Ostgaard, Nikolai; Chang, Shen-Wu; Metzger, Albert E.; Majeed, Tariq

    2004-01-01

    Northern polar "auroral" regions of Earth was observed by High-Resolution Camera in imaging mode (T32C-I) aboard Chandra X-Ray Observatory (CXO) during mid December 2003 - mid April 2004. Ten CXO observations, each approximately 20 min duration, were made in a non-conventional method (due to CXO technical issues), such that Chandra was aimed at a fixed point in sky and the Earth's polar cusp was allowed to drift through the HRC-I field-of-view. The observations were performed when CXO was near apogee and timed during northern winter mostly near midnight (6 hr), except two observations which occurred around 1200 UT, so that northern polar region is entirely in dark and solar fluoresced x-ray contamination can be avoided. These observations were aimed at searching the Earth's soft x-ray aurora and to do a comparative study with Jupiter's x-ray aurora, where a pulsating x-ray hot-spot near the northern magnetic pole has been observed by Chandra that implies a particle source region near Jupiter's magnetopause, and entry of heavy solar wind ions due to high-latitude reconnection as a viable explanation for the soft x-ray emissions. The first Chandra soft (0.1-2 keV) x-ray observations of Earth's aurora show that it is highly variable (intense arc, multiple arcs, diffuse, at times almost absent). In at least one of the observations an isolated blob of emission is observed where we expect cusp to be: giving indication of solar wind charge-exchange signature in x-rays. We are comparing the Chandra x-ray observations with observations at other wavelengths and particle data from Earth-orbiting satellites and solar wind measurements from near-Earth ACE and SOH0 spacecraft. Preliminary results from these unique CXO-Earth observations will be presented and discussed.

  9. Soft x-ray imager onboard ASTRO-H

    NASA Astrophysics Data System (ADS)

    Tsunemi, Hiroshi; Hayashida, Kiyoshi; Nakajima, Hiroshi; Tsuru, Takeshi Go; Tanaka, Takaaki; Dotani, Tadayasu; Ozaki, Masayuki; Natsukari, Chikara; Tomida, Hiroshi; Hiraga, Junko S.; Kohmura, Takayoshi; Murakami, Hiroshi; Mori, Koji; Yamauchi, Makoto; Hatsukade, Isamu; Bamba, Aya

    2013-09-01

    The Soft X-ray Imager, SXI, is an X-ray CCD camera onboard the ASTRO-H satellite to be launched in 2015. ASTRO-H will carry two types of soft X-ray detector. The X-ray calorimeter, SXS, has an excellent energy resolution with a narrow field of view while the SXI has a medium energy resolution with a large field of view, 38' square. We employ 4 CCDs of P-channel type with a depletion layer of 200 μm. Having passed the CDR, we assemble the FM so that we can join the final assembly. We present here the SXI status and its expected performance in orbit.

  10. Soft x-ray amplification in a plasma waveguide

    SciTech Connect

    Kato, Y.; Kodama, R.; Daido, H.; Murai, K.; Yuan, G.; Ninomiya, S.; Neely, D.; MacPhee, A.; Lewis, C. L. S.; Choi, I. W.; Nam, C. H.; Kawachi, T.

    1995-05-01

    Narrow divergence soft x-ray laser has been generated by double-pass amplification in a curved slab target with a neon-like germanium laser. Considering the electron density profile with the curved slab target, the plasma acts as a one-dimensional waveguide to the x-ray laser beam. Beam parameters such as radius and wavefront curvature of the Gaussian beam are derived from the analysis on beam propagation in the waveguide. Possibility for generating a single-mode x-ray laser beam by multiple-pulse pumping of the curved target is discussed.

  11. Fabrication of a focusing soft X-ray collector payload

    NASA Technical Reports Server (NTRS)

    Davis, J. M.; Decaprio, A. R.; Manko, H.; Ting, J. W. S.

    1976-01-01

    A large area X-ray focusing collector with arc minute resolution and a position sensitive detector capable of operating in the soft X-ray region was developed for use on sounding rockets in studying stellar X-ray sources. The focusing payload consists of the following components, which are described: (1) a crossed paraboloid mirror assembly; (2) an aspect camera and star tracker; (3) a focal plane assembly containing an imaging proportional counter and its preamplifiers, high voltage power supplies and gas system; (4) a fiducial system; and (5) housekeeping, data handling, instrumentation and telemetry electronics. The design, tests, and operation are described.

  12. The interstellar medium and the soft X-ray background

    NASA Technical Reports Server (NTRS)

    Snowden, S. L.

    1996-01-01

    The soft X-ray background (SXRB) surface brightness provides data to study the approximately 10(exp 6) K plasma of the local interstellar medium of our Galaxy. Various studies were carried out in order to search for negative correlation, or shadowing, of the SXRB, and were coupled with interstellar medium absorption line studies. The purpose was to determine whether the distances to the shadowing material will lead to a three dimensional mapping of the X-ray emitting, and X-ray absorbing components.

  13. Contact microscopy with a soft x-ray laser

    SciTech Connect

    DiCicco, D.S.; Kim, D.; Rosser, R.J.; Skinner, C.H.; Suckewer, S.; Gupta, A.P.; Hirschberg, J.G.

    1989-03-01

    A soft x-ray laser of output energy 1-3 mJ at 19.2 nm has been used to record high resolution images of biological specimens. The contact images were recorded on photoresist which was later viewed in a scanning electron microscope. We also present a Composite Optical X- ray Laser Microscope ''COXRALM'' of novel design. 14 refs., 8 figs., 1 tab.

  14. The very soft X-ray emission of X-ray-faint early-type galaxies

    NASA Technical Reports Server (NTRS)

    Pellegrini, S.; Fabbiano, G.

    1994-01-01

    A recent reanaylsis of Einstein data, and new ROSAT observations, have revealed the presence of at least two components in the X-ray spectra of X-ray faint early-type galaxies: a relatively hard component (kT greater than 1.5 keV), and a very soft component (kT approximately 0.2-0.3 keV). In this paper we address the problem of the nature of the very soft component and whether it can be due to a hot interstellar medium (ISM), or is most likely originated by the collective emission of very soft stellar sources. To this purpose, hydrodynamical evolutionary sequences for the secular behavior of gas flows in ellipticals have been performed, varying the Type Ia supernovae rate of explosion, and the dark matter amount and distribution. The results are compared with the observational X-ray data: the average Einstein spectrum for six X-ray faint early-type galaxies (among which are NGC 4365 and NGC 4697), and the spectrum obtained by the ROSAT pointed observation of NGC 4365. The very soft component could be entirely explained with a hot ISM only in galaxies such as NGC 4697, i.e., when the depth of the potential well-on which the average ISM temperature strongly depends-is quite shallow; in NGC 4365 a diffuse hot ISM would have a temperature larger than that of the very soft component, because of the deeper potential well. So, in NGC 4365 the softest contribution to the X-ray emission comes certainly from stellar sources. As stellar soft X-ray emitters, we consider late-type stellar coronae, supersoft sources such as those discovered by ROSAT in the Magellanic Clouds and M31, and RS CVn systems. All these candidates can be substantial contributors to the very soft emission, though none of them, taken separately, plausibly accounts entirely for its properties. We finally present a model for the X-ray emission of NGC 4365, to reproduce in detail the results of the ROSAT pointed observation, including the Position Sensitive Proportional Counter (PSPC) spectrum and radial

  15. Soft X-ray Spectromicroscopy of Polymers

    NASA Astrophysics Data System (ADS)

    Ade, Harald

    1997-03-01

    The development of Near Edge X-ray Absorption Fine Structure (NEXAFS) microscopy^1 and linear dichroism microscopy^2 over the last few years utilizing the X1-Scanning Transmission X-ray Microscope (X1-STXM) at the National Synchrotron Light Source provides excellent specificity to various functional groups and moieties in organic molecules and polymeric materials at a spatial resolution of 50 nm. This chemical specificity can be utilized to map the distribution of various compounds in a material, or to micro-chemically analyze small sample areas. Examples of applications include the study of various phase-separated polymers (polyurethanes, liquid crystalline polyesters), multicomponent polymer blends, polymer laminates, and other organic materials such as coal^3. Linear dichroism microscopy furthermore explores the polarization dependence of NEXAFS in (partially) oriented materials, and can determine the orientation of specific functional groups. Applications of linear dichroism microscopy have focused so far on determining the relative degree of radial orientation in Kevlar fibers^3. ^1 H. Ade, X. Zhang, S. Cameron, C. Costello, J. Kirz, and S. Williams, Science 258, 972 (1992). ^2 H. Ade and B. Hsiao, Science 262, 1427 (1993). ^3 Acknowledgement: My callaborators are B. Hsiao, S. Subramoney, B. Wood, I. Plotzker, E. Rightor, G. Mitchell, C. Sloop, D.-J. Liu, S.-C. Liu, J. Marti, C. Zimba, A. P. Smith, R. Spontak, R. Fornes, R. Gilbert, C. Cody, A. Hitchcock and S. Urquhart. The X1-STXM is built and maintained by J. Kirz and C. Jacobsen and their groups. Work supported by: NSF Young Investigator Award (DMR-9458060), DuPont Young Professor Grant, and Dow Chemical.

  16. Isolated attosecond soft X-rays and water window XAFS

    NASA Astrophysics Data System (ADS)

    Biegert, Jens

    2016-05-01

    We demonstrate generation of isolated attosecond soft X-ray pulses with duration less than 350 as at the carbon K-edge at 284 eV. This reproducible and CEP stable attosecond soft X-ray continuum covers the entire water window from 200 eV to 550 eV with a flux of 7.3x 107 photons/s and corresponds to a pulse energy of 2.9 pJ. We demonstrate the utility of our table-top source through soft X-ray near-edge fine-structure spectroscopy at K-shell absorption edges in condensed matter and retrieve the specific absorption features corresponding to the binding orbitals. We believe that these results herald attosecond material science by bridging the gap between ultrafast temporal resolution and element specific probing at the fundamental absorption edges of matter.

  17. Soft x-ray spectroscopy in atmospheric pressure helium

    SciTech Connect

    Roper, M.D.; van der Laan, G.; Flaherty, J.V.; Padmore, H.A. )

    1992-01-01

    We report on an environmental chamber, which is attached to a UHV beamline, in which soft x-ray measurements can be done at atmospheric pressure in helium. X-ray measurements in air can only be performed at energies above about 3 keV because of the strong absorption of soft x rays by oxygen and nitrogen. However, a low-{ital Z} scatterer such as helium has a long absorption length for soft x rays even at atmospheric pressure. Thus, this new chamber allows soft x-ray experiments to be performed on samples with physical properties that are incompatible with UHV conditions, e.g., liquid and frozen aqueous solutions, corrosive materials, etc. A helium-tight tank has been installed behind the vacuum experimental chamber of the double crystal beamline 3.4 at the Daresbury SRS. The tank is purged with helium at atmospheric pressure and the gas in the tank is isolated from the high vacuum of the rest of the beamline by a thin mylar window which is supported on a capillary array. The tank contains a sample stage, two ionization chambers and a parallel-plate gas proportional counter for fluorescence detection of dilute samples, which has produced good results on the {ital K} edges of Cl, S, and P.

  18. X-Ray Morphology,Kinematics and Geometry of the Eridanus Soft X-Ray Enhancement

    NASA Astrophysics Data System (ADS)

    Guo, Zhiyu; Burrows, David N.; Sanders, Wilton T.; Snowden, Steve L.; Penprase, Bryan E.

    1994-12-01

    We present mosaics of X-ray intensity maps and spectral fit results for selected regions of the Eridanus soft X-ray Enhancement (EXE), as well as kinematics of the X-ray absorbing clouds in the EXE region and geometrical properties of this X-ray emitting bubble. The work is based on pointed observations with the ROSAT Position Sensitive Proportional Counter, 21 cm observations with the NRAO 140 foot telescope at Green Bank and interstellar Na D line observations with the NOAO Coude Feed telescope at Kitt Peak. The ROSAT pointed observations examine two regions of the EXE. The first is an X-ray absorption lane produced by an IR filament which is located at galactic coordinates of about (199(deg) , -45(deg) ). The second is in the vicinity of the northern (galactic) boundary of the 1/4 keV EXE, at galactic coordinates of about (200(deg) , -25(deg) ). Both our spatial and spectral analysis suggest that variations in emission measure and NH are primarily reponsible for the observed variations of the X-ray intensity. Using 100mu intensities obtained from IRAS maps and NH column densities obtained from our X-ray spectral fits, we find 100 microns/NH ratios across the IR filament that are compatible with typical high latitude values. Maps of the X-ray absorbing clouds in the EXE region at 21 cm reveal that these clouds may belong to two different expanding systems, with one possibly associated with our Local Bubble and the other with the boundary of the EXE. Combination of 21 cm data with interstellar Na D line observations toward stars in the directions of some of the X-ray absorbing clouds along (l,b) ~ (200(deg) ,-40(deg) ) indicate that the near side of the EXE is farther than 151 pc and the distance to the center of the EXE at this latitude is about 226 pc. The density and the thermal pressure found for this X-ray emitting superbubble are 0.015 cm(-3) and 4.9 times 10(4) cm(-3) K.

  19. Soft X-ray Excesses and X-ray Line Variability in Cygnus X-3

    NASA Astrophysics Data System (ADS)

    Varlotta, Angelo; McCollough, Michael L

    2014-06-01

    Cygnus X-3 is an X-ray binary (XRB) system containing a stellar-mass compact object, most likely a black hole, and a Wolf-Rayet companion star, which produces collimated, relativistic jets, placing it in the sub-class of XRBs known as microquasars. During a Swift/XRT monitoring program of Cygnus X-3, a soft X-ray excess (below 1 keV) was observed at certain states and phases of activity. This soft excess appears to be similar to the variable soft emission observed in Seyfert galaxies. The presence of these features in Cygnus X-3 would argue for a greater support of the black-hole nature of the compact object and serve to better highlight the similarities of microquasars and AGN. We present the results of our investigations of these soft excesses, as well as the variations of the X-ray Fe line region (6.4-7.0 keV) as a function of the state activity and orbital phase.

  20. Soft X-ray contact microscopy of nematode Caenorhabditis elegans

    NASA Astrophysics Data System (ADS)

    Poletti, G.; Orsini, F.; Batani, D.; Bernardinello, A.; Desai, T.; Ullschmied, J.; Skala, J.; Kralikova, B.; Krousky, E.; Juha, L.; Pfeifer, M.; Kadlec, Ch.; Mocek, T.; Präg, A.; Renner, O.; Cotelli, F.; Lora Lamia, C.; Zullini, A.

    2004-08-01

    Soft X-ray Contact Microscopy (SXCM) of Caenorhabditis elegans nematodes with typical length ~800 μ m and diameter ~30 μ m has been performed using the PALS laser source of wavelength λ = 1.314~μ m and pulse duration τ (FWHM) = 400 ps. Pulsed soft X-rays were generated using molybdenum and gold targets with laser intensities I ≥ 1014 W/cm2. Images have been recorded on PMMA photo resists and analyzed using an atomic force microscope operating in contact mode. Cuticle features and several internal organs have been identified in the SXCM images including lateral field, cuticle annuli, pharynx, and hypodermal and neuronal cell nuclei.

  1. A soft x-ray octadecyl hydrogen maleate crystal spectrograph

    SciTech Connect

    Fan, P.Z.; Fill, E.E.; Tietang, G.

    1996-03-01

    A crystal spectrograph is described which can be used to investigate laser-produced plasmas in the region of soft x rays at wavelengths of up to 60 A. The spectrograph uses an octadecyl hydrogen maleate crystal with a 2{ital d} of 63.5 A, combined with a very thin carbon filter (3000 A thick). As examples of its application, soft x-ray spectra in the range of 43{endash}51 A from laser plasmas of Si and Cu are presented. A spectral resolution of {lambda}/{Delta}{lambda}=1100 is deduced from the spectra. {copyright} {ital 1996 American Institute of Physics.}

  2. Bright circularly polarized soft X-ray high harmonics for X-ray magnetic circular dichroism

    PubMed Central

    Fan, Tingting; Grychtol, Patrik; Knut, Ronny; Hernández-García, Carlos; Hickstein, Daniel D.; Zusin, Dmitriy; Gentry, Christian; Dollar, Franklin J.; Mancuso, Christopher A.; Hogle, Craig W.; Kfir, Ofer; Legut, Dominik; Carva, Karel; Ellis, Jennifer L.; Dorney, Kevin M.; Chen, Cong; Shpyrko, Oleg G.; Fullerton, Eric E.; Cohen, Oren; Oppeneer, Peter M.; Milošević, Dejan B.; Becker, Andreas; Jaroń-Becker, Agnieszka A.; Popmintchev, Tenio; Murnane, Margaret M.; Kapteyn, Henry C.

    2015-01-01

    We demonstrate, to our knowledge, the first bright circularly polarized high-harmonic beams in the soft X-ray region of the electromagnetic spectrum, and use them to implement X-ray magnetic circular dichroism measurements in a tabletop-scale setup. Using counterrotating circularly polarized laser fields at 1.3 and 0.79 µm, we generate circularly polarized harmonics with photon energies exceeding 160 eV. The harmonic spectra emerge as a sequence of closely spaced pairs of left and right circularly polarized peaks, with energies determined by conservation of energy and spin angular momentum. We explain the single-atom and macroscopic physics by identifying the dominant electron quantum trajectories and optimal phase-matching conditions. The first advanced phase-matched propagation simulations for circularly polarized harmonics reveal the influence of the finite phase-matching temporal window on the spectrum, as well as the unique polarization-shaped attosecond pulse train. Finally, we use, to our knowledge, the first tabletop X-ray magnetic circular dichroism measurements at the N4,5 absorption edges of Gd to validate the high degree of circularity, brightness, and stability of this light source. These results demonstrate the feasibility of manipulating the polarization, spectrum, and temporal shape of high harmonics in the soft X-ray region by manipulating the driving laser waveform. PMID:26534992

  3. Bright circularly polarized soft X-ray high harmonics for X-ray magnetic circular dichroism.

    PubMed

    Fan, Tingting; Grychtol, Patrik; Knut, Ronny; Hernández-García, Carlos; Hickstein, Daniel D; Zusin, Dmitriy; Gentry, Christian; Dollar, Franklin J; Mancuso, Christopher A; Hogle, Craig W; Kfir, Ofer; Legut, Dominik; Carva, Karel; Ellis, Jennifer L; Dorney, Kevin M; Chen, Cong; Shpyrko, Oleg G; Fullerton, Eric E; Cohen, Oren; Oppeneer, Peter M; Milošević, Dejan B; Becker, Andreas; Jaroń-Becker, Agnieszka A; Popmintchev, Tenio; Murnane, Margaret M; Kapteyn, Henry C

    2015-11-17

    We demonstrate, to our knowledge, the first bright circularly polarized high-harmonic beams in the soft X-ray region of the electromagnetic spectrum, and use them to implement X-ray magnetic circular dichroism measurements in a tabletop-scale setup. Using counterrotating circularly polarized laser fields at 1.3 and 0.79 µm, we generate circularly polarized harmonics with photon energies exceeding 160 eV. The harmonic spectra emerge as a sequence of closely spaced pairs of left and right circularly polarized peaks, with energies determined by conservation of energy and spin angular momentum. We explain the single-atom and macroscopic physics by identifying the dominant electron quantum trajectories and optimal phase-matching conditions. The first advanced phase-matched propagation simulations for circularly polarized harmonics reveal the influence of the finite phase-matching temporal window on the spectrum, as well as the unique polarization-shaped attosecond pulse train. Finally, we use, to our knowledge, the first tabletop X-ray magnetic circular dichroism measurements at the N4,5 absorption edges of Gd to validate the high degree of circularity, brightness, and stability of this light source. These results demonstrate the feasibility of manipulating the polarization, spectrum, and temporal shape of high harmonics in the soft X-ray region by manipulating the driving laser waveform. PMID:26534992

  4. Soft X-ray Absorption Edges in LMXBs

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The XMM observation of LMC X-2 is part of our program to study X-ray absorption in the interstellar medium (ISM). This program includes a variety of bright X-ray binaries in the Galaxy as well as the Magellanic Clouds (LMC and SMC). LMC X-2 is located near the heart of the LMC. Its very soft X-ray spectrum is used to determine abundance and ionization fractions of neutral and lowly ionized oxygen of the ISM in the LMC. The RGS spectrum so far allowed us to determine the O-edge value to be for atomic O, the EW of O-I in the ls-2p resonance absorption line, and the same for O-II. The current study is still ongoing in conjunction with other low absorption sources like Sco X-1 and the recently observed X-ray binary 4U 1957+11.

  5. Soft x-ray streak camera for laser fusion applications

    SciTech Connect

    Stradling, G.L.

    1981-04-01

    This thesis reviews the development and significance of the soft x-ray streak camera (SXRSC) in the context of inertial confinement fusion energy development. A brief introduction of laser fusion and laser fusion diagnostics is presented. The need for a soft x-ray streak camera as a laser fusion diagnostic is shown. Basic x-ray streak camera characteristics, design, and operation are reviewed. The SXRSC design criteria, the requirement for a subkilovolt x-ray transmitting window, and the resulting camera design are explained. Theory and design of reflector-filter pair combinations for three subkilovolt channels centered at 220 eV, 460 eV, and 620 eV are also presented. Calibration experiments are explained and data showing a dynamic range of 1000 and a sweep speed of 134 psec/mm are presented. Sensitivity modifications to the soft x-ray streak camera for a high-power target shot are described. A preliminary investigation, using a stepped cathode, of the thickness dependence of the gold photocathode response is discussed. Data from a typical Argus laser gold-disk target experiment are shown.

  6. Microspectroscopic soft X-ray analysis of keratin based biofibers.

    PubMed

    Späth, Andreas; Meyer, Markus; Semmler, Sonja; Fink, Rainer H

    2015-03-01

    Scanning soft X-ray transmission microspectroscopy (STXM) and transmission electron microscopy (TEM) have been employed for a high-resolution morphological and chemical analysis of hair fibers from human, sheep and alpaca. STXM allows optimum contrast imaging of the main hair building blocks due to tuneable photon energy. Chemical similarities and deviations for the human hair building blocks as well as for the three investigated species are discussed on the basis of the local near-edge X-ray absorption fine structure (NEXAFS). The spectra of melanosomes corroborate the state-of-the-art model for the chemical structure of eumelanin. Complementary TEM micrographs reveal the occurrence of cortex sectioning in alpaca hair to some extent. A spectroscopic analysis for human hair cortex indicates low mass loss upon soft X-ray irradiation, but transformation of chemical species with decreasing amount of peptide bonds and increasing NEXAFS signal for unsaturated carbon-carbon bonds. PMID:25553413

  7. Soft x-ray virtual diagnostics for tokamak simulations

    SciTech Connect

    Kim, J. S.; Zhao, L.; Bogatu, I. N.; In, Y.; Turnbull, A.; Osborne, T.; Maraschek, M.; Comer, K.

    2009-11-15

    The numerical toolset, FAR-TECH Virtual Diagnostic Utility, for generating virtual experimental data based on theoretical models and comparing it with experimental data, has been developed for soft x-ray diagnostics on DIII-D. The virtual (or synthetic) soft x-ray signals for a sample DIII-D discharge are compared with the experimental data. The plasma density and temperature radial profiles needed in the soft x-ray signal modeling are obtained from experimental data, i.e., from Thomson scattering and electron cyclotron emission. The virtual soft x-ray diagnostics for the equilibriums have a good agreement with the experimental data. The virtual diagnostics based on an ideal linear instability also agree reasonably well with the experimental data. The agreements are good enough to justify the methodology presented here for utilizing virtual diagnostics for routine comparison of experimental data. The agreements also motivate further detailed simulations with improved physical models such as the nonideal magnetohydrodynamics contributions (resistivity, viscosity, nonaxisymmetric error fields, etc.) and other nonlinear effects, which can be tested by virtual diagnostics with various stability modeling.

  8. Soft x-ray virtual diagnostics for tokamak simulations.

    PubMed

    Kim, J S; Zhao, L; Bogatu, I N; In, Y; Turnbull, A; Osborne, T; Maraschek, M; Comer, K

    2009-11-01

    The numerical toolset, FAR-TECH Virtual Diagnostic Utility, for generating virtual experimental data based on theoretical models and comparing it with experimental data, has been developed for soft x-ray diagnostics on DIII-D. The virtual (or synthetic) soft x-ray signals for a sample DIII-D discharge are compared with the experimental data. The plasma density and temperature radial profiles needed in the soft x-ray signal modeling are obtained from experimental data, i.e., from Thomson scattering and electron cyclotron emission. The virtual soft x-ray diagnostics for the equilibriums have a good agreement with the experimental data. The virtual diagnostics based on an ideal linear instability also agree reasonably well with the experimental data. The agreements are good enough to justify the methodology presented here for utilizing virtual diagnostics for routine comparison of experimental data. The agreements also motivate further detailed simulations with improved physical models such as the nonideal magnetohydrodynamics contributions (resistivity, viscosity, nonaxisymmetric error fields, etc.) and other nonlinear effects, which can be tested by virtual diagnostics with various stability modeling. PMID:19947727

  9. Lensless imaging of nanoporous glass with soft X-rays

    DOE PAGESBeta

    Turner, Joshua J.; Nelson, Johanna; Huang, Xiaojing; Steinbrener, Jan; Jacobsen, Chris

    2013-06-01

    Coherent soft X-ray diffraction has been used to image nanoporous glass structure in two dimensions using different methods. The merit of the reconstructions was judged using a new method of Fourier phase correlation with a final, refined image. The porous structure was found to have a much larger average size then previously believed.

  10. Lasers, extreme UV and soft X-ray

    DOE PAGESBeta

    Nilsen, Joseph

    2015-09-20

    Three decades ago, large ICF lasers that occupied entire buildings were used as the energy sources to drive the first X-ray lasers. Today X-ray lasers are tabletop, spatially coherent, high-repetition rate lasers that enable many of the standard optical techniques such as interferometry to be extended to the soft X-ray regime between wavelengths of 10 and 50 nm. Over the last decade X-ray laser performance has been improved by the use of the grazing incidence geometry, diode-pumped solid-state lasers, and seeding techniques. The dominant X-ray laser schemes are the monopole collisional excitation lasers either driven by chirped pulse amplification (CPA)more » laser systems or capillary discharge. The CPA systems drive lasing in neon-like or nickel-like ions, typically in the 10 – 30 nm range, while the capillary system works best for neon-like argon at 46.9 nm. Most researchers use nickel-like ion lasers near 14 nm because they are well matched to the Mo:Si multilayer mirrors that have peak reflectivity near 13 nm and are used in many applications. As a result, the last decade has seen the birth of the X-ray free electron laser (XFEL) that can reach wavelengths down to 0.15 nm and the inner-shell Ne laser at 1.46 nm.« less

  11. Lasers, extreme UV and soft X-ray

    SciTech Connect

    Nilsen, Joseph

    2015-09-20

    Three decades ago, large ICF lasers that occupied entire buildings were used as the energy sources to drive the first X-ray lasers. Today X-ray lasers are tabletop, spatially coherent, high-repetition rate lasers that enable many of the standard optical techniques such as interferometry to be extended to the soft X-ray regime between wavelengths of 10 and 50 nm. Over the last decade X-ray laser performance has been improved by the use of the grazing incidence geometry, diode-pumped solid-state lasers, and seeding techniques. The dominant X-ray laser schemes are the monopole collisional excitation lasers either driven by chirped pulse amplification (CPA) laser systems or capillary discharge. The CPA systems drive lasing in neon-like or nickel-like ions, typically in the 10 – 30 nm range, while the capillary system works best for neon-like argon at 46.9 nm. Most researchers use nickel-like ion lasers near 14 nm because they are well matched to the Mo:Si multilayer mirrors that have peak reflectivity near 13 nm and are used in many applications. As a result, the last decade has seen the birth of the X-ray free electron laser (XFEL) that can reach wavelengths down to 0.15 nm and the inner-shell Ne laser at 1.46 nm.

  12. A soft X-ray lag detected in Centaurus A

    NASA Astrophysics Data System (ADS)

    Tachibana, Yutaro; Kawamuro, Taiki; Ueda, Yoshihiro; Shidatsu, Megumi; Arimoto, Makoto; Yoshii, Taketoshi; Yatsu, Yoichi; Saito, Yoshihiko; Pike, Sean; Kawai, Nobuyuki

    2016-06-01

    We performed time-lag analysis on the X-ray light curves of Centaurus A (Cen A) obtained by the Gas Slit Camera (GSC) aboard the Monitor of All-sky X-ray Image (MAXI) in three energy bands (2-4 keV, 4-10 keV, and 10-20 keV). We discovered a soft X-ray lag relative to higher energies (soft lag) on a timescale of days in a flaring episode by employing the discrete correlation function (DCF) and the z-transformed discrete correlation function (ZDCF) method. In the episode, a peak and a centroid in the DCF and the ZDCF was observed at a soft lag of ˜ 5 d in 2-4 keV versus 4-10 keV and in 4-10 keV versus 10-20 keV, and ˜ 10 d in 2-4 keV versus 10-20 keV. We found it difficult to explain the observed X-ray variation by a single energy injection with the one-zone synchrotron self-Compton (SSC) model, in which the soft lags in these three energy bands reflect the different cooling times of the relativistic electrons, by assuming the magnetic field and minimum Lorentz factor estimated from a broad-band spectral energy distribution. Alternatively, if the phenomenon is interpreted as cooling of Comptonizing electrons in a corona covering the accretion disk, the temperature of the corona producing the variable X-rays should be ˜ 10 keV for reconciliation with the soft lag in the energy range of 2-20 keV.

  13. A soft X-ray lag detected in Centaurus A

    NASA Astrophysics Data System (ADS)

    Tachibana, Yutaro; Kawamuro, Taiki; Ueda, Yoshihiro; Shidatsu, Megumi; Arimoto, Makoto; Yoshii, Taketoshi; Yatsu, Yoichi; Saito, Yoshihiko; Pike, Sean; Kawai, Nobuyuki

    2016-03-01

    We performed time-lag analysis on the X-ray light curves of Centaurus A (Cen A) obtained by the Gas Slit Camera (GSC) aboard the Monitor of All-sky X-ray Image (MAXI) in three energy bands (2-4 keV, 4-10 keV, and 10-20 keV). We discovered a soft X-ray lag relative to higher energies (soft lag) on a timescale of days in a flaring episode by employing the discrete correlation function (DCF) and the z-transformed discrete correlation function (ZDCF) method. In the episode, a peak and a centroid in the DCF and the ZDCF was observed at a soft lag of ˜ 5 d in 2-4 keV versus 4-10 keV and in 4-10 keV versus 10-20 keV, and ˜ 10 d in 2-4 keV versus 10-20 keV. We found it difficult to explain the observed X-ray variation by a single energy injection with the one-zone synchrotron self-Compton (SSC) model, in which the soft lags in these three energy bands reflect the different cooling times of the relativistic electrons, by assuming the magnetic field and minimum Lorentz factor estimated from a broad-band spectral energy distribution. Alternatively, if the phenomenon is interpreted as cooling of Comptonizing electrons in a corona covering the accretion disk, the temperature of the corona producing the variable X-rays should be ˜ 10 keV for reconciliation with the soft lag in the energy range of 2-20 keV.

  14. Soft x-ray diagnostics for pulsed power machines

    SciTech Connect

    Idzorek, G.C.; Coulter, W.L.; Walsh, P.J.; Montoya, R.R.

    1995-08-01

    A variety of soft x-ray diagnostics are being fielded on the Los Alamos National Laboratory Pegasus and Procyon pulsed power systems and also being fielded on joint US/Russian magnetized target fusion experiments known as MAGO (Magnitoye Obzhatiye). The authors have designed a low-cost modular photoemissive detector designated the XRD-96 that uses commercial 1100 series aluminum for the photocathode. In addition to photocathode detectors a number of designs using solid state silicon photodiodes have been designed and fielded. They also present a soft x-ray time-integrated pinhole camera system that uses standard type TMAX-400 photographic film that obviates the need for expensive and no longer produced zero-overcoat soft x-ray emulsion film. In a typical experiment the desired spectral energy cuts, signal intensity levels, and desired field of view will determine diagnostic geometry and x-ray filters selected. The authors have developed several computer codes to assist in the diagnostic design process and data deconvolution. Examples of the diagnostic design process and data analysis for a typical pulsed power experiment are presented.

  15. Transition radiation very soft X-ray source

    NASA Astrophysics Data System (ADS)

    Umiastowski, K.; Nguyen, A.

    1994-05-01

    There is a growing interest in the transition radiation (TR), as a soft X-ray source, in the last few years. Many papers have been published on calculations or experiments in the 1-10 keV X-ray energy range using 50-200 MeV electron accelerators. We investigate the possibility to generate very soft X-rays (λ = 12 nm) with low-energy electron accelerator (5-20 MeV). Very little information is available on TR in this range of photon wavelength and electron energy. A stack of 20 foils of beryllium placed in vacuum was used in our computer simulation. Calculation shows that for 1 mA electron beam current, radiation with few mW intensity can be produced. Emitted photons are quasi-monoenergetic (FWHM less than 5%), and well collimated. The aim of our study is to investigate the possibility of fabricate a soft X-ray source, much more compact than synchrotron source and producing an intense and quasi-coherent radiation, for industrial applications.

  16. High spatial resolution soft-x-ray microscopy

    SciTech Connect

    Meyer-Ilse, W.; Medecki, H.; Brown, J.T.

    1997-04-01

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

  17. Exploring nanomagnetism with soft x-ray microscopy

    SciTech Connect

    Fischer, P.; Kim, D.-H.; Mesler, B.L.; Chao, W.; Sakdinawat,A.E.; Anderson, E.H.

    2006-10-30

    Magnetic soft X-ray microscopy images magnetism in nanoscale systems with a spatial resolution down to 15nm provided by state-of-the-art Fresnel zone plate optics. X-ray magnetic circular dichroism (X-MCD) is used as element-specific magnetic contrast mechanism similar to photoemission electron microscopy (PEEM), however, with volume sensitivity and the ability to record the images in varying applied magnetic fields which allows to study magnetization reversal processes at fundamental length scales. Utilizing a stroboscopic pump-probe scheme one can investigate fast spin dynamics with a time resolution down to 70 ps which gives access to precessional and relaxation phenomena as well as spin torque driven domain wall dynamics in nanoscale systems. Current developments in zone plate optics aim for a spatial resolution towards 10nm and at next generation X-ray sources a time resolution in the fsec regime can be envisioned.

  18. Soft X-Ray Polarimetry with a CubeSat

    NASA Astrophysics Data System (ADS)

    Kaaret, Philip

    2016-07-01

    We describe an instrument capable of measuring the polarization of astrophysical sources in soft X-rays that can be accomplished at modest cost by exploiting CubeSats as novel vehicles for high energy astrophysics. The instrument would re-use technologies that will be demonstrated on the HaloSat cubesat that is currently under construction. Potential target include thermally-emitting isolated neutron stars and blazars. Measurement of the polarization of X-rays emitted from the surface of a highly magnetized neutron star provides a means to test a unique signature of strong-field quantum electrodynamics and probe the neutron star magnetic field and X-ray emission geometry. Polarization measurements of blazars should strongly constrain jet emission models.

  19. Soft x-ray holographic tomography for biological specimens

    NASA Astrophysics Data System (ADS)

    Gao, Hongyi; Chen, Jianwen; Xie, Honglan; Li, Ruxin; Xu, Zhizhan; Jiang, Shiping; Zhang, Yuxuan

    2003-10-01

    In this paper, we present some experimental results on X -ray holography, holographic tomography, and a new holographic tomography method called pre-amplified holographic tomography is proposed. Due to the shorter wavelength and the larger penetration depths, X-rays provide the potential of higher resolution in imaging techniques, and have the ability to image intact, living, hydrated cells w ithout slicing, dehydration, chemical fixation or stain. Recently, using X-ray source in National Synchrotron Radiation Laboratory in Hefei, we have successfully performed some soft X-ray holography experiments on biological specimen. The specimens used in the experiments was the garlic clove epidermis, we got their X-ray hologram, and then reconstructed them by computer programs, the feature of the cell walls, the nuclei and some cytoplasm were clearly resolved. However, there still exist some problems in realization of practical 3D microscopic imaging due to the near-unity refractive index of the matter. There is no X-ray optics having a sufficient high numerical aperture to achieve a depth resolution that is comparable to the transverse resolution. On the other hand, computer tomography needs a record of hundreds of views of the test object at different angles for high resolution. This is because the number of views required for a densely packed object is equal to the object radius divided by the desired depth resolution. Clearly, it is impractical for a radiation-sensitive biological specimen. Moreover, the X-ray diffraction effect makes projection data blur, this badly degrades the resolution of the reconstructed image. In order to observe 3D structure of the biological specimens, McNulty proposed a new method for 3D imaging called "holographic tomography (HT)" in which several holograms of the specimen are recorded from various illumination directions and combined in the reconstruction step. This permits the specimens to be sampled over a wide range of spatial

  20. The Interrelation of Soft and Hard X-Ray Emission During Solar Flares

    NASA Technical Reports Server (NTRS)

    Fisher, George H.

    1998-01-01

    The objective of this project is to determine the characteristics of flare energy transport processes through the study of soft X-rays, hard X-rays, and their interrelationships through analysis of Yohkoh SXT (Soft X-ray Telescope), HXT (Hard X- Ray Telescope) , and BCS (Bragg Crystal Spectrometer) data, and comparison with theoretical models.

  1. ASTRO-H Soft X-Ray Telescope (SXT)

    NASA Technical Reports Server (NTRS)

    Soong, Yang; Serlemitsos Peter J.; Okajima, Takashi; Hahne, Devin

    2011-01-01

    ASTRO-H is an astrophysics satellite dedicated for X-ray spectroscopic study non-dispersively and to carry out survey complementally, which will be borne out of US-Japanese collaborative effort. Among the onboard instruments there are four conically approximated Wolter-I X-ray mirrors, among which two of them are soft X-ray mirrors\\ of which the energy range is from a few hundred eV to 15 keY, currently being fabricated in the X-ray Optics Lab at Goddard Space Flight Center. The focal point instruments will be a calorimeter (SXS) and a CCD camera (SXI), respectively. The reflectors of the mirror are made of heat-formed aluminum substrate of the thickness gauged of 152 micron, 229 micron, and 305 micron of the alloy 5052 H-19, followed by epoxy replication on gold-sputtered smooth Pyrex cylindrical mandrels to acquire the X-ray reflective surface. The epoxy layer is 10 micron nominal and surface gold layer of 0.2 micron. Improvements on angular response over the Astro-El/Suzaku mirrors come from error reduction on the figure, the roundness, and the grazing angle/radius mismatching of the reflecting surface, and tighter specs and mechanical strength on supporting structure to reduce the reflector positioning and the assembly errors. In this paper, we report the results of calibration of the engineering model of SXT (EM), and project the quality of the flight mirrors.

  2. Viewing spin structures with soft x-ray microscopy

    SciTech Connect

    Fischer, Peter

    2010-06-01

    The spin of the electron and its associated magnetic moment marks the basic unit for magnetic properties of matter. Magnetism, in particular ferromagnetism and antiferromagnetism is described by a collective order of these spins, where the interaction between individual spins reflects a competition between exchange, anisotropy and dipolar energy terms. As a result the energetically favored ground state of a ferromagnetic system is a rather complex spin configuration, the magnetic domain structure. Magnetism is one of the eldest scientific phenomena, yet it is one of the most powerful and versatile utilized physical effects in modern technologies, such as in magnetic storage and sensor devices. To achieve highest storage density, the relevant length scales, such as the bit size in disk drives is now approaching the nanoscale and as such further developments have to deal with nanoscience phenomena. Advanced characterization tools are required to fully understand the underlying physical principles. Magnetic microscopes using polarized soft X-rays offer a close-up view into magnetism with unique features, these include elemental sensitivity due to X-ray magnetic dichroism effects as contrast mechanism, high spatial resolution provided by state-of-the-art X-ray optics and fast time resolution limited by the inherent time structure of current X-ray sources, which will be overcome with the introduction of ultrafast and high brilliant X-ray sources.

  3. Soft x-ray laser microscope. Final report

    SciTech Connect

    Suckewer, P.I.

    1990-10-01

    The program consisted of two phases (Phase I and Phase II). The goal of the Phase I (first year program) was to design and construct the Soft X-ray Laser Contact Microscope. Such microscope was constructed and adapted to PPL`s 18.2nm soft X-ray Laser (SXL), which in turn was modified and prepared for microscopy experiments. Investigation of the photoresist response to 18.2nm laser radiation and transmissivity of 0.1m thick silicion-nitride (Si{sub 3}N{sub 4}) windows were important initial works. The goal of the first year of Phase II was to construct X-ray contact microscope in combination with existing optical phase microscope, already used by biologists. In the second year of Phase II study of dehydrated Horeseshoe Crab and Hela cancer cells were performed with COXRALM. Also during Phase II, the Imaging X-Ray Laser Microscope (IXRALM) was designed and constructed. This paper describes the development of each of the microscopes and their application for research.

  4. Soft X-ray spectroscopy of the Cygnus Loop

    NASA Astrophysics Data System (ADS)

    McEntaffer, Randall L.

    My thesis work consisted of the design, fabrication and launch of a sounding rocket payload to observe the spectrum of the soft X-ray emission from the Cygnus Loop supernova remnant. This payload was designated the Cygnus X-ray Emission Spectroscopic Survey (CyXESS) and launched from White Sands Missile Range on November 20th, 2006. The novel X-ray spectrograph incorporated a wire- grid collimator feeding an array of gratings in the extreme off-plane mount which ultimately dispersed the spectrum onto never before flown Gaseous Electron Multiplier (GEM) detectors. This instrument recorded 65 seconds of usable data between 43-49.5 Å in two prominent features. The first feature near 45 Å is dominated by the He-like triplet of O VII in second order with contributions from Mg X and Si IX-Si XII in first order, while the second feature near 47.5 Å is first order S IX and S X. Fits to the spectra give an equilibrium plasma at log( T )=6.2 ( kT e =0.14 keV) and near cosmic abundances. This is consistent with previous observations, which demonstrated that the soft x-ray emission from the Cygnus Loop is dominated by interactions between the initial blast wave with the walls of a precursor formed cavity surrounding the Cygnus Loop.

  5. Soft X-ray polarimeter-spectrometer SOLPEX

    NASA Astrophysics Data System (ADS)

    Steslicki, Marek; Sylwester, Janusz; Plocieniak, Stefan; Bakala, Jaroslaw; Szaforz, Zaneta Anna; Scislowski, Daniel; Kowalinski, Miroslaw; Hernandez, Jose; Vadimovich Kuzin, Sergey; Shestov, Sergey

    2015-08-01

    We present an innovative soft X-ray polarimeter and spectrometer SOLPEX. The instrument will be mounted aboard the ISS within the Russian science complex KORTES. The measurements to be made by SOLPEX are expected to be of unprecedented quality in terms of sensitivity to detect the soft-X- ray polarization of solar emission emanating from active regions and flares in particular. Simultaneous measurements of the polarization degree and the other characteristics (eg. evolution of the spectra) constitute the last, rather unexplored area of solar X-ray spectroscopy providing substantial diagnostic potential. Second important science task to be addressed are the measurements of Doppler shifts in selected X-ray spectral emission lines formed in hot flaring sources. The novel-type Dopplerometer (flat Bragg crystal drum unit) is planned to be a part of SOLPEX and will allow to measure line Doppler shifts in absolute terms with unprecedented time resolution (fraction of a second) during the impulsive flare phases. We shall present some details of the SolpeX instrument and discuss observing sequences in a view of science objectives to be reached.

  6. PSPC soft x-ray observations of Seyfert 2 galaxies

    NASA Technical Reports Server (NTRS)

    Turner, T. J.; Urry, C. M.; Mushotzky, R. F.

    1993-01-01

    We present the results from ROSAT PSPC soft x-ray (0.1-2.0 keV) observations of six Seyfert 2 galaxies, chosen from the brightest Seyfert 2s detected with the Einstein Imaging Proportional Counter. All of the targets were detected with the ROSAT PSPC. Spatial analysis shows that the source density within a few arcmin of each Seyfert 2 galaxy is a factor of approximately eight higher than in the rest of the inner field of view of the PSPC images. In NGC1365 it appears that the serendipitous sources may be x-ray binary systems in the host galaxy. The proximity of the serendipitous sources, typically within a few arcmin of the target Seyfert 2, means that previous x-ray observations of the Seyfert 2 galaxies have been significantly contaminated, and that source confusion is important on a spatial scale of approximately 1 arcmin. Some spectra, most notably Mrk3 and NGC1365, indicate the presence of a high equivalent width soft x-ray line blend consistent with unresolved iron L and oxygen K emission.

  7. The soft x ray telescope for Solar-A

    NASA Technical Reports Server (NTRS)

    Brown, W. A.; Acton, L. W.; Bruner, M. E.; Lemen, J. R.; Strong, K. T.

    1989-01-01

    The Solar-A satellite being prepared by the Institute for Sapce and Astronautical Sciences (ISAS) in Japan is dedicated to high energy observations of solar flares. The Soft X Ray Telescope (SXT) is being prepared to provide filtered images in the 2 to 60 A interval. The flight model is now undergoing tests in the 1000 foot tunnel at MSFC. Launch will be in September 1991. Earlier resolution and efficiency tests on the grazing incidence mirror have established its performance in soft x rays. The one-piece, two mirror grazing incidence telescope is supported in a strain free mount separated from the focal plane assembly by a carbon-epoxy metering tube whose windings and filler are chosen to minimize thermal and hygroscopic effects. The CCD detector images both the x ray and the concentric visible light aspect telescope. Optical filters provide images at 4308 and 4700 A. The SXT will be capable of producing over 8000 of the smallest partial frame images per day, or fewer but larger images, up to 1024 x 1024 pixel images. Image sequence with two or more of the five x ray analysis filters, with automatic exposure compensation to optimize the charge collection by the CCD detector, will be used to provide plasma diagnostics. Calculations using a differential emission measure code were used to optimize filter selection over the range of emission measure variations and to avoid redundancy, but the filters were chosen primarily to give ratios that are monotonic in plasma temperature.

  8. The soft X ray excess in Einstein quasar spectra

    NASA Technical Reports Server (NTRS)

    Wilkes, Belinda J.; Masnou, Jean-Louis; Elvis, Martin; Mcdowell, Jonathan; Arnaud, Keith

    1989-01-01

    The soft X-ray excess component is studied for a signal to noise limited subsample of 14 quasars from the WE87 sample observed with the Einstein Imaging Proportional Counter (IPC). Detailed analysis of the IPC data, combined with Einstein Monitor Proportional Counter (MPC) data where possible, and use of accurate galactic N sub H values allows estimation of the strength of any excess and improvement of constraints on the spectral slope at higher X-ray energies. A significant excess in 9 of the 14 objects is found. It is confined in all but one case to below 0.6 keV and variable in the two cases where there are multiple observations. The relation of the soft excess to other continuum properties of the quasars is investigated.

  9. Quantifying the Exospheric Component of Soft X-ray Emission

    NASA Technical Reports Server (NTRS)

    Kuntz, Kip; Collier, Michael R.; Snowden, Steven L.; Robertson, Ina; Hansen, Kenneth; Cravens, Thomas

    2007-01-01

    High charge state heavy ions in the solar wind exchange charge with ambient neutral gas. This process creates a product ion in an excited state. During the radiative cascade process, EUV and X-ray photons are emitted with energies in the range of about 100 eV to 1 keV. Because the terrestrial exospheric density at the nominal magnetopause location is relatively high, approx. 10 cu cm, solar wind charge exchange, or SWCX, can be observed by Earth-orbiting soft X-ray instruments such as the ROSAT Position Sensitive Proportional Counters (PSPC). In this presentation, we will compare simulated and observed soft Xray emission during an event on August 18-19, 1991 and discuss the role of exospheric SWCX emission for this and other events.

  10. Phase dispersion X-ray imaging of murine soft tissue

    NASA Astrophysics Data System (ADS)

    Ingal, V. N.; Ingal, E. A.

    2013-12-01

    The generation of phase-contrast (PC) images in the phase-dispersion introscopy (PDI) technique is the subject of this paper. Conditions for extreme sensitivity to murine soft-tissue anatomy are discussed. The unique information content and good contrast of the minutest details of anatomy, together with the high brilliance of X-ray optics, give the authors confidence that the PDI method can be successfully applied for medical diagnostics.

  11. ASTRO-H Soft X-ray Telescope (SXT)

    NASA Astrophysics Data System (ADS)

    Soong, Yang; Okajima, Takashi; Serlemitsos, Peter J.; Odell, Stephen L.; Ramsey, Brian D.; Gubarev, Mikhail V.; Ishida, Manabu; Maeda, Yoshitomo; Iizuka, Ryo; Hayashi, Takayuki; Tawara, Yuzuru; Furuzawa, Akihiro; Mori, Hideyuki; Miyazawa, Takuya; Kunieda, Hideyo; Awaki, Hisamitsu; Sugita, Satoshi; Tamura, Keisuke; Ishibashi, Kazunori; Izumiya, Takanori; Minami, Sari; Sato, Toshiki; Tomikawa, Kazuki; Kikuchi, Naomichi; Iwase, Toshihiro

    2014-07-01

    ASTRO-H is an astrophysics satellite dedicated for non-dispersive X-ray spectroscopic study on selective celestial X-ray sources. Among the onboard instruments there are four Wolter-I X-ray mirrors of their reflectors' figure in conical approximation. Two of the four are soft X-ray mirrors1, of which the energy range is from a few hundred eV to 15 keV within the effective aperture being defined by the nested reflectors' radius ranging between 5.8 cm to 22.5 cm. The focal point instruments will be a calorimeter (SXS) and a CCD camera (SXI), respectively. The mirrors were in quadrant configuration with photons being reflected consecutively in the primary and secondary stage before converging on the focal plane of 5.6 m away from the interface between the two stages. The reflectors of the mirror are made of heat-formed aluminum substrate of the thickness gauged of 152 μm, 229 μm, and 305 μm of the alloy 5052 H-19, followed by epoxy replication on gold-sputtered smooth Pyrex cylindrical mandrels to acquire the X-ray reflective surface. The epoxy layer is 10 m nominal and surface gold layer of 0.2 μm. Improvements on angular response over its predecessors, e.g. Astro-E1/Suzaku mirrors, come from error reduction on the figure, the roundness, and the grazing angle/radius mismatching of the reflecting surface, and tighter specs and mechanical strength on supporting structure to reduce the reflector positioning and the assembly errors. Each soft x-ray telescope (SXT), SXT-1 or SXT-2, were integrated from four independent quadrants of mirrors. The stray-light baffles, in quadrant configuration, were mounted onto the integrated mirror. Thermal control units were attached to the perimeter of the integrated mirror to keep the mirror within operating temperature in space. The completed instrument went through a series of optical alignment, thus made the quadrant images confocal and their optical axes in parallel to achieve highest throughput possible. Environmental tests

  12. Tokamak T-10 soft x-ray imaging diagnostic

    NASA Astrophysics Data System (ADS)

    Bobrovskij, G. A.; Kislov, D. A.; Lyadina, E. S.; Savrukhin, P. V.

    1991-04-01

    Three arrays of silicon surface-barrier diodes were recently installed on T-10 (R=1.5 m, a=0.3 m). The detectors view the plasma cross section along 58 chords spaced in the poloidal direction at one toroidal location. The tomographic reconstruction technique allows one to obtain the time evolution of the two-dimensional soft x-ray intensity profiles in the energy range of 2.5-15 keV. The field of view covered the main part of the plasma (r/a<0.7) with a spatial resolution as small as 2 cm, which is consistent with the scale of the processes under study. The signals are digitized at rates up to 100 kHz and stored in 464K (total) memory (8K per channel). The measured soft x-ray emission was applicable for investigation of the magnetohydrodynamic instabilities, heat and particle transport, and plasma position control. Studies of the evolution of soft x-ray perturbations were made in ohmically and ECRH heated plasmas. It was shown that the effect of ECRH on the plasma parameters (transport coefficients, sawtooth activity, modification of the electron temperature profiles) depends on the position of the EC resonance zone within the plasma cross section. The tomographic reconstruction revealed the different mechanisms of sawtooth crashes in the T-10 plasma.

  13. Soft x ray properties of the Geminga pulsar

    NASA Technical Reports Server (NTRS)

    Halpern, J. P.; Ruderman, M.

    1993-01-01

    The ROSAT soft x ray spectrum and pulse profile of the Geminga pulsar are analyzed and interpreted in terms of thermal emission from the surface of the neutron star. The x ray spectrum appears to consist of two blackbody components with T(sub 1) = (5.2 +/- 1.0) x 10 (exp 5) K and T(sub 2) approximately 3 x 10(exp 6) K, respectively. The inferred ratio of surface areas, A(sub 2)/A(sub 1), is approximately 3 x 10(exp -5). Both components are highly modulated at the pulsar rotation period, but the harder x ray pulse is narrower, and leads the main (soft) x ray pulse by about 105 deg of phase. The soft x ray component is interpreted as photospheric cooling of much of the neutron star's surface area, while the small, hot region could be part of the much smaller polar cap heated by energetic particles flowing inward from the magnetospheric accelerator which is responsible for the production of Geminga's gamma rays. Geminga's gamma ray emission is consistent with outer-magnetosphere accelerator models for highly inclined dipoles. These predict the beaming of energetic gamma rays close enough to the star to give copious e(+/-) production in the stellar magnetic field and a large circumstellar pair density from pair inflow toward the surface. These pairs may quench radio emission, and also reflect most of the hard polar cap x rays back to the stellar surface by cyclotron resonance scattering. They are then reemitted from that much larger area at the lower temperature T(sub 1). The single-peaked nature of the x ray pulse and its energy-dependent phase suggest an off-center dipole geometry for the surface magnetic field. Under the assumption that the soft x ray emission comes from the full surface of a neutron star of radius R = 10 km, a distance estimate of (150-400) pc is derived. This range is consistent with the fit interstellar column density of (1.5 +/- 0.5) x 10(exp 20) cm(exp -2). Distances less than 150 pc are probably ruled out both by the lower limit on the column

  14. Anomalous X-ray diffraction with soft X-ray synchrotron radiation.

    PubMed

    Carpentier, P; Berthet-Colominas, C; Capitan, M; Chesne, M L; Fanchon, E; Lequien, S; Stuhrmann, H; Thiaudière, D; Vicat, J; Zielinski, P; Kahn, R

    2000-07-01

    Anomalous diffraction with soft X-ray synchrotron radiation opens new possibilities in protein crystallography and materials science. Low-Z elements like silicon, phosphorus, sulfur and chlorine become accessible as new labels in structural studies. Some of the heavy elements like uranium exhibit an unusually strong dispersion at their M(V) absorption edge (lambdaMV = 3.497 A, E(MV) = 3545 eV) and so does thorium. Two different test experiments are reported here showing the feasibility of anomalous X-ray diffraction at long wavelengths with a protein containing uranium and with a salt containing chlorine atoms. With 110 electrons the anomalous scattering amplitude of uranium exceeds by a factor of 4 the resonance scattering of other strong anomalous scatterers like that of the lanthanides at their L(III) edge. The resulting exceptional phasing power of uranium is most attractive in protein crystallography using the multi-wavelength anomalous diffraction (MAD) method. The anomalous dispersion of an uranium derivative of asparaginyl-tRNA synthetase (hexagonal unit cell; a = 123.4 A, c = 124.4 A) has been measured for the first time at 4 wavelengths near the M(V) edge using the beamline ID1 of ESRF (Grenoble, France). The present set up allowed to measure only 30% of the possible reflections at a resolution of 4 A, mainly because of the low sensitivity of the CCD detector. In the second experiment, the dispersion of the intensity of 5 X-ray diffraction peaks from pentakismethylammonium undecachlorodibismuthate (PMACB, orthorhombic unit cell; a = 13.003 A, b = 14.038 A, c = 15.450 A) has been measured at 30 wavelengths near the K absorption edge of chlorine (lambdaK = 4.397 A, EK= 2819.6 eV). All reflections within the resolution range from 6.4 A to 3.4 A expected in the 20 degree scan were observed. The chemical state varies between different chlorine atoms of PMACB, and so does the dispersion of different Bragg peaks near the K-edge of chlorine. The results reflect

  15. Soft x-ray holography and microscopy of biological cells

    NASA Astrophysics Data System (ADS)

    Chen, Jianwen; Gao, Hongyi; Xie, Honglan; Li, Ruxin; Xu, Zhizhan

    2003-10-01

    Some experimental results on soft X-ray microscopy and holography imaging of biological specimens are presented in the paper. As we know, due to diffraction effects, there exists a resolution limit determined by wavelength λ and numerical aperture NA in conventional optical microscopy. In order to improve resolution, the num erical aperture should be made as large as possible and the wavelength as short as possible. Owing to the shorter wavelength, X-rays provide the potential of higher resolution in X-ray microscopy, holography image and allow for exam ination the interior structures of thicker specimens. In the experiments, we used synchrotron radiation source in Hefei as light source. Soft X-rays come from a bending magnet in 800 M eV electron storage ring with characteristic wavelength of 2.4 nm. The continuous X-ray spectrums are monochromatized by a zone-plate and a pinhole with 300 m diameter. The experimental set-up is typical contact microscopic system, its main advantage is simplicity and no special optical element is needed. The specimens used in the experiments of microscopic imaging are the colibacillus, the gingko vascular hundle and the fritillaries ovary karyon. The specimen for holographic imaging is the spider filam ents. The basic structures of plant cells such as the cell walls, the cytoplasm and the karyon especially the joint structures between the cells are observed clearly. An experimental study on a thick biological specimen that is a whole sporule w ith the thickness of about 30 μm is performed. In the holographic experiments, the experimental setup is typical Gabor in-line holography. The specimen is placed in line with X-ray source, which provides both the reference w aves and specimen illum ination. The specimen is some spider filament, which adhere to a Si3N4 film. The recording medium is PM M A, which is placed at recording distance of about 400 μm from the specimen. The hologram s were reconstructed by digital method with 300 nm

  16. Coherent X-ray diffraction from collagenous soft tissues

    SciTech Connect

    Berenguer de la Cuesta, Felisa; Wenger, Marco P.E.; Bean, Richard J.; Bozec, Laurent; Horton, Michael A.; Robinson, Ian K.

    2009-09-11

    Coherent X-ray diffraction has been applied in the imaging of inorganic materials with great success. However, its application to biological specimens has been limited to some notable exceptions, due to the induced radiation damage and the extended nature of biological samples, the last limiting the application of most part of the phasing algorithms. X-ray ptychography, still under development, is a good candidate to overcome such difficulties and become a powerful imaging method for biology. We describe herein the feasibility of applying ptychography to the imaging of biological specimens, in particular collagen rich samples. We report here speckles in diffraction patterns from soft animal tissue, obtained with an optimized small angle X-ray setup that exploits the natural coherence of the beam. By phasing these patterns, dark field images of collagen within tendon, skin, bone, or cornea will eventually be obtained with a resolution of 60-70 nm. We present simulations of the contrast mechanism in collagen based on atomic force microscope images of the samples. Simulations confirmed the 'speckled' nature of the obtained diffraction patterns. Once inverted, the patterns will show the disposition and orientation of the fibers within the tissue, by enhancing the phase contrast between protein and no protein regions of the sample. Our work affords the application of the most innovative coherent X-ray diffraction tools to the study of biological specimens, and this approach will have a significant impact in biology and medicine because it overcomes many of the limits of current microscopy techniques.

  17. The soft X-ray turnoff of Nova Muscae 1983

    NASA Technical Reports Server (NTRS)

    Shanley, L.; Ogelman, H.; Gallagher, J. S.; Orio, M.; Krautter, J.

    1995-01-01

    Nova GQ Muscae 1983 was detected by ROSAT as a luminous 'supersoft' X-ray source in 1992, nearly a decade after outburst. Further, this is the only classical postnova known to have maintained constant luminosity on a timescale predicted by theoretical models. Follow-up observations were made with the ROSAT position-sensitive proportional counter in 1993 January and September, and complemented with B-band photometry taken in 1993 January. By 1993 January, the X-ray count rate had declined by a factor of 17, while there was neither an appreciable decrease in the optical magnitude nor a change in the amplitude of modulation. In 1993 September the soft X-ray flux was below the ROSAT threshold limit, implying a decrease of a factor greater than or equal to 30 in the count rate. This decline can be interpreted by the turnoff of nuclear processes due to the complete consumption of the residual hydrogen-rich envelope. However, the optical luminosity of the system is not simply coupled to the X-ray luminosity (e.g., through reprocessing).

  18. The superconducting high-resolution soft X-ray spectrometer at the advanced biological and environmental X-ray facility

    NASA Astrophysics Data System (ADS)

    Friedrich, S.; Drury, O. B.; George, S. J.; Cramer, S. P.

    2007-11-01

    We have built a 36-pixel superconducting tunnel junction X-ray spectrometer for chemical analysis of dilute samples in the soft X-ray band. It offers an energy resolution of ˜10-20 eV FWHM below 1 keV, a solid angle coverage of ˜10 -3, and can be operated at total rates of up to ˜10 6 counts/s. Here, we describe the spectrometer performance in speciation measurements by fluorescence-detected X-ray absorption spectroscopy at the Advanced Biological and Environmental X-ray facility at the ALS synchrotron.

  19. 2D and 3D X-Ray Structural Microscopy Using Submicron-Resolution Laue Microdiffraction

    SciTech Connect

    Budai, John D.; Yang, Wenge; Larson, Bennett C.; Tischler, Jonathan Z.; Liu, Wenjun; Ice, Gene E.

    2010-11-10

    We have developed a scanning, polychromatic x-ray microscopy technique with submicron spatial resolution at the Advanced Photon Source. In this technique, white undulator radiation is focused to submicron diameter using elliptical mirrors. Laue diffraction patterns scattered from the sample are collected with an area detector and then analyzed to obtain the local crystal structure, lattice orientation, and strain tensor. These new microdiffraction capabilities have enabled both 2D and 3D structural studies of materials on mesoscopic length-scales of tenths-to-hundreds of microns. For thin samples such as deposited films, 2D structural maps are obtained by step-scanning the area of interest. For example, 2D x-ray microscopy has been applied in studies of the epitaxial growth of oxide films. For bulk samples, a 3D differential-aperture x-ray microscopy technique has been developed that yields the full diffraction information from each submicron volume element. The capabilities of 3D x-ray microscopy are demonstrated here with measurements of grain orientations and grain boundary motion in polycrystalline aluminum during 3D thermal grain growth. X-ray microscopy provides the needed, direct link between the experimentally measured 3D microstructural evolution and the results of theory and modeling of materials processes on mesoscopic length scales.

  20. Phase contrast enhanced high resolution X-ray imaging and tomography of soft tissue

    NASA Astrophysics Data System (ADS)

    Jakubek, Jan; Granja, Carlos; Dammer, Jiri; Hanus, Robert; Holy, Tomas; Pospisil, Stanislav; Tykva, Richard; Uher, Josef; Vykydal, Zdenek

    2007-02-01

    A tabletop system for digital high resolution and high sensitivity X-ray micro-radiography has been developed for small-animal and soft-tissue imaging. The system is based on a micro-focus X-ray tube and the semiconductor hybrid position sensitive Medipix2 pixel detector. Transmission radiography imaging, conventionally based only on absorption, is enhanced by exploiting phase-shift effects induced in the X-ray beam traversing the sample. Phase contrast imaging is realized by object edge enhancement. DAQ is done by a novel fully integrated USB-based readout with online image generation. Improved signal reconstruction techniques make use of advanced statistical data analysis, enhanced beam hardening correction and direct thickness calibration of individual pixels. 2D and 3D micro-tomography images of several biological samples demonstrate the applicability of the system for biological and medical purposes including in-vivo and time dependent physiological studies in the life sciences.

  1. Discovery of hard X-ray outbursts from the soft X-ray transient Aquila X-1.

    NASA Astrophysics Data System (ADS)

    Harmon, B. A.; Wilson, C. A.; Tavani, M.; Zhang, S. N.; Rubin, B. C.; Paciesas, W. S.; Ford, E. C.; Kaaret, P.

    1996-11-01

    We report the BATSE discovery of hard X-ray outbursts from the soft X-ray transient Aquila X-1 (Aql X-1). Aql X-1 is the most prolific of the soft X-ray transient sources and it has been known to produce large outbursts near the Eddington limit in the 1-10keV energy band. The typical recurrence time of outbursts is about 1-year. Aql X-1 shows type I X-ray bursts during the decay phase of the X-ray outbursts and is believed to contain a neutron star. These characteristics of Aql X-1 make it an ideal system to study time variable hard X-ray emission from accreting neutron stars. BATSE has monitored Aql X-1 continuously since the Compton Observatory mission began in April 1991. Several episodes of hard X-ray emission with durations of weeks to months have been detected in 1991-1994. These episodes are coincident with substantial brightening of the optical counterpart and to a lesser degree with observations of soft X-ray emission by ROSAT, EURECA/WATCH and ASCA. We find fluxes in the 20-100mCrab range with hard spectra extending to above 100keV and power law spectral fits yielding photon indices between -2 and -3.

  2. Soft x-ray coherent diffraction imaging on magnetic nanostructures

    NASA Astrophysics Data System (ADS)

    Shi, Xiaowen; Lee, James; Mishra, Shrawan; Parks, Daniel; Tyliszczak, Tolek; Shapiro, David; Roy, Sujoy; Kevan, Steve; Stxm Team At Als Collaboration; Soft X-Ray Microscopy Group At Als Collaboration; Soft X-ray scattering at ALS, LBL Team

    2014-03-01

    Coherent soft X-rays diffraction imaging enable coherent magnetic resonance scattering at transition metal L-edge to be probed so that magnetic domains could be imaged with very high spatial resolution with phase contrast, reaching sub-10nm. One of the overwhelming advantages of using coherent X-rays is the ability to resolve phase contrast images with linearly polarized light with both phase and absorption contrast comparing to real-space imaging, which can only be studied with circularly polarized light with absorption contrast only. Here we report our first results on high-resolution of magnetic domains imaging of CoPd multilayer thin film with coherent soft X-ray ptychography method. We are aiming to resolve and understand magnetic domain wall structures with the highest obtainable resolution here at Advanced Light Source. In principle types of magnetic domain walls could be studied so that Neel or Bloch walls can be distinguished by imaging. This work at LBNL was supported by the Director, Office of Science, Office of Basic Energy Sciences, of the US Department of Energy (contract no. DE-AC02- 05CH11231).

  3. Soft X-ray scanning transmission X-ray microscopy (STXM) of actinide particles.

    PubMed

    Nilsson, Hans J; Tyliszczak, Tolek; Wilson, Richard E; Werme, Lars; Shuh, David K

    2005-09-01

    A descriptive account is given of our most recent research on the actinide dioxides with the Advanced Light Source Molecular Environmental Science (ALS-MES) Beamline 11.0.2 soft X-ray scanning transmission X-ray microscope (STXM) at the Lawrence Berkeley National Laboratory (LBNL). The ALS-MES STXM permits near-edge X-ray absorption fine structure (NEXAFS) and imaging with 30-nm spatial resolution. The first STXM spectromicroscopy NEXAFS spectra at the actinide 4d5/2 edges of the imaged transuranic particles, NpO2 and PuO2, have been obtained. Radiation damage induced by the STXM was observed in the investigation of a mixed oxidation state particle (Np(V,VI)) and was minimized during collection of the actual spectra at the 4d5/2 edge of the Np(V,VI) solid. A plutonium elemental map was obtained from an irregular PuO2 particle with the dimensions of 650 x 650 nm. The Pu 4d5/2 NEXAFS spectra were collected at several different locations from the PuO2 particle and were identical. A representative oxygen K-edge spectrum from UO2 was collected and resembles the oxygen K-edge from the bulk material. The unique and current performance of the ALS-MES STXM at extremely low energies (ca. 100 eV) that may permit the successful measurement of the actinide 5d edge is documented. Finally, the potential of STXM as a tool for actinide investigations is briefly discussed. PMID:16021423

  4. ASTRO-H Soft X-ray Telescope (SXT)

    NASA Astrophysics Data System (ADS)

    Soong, Yang; Serlemitsos, Peter J.; Okajima, Takashi; Hahne, Devin

    2011-09-01

    ASTRO-H is an astrophysics satellite dedicated for X-ray spectroscopic study non-dispersively and to carry out survey complementally, which will be borne out of US-Japanese collaborative effort. Among the onboard instruments there are four conically approximated Wolter-I X-ray mirrors, among which two of them are soft X-ray mirrors1, of which the energy range is from a few hundred eV to 15 keV, currently being fabricated in the X-ray Optics Lab at Goddard Space Flight Center. The focal point instruments will be a calorimeter (SXS) and a CCD camera (SXI), respectively. The reflectors of the mirror are made of heat-formed aluminum substrate of the thickness gauged of 152 μm, 229 μm, and 305 μm of the alloy 5052 H-19, followed by epoxy replication on gold-sputtered smooth Pyrex cylindrical mandrels to acquire the X-ray reflective surface. The epoxy layer is 10 μm nominal and surface gold layer of 0.2 μm. Improvements on angular response over the Astro-E1/Suzaku mirrors come from error reduction on the figure, the roundness, and the grazing angle/radius mismatching of the reflecting surface, and tighter specs and mechanical strength on supporting structure to reduce the reflector positioning and the assembly errors. In this paper, we report the results of calibration of the engineering model of SXT (EM), and project the quality of the flight mirrors.

  5. Soft X-ray FEL simulation in PAL-XFEL

    NASA Astrophysics Data System (ADS)

    Shim, Chi Hyun; Ko, In Soo; Parc, Yong Woon; Han, Jang Hui

    2015-10-01

    The soft X-ray beamline in the Pohang Accelerator Laboratory X-ray Free Electron Laser (PAL-XFEL) will provide a photon beam with a wavelength from 1 nm to 3 nm in the self-amplified spontaneous emission (SASE) mode by using an electron beam with a 3.15-GeV beam energy. Linearly polarized radiation will be supplied by using six planar undulators (PUs). The linearly-polarized radiation powers at 1 (3) nm can reach 10.2 (30) GW. Polarization of the radiation will be controlled by applying the reverse undulator tapering scheme to the PUs and adding two helical undulators (HUs). The circularly-polarized radiation powers at 1 (3) nm will be 3.11 (11.73) GW. The degrees of circular polarization will be larger than 0.99 for both wavelengths. Three options for the future upgrade of the beamline to increase the radiation power are proposed.

  6. Soft X-ray spectroscopy of solar flares - An overview

    NASA Technical Reports Server (NTRS)

    Doschek, G. A.

    1990-01-01

    An overview of the current status of high spectral resolution soft X-ray observations of solar flares is given. The review concentrates primarily on recent results and interpretations of results obtained from orbiting Bragg crystal spectrometers flow during the last solar maximum on the US DoD P78-1 spacecraft, the NASA SMM, and the ISAS Hinotori spacecraft. Results and several key issues regarding interpretation of the spectra are presented. Specifically, the dynamics of coronal flare plasmas as revealed by X-ray line profiles and wavelength shifts are discussed. Recent results concerning the theory of chromospheric evaporation are given. The temperature of coronal flare plasma is discussed within the context of a differential mission measure. Results concerning electron density measurements, nonequilibrium processes, and relative element abundances are also reviewed.

  7. Goldhelox: a soft x-ray solar telescope.

    PubMed

    Durfee, D S; Moody, J W; Brady, K D; Brown, C; Campbell, B; Durfee, M K; Early, D; Hansen, E; Madsen, D W; Morey, D B; Roming, P W; Savage, M B; Eastman, P F; Jensen, V

    1995-01-01

    The Goldhelox Project is the construction and use of a near-normal incidence soft x-ray robotic solar telescope by undergraduate students at Brigham Young University. Once it is completed and tested, it will be deployed from a Get-Away-Special (GAS) canister in the bay of a space shuttle. It will image the sun at a wavelength of 171-181Å with a time resolution of 1 sec and a spatial resolution of 2.5 arcsec. The observational bandpass was chosen to image x-rays from highly ionized coronal Fe lines. The data will be an aid in better understanding the beginning phases of solar flares and how flaring relates to the physics of the corona-chromosphere transition region. Goldhelox is tentatively scheduled to fly on a space shuttle sometime in 1995 or 1996. This paper outlines the project goals, basic instrument design, and the unique aspects of making this an undergraduate endeavor. PMID:21307474

  8. Disentangling AGN and Star Formation in Soft X-Rays

    NASA Technical Reports Server (NTRS)

    LaMassa, Stephanie M.; Heckman, T. M.; Ptak, A.

    2012-01-01

    We have explored the interplay of star formation and active galactic nucleus (AGN) activity in soft X-rays (0.5-2 keV) in two samples of Seyfert 2 galaxies (Sy2s). Using a combination of low-resolution CCD spectra from Chandra and XMM-Newton, we modeled the soft emission of 34 Sy2s using power-law and thermal models. For the 11 sources with high signal-to-noise Chandra imaging of the diffuse host galaxy emission, we estimate the luminosity due to star formation by removing the AGN, fitting the residual emission. The AGN and star formation contributions to the soft X-ray luminosity (i.e., L(sub x,AGN) and L(sub x,SF)) for the remaining 24 Sy2s were estimated from the power-law and thermal luminosities derived from spectral fitting. These luminosities were scaled based on a template derived from XSINGS analysis of normal star-forming galaxies. To account for errors in the luminosities derived from spectral fitting and the spread in the scaling factor, we estimated L(sub x,AGN) and L(sub x,SF))from Monte Carlo simulations. These simulated luminosities agree with L(sub x,AGN) and L(sub x,SF) derived from Chandra imaging analysis within a 3sigma confidence level. Using the infrared [Ne ii]12.8 micron and [O iv]26 micron lines as a proxy of star formation and AGN activity, respectively, we independently disentangle the contributions of these two processes to the total soft X-ray emission. This decomposition generally agrees with L(sub x,SF) and L(sub x,AGN) at the 3 sigma level. In the absence of resolvable nuclear emission, our decomposition method provides a reasonable estimate of emission due to star formation in galaxies hosting type 2 AGNs.

  9. DISENTANGLING AGN AND STAR FORMATION IN SOFT X-RAYS

    SciTech Connect

    LaMassa, Stephanie M.; Heckman, T. M.; Ptak, A.

    2012-10-20

    We have explored the interplay of star formation and active galactic nucleus (AGN) activity in soft X-rays (0.5-2 keV) in two samples of Seyfert 2 galaxies (Sy2s). Using a combination of low-resolution CCD spectra from Chandra and XMM-Newton, we modeled the soft emission of 34 Sy2s using power-law and thermal models. For the 11 sources with high signal-to-noise Chandra imaging of the diffuse host galaxy emission, we estimate the luminosity due to star formation by removing the AGN, fitting the residual emission. The AGN and star formation contributions to the soft X-ray luminosity (i.e., L{sub x,AGN} and L{sub x,SF}) for the remaining 24 Sy2s were estimated from the power-law and thermal luminosities derived from spectral fitting. These luminosities were scaled based on a template derived from XSINGS analysis of normal star-forming galaxies. To account for errors in the luminosities derived from spectral fitting and the spread in the scaling factor, we estimated L{sub x,AGN} and L{sub x,SF} from Monte Carlo simulations. These simulated luminosities agree with L{sub x,AGN} and L{sub x,SF} derived from Chandra imaging analysis within a 3{sigma} confidence level. Using the infrared [Ne II]12.8 {mu}m and [O IV]26 {mu}m lines as a proxy of star formation and AGN activity, respectively, we independently disentangle the contributions of these two processes to the total soft X-ray emission. This decomposition generally agrees with L{sub x,SF} and L{sub x,AGN} at the 3{sigma} level. In the absence of resolvable nuclear emission, our decomposition method provides a reasonable estimate of emission due to star formation in galaxies hosting type 2 AGNs.

  10. Characterizing automotive fuel cell materials by soft x-ray scanning transmission x-ray microscopy

    NASA Astrophysics Data System (ADS)

    Hitchcock, A. P.; Lee, V.; Wu, J.; West, M. M.; Cooper, G.; Berejnov, V.; Soboleva, T.; Susac, D.; Stumper, J.

    2016-01-01

    Proton-Exchange Membrane Fuel Cell (PEM-FC) based engines are being developed rapidly for near-term implementation in hydrogen fueled, mass production, personal automobiles. Research is focused on understanding and controlling various degradation processes (carbon corrosion, Pt migration, cold start), and reducing cost by reducing or eliminating Pt catalyst. We are using soft X-ray scanning transmission X-ray microscopy (STXM) at the S 2p, C 1s, O 1s and F 1s edges to study a variety of issues related to optimization of PEM-FC materials for automotive applications. A method to efficiently and accurately measure perfluorosulfonic acid distributions was developed and is being used to better understand how different loadings and preparation methods affect the ionomer distribution in the cathode. Progress towards an environmental cell capable of controlling the temperature and humidity of a PEM-FC sample in the STXM is described. Methods for studying the 3D chemical structure of PEM-FC are outlined.

  11. Soft x-ray resist characterization: Studies with a laser plasma x-ray source

    SciTech Connect

    Kubiak, G.D.; Outka, D.A. ); Zeigler, J.M. )

    1990-01-01

    Little work has been performed to characterize the exposure sensitivity, contrast, and tone of candidate resists for photon energies between 100--300 eV, the range in which projection soft x-ray lithography will be developed. We report here the characterization of near-edge x-ray absorption fine structure (NEXAFS) spectra, exposure sensitivity, contrast, and post-exposure processing of selected polysilane resists at photon energies close to the Si L{sub 2,3} absorption edge (100 eV). We find absorption resonance features in the NEXAFS spectra which we assign to excitation into Si--Si and Si--C {sigma}* orbitals. Using monochromatized XUV exposures on the Si--Si {sigma}* resonance at 105 eV, followed by solvent dissolution development, we have measured the exposure sensitivity curves of these resists. We find sensitivities in the range of 600--3000 mJ/cm{sup 2} and contrasts in the range from 0.5--1.4, depending on the polysilane side chain. We have also performed exposure sensitivity measurements at 92 eV, below the edge. Sensitivity decreases slightly compared to 105 eV exposures and the saturation depth and contrast both increase, as expected. We find also that exposing resist films to oxygen after XUV exposure, but before development increases the sensitivity markedly. 7 figs.

  12. 2D X-ray scanner and its uses in laboratory reservoir characterization measurements

    SciTech Connect

    Maloney, D.; Doggett, K.

    1997-08-01

    X-ray techniques are used in petroleum laboratories for a variety of reservoir characterization measurements. This paper describes the configuration of a 2D X-ray scanner and many of the ways in which it simplifies and improves accuracy`s of laboratory measurements. Linear X-ray scanners are most often used to provide descriptions of fluid saturations within core plugs during flow tests. We configured our linear scanner for both horizontal and vertical movement. Samples can be scanned horizontally, vertically, or according to horizontal and vertical grids. X-ray measurements are fast, allowing measurements of two- and three-phase fluid saturations during both steady- and unsteady-state flow processes. Rock samples can be scanned while they are subjected to stress, pore pressure, and temperature conditions simulating those of a petroleum reservoir. Many types of measurements are possible by selecting appropriate X-ray power settings, dopes, filters, and collimator configurations. The scanner has been used for a variety of applications besides fluid saturation measurements. It is useful for measuring porosity distributions in rocks, concentrations of X-ray dopes within flow streams during tracer tests, gap widths in fracture flow cells, fluid interface levels in PVT cells and fluid separators, and other features and phenomena.

  13. Heliospheric X-Rays and the 1/4 keV Soft X-Ray Background Map

    NASA Astrophysics Data System (ADS)

    Robertson, I. P.; Cravens, T. E.; Snowden, S. L.

    2003-12-01

    X-rays are generated throughout the heliosphere as a consequence of charge transfer collisions between heavy solar wind ions and interstellar neutrals. The high charge state solar wind ions resulting from these collisions are left in highly excited states and emit extreme ultraviolet or soft x-ray photons. X-rays are also generated because of charge transfer collisions with neutral hydrogen in the Earth's geocorona. Our model simulates this charge transfer mechanism. It uses the Fahr hot model to determine spatial variations of interstellar helium and hydrogen densities. It also uses published terrestrial exospheric hydrogen distributions and solar wind speed, density and temperature distributions to determine x-ray intensities due to charge transfer with geocoronal hydrogen. We used the same viewing conditions as Snowden [1995] for the 1/4 keV channel soft x-ray background map in galactic coordinates, and produce an analogous heliospheric/geocoronal x-ray intensity map. Our preliminary conclusion is that roughly 50% of the total background soft x-ray intensity in the galactic plane and 25% at high galactic latitudes can be attributed to the charge transfer process operating within the solar system, with the remaining emission coming from outside our heliosphere.

  14. A wide-field soft X-ray camera

    NASA Technical Reports Server (NTRS)

    Petre, R.

    1981-01-01

    A wide-field soft X-ray camera (WFSXC) sensitive in the 50 to 250 eV band is described. The camera features Wolter-Schwarzschild optics with an 8 degree field of view and 300 cu cu collecting area. The focal plane instrument is a microchannel plate detector. Broad-band energy discrimination is provided by thin-film filters mounted immediately in front of the focal plane. The WFSXC is capable of detecting sources with intensities greater than 5 percent of HZ 43 during typical sounding rocket exposures, and it would approach the same sensitivity range as EUVE during a typical exposure from the Shuttle.

  15. Advanced laser driver for soft x-ray projection lithography

    SciTech Connect

    Zapata, L.E.; Beach, R.J.; Dane, C.B.; Reichert, P.; Honig, J.N.; Hackel, L.A.

    1994-03-01

    A diode-pumped Nd:YAG laser for use as a driver for a soft x-ray projection lithography system is described. The laser will output 0.5 to 1 J per pulse with about 5 ns pulse width at up to 1.5 kHz repetition frequency. The design employs microchannel-cooled diode laser arrays for optical pumping, zigzag slab energy storage, and a single frequency oscillator injected regenerative amplifier cavity using phase conjugator beam correction for near diffraction limited beam quality. The design and initial results of this laser`s activation experiments will be presented.

  16. Soft X-ray microscopy to characterize polyelectrolyte assemblies.

    PubMed

    Köhler, Karen; Déjugnat, Christophe; Dubois, Monique; Zemb, Thomas; Sukhorukov, Gleb B; Guttmann, Peter; Möhwald, Helmuth

    2007-07-26

    Transmission microscopy with soft X-rays (TXM) is applied to image in-situ polyelectrolyte assemblies in aqueous environment. The method is element specific and at this stage exhibits a lateral resolution of 20 nm. With the specific examples of hollow capsules and full spheres made of PAH/PSS polyelectrolyte multilayers, it is shown quantitatively that heat treatment irreversibly reduces the water content in the membrane. These experiments complement those reported recently on the polyion system PDADMAC/PSS, which shows a different glass-transition behavior. Finally, the potential and present limitations of TXM are discussed. PMID:17428089

  17. Imaging the Magnetosphere in Soft X-Rays

    NASA Astrophysics Data System (ADS)

    Sibeck, David; Connor, Hyunju K.; Collier, MIchael; Kuntz, Kip

    2015-04-01

    The charge exchange that occurs when high charge state solar wind ions encounter exospheric neutrals in the Earth's magnetosheath and cusps results in the emission of soft (0.1 to 1 keV) x-rays that have been observed by a number of astrophysics telescopes with narrow fields of view. A global imager would be able to visualize and diagnose the state of the solar wind-magnetosphere interaction, including the characteristics of reconnection on the dayside magnetopause. This talk presents our current efforts to develop such an imager, including both hardware and simulations of the expected signatures.

  18. Soft X-ray Microscopy of Green Cements

    NASA Astrophysics Data System (ADS)

    Monteiro, P. J. M.; Mancio, M.; Kirchheim, A. P.; Chae, R.; Ha, J.; Fischer, P.; Tyliszczak, T.

    2011-09-01

    The present status of the cement and concrete industry is not sustainable. The production of Portland cement is responsible for 7% of the CO2 emissions in the world and existing reinforced concrete infrastructure is deteriorating at a fast pace. The change in the existing technology requires new developments in our understanding of the nanostructure of hydration products and the complex deterioration reactions. We have been developing an elaborate research program to advance the existing cement and concrete science by characterizing its nanostructure by synchrotron radiation. A new generation of green cements is being studied using high-resolution soft x-ray microscopy at the nano-level.

  19. Soft X-ray Microscopy of Green Cements

    SciTech Connect

    Monteiro, P. J. M.; Mancio, M.; Chae, R.; Ha, J.; Kirchheim, A. P.; Fischer, P.; Tyliszczak, T.

    2011-09-09

    The present status of the cement and concrete industry is not sustainable. The production of Portland cement is responsible for 7% of the CO{sub 2} emissions in the world and existing reinforced concrete infrastructure is deteriorating at a fast pace. The change in the existing technology requires new developments in our understanding of the nanostructure of hydration products and the complex deterioration reactions. We have been developing an elaborate research program to advance the existing cement and concrete science by characterizing its nanostructure by synchrotron radiation. A new generation of green cements is being studied using high-resolution soft x-ray microscopy at the nano-level.

  20. OSO-8 soft X-ray wheel experiment: Data analysis

    NASA Technical Reports Server (NTRS)

    Kraushaar, W. L.

    1982-01-01

    The soft X-ray experiment hardware and its operation are described. The device included six X-ray proportional counters, two of which, numbers 1 and 4, were pressurized with on-board methane gas supplies. Number 4 developed an excessive leak rate early in the mission and was turned off on 1975 day number 282 except for brief (typically 2-hour) periods up to day 585 after which it as left off. Counter 1 worked satisfactorily until 1975 day number 1095 (January 1, 1978) at which time the on-board methane supply was depleted. The other four counters were sealed and all except number 3 worked satisfactorily throughout the mission which terminated with permanent satellie shut-down on day 1369. This was the first large area thin-window, gas-flow X-ray detector to be flown in orbit. The background problems were severe and consumed a very large portion of the data analysis effort. These background problems were associated with the Earth's trapped electron belts.

  1. OSO-8 soft X-ray wheel experiment: Data analysis

    NASA Astrophysics Data System (ADS)

    Kraushaar, W. L.

    The soft X-ray experiment hardware and its operation are described. The device included six X-ray proportional counters, two of which, numbers 1 and 4, were pressurized with on-board methane gas supplies. Number 4 developed an excessive leak rate early in the mission and was turned off on 1975 day number 282 except for brief (typically 2-hour) periods up to day 585 after which it as left off. Counter 1 worked satisfactorily until 1975 day number 1095 (January 1, 1978) at which time the on-board methane supply was depleted. The other four counters were sealed and all except number 3 worked satisfactorily throughout the mission which terminated with permanent satellie shut-down on day 1369. This was the first large area thin-window, gas-flow X-ray detector to be flown in orbit. The background problems were severe and consumed a very large portion of the data analysis effort. These background problems were associated with the Earth's trapped electron belts.

  2. The Astro-H Soft X-ray Spectrometer (SXS)

    NASA Astrophysics Data System (ADS)

    Porter, F. Scott; Fujimoto, Ryuichi; Kelley, Richard L.; Kilbourne, Caroline A.; Mitsuda, Kazuhiasa; Ohashi, Takaya; Astro-H/SXS Collaboration

    2009-12-01

    The Soft-X-ray Spectrometer (SXS) is a high spectral resolution, cryogenic x-ray spectrometer that will fly on the Japan/U.S. Astro-H observatory in 2014. The SXS is composed of a 36 pixel, imaging, x-ray calorimeter array that will operate at 0.05 K utilizing a 2-stage adiabatic demagnetization refrigerator and a redundant pre-cooler design using both a 40 liter liquid helium tank and a 1.7 K Joule-Thomson (JT) cryocooler. Additional redundant Stirling cycle coolers provide pre-cooling for the (JT) and cool the outer thermal shields for the JT and the helium tank. The detector system, while similar to that flown on Suzaku, is composed of larger 0.81×0.81mm pixels, but has significantly better performance, currently predicted to be better than 4 eV FWHM at 6 keV with 95% quantum efficiency. This instrument is the result of a close collaboration between many institutions in the U.S. and Japan over the last 25 years. Here we will present an overview of the SXS instrument, the SXS cooling system, and recent laboratory improvements to the detector system.

  3. The Astro-H Soft X-ray Spectrometer (SXS)

    SciTech Connect

    Porter, F. Scott; Kelley, Richard L.; Kilbourne, Caroline A.; Fujimoto, Ryuichi; Mitsuda, Kazuhiasa; Ohashi, Takaya

    2009-12-16

    The Soft-X-ray Spectrometer (SXS) is a high spectral resolution, cryogenic x-ray spectrometer that will fly on the Japan/U.S. Astro-H observatory in 2014. The SXS is composed of a 36 pixel, imaging, x-ray calorimeter array that will operate at 0.05 K utilizing a 2-stage adiabatic demagnetization refrigerator and a redundant pre-cooler design using both a 40 liter liquid helium tank and a 1.7 K Joule-Thomson (JT) cryocooler. Additional redundant Stirling cycle coolers provide pre-cooling for the (JT) and cool the outer thermal shields for the JT and the helium tank. The detector system, while similar to that flown on Suzaku, is composed of larger 0.81x0.81mm pixels, but has significantly better performance, currently predicted to be better than 4 eV FWHM at 6 keV with 95% quantum efficiency. This instrument is the result of a close collaboration between many institutions in the U.S. and Japan over the last 25 years. Here we will present an overview of the SXS instrument, the SXS cooling system, and recent laboratory improvements to the detector system.0.

  4. Synoptic IPS and Yohkoh soft X-ray observations

    NASA Technical Reports Server (NTRS)

    Hick, P.; Jackson, B. V.; Rappoport, S.; Woan, G.; Slater, G.; Strong, K.; Uchida, Y.

    1995-01-01

    Interplanetary scintillation measurements of the disturbance factor, g, from October 1991 to October 1992 are used to construct synoptic Carrington maps. These maps, which show the structure of the quiet solar wind, are compared with X-ray Carrington maps from the Yohkoh Soft X-ray Telescope (SXT) instrument. For the period studied the global structure outlined by (weakly) enhanced g-values apparent in the interplanetary scintillation (IPS) maps tend to match the active regions (as shown in the X-ray maps) significantly better than the heliospheric current sheet. Contrary to traditional opinion, which views active regions as magnetically closed structures that do not have any significant impact on the solar wind flow, our results suggest that density fluctuations in the solar wind are significantly enhanced over active regions. These results support the suggestion by Uchida et al. (1992), based on Yohkoh observations of expanding active regions, that active regions play a role in feeding mass into the quiet solar wind.

  5. The Astro-H Soft X-Ray Mirror

    NASA Technical Reports Server (NTRS)

    Robinson, David; Okajima, Takashi; Serlemitsos, Peter; Soong, Yang

    2012-01-01

    The Astro-H is led by the Japanese Space Agency (JAXA) in collaboration with many other institutions including the NASA Goddard Space Flight Center. Goddard's contributions include two soft X-ray telescopes (SXTs). The telescopes have an effective area of 562 square cm at 1 keV and 425 square cm at 6 keV with an image quality requirement of 1.7 arc-minutes half power diameter (HPD). The engineering model has demonstrated 1.1 arc-minutes HPD error. The design of the SXT is based on the successful Suzaku mission mirrors with some enhancements to improve the image quality. Two major enhancements are bonding the X-ray mirror foils to alignment bars instead of allowing the mirrors to float, and fabricating alignment bars with grooves within 5 microns of accuracy. An engineering model SXT was recently built and subjected to several tests including vibration, thermal, and X-ray performance in a beamline. Several lessons were learned during this testing that will be incorporated in the flight design. Test results and optical performance are discussed, along with a description of the design of the SXT.

  6. Multi-tens of GW peak power plasma-based soft x-ray laser

    NASA Astrophysics Data System (ADS)

    Oliva, E.; Fajardo, M.; Li, L.; Le, T. T. T.; Ros, D.; Sebban, S.; Velarde, P.; Zeitoun, P.

    2013-09-01

    Ultra-intense X-ray sources have opened new avenues by creating new states of matter or probing and imaging living or inert matter. Free-electron lasers have a strong leadership by delivering pulses combining femtosecond duration and 10s of microJoules to milliJoule energy. However, these sources remain highly expensive limiting their number to a few worldwide. In parallel, laser-pumped soft X-ray lasers hold outstanding promises having demonstrated the most energetic monochromatic soft x-ray pulse and being intrinsically fully synchronized with any secondary source of the pump laser. Since the first successful demonstration of amplification of a high harmonic pulse in a plasma from gas in 2003 and from solid in 2008, we have developed an extensive numerical study. 2D hydrodynamic simulations showed that optimized Transient Collisional Excitation plasma amplifiers, may store up to 0.4 mJ in the population inversion. If carefully seeded, pulses of 80 fs and 20 μJ might be generated with table-top lasers (10J). As the energy extracted is far from the milliJoule requirements of most exciting applications, we studied the seminal experiment of Ditmire et al who seeded a plasma emitting milliJoules in the form of Amplified Spontaneous Emission (ASE).We retrieved and explained for the first time the experimental result (ASE 1,000 times stronger than amplified seed). We thus proposed and fully modeled the transposition of the so-called Chirped Pulse Amplification (CPA) in the soft X-ray range, showing that 6 mJ, 200 fs, fully coherent soft X-ray pulse is accessible with compact pump lasers.

  7. Soft X-Ray and Vacuum Ultraviolet Based Spectroscopy of the Actinides

    SciTech Connect

    Tobin, J G

    2011-03-17

    The subjects of discussion included: VUV photoelectron spectroscopy, X-ray photoelectron spectroscopy, Synchrotron-radiation-based photoelectron spectroscopy, Soft x-ray absorption spectroscopy, Soft x-ray emission spectroscopy, Inverse photoelectron spectroscopy, Bremstrahlung Isochromat Spectroscopy, Low energy IPES, Resonant inverse photoelectron spectroscopy.

  8. Molecular orientation in soft matter thin films studied by resonant soft X-ray reflectivity

    SciTech Connect

    Mezger, Markus; Jerome, Blandine; Kortright, Jeffrey B.; Valvidares, Manuel; Gullikson, Eric; Giglia, Angelo; Mahne, Nicola; Nannarone, Stefano

    2011-01-12

    We present a technique to study depth profiles of molecular orientation in soft matter thin films with nanometer resolution. The method is based on dichroism in resonant soft X-ray reflectivity using linear s- and p-polarization. It combines the chemical sensitivity of Near-Edge X-ray Absorption Fine Structure spectroscopy to specific molecular bonds and their orientation relative to the polarization of the incident beam with the precise depth profiling capability of X-ray reflectivity. We demonstrate these capabilities on side chain liquid crystalline polymer thin films with soft X-ray reflectivity data at the carbon K edge. Optical constants of the anisotropic refractive index ellipsoid were obtained from a quantitative analysis using the Berreman formalism. For films up to 50 nm thickness we find that the degree of orientation of the long axis exhibits no depth variation and isindependent of the film thickness.

  9. Gain dynamics in a soft X-ray laser ampli er perturbed by a strong injected X-ray eld

    SciTech Connect

    Wang, Yong; Wang, Shoujun; Oliva, E; Lu, L; Berrill, Mark A; Yin, Liang; Nejdl, J; Luther, Brad; Proux, C; Le, T. T.; Dunn, James; Ros, D; Zeitoun, Philippe; Rocca, Jorge

    2014-01-01

    Seeding soft X-ray plasma ampli ers with high harmonics has been demonstrated to generate high-brightness soft X-ray laser pulses with full spatial and temporal coherence. The interaction between the injected coherent eld and the swept-gain medium has been modelled. However, no exper- iment has been conducted to probe the gain dynamics when perturbed by a strong external seed eld. Here, we report the rst X-ray pump X-ray probe measurement of the nonlinear response of a plasma ampli er perturbed by a strong soft X-ray ultra-short pulse. We injected a sequence of two time-delayed high-harmonic pulses (l518.9 nm) into a collisionally excited nickel-like molybdenum plasma to measure with femto-second resolution the gain depletion induced by the saturated ampli cation of the high-harmonic pump and its subsequent recovery. The measured fast gain recovery in 1.5 1.75 ps con rms the possibility to generate ultra-intense, fully phase-coherent soft X-ray lasers by chirped pulse ampli cation in plasma ampli ers.

  10. UV and Soft X-ray Polar Coronal Jets

    NASA Astrophysics Data System (ADS)

    Dobrzycka, D.; Raymond, J. C.; Cranmer, S. R.; Li, J.

    2002-01-01

    Coronal jets are spectacular dynamic events originating from different structures in the solar corona. Jetlike phenomena were observed by various instruments aboard SOHO, and the X--ray jets were discovered by Yohkoh's soft X--ray telescope (SXT). The relation among the different types of jets is still not yet clear. We present ultraviolet spectroscopy of polar coronal jets obtained by the Ultraviolet Coronagraph Spectrometer (UVCS/SOHO) at heights in the corona ranging from 1.5 Rodot to 2.5 Rodot. The jets appear to originate near flaring ultraviolet bright points within polar coronal holes and were recorded by UVCS as a significant enhancement in the integrated intensities of the strongest coronal emission lines: mainly H I Ly alpha and O VI lambda lambda 1032,1037. A number of the detected jets are correlated with EIT Fe XII 195Å and LASCO C2 white-light events. Our modeling of the jet's observable properties provided estimates of the jet plasma conditions, as well as the initial electron temperature and heating rate required to reproduce the observed O VI ionization state. We discuss possible relationship between the polar ultraviolet and X--ray jets based on the results of coordinated SXT and UVCS observations in December 1996. We compare their properties and consider the magnetic reconnection models, developed for X--ray jets, as a model for UV jet formation. This work is supported by the National Aeronautics and Space Administration under grant NAG5--10093 to the Smithsonian Astrophysical Observatory, by Agenzia Spaziale Italiana, and by the ESA PRODEX program (Swiss contribution).

  11. Applications of soft x-ray magnetic dichroism

    NASA Astrophysics Data System (ADS)

    van der Laan, G.

    2013-04-01

    Applications of x-ray magnetic circular and linear dichroism (XMCD and XMLD) are reviewed in the soft x-ray region, covering the photon energy range 0.4-2 keV, which includes important absorption edges such as the 3d transition metal L2,3 and rare earth M4,5. These techniques enable a broad range of novel and exciting studies such as on the electronic properties and magnetic ordering of novel nanostructured systems. XMCD has a sensitivity better than 0.01 monolayer (at the surface) and due to simple detection methods, such as electron yield and fluorescence yield, it has become a workhorse technique in physics and materials science. It is the only element-specific technique able to distinguish between the spin and orbital parts of the magnetic moments. The applications are vast, e.g., in x-ray holographic imaging, XMCD gives a spatial resolution of tens of nm. While many studies in the past were centered on physics, more recently new applications have emerged in areas such as chemistry, biology and earth and environmental sciences. For instance, XMCD allows the determination of the cation occupations in spinels and other ternary oxides. In scanning transmission x-ray microscopy (STXM), XMCD enables us to map biogenic magnetite redox changes resulting in a surprising degree of variation on the nanoscale. Another recent development is ferromagnetic resonance (FMR) detected by time-resolved XMCD which opens the door to element-, site- and layer-specific dynamical measurements. By exploiting the time structure of the pulsed synchrotron radiation from the storage ring the relative phase of precession in the individual magnetic layers of a multilayer stack can be determined.

  12. Opening the Field of Soft X-ray Polarimetry

    NASA Astrophysics Data System (ADS)

    Marshall, Herman L.; Schulz, Norbert; Windt, David; Gullikson, Eric

    2015-08-01

    We present development of a telescope for measuring linear X-ray polarization over the 0.2-0.8 keV band. We employ multilayer-coated mirrors as Bragg reflectors at the Brewster angle. By matching to the dispersion of a spectrometer, one may take advantage of high multilayer reflectivities and achieve polarization modulation factors over 90%. We have constructed a source of polarized X-rays that operates at a wide range of energies with a selectable polarization angle. Previously, we demonstrated that the polarimetry beam-line provides 100% polarized X-rays at 0.525 keV (Marshall et al. 2013). Recently, we upgraded the source by installing a mirror with a laterally graded multilayer (LGML) coating, providing a wide energy range. Here, we will present results from continued development that includes LGMls of new material combinations (C/CrCo and La/B4C) with high efficiencies in different soft X-ray bands. We have also sponsored the development of new gratings and anticipate showing results from testing these new gratings. Finally, we will present a design for a small telescope for suborbital or orbital missions. A suborbital mission would be limited to measuring the polarization of a blazar such as Mk 421 to a few percent while an orbital version could measure the polarizations of neutron stars, active galactic nuclei, and blazars.Support for this work was provided by the National Aeronautics and Space Administration through grant NNX12AH12G and by Research Investment Grants from the MIT Kavli Institute.

  13. Coherent X-ray diffraction from collagenous soft tissues

    PubMed Central

    Berenguer de la Cuesta, Felisa; Wenger, Marco P. E.; Bean, Richard J.; Bozec, Laurent; Horton, Michael A.; Robinson, Ian K.

    2009-01-01

    Coherent X-ray diffraction has been applied in the imaging of inorganic materials with great success. However, its application to biological specimens has been limited to some notable exceptions, due to the induced radiation damage and the extended nature of biological samples, the last limiting the application of most part of the phasing algorithms. X-ray ptychography, still under development, is a good candidate to overcome such difficulties and become a powerful imaging method for biology. We describe herein the feasibility of applying ptychography to the imaging of biological specimens, in particular collagen rich samples. We report here speckles in diffraction patterns from soft animal tissue, obtained with an optimized small angle X-ray setup that exploits the natural coherence of the beam. By phasing these patterns, dark field images of collagen within tendon, skin, bone, or cornea will eventually be obtained with a resolution of 60–70 nm. We present simulations of the contrast mechanism in collagen based on atomic force microscope images of the samples. Simulations confirmed the ‘speckled’ nature of the obtained diffraction patterns. Once inverted, the patterns will show the disposition and orientation of the fibers within the tissue, by enhancing the phase contrast between protein and no protein regions of the sample. Our work affords the application of the most innovative coherent X-ray diffraction tools to the study of biological specimens, and this approach will have a significant impact in biology and medicine because it overcomes many of the limits of current microscopy techniques. PMID:19706395

  14. Dual-energy x-ray absorptiometry using 2D digital radiography detector: application to bone densitometry

    NASA Astrophysics Data System (ADS)

    Dinten, Jean-Marc; Robert-Coutant, Christine; Darboux, Michel

    2001-06-01

    Dual Energy X-Rays Absorptiometry (DXA) is commonly used to separate soft tissues and bone contributions in radiographs. This decomposition leads to bone mineral density (BMD) measurement. Most clinical systems use pencil or fan collimated X-Rays beam with mono detectors or linear arrays. On these systems BMD is computed from bi-dimensional (2D) images obtained by scanning. Our objective is to take advantage of the newly available flat panels detectors and to propose a DXA approach without scanning, based on the use of cone beam X-Rays associated with a 2D detector. This approach yields bone densitometry systems with an equal X and Y resolution, a fast acquisition and a reduced risk of patient motion.Scatter in this case becomes an important issue. While scattering is insignificant on collimated systems, its level and geometrical structure may severely alter BMD measurement on cone beam systems. In our presentation an original DXA method taking into account scattering is proposed. This new approach leads to accurate BMD values.In order to evaluate the accuracy of our new approach, a phantom representative of the spine regions tissue composition (bone, fat , muscle) has been designed. The comparison between the expected theoretical and the reconstructed BMD values validates the accuracy of our method. Results on anthropomorphic spine and hip regions are also presented.

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

    NASA Technical Reports Server (NTRS)

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

    1987-01-01

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

  16. Observing soft X-ray line emission from the interstellar medium with X-ray calorimeter on a sounding rocket

    NASA Technical Reports Server (NTRS)

    Zhang, J.; Edwards, B.; Juda, M.; Mccammon, D.; Skinner, M.; Kelley, R.; Moseley, H.; Schoelkopf, R.; Szymkowiak, A.

    1990-01-01

    For an X-ray calorimeter working at 0.1 K, the energy resolution ideally can be as good as one eV for a practical detector. A detector with a resolution of 17 eV FWHM at 6 keV has been constructed. It is expected that this can be improved by a factor of two or more. With X-ray calorimeters flown on a sounding rocket, it should be possible to observe soft X-ray line emission from the interstellar medium over the energy range 0.07 to 1 keV. Here, a preliminary design for an X-ray calorimeter rocket experiment and the spectrum which might be observed from an equilibrium plasma are presented. For later X-ray calorimeter sounding rocket experiments, it is planned to add an aluminum foil mirror with collecting area of about 400 sq cm to observe line features from bright supernova remnants.

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

    NASA Technical Reports Server (NTRS)

    Espy, Samuel L.

    1994-01-01

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

  18. Imaging bacterial spores by soft-x-ray microscopy

    SciTech Connect

    Stead, A.D.; Ford, T.W.; Judge, J.

    1997-04-01

    Bacterial spores are able to survive dehydration, but neither the physiological nor structural basis of this have been fully elucidated. Furthermore, once hydrated, spores often require activation before they will germinate. Several treatments can be used to activate spores, but in the case of Bacillus subtlis the most effective is heat treatment. The physiological mechanism associated with activation is also not understood, but some workers suggest that the loss of calcium from the spores may be critical. However, just prior to germination, the spores change from being phase bright to phase dark when viewed by light microscopy. Imaging spores by soft x-ray microscopy is possible without fixation. Thus, in contrast to electron microscopy, it is possible to compare the structure of dehydrated and hydrated spores in a manner not possible previously. A further advantage is that it is possible to monitor individual spores by phase contrast light microscopy immediately prior to imaging with soft x-rays; whereas, with both electron microscopy and biochemical studies, it is a population of spores being studied without knowledge of the phase characteristics of individual spores. This study has therefore tried to compare dehydrated and hydrated spores and to determine if there is a mass loss from individual spores as they pass the transition from being phase bright to phase dark.

  19. Soft x-ray yield from NX2 plasma focus

    SciTech Connect

    Lee, S.; Rawat, R. S.; Lee, P.; Saw, S. H.

    2009-07-15

    The Lee model code is used to compute neon soft x-ray yield Y{sub sxr} for the NX2 plasma focus as a function of pressure. Comparison with measured Y{sub sxr} shows reasonable agreement in the Y{sub sxr} versus pressure curve, the absolute maximum yield as well as the optimum pressure. This gives confidence that the code gives a good representation of the neon plasma focus in terms of gross properties including speeds and trajectories and soft x-ray yields, despite its lack of modeling localized regions of higher densities and temperatures. Computed current curves versus pressure are presented and discussed particularly in terms of the dynamic resistance of the axial phase. Computed gross properties of the plasma focus including peak discharge current I{sub peak}, pinch current I{sub pinch}, minimum pinch radius r{sub min}, plasma density at the middle duration of pinch n{sub pinch}, and plasma temperature at middle duration of pinch T{sub pinch} are presented and the trends in variation of these are discussed to explain the peaking of Y{sub sxr} at optimum pressure.

  20. Time-resolved measurement of x-ray heating in plastic foils irradiated by intense soft-x-ray pulses

    SciTech Connect

    Edwards, J.; Dunne, M.; Riley, D.; Taylor, R.; Willi, O. ); Rose, S.J. )

    1991-12-30

    Intense, soft-x-ray pulses, generated from separate laser-irradiated converters, were used to irradiate plane plastic foils. The x-ray heating was investigated by measuring the temperature histories of chlorinated tracer layers buried at different depths in the targets. The temperature diagonistic was a time-resolved extreme-UV absorption spectroscopy technique using chlorine {ital L}-shell transitions. The temporal temperature profiles were reasonably well reproduced by radiation-hydrocode simulations.

  1. Soft X-ray observation of the Rho Ophiuchus dark cloud region

    NASA Technical Reports Server (NTRS)

    Apparao, K. M. V.; Hayakawa, S.; Hearn, D. R.

    1979-01-01

    Soft X-rays (0.1-0.8 keV) from the region including the Rho Oph dark cloud were observed with the SAS-3 low-energy X-ray telescope. No X-ray absorption by the cloud was observed. This indicates that the diffuse component of soft X-rays in this region is mostly from the foreground of the Rho Oph cloud which is located at a distance of 160-200 pc.

  2. X-ray/UV variability and the origin of soft X-ray excess emission from II Zw 177

    NASA Astrophysics Data System (ADS)

    Pal, Main

    We study a detailed broad-band X-ray/UV emission from the narrow line Seyfert 1 galaxy II Zw 177 based on two XMM-Newton and single Swift/XRT observations. Both XMM-Newton observations show the soft X-ray excess emission below 2 keV when the best-fit 2 - 10 keV power law is extrapolated down to 0.3 keV. We find the blurred reflection from an ionized accretion disc and Comptonized disc emission both describe the observed soft excess well. We find a remarkable trend of decreasing UV flux with increasing soft X-ray excess and power law emission. We suggest that this could be due to that the external edge of corona hide a fraction of accretion disk. Co-Author: Prof. Gulab C. Dewangan (IUCAA), Prof. Ranjeev Misra (IUCAA), Pramod Kumar (Nanded university)

  3. 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.

  4. ROSAT observations of the Eridanus soft X-ray enhancement

    NASA Technical Reports Server (NTRS)

    Snowden, S. L.; Burrows, D. N.; Sanders, W. T.; Aschenbach, B.; Pfeffermann, E.

    1995-01-01

    We present maps of the Eridanus soft X-ray enhancement made from the ROSAT all-sky survey data. The maps are in two energy bands: 0.25 keV (0.12-0.284 keV at 10% response, the ROSAT R1 and R2 bands), and 0.75 keV (0.47-1.20 keV at 10% response, the ROSAT R4 and R5 bands). The entire enhancement spans a total of approximately 35 deg in Galactic latitude and approximately 20 deg in Galactic longitude, centered at l approximately 22 deg, b approximately -32 deg. While the higher spatial resolution of the ROSAT data reveals a pattern of detailed anticorrelations with 100 micrometers intensity that was not evident in the HEAO 1 or earlier data, the basic morphology found in previous maps of this enhancement is confirmed. The ROSAT data also clearly show that the X-ray enhancement continues up to the Orion region in the 0.75 keV band, confirming the structure suggested by the Wisconsin sky survey maps. The ROSAT data are consistent with the interpretation of Reynolds & Ogden and Burrows et al. that this enhancement, the higher temperature component of Burrows et al., is generated for the most part by several-million-degree gas filling a huge interstellar cavity. However, we interpret the low-temperature component discussed by Burrows et al. as part of a more distant large scale (greater than or equal to approximately 30 deg) diffuse background enhancement. The part of this softer X-ray enhancement examined here appears to be produced by million degree gas in the galactic halo, and is therfore unlikely to be an isolated bubble as suggested by Burrows et al. on the basis of lower resolution HEAO 1 data.

  5. X-ray emission from cataclysmic variables with accretion disks. I - Hard X-rays. II - EUV/soft X-ray radiation

    NASA Technical Reports Server (NTRS)

    Patterson, J.; Raymond, J. C.

    1985-01-01

    Theoretical models explaining the hard-X-ray, soft-X-ray, and EUV emission of accretion-disk cataclysmic variables in terms of the disk boundary layer (DBL) are developed on the basis of a survey of the published observational data. The data are compared with model predictions in graphs for systems with high or low (greater than or less than 10-Pg/s) accretion rates. Good agreement is obtained both at low accretion rates, where an optically thin rarefied hot (Te = 10 to the 8th K) DBL radiates most of its energy as hard X-rays, and at high accretion rates, where an optically thick 100,000-K DBL radiates most of its energy in the EUV and as soft X-rays. Detailed analysis of the old nova V603 Aql suggests that previous models predicting more detections of soft-X-ray/EUV emissions from thick-DBL objects (Ferland et al., 1982) used inappropriate dwarf masses, interstellar column densities, or classical-nova space densities.

  6. Refraction effects in soft x-ray multilayer blazed gratings.

    PubMed

    Voronov, D L; Salmassi, F; Meyer-Ilse, J; Gullikson, E M; Warwick, T; Padmore, H A

    2016-05-30

    A 2500 lines/mm Multilayer Blazed Grating (MBG) optimized for the soft x-ray wavelength range was fabricated and tested. The grating coated with a W/B4C multilayer demonstrated a record diffraction efficiency in the 2nd blazed diffraction order in the energy range from 500 to 1200 eV. Detailed investigation of the diffraction properties of the grating demonstrated that the diffraction efficiency of high groove density MBGs is not limited by the normal shadowing effects that limits grazing incidence x-ray grating performance. Refraction effects inherent in asymmetrical Bragg diffraction were experimentally confirmed for MBGs. The refraction affects the blazing properties of the MBGs and results in a shift of the resonance wavelength of the gratings and broadening or narrowing of the grating bandwidth depending on diffraction geometry. The true blaze angle of the MBGs is defined by both the real structure of the multilayer stack and by asymmetrical refraction effects. Refraction effects can be used as a powerful tool in providing highly efficient suppression of high order harmonics. PMID:27410064

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

    NASA Technical Reports Server (NTRS)

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

    1981-01-01

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

  8. Coherent backscattering in the soft x-ray region

    SciTech Connect

    Matone, G.; Luccio, A.

    1986-06-01

    It is shown that coherent polarized soft x-rays can be produced by a combination of two techniques - stimulated amplification of laser light in a magnetic undulator, and Compton scattering of laser photons on an electron beam. In the combined technique, laser radiation is Compton scattered from a relativistic electron beam, whose current or charge density is periodically modulated. An electron beam and a laser beam propagate through an undulator along the same line. Inside the undulator, the laser electromagnetic waste produces a modulation of the electron energy. After some drift space, the modulation of the electron energy transforms into a modulation of the beam longitudinal charge density. The laser photons are reflected by a concave mirror against the electrons and are backscattered. In the process, their energy is greatly increased. If the electron and laser photon energy are matched properly, the modulated electron beam may act as a moving diffraction grating, and the backscattered x-rays show a high degree of coherence. The mechanism of modulation is described. The effects of electron beam energy spread, finite electron beam emittance, and undulator imperfections are discussed. The theory of scattering of a light wave by a bunched electron beam and the properties of the scattered radiation are examined. (LEW)

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

    NASA Technical Reports Server (NTRS)

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

    1979-01-01

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

  10. Observation of Organelles in Leydig Cells by Contact Soft X-Ray Microscopy with a Laser Plasma X-Ray Source

    NASA Astrophysics Data System (ADS)

    Kado, M.; Ishino, M.; Tamotsu, S.; Yasuda, K.; Kishimoto, M.; Nishikino, M.; Kinjo, Y.; Shinohara, K.

    2011-09-01

    We observed the same biological specimens for comparison of the images by contact soft x-ray microscopy with a laser plasma x-ray source with those by confocal laser microscopy. Images of wet Leydig cells were directly comparable for organelles and showed that actin filaments and mitochondria were clearly identified in the soft x-ray images.

  11. Point diffraction interferometry at soft x-ray wavelengths

    SciTech Connect

    Sommargren, G.E.; Hostetler, R.

    1993-07-01

    To achieve the image performance necessary for soft x-ray projection lithography, interferometric testing at the design wavelength is required to accurately characterize the wavefront of the imaging system. The wavefront depends not only on the surface figure of the individual optics and on their relative alignment, but also on aperture dependent phase shifts induced by the resonant multilayer coatings on the optical surfaces. This paper describes the design and lithographic fabrication of an array of point diffraction interferometers on a silicon nitride membrane that has been over-coated with a spatially graded partially transmitting film to provide fringe contrast control. Experimental results using a visible light analogue (larger pinholes and different transmission gradient) will be shown.

  12. Surface Slope Metrology on Deformable Soft X-ray Mirrors

    SciTech Connect

    Yuan, Sheng; Yashchuk, Valeriy V.; Goldberg, Kenneth A.; Celestre, Rich; Church, Matthew; McKinney, Wayne R.; Morrison, Greg; Warwick, Tony

    2010-01-31

    We report on the current state of surface slope metrology on deformable mirrors for soft x-rays at the Advanced Light Source (ALS). While we are developing techniques for in situ at-wavelength tuning, we are refining methods of ex situ visible-light optical metrology to achieve sub-100-nrad accuracy. This paper reports on laboratory studies, measurements and tuning of a deformable test-KB mirror prior to its use. The test mirror was bent to a much different optical configuration than its original design, achieving a 0.38 micro-radian residual slope error. Modeling shows that in some cases, by including the image conjugate distance as an additional free parameter in the alignment, along with the two force couples, fourth-order tangential shape errors (the so-called bird shape) can be reduced or eliminated.

  13. Surface Slope Metrology on Deformable Soft X-ray Mirrors

    SciTech Connect

    Yuan, S.; Yashchuk, V.V.; Goldberg, K.A.; Celestre, R.; Church, M.; McKinney, W.R.; Morrison, G.; Warwick, T.

    2009-09-18

    We report on the current state of surface slope metrology on deformable mirrors for soft x-rays at the Advanced Light Source (ALS). While we are developing techniques for in situ at-wavelength tuning, we are refining methods of ex situvisible-light optical metrology to achieve sub-100-nrad accuracy. This paper reports on laboratory studies, measurements and tuning of a deformable test-KB mirror prior to its use. The test mirror was bent to a much different optical configuration than its original design, achieving a 0.38 micro-radian residual slope error. Modeling shows that in some cases, by including the image conjugate distance as an additional free parameter in the alignment, along with the two force couples, fourth-order tangential shape errors (the so-called bird shape) can be reduced or eliminated.

  14. Tracing Chromospheric Evaporation in Radio and Soft X-rays

    NASA Technical Reports Server (NTRS)

    Aschwanden, Markus J.

    1997-01-01

    There are three publications in refereed journals and several presentations at scientific conferences resulted from this work, over a period of 6 months during 1995/1996. In the first paper, the discovery of the chromospheric evaporation process at radio wavelengths is described. In the second paper, the radio detection is used to quantify electron densities in the upflowing heated plasma in flare loops, which is then compared with independent other density measurements from soft X-rays, or the plasma frequency of electron beams originating in the acceleration region. In the third paper, the diagnostic results of the chromospheric evaporation process are embedded into a broader picture of a standard flare scenario. Abstracts of these three papers are attached.

  15. Imaging performance and tests of soft x-ray telescopes

    SciTech Connect

    Spiller, E.; McCorkle, R.; Wilczynski, J. . Thomas J. Watson Research Center); Golub, L.; Nystrom, G. ); Takacz, P.Z. ); Welch, C. )

    1990-08-01

    Photos obtained during 5 min. of observation time from the flight of our 10 in. normal incidence soft x-ray ({lambda} = 63.5{Angstrom}) telescope on September 11, 1989 are analyzed and the data are compared to the results expected from tests of the mirror surfaces. These tests cover a range of spatial periods from 25 cm to 1{Angstrom}. The photos demonstrate a reduction in the scattering of the multilayer mirror compared to a single surface for scattering angles above 1 arcmin, corresponding to surface irregularities with spatial periods below 10 {mu}m. Our results are used to predict the possible performance of future flights. Sounding rocket observations might be able to reach a resolution around 0.1 arcsec. Higher resolutions will require flights of longer durations and improvements in mirror testing for the largest spatial periods. 21 refs., 7 figs., 1 tab.

  16. Holography-guided ptychography with soft X-rays.

    PubMed

    Hessing, Piet; Pfau, Bastian; Guehrs, Erik; Schneider, Michael; Shemilt, Laura; Geilhufe, Jan; Eisebitt, Stefan

    2016-01-25

    Ptychography is a lensless imaging technique that aims to reconstruct an object from a set of coherent diffraction patterns originating from different and partially overlapping sample illumination areas. For a successful convergence of the iterative algorithms used, the sample scan positions have to be known with very high accuracy. Here, we present a method that allows to directly encode this information in the diffraction patterns without the need of accurate position encoders. Our approach relies on combining ptychography with another coherent imaging method, namely Fourier-transform holography. We have imaged two different objects using coherent soft-X-ray illumination and investigate the influence of experimental and numerical position refinement on the reconstruction result. We demonstrate that holographically encoded positions significantly reduce the experimental and numerical requirements. Our ptychographic reconstructions cover a large field of view with diffraction-limited resolution and high sensitivity in the reconstructed phase shift and absorption of the objects. PMID:26832562

  17. Soft x-ray undulator for the Siam Photon Source

    SciTech Connect

    Rugmai, S.; Dasri, T.; Prawanta, S.; Siriwattanapaitoon, S.; Kwankasem, A.; Sooksrimuang, V.; Chachai, W.; Suradet, N.; Juthong, N.; Tancharakorn, S.

    2007-01-19

    An undulator for production of intense soft x-rays has been designed for the Siam Photon Source. The construction of the undulator has been completed. It is now being characterized and prepared for installation. The device, named U60, is a pure permanent magnet planar undulator, consisting of 41 magnetic periods, with 60 mm period length. Utilization of the undulator radiation in the photon energy range of 30 - 900 eV is expected. The design studies of the magnetic structure, including investigation of perturbations arising from the magnetic field of the device, their effects on the SPS storage ring and compensation schemes are described. A magnetic measurement system has been constructed for magnetic characterization of the device. Partial results of magnetic measurements are presented.

  18. G-133: A soft X ray solar telescope

    NASA Astrophysics Data System (ADS)

    Williams, Memorie K.; Campbell, Branton; Roming, Peter W. A.; Spute, Mark K.; Moody, J. Ward

    1992-10-01

    The GOLDHELOX Project, NASA payload number G-133, is a robotic soft x ray solar telescope designed and built by an organization of undergraduate students. The telescope is designed to observe the sun at a wavelength of 171 to 181 A. Since we require observations free from atmospheric interference, the telescope will be launched in a NASA Get-Away-Special (GAS) canister with a Motorized Door Assembly (MDA). In this paper we primarily discuss the most important elements of the telescope itself. We also elaborate on some of the technical difficulties associated with doing good science in space on a small budget (about $100,000) and mention ways in which controlling the instrument environment has reduced the complexity of the system and thus saved us money.

  19. Soft x-ray microscope with zone plates at UVSOR

    NASA Astrophysics Data System (ADS)

    Watanabe, Norio; Shimanuki, Yoshio; Taniguchi, Mieko; Kihara, Hiroshi

    1993-01-01

    A soft x-ray microscope with zone plates was set up at UVSOR (Okazaki, Japan). A 0.41 micrometers line and space pattern was clearly distinguished using an objective zone plate with the outermost zone width of 0.41 micrometers . Modulation transfer functions were measured at wavelengths of 3.1 nm and 5.4 nm, and compared with theoretical calculations. Considering the resolution of a microchannel plate used as a detector, the agreement is fairly good. With this microscope, some biological specimens such as diatoms, spicule of trepang, crab and rabbit muscles, human blood cells, human chromosomes, and magnetotactic bacterium were observed at 3.1 nm and 5.4 nm. With an environmental chamber (wet cell) using polypropylene foils as windows, wet specimens were observed at a wavelength of 4.6 nm. Images of spicule of trepang, human blood cell, and cultured protoplast of plant cell stained by methyl mercury were observed with good contrast.

  20. Soft X-Ray Optics by Pulsed Laser Deposition

    NASA Technical Reports Server (NTRS)

    Fernandez, Felix E.

    1996-01-01

    Mo/Si and C/Co multilayers for soft x-ray optics were designed for spectral regions of interest in possible applications. Fabrication was effected by Pulsed Laser Deposition using Nd:YAG (355 nm) or excimer (248 nm) lasers in order to evaluate the suitability of this technique. Results for Mo/Si structures were not considered satisfactory due mainly to problems with particulate production and target surface modification during Si ablation. These problems may be alleviated by a two-wavelength approach, using separate lasers for each target. Results for C/Co multilayers are much more encouraging, since indication of good layering was observed for extremely thin layers. We expect to continue investigating this possibility. In order to compete with traditional PVD techniques, it is necessary to achieve film coverage uniformity over large enough areas. It was shown that this is feasible, and novel means of achieving it were devised.

  1. Soft X-Ray Observations of the Galactic Halo

    NASA Technical Reports Server (NTRS)

    Shelton, Robin; Kuntz, K. D.

    2003-01-01

    In this project, my co-I (K.D. Kuntz) and I plan to extract the soft X-ray spectrum emitted by the hot gas along a high latitude line of sight. We plan to subtract off the local component (garnered from other observations) in order to isolate the halo component. We then plan to combine this spectral information with the ultraviolet resonance line emission produced by slightly cooler gas along the line of sight and use the two observations as a constraint on models. My co-I, K.D., Kuntz has been working on the determination of the instrumental background. I have not yet drawn any of the funds for this project. I have just moved from J h s Hopkins University to the University of Georgia and anticipate finishing the project while at the University of Georgia.

  2. VUV and soft x-ray spectroscopy of actinides

    SciTech Connect

    Olson, C. G.; Joyce, J. J.; Durakiewicz, T.; Guziewicz, E.

    2004-01-01

    Optical and photoelectron spectroscopies using VUV and Soft X-ray photons are powerful tools for studies of elemental and compound actinides. Large changes in the relative atomic cross sections of the 5f, 6d and sp electrons allow decomposition of the character of the valence bands using photoemission. Resonant enhancement of photoelectrons and Auger electrons at the 5d core threshold further aids the decomposition and gives a measure of elemental specificity. Angle-resolved photoemission can be used to map the momentum dependence of the electronic states. The large changes in relative cross section with photon energy yields further details when the mapping is done at equivalent points in multiple zones. Spectra for well understood rare earth materials will be presented to establish spectral characteristics for known atomic character initial states. These signatures will be applied to the case of USb to investigate f-d hybridization near the Fermi level.

  3. G-133: A soft x ray solar telescope

    NASA Technical Reports Server (NTRS)

    Williams, Memorie K.; Campbell, Branton; Roming, Peter W. A.; Spute, Mark K.; Moody, J. Ward

    1992-01-01

    The GOLDHELOX Project, NASA payload number G-133, is a robotic soft x ray solar telescope designed and built by an organization of undergraduate students. The telescope is designed to observe the sun at a wavelength of 171 to 181 A. Since we require observations free from atmospheric interference, the telescope will be launched in a NASA Get-Away-Special (GAS) canister with a Motorized Door Assembly (MDA). In this paper we primarily discuss the most important elements of the telescope itself. We also elaborate on some of the technical difficulties associated with doing good science in space on a small budget (about $100,000) and mention ways in which controlling the instrument environment has reduced the complexity of the system and thus saved us money.

  4. Soft X-Ray Imaging Design and Analysis Methods on DIII-D

    SciTech Connect

    Shafer, Morgan W; Battaglia, D. J.; Unterberg, Ezekial A; Canik, John; Evans, T. E.; Harris, Jeffrey H; Meitner, Steven J

    2011-01-01

    A new tangential 2D Soft X-Ray Imaging System (SXRIS) is being designed to examine the edge magnetic island structure in the lower X-point region of DIII-D. A synthetic diagnostic calculation coupled to 3D emissivity estimates is used to generate phantom images. Phillips-Tikhonov regularization is used to invert the phantom images for comparison to the original emissivity model. Noise level, island size, and equilibrium accuracy are scanned to assess the feasibility of detecting edge island structures. Models of typical DIII-D discharges indicate integration times > 1 ms with accurate equilibrium reconstruction are needed for small island (< 3 cm) detection.

  5. Implementation of soft x-ray microscopy with several tens nanometers spatial resolution at NSRL

    NASA Astrophysics Data System (ADS)

    Jiang, Shiping; Chen, Liang

    2009-09-01

    A transmission soft x-ray microscope (TXM), which is similar to the full-field x-ray microscopes installed on other synchrotron radiation sources in the world, was developed at National Synchrotron Radiation Laboratory (NSRL) in Hefei. An x-ray image taken with the microscope was acquired and its spatial resolution was estimated to be better than 70nm.

  6. Discovery of Soft X-Ray Emission From Io, Europa and the Io Plasma Torus

    NASA Technical Reports Server (NTRS)

    Elsner, R. F.; Gladstone, G. R.; Waite, J. H.; Crary, F. J.; Howell, R. R.; Johnson, R. E.; Ford, P. G.; Metzger, A. E.; Hurley, K. C.; Feigelson, E. D.; Six, N. Frank (Technical Monitor)

    2001-01-01

    We report the discovery of soft (0.25 - 2 keV) x-ray emission from the moons Io and Europa, probably Ganymede, and from the Io Plasma Torus (IPT). Bombardment by energetic (greater than 10 keV) H, O, and S ions from the region of the IPT seems the likely source of the x-ray emission from the Galilean moons. According to our estimates, fluorescent x-ray emission excited by solar x-rays, even during flares from the active Sun, charge-exchange processes, previously invoked to explain Jupiter's x-ray aurora and cometary x-ray emission, and ion stripping by dust grains fall to account for the observed emission. On the other hand, bremsstrahlung emission of soft X-rays from non-thermal electrons in the few hundred to few thousand eV range may account for a substantial fraction of the observed x-ray flux from the IPT.

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

    SciTech Connect

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

    2007-06-30

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

  8. Significant acceleration of 2D-3D registration-based fusion of ultrasound and x-ray images by mesh-based DRR rendering

    NASA Astrophysics Data System (ADS)

    Kaiser, Markus; John, Matthias; Borsdorf, Anja; Mountney, Peter; Ionasec, Razvan; Nöttling, Alois; Kiefer, Philipp; Seeburger, Jörg; Neumuth, Thomas

    2013-03-01

    For transcatheter-based minimally invasive procedures in structural heart disease ultrasound and X-ray are the two enabling imaging modalities. A live fusion of both real-time modalities can potentially improve the workflow and the catheter navigation by combining the excellent instrument imaging of X-ray with the high-quality soft tissue imaging of ultrasound. A recently published approach to fuse X-ray fluoroscopy with trans-esophageal echo (TEE) registers the ultrasound probe to X-ray images by a 2D-3D registration method which inherently provides a registration of ultrasound images to X-ray images. In this paper, we significantly accelerate the 2D-3D registration method in this context. The main novelty is to generate the projection images (DRR) of the 3D object not via volume ray-casting but instead via a fast rendering of triangular meshes. This is possible, because in the setting for TEE/X-ray fusion the 3D geometry of the ultrasound probe is known in advance and their main components can be described by triangular meshes. We show that the new approach can achieve a speedup factor up to 65 and does not affect the registration accuracy when used in conjunction with the gradient correlation similarity measure. The improvement is independent of the underlying registration optimizer. Based on the results, a TEE/X-ray fusion could be performed with a higher frame rate and a shorter time lag towards real-time registration performance. The approach could potentially accelerate other applications of 2D-3D registrations, e.g. the registration of implant models with X-ray images.

  9. ON THE X-RAY OUTBURSTS OF TRANSIENT ANOMALOUS X-RAY PULSARS AND SOFT GAMMA-RAY REPEATERS

    SciTech Connect

    Cal Latin-Small-Letter-Dotless-I skan, Sirin; Ertan, Uenal

    2012-10-20

    We show that the X-ray outburst light curves of four transient anomalous X-ray pulsars (AXPs) and soft gamma-ray repeaters (SGRs), namely, XTE J1810-197, SGR 0501+4516, SGR 1627-41, and CXOU J164710.2-455216, can be produced by the fallback disk model that was also applied to the outburst light curves of persistent AXPs and SGRs in our earlier work. The model solves the diffusion equation for the relaxation of a disk that has been pushed back by a soft gamma-ray burst. The sets of main disk parameters used for these transient sources are very similar to each other and to those employed in our earlier models of persistent AXPs and SGRs. There is a characteristic difference between the X-ray outburst light curves of transient and persistent sources. This can be explained by the differences in the disk surface density profiles of the transient and persistent sources in quiescence indicated by their quiescent X-ray luminosities. Our results imply that a viscous disk instability operating at a critical temperature in the range of {approx}1300-2800 K is a common property of all fallback disks around AXPs and SGRs. The effect of the instability is more pronounced and starts earlier for the sources with lower quiescent luminosities, which leads to the observable differences in the X-ray enhancement light curves of transient and persistent sources. A single active disk model with the same basic disk parameters can account for the enhancement phases of both transient and persistent AXPs and SGRs. We also present a detailed parameter study to show the effects of disk parameters on the evolution of the X-ray luminosity of AXPs and SGRs in the X-ray enhancement phases.

  10. Chemically selective soft x-ray patterning of polymers

    SciTech Connect

    Wang, J.; Stover, H.D.; Hitchcock, A.P.; Tyliszczak, T.

    2007-06-19

    The chemically selective modification of polymer mixtures by monochromated soft X-rays has been explored using the high-brightness fine-focused 50 nm beam of a scanning transmission X-ray microscope. Four different polymer systems were examined: a polymethylmethacrylate (PMMA) polyacrylonitrile (PAN) bilayer film; a PMMA-blend-PAN microphase-separated film; a poly(MMA-co-AN) copolymer film; and a poly(ethyl cyanoacrylate) homopolymer film. A high level of chemically selective modification was achieved for the PMMA/PAN bilayer; in particular, irradiation at 288.45 eV selectively removed the carbonyl group from PMMA while irradiation at 286.80 eV selectively reduced the nitrile group of PAN, even when these irradiations were carried out at the same (x,y) position of the sample. In the last two homogeneous polymer systems, similar amounts of damage to the nitrile and carbonyl groups occurred during irradiation at either 286.80 or 288.45 eV. This is attributed to damage transfer between the C=N and C=O groups mediated by primary electrons, secondary electrons or radical/ionic processes, aided by their close spatial proximity. Although the overall thickness of the bilayer sample at 70 nm is smaller than the lateral line spreading of 100 nm, the interface between the layers appears to effectively block the transport of energy, and hence damage, between the two layers. The origins of the line spreading in homogeneous phases and possible origins of the damage blocking effect of the interface are discussed. To demonstrate chemically selective patterning, high-resolution multi-wavelength patterns were created in the PMMA/PAN bilayer system.

  11. Correlative Analysis of Hard and Soft X-ray Emissions in Solar Flares

    NASA Technical Reports Server (NTRS)

    Zarro, Dominic M.

    1997-01-01

    This report describes research performed under the Phase 3 Compton Gamma-Ray Observatory (CGRO) Guest Investigator Program. The objective of this work is to study different mechanisms of solar flare heating by comparing their predictions with simultaneous hard and soft X-ray observations. The datasets used in this work consist of hard X-ray observations from the CGRO Burst and Transient Source Experiment (BATSE) and soft X-ray observations from the Bragg Crystal Spectrometer (BCS) and Soft X-ray telescope (SXT) on the Japanese Yohkoh spacecraft.

  12. Snapshot 2D tomography via coded aperture x-ray scatter imaging

    PubMed Central

    MacCabe, Kenneth P.; Holmgren, Andrew D.; Tornai, Martin P.; Brady, David J.

    2015-01-01

    This paper describes a fan beam coded aperture x-ray scatter imaging system which acquires a tomographic image from each snapshot. This technique exploits cylindrical symmetry of the scattering cross section to avoid the scanning motion typically required by projection tomography. We use a coded aperture with a harmonic dependence to determine range, and a shift code to determine cross-range. Here we use a forward-scatter configuration to image 2D objects and use serial exposures to acquire tomographic video of motion within a plane. Our reconstruction algorithm also estimates the angular dependence of the scattered radiance, a step toward materials imaging and identification. PMID:23842254

  13. Real space soft x-ray imaging at 10 nm spatial resolution

    SciTech Connect

    Chao, Weilun; Fischer, Peter; Tyliszczak, T.; Rekawa, Senajith; Anderson, Erik; Naulleau, Patrick

    2011-04-24

    Using Fresnel zone plates made with our robust nanofabrication processes, we have successfully achieved 10 nm spatial resolution with soft x-ray microscopy. The result, obtained with both a conventional full-field and scanning soft x-ray microscope, marks a significant step forward in extending the microscopy to truly nanoscale studies.

  14. X-ray/UV variability and the origin of soft X-ray excess emission from II Zw 177

    NASA Astrophysics Data System (ADS)

    Pal, Main; Dewangan, Gulab C.; Misra, Ranjeev; Pawar, Pramod K.

    2016-03-01

    We study X-ray and UV emission from the narrow-line Seyfert 1 galaxy II Zw 177 using a 137 ks long and another 13 ks short XMM-Newton observation performed in 2012 and 2001, respectively. Both observations show soft X-ray excess emission contributing 76.9 ± 4.9 per cent in 2012 and 58.8 ± 10.2 per cent in 2001 in the 0.3-2 keV band. We find that both blurred reflection from an ionized disc and Comptonized disc emission describe the observed soft excess well. Time-resolved spectroscopy on scales of ˜20 ks reveals strong correlation between the soft excess and the power-law components. The fractional variability amplitude Fvar derived from EPIC-pn light curves at different energy bands is nearly constant (Fvar ˜ 20 per cent). This is in contrast to other active galactic nuclei where the lack of short term variation in soft X-ray excess emission has been attributed to intense light bending in the framework of the `lamppost' model. Thus, the variations in power-law emission are most likely intrinsic to corona rather than just due to the changes of height of compact corona. The variable UV emission (Fvar ˜ 1 per cent) is uncorrelated to any of the X-ray components on short time-scales suggesting that the UV emission is not dominated by the reprocessed emission. The gradual observed decline in the UV emission in 2012 may be related to the secular decline due to the changes in the accretion rate. In this case, the short term X-ray variability is not due to the changes in the seed photons but intrinsic to the hot corona.

  15. Recover soft x-ray spectrum using virtual flat response channels with filtered x-ray diode array.

    PubMed

    Tianming, Song; Jiamin, Yang; Rongqing, Yi

    2012-11-01

    A method for the recovery of soft x-ray spectra in indirect-drive inertial confinement fusion experiments is presented. Virtual detection channels with bandpass responses are obtained using linear combinations of the channel response functions of a filtered x-ray diode array and a weighted correction is introduced to improve the recovery. These virtual channels can be used to calculate radiation fluxes in some specific photon energy bands and hence to recover the spectrum of the whole photon energy range from 80 eV to 4.5 keV. Examples are listed which demonstrate the capability of this method to unfold various spectra such as Planck spectra with different radiation temperatures and to obtain x-ray flux of certain narrow energy interval. PMID:23206046

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

    SciTech Connect

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

    2015-11-01

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

  17. Retrieving spin textures on curved magnetic thin films with full-field soft X-ray microscopies

    PubMed Central

    Streubel, Robert; Kronast, Florian; Fischer, Peter; Parkinson, Dula; Schmidt, Oliver G.; Makarov, Denys

    2015-01-01

    X-ray tomography is a well-established technique to characterize 3D structures in material sciences and biology; its magnetic analogue—magnetic X-ray tomography—is yet to be developed. Here we demonstrate the visualization and reconstruction of magnetic domain structures in a 3D curved magnetic thin films with tubular shape by means of full-field soft X-ray microscopies. The 3D arrangement of the magnetization is retrieved from a set of 2D projections by analysing the evolution of the magnetic contrast with varying projection angle. Using reconstruction algorithms to analyse the angular evolution of 2D projections provides quantitative information about domain patterns and magnetic coupling phenomena between windings of azimuthally and radially magnetized tubular objects. The present approach represents a first milestone towards visualizing magnetization textures of 3D curved thin films with virtually arbitrary shape. PMID:26139445

  18. Retrieving spin textures on curved magnetic thin films with full-field soft X-ray microscopies

    DOE PAGESBeta

    Streubel, Robert; Kronast, Florian; Fischer, Peter; Parkinson, Dula; Schmidt, Oliver G.; Makarov, Denys

    2015-07-03

    X-ray tomography is a well-established technique to characterize 3D structures in material sciences and biology; its magnetic analogue—magnetic X-ray tomography—is yet to be developed. We demonstrate the visualization and reconstruction of magnetic domain structures in a 3D curved magnetic thin films with tubular shape by means of full-field soft X-ray microscopies. In the 3D arrangement of the magnetization is retrieved from a set of 2D projections by analysing the evolution of the magnetic contrast with varying projection angle. By using reconstruction algorithms to analyse the angular evolution of 2D projections provides quantitative information about domain patterns and magnetic coupling phenomenamore » between windings of azimuthally and radially magnetized tubular objects. In conclusion, the present approach represents a first milestone towards visualizing magnetization textures of 3D curved thin films with virtually arbitrary shape.« less

  19. Retrieving spin textures on curved magnetic thin films with full-field soft X-ray microscopies

    SciTech Connect

    Streubel, Robert; Kronast, Florian; Fischer, Peter; Parkinson, Dula; Schmidt, Oliver G.; Makarov, Denys

    2015-07-03

    X-ray tomography is a well-established technique to characterize 3D structures in material sciences and biology; its magnetic analogue—magnetic X-ray tomography—is yet to be developed. We demonstrate the visualization and reconstruction of magnetic domain structures in a 3D curved magnetic thin films with tubular shape by means of full-field soft X-ray microscopies. In the 3D arrangement of the magnetization is retrieved from a set of 2D projections by analysing the evolution of the magnetic contrast with varying projection angle. By using reconstruction algorithms to analyse the angular evolution of 2D projections provides quantitative information about domain patterns and magnetic coupling phenomena between windings of azimuthally and radially magnetized tubular objects. In conclusion, the present approach represents a first milestone towards visualizing magnetization textures of 3D curved thin films with virtually arbitrary shape.

  20. Retrieving spin textures on curved magnetic thin films with full-field soft X-ray microscopies.

    PubMed

    Streubel, Robert; Kronast, Florian; Fischer, Peter; Parkinson, Dula; Schmidt, Oliver G; Makarov, Denys

    2015-01-01

    X-ray tomography is a well-established technique to characterize 3D structures in material sciences and biology; its magnetic analogue--magnetic X-ray tomography--is yet to be developed. Here we demonstrate the visualization and reconstruction of magnetic domain structures in a 3D curved magnetic thin films with tubular shape by means of full-field soft X-ray microscopies. The 3D arrangement of the magnetization is retrieved from a set of 2D projections by analysing the evolution of the magnetic contrast with varying projection angle. Using reconstruction algorithms to analyse the angular evolution of 2D projections provides quantitative information about domain patterns and magnetic coupling phenomena between windings of azimuthally and radially magnetized tubular objects. The present approach represents a first milestone towards visualizing magnetization textures of 3D curved thin films with virtually arbitrary shape. PMID:26139445

  1. Retrieving spin textures on curved magnetic thin films with full-field soft X-ray microscopies

    NASA Astrophysics Data System (ADS)

    Streubel, Robert; Kronast, Florian; Fischer, Peter; Parkinson, Dula; Schmidt, Oliver G.; Makarov, Denys

    2015-07-01

    X-ray tomography is a well-established technique to characterize 3D structures in material sciences and biology; its magnetic analogue--magnetic X-ray tomography--is yet to be developed. Here we demonstrate the visualization and reconstruction of magnetic domain structures in a 3D curved magnetic thin films with tubular shape by means of full-field soft X-ray microscopies. The 3D arrangement of the magnetization is retrieved from a set of 2D projections by analysing the evolution of the magnetic contrast with varying projection angle. Using reconstruction algorithms to analyse the angular evolution of 2D projections provides quantitative information about domain patterns and magnetic coupling phenomena between windings of azimuthally and radially magnetized tubular objects. The present approach represents a first milestone towards visualizing magnetization textures of 3D curved thin films with virtually arbitrary shape.

  2. Probing transverse coherence of x-ray beam with 2-D phase grating interferometer

    PubMed Central

    Marathe, Shashidhara; Shi, Xianbo; Wojcik, Michael J.; Kujala, Naresh G.; Divan, Ralu; Mancini, Derrick C.; Macrander, Albert T.; Assoufid, Lahsen

    2014-01-01

    Transverse coherence of the x-ray beam from a bending magnet source was studied along multiple directions using a 2-D π/2 phase grating by measuring interferogram visibilities at different distances behind the grating. These measurements suggest that the preferred measuring orientation of a 2-D checkerboard grating is along the diagonal directions of the square blocks, where the interferograms have higher visibility and are not sensitive to the deviation of the duty cycle of the grating period. These observations are verified by thorough wavefront propagation simulations. The accuracy of the measured coherence values was also validated by the simulation and analytical results obtained from the source parameters. In addition, capability of the technique in probing spatially resolved local transverse coherence is demonstrated. PMID:24977503

  3. Probing transverse coherence of x-ray beam with 2-D phase grating interferometer.

    PubMed

    Marathe, Shashidhara; Shi, Xianbo; Wojcik, Michael J; Kujala, Naresh G; Divan, Ralu; Mancini, Derrick C; Macrander, Albert T; Assoufid, Lahsen

    2014-06-16

    Transverse coherence of the x-ray beam from a bending magnet source was studied along multiple directions using a 2-D π/2 phase grating by measuring interferogram visibilities at different distances behind the grating. These measurements suggest that the preferred measuring orientation of a 2-D checkerboard grating is along the diagonal directions of the square blocks, where the interferograms have higher visibility and are not sensitive to the deviation of the duty cycle of the grating period. These observations are verified by thorough wavefront propagation simulations. The accuracy of the measured coherence values was also validated by the simulation and analytical results obtained from the source parameters. In addition, capability of the technique in probing spatially resolved local transverse coherence is demonstrated. PMID:24977503

  4. White dwarfs as the maximal soft x-ray scatterers

    SciTech Connect

    Akbari-Moghanjoughi, M.

    2013-09-15

    In this paper, we explore the effect of density on the structure formation and the electromagnetic wave (EMw) elastic scattering on quantum plasmas, using the generalized quantum hydrodynamic model valid for a wide range of the plasma density and relativistic degeneracy. It is found that the electron quantum diffraction effect caused by the Bohm potential has a fundamental effect on the ion correlations in a degenerate electron fluid and crystallization in quantum plasmas in the solid-density regime and beyond. The ion correlations and structure formation are shown to be fundamentally affected by the plasma density and the relativistic degeneracy parameters. Moreover, distinct behavior is shown to exist between the non-relativistic and relativistic matter density regimes, regarding the normalized EMw elastic scattering cross-sections. It is theoretically discovered that the maximal Thomson scattering coincides with the average density of a typical white dwarf corresponding to the soft X-ray wavelength regime. Current research can be very useful in plasma optical diagnostic methods for a wide range of electron number-density from warm dense matter and inertial confinement fusion to the astrophysical compact objects.

  5. Toward a soft x-ray Fourier-transform spectrometer

    SciTech Connect

    Howells, M.R.; Frank, K.; Hussain, Z.; Moler, E.J.; Reich, T. |; Moeller, D.; Shirley, D.A.

    1993-10-29

    The use of Fourier transform spectroscopy (FTS) in the soft x-ray region is advocated as a possible route to spectral resolution superior to that attainable with a grating system. A technical plan is described for applying FTS to the study of the absorption spectrum of helium in the region of double ionization around 60--80 eV. The proposed scheme includes a Mach-Zehnder interferometer deformed into a rhombus shape to provide grazing incidence reflections. The path difference between the interfering beams is to be tuned by translation of a table carrying four mirrors over a range {+-}1 cm which, in the absence of errors generating relative tilts of the wave fronts, would provide a resolving power equal to the number of waves of path difference: half a million at 65 eV, for example. The signal-to-noise ratio of the spectrum is analyzed and for operation on an Advanced Light Source bending magnet beam line should be about 330.

  6. Soft X Ray Telescope (SXT) focus error analysis

    NASA Technical Reports Server (NTRS)

    Ahmad, Anees

    1991-01-01

    The analysis performed on the soft x-ray telescope (SXT) to determine the correct thickness of the spacer to position the CCD camera at the best focus of the telescope and to determine the maximum uncertainty in this focus position due to a number of metrology and experimental errors, and thermal, and humidity effects is presented. This type of analysis has been performed by the SXT prime contractor, Lockheed Palo Alto Research Lab (LPARL). The SXT project office at MSFC formed an independent team of experts to review the LPARL work, and verify the analysis performed by them. Based on the recommendation of this team, the project office will make a decision if an end to end focus test is required for the SXT prior to launch. The metrology and experimental data, and the spreadsheets provided by LPARL are used at the basis of the analysis presented. The data entries in these spreadsheets have been verified as far as feasible, and the format of the spreadsheets has been improved to make these easier to understand. The results obtained from this analysis are very close to the results obtained by LPARL. However, due to the lack of organized documentation the analysis uncovered a few areas of possibly erroneous metrology data, which may affect the results obtained by this analytical approach.

  7. Plasma Emission Profile Recreation using Soft X-Ray Tomography

    NASA Astrophysics Data System (ADS)

    Page, J. W.; Mauel, M. E.; Levesque, J. P.

    2015-11-01

    With sufficient views from multiple diode arrays, soft X-ray tomography is an invaluable plasma diagnostic because it is a non-perturbing method to reconstruct the emission within the interior of the plasma. In preparation for the installation of new SXR arrays in HBT-EP, we compute high-resolution tomographic reconstructions of discharges having kink-like structures that rotate nearly rigidly. By assuming a uniform angular mapping from the kink mode rotation, Δϕ ~ ωΔ t, a temporal sequence from a single 16-diode fan array represents as many as 16 x 100 independent views. We follow the procedure described by Wang and Granetz and use Bessel basis functions to take the inverse Radon transform. This transform is fit to our data using a least-squares method to estimate the internal SXR emissivity as a sum of polar functions. By varying different parameters of the transformation, we optimize the quality of our recreation of the emission profile and quantify how the reconstruction changes with the azimuthal order of the transform. Supported by U.S. DOE Grant DE-FG02-86ER53222.

  8. Multi-energy Soft X-ray diagnostic for NSTX

    NASA Astrophysics Data System (ADS)

    Tritz, Kevin; Stutman, Dan; Finkenthal, Michael; Kumar, Deepak; Clayton, Daniel

    2010-11-01

    A high resolution, ``multi-energy'' soft X-ray (ME-SXR) diagnostic is being developed for the NSTX edge plasma. The system will measure with spatial resolution of <=1cm and with ˜10 kHz bandwidth the XUV and SXR emission from the outer NSTX regions, including the pedestal, and will serve for studies of edge particle and electron transport, of ELM dynamics, and other edge phenomena. The system comprises five tangential AXUV diode arrays, viewing the plasma between 0.5

  9. The stellar contribution to the galactic soft X-ray background

    NASA Technical Reports Server (NTRS)

    Rosner, R.; Avni, Y.; Bookbinder, J.; Giacconi, R.; Golub, L.; Harnden, F. R., Jr.; Maxson, C. W.; Topka, K.; Vaiana, G. S.

    1981-01-01

    Log N-log S relations for stars are constructed based on median X-ray luminosities for dF, dG, and dK stars previously reported for the Einstein Observatory/Center for Astrophysics stellar survey and on a detailed X-ray luminosity function derived here for dM stars, and the stellar contribution to the diffuse soft X-ray background is investigated. The principal results are that stars provide approximately 20% of the soft X-ray background in the 0.28-1.0 keV passband and therefore contribute significantly to the soft X-ray background in this energy range (with dM stars constituting the dominant contributing class), and that the stellar contribution to the diffuse X-ray background in the 0.15-0.28 keV passband is less than approximately 3%.

  10. TOPICAL REVIEW: Human soft tissue analysis using x-ray or gamma-ray techniques

    NASA Astrophysics Data System (ADS)

    Theodorakou, C.; Farquharson, M. J.

    2008-06-01

    This topical review is intended to describe the x-ray techniques used for human soft tissue analysis. X-ray techniques have been applied to human soft tissue characterization and interesting results have been presented over the last few decades. The motivation behind such studies is to provide improved patient outcome by using the data obtained to better understand a disease process and improve diagnosis. An overview of theoretical background as well as a complete set of references is presented. For each study, a brief summary of the methodology and results is given. The x-ray techniques include x-ray diffraction, x-ray fluorescence, Compton scattering, Compton to coherent scattering ratio and attenuation measurements. The soft tissues that have been classified using x-rays or gamma rays include brain, breast, colon, fat, kidney, liver, lung, muscle, prostate, skin, thyroid and uterus.

  11. Observation of soft X-rays from extended sources. [such as Perseus star cluster

    NASA Technical Reports Server (NTRS)

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

    1974-01-01

    Efforts were directed toward surveying several supernova remnants for the emission of soft X-rays. Rather than attempt to detect such faint X-ray emission, the program was redirected to observe the spectrum and angular structure of the extended X-ray source in the Perseus cluster of galaxies and the super-nova remnant Puppis A. An attempt was made to detect X-ray line emission from Puppis A with a Bragg crystal spectrometer. Observations provide evidence for the presence of X-ray line emission in the spectrum of Puppis A near .65 keV.

  12. Biological imaging by soft X-ray diffraction microscopy

    NASA Astrophysics Data System (ADS)

    Shapiro, David

    We have developed a microscope for soft x-ray diffraction imaging of dry or frozen hydrated biological specimens. This lensless imaging system does not suffer from the resolution or specimen thickness limitations that other short wavelength microscopes experience. The microscope, currently situated at beamline 9.0.1 of the Advanced Light Source, can collect diffraction data to 12 nm resolution with 750 eV photons and 17 nm resolution with 520 eV photons. The specimen can be rotated with a precision goniometer through an angle of 160 degrees allowing for the collection of nearly complete three-dimensional diffraction data. The microscope is fully computer controlled through a graphical user interface and a scripting language automates the collection of both two-dimensional and three-dimensional data. Diffraction data from a freeze-dried dwarf yeast cell, Saccharomyces cerevisiae carrying the CLN3-1 mutation, was collected to 12 run resolution from 8 specimen orientations spanning a total rotation of 8 degrees. The diffraction data was phased using the difference map algorithm and the reconstructions provide real space images of the cell to 30 nm resolution from each of the orientations. The agreement of the different reconstructions provides confidence in the recovered, and previously unknown, structure and indicates the three dimensionality of the cell. This work represents the first imaging of the natural complex refractive contrast from a whole unstained cell by the diffraction microscopy method and has achieved a resolution superior to lens based x-ray tomographic reconstructions of similar specimens. Studies of the effects of exposure to large radiation doses were also carried out. It was determined that the freeze-dried cell suffers from an initial collapse, which is followed by a uniform, but slow, shrinkage. This structural damage to the cell is not accompanied by a diminished ability to see small features in the specimen. Preliminary measurements on frozen

  13. Probing nucleobase photo protection with soft x-rays

    NASA Astrophysics Data System (ADS)

    Gühr, Markus

    2013-05-01

    We [1] present a new method for ultrafast spectroscopy of molecular photoexcited dynamics. The technique uses a pair of femtosecond pulses: a photoexcitation pulse initiating excited state dynamics followed by a soft x-ray (SXR) probe pulse that core ionizes certain atoms inside the molecule. We observe the Auger decay of the core hole as a function of delay between the photoexcitation and SXR pulses. The core hole decay is particularly sensitive to the local valence electrons near the core and shows new types of propensity rules, compared to dipole selection rules in SXR absorption or emission spectroscopy. We apply the delayed ultrafast x-ray Auger probing (DUXAP) method to the specific problem of nucleobase photoprotection to demonstrate its potential. The ultraviolet photoexcited ππ * states of nucleobases are prone to chemical reactions with neighboring bases. To avoid this, the single molecules funnel the ππ * population to lower lying electronic states on an ultrafast timescale under violation of the Born-Oppenheimer approximation. The new type of propensity rule, which is confirmed by Auger decay simulations, allows us to have increased sensitivity on the direct relaxation from the ππ * state to the vibrationally hot electronic ground state. For the nucleobase thymine, we measure a decay of the ππ * state and a subsequent filling of the vibrationally hot ground state in 300 fs. This work was supported by the AMOS program within the Chemical Sciences, Geosciences, and Biosciences Division of the Office of Basic Energy Sciences, Office of Science, U.S. Department of Energy.Portions of this research were carried out at the Linac Coherent Light Source (LCLS) at the SLAC National Accelerator Laboratory. LCLS is an Office of Science User Facility operated for the U.S. Department of Energy Office of Science by Stanford University. Other portions of this research were carried out at the Advanced Light Source, which is supported by the Director, Office of

  14. Implications of stimulated resonant X-ray scattering for spectroscopy, imaging, and diffraction in the regime from soft to hard X-rays

    NASA Astrophysics Data System (ADS)

    Schreck, Simon; Beye, Martin; Föhlisch, Alexander

    2015-12-01

    The ultrahigh peak brilliance available at X-ray free-electron lasers opens the possibility to transfer nonlinear spectroscopic techniques from the optical and infrared into the X-ray regime. Here, we present a conceptual treatment of nonlinear X-ray processes with an emphasis on stimulated resonant X-ray scattering as well as a quantitative estimate for the scaling of stimulated X-ray scattering cross sections. These considerations provide the order of magnitude for the required X-ray intensities to experimentally observe stimulated resonant X-ray scattering for photon energies ranging from the extreme ultraviolet to the soft and hard X-ray regimes. At the same time, the regime where stimulated processes can safely be ignored is identified. With this basis, we discuss prospects and implications for spectroscopy, scattering, and imaging experiments at X-ray free-electron lasers.

  15. Picosecond soft-x-ray pulses from a high-intensity laser-plasma source.

    PubMed

    Pelletier, J F; Chaker, M; Kieffer, J C

    1996-07-15

    We report time-resolved spectroscopic analysis of laser-produced plasma x-ray sources. Plasmas produced by a 400-fs 1-TW tabletop laser are characterized with a transmission grating spectrometer coupled to a soft-x-ray streak camera. Soft-x-ray radiation in the 1-6-nm range with durations of 2-7 ps is observed for copper and tantalum plasmas. The effect of incident laser energy on the x-ray pulse duration is also investigated. PMID:19876245

  16. Soft-x-ray hollow fiber optics with inner metal coating.

    PubMed

    Matsuura, Yuji; Oyama, Tadaaki; Miyagi, Mitsunobu

    2005-10-10

    A glass capillary with an inner metal coating is proposed to be used as soft-x-ray fiber optics in medical applications. Based on the results of theoretical calculations, nickel was chosen as the coating material for x rays radiated from a conventional x-ray tube. A nickel-coated capillary was fabricated by electroless deposition, and focusing and collimating effects were observed from measurements of the transmission efficiency of soft x rays. The transmission of a nickel-coated capillary with an inner diameter of 0.53 mm and a length of 300 mm was 10%, which is approximately double that of an uncoated glass capillary. PMID:16237934

  17. Ground-based x-ray calibration of the Astro-H soft x-ray telescopes

    NASA Astrophysics Data System (ADS)

    Iizuka, Ryo; Hayashi, Takayuki; Maeda, Yoshitomo; Ishida, Manabu; Tomikawa, Kazuki; Sato, Toshiki; Kikuchi, Naomichi; Okajima, Takashi; Soong, Yang; Serlemitsos, Peter J.; Mori, Hideyuki; Izumiya, Takanori; Minami, Sari

    2014-07-01

    The X-ray astronomy satellite Astro-H, planned to be launched in 2015, will have several instruments for covering a wide energy band from a few hundreds eV to 600 keV. There are four X-ray telescopes, and two of them are soft X-ray telescopes (SXTs) covering up to about 15 keV. One is for an X-ray micro-calorimeter detector (SXS) and the other is for an X-ray CCD detector (SXI). The design of the SXTs is a conical approximation of the Wolter Type-I optics, which is also adopted for the telescopes on the previous mission Suzaku launched in 2005. It consists 203 thin-foil reflectors coated with gold monolayer (2000 Å) on the aluminum substrate (101.6 mm length) with the thickness of 0.15, 0.23 and 0.31 mm. These are nested confocally within the radius of 58 to 225 mm. The focal length of SXTs is 5.6 m. The weight is as light as ~ 43 kg per telescope. We present the current status of the calibration activity of two SXTs (SXT-1 and SXT-2). The developments of two SXTs were completed by NASA's Goddard Space Flight Center (GSFC). First X-ray measurements with a diverging beam at the GSFC 100m beamline found an angular resolution at 8.0 keV to be 1.1 and 1.0 arcmin (HPD) for SXT-1 and SXT-2, respectively. The full characterization of the X-ray performance has been now continuously calibrated with the 30m X-ray beamline facility at the Institute of Space and Astronautical Science (ISAS) of Japan Aerospace eXploration Agency (JAXA) in Japan. We adopted a raster scan method with a narrow X-ray pencil beam with the divergence of ~ 15". X-ray characterization of the two SXTs has been measured from May and December 2013, respectively. In the case of SXT-1, the on-axis effective area was approximately 580, 445, 370, 270, 185 and 90 cm2 at energies of 1.5, 4.5, 8.0, 9.4, 11.1 and 12.9 keV respectively. The effective area of SXT-2 is 2% larger than that of SXT-1 irrespective to X-ray energy. The on-axis angular resolution of SXT-1 was evaluated as 1.3 - 1.5 arcmin (HPD) in the 1

  18. Soft X-Ray Observations of a Complete Sample of X-Ray--selected BL Lacertae Objects

    NASA Astrophysics Data System (ADS)

    Perlman, Eric S.; Stocke, John T.; Wang, Q. Daniel; Morris, Simon L.

    1996-01-01

    We present the results of ROSAT PSPC observations of the X-ray selected BL Lacertae objects (XBLs) in the complete Einstein Extended Medium Sensitivity Survey (EM MS) sample. None of the objects is resolved in their respective PSPC images, but all are easily detected. All BL Lac objects in this sample are well-fitted by single power laws. Their X-ray spectra exhibit a variety of spectral slopes, with best-fit energy power-law spectral indices between α = 0.5-2.3. The PSPC spectra of this sample are slightly steeper than those typical of flat ratio-spectrum quasars. Because almost all of the individual PSPC spectral indices are equal to or slightly steeper than the overall optical to X-ray spectral indices for these same objects, we infer that BL Lac soft X-ray continua are dominated by steep-spectrum synchrotron radiation from a broad X-ray jet, rather than flat-spectrum inverse Compton radiation linked to the narrower radio/millimeter jet. The softness of the X-ray spectra of these XBLs revives the possibility proposed by Guilbert, Fabian, & McCray (1983) that BL Lac objects are lineless because the circumnuclear gas cannot be heated sufficiently to permit two stable gas phases, the cooler of which would comprise the broad emission-line clouds. Because unified schemes predict that hard self-Compton radiation is beamed only into a small solid angle in BL Lac objects, the steep-spectrum synchrotron tail controls the temperature of the circumnuclear gas at r ≤ 1018 cm and prevents broad-line cloud formation. We use these new ROSAT data to recalculate the X-ray luminosity function and cosmological evolution of the complete EMSS sample by determining accurate K-corrections for the sample and estimating the effects of variability and the possibility of incompleteness in the sample. Our analysis confirms that XBLs are evolving "negatively," opposite in sense to quasars, with Ve/Va = 0.331±0.060. The statistically significant difference between the values for

  19. Small scale H I structure and the soft X-ray background

    NASA Technical Reports Server (NTRS)

    Jahoda, K.; Mccammon, D.; Lockman, F. J.

    1986-01-01

    The observed anticorrelation between diffuse soft X-ray flux and H I column density has been explained as absorption of soft X-rays produced in a hot galactic halo, assuming that the neutral interstellar material is sufficiently clumped to reduce the soft X-ray absorption cross section by a factor of two to three. A 21 cm emission line study of H I column density variations at intermediate and high galactic latitudes to 10' spatial resolution has been done. The results confirm conclusions from preliminary work at coarser resolution, and in combination with other data appear to rule out the hypothesis that clumping of neutral interstellar matter on any angular scale significantly reduces X-ray absorption cross sections in the 0.13 - 0.28 keV energy range. It is concluded therefore that the observed anticorrelation is not primarily a consequence of absorption of soft X-rays produced in a hot galactic halo.

  20. Soft X-ray spectral observations of quasars and high X-ray luminosity Seyfert galaxies

    NASA Technical Reports Server (NTRS)

    Petre, R.; Mushotzky, R. F.; Krolik, J. H.; Holt, S. S.

    1983-01-01

    Results of the analysis of 28 Einstein SSS observations of 15 high X-ray luminosity (L(x) 10 to the 435 power erg/s) quasars and Seyfert type 1 nuclei are presented. The 0.75-4.5 keV spectra are in general well fit by a simple model consisting of a power law plus absorption by cold gas. The averager spectral index alpha is 0.66 + or - .36, consistent with alpha for the spectrum of these objects above 2 keV. In all but one case, no evidence was found for intrinsic absorption, with an upper limit of 2 x 10 to the 21st power/sq cm. Neither was evidence found for partial covering of the active nucleus by dense, cold matter (N(H) 10 to the 22nd power/sq cm; the average upper limit on the partial covering fraction is 0.5. There is no obvious correlation between spectral index and 0175-4.5 keV X-ray luminosity (which ranges from 3 x 10 to the 43rd to 47th powers erg/s or with other source properties. The lack of intrinsic X-ray absorption allows us to place constraints on the density and temperature of the broad-line emission region, and narrow line emission region, and the intergalactic medium.

  1. The Soft X-Ray Spectrometer (SXS) for the ISAS/JAXA New Exploration X-Ray Telescope

    NASA Astrophysics Data System (ADS)

    Kelley, Richard L.; Kilbourne, C. A.; McCammon, D.; Mushotzky, R. F.; Okajima, T.; Petre, R.; Porter, F. S.; Serlemitsos, P. J.; Smith, R. K.; Soong, Y.; Szymkowiak, A. E.; Mitsuda, K.; Ohashi, T.; Ishisaki, Y.; Ezoe, Y.; Yamasaki, N. Y.; Shinozaki, K.; Fujimoto, R.; Kawaharada, M.

    2008-03-01

    The ISAS/JAXA New Exploration X-Ray Telescope (NEXT) is now under development for launch in 2013. The observatory is designed to provide extremely high spectral resolution with large collecting area below 10 keV using an x-ray calorimeter, and a very large band pass (up to 300 keV) with extraordinary sensitivity over the range 10-80 keV using focusing x-ray optics. In this talk we will discuss plans for the Soft X-Ray Spectrometer (SXS), which uses an x-ray calorimeter array to provide the high spectral resolution. The SXS is a joint effort between ISAS and NASA and recently proposed to NASA as a Mission of Opportunity for the US participation. The SXS incorporates a 6x6 calorimeter array that has strong heritage in the Suzaku program and better than 7 eV energy resolution, with 4-5 eV expected based on recent laboratory tests. The cryogenic system will be a hybrid design with both liquid helium and mechanical coolers to provide a robust, redundant system with long life (> 3 years). The x-ray optical system (6 m focal length) uses thin-foil conical optics to provide at least 220 square cm at 6 keV. The SXS will enable a wide variety of interesting science topics to be pursued, including testing theories of structure formation using velocity measurements of clusters of galaxies and inferring the energy output from the jets and winds of active galaxies. The SXS will accurately measure metal abundances in the oldest galaxies, providing unique information on the origin of the elements, and observe matter in extreme gravitational fields, enabling time-resolved spectra from material approaching the event horizon of a black hole. Along with providing the instrument, we have proposed a well supported guest investigator program that will enable full US participation.

  2. Deconstructing the Spectrum of the Soft X-ray Background

    NASA Technical Reports Server (NTRS)

    Kuntz, K. D.; Snowden, S. L.

    2000-01-01

    The soft X-ray background in the 0.1-1.0 keV band is known to be produced by at least three sources; the Local Hot Bubble (LHB), the extragalactic power law (EPL), and a seemingly galactic component that lies outside the bulk of the absorption that is due to the ISM of the galactic disk. This last component, which we call the Trans-Absorption Emission (TAE), has been modeled by a number of groups who have derived disparate measures of its temperature. The differences have arisen from differing assumptions about the structure of the emitting gas and unrecognized methodological difficulties. In particular, spectral fitting methods do not uniquely separate the TAE from the foreground emission that is due the LHB. This "degeneracy" can be resolved using the angular variation of the absorption of the TAE. We show that the TAE cannot be characterized by a single thermal component; no single-component model can be consistent with both the spectral energy distribution of the TAE emission and the angular variation due to absorption by the galactic disk. We use the angular anticorrelation of the ROSAT All-Sky Survey with the galactic absorption to separate local from distant emission components, and to fit the spectral energy distribution of the resulting distant emission. We find that the emission is best described by a two-thermal-component model with logT(sub S) = 6.06(sup +0.14, sub -0.12) and log T(sub H) = 6.42(sup +0.14, sub -0.12). This two-thermal-component TAE fits the ROSAT spectral energy distribution significantly better than single-component models, and is consistent with both angular variation and spectral constraints.

  3. Development of short pulse soft x-ray lasers

    SciTech Connect

    Da Silva, L.B.; MacGowan, B.J.; Koch, J.A.; Mrowka, S.; Matthews, D.L.; Eder, D.; London, R.

    1993-02-01

    X-ray lasers with pulse duration shorter than 20 ps allow the possibility of imaging laser produced plasmas with {mu}m resolution. In addition, the high peak brightness of these new sources will allow us to study nonlinear optics in the xuv region. In this paper we will describe our efforts to produce collisionally pumped short pulse x-ray lasers. Initial results, which have produced {approximately} 45 ps (FWHM) x-ray lasers, using a double pulse irradiation technique are presented along with a discussion of the prospects for reducing the pulse width.

  4. Magnetic soft x-ray microscopy-imaging fast spin dynamics inmagnetic nanostructures

    SciTech Connect

    Fischer, Peter; Kim, Dong-Hyun; Mesler, Brooke L.; Chao, Weilun; Sakdinawat, Anne E.; Anderson, Erik H.

    2007-06-01

    Magnetic soft X-ray microscopy combines 15nm spatial resolution with 70ps time resolution and elemental sensitivity. Fresnel zone plates are used as X-ray optics and X-ray magnetic circular dichroism serves as magnetic contrast mechanism. Thus scientifically interesting and technologically relevant low dimensional nanomagnetic systems can be imaged at fundamental length and ultrafast time scales in a unique way. Studies include magnetization reversal in magnetic multilayers, nanopatterned systems, vortex dynamics in nanoelements and spin current induced phenomena.

  5. The Soft X-ray Spectrum of the High Mass X-Ray Binary V0332+53 in Quiescence

    NASA Astrophysics Data System (ADS)

    Elshamouty, Khaled G.; Heinke, Craig O.; Chouinard, Rhys

    2016-08-01

    The behaviour of neutron stars in high mass X-ray binaries (HMXBs) during periods of low mass transfer is of great interest. Indications of spectral softening in systems at low mass transfer rates suggest that some HMXBs are undergoing fundamental changes in their accretion regime, but the nature of the quiescent X-ray emission is not clear. We performed a 39 ks XMM-Newton observation of the transient HMXB V0332+53, finding it at a very low X-ray luminosity (Lx ˜ 4 × 1032 erg s-1). A power-law spectral fit requires an unusually soft spectral index (4.4^{+0.9}_{-0.6}), while a magnetized neutron star atmosphere model, with temperature LogTeff 6.7±0.2 K and inferred emitting radius of ˜0.2 - 0.3 km, gives a good fit. We suggest that the quiescent X-ray emission from V0332+53 is mainly from a hot spot on the surface of the neutron star. No conclusions on the presence of pulsations could be drawn due to the low count rate. Due to the high absorption column, thermal emission from the rest of the neutron star could be only weakly constrained, to LogTeff <6.14^{+0.05}_{-6.14} K, or <3 × 1033 erg s-1.

  6. High-average-power water window soft X-rays from an Ar laser plasma

    NASA Astrophysics Data System (ADS)

    Amano, Sho

    2016-07-01

    A high average power of 140 mW and high conversion efficiency of 14% were demonstrated in “water window” soft X-rays generated using a laser plasma source developed in-house, when a solid Ar target was irradiated by a commercial Nd:YAG Q-switched laser with an energy of 1 J at a repetition rate of 1 Hz. This soft X-ray power compared favorably with that produced using a synchrotron radiation source, and the developed laser plasma source can be used in various applications, such as soft X-ray microscopy, in place of synchrotron facilities.

  7. Soft x-ray spectroscopy for probing electronic and chemical states of battery materials

    NASA Astrophysics Data System (ADS)

    Wanli, Yang; Ruimin, Qiao

    2016-01-01

    The formidable challenge of developing high-performance battery system stems from the complication of battery operations, both mechanically and electronically. In the electrodes and at the electrode-electrolyte interfaces, chemical reactions take place with evolving electron states. In addition to the extensive studies of material synthesis, electrochemical, structural, and mechanical properties, soft x-ray spectroscopy provides unique opportunities for revealing the critical electron states in batteries. This review discusses some of the recent soft x-ray spectroscopic results on battery binder, transition-metal based positive electrodes, and the solid-electrolyte-interphase. By virtue of soft x-ray’s sensitivity to electron states, the electronic property, the redox during electrochemical operations, and the chemical species of the interphases could be fingerprinted by soft x-ray spectroscopy. Understanding and innovating battery technologies need a multimodal approach, and soft x-ray spectroscopy is one of the incisive tools to probe the chemical and physical evolutions in batteries.

  8. Soft X-ray transient light curves as standard candles: exponential versus linear decays

    NASA Astrophysics Data System (ADS)

    Shahbaz, T.; Charles, P. A.; King, A. R.

    1998-12-01

    A recent paper by King & Ritter proposed that the light curves of soft X-ray transients (SXTs) are dominated by the effect of irradiation of the accretion disc by the central X-rays. This prevents the onset of the cooling wave which would otherwise return the disc to the quiescent state, and so prolongs the outbursts beyond those in dwarf nova discs. KR show that the decay of the resulting X-ray light curve should be exponential or linear depending on whether or not the observed peak X-ray luminosity is sufficient to ionize the outer edge of the accretion disc. Here we examine the observed X-ray decays, and show that they are exponential or linear according to whether the peak luminosity is greater or smaller than the critical value defined by KR, strongly suggesting that the light curves are indeed irradiation dominated. We show further that the occurrence of an exponential or linear decay tends to favour the same type of decay in subsequent outbursts, so that systems usually show only one or the other type. We use the equations of KR and the observed X-ray light curve to determine the size R_h of the hot disc at the peak of the outburst. For exponential decays, R_h is found to be comparable to the circularization radius, as expected, since the disc consists entirely of material transferred from the secondary since the previous outburst. Further, R_h is directly proportional to the time at which one sees the secondary maximum (t_s), as expected, if t_s is the viscous time-scale of the irradiated disc. This implies that the orders of magnitude of the viscosity parameter alpha and disc aspect ratio H/R are such that alpha(H/R)~0.01. Observation of a secondary maximum calibrates the peak luminosity and gives the distance (D_kpc) to the source as D_kpc=4.3x10^-5t^3/2_sepsilon^1/2f^1/2F^-1/2_ptau^-1/2_d where F_p is the peak flux, tau_d is the e-folding time of the decay in days, epsilon is the radiation efficiency parameter and f is the ratio of the disc mass at the

  9. Imaging nanoscale magnetic structures with polarized soft x-ray photons

    SciTech Connect

    Fischer, P.; Im, M.-Y.

    2010-01-18

    Imaging nanoscale magnetic structures and their fast dynamics is scientifically interesting and technologically of highest relevance. The combination of circularly polarized soft X-ray photons which provide a strong X-ray magnetic circular dichroism effect at characteristic X-ray absorption edges, with a high resolution soft X-ray microscope utilizing Fresnel zone plate optics allows to study in a unique way the stochastical behavior in the magnetization reversal process of thin films and the ultrafast dynamics of magnetic vortices and domain walls in confined ferromagnetic structures. Future sources of fsec short and high intense soft X-ray photon pulses hold the promise of magnetic imaging down to fundamental magnetic length and time scales.

  10. Energetics and timing of the hard and soft X-ray emissions in white light flares

    NASA Technical Reports Server (NTRS)

    Neidig, Donald F.; Kane, Sharad R.

    1993-01-01

    By comparing the light curves in optical, hard X-ray, and soft X-ray wavelengths for eight well-observed flares, we confirm previous results indicating that the white light flare (WLF) is associated with the flare impulsive phase. The WLF emission peaks within seconds after the associated hard X-ray peak, and nearly two minutes before the 1-8 A soft X-ray peak. It is further shown that the peak power in nonthermal electrons above 50 keV is typically an order of magnitude larger, and the power in 1-8 A soft X-rays radiated over 2pi sr, at the time of the WLF peak, is an order of magnitude smaller than the peak WLF power.

  11. The Interrelation of Soft and Hard X-ray Emission During Solar Flares

    NASA Technical Reports Server (NTRS)

    Fisher, George H.

    1997-01-01

    The objective of this project is to determine the characteristics of flare energy transport processes through the study of soft X-rays, hard X-rays, and their interrelationships through analysis of Yohkoh SXT, HXT, and BCS data, and comparison with theoretical models. The personnel involved in the research include SSL Assistant Research Physicists Dr. Peng Li and Dr. James McTiernan.

  12. A CATALOG OF SOLAR X-RAY PLASMA EJECTIONS OBSERVED BY THE SOFT X-RAY TELESCOPE ON BOARD YOHKOH

    SciTech Connect

    Tomczak, M.; Chmielewska, E. E-mail: chmielewska@astro.uni.wroc.pl

    2012-03-01

    A catalog of X-ray plasma ejections (XPEs) observed by the Soft X-ray Telescope on board the Yohkoh satellite has been recently developed in the Astronomical Institute of University of Wroclaw. The catalog contains records of 368 events observed in years 1991-2001 including movies and cross-references to associated events like flares and coronal mass ejections (CMEs). One hundred sixty-three XPEs out of 368 in the catalog were not reported until now. A new classification scheme of XPEs is proposed in which morphology, kinematics, and recurrence are considered. The relation between individual subclasses of XPEs and the associated events was investigated. The results confirm that XPEs are strongly inhomogeneous, responding to different processes that occur in the solar corona. A subclass of erupting loop-like XPEs is a promising candidate to be a high-temperature precursor of CMEs.

  13. The correlation timescale of the X-ray flux during the outbursts of soft X-ray transients

    NASA Astrophysics Data System (ADS)

    Wu, Yuxiang; Yu, Wenfei; Li, Tipei

    2010-01-01

    Recent studies of black hole and neutron star low mass X-ray binaries (LMXBs) show a positive correlation between the X-ray flux at which the low/hard(LH)-to-high/soft(HS) state transition occurs and the peak flux of the following HS state. By analyzing the data from the All Sky Monitor (ASM) onboard the Rossi X-ray Timing Explorer (RXTE), we show that the HS state flux after the source reaches its HS flux peak still correlates with the transition flux during soft X-ray transient (SXT) outbursts. By studying large outbursts or flares of GX 339-4, Aql X-1 and 4U 1705-44, we have found that the correlation holds up to 250, 40, and 50 d after the LH-to-HS state transition, respectively. These time scales correspond to the viscous time scale in a standard accretion disk around a stellar mass black hole or a neutron star at a radius of ˜104-5 R g, indicating that the mass accretion rates in the accretion flow either correlate over a large range of radii at a given time or correlate over a long period of time at a given radius. If the accretion geometry is a two-flow geometry composed of a sub-Keplerian inflow or outflow and a disk flow in the LH state, the disk flow with a radius up to ˜105 R g would have contributed to the nearly instantaneous non-thermal radiation directly or indirectly, and therefore affects the time when the state transition occurs.

  14. Soft X-ray results from the Wisconsin experiment on OSO-8

    NASA Technical Reports Server (NTRS)

    Bunner, A. N.

    1978-01-01

    Design features and capabilities of a soft X-ray instrument aboard OSO 8 are discussed, and results are presented for observations of AM Her, Her X-1, and Eta Car. The observations of AM Her indicate that: (1) the spectrum is composite, with a very steep or very-low-temperature component plus a rather flat or very-high-temperature component; (2) the relative phase of soft X-ray minimum and optical V-band primary minimum has remained stable over the interval between 1975 'high-state' observations and 1976 'low-state' observations; and (3) the times of soft X-ray minima and hard X-ray maxima coincide, to within the accuracy of the observations. For Her X-1, soft X-ray turn-on is found to lag behind hard X-ray turn-on by no more than 3 hr. It is suggested that little or no absorption of the soft X-ray component occurs during the on state by cool gas within the Her X-1 system. A strong source with a spectrum peaked between 0.4 and 1.5 keV has been detected which is consistent with a point source at the position of Eta Car.

  15. A soft X-ray beamline for transmission X-ray microscopy at ALBA.

    PubMed

    Pereiro, E; Nicolás, J; Ferrer, S; Howells, M R

    2009-07-01

    The MISTRAL beamline is one of the seven phase-I beamlines at the ALBA synchrotron light source (Barcelona, Spain) that will be opened to users at the end of 2010. MISTRAL will be devoted to cryotomography in the water window and multi-keV spectral regions for biological applications. The optics design consists of a plane-grating monochromator that has been implemented using variable-line-spacing gratings to fulfil the requirements of X-ray microscopy using a reflective condenser. For instance, a fixed-focus condition independent of the included angle, constant magnification as well as coma and spherical aberration corrections are achieved with this system. The reported design is of wider use. PMID:19535865

  16. Biological imaging by soft x-ray diffraction microscopy

    DOE PAGESBeta

    Shapiro, D.; Thibault, P.; Beetz, T.; Elser, V.; Howells, M.; Jacobsen, C.; Kirz, J.; Lima, E.; Miao, H.; Neiman, A. M.; et al

    2005-10-25

    We have used the method of x-ray diffraction microscopy to image the complex-valued exit wave of an intact and unstained yeast cell. The images of the freeze-dried cell, obtained by using 750-eV x-rays from different angular orientations, portray several of the cell's major internal components to 30-nm resolution. The good agreement among the independently recovered structures demonstrates the accuracy of the imaging technique. To obtain the best possible reconstructions, we have implemented procedures for handling noisy and incomplete diffraction data, and we propose a method for determining the reconstructed resolution. This work represents a previously uncharacterized application of x-ray diffractionmore » microscopy to a specimen of this complexity and provides confidence in the feasibility of the ultimate goal of imaging biological specimens at 10-nm resolution in three dimensions.« less

  17. Biological imaging by soft x-ray diffraction microscopy

    SciTech Connect

    Shapiro, D.; Thibault, P.; Beetz, T.; Elser, V.; Howells, M.; Jacobsen, C.; Kirz, J.; Lima, E.; Miao, H.; Neiman, A. M.; Sayre, D.

    2005-10-25

    We have used the method of x-ray diffraction microscopy to image the complex-valued exit wave of an intact and unstained yeast cell. The images of the freeze-dried cell, obtained by using 750-eV x-rays from different angular orientations, portray several of the cell's major internal components to 30-nm resolution. The good agreement among the independently recovered structures demonstrates the accuracy of the imaging technique. To obtain the best possible reconstructions, we have implemented procedures for handling noisy and incomplete diffraction data, and we propose a method for determining the reconstructed resolution. This work represents a previously uncharacterized application of x-ray diffraction microscopy to a specimen of this complexity and provides confidence in the feasibility of the ultimate goal of imaging biological specimens at 10-nm resolution in three dimensions.

  18. Imaging cochlear soft tissue displacement with coherent x-rays

    NASA Astrophysics Data System (ADS)

    Rau, Christoph; Richter, Claus-Peter

    2015-10-01

    At present, imaging of cochlear mechanics at mid-cochlear turns has not been accomplished. Although challenging, this appears possible with partially coherent hard x-rays. The present study shows results from stroboscopic x-ray imaging of a test object at audio frequencies. The vibration amplitudes were quantified. In a different set of experiments, an intact and calcified gerbil temporal bone was used to determine displacements of the reticular lamina, tectorial membrane, and Reissner’s membrane with the Lucas and Kanade video flow algorithm. The experiments validated high frequency x-ray imaging and imaging in a calcified cochlea. The present work is key for future imaging of cochlear micromechanics at a high spatial resolution.

  19. A new soft x-ray pulse height analysis array in the HL-2A tokamak

    SciTech Connect

    Zhang, Y. P.; Liu Yi; Yang, J. W.; Song, X. Y.; Liao, M.; Li, X.; Yuan, G. L.; Yang, Q. W.; Duan, X. R.; Pan, C. H.

    2009-12-15

    A new soft x-ray pulse height analysis (PHA) array including nine independent subsystems, on basis of a nonconventional software multichannel analysis system and a silicon drift detector (SDD) linear array consisting of nine high performance SDD detectors, has been developed in the HL-2A tokamak. The use of SDD has greatly improved the measurement accuracy and the spatiotemporal resolutions of the soft x-ray PHA system. Since the ratio of peak to background counts obtained from the SDD PHA system is very high, p/b{>=}3000, the soft x-ray spectra measured by the SDD PHA system can approximatively be regarded as electron velocity distribution. The electron velocity distribution can be well derived in the pure ohmic and auxiliary heating discharges. The performance of the new soft x-ray PHA array and the first experimental results with some discussions are presented.

  20. Solar-terrestrial coupling: Solar soft X-rays and thermospheric nitric oxide

    NASA Astrophysics Data System (ADS)

    Barth, Charles A.; Bailey, Scott M.; Solomon, Stanley C.

    Simultaneous measurements were made of the solar soft x-ray irradiances and the thermospheric nitric oxide density in the tropics from the Student Nitric Oxide Explorer (SNOE) satellite. The analysis of these observations for 44 days of low geomagnetic activity in the spring of 1998 show that there is a correlation between the solar soft x-ray irradiances and thermospheric nitric oxide densities in the tropics. Photochemical model calculations that used the measured solar soft x-ray irradiances as input parameters adequately reproduce the magnitude of the time-varying component of the thermospheric nitric oxide in the tropics. An additional amount of nitric oxide is present in the tropics that does not vary with the time period of the solar rotation. The conclusion of this analysis is that solar soft x-rays are the primary cause of the variation in the thermospheric nitric oxide densities in the tropics during times of low geomagnetic activity.

  1. Homogeneous focusing with a transient soft X-ray laser for irradiation experiments

    NASA Astrophysics Data System (ADS)

    Kazamias, S.; Cassou, K.; Guilbaud, O.; Klisnick, A.; Ros, D.; Plé, F.; Jamelot, G.; Rus, B.; Koslová, M.; Stupka, M.; Mocek, T.; Douillet, D.; Zeitoun, Ph.; Joyeux, D.; Phalippou, D.

    2006-07-01

    We report the work done on a transient soft X-ray laser (SXRL) beam to deliver a proper extreme UV irradiation source for applications. The same optical tool was first demonstrated on a quasi stationnary state (QSS) soft X-Ray laser at the PALS Institute in Prague. The problem set by the transient soft X-Ray laser developed by the LIXAM at the LULI installation in Palaiseau is more crucial, first because the beam spatial profile is more irregular secondly because high repetition rate soft X-ray laser facilities in the future are based on this SXRL type. The spots obtained show a 20 micron average diameter and a rather homogeneous and smooth profile that make them a realistic irradiation source to interact with targets requiring relatively high fluence (near 1 J/cm 2) or intensity (near 10 11 W/cm 2) in the extreme UV domain.

  2. Diffraction grating transmission efficiencies for XUV and soft x rays.

    PubMed

    Schnopper, H W; Van Speybroeck, L P; Delvaille, J P; Epstein, A; Källne, E; Bachrach, R Z; Dijkstra, J; Lantward, L

    1977-04-01

    Efficiencies for diffraction of 45-275-eV x rays into orders by interferometrically formed, electrodeposited, gold transmission gratings have been measured on the 4 degrees beam line at the Stanford Synchrotron Radiation Project (SSRP). Anomalous dispersion affects the observed efficiency since the gold is partially transmitting to x rays. Model calculations which include anomalous dispersion are in good agreement with observations. With a suitable choice of material and thickness, a grating can be optimized for a given wavelength range by reducing the zero order transmission and enhancing the higher orders. Even orders are suppressed for a grating with equal slit and wire sizes. PMID:20168641

  3. On the source function of the soft X-ray diffuse background

    NASA Technical Reports Server (NTRS)

    Burrows, David N.; Kraft, Ralph P.

    1993-01-01

    Radiation transfer theory has been used recently to derive the source function of the soft X-ray diffuse background, resulting in the claim of evidence for 10 exp 6 K gas in the Galactic halo. We show that this analysis has several errors that invalidate its conclusions. We argue that the case for an extensive hot halo remains open, pending further work, but may be settled by the continuing series of Rosat observations of high-latitude soft X-ray shadows.

  4. 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.

  5. Introduction of soft X-ray spectromicroscopy as an advanced technique for plant biopolymers research.

    PubMed

    Karunakaran, Chithra; Christensen, Colleen R; Gaillard, Cedric; Lahlali, Rachid; Blair, Lisa M; Perumal, Vijayan; Miller, Shea S; Hitchcock, Adam P

    2015-01-01

    Soft X-ray absorption spectroscopy coupled with nano-scale microscopy has been widely used in material science, environmental science, and physical sciences. In this work, the advantages of soft X-ray absorption spectromicroscopy for plant biopolymer research were demonstrated by determining the chemical sensitivity of the technique to identify common plant biopolymers and to map the distributions of biopolymers in plant samples. The chemical sensitivity of soft X-ray spectroscopy to study biopolymers was determined by recording the spectra of common plant biopolymers using soft X-ray and Fourier Transform mid Infrared (FT-IR) spectroscopy techniques. The soft X-ray spectra of lignin, cellulose, and polygalacturonic acid have distinct spectral features. However, there were no distinct differences between cellulose and hemicellulose spectra. Mid infrared spectra of all biopolymers were unique and there were differences between the spectra of water soluble and insoluble xylans. The advantage of nano-scale spatial resolution exploited using soft X-ray spectromicroscopy for plant biopolymer research was demonstrated by mapping plant cell wall biopolymers in a lentil stem section and compared with the FT-IR spectromicroscopy data from the same sample. The soft X-ray spectromicroscopy enables mapping of biopolymers at the sub-cellular (~30 nm) resolution whereas, the limited spatial resolution in the micron scale range in the FT-IR spectromicroscopy made it difficult to identify the localized distribution of biopolymers. The advantages and limitations of soft X-ray and FT-IR spectromicroscopy techniques for biopolymer research are also discussed. PMID:25811457

  6. Running Shanghai Soft x-ray FEL with the EEHG scheme

    SciTech Connect

    Xiang, D; Stupakov, G.; /SLAC

    2008-12-18

    With the nominal beam parameters (beam energy: 0.84 GeV, slice energy spread: 168 keV, peak current: 600 A, normalized emittance: 2 mm mrad) of the Shanghai soft X-ray Free Electron Laser (SXFEL) project, we show that using the echo-enabled harmonic generation (EEHG) scheme, 9 nm coherent soft x-ray with peak power exceeding 400 MW can be generated directly from the 270 nm seeding laser.

  7. Introduction of Soft X-Ray Spectromicroscopy as an Advanced Technique for Plant Biopolymers Research

    PubMed Central

    Karunakaran, Chithra; Christensen, Colleen R.; Gaillard, Cedric; Lahlali, Rachid; Blair, Lisa M.; Perumal, Vijayan; Miller, Shea S.; Hitchcock, Adam P.

    2015-01-01

    Soft X-ray absorption spectroscopy coupled with nano-scale microscopy has been widely used in material science, environmental science, and physical sciences. In this work, the advantages of soft X-ray absorption spectromicroscopy for plant biopolymer research were demonstrated by determining the chemical sensitivity of the technique to identify common plant biopolymers and to map the distributions of biopolymers in plant samples. The chemical sensitivity of soft X-ray spectroscopy to study biopolymers was determined by recording the spectra of common plant biopolymers using soft X-ray and Fourier Transform mid Infrared (FT-IR) spectroscopy techniques. The soft X-ray spectra of lignin, cellulose, and polygalacturonic acid have distinct spectral features. However, there were no distinct differences between cellulose and hemicellulose spectra. Mid infrared spectra of all biopolymers were unique and there were differences between the spectra of water soluble and insoluble xylans. The advantage of nano-scale spatial resolution exploited using soft X-ray spectromicroscopy for plant biopolymer research was demonstrated by mapping plant cell wall biopolymers in a lentil stem section and compared with the FT-IR spectromicroscopy data from the same sample. The soft X-ray spectromicroscopy enables mapping of biopolymers at the sub-cellular (~30 nm) resolution whereas, the limited spatial resolution in the micron scale range in the FT-IR spectromicroscopy made it difficult to identify the localized distribution of biopolymers. The advantages and limitations of soft X-ray and FT-IR spectromicroscopy techniques for biopolymer research are also discussed. PMID:25811457

  8. A hard X-ray view of the soft excess in AGN

    NASA Astrophysics Data System (ADS)

    Boissay, Rozenn; Ricci, Claudio; Paltani, Stéphane

    2016-04-01

    An excess of X-ray emission below 1 keV, called soft excess, is detected in a large fraction of Seyfert 1-1.5s. The origin of this feature remains debated, as several models have been suggested to explain it, including warm Comptonization and blurred ionized reflection. In order to constrain the origin of this component, we exploit the different behaviors of these models above 10 keV. Ionized reflection covers a broad energy range, from the soft X-rays to the hard X-rays, while Comptonization drops very quickly in the soft X-rays. We present here the results of a study done on 102 Seyfert 1s (Sy 1.0, 1.2, 1.5 and NLSy1) from the Swift BAT 70-Month Hard X-ray Survey catalog. The joint spectral analysis of Swift/BAT and XMM-Newton data allows a hard X-ray view of the soft excess that is present in about 80% of the objects of our sample. We discuss how the soft-excess strength is linked to the reflection at high energy, to the photon index of the primary continuum and to the Eddington ratio. In particular, we find a positive dependence of the soft excess intensity on the Eddington ratio. We compare our results to simulations of blurred ionized-reflection models and show that they are in contradiction. By stacking both XMM-Newton and Swift/BAT spectra per soft-excess strength, we see that the shape of reflection at hard X-rays stays constant when the soft excess varies, showing an absence of link between reflection and soft excess. We conclude that the ionized-reflection model as the origin of the soft excess is disadvantaged in favor of the warm Comptonization model in our sample of Seyfert 1s.

  9. A table-top femtosecond time-resolved soft x-ray transient absorption spectrometer

    SciTech Connect

    Leone, Stephen; Loh, Zhi-Heng; Khalil, Munira; Correa, Raoul E.; Leone, Stephen R.

    2008-05-21

    A laser-based, table-top instrument is constructed to perform femtosecond soft x-ray transient absorption spectroscopy. Ultrashort soft x-ray pulses produced via high-order harmonic generation of the amplified output of a femtosecond Ti:sapphire laser system are used to probe atomic core-level transient absorptions in atoms and molecules. The results provide chemically specific, time-resolved dynamics with sub-50-fs time resolution. In this setup, high-order harmonics generated in a Ne-filled capillary waveguide are refocused by a gold-coated toroidal mirror into the sample gas cell, where the soft x-ray light intersects with an optical pump pulse. The transmitted high-order harmonics are spectrally dispersed with a home-built soft x-ray spectrometer, which consists of a gold-coated toroidal mirror, a uniform-line spaced plane grating, and a soft x-ray CCD camera. The optical layout of the instrument, design of the soft x-ray spectrometer, and spatial and temporal characterization of the high-order harmonics are described. Examples of static and time-resolved photoabsorption spectra collected on this apparatus are presented.

  10. Ground Laboratory Soft X-Ray Durability Evaluation of Aluminized Teflon FEP Thermal Control Insulation. Revised

    NASA Technical Reports Server (NTRS)

    Banks, Bruce A.; deGroh, Kim K.; Stueber, Thomas J.; Sechkar, Edward A.; Hall, Rachelle L.

    1998-01-01

    Metallized Teflon fluorinated ethylene propylene (FEP) thermal control insulation is mechanically degraded if exposed to a sufficient fluence of soft x-ray radiation. Soft x-ray photons (4-8 A in wavelength or 1.55 - 3.2 keV) emitted during solar flares have been proposed as a cause of mechanical properties degradation of aluminized Teflon FEP thermal control insulation on the Hubble Space Telescope (HST). Such degradation can be characterized by a reduction in elongation-to-failure of the Teflon FEP. Ground laboratory soft x-ray exposure tests of aluminized Teflon FEP were conducted to assess the degree of elongation degradation which would occur as a result of exposure to soft x-rays in the range of 3-10 keV. Tests results indicate that soft x-ray exposure in the 3-10 keV range, at mission fluence levels, does not alone cause the observed reduction in elongation of flight retrieved samples. The soft x-ray exposure facility design, mechanical properties degradation results and implications will be presented.

  11. Ground Laboratory Soft X-Ray Durability Evaluation of Aluminized Teflon FEP Thermal Control Insulation

    NASA Technical Reports Server (NTRS)

    Banks, Bruce A.; deGroh, Kim K.; Stueber, Thomas J.; Sechkar, Edward A.

    1998-01-01

    Metallized Teflon fluorinated ethylene propylene (FEP) thermal control insulation is mechanically degraded if exposed to a sufficient fluence of soft x-ray radiation. Soft x-ray photons (4-8 A in wavelength or 1.55 - 3.2 keV) emitted during solar flares have been proposed as a cause of mechanical properties degradation of aluminized Teflon FEP thermal control insulation on the Hubble Space Telescope (HST). Such degradation can be characterized by a reduction in elongation-to-failure of the Teflon FER Ground laboratory soft x-ray exposure tests of aluminized Teflon FEP were conducted to assess the degree of elongation degradation which would occur as a result of exposure to soft x-rays in the range of 3-10 keV. Tests results indicate that soft x-ray exposure in the 3-10 keV range, at mission fluence levels, does not alone cause the observed reduction in elongation of flight retrieved samples. The soft x-ray exposure facility design, mechanical properties degradation results and implications will be presented.

  12. Progress and prospects in soft x-ray holographic microscopy

    SciTech Connect

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

    1987-12-01

    We report some of the latest developments in x-ray holography experiments and make some speculations about the limits of performance of the approaches currently in use. We also make some suggestions about where the technique can (and cannot) go in the future. 32 refs., 5 figs., 1 tab.

  13. Soft X-ray astronomy using grazing incidence optics

    NASA Technical Reports Server (NTRS)

    Davis, John M.

    1989-01-01

    The instrumental background of X-ray astronomy with an emphasis on high resolution imagery is outlined. Optical and system performance, in terms of resolution, are compared and methods for improving the latter in finite length instruments described. The method of analysis of broadband images to obtain diagnostic information is described and is applied to the analysis of coronal structures.

  14. Studying Nanoscale Magnetism and its Dynamics with Soft X-ray Microscopy

    SciTech Connect

    Mccall, Monnikue M; Fischer, Peter

    2008-05-01

    Magnetic soft X-ray microscopy allows for imaging magnetic structures at a spatial resolution down to 15nm and a time resolution in the sub-100ps regime. Inherent elemental specificity can be used to image the magnetic response of individual components such as layers in multilayered systems. This review highlights current achievements and discusses the future potential of magnetic soft X-ray microscopy at fsec X-ray sources where snapshot images of ultrafast spin dynamics with a spatial resolution below 10nm will become feasible.

  15. Lensless Diffractive Imaging Using Tabletop Coherent High-Harmonic Soft-X-Ray Beams

    SciTech Connect

    Sandberg, Richard L.; Paul, Ariel; Raymondson, Daisy A.; Haedrich, Steffen; Gaudiosi, David M.; Holtsnider, Jim; Tobey, Ra'anan I.; Cohen, Oren; Murnane, Margaret M.; Kapteyn, Henry C.; Song, Changyong; Miao Jianwei; Liu Yanwei; Salmassi, Farhad

    2007-08-31

    We present the first experimental demonstration of lensless diffractive imaging using coherent soft x rays generated by a tabletop soft-x-ray source. A 29 nm high harmonic beam illuminates an object, and the subsequent diffraction is collected on an x-ray CCD camera. High dynamic range diffraction patterns are obtained by taking multiple exposures while blocking small-angle diffraction using beam blocks of varying size. These patterns reconstruct to images with 214 nm resolution. This work demonstrates a practical tabletop lensless microscope that promises to find applications in materials science, nanoscience, and biology.

  16. Progress in compact soft x-ray lasers and their applications

    SciTech Connect

    Suckewer, S.; Skinner, C.H.

    1995-01-01

    The ultra-high brightness and short pulse duration of soft x-ray lasers provide unique advantages for novel applications. A crucial factor in the availability of these devices is their scale and cost. Recent breakthroughs in this field has brought closer the advent of table-top devices, suitable for applications to fields such as x-ray microscopy, chemistry, material science, plasma diagnostics, and lithography. In this article we review recent progress in the development of compact (table-top) soft x-ray lasers.

  17. Omega Dante soft x-ray power diagnostic component calibration at the National Synchrotron Light Source

    SciTech Connect

    Campbell, K.M.; Weber, F.A.; Dewald, E.L.; Glenzer, S.H.; Landen, O.L.; Turner, R.E.; Waide, P.A.

    2004-10-01

    The Dante soft x-ray spectrometer, installed on the Omega laser facility at the Laboratory for Laser Energetics, University of Rochester, is a 12-channel filter-edge defined soft x-ray power diagnostic. It is used to measure the spectrally resolved, absolute flux from direct drive, indirect drive (hohlraums) and other plasma sources. Dante component calibration efforts using two beam lines, U3C (50 eV-1 keV) and X8A (1-6 keV) at the National Synchrotron Light Source have been implemented to improve the accuracy of these measurements. We have calibrated metallic vacuum x-ray diodes, mirrors and filters.

  18. Soft X-ray production by photon scattering in pulsating binary neutron star sources

    NASA Technical Reports Server (NTRS)

    Bussard, R. W.; Meszaros, P.; Alexander, S.

    1985-01-01

    A new mechanism is proposed as a source of soft (less than 1 keV) radiation in binary pulsating X-ray sources, in the form of photon scattering which leaves the electron in an excited Landau level. In a plasma with parameters typical of such sources, the low-energy X-ray emissivity of this mechanism far exceeds that of bremsstrahlung. This copious source of soft photons is quite adequate to provide the seed photons needed to explain the power-law hard X-ray spectrum by inverse Comptonization on the hot electrons at the base of the accretion column.

  19. An extreme ultraviolet telescope with no soft X-ray response

    NASA Technical Reports Server (NTRS)

    Finley, David S.; Jelinsky, Patrick; Bowyer, Stuart; Malina, Roger F.

    1986-01-01

    While EUV grazing incidence telescopes of conventional design exhibit a substantial X-ray response as well as an extreme UV response, and existing bandpass filters for the transmission of radiation longward of 400 A also transmit soft X-rays, the grazing incidence telescope presented suppresses this soft X-ray throughput through the incorporation of a Wolter Schwarzschild Type II mirror with large graze angles. The desirable features of an EUV photometric survey telescope are retained. An instrument of this design will be flown on the EUE mission, in order to make a survey of the sky at wavelengths longer than 400 A.

  20. The X-ray eclipse geometry of the super-soft X-ray source CAL 87

    SciTech Connect

    Ribeiro, T.; Lopes de Oliveira, R.

    2014-09-01

    We explore XMM-Newton observations of the eclipsing super-soft X-ray source CAL 87 in order to map the accretion structures of the system. Indirect imaging techniques were applied in X-ray light curves to provide eclipse maps. The surface brightness distribution exhibits an extended and symmetric emission, and a feature is revealed from the hardest X-rays that is likely due to a bright spot. A rate of P-dot =(+6±2)×10{sup −10} for changes in the orbital period of the system was derived from the eclipses. There is no significant variation of the emission lines even during eclipses, arguing that the lines are formed in an extended region. The continuum emission dominates the decrease in flux that is observed during eclipses. The O VIII Lyα line reveals a broadening velocity that is estimated to be 365{sub −69}{sup +65} km s{sup –1} (at 1σ), marginal evidence for asymmetry in its profile, and sometimes shows evidence of double-peaked emission. Together, the results support that the wind-driven mass transfer scenario is running in CAL 87.

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

    NASA Astrophysics Data System (ADS)

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

    2014-10-01

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

  2. No pain: no gain: The complex art of soft x-ray laser target design and analysis

    SciTech Connect

    Rosen, M.D.; London, R.A.; Hagelstein, P.L.; Maxon, M.S.; Eder, D.C.; Whitten, B.L.; Chen, M.H.; Nash, J.K.; Schofield, J.H.; Hazi, A.U.; and others

    1988-08-01

    We review our methodologies in the design and analysis of soft x-ray laser experiments. We convolve large scale 2-D hydro code output with detailed atomic data bases in a kinetics code with 1-D or 2-D line transfer. The time and space dependent level population data is then post processed further with a beam transport code, including refraction, to predict actual experimental results. While mysteries do remain, we present many examples that show how this complex modeling procedure is crucial in explaining experimental results.

  3. No pain-no gain: The complex art of soft x-ray laser target design and analysis

    SciTech Connect

    Rosen, M.D.; London, R.A.; Hagelstein, P.L.; Maxon, M.S.; Eder, D.C.; Whitten, B.L.; Chen, M.H.; Nash, J.K.; Scofield, J.H.; Hazi, A.U.

    1988-01-12

    We review our methodologies in the design and analysis of soft x-ray laser experiments. We convolve large-scale 2-D hydro code output with detailed atomic data bases in a kinetics code with 1-D or 2-D line transfer. The time and space dependent level population data is then post processed further with a beam transport code, including refraction, to predict actual experimental results. While mysteries do remain, we present many examples that show how this complex modeling procedure is crucial in explaining experimental results. 23 refs., 8 figs., 1 tab.

  4. Soft X-ray observations of the interacting galaxies NGC 1808 and NGC 1792

    NASA Technical Reports Server (NTRS)

    Dahlem, Michael; Hartner, Gisela D.; Junkes, Norbert

    1994-01-01

    The soft X-ray emission from both galaxies NGC 1808 and NGC 1792, which we investigated using the ROSAT HRI and Position Sensitive Proportional Counter (PSPC), comes most probably from X-ray binaries and/or from hot ionized gas in powerful supernovae and supernova remnants. The distribution of the soft X-ray emission in NGC 1808, which is very well correlated with the distribution of 'radio knots' in the central starburst, suggests that hot gas dominates the emission in the ROSAT band. This is consistent with the results of PSPC observations by Junkes et al. The total soft X-ray luminosity in the ROSAT band of NGC 1808 of 1.2 x 10(exp 41) ergs/s is relatively high compared with other nearby starburst galaxies. Soft X-ray emission of diffuse hot ionized gas that is associated with the outflow traced by the conspicuous dust filaments protruding from the plane has been detected. Its luminosity in the ROSAT band is greater than or equal to 3 x 10(exp 39) ergs/s, i.e., several percent of the total soft X-ray luminosity. Thus, NGC 1808 is another example for a 'superwind' galaxy. The soft X-ray radiation from NGC 1792 is more likely to be dominated by a population of high-mass X-ray binaries or young powerful supernovae which are associated with the high-level star formation going on in the very prominent H II regions along its spiral arms, with possibly an additional contribution of diffuse hot ionized gas. The soft X-ray luminosities of individual sources lie in the range of 5 x 10(exp 38) to 2.7 x 10(exp 39) ergs/s, thus exceeding by far the Eddington luminosity of an accreting neutron star. The peaks of some of these soft X-ray luminous sources are offset with respect to the H II regions by a few hundred parsecs. Accordingly, if the soft X-ray sources should originate from the H II regions, their relative velocities with respect to the ambient medium have to be as high as approximately 100 km/s.

  5. 2D and 3D Refraction Based X-ray Imaging Suitable for Clinical and Pathological Diagnosis

    SciTech Connect

    Ando, Masami; Bando, Hiroko; Ueno, Ei

    2007-01-19

    The first observation of micro papillary (MP) breast cancer by x-ray dark-field imaging (XDFI) and the first observation of the 3D x-ray internal structure of another breast cancer, ductal carcinoma in-situ (DCIS), are reported. The specimen size for the sheet-shaped MP was 26 mm x 22 mm x 2.8 mm, and that for the rod-shaped DCIS was 3.6 mm in diameter and 4.7 mm in height. The experiment was performed at the Photon Factory, KEK: High Energy Accelerator Research Organization. We achieved a high-contrast x-ray image by adopting a thickness-controlled transmission-type angular analyzer that allows only refraction components from the object for 2D imaging. This provides a high-contrast image of cancer-cell nests, cancer cells and stroma. For x-ray 3D imaging, a new algorithm due to the refraction for x-ray CT was created. The angular information was acquired by x-ray optics diffraction-enhanced imaging (DEI). The number of data was 900 for each reconstruction. A reconstructed CT image may include ductus lactiferi, micro calcification and the breast gland. This modality has the possibility to open up a new clinical and pathological diagnosis using x-ray, offering more precise inspection and detection of early signs of breast cancer.

  6. 2D and 3D Refraction Based X-ray Imaging Suitable for Clinical and Pathological Diagnosis

    NASA Astrophysics Data System (ADS)

    Ando, Masami; Bando, Hiroko; Chen, Zhihua; Chikaura, Yoshinori; Choi, Chang-Hyuk; Endo, Tokiko; Esumi, Hiroyasu; Gang, Li; Hashimoto, Eiko; Hirano, Keiichi; Hyodo, Kazuyuki; Ichihara, Shu; Jheon, SangHoon; Kim, HongTae; Kim, JongKi; Kimura, Tatsuro; Lee, ChangHyun; Maksimenko, Anton; Ohbayashi, Chiho; Park, SungHwan; Shimao, Daisuke; Sugiyama, Hiroshi; Tang, Jintian; Ueno, Ei; Yamasaki, Katsuhito; Yuasa, Tetsuya

    2007-01-01

    The first observation of micro papillary (MP) breast cancer by x-ray dark-field imaging (XDFI) and the first observation of the 3D x-ray internal structure of another breast cancer, ductal carcinoma in-situ (DCIS), are reported. The specimen size for the sheet-shaped MP was 26 mm × 22 mm × 2.8 mm, and that for the rod-shaped DCIS was 3.6 mm in diameter and 4.7 mm in height. The experiment was performed at the Photon Factory, KEK: High Energy Accelerator Research Organization. We achieved a high-contrast x-ray image by adopting a thickness-controlled transmission-type angular analyzer that allows only refraction components from the object for 2D imaging. This provides a high-contrast image of cancer-cell nests, cancer cells and stroma. For x-ray 3D imaging, a new algorithm due to the refraction for x-ray CT was created. The angular information was acquired by x-ray optics diffraction-enhanced imaging (DEI). The number of data was 900 for each reconstruction. A reconstructed CT image may include ductus lactiferi, micro calcification and the breast gland. This modality has the possibility to open up a new clinical and pathological diagnosis using x-ray, offering more precise inspection and detection of early signs of breast cancer.

  7. Synchrotron x-ray photoemission study of soft x-ray processed ultrathin glycine-water ice films

    SciTech Connect

    Tzvetkov, George; Netzer, Falko P.

    2011-05-28

    Ultrathin glycine-water ice films have been prepared in ultrahigh vacuum by condensation of H{sub 2}O and glycine at 90 K on single crystalline alumina surfaces and processed by soft x-ray (610 eV) exposure for up to 60 min. The physicochemical changes in the films were monitored using synchrotron x-ray photoemission spectroscopy. Two films with different amounts of H{sub 2}O have been considered in order to evaluate the influence of the water ice content on the radiation-induced effects. The analysis of C1s, N1s, and O1s spectral regions together with the changes in the valence band spectra indicates that amino acid degradation occurs fast mainly via decarboxylation and deamination of pristine molecules. Enrichment of the x-ray exposed surfaces with fragments with carbon atoms without strong electronegative substituents (C-C and C-H) is documented as well. In the thinner glycine-water ice film (six layers of glycine + six layers of water) the 3D ice suffers strongly from the x-rays and is largely removed from the sample. The rate of photodecomposition of glycine in this film is about 30% higher than for glycine in the thicker film (6 layers of glycine + 60 layers of water). The photoemission results suggest that the destruction of amino acid molecules is caused by the direct interaction with the radiation and that no chemical attack of glycine by the species released by water radiolysis is detected.

  8. Ultrastructural and elemental imaging of biological specimens by soft x-ray contact microscopy

    SciTech Connect

    Panessa, B.J.; Hoffman, P. . Dept. of Orthopedics); Warren, J.B. ); Feder, R.; Sayre, D. . Thomas J. Watson Research Center)

    1980-01-01

    Soft X-ray contact microscopy offers a means of visualizing unstained as well as stained biological materials at better than 6 nm resolution. Soft X-ray imaging depends on differential absorption of incident soft (1--10nm wavelength) X-rays by the endogenous elements within a specimen. The advantages of using soft X-rays for imaging are: (1) reduced specimen damage during exposure; (2) ability to image hydrated specimens at atmospheric pressure; (3) ability to image specimens ranging in thickness from less than 40 nm to as much as 10{mu}m; and (4) ability to map the elemental composition of the specimen through observation of the differential absorption of properly chosen incident x-ray wavelengths. This paper explains the principles of image formation and demonstrates the use of soft X-ray contact microscopy with biological samples which could not readily be imaged in their natural form using conventional electron microscopy methods. Data are also presented on the recognition of compositional features in histochemically treated articular joint tissues. 30 refs., 15 figs.

  9. On the Lack of a Soft X-Ray Excess from Clusters of Galaxies

    NASA Astrophysics Data System (ADS)

    Bregman, Joel N.; Lloyd-Davies, Edward J.

    2006-06-01

    A soft X-ray excess has been claimed to exist in and around a number of galaxy clusters, and this emission has been attributed to the warm-hot intergalactic medium that may constitute most of the baryons in the local universe. We have reexamined a study of the XMM-Newton observations on this topic by Kaastra and coworkers and find that the X-ray excess (or deficit) depends on Galactic latitude and appears to be most closely related to the surface brightness of the 1/4 keV emission, which is largely due to emission from the local hot bubble and the halo of the Milky Way. We suggest that the presence of the soft X-ray excess is due to incorrect subtraction of the soft X-ray background. An analysis is performed for which we choose a 1/4 keV background that is similar to the background near the cluster (and a similar H I column). We find that the soft X-ray excess largely disappears using our background subtraction and conclude that these soft X-ray excesses are not associated with the target clusters. We also show that the detections of ``redshifted'' O VII lines claimed by Kaastra and coworkers are correlated with solar system charge exchange emission, suggesting that they are not extragalactic either.

  10. Soft X-ray characterisation of the long-term properties of supergiant fast X-ray transients

    NASA Astrophysics Data System (ADS)

    Romano, P.; Ducci, L.; Mangano, V.; Esposito, P.; Bozzo, E.; Vercellone, S.

    2014-08-01

    Context. Supergiant fast X-ray transients (SFXTs) are high mass X-ray binaries (HMXBs) that are characterised by a hard X-ray (≥ 15 keV) flaring behaviour. These flares reach peak luminosities of 1036-1037 erg s-1 and last a few hours in the hard X-rays. Aims: We investigate the long-term properties of SFXTs by examining the soft (0.3-10 keV) X-ray emission of the three least active SFXTs in the hard X-ray and by comparing them with the remainder of the SFXT sample. Methods: We performed the first high-sensitivity soft X-ray long-term monitoring with Swift/XRT of three relatively unexplored SFXTs, IGR J08408-4503, IGR J16328-4726, and IGR J16465-4507, whose hard X-ray duty cycles are the lowest measured among the SFXT sample. We assessed how long each source spends in each flux state and compared their properties with those of the prototypical SFXTs. Results: The behaviour of IGR J08408-4503 and IGR J16328-4726 resembles that of other SFXTs, and it is characterised by a relatively high inactivity duty cycle (IDC) and pronounced dynamic range (DR) in the X-ray luminosity. We found DR ~ 7400, IDC ~ 67% for IGR J08408-4503, and DR ~ 750, IDC ~ 61% for IGR J16328-4726 (in all cases the IDC is given with respect to the limiting flux sensitivity of XRT, that is 1-3 × 10-12 erg cm-2 s-1). In common with all the most extreme SFXT prototypes (IGR J17544-2619, XTE J1739-302, and IGR J16479-4514), IGR J08408-4503 shows two distinct flare populations. The first one is associated with the brightest outbursts (X-ray luminosity LX ≳ 1035 - 36 erg s-1), while the second comprises dimmer events with typical luminosities of LX ≲ 1035 erg s-1. This double-peaked distribution of the flares as a function of the X-ray luminosity seems to be a ubiquitous feature of the extreme SFXTs. The lower DR of IGR J16328-4726 suggests that this is an intermediate SFXT. IGR J16465-4507 is characterised by a low IDC ~ 5% and a relatively narrow DR ~ 40, reminiscent of classical supergiant

  11. Time-resolved near-edge x-ray absorption fine structure spectroscopy on photo-induced phase transitions using a tabletop soft-x-ray spectrometer

    NASA Astrophysics Data System (ADS)

    Grossmann, P.; Rajkovic, I.; Moré, R.; Norpoth, J.; Techert, S.; Jooss, C.; Mann, Klaus

    2012-05-01

    We present a table-top soft-x-ray spectrometer for the wavelength range λ = 1-5 nm based on a stable laser-driven x-ray source, making use of a gas-puff target. With this setup, optical light-pump/soft-x-ray probe near-edge x-ray absorption fine structure (NEXAFS) experiments with a temporal resolution of about 230 ps are feasible. Pump-probe NEXAFS measurements were carried out in the "water-window" region (2.28 nm-4.36 nm) on the manganite Pr0.7Ca0.3MnO3, investigating diminutive changes of the oxygen K edge that derive from an optically induced phase transition. The results show the practicability of the table-top soft-x-ray spectrometer on demanding investigations so far exclusively conducted at synchrotron radiation sources.

  12. Streak cameras for soft x-ray and optical radiation

    SciTech Connect

    Medecki, H.

    1983-09-01

    The principal component of a streak camera is the image converter tube. A slit-shaped photocathode transforms the radiation into a proportional emission of electrons. An electron - optics arrangement accelerates the electrons and projects them into a phosphor screen creating the image of the slit. A pair of deflection plates deflects the electronic beam along a direction perpendicular to the main dimension of the slit. Different portions of the phosphor screen show the instantaneous image of the slit with brightness proportional to the number of emitted electrons and, consequently, to the intensity of the radiation. For our x-ray streak cameras, we use the RCA C73435A image conventer tube intended for the measurement of the radiation of light and modified to have an x-ray sensitive photocathode. Practical considerations lead to the use of transparent rather than reflecting photocathodes. Several of these camera tubes are briefly described.

  13. Soft x-ray holographic computerized tomography imaging: experimental research

    NASA Astrophysics Data System (ADS)

    Zhang, Yuxuan; Jiang, Shiping; Zhang, Xinyi

    2003-03-01

    A high-resolution three-dimensional (3D) imaging technology has been developed, which is a combination of x-ray holography and computerized tomography (CT) technology called holographic computerized tomography (HCT). The theory and experimental techniques on biological specimens with the use of synchrotron radiation are discussed. Projections at different angles are reconstructed with the numerical method of in-line holography, and then the reconstructed data with a higher lateral resolution are used to restore the 3D image by the CT technique. With this method, the degradation caused by the diffraction of x rays is canceled, and 3D images with high resolution of micrometer magnitude in both the lateral and the longitudinal directions are obtained.

  14. The Soft X-Ray Emission Component of Spiral Galaxies

    NASA Technical Reports Server (NTRS)

    Fabbiano, Giuseppina

    1998-01-01

    Work included the analysis of the HRJ observations of the Sombrero galaxy (Fabbiano and Juda) published in Ap.J. This paper discussed the discovery of a point-like x-ray source at the nucleus of the galaxy, which is suspected to host a massive black hole. More work was done on the analysis of the Observation of M94 in support of an AXAF proposal. We have also analyzed the M81 data by adding to our observation the entire set of the archival ROSAT data. We plan to write up the results for publication. Both galaxies have nuclei optically similar to that of the Sombrero galaxy. The nucleus of M81 is a known x-ray source. The M94 data has revealed a point-like nuclear source superposed on more diffuse emission.

  15. In-situ observations of catalytic surface reactions with soft x-rays under working conditions

    NASA Astrophysics Data System (ADS)

    Toyoshima, Ryo; Kondoh, Hiroshi

    2015-03-01

    Catalytic chemical reactions proceeding on solid surfaces are an important topic in fundamental science and industrial technologies such as energy conversion, pollution control and chemical synthesis. Complete understanding of the heterogeneous catalysis and improving its efficiency to an ultimate level are the eventual goals for many surface scientists. Soft x-ray is one of the prime probes to observe electronic and structural information of the target materials. Most studies in surface science using soft x-rays have been performed under ultra-high vacuum conditions due to the technical limitation, though the practical catalytic reactions proceed under ambient pressure conditions. However, recent developments of soft x-ray based techniques operating under ambient pressure conditions have opened a door to the in-situ observation of materials under realistic environments. The near-ambient-pressure x-ray photoelectron spectroscopy (NAP-XPS) using synchrotron radiation enables us to observe the chemical states of surfaces of condensed matters under the presence of gas(es) at elevated pressures, which has been hardly conducted with the conventional XPS technique. Furthermore, not only the NAP-XPS but also ambient-pressure compatible soft x-ray core-level spectroscopies, such as near-edge absorption fine structure (NEXAFS) and x-ray emission spectroscopy (XES), have been significantly contributing to the in-situ observations. In this review, first we introduce recent developments of in-situ observations using soft x-ray techniques and current status. Then we present recent new findings on catalytically active surfaces using soft x-ray techniques, particularly focusing on the NAP-XPS technique. Finally we give a perspective on the future direction of this emerging technique.

  16. OSO-8 soft X-ray experiment (Wisconsin)

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Information for operating and reducing data from the experiment which was designed to map low energy X-ray background emissions from 130 eV to 35 keV is presented. The detectors, counters, data system, and the gas system are discussed along with the functional operation of the subsystems. A command list indicating preconditions and resulting telemetry response for each command is included.

  17. Design considerations for soft X-ray television imaging detectors

    NASA Technical Reports Server (NTRS)

    Kalata, Kenneth; Golub, Leon

    1988-01-01

    Television sensors for X-rays can be coupled to converters and image intensifiers to obtain active areas, high flux capabilities, quantum efficiency, high time resolution, or ease of construction and operation that may not be obtained with a directly illuminated sensor. A general purpose system which makes use of these capabilities for a number of applications is decribed. Some of the performance characteristics of this type of system are examined, and the expected future developments for such systems are briefly addressed.

  18. Incoherent imaging with the soft X-ray microscope

    PubMed

    Burge; Yuan; Morrison; Charalambous; Browne; An

    2000-05-01

    The imaging characteristics for X-ray wavelengths in the "water window" under incoherent imaging conditions (large detector aperture) are examined for the King's College London scanning transmission X-ray microscope with zone-plate objective installed at the Daresbury (UK) synchrotron. The principal consideration was to express image theory, incorporating wave aberrations and apodised zone plates, and to apply the theory to experimental data. Comparisons are made, showing reasonable agreement, for a range of defocus values and two wavelengths. Due to problems in fabrication it was necessary to determine the effective, or operational, zone-plate parameters (radius of outermost active zone rN, width of outermost active zone drN); this was accomplished by through-focus series. Calculated point spread functions were used to deblurr images, in through-focus series of two-dimensional scanned X-ray images of specimen holes and test grating patterns. Significant contrast enhancement is achieved after deconvolution with a best point-to-point resolution of about 35 nm. PMID:10805394

  19. Data processing for soft X-ray diagnostics based on GEM detector measurements for fusion plasma imaging

    NASA Astrophysics Data System (ADS)

    Czarski, T.; Chernyshova, M.; Pozniak, K. T.; Kasprowicz, G.; Byszuk, A.; Juszczyk, B.; Wojenski, A.; Zabolotny, W.; Zienkiewicz, P.

    2015-12-01

    The measurement system based on GEM - Gas Electron Multiplier detector is developed for X-ray diagnostics of magnetic confinement fusion plasmas. The Triple Gas Electron Multiplier (T-GEM) is presented as soft X-ray (SXR) energy and position sensitive detector. The paper is focused on the measurement subject and describes the fundamental data processing to obtain reliable characteristics (histograms) useful for physicists. So, it is the software part of the project between the electronic hardware and physics applications. The project is original and it was developed by the paper authors. Multi-channel measurement system and essential data processing for X-ray energy and position recognition are considered. Several modes of data acquisition determined by hardware and software processing are introduced. Typical measuring issues are deliberated for the enhancement of data quality. The primary version based on 1-D GEM detector was applied for the high-resolution X-ray crystal spectrometer KX1 in the JET tokamak. The current version considers 2-D detector structures initially for the investigation purpose. Two detector structures with single-pixel sensors and multi-pixel (directional) sensors are considered for two-dimensional X-ray imaging. Fundamental output characteristics are presented for one and two dimensional detector structure. Representative results for reference source and tokamak plasma are demonstrated.

  20. Time-resolved soft X-ray microscopy of magnetic nanostructures at the P04 beamline at PETRA III

    NASA Astrophysics Data System (ADS)

    Wessels, P.; Ewald, J.; Wieland, M.; Nisius, T.; Abbati, G.; Baumbach, S.; Overbuschmann, J.; Vogel, A.; Neumann, A.; Viefhaus, J.; Oepen, H. P.; Meier, G.; Wilhein, T.; Drescher, M.

    2014-04-01

    We present first time-resolved measurements of a new mobile full-field transmission microscope [1] obtained at the soft X-ray beamline P04 at the high brilliance synchrotron radiation source PETRA III. A nanostructured magnetic permalloy (Ni80Fe20) sample can be excited by the magnetic field of a 400 ps full width at half maximum (FWHM) long electric current pulse in a coplanar waveguide. The full-field soft X-ray microscope successively probes the time evolution of the sample magnetization via X-ray magnetic circular dichroism (XMCD) [2] spectromicroscopy in a pump-probe scheme by varying the delay between pump and probe pulses electronically. Static and transient magnetic fields of a permanent magnet and a coil are available in the sample plane to reset the system and to provide external offset fields. The microscope generates a flat-top illumination field of 20 μm diameter by using a grating condenser [3] and the sample plane is directly imaged by a micro zone plate with 60 nm resolution onto a 2D gateable X-ray detector to select the particular bunch in the storage ring that contains the dynamic information. The setup is built into a mobile endstation vacuum system with in-house developed three-axis piezo motorized stages for high accuracy positioning of all microscopy-components inside the chambers.

  1. Persistence and change in the soft X-ray spectrum of the quasar PG 1211 + 143

    NASA Technical Reports Server (NTRS)

    Elvis, Martin; Wilkes, Belinda J.; Giommi, P.; Mcdowell, Jonathan

    1991-01-01

    The present study examines two Einstein and three Exosat observations of PG 1211 + 143 over a 6-yr baseline which show that strong steep-spectrum low-energy X-ray emission is a persistent feature of this quasar. Exosat observations of PG 1211 + 143 detected an increase of a factor of 2.3 in its steep soft X-ray flux during 18 days. It is concluded that the bulk of the soft X-ray emission of PG 1211 + 143 comes from a region less than 5 x 10 to the 16th cm across. In another interval of 193 days, the soft X-rays decreased by a factor of 3.7. In the same interval the hard X-rays decreased by a factor of 1.6 + or - 0.05, which suggests a connection between the two energy regimes and argues against variable absorption causing the soft X-ray variations. It is contended that in order to decrease in luminosity so rapidly, a thermal source in PG 1211 + 143 would have to be optically thick to both electron scattering and free-bound absorption.

  2. The soft X-ray excess in Einstein quasar spectra

    NASA Technical Reports Server (NTRS)

    Masnou, J. L.; Wilkes, B. J.; Elvis, M.; Mcdowell, J. C.; Arnaud, K. A.

    1992-01-01

    An SNR-limited subsample of 14 quasars from the Wilkes and Elvis (1987) sample is presently investigated for low-energy excess above a high-energy power law in the X-ray spectra obtained by the Einstein Imaging Proportional Counter. A significant excess that is 1-6 times as strong as the high-energy component at 0.2 keV is noted in eight of the 14 objects. In the case of 3C273, multiple observations show the excess to be variable.

  3. Soft X-ray search of centre of Cygnus Loop

    NASA Technical Reports Server (NTRS)

    Snyder, W. A.; Henry, R. C.; Charles, P. A.; Culhane, J. L.; Sanford, P. W.; Bleach, R.; Drake, J.

    1975-01-01

    Equipment on the Copernicus satellite has been used to search for evidence of a compact object in the center of the Cygnus Loop supernova remnant. Rocket measurements reported by Rappaport et al. (1973) indicate that a central object exists. However, the study conducted with the aid of the satellite was negative. This negative result could indicate that the X-ray source was simply not in its high-intensity mode at the time of observation, or could arise because the source is at some other location in the Loop.

  4. Discovery of Soft X-Ray Emission from Io, Europa and the Io Plasma Torus

    NASA Technical Reports Server (NTRS)

    Elsner, R. F.; Gladstone, G. R.; Waite, J. H.; Crary, F. J.; Howell, R. R.; Johnson, R. E.; Ford, P. G.; Metzger, A. E.; Hurley, K. C.; Feigelson, E. D.; Six, N. Frank (Technical Monitor)

    2001-01-01

    The Chandra X-ray Observatory observed the Jovian system for about 24 hours on 25-26 Nov 1999 with the Advanced CCD Imaging Spectrometer (ACIS), in support of the Galileo flyby of Io, and for about 10 hours on 18 Dec 2000 with the imaging array of the High Resolution Camera (HRC-I), in support of the Cassini flyby of Jupiter. Analysis of these data have revealed soft (0.25--2 keV) x-ray emission from the moons Io and Europa, probably Ganymede, and from the Io Plasma Torus (IPT). Bombardment by energetic (greater than 10 keV) H, O, and S ions from the region of the IPT seems the likely source of the x-ray emission from the Galilean moons. According to our estimates, fluorescent x-ray emission excited by solar x-rays is about an order of magnitude too weak even during flares from the active Sun to account for the observed x-ray flux from the IPT. Charge-exchange processes, previously invoked to explain Jupiter's x-ray aurora and cometary x-ray emission, and ion stripping by dust grains both fall by orders of magnitude. On the other hand, we calculate that bremsstrahlung emission of soft X-rays from non-thermal electrons in the few hundred to few thousand eV range accounts for roughly one third of the observed x-ray flux from the IPT. Extension of the far ultraviolet (FUV) IPT spectrum likely also contributes.

  5. Rigid 2D/3D registration of intraoperative digital x-ray images and preoperative CT and MR images

    NASA Astrophysics Data System (ADS)

    Tomazevic, Dejan; Likar, Bostjan; Pernus, Franjo

    2002-05-01

    This paper describes a novel approach to register 3D computed tomography (CT) or magnetic resonance (MR) images to a set of 2D X-ray images. Such a registration may be a valuable tool for intraoperative determination of the precise position and orientation of some anatomy of interest, defined in preoperative images. The registration is based solely on the information present in 2D and 3D images. It does not require fiducial markers, X-ray image segmentation, or construction of digitally reconstructed radiographs. The originality of the approach is in using normals to bone surfaces, preoperatively defined in 3D MR or CT data, and gradients of intraoperative X-ray images, which are back-projected towards the X-ray source. The registration is then concerned with finding that rigid transformation of a CT or MR volume, which provides the best match between surface normals and back projected gradients, considering their amplitudes and orientations. The method is tested on a lumbar spine phantom. Gold standard registration is obtained by fidicual markers attached to the phantom. Volumes of interest, containing single vertebrae, are registered to different pairs of X-ray images from different starting positions, chosen randomly and uniformly around the gold standard position. Target registration errors and rotation errors are in order of 0.3 mm and 0.35 degrees for the CT to X-ray registration and 1.3 mm and 1.5 degrees for MR to X-ray registration. The registration is shown to be fast and accurate.

  6. Observations of the structure and evolution of solar flares with a soft X-ray telescope

    NASA Technical Reports Server (NTRS)

    Vorpahl, J. A.; Gibson, E. G.; Landecker, P. B.; Mckenzie, D. L.; Underwood, J. M.

    1975-01-01

    Soft X ray flare events were observed with the S-056 X-ray telescope that was part of the ATM complement of instruments aboard SKYLAB. Analyses of these data are reported. The observations are summarized and a detailed discussion of the X-ray flare structures is presented. The data indicated that soft X-ray emitted by a flare come primarily from an intense well-defined core surrounded by a region of fainter, more diffuse emission. An analysis of flare evolution indicates evidence for preliminary heating and energy release prior to the main phase of the flare. Core features are found to be remarkably stable and retain their shape throughout a flare. Most changes in the overall configuration seem to be result of the appearance, disappearance or change in brightness of individual features, rather than the restructuring or reorientation of these features. Brief comparisons with several theories are presented.

  7. Interrelation of soft and hard X-ray emissions during solar flares. I - Observations

    NASA Technical Reports Server (NTRS)

    Winglee, R. M.; Kiplinger, A. L.; Zarro, D. M.; Dulk, G. A.; Lemen, J. R.

    1991-01-01

    The interrelation between the acceleration and heating of electrons and ions during impulsive solar flares is determined on the basis of simulataneous observations of hard and soft X-ray emission from the Solar Maximum Mission at high time resolution (6 s). For all the flares, the hard X-rays are found to have a power-law spectrum which breaks down during the rise phase and beginning of the decay phase. After that, the spectrum changes to either a single power law or a power law that breaks up at high energies. The characteristics of the soft X-ray are found to depend on the flare position. It is suggested that small-scale quasi-static electric fields are important for determining the acceleration of the X-ray-producing electrons and the outflowing chromospheric ions.

  8. Evaluating the quality of images produced by soft X-ray units.

    PubMed

    Bradley, D A; Wong, C S; Ng, K H

    2000-01-01

    For broad-beam soft X-ray sources, assessment of the quality of image produced by such units is made complex by the low penetration capabilities of the radiation. In the present study we have tested the utility of several types of test tool, some of which have been fabricated by us, as part of an effort to evaluate several key image defining parameters. These include the film characteristic, focal-spot size, image resolution and detail detectability. The two sources of X-rays used in present studies were the University of Malaya flash X-ray device (UMFX1) and a more conventional soft X-ray tube (Softex, Tokyo), the latter operating at peak accelerating potentials of 20 kVp. We have established, for thin objects, that both systems produce images of comparable quality and, in particular, objects can be resolved down to better than 45 microm. PMID:11003508

  9. Using Resonant Soft X-rays to Reveal Internal Organic Thin Film Structure

    NASA Astrophysics Data System (ADS)

    Gann, Eliot

    This dissertation details the establishment and expansion of resonant soft X-ray scattering techniques to reveal the internal structure of organic thin films. These films are increasingly important in numerous electronic systems, including organic thin film transistors, organic photovoltaics, and organic light emitting diodes. These devices use the electrical properties of polymers to respectively turn on and off conduction, turn light into electricity, and create light. The performance of each of these systems depends critically on their physical structure but unfortunately, traditional techniques fail to adequately characterize that structure. This dissertation will explore the use of soft X-ray scattering to reveal the mesoscale structure or organic electronic devices. This begins with an overview of the field to make the case for soft X-rays being an appropriate and novel tool. Next, to explain how to collect accurate soft X-ray scattering, the development of a new and unique soft X-ray scattering facility will be presented. Having the tools, the next step is to develop scattering theories and models for understanding and correctly analyzing scattering from these complicated devices. This includes development and comparison of analysis techniques and theory to simulate scattering. This simulation system is then used in the development of a theory to understand the novel phenomenon of anisotropic X-ray scattering from isotropic organic samples. Finally, I will describe the development and first use of a method able to simultaneously measure size scales and chemical structure with depth sensitivity in thin films: Grazing Resonant Soft X-ray Scattering. This work provides valuable understanding and tools to the field of materials characterization, opening up new opportunities for principled design of organic electronics.

  10. The origin of the soft X-ray excess in the Seyfert 2 galaxy NGC 2110

    NASA Technical Reports Server (NTRS)

    Weaver, K. A.; Mushotzky, R. F.; Serlemitsos, P. J.; Wilson, A. S.; Elvis, M.; Briel, U.

    1995-01-01

    We present and discuss an X-ray image and a medium-resolution X-ray spectrum of the Seyfert 2 galaxy NGC 2110 obtained with the high-resolution imager (HRI) on ROSAT (0.1-2.4 keV) and Goddard's Broad Band X-ray Telescope (BBXRT; 0.3-11 keV), respectively. Spatially resolved soft X-ray emission, which peaks 4 arcsecs to the north of the nucleus and near the position of the highest excitation optical emission line gas is seen in the HRI observation. The extent has a flux of approximately 3 x 10(exp -13) ergs/sq cm/s and accounts for 11% +/- 3% of the total 0.1-2.4 keV flux. To model the BBXRT spectrum, a soft excess component is required which has a flux of approximately 3.5 x 10(exp -13) ergs/sq cm/s and accounts for approximately 14% +/- 6% of the total 0.1-2.4 keV flux. In addition, BBXRT confirms the presence of an approximately 175 eV equivalent width Fe K alpha flourescence line in NGC 2110. Because of the good agreement between their fluxes, we propose that the soft excess in NGC 2110 is due to leakage of the X-ray continuum through a patchy absorber. The temperature of the gas responsible for the soft excess is too high to be accounted for by local shock heating. In order to explain the soft excess and extent as either scattered continuum X-rays or flourescence from gas photoionized by the nuclear source, the hard X-rays must be emitted anisotropically. However, the soft excess and extent can be well modeled as thermal emission from a hot, outflowing wind, which may also be responsible for confirming at least some portion of the optical narrow line-emitting clouds.

  11. Time-resolved Soft X-Ray Imaging (SXRI) diagnostic for use at the NIF and OMEGA lasers (version 2)

    SciTech Connect

    Schneider, M B; Holder, J P; James, D L; Bruns, H C; Celeste, J R; Compton, S; Costa, R L; Ellis, A D; Emig, J A; Hargrove, D; Kalantar, D H; MacGowan, B J; Power, G D; Sorce, C; Rekow, V; Widmann, K; Young, B K; Young, P E; Garcia, O F; McKenney, J; Haugh, M; Goldin, F; MacNeil, L P; Cone, K

    2006-07-21

    The soft x-ray imager (SXRI) built for the first experiments at the National Ignition Facility (NIF) has four soft x-ray channels and one hard x-ray channel. The SXRI is a snout that mounts to a four strip gated imager. This produces four soft x-ray images per strip, which can be separated in time by {approx}60psec. Each soft x-ray channel consists of a mirror plus a filter. The diagnostic was used to study x-ray burnthrough of hot hohlraum targets at the NIF and OMEGA lasers. The SXRI snout design and issues involved in selecting the desired soft x-ray channels are discussed.

  12. Time-resolved Soft X-Ray Imaging (SXRI) diagnostic for use at the NIF and OMEGA lasers

    SciTech Connect

    Schneider, M; Holder, J; James, D; Bruns, H; Celeste, J; Compton, S; Costa, R; Ellis, A; Emig, J; Hargrove, D; Kalantar, D; MacGowan, B; Power, G; Sorce, C; Rekow, V; Widmann, K; Young, B; Young, P; Garcia, O; McKenney, J; Haugh, M; Goldin, F; MacNeil, L; Cone, K

    2006-05-04

    The soft x-ray imager (SXRI) built for the first experiments at the National Ignition Facility (NIF) has four soft x-ray channels and one hard x-ray channel. The SXRI is a snout that mounts to a four strip gated imager. This produces four soft x-ray images per strip, which can be separated in time by {approx}60psec. Each soft x-ray channel consists of a mirror plus a filter. The diagnostic was used to study x-ray burnthrough of hot hohlraum targets at the NIF and OMEGA lasers. The SXRI snout design and issues involved in selecting the desired soft x-ray channels are discussed.

  13. Soft x-ray imager (SXI) onboard ASTRO-H

    NASA Astrophysics Data System (ADS)

    Tsunemi, Hiroshi; Hayashida, Kiyoshi; Tsuru, Takeshi Go; Dotani, Tadayasu; Hiraga, Junko S.; Anabuki, Naohisa; Bamba, Aya; Hatsukade, Isamu; Kohmura, Takayoshi; Mori, Koji; Murakami, Hiroshi; Nakajima, Hiroshi; Ozaki, Masanobu; Uchida, Hiroyuki; Yamauchi, Makoto

    2010-07-01

    We are designing an X-ray CCD camera (SXI) for ASTRO-H, including many new items. We have developed the CCD, CCD-NeXT4, that is a P-channel type CCD. It has a thick depletion layer of 200μm with an imaging area of 30mm square. Since it is back-illuminated, it has a good low energy response and is robust against the impact of micro-meteorites. We will employ 4 chips to cover the area of 60mm square. A mechanical rather than peltier cooler will be employed so that we can cool the CCD to -120°C. We will also introduce an analog ASIC that is placed very close to the CCD. It performs well, having a similar noise level to that assembled by using individual parts used on SUZAKU. We also employ a modulated X-ray source (MXS), that improves the accuracy of the calibration. The SXI will have one of the largest SΩ among various satellites.

  14. The Onset Phase of "Soft" X-ray Transients

    NASA Technical Reports Server (NTRS)

    Swank, Jean Hebb; Shaposhnikov, N.; Shrader, C. R.; Rupen, M. P.; Beckmann, V.; Markwardt, C. B.; Smith, D. A.

    2006-01-01

    Transient outbursts of black holes and neutron stars in X-ray binaries with low-mass companions start with a flickering hard power-law flux that contains a low frequency quasi-periodic oscillation (QPO). The frequency of the QPO may reflect the outer boundary of the coronal emission and its inward motion toward the compact object. It has also been proposed that the hard flux is related to the base of a radio emitting outflow or compact jet. We had detailed observations of the beginning of the 2005 outburst of GRO J165.5-40 with RXTE, INTEGRAL, the VLA and ROTSE. We use the X-ray, radio, and optical results in the context of these models to address their applicability to the onset of the outburst and to specify the physical parameters. Decline of the radio flux as both the power-law and disk flux increased constrains the amount of synchrotron self-Compton emission. Values are compared to those of other black hole and neutron star transients. We are glad to acknowledge support by a NASA INTEGRAL Guest Observer Grant and by the UTE project, NRAO, and ROTSE.

  15. STELLAR WIND INDUCED SOFT X-RAY EMISSION FROM CLOSE-IN EXOPLANETS

    SciTech Connect

    Kislyakova, K. G.; Lammer, H.; Fossati, L.; Johnstone, C. P.; Holmström, M.; Zaitsev, V. V.

    2015-01-30

    In this Letter, we estimate the X-ray emission from close-in exoplanets. We show that the Solar/Stellar Wind Charge Exchange Mechanism (SWCX), which produces soft X-ray emission, is very effective for hot Jupiters. In this mechanism, X-ray photons are emitted as a result of the charge exchange between heavy ions in the solar wind and the atmospheric neutral particles. In the solar system, comets produce X-rays mostly through the SWCX mechanism, but it has also been shown to operate in the heliosphere, in the terrestrial magnetosheath, and on Mars, Venus, and the Moon. Since the number of emitted photons is proportional to the solar wind mass flux, this mechanism is not very effective for the solar system giants. Here we present a simple estimate of the X-ray emission intensity that can be produced by close-in extrasolar giant planets due to charge exchange with the heavy ions of the stellar wind. Using the example of HD 209458b, we show that this mechanism alone can be responsible for an X-ray emission of ≈10{sup 22} erg s{sup –1}, which is 10{sup 6} times stronger than the emission from the Jovian aurora. We discuss also the possibility of observing the predicted soft X-ray flux of hot Jupiters and show that despite high emission intensities they are unobservable with current facilities.

  16. Stelllar wind induced soft X-ray emission from close-in exoplanets

    NASA Astrophysics Data System (ADS)

    Kislyakova, Kristina; Fossati, Luca; Johnstone, Colin P.; Holmström, Mats; Zaitsev, Valery V.; Lammer, Helmut

    2016-04-01

    We estimate the X-ray emission from close-in exoplanets. We show that the Solar/Stellar Wind Charge Exchange Mechanism (SWCX) which produces soft X-ray radiation is very effective for hot Jupiters. In this mechanism, X-ray photons are produces by charge exchange between heavy ions in the solar wind and the atmospheric neutral particles. This mechanism is know to generate X-ray emission of comets in the Solar system. It has also been shown to operate in the heliosphere, in the terrestrial magnetosheath, and on Mars, Venus and Moon. Since the number of emitted photons is proportional to the solar wind mass flux, this mechanism is not effective for the Solar system giants. We present a simple estimate of the X-ray emission intensity that can be produced by close-in extrasolar Hot Jupiters due to charge exchange with the heavy ions of the stellar wind. Using the example of HD 209458b, we show that this mechanism alone can be responsible for an X-ray emission of ≈ 1022 erg s‑1, which is 106 times stronger than the emission from the Jovian aurora. We discuss the possibility to observe the predicted soft X-ray flux of hot Jupiters and show that despite high emission intensities they are unobservable with current facilities.

  17. Imaging of lateral spin valves with soft x-ray microscopy

    SciTech Connect

    Mosendz, O.; Mihajlovic, G.; Pearson, J. E.; Fischer, P.; Im, M.-Y.; Bader, S. D.; Hoffmann, A.

    2009-05-01

    We investigated Co/Cu lateral spin valves by means of high-resolution transmission soft x-ray microscopy with magnetic contrast that utilizes x-ray magnetic circular dichroism (XMCD). No magnetic XMCD contrast was observed at the Cu L{sub 3} absorption edge, which should directly image the spin accumulation in Cu. Although electrical transport measurements in a non-local geometry clearly detected the spin accumulation in Cu, which remained unchanged during illumination with circular polarized x-rays at the Co and Cu L{sub 3} absorption edges.

  18. A Sealed, UHV Compatible, Soft X-ray Detector Utilizing Gas Electron Multipliers

    SciTech Connect

    Schaknowski, N.A.; Smith, G.

    2009-10-25

    An advanced soft X-ray detector has been designed and fabricated for use in synchrotron experiments that utilize X-ray absorption spectroscopy in the study a wide range of materials properties. Fluorescence X-rays, in particular C{sub K} at 277eV, are converted in a low pressure gas medium, and charge multiplication occurs in two gas electron multipliers, fabricated in-house from glass reinforced laminate, to enable single photon counting. The detector satisfies a number of demanding characteristics often required in synchrotron environments, such as UHV compatibility compactness, long-term stability, and energy resolving capability.

  19. Anti-contamination device for cryogenic soft X-ray diffraction microscopy

    DOE PAGESBeta

    Huang, Xiaojing; Miao, Huijie; Nelson, Johanna; Turner, Joshua; Steinbrener, Jan; Shapiro, David; Kirz, Janos; Jacobsen, Chris

    2011-05-01

    Cryogenic microscopy allows one to view frozen hydrated biological and soft matter specimens with good structural preservation and a high degree of stability against radiation damage. We describe a liquid nitrogen-cooled anti-contamination device for cryogenic X-ray diffraction microscopy. The anti-contaminator greatly reduces the buildup of ice layers on the specimen due to condensation of residual water vapor in the experimental vacuum chamber. We show by coherent X-ray diffraction measurements that this leads to fivefold reduction of background scattering, which is important for far-field X-ray diffraction microscopy of biological specimens.

  20. Calibration of a high resolution grating soft x-ray spectrometer

    SciTech Connect

    Magee, E. W.; Dunn, J.; Brown, G. V.; Beiersdorfer, P.; Cone, K. V.; Park, J.; Porter, F. S.; Kilbourne, C. A.; Kelley, R. L.

    2010-10-15

    The calibration of the soft x-ray spectral response of a large radius of curvature, high resolution grating spectrometer (HRGS) with a back-illuminated charge-coupled device detector is reported. The instrument is cross-calibrated for the 10-50 A waveband at the Lawrence Livermore National Laboratory electron beam ion trap (EBIT) x-ray source with the EBIT calorimeter spectrometer. The HRGS instrument is designed for laser-produced plasma experiments and is important for making high dynamic range measurements of line intensities, line shapes, and x-ray sources.

  1. Calibration of a high resolution grating soft x-ray spectrometer.

    PubMed

    Magee, E W; Dunn, J; Brown, G V; Cone, K V; Park, J; Porter, F S; Kilbourne, C A; Kelley, R L; Beiersdorfer, P

    2010-10-01

    The calibration of the soft x-ray spectral response of a large radius of curvature, high resolution grating spectrometer (HRGS) with a back-illuminated charge-coupled device detector is reported. The instrument is cross-calibrated for the 10-50 Å waveband at the Lawrence Livermore National Laboratory electron beam ion trap (EBIT) x-ray source with the EBIT calorimeter spectrometer. The HRGS instrument is designed for laser-produced plasma experiments and is important for making high dynamic range measurements of line intensities, line shapes, and x-ray sources. PMID:21034013

  2. On-orbit calibration of soft X-ray detector on Chang'E-2 satellite

    NASA Astrophysics Data System (ADS)

    Xiao, Hong; Peng, Wen-Xi; Wang, Huan-Yu; Cui, Xing-Zhu; Guo, Dong-Ya

    2015-10-01

    The X-ray spectrometer is one of the satellite payloads on the Chang'E-2 satellite. The soft X-ray detector is one of the devices on the X-ray spectrometer, designed to detect the major rock-forming elements within the 0.5-10 keV range on the lunar surface. In this paper, energy linearity and energy resolution calibration is done using a weak 55Fe source. Temperature and time effects are found not to give a large error. The total uncertainty of calibration is estimated to be within 5% after correction. Supported by National Science Foundation of Ministry of Education

  3. Omega Dante Soft X-Ray Power Diagnostic Component Calibration at the National Synchrotron Light Source

    SciTech Connect

    Campbell, K; Weber, F; Dewald, E; Glenzer, S; Landen, O; Turner, R; Waide, P

    2004-04-15

    The Dante soft x-ray spectrometer installed on the Omega laser facility at the Laboratory for Laser Energetics, University of Rochester is a twelve-channel filter-edge defined x-ray power diagnostic. It is used to measure the absolute flux from direct drive, indirect drive (hohlraums) and other plasma sources. Calibration efforts using two beam lines, U3C (50eV-1keV) and X8A (1keV-6keV) at the National Synchrotron Light Source (NSLS) have been implemented to insure the accuracy of these measurements. We have calibrated vacuum x-ray diodes, mirrors and filters.

  4. Ultra soft X-ray Microbeam: optical analysis and intensity measurements

    NASA Astrophysics Data System (ADS)

    Emilio, M. Di Paolo; Palladino, L.; Del Grande, F.

    2016-06-01

    In this work, optical analysis and intensity measurements of the Ultra Soft x-ray microbeam (100 eV–1 keV) are presented. X-ray emission at 500 eV are generated from a plasma produced by focusing Nd-YAG laser beam on the Yttrium target. In particular, we will report the study of x-ray intensity and the measurement of focal spot dimension. Moreover, the software/hardware control of sample holder position and the alignment of biological sample to the microbeam will be described.

  5. The Soft X-ray research instrument at the Linac Coherent Light Source

    SciTech Connect

    Dakovski, Georgi L.; Heimann, Philip; Holmes, Michael; Krupin, Oleg; European XFEL, Hamburg; Minitti, Michael P.; Mitra, Ankush; Moeller, Stefan; Rowen, Michael; Schlotter, William F.; Turner, Joshua J.

    2015-04-02

    The Soft X-ray Research instrument provides intense ultrashort X-ray pulses in the energy range 280–2000 eV. A diverse set of experimental stations may be installed to investigate a broad range of scientific topics such as ultrafast chemistry, highly correlated materials, magnetism, surface science, and matter under extreme conditions. A brief description of the main instrument components will be given, followed by some selected scientific highlights.

  6. Emission Line Spectra in the Soft X-ray Region 20 - 75 Angstroms

    NASA Technical Reports Server (NTRS)

    Lepson, J. K.; Beiersdorfer, P.; Chen, H.; Behar, E.; Kahn, S. M.

    2002-01-01

    As part of a project to complete a comprehensive catalogue of astrophysically relevant emission lines in support of new-generation X-ray observatories using the Lawrence Livermore electron beam ion traps EBIT-I and EDIT-II, emission lines of argon and sulfur in the soft X-ray and extreme ultraviolet region were studied. Observations of Ar IX through Ar XVI and S VII through S XIV between 20 and 75 Angstrom are presented to illustrate our work.

  7. The Soft X-ray Research instrument at the Linac Coherent Light Source

    PubMed Central

    Dakovski, Georgi L.; Heimann, Philip; Holmes, Michael; Krupin, Oleg; Minitti, Michael P.; Mitra, Ankush; Moeller, Stefan; Rowen, Michael; Schlotter, William F.; Turner, Joshua J.

    2015-01-01

    The Soft X-ray Research instrument provides intense ultrashort X-ray pulses in the energy range 280–2000 eV. A diverse set of experimental stations may be installed to investigate a broad range of scientific topics such as ultrafast chemistry, highly correlated materials, magnetism, surface science, and matter under extreme conditions. A brief description of the main instrument components will be given, followed by some selected scientific highlights. PMID:25931059

  8. Emission Line Spectra in the Soft X-Ray Region 20-75 (Angstrom)

    SciTech Connect

    Lepson, J K; Beiersdorfer, P; Chen, H; Behar, E; Kahn, S M

    2002-06-18

    As part of a project to complete a comprehensive catalogue of astrophysically relevant emission lines in support of new-generation X-ray observatories using the Lawrence Livermore electron beam ion traps EBIT-I and EBIT-II, we studied emission lines of argon and sulfur in the soft X-ray and extreme ultraviolet region. Here we present observations of Ar IX through Ar XVI and S VII through S XIV between 20 and 75 {angstrom} to illustrate our work.

  9. Soft X-ray imaging techniques for calculating the Earth's dayside boundaries

    NASA Astrophysics Data System (ADS)

    Connor, Hyunju; Kuntz, Kip; Sibeck, David; Collier, Michael; Aryan, Homayon; Branduardi-Raymont, Graziella; Collado-Vega, Yaireska; Porter, Frederick; Purucker, Michael; Snowden, Steven; Raeder, Joachim; Thomas, Nicholas; Walsh, Brian

    2016-04-01

    Charged particles and neutral atoms exchange electrons in many space plasma venues. Soft X-rays are emitted when highly charged solar wind ions, such as C6+. O7+, and Fe13+, interact with Hydrogen and Helium atoms. Soft X-ray images can be a powerful technique to remotely probe the plasma and neutral density structures created when the solar wind interacts with planetary exospheres, such as those at the Earth, Moon, Mars, Venus, and comets. The recently selected ESA-China joint spacecraft mission, "Solar wind - Magnetosphere - Ionosphere Link Explorer (SMILE)" will have a soft X-ray imager on board and provide pictures of the Earth's dayside system after its launch in 2021. In preparation for this future mission, we simulate soft X-ray images of the Earth's dayside system, using the OpenGGCM global magnetosphere MHD model and the Hodges model of the Earth's exosphere. Then, we discuss techniques to determine the location of the Earth's dayside boundaries (bow shock and magnetopause) from the soft X-ray images.

  10. Laser Plasma Soft X-Ray Contact Microscopy of Polymer Composites

    NASA Astrophysics Data System (ADS)

    Azuma, Hirozumi; Takeichi, Akihiro; Noda, Shoji

    1994-08-01

    Microstructures of polymer composites are observed with a good contrast and with a submicron spatial resolution by contact soft X-ray microscopy with a laser plasma as a soft X-ray source. An iron target was irradiated by a YAG laser ( 2ω=532 nm, 0.4 J) at laser power density of 2.5×1012 W/cm2 and the emitted soft X-rays were filtered with a thin aluminum foil. For a 0.1-µ m-thick poly acrylonitrile-butadiene-styrene specimen, poly-butadiene or copolymer of butadiene spheres of about 500 nm diameter, which are selectively stained with osmium, is observed with soft X-rays in the wavelength region between 17 and 20 nm. For a 4-µ m-thick polyvinyl chloride film specimen formed by polymer powder compaction, peripheral areas of holes, grain boundaries, and areas probably degraded by HCl reduction are observed with soft X-rays in the wavelength region mainly around 2 nm.

  11. Soft X-ray synchrotron radiation investigations of actinidematerials systems utilizing X-ray emission spectroscopy and resonantinelastic X-ray scattering

    SciTech Connect

    Shuh, D.K.; Butorin, S.M.; Guo, J.-H.; Nordgren, J.

    2004-01-03

    Synchrotron radiation (SR) methods have been utilized with increasing frequency over the past several years to study topics in actinide science, ranging from those of a fundamental nature to those that address a specifically-targeted technical need. In particular, the emergence of microspectroscopic and fluorescence-based techniques have permitted investigations of actinide materials at sources of soft x-ray SR. Spectroscopic techniques with fluorescence-based detection are useful for actinide investigations since they are sensitive to small amounts of material and the information sampling depth may be varied. These characteristics also serve to simplify both sample preparation and safety considerations. Examples of investigations using these fluorescence techniques will be described along with their results, as well as the prospects for future investigations utilizing these methodologies.

  12. The soft x-ray instrument for materials studies at the linac coherent light source x-ray free-electron laser

    SciTech Connect

    Schlotter, W. F.; Turner, J. J.; Rowen, M.; Holmes, M.; Messerschmidt, M.; Moeller, S.; Krzywinski, J.; Lee, S.; Coffee, R.; Hays, G.; Heimann, P.; Krupin, O.; Soufli, R.; Fernandez-Perea, M.; Hau-Riege, S.; Kelez, N.; Beye, M.; Gerken, N.; Sorgenfrei, F.; Wurth, W.; and others

    2012-04-15

    The soft x-ray materials science instrument is the second operational beamline at the linac coherent light source x-ray free electron laser. The instrument operates with a photon energy range of 480-2000 eV and features a grating monochromator as well as bendable refocusing mirrors. A broad range of experimental stations may be installed to study diverse scientific topics such as: ultrafast chemistry, surface science, highly correlated electron systems, matter under extreme conditions, and laboratory astrophysics. Preliminary commissioning results are presented including the first soft x-ray single-shot energy spectrum from a free electron laser.

  13. X-ray dense cellular inclusions in the cells of the green alga Chlamydomonas reinhardtii as seen by soft-x-ray microscopy

    SciTech Connect

    Stead, A.D.; Ford, T.W.; Page, A.M.; Brown, J.T.; Meyer-Ilse, W.

    1997-04-01

    Soft x-rays, having a greater ability to penetrate biological material than electrons, have the potential for producing images of intact, living cells. In addition, by using the so-called {open_quotes}water window{close_quotes} area of the soft x-ray spectrum, a degree of natural contrast is introduced into the image due to differential absorption of the wavelengths by compounds with a high carbon content compared to those with a greater oxygen content. The variation in carbon concentration throughout a cell therefore generates an image which is dependent upon the carbon density within the specimen. Using soft x-ray contact microscopy the authors have previously examined the green alga Chlamydomonas reinhardtii, and the most prominent feature of the cells are the numerous x-ray absorbing spheres, But they were not seen by conventional transmission electron microscopy. Similar structures have also been reported by the Goettingen group using their cryo transmission x-ray microscope at BESSY. Despite the fact that these spheres appear to occupy up to 20% or more of the cell volume when seen by x-ray microscopy, they are not visible by transmission electron microscopy. Given the difficulties and criticisms associated with soft x-ray contact microscopy, the present study was aimed at confirming the existence of these cellular inclusions and learning more of their possible chemical composition.

  14. Note: Significant increase to the temporal resolution of 2D X-ray detectors using a novel beam chopper system

    SciTech Connect

    Küchemann, Stefan; Mahn, Carsten; Samwer, Konrad

    2014-01-15

    The investigation of short time dynamics using X-ray scattering techniques is commonly limited either by the read out frequency of the detector or by a low intensity. In this paper, we present a chopper system, which can increase the temporal resolution of 2D X-ray detectors by a factor of 13. This technique only applies to amorphous or polycrystalline samples due to their circular diffraction patterns. Using the chopper, we successfully increased the temporal resolution up to 5.1 ms during synchrotron experiments. For the construction, we provide a mathematical formalism, which, in principle, allows an even higher increase of the temporal resolution.

  15. Soft x-ray ionization induced fragmentation of glycine

    SciTech Connect

    Itälä, E.; Kooser, K.; Rachlew, E.; Huels, M. A.; Kukk, E.

    2014-06-21

    X-ray absorption commonly involves dissociative core ionization producing not only momentum correlated charged fragments but also low- and high-energy electrons capable of inducing damage in living tissue. This gives a natural motivation for studying the core ionization induced fragmentation processes in biologically important molecules such as amino acids. Here the fragmentation of amino acid glycine following carbon 1s core ionization has been studied. Using photoelectron-photoion-photoion coincidence technique, a detailed analysis on fragmentation of the sample molecule into pairs of momentum correlated cations has been carried out. The main characteristics of core ionization induced fragmentation of glycine were found to be the rupture of the C–C{sub α} bond and the presence of the CNH{sub 2}{sup +} fragment.

  16. Soft x-ray ionization induced fragmentation of glycine

    NASA Astrophysics Data System (ADS)

    Itälä, E.; Kooser, K.; Rachlew, E.; Huels, M. A.; Kukk, E.

    2014-06-01

    X-ray absorption commonly involves dissociative core ionization producing not only momentum correlated charged fragments but also low- and high-energy electrons capable of inducing damage in living tissue. This gives a natural motivation for studying the core ionization induced fragmentation processes in biologically important molecules such as amino acids. Here the fragmentation of amino acid glycine following carbon 1s core ionization has been studied. Using photoelectron-photoion-photoion coincidence technique, a detailed analysis on fragmentation of the sample molecule into pairs of momentum correlated cations has been carried out. The main characteristics of core ionization induced fragmentation of glycine were found to be the rupture of the C-Cα bond and the presence of the CNH_2^+ fragment.

  17. 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.

  18. Characteristics of x-ray emission from optically thin high-Z plasmas in the soft x-ray region

    NASA Astrophysics Data System (ADS)

    Ohashi, Hayato; Higashiguchi, Takeshi; Suzuki, Yuhei; Arai, Goki; Li, Bowen; Dunne, Padraig; O'Sullivan, Gerry; Sakaue, Hiroyuki A.; Kato, Daiji; Murakami, Izumi; Tamura, Naoki; Sudo, Shigeru; Koike, Fumihiro; Suzuki, Chihiro

    2015-07-01

    The characteristics of soft x-ray emission from optically thin high-Z plasmas of gold, lead and bismuth were investigated with the large helical device. Compared to optically thicker laser-produced plasmas, significantly different spectral structures were observed due to the difference in opacities and electron temperatures. Peak structures appearing in unresolved transition arrays were identified by calculations using atomic structure codes. The main contributors of discrete line emission in each case were Pd-, Ag-, and Rh-like ion stages. The present calculations point to the overestimation of contributions for 4p-4d transitions based on intensity estimates arising purely from gA distributions that predict strong emission from 4p-4d transitions. Understanding of such spectral emission is not only important for the completion of databases of high-Z highly ion charge states but also the development of promising high brightness sources for biological imaging applications.

  19. 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.

  20. ALP conversion and the soft X-ray excess in the outskirts of the Coma cluster

    SciTech Connect

    Kraljic, David; Rummel, Markus; Conlon, Joseph P. E-mail: Markus.Rummel@physics.ox.ac.uk

    2015-01-01

    It was recently found that the soft X-ray excess in the center of the Coma cluster can be fitted by conversion of axion-like-particles (ALPs) of a cosmic axion background (CAB) to photons. We extend this analysis to the outskirts of Coma, including regions up to 5 Mpc from the center of the cluster. We extract the excess soft X-ray flux from ROSAT All-Sky Survey data and compare it to the expected flux from ALP to photon conversion of a CAB. The soft X-ray excess both in the center and the outskirts of Coma can be simultaneously fitted by ALP to photon conversion of a CAB. Given the uncertainties of the cluster magnetic field in the outskirts we constrain the parameter space of the CAB. In particular, an upper limit on the CAB mean energy and a range of allowed ALP-photon couplings are derived.

  1. Wide field-of-view soft X-ray imaging for solar wind-magnetosphere interactions

    NASA Astrophysics Data System (ADS)

    Walsh, B. M.; Collier, M. R.; Kuntz, K. D.; Porter, F. S.; Sibeck, D. G.; Snowden, S. L.; Carter, J. A.; Collado-Vega, Y.; Connor, H. K.; Cravens, T. E.; Read, A. M.; Sembay, S.; Thomas, N. E.

    2016-04-01

    Soft X-ray imagers can be used to study the mesoscale and macroscale density structures that occur whenever and wherever the solar wind encounters neutral atoms at comets, the Moon, and both magnetized and unmagnetized planets. Charge exchange between high charge state solar wind ions and exospheric neutrals results in the isotropic emission of soft X-ray photons with energies from 0.1 to 2.0 keV. At Earth, this process occurs primarily within the magnetosheath and cusps. Through providing a global view, wide field-of-view imaging can determine the significance of the various proposed solar wind-magnetosphere interaction mechanisms by evaluating their global extent and occurrence patterns. A summary of wide field-of-view (several to tens of degrees) soft X-ray imaging is provided including slumped micropore microchannel reflectors, simulated images, and recent flight results.

  2. Initial Operation of the NSTX Fast Tangential Soft X-Ray Camera

    SciTech Connect

    B.C. Stratton; R. Feder; S. von Goeler; G.F. Renda; J.L. Lowrance; V.J. Mastrocola

    2004-05-11

    Fast, two-dimensional, soft x-ray imaging is a powerful technique for the study of MHD instabilities in tokamak plasmas. We have constructed an ultra-fast frame rate soft x-ray camera for the National Spherical Torus Experiment. It is based on a recently developed 64 x 64 pixel CCD camera capable of capturing 300 frames at up to 500,000 frames per second. A pinhole aperture images the plasma soft x-ray emission (0.2-10 keV) onto a P47 scintillator deposited on a fiber-optic faceplate; the scintillator visible light output is detected and amplified by a demagnifying image intensifier and lens-coupled to the CCD chip. A selection of beryllium foils provides discrimination of low-energy emission. The system is installed on NSTX with a wide-angle tangential view of the plasma. Initial plasma data and an assessment of the system performance are presented.

  3. Continuous high-repetition-rate operation of collisional soft-x-ray lasers with solid targets.

    PubMed

    Weith, A; Larotonda, M A; Wang, Y; Luther, B M; Alessi, D; Marconi, M C; Rocca, J J; Dunn, J

    2006-07-01

    We have generated a laser average output power of 2 microW at a wavelength of 13.9 nm by operating a tabletop laser-pumped Ni-like Ag laser at a 5 Hz repetition rate, using a solid helicoidal target that is continuously rotated and advanced to renew the target surface between shots. More than 2 x 10(4) soft-x-ray laser shots were obtained by using a single target. Similar results were obtained at 13.2 nm in Ni-like Cd with a Cd-coated target. This scheme will allow uninterrupted operation of laser-pumped tabletop collisional soft-x-ray lasers at a repetition rate of 10 Hz for a period of hours, enabling the generation of continuous high average soft-x-ray powers for applications. PMID:16770410

  4. In situ/operando soft x-ray spectroscopy characterization of ion solvation and catalysis

    NASA Astrophysics Data System (ADS)

    Liu, Yi-Sheng; Guo, Jinghua

    Many important systems especially in energy-related regime are based on the complexity of material architecture, chemistry and interactions among constituents within. To understand and thus ultimately control the varying applications calls for in-situ/operando characterization tools. We will present the recent development of the in-situ/operando soft X-ray spectroscopic in the studies of catalytic and alkali ion solvation under bias condition, and reveal how to overcome the challenge that soft X-rays cannot easily peek into the high-pressure catalytic cells or liquid electrochemical cells. Also the different feasible detection approaches can provide surface and bulk sensitivity experimentally from those in-situ cells. The unique design of in-situ/operando soft X-ray spectroscopy instrumentation and fabrication principle with examples in Ca, Na, Mg based solutions at ambient pressure/temperature and high temperature (~250°C) gas catalysis will be shown.

  5. Overview of the program on soft x-ray lasers and their applications at Princeton

    SciTech Connect

    Suckewer, S.; Ilcisin, K. . Plasma Physics Lab. Princeton Univ., NJ . Dept. of Mechanical and Aerospace Engineering)

    1991-05-01

    In the last several years, rapid progress in the development of soft x-ray lasers (SXL) has been observed at a number of laboratories worldwide. Although SXLs are very young'' devices they have already been used for microscopy and holography, and new ideas emerging for broader application of SXLs to microscopy, holography and lithography. This paper describes the work at Princeton University on the development of a soft x-ray imaging transmission microscopy using a SXL as a radiation source and work on the development of a novel soft x-ray reflection microscope and its application to biological cell studies and lithography. Progress in the development of a photopumped VUV laser (60 nm), and programs for the development of a small scale SXL and for the application of a powerful subpicosecond KrF laser system are also discussed. 35 refs., 9 figs., 1 tab.

  6. The coolest DA white dwarfs detected at soft X-ray wavelengths

    NASA Technical Reports Server (NTRS)

    Kidder, K. M.; Holberg, J. B.; Barstow, M. A.; Tweedy, R. W.; Wesemael, F.

    1992-01-01

    New soft X-ray/EUV photometric observations of the DA white dwarfs KPD 0631 + 1043 = WD 0631 + 107 and PG 1113 + 413 = WD 1113 + 413 are analyzed. Previously reported soft X-ray detections of three other DAs and the failure to detect a fourth DA in deep Exosat observations are investigated. New ground-based spectra are presented for all of the objects, with IUE Ly-alpha spectra for some. These data are used to constrain the effective temperatures and surface gravities. The improved estimates of these parameters are employed to refer a photospheric He abundance for the hotter objects and to elucidate an effective observational low-temperature threshold for the detection of pure hydrogen DA white dwarfs at soft X-ray wavelengths.

  7. Critical Reexamination of Resonant Soft X-Ray Bragg Forbidden Reflections in Magnetite

    SciTech Connect

    Wilkins, S.B.; Di Matteo, S.; Beale, T.A.W.; Joly, Y.; Mazzoli, C.; Hatton, P.D.; Bencok, P.; Yakhou, F.; Brabers, V.A.M.

    2009-05-01

    Magnetite, Fe{sub 3}O{sub 4}, displays a highly complex low-temperature crystal structure that may be charge and orbitally ordered. Many of the recent experimental claims of such ordering rely on resonant soft x-ray diffraction at the oxygen K and iron L edges. We have reexamined this system and undertaken soft x-ray diffraction experiments on a high-quality single crystal. Contrary to previous claims in the literature, we show that the intensity observed at the Bragg forbidden (001/2){sub c} reflection can be explained purely in terms of the low-temperature structural displacements around the resonant atoms. This does not necessarily mean that magnetite is not charge or orbitally ordered but rather that the present sensitivity of resonant soft x-ray experiments does not allow conclusive demonstration of such ordering.

  8. Examination of Cadence of Solar Soft X-ray Flux on the Ionosphere and Thermosphere

    NASA Astrophysics Data System (ADS)

    Smith, D. C.; Talaat, E. R.; Yee, J.; Woods, T.; Roble, R. G.; Crowley, G.

    2006-12-01

    The solar soft x-ray flux is crucial to modeling the thermosphere and ionosphere accurately. However, measurements of soft x-ray spectrum (0-10~nm) have been few and far between. As a result, the time variation of the spectrum has been tied to daily indices, such as F10.7 or E10.7. While this is adequate for long term studies such as seasonal, annual, or solar cycle variations, studies that address short-term effects such as geomagnetic disturbances or solar flares require a higher cadence input for a more proper driver of physics. With recent solar soft x-ray and EUV data available from the Solar Extreme ultraviolet Experiment (SEE) onboard the Thermosphere Ionosphere Mesosphere Energetics Dynamics (TIMED) satellite, a complete spectrum is available, but only once every orbit (~97 minutes). In this paper, we examine the effects of varying the cadence in which high energy solar irradiance is input into the global thermosphere-ionosphere- electrodynamics general circulation model (TIE-GCM). Specifically, we compare once a day, once an orbit, and every minute cadence and the resulting ionospheric and thermospheric response. We use the observed solar spectrum from SEE/TIMED and combine the measurements from SEE with the 1-min Geostationary Oribiting Earth Satellite (GOES) Space Environment Monitor (SEM) hard x-ray flux to produce high cadence solar soft x-ray flux.

  9. [Experimental investigation of laser plasma soft X-ray source with gas target].

    PubMed

    Ni, Qi-liang; Gong, Yan; Lin, Jing-quan; Chen, Bo; Cao, Jian-lin

    2003-02-01

    This paper describes a debris-free laser plasma soft X-ray source with a gas target, which has high operating frequency and can produce strong soft X-ray radiation. The valve of this light source is drived by a piezoelectrical ceramic whose operating frequency is up to 400 Hz. In comparison with laser plasma soft X-ray sources using metal target, the light source is debris-free. And it has higher operating frequency than gas target soft X-ray sources whose nozzle is controlled by a solenoid valve. A channel electron multiplier (CEM) operating in analog mode is used to detect the soft X-ray generated by the laser plasma source, and the CEM's output is fed to to a charge-sensitive preamplifier for further amplification purpose. Output charges from the CEM are proportional to the amplitude of the preamplifier's output voltage. Spectra of CO2, Xe and Kr at 8-14 nm wavelength which can be used for soft X-ray projection lithography are measured. The spectrum for CO2 consists of separate spectral lines originate mainly from the transitions in Li-like and Be-like ions. The Xe spectrum originating mainly from 4d-5f, 4d-4f, 4d-6p and 4d-5p transitions in multiply charged xenon ions. The spectrum for Kr consists of separate spectral lines and continuous broad spectra originating mainly from the transitions in Cu-, Ni-, Co- and Fe-like ions. PMID:12939982

  10. Soft x-ray emission spectra of lithium fluoride excited by synchrotron radiation

    SciTech Connect

    Tsang, K.L.; Zhang, C.H.; Callcott, T.A.; Arakawa, E.T.; Ederer, D.L.

    1986-01-01

    A core excited Li atom is perhaps the simplest cation defect that can be introduced into LiF. It frequently binds an electron in an electronic state, whose properties dominate both the soft x-ray absorption and soft x-ray emission properties of LiF. This phenomena was examined using a new, very high efficiency, emission spectrometer. Exciton and valence band peaks were observed which decay with time and are replaced by a metallic Li peak at 54 eV.

  11. High Precision Mechanical Components for Soft X-ray Beamline: Engineering Goal and Testing Results

    SciTech Connect

    Kaznacheyev, K. V.; Karunakaran, Ch.; Sitnikov, A.; Loken, D.; Warwick, T.; Nagy, M.; Hitchcock, A. P.

    2007-01-19

    As the emittance of SR rings approaches the diffraction limit for soft x-rays, one requires not only excellence in design and performance of the optical elements, but also precision and performance of mechanical components, such as mirror manipulators, monochromator scanners and exit slits. We will present simple but efficient solutions for the mechanical systems of this type, commonly encountered in soft x-ray beamlines. These solutions have been implemented and their performance evaluated with test results from the spectromicroscopy beamline at the Canadian Light Source.

  12. High Precision Mechanical Components for Soft X-ray Beamline: Engineering Goal and Testing Results

    NASA Astrophysics Data System (ADS)

    Kaznacheyev, K. V.; Karunakaran, Ch.; Sitnikov, A.; Loken, D.; Warwick, T.; Nagy, M.; Hitchcock, A. P.

    2007-01-01

    As the emittance of SR rings approaches the diffraction limit for soft x-rays, one requires not only excellence in design and performance of the optical elements, but also precision and performance of mechanical components, such as mirror manipulators, monochromator scanners and exit slits. We will present simple but efficient solutions for the mechanical systems of this type, commonly encountered in soft x-ray beamlines. These solutions have been implemented and their performance evaluated with test results from the spectromicroscopy beamline at the Canadian Light Source.

  13. Multilayer films with sharp, stable interfaces for use in EUV and soft X-ray application

    DOEpatents

    Barbee, Jr., Troy W.; Bajt, Sasa

    2002-01-01

    The reflectivity and thermal stability of Mo/Si (molybdenum/silicon) multilayer films, used in soft x-ray and extreme ultraviolet region, is enhanced by deposition of a thin layer of boron carbide (e.g., B.sub.4 C) between alternating layers of Mo and Si. The invention is useful for reflective coatings for soft X-ray and extreme ultraviolet optics, multilayer for masks, coatings for other wavelengths and multilayers for masks that are more thermally stable than pure Mo/Si multilayers

  14. Soft X-rays, winds, and the cataclysmic variable boundary-layer problem

    NASA Technical Reports Server (NTRS)

    Kallman, T. R.; Jensen, K. A.

    1985-01-01

    Models are presented for the effects of a stellar wind on the UV and soft X-ray spectra of cataclysmic variables (CVs). It is shown that P Cygni absorption lines observed from many CVs are consistent with the existence of a strong wind, and that such a wind can also account for the soft X-ray upper limits if the wind mass loss rate is about 10 to the -8th solar masses per yr. The implications of such a wind for the CV momentum and energy budget are discussed.

  15. Intracellular nanoparticles mass quantification by near-edge absorption soft X-ray nanotomography

    NASA Astrophysics Data System (ADS)

    Conesa, Jose Javier; Otón, Joaquín; Chiappi, Michele; Carazo, Jose María; Pereiro, Eva; Chichón, Francisco Javier; Carrascosa, José L.

    2016-03-01

    We used soft X-ray three-dimensional imaging to quantify the mass of superparamagnetic iron oxide nanoparticles (SPION) within whole cells, by exploiting the iron oxide differential absorption contrast. Near-edge absorption soft X-ray nanotomography (NEASXT) combines whole-cell 3D structure determination at 50 nm resolution, with 3D elemental mapping and high throughput. We detected three-dimensional distribution of SPIONs within cells with 0.3 g/cm3 sensitivity, sufficient for detecting the density corresponding to a single nanoparticle.

  16. Intracellular nanoparticles mass quantification by near-edge absorption soft X-ray nanotomography

    PubMed Central

    Conesa, Jose Javier; Otón, Joaquín; Chiappi, Michele; Carazo, Jose María; Pereiro, Eva; Chichón, Francisco Javier; Carrascosa, José L.

    2016-01-01

    We used soft X-ray three-dimensional imaging to quantify the mass of superparamagnetic iron oxide nanoparticles (SPION) within whole cells, by exploiting the iron oxide differential absorption contrast. Near-edge absorption soft X-ray nanotomography (NEASXT) combines whole-cell 3D structure determination at 50 nm resolution, with 3D elemental mapping and high throughput. We detected three-dimensional distribution of SPIONs within cells with 0.3 g/cm3 sensitivity, sufficient for detecting the density corresponding to a single nanoparticle. PMID:26960695

  17. Experimental demonstration of a soft x-ray self-seeded free-electron laser

    DOE PAGESBeta

    Ratner, D.; Abela, R.; Amann, J.; Behrens, C.; Bohler, D.; Bouchard, G.; Bostedt, C.; Boyes, M.; Chow, K.; Cocco, D.; et al

    2015-02-06

    The Linac Coherent Light Source has added self-seeding capability to the soft x-ray range using a grating monochromator system. We report demonstration of soft x-ray self-seeding with a measured resolving power of 2000-5000, wavelength stability of 10-4, and an increase in peak brightness by a factor of 2-5 across the photon energy range of 500-1000 eV. By avoiding the need for a monochromator at the experimental station, the self-seeded beam can deliver as much as 50 fold higher brightness to users.

  18. Experimental demonstration of a soft x-ray self-seeded free-electron laser

    SciTech Connect

    Ratner, D.; Abela, R.; Amann, J.; Behrens, C.; Bohler, D.; Bouchard, G.; Bostedt, C.; Boyes, M.; Chow, K.; Cocco, D.; Decker, F. J.; Ding, Y.; Eckman, C.; Emma, P.; Fairley, D.; Feng, Y.; Field, C.; Flechsig, U.; Gassner, G.; Hastings, J.; Heimann, P.; Huang, Z.; Kelez, N.; Krzywinski, J.; Loos, H.; Lutman, A.; Marinelli, A.; Marcus, G.; Maxwell, T.; Moeller, S.; Morton, D.; Nuhn, H. D.; Rodes, N.; Schlotter, W.; Serkez, S.; Stevens, T.; Turner, J.; Walz, D.; Welch, J.; Wu, J.

    2015-02-06

    The Linac Coherent Light Source has added self-seeding capability to the soft x-ray range using a grating monochromator system. We report demonstration of soft x-ray self-seeding with a measured resolving power of 2000-5000, wavelength stability of 10-4, and an increase in peak brightness by a factor of 2-5 across the photon energy range of 500-1000 eV. By avoiding the need for a monochromator at the experimental station, the self-seeded beam can deliver as much as 50 fold higher brightness to users.

  19. Optimization of reflectivity of periodic and quasiperiodic multilayer films at soft X-ray wavelengths

    NASA Astrophysics Data System (ADS)

    Gu, E.; Marr, G. V.; Player, M. A.

    1990-06-01

    The reflectivity of multilayer films consisting of alternating layers of high and low refractive index is investigated. It is found that the thickness of periods affects the optimized reflectivity, and that a quasi-periodic structure with fixed thickness of periods but changing thicknesses of the layers can form two reflecting peaks at different wavelength positions. The result can be used to increase the bandwidth and to change the shape of reflectivity curves in the soft X-ray region. Since nonabsorbing material does not exist in the soft X-ray region, the thickness of each layer should be optimized separately in order to obtain maximum reflectivity at a single wavelength.

  20. Characteristics of the soft X-ray emission from laser-produced highly charged platinum plasmas

    NASA Astrophysics Data System (ADS)

    Hara, Hiroyuki; Arai, Goki; Kondo, Yoshiki; Dinh, Thanh-Hung; Dunne, Padraig; O’Sullivan, Gerry; Ejima, Takeo; Hatano, Tadashi; Jiang, Weihua; Nishikino, Masaharu; Sasaki, Akira; Sunahara, Atsushi; Higashiguchi, Takeshi

    2016-06-01

    We characterized the spectral structure of the soft X-ray emission and determined the plasma parameters in laser-produced highly charged platinum plasmas. The spectral structure observed originated from Pt21+ to Pt34+ ions, emissions from which overlapped to produce a high output flux in the carbon-window soft X-ray spectral region. Using dual laser pulse irradiation, we observed the maximum output flux, which was 20% larger than that obtained under single-laser irradiation, and the evolution of a strongly absorbed spectral structure, which was attributed to the effects of both opacity and long-scale length of the expanding pre-plasma.

  1. Intracellular nanoparticles mass quantification by near-edge absorption soft X-ray nanotomography.

    PubMed

    Conesa, Jose Javier; Otón, Joaquín; Chiappi, Michele; Carazo, Jose María; Pereiro, Eva; Chichón, Francisco Javier; Carrascosa, José L

    2016-01-01

    We used soft X-ray three-dimensional imaging to quantify the mass of superparamagnetic iron oxide nanoparticles (SPION) within whole cells, by exploiting the iron oxide differential absorption contrast. Near-edge absorption soft X-ray nanotomography (NEASXT) combines whole-cell 3D structure determination at 50 nm resolution, with 3D elemental mapping and high throughput. We detected three-dimensional distribution of SPIONs within cells with 0.3 g/cm(3) sensitivity, sufficient for detecting the density corresponding to a single nanoparticle. PMID:26960695

  2. Experimental demonstration of a soft x-ray self-seeded free-electron laser.

    PubMed

    Ratner, D; Abela, R; Amann, J; Behrens, C; Bohler, D; Bouchard, G; Bostedt, C; Boyes, M; Chow, K; Cocco, D; Decker, F J; Ding, Y; Eckman, C; Emma, P; Fairley, D; Feng, Y; Field, C; Flechsig, U; Gassner, G; Hastings, J; Heimann, P; Huang, Z; Kelez, N; Krzywinski, J; Loos, H; Lutman, A; Marinelli, A; Marcus, G; Maxwell, T; Montanez, P; Moeller, S; Morton, D; Nuhn, H D; Rodes, N; Schlotter, W; Serkez, S; Stevens, T; Turner, J; Walz, D; Welch, J; Wu, J

    2015-02-01

    The Linac Coherent Light Source has added a self-seeding capability to the soft x-ray range using a grating monochromator system. We report the demonstration of soft x-ray self-seeding with a measured resolving power of 2000-5000, wavelength stability of 10(-4), and an increase in peak brightness by a factor of 2-5 across the photon energy range of 500-1000 eV. By avoiding the need for a monochromator at the experimental station, the self-seeded beam can deliver as much as 50-fold higher brightness to users. PMID:25699448

  3. High-average-power 100-Hz repetition rate table-top soft x-ray lasers

    NASA Astrophysics Data System (ADS)

    Rocca, Jorge J.; Reagan, Brendan A.; Wernsing, Keith; Wang, Yong; Yin, Liang; Wang, Shoujun; Berrill, Mark; Woolston, Mark R.; Curtis, Alden H.; Furch, Federico J. A.; Shlyaptsev, Vyacheslav N.; Luther, Brad M.; Patel, Dinesh; Marconi, Mario C.; Menoni, Carmen S.

    2013-09-01

    The table-top generation of high average power coherent soft x-ray radiation in a compact set up is of high interest for numerous applications. We have demonstrated the generation of bright soft x-ray laser pulses at 100 Hz repetition rate with record-high average power from compact plasma amplifiers excited by an ultrafast diode-pumped solid state laser. Results of compact λ=18.9nm Ni-like Mo and λ=13.9nm Ni-like Ag lasers operating at 100 Hz repetition rate are discussed.

  4. Wide-Field MAXI - Wide-Field Soft X-ray Transient Monitor on the ISS

    NASA Astrophysics Data System (ADS)

    Kawai, Nobuyuki

    WF-MAXI is a mission to detect and localize X-ray transients including GRBs and XRFs, X-ray binaries, and hopefully tidal disruption events and supernova shockbreakouts. We are designing WF-MAXI to be ready for the initial operational phase of the next generation GW telescopes: Adv-LIGO, VIRGO and KAGRA, which are expected to be operational in 2-4 years. It will be sensitive to soft extended emission of short GRBs. It will also succeed the current MAXI mission, which is providing alerts for outbursts of X-ray sources to the community. We chose to use flight-proven or qualified technologies developed for MAXI, ASTRO-H, and TSUBAME for a fast development of the mission. The main instrument is Soft X-ray Large-sky Cameras (SLC), pairs of criss-cross coded aperture cameras using CCD as one-dimensional fast-readout detectors covering 20% of the sky in the 0.7-12 keV band. The Hard X-ray Monitor share the same field as SLC in the hard X-ray band. We are proposing this mission for the ISS/JEM AO in this year aiming to start operations in 2018.

  5. Nanostructured diffractive optical devices for soft X-ray microscopes

    NASA Astrophysics Data System (ADS)

    Hambach, D.; Peuker, M.; Schneider, G.

    2001-07-01

    The new transmission X-ray microscope (TXM) installed at the BESSY II electron storage ring uses an off-axis transmission zone plate (OTZ) as diffractive and focusing element of the condenser-monochromator setup. A high resolution micro-zone plate (MZP) forms a magnified image on a CCD-detector. Both, the OTZ with an active area of up to 24 mm2 and the MZP with zone widths as small as 25 nm are generated by a process including electron beam lithography (EBL), dry etching and subsequent electroplating of nickel on top of silicon membrane substrates with about 100- 150 nm thickness. The combination of a larger zone width and the usage of nickel zone structures allows to increase the diffraction efficiency of the condenser element at least by a factor of 3 compared to the earlier used KZP7 condenser zone plate in the TXM at BESSY I. Groove diffraction efficiencies of 21.6% and 14.7% were measured for MZP objectives with 40 and 25 nm outermost zone width, respectively.

  6. The ISM From the Soft X-ray Background Perspective

    NASA Technical Reports Server (NTRS)

    Snowden, S. L.

    2003-01-01

    In the past few years progress in understanding the local and Galactic ISM in terms of the diffuse X-ray background has been as much about what hasn't been seen as it has been about detections. High resolution spectra of the local SXRB have been observed, but are inconsistent with current thermal emission models. An excess over the extrapolation of the high-energy (most clearly visible at E greater than 1.5 keV) extragalactic power law down to 3/4 keV has been observed but only at the level consistent with cosmological models, implying the absence of at least a bright hot Galactic halo. A very recent FUSE result indicates that O VI emission from the Local Hot Bubble is insignificant, if it exists at all, a result which is also inconsistent with current thermal emission models. A short review of the current status of our (well, at least my) understanding of the Galactic SXRB and ISM is presented here.

  7. A study of X-ray emission from galactic and extragalactic sources with emphasis on soft and ultra-soft wavelengths

    NASA Technical Reports Server (NTRS)

    Bowyer, C. S.; Lampton, M.; Cruddace, R. G.; Paresce, F.

    1974-01-01

    A Black Brant VC rocket was used to scan the Coma and Virgo clusters in order to measure structure in the X-ray sources. The rocket also made measurements of soft X-ray spectra, soft X-ray background flux during a 50 deg scan of the sky, soft X-rays from De Voucoulers 50, set limits to the energy dependence of soft X-ray background spectra, and the flux of solar 584 A radiation resonantly scattered by interstellar He flowing through the solar system.

  8. First measurement of the ASTRO-H soft x-ray telescope performance

    NASA Astrophysics Data System (ADS)

    Okajima, Takashi; Serlemitsos, Peter J.; Soong, Yang; Hahne, Devin J.

    2012-09-01

    ASTRO-H is a Japanese X-ray astrophysics satellite under the development led by Japan and US. It will have two Soft X-ray Telescopes (SXTs), among other instruments, that are being developed by NASA's Goddard Space Flight Center. One is for an X-ray micro-calorimeter instrument and the other for an X-ray CCD camera, both covering the X-ray energy band below 15 keV. The SXT Engineering Model (EM) quadrant was successfully completed and has shown big improvements in the X-ray performance from Suzaku owing to number of changes made. The EM was tested at the Goddard 100-m X-ray beamline (diverging beam) and the ISAS/JAXA beamline (pencil beam scan). The angular resolution was found to be 1.1 arcmin at Goddard, while 1.27 arcmin at ISAS, and the effective area was 157 and 122 cm2 at 1 and 6 keV, respectively. The discrepancy in the angular resolution can be explained by the difference of the measurement method, i.e. the diverging beam vs. the pencil beam scan. The development of the first Flight Model (FM) is underway. The first three quadrants are completed so far and show about 1 arcmin (HPD) angular resolution. We expect that the first FM SXT will have about 1 arcmin resolution, which will be completed in September, 2012.

  9. Development of the ASTRO-H Soft X-ray Telescope (SXT): Engineering Model Performance

    NASA Technical Reports Server (NTRS)

    Okajima, Takashi; Serlemitsos, P. J.; Soong, Y.

    2011-01-01

    The X-ray astronomy satellite ASTRO-H, being developed under the collaboration among JAXA, NASA's GSFC and ESA, will have two Soft X-ray Telescopes (SXTs), among other instuments onboard, with a sensitive energy band below 12 keV. One is for an X-ray micorocalorimeter detector and the other for a X-ray CCD detector. The SXT uses a conically approximated Wolter I grazing incidence optic implemented by thin aluminum foil substrates with thickness of 0.152, 0.229, and 0.305 mm. It is similar to the Suzaku XRT, but with larger diameter (45 cm) and longer focal length (5.6 m). Goal of the angular resolution and effective area are 1 arcmin and 390 cm$A2$ at 6 keV, respectively. We made serveral improvements from Suzaku to ASTRO-H, such as thicker substrates, more forming mandrels, thinner epoxy layer for replication, stiffer housings, precise alignment bars, etc. With all these changes, we have fabricated the engineering test unit of the SXT. In this paper, we will discuss all the changes made, their effects, and report X-ray performance of the SXT test unit. An angular resolution of the test unit was measured at new Goddard X-ray calibration facility (100 m X-ray beamline) and was found to be 1.1 arcmin. We will also discuss further improvements toward the flight unit to be delivered to JAXA in 2012.

  10. Soft X-ray observations of pre-main sequence stars in the chamaeleon dark cloud

    NASA Technical Reports Server (NTRS)

    Feigelson, Eric D.; Kriss, Gerard A.

    1987-01-01

    Einstein IPC observations of the nearby Chamaeleon I star forming cloud show 22 well-resolved soft X-ray sources in a 1x2 deg region. Twelve are associated with H-alpha emission line pre-main sequence (PMS) stars, and four with optically selected PMS stars. Several X-ray sources have two or more PMS stars in their error circles. Optical spectra were obtained at CTIO of possible stellar counterparts of the remaining X-ray sources. They reveal 5 probable new cloud members, K7-MO stars with weak or absent emission lines. These naked X-ray selected PMS stars are similar to those found in the Taurus-Auriga cloud. The spatial distributions and H-R diagrams of the X-ray and optically selected PMS stars in the cloud are very similar. Luminosity functions indicate the Chamaeleon stars are on average approximately 5 times more X-ray luminous than Pleiad dwarfs. A significant correlation between L sub x and optical magnitude suggests this trend may continue within the PMS phase of stellar evolution. The relation of increasing X-ray luminosity with decreasing stellar ages is thus extended to stellar ages as young as 1 million years.

  11. The photoelectric effect from CsI by polarized soft X-rays

    NASA Technical Reports Server (NTRS)

    Shaw, Ping S.; Church, Eric D.; Hanany, Shaul; Liu, Yee; Fleischman, Judith; Kaaret, Philip; Novick, Robert; Manzo, Giuseppe

    1991-01-01

    Studies of the polarization dependence of the photoelectric effect produced by soft X-rays from CsI indicate that the geometrical effects in these experiments can often mimic the polarization signature. This paper presents a detailed calculation of these geometrical effects that are produced when the X-ray beam is not precisely aligned on a rotatable plane photocathode. The experimentally observed geometrical effects were used to precisely determine the realignment of the incident beam of polarized X-rays on a rotatable photocathode. The results allow determinations of the true polarization dependence of the photoemission from CsI. It is shown that the photoelectric effect in CsI depends on the polarization state of the X-rays.

  12. Writable graphene: Breaking sp2 bonds with soft X-rays

    SciTech Connect

    Zhou, S.; Girit, C.; Scholl, A.; Jozwiak, C.; Siegel, D.; Yu, P.; Robinson, J.; Wang, F.; Zettl, A.; Lanzara, A.

    2010-06-09

    We study the stability of various kinds of graphene samples under soft x-ray irradiation. Our results show that in single-layer exfoliated graphene (a closer analog to two-dimensional material), the in-plane carbon-carbon bonds are unstable under x-ray irradiation, resulting in nanocrystalline structures. As the interaction along the third dimension increases by increasing the number of graphene layers or through the interaction with the substrate (epitaxial graphene), the effect of x-ray irradiation decreases and eventually becomes negligible for graphite and epitaxial graphene. Our results demonstrate the importance of the interaction along the third dimension in stabilizing the long range in-plane carbon-carbon bonding, and suggest the possibility of using x-ray to pattern graphene nanostructures in exfoliated graphene.

  13. Contributions of late-type dwarf stars to the soft X-ray diffuse background

    SciTech Connect

    Schmitt, J.H.M.M.; Snowden, S.L. Wisconsin Univ., Madison )

    1990-09-01

    Comprehensive calculations of the contribution of late-type dwarf stars to the soft X-ray diffuse background are presented. The mean X-ray luminosity as derived from optically and X-ray selected samples is examined, using the Bahcall-Soneira Galaxy model to describe the spatial distribution of stars and recent results on the X-ray spectra. The model calculations are compared with the Wisconsin sky maps in the C, M1, M2, I and J bands to assess the uncertainties of the calculations. Contributions of up to 10 percent to the M2 and I band background at high Galactic latitudes are found, while at low Galactic latitudes late-type stars contribute up to 40 percent of the background. However, a Galactic ridge as well as a relatively isotropic component still remains unexplained, even with the added contribution of the extrapolated high-energy power law. 41 refs.

  14. Contributions of late-type dwarf stars to the soft X-ray diffuse background

    NASA Technical Reports Server (NTRS)

    Schmitt, J. H. M. M.; Snowden, S. L.

    1990-01-01

    Comprehensive calculations of the contribution of late-type dwarf stars to the soft X-ray diffuse background are presented. The mean X-ray luminosity as derived from optically and X-ray selected samples is examined, using the Bahcall-Soneira Galaxy model to describe the spatial distribution of stars and recent results on the X-ray spectra. The model calculations are compared with the Wisconsin sky maps in the C, M1, M2, I and J bands to assess the uncertainties of the calculations. Contributions of up to 10 percent to the M2 and I band background at high Galactic latitudes are found, while at low Galactic latitudes late-type stars contribute up to 40 percent of the background. However, a Galactic ridge as well as a relatively isotropic component still remains unexplained, even with the added contribution of the extrapolated high-energy power law.

  15. 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.

  16. 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.

  17. Single-shot calibration of soft x-ray mirrors using a sinusoidal transmission grating.

    PubMed

    Shpilman, Z; Ehrlich, Y; Maman, S; Levy, I; Shussman, T; Oren, G; Zakosky Nueberger, I; Hurvitz, G

    2014-11-01

    Calibration of soft x-ray diagnostics is a challenge due to the lack of laboratory-size calibrated sources. An in situ calibration method for newly developed x-ray mirrors, is presented. The x-ray source is produced by laser-matter interaction, and twin transmission gratings which create two identical dispersion lines. The gratings have a sinusoidal transmission function, which produces a highly precise high-orders free spectrum. An x-ray mirror interacts with one of the dispersion lines, and the mirror efficiency curve as a function of wavelength is extracted. Mirror efficiency shows good agreement with the literature, and evidence of water layer may justify the need of in situ calibration. PMID:25430374

  18. Single-shot calibration of soft x-ray mirrors using a sinusoidal transmission grating

    NASA Astrophysics Data System (ADS)

    Shpilman, Z.; Ehrlich, Y.; Maman, S.; Levy, I.; Shussman, T.; Oren, G.; Zakosky Nueberger, I.; Hurvitz, G.

    2014-11-01

    Calibration of soft x-ray diagnostics is a challenge due to the lack of laboratory-size calibrated sources. An in situ calibration method for newly developed x-ray mirrors, is presented. The x-ray source is produced by laser-matter interaction, and twin transmission gratings which create two identical dispersion lines. The gratings have a sinusoidal transmission function, which produces a highly precise high-orders free spectrum. An x-ray mirror interacts with one of the dispersion lines, and the mirror efficiency curve as a function of wavelength is extracted. Mirror efficiency shows good agreement with the literature, and evidence of water layer may justify the need of in situ calibration.

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

    SciTech Connect

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

    2009-03-03

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

  20. X-Ray Scatter Correction on Soft Tissue Images for Portable Cone Beam CT

    PubMed Central

    Aootaphao, Sorapong; Thongvigitmanee, Saowapak S.; Rajruangrabin, Jartuwat; Thanasupsombat, Chalinee; Srivongsa, Tanapon; Thajchayapong, Pairash

    2016-01-01

    Soft tissue images from portable cone beam computed tomography (CBCT) scanners can be used for diagnosis and detection of tumor, cancer, intracerebral hemorrhage, and so forth. Due to large field of view, X-ray scattering which is the main cause of artifacts degrades image quality, such as cupping artifacts, CT number inaccuracy, and low contrast, especially on soft tissue images. In this work, we propose the X-ray scatter correction method for improving soft tissue images. The X-ray scatter correction scheme to estimate X-ray scatter signals is based on the deconvolution technique using the maximum likelihood estimation maximization (MLEM) method. The scatter kernels are obtained by simulating the PMMA sheet on the Monte Carlo simulation (MCS) software. In the experiment, we used the QRM phantom to quantitatively compare with fan-beam CT (FBCT) data in terms of CT number values, contrast to noise ratio, cupping artifacts, and low contrast detectability. Moreover, the PH3 angiography phantom was also used to mimic human soft tissues in the brain. The reconstructed images with our proposed scatter correction show significant improvement on image quality. Thus the proposed scatter correction technique has high potential to detect soft tissues in the brain. PMID:27022608

  1. X-Ray Scatter Correction on Soft Tissue Images for Portable Cone Beam CT.

    PubMed

    Aootaphao, Sorapong; Thongvigitmanee, Saowapak S; Rajruangrabin, Jartuwat; Thanasupsombat, Chalinee; Srivongsa, Tanapon; Thajchayapong, Pairash

    2016-01-01

    Soft tissue images from portable cone beam computed tomography (CBCT) scanners can be used for diagnosis and detection of tumor, cancer, intracerebral hemorrhage, and so forth. Due to large field of view, X-ray scattering which is the main cause of artifacts degrades image quality, such as cupping artifacts, CT number inaccuracy, and low contrast, especially on soft tissue images. In this work, we propose the X-ray scatter correction method for improving soft tissue images. The X-ray scatter correction scheme to estimate X-ray scatter signals is based on the deconvolution technique using the maximum likelihood estimation maximization (MLEM) method. The scatter kernels are obtained by simulating the PMMA sheet on the Monte Carlo simulation (MCS) software. In the experiment, we used the QRM phantom to quantitatively compare with fan-beam CT (FBCT) data in terms of CT number values, contrast to noise ratio, cupping artifacts, and low contrast detectability. Moreover, the PH3 angiography phantom was also used to mimic human soft tissues in the brain. The reconstructed images with our proposed scatter correction show significant improvement on image quality. Thus the proposed scatter correction technique has high potential to detect soft tissues in the brain. PMID:27022608

  2. Observation of Actin Filaments in Leydig Cells with a Contact-type Soft X-ray Microscope with Laser Plasma X-ray Source

    NASA Astrophysics Data System (ADS)

    Kado, Masataka; Ishino, Masahiko; Tamotsu, Satoshi; Yasuda, Keiko; Kishimoto, Maki; Nishikino, Masaharu; Kinjo, Yasuhito; Shinohara, Kunio

    Actin filaments in Leydig cells from mouse testes have been observed with a contact-type soft x-ray microscope with laser plasma x-ray source. The Leydig cells were fixed with paraformaldehyde, stained with Phalloidin, and observed with a confocal laser microscope prior to the observation with x-ray microscope. Obtained images by both of the confocal laser microscopy and the x-ray microscopy were directly compared and revealed that not only position of actin filaments but also the shapes can be identified each other. The actin filaments in the x-ray images were clearly recognized and their structures were obtained in more detail compared to those in the confocal laser microscope images.

  3. Quantitative x-ray magnetic circular dichroism mapping with high spatial resolution full-field magnetic transmission soft x-ray spectro-microscopy

    SciTech Connect

    Robertson, MacCallum J.; Agostino, Christopher J.; N'Diaye, Alpha T.; Chen, Gong; Im, Mi-Young; Fischer, Peter

    2015-05-07

    The spectroscopic analysis of X-ray magnetic circular dichroism (XMCD), which serves as strong and element-specific magnetic contrast in full-field magnetic transmission soft x-ray microscopy, is shown to provide information on the local distribution of spin (S) and orbital (L) magnetic moments down to a spatial resolution of 25 nm limited by the x-ray optics used in the x-ray microscope. The spatially resolved L/S ratio observed in a multilayered (Co 0.3 nm/Pt 0.5 nm) × 30 thin film exhibiting a strong perpendicular magnetic anisotropy decreases significantly in the vicinity of domain walls, indicating a non-uniform spin configuration in the vertical profile of a domain wall across the thin film. Quantitative XMCD mapping with x-ray spectro-microscopy will become an important characterization tool for systems with topological or engineered magnetization inhomogeneities.

  4. Quantitative x-ray magnetic circular dichroism mapping with high spatial resolution full-field magnetic transmission soft x-ray spectro-microscopy

    NASA Astrophysics Data System (ADS)

    Robertson, MacCallum J.; Agostino, Christopher J.; N'Diaye, Alpha T.; Chen, Gong; Im, Mi-Young; Fischer, Peter

    2015-05-01

    The spectroscopic analysis of X-ray magnetic circular dichroism (XMCD), which serves as strong and element-specific magnetic contrast in full-field magnetic transmission soft x-ray microscopy, is shown to provide information on the local distribution of spin (S) and orbital (L) magnetic moments down to a spatial resolution of 25 nm limited by the x-ray optics used in the x-ray microscope. The spatially resolved L/S ratio observed in a multilayered (Co 0.3 nm/Pt 0.5 nm) × 30 thin film exhibiting a strong perpendicular magnetic anisotropy decreases significantly in the vicinity of domain walls, indicating a non-uniform spin configuration in the vertical profile of a domain wall across the thin film. Quantitative XMCD mapping with x-ray spectro-microscopy will become an important characterization tool for systems with topological or engineered magnetization inhomogeneities.

  5. A Soft X-Ray Transient in the M31 Bulge

    NASA Astrophysics Data System (ADS)

    Williams, Benjamin F.; Garcia, Michael R.; McClintock, Jeffrey E.; Primini, Frank A.; Murray, Stephen S.

    2006-01-01

    We have examined a probable soft X-ray transient source in the M31 bulge at R.A.=0h42m41.814s+/-0.08", decl.=41deg16'35.86"+/-0.07". On the three occasions we observed the source, its spectrum was soft (kTin~1 keV). The brightest detection of the source was on 2004 July 17, with a 0.3-7 keV luminosity of ~5×1037 ergs s-1. The only previous detection of the source was in 1979 by the Einstein observatory. The multiple detections over 25 years suggest that the duty cycle of the source is in the range 0.02-0.06. Coordinated HST ACS imaging before, during, and after the outburst revealed no variable optical source within the position errors of the X-ray source. The optical data place a firm upper limit on the brightness of the counterpart of the X-ray outburst of B>24.7, suggesting that the binary has a period <~5.2 days. The X-ray spectrum and lack of bright stars at the source location indicate that the source was a soft transient event occurring in a low-mass X-ray binary, making this source a good black hole candidate in M31.

  6. Resolving the Origin of the Diffuse Soft X-ray Background

    NASA Technical Reports Server (NTRS)

    Smith, Randall K.; Foster, Adam R.; Edgar, Ricard J.; Brickhouse, Nancy S.; Sanders, Wilton T.

    2012-01-01

    In January 1993, the Diffuse X-ray Spectrometer (DXS) measured the first high-resolution spectrum of the diffuse soft X-ray background between 44-80A. A line-dominated spectrum characteristic of a 10(exp 6)K collisionally ionized plasma' was expected but while the observed spectrum was clearly line-dominated, no model would fit. Then in 2003 the Cosmic Hot Interstellar Plasma Spectrometer (CHIPS) launched and observed the diffuse extreme-ultraviolet (EUV) spectrum between 90- 265A. Although many emission lines were again expected; only Fe IX at 171.1A was detected. The discovery of X-rays from comets led to the realization that heavy ions (Z=6-28) in the solar wind will emit soft X-rays as the ions interact via charge exchange with neutral atoms in the heliosphere and geocorona. Using a new model for solar wind charge exchange (SWCX) emission, we show that the diffuse soft X-ray background can be understood as a combination of emission from charge exchange onto the slow and fast solar wind together with a more distant and diffuse hot (10(exp 6)K) plasma.

  7. Soft X-ray flare spectra. [existence of high temperature plasmas in solar flares

    NASA Technical Reports Server (NTRS)

    Doschek, G. A.; Meekins, J. F.

    1973-01-01

    Large solar flares produce intense soft X-ray emission, indicating the existence of high temperature plasmas that coexist in time with the plasmas responsible for the normally observed brightenings in H-alpha. The time behavior of the X-ray flux, as revealed, for example, by ion chamber detectors on the series of Solrad monitoring satellites, appears to roughly mimic the intensity-time behavior of the H-alpha flare, insofar as start times, times of maximum flux, and approximate decay times are concerned. In recent years, soft X-ray spectra of both active regions and solar flares have been obtained by instruments flown on spacecraft such as the Orbiting Solar Observatory (OSO) series. The disbursing elements used were Bragg crystals, and in the 8 Angstrom region the resolution is typically approximately 1200. This paper discusses the observed characteristics of X-ray flare spectra and spectroscopic diagnostics for determining electron temperatures, electron densities, and departures from ionization equilibrium within the soft X-ray emitting plasma.

  8. Simulation of Soft X-Ray Emission Lines from the Missing Baryons

    NASA Astrophysics Data System (ADS)

    Fang, Taotao; Croft, Rupert A. C.; Sanders, Wilton T.; Houck, John; Davé, Romeel; Katz, Neal; Weinberg, David H.; Hernquist, Lars

    2005-04-01

    We study the soft X-ray emission (0.1-1 keV) from the warm-hot intergalactic medium (WHIM) in a hydrodynamic simulation of a cold dark matter universe. Our main goal is to investigate how such emission can be explored with a combination of imaging and spectroscopy and to motivate future X-ray missions. We first present high-resolution images of the X-ray emission in several energy bands in which emission from different ion species dominates. We pick three different areas to study the high-resolution spectra of X-rays from the WHIM: (1) a galaxy group, (2) a filament, and (3) an underluminous region. By taking into account the background X-ray emission from AGNs and foreground emission from the Galaxy, we compute composite X-ray spectra of the selected regions. We briefly investigate angular clustering of the soft X-ray emission, finding a strong signal. Most interestingly, the combination of high spectral resolution and angular information allows us to map the emission from the WHIM in three dimensions. We cross-correlate the positions of galaxies in the simulation with this redshift map of emission and detect the presence of six different ion species (Ne IX, Fe XVII, O VII, O VIII, N VII, and C VI) in the large-scale structure traced by the galaxies. Finally, we show how such emission can be detected and studied with future X-ray satellites, with particular attention to a proposed mission, the Missing Baryon Explorer (MBE). We present simulated observations of the WHIM gas with MBE.

  9. Diagnosing the accretion flow in ultraluminous X-ray sources using soft X-ray atomic features

    NASA Astrophysics Data System (ADS)

    Middleton, Matthew J.; Walton, Dominic J.; Fabian, Andrew; Roberts, Timothy P.; Heil, Lucy; Pinto, Ciro; Anderson, Gemma; Sutton, Andrew

    2015-12-01

    The lack of unambiguous detections of atomic features in the X-ray spectra of ultraluminous X-ray sources (ULXs) has proven a hindrance in diagnosing the nature of the accretion flow. The possible association of spectral residuals at soft energies with atomic features seen in absorption and/or emission and potentially broadened by velocity dispersion could therefore hold the key to understanding much about these enigmatic sources. Here we show for the first time that such residuals are seen in several sources and appear extremely similar in shape, implying a common origin. Via simple arguments we assert that emission from extreme colliding winds, absorption in a shell of material associated with the ULX nebula and thermal plasma emission associated with star formation are all highly unlikely to provide an origin. Whilst CCD spectra lack the energy resolution necessary to directly determine the nature of the features (i.e. formed of a complex of narrow lines or intrinsically broad lines), studying the evolution of the residuals with underlying spectral shape allows for an important, indirect test for their origin. The ULX NGC 1313 X-1 provides the best opportunity to perform such a test due to the dynamic range in spectral hardness provided by archival observations. We show through highly simplified spectral modelling that the strength of the features (in either absorption or emission) appears to anticorrelate with spectral hardness, which would rule out an origin via reflection of a primary continuum and instead supports a picture of atomic transitions in a wind or nearby material associated with such an outflow.

  10. Performance of the ASTRO-H Soft X-ray Telescope (SXT-1)

    NASA Astrophysics Data System (ADS)

    Okajima, Takashi; Serlemitsos, P. J.; Soong, Y.

    2013-04-01

    The X-ray astronomy satellite, ASTRO-H, being developed under the collaboration among JAXA, NASA's GSFC and ESA, will have two Soft X-ray Telescopes (SXTs), among other instruments onboard, with a sensitive energy band up to 15 keV. One is for an X-ray micro-calorimeter detector and the other for an X-ray CCD detector. The SXT uses a conically approximated Wolter I grazing incidence optic implemented by thin aluminum foil substrates with thickness of 0.152, 0.229, and 0.305 mm. X-ray reflecting surface is a gold thin layer (2000A) transferred from a smooth glass mandrel to the substrate by a replication method using an epoxy buffer layer (12 um). It is similar to the Suzaku X-ray telescope, but with larger diameter (45 cm) and longer focal length (5.6 m). Recently we have completed the first flight SXT (SXT-1). X-ray measurments with a diverging beam at the Goddard 100-m beamline found an angular resolution to be 1.13 arcmin (HPD) at 4.5 keV. Since we also found that this performance has radial dependence, the angular resolution will be different for a parallel beam, i.e. in orbit. It will be measured by the full performance characterization at ISAS/JAXA, Japan, later this year. SXT-1 has successfully gone through environmental testing (vibration and thermal) and the performance ramains same. In this paper, we will report X-ray test results obtained at the Goddard X-ray beamline.

  11. Wide-band, high-resolution soft x-ray spectrometer for the Electron Beam Ion Trap

    SciTech Connect

    Brown, G.V.; Beiersdorfer, P.; Widmann, K.

    1999-01-01

    We have constructed two wide-band, high-resolution vacuum flat crystal spectrometers and implemented them on the Electron Beam Ion Trap located at the Lawrence Livermore National Laboratory. Working in unison, these spectrometers can measure an x-ray bandwidth {le}9 {Angstrom} in the soft x-ray region below 21 {Angstrom}. In order to achieve this large bandwidth each spectrometer houses either two 125 mm {times} 13 mm {times} 2 mm RAP (rubidium acid phthalate, 2d=26.121 {Angstrom}), two 114 mm {times} 13 mm {times} 2 mm TlAP (thallium acid phthalate, 2d=25.75 {Angstrom}) crystals, or some combination thereof, for dispersion and two position sensitive proportional counters for detection of x rays. The spectrometers are used to measure wavelengths and relative intensities of the L-shell line emission from FethinspXVII{endash}XXIV for comparison with spectra obtained from astrophysical and laboratory plasmas. The wide wavelength coverage attainable by these spectrometers makes it possible to measure all the L-shell emission from a given iron ion species simultaneously. {copyright} {ital 1999 American Institute of Physics.}

  12. Wide-band, high-resolution soft x-ray spectrometer for the Electron Beam Ion Trap

    NASA Astrophysics Data System (ADS)

    Brown, G. V.; Beiersdorfer, P.; Widmann, K.

    1999-01-01

    We have constructed two wide-band, high-resolution vacuum flat crystal spectrometers and implemented them on the Electron Beam Ion Trap located at the Lawrence Livermore National Laboratory. Working in unison, these spectrometers can measure an x-ray bandwidth ⩽9 Å in the soft x-ray region below 21 Å. In order to achieve this large bandwidth each spectrometer houses either two 125 mm × 13 mm × 2 mm RAP (rubidium acid phthalate, 2d=26.121 Å), two 114 mm × 13 mm × 2 mm TlAP (thallium acid phthalate, 2d=25.75 Å) crystals, or some combination thereof, for dispersion and two position sensitive proportional counters for detection of x rays. The spectrometers are used to measure wavelengths and relative intensities of the L-shell line emission from Fe XVII-XXIV for comparison with spectra obtained from astrophysical and laboratory plasmas. The wide wavelength coverage attainable by these spectrometers makes it possible to measure all the L-shell emission from a given iron ion species simultaneously.

  13. The high-field magnet endstation for X-ray magnetic dichroism experiments at ESRF soft X-ray beamline ID32.

    PubMed

    Kummer, K; Fondacaro, A; Jimenez, E; Velez-Fort, E; Amorese, A; Aspbury, M; Yakhou-Harris, F; van der Linden, P; Brookes, N B

    2016-03-01

    A new high-field magnet endstation for X-ray magnetic dichroism experiments has been installed and commissioned at the ESRF soft X-ray beamline ID32. The magnet consists of two split-pairs of superconducting coils which can generate up to 9 T along the beam and up to 4 T orthogonal to the beam. It is connected to a cluster of ultra-high-vacuum chambers that offer a comprehensive set of surface preparation and characterization techniques. The endstation and the beam properties have been designed to provide optimum experimental conditions for X-ray magnetic linear and circular dichroism experiments in the soft X-ray range between 400 and 1600 eV photon energy. User operation started in November 2014. PMID:26917134

  14. Efficient alignment scheme for zone-plates-based transmission soft X-ray microscope

    NASA Astrophysics Data System (ADS)

    Lim, Jun; Shin, Hyun-Joon; Hong, Chung Ki

    2010-12-01

    Alignment and operation of a zone-plate (ZP)-based transmission soft X-ray microscope (TXM) is difficult and time consuming, especially when the TXM has no dedicated X-ray source. We introduce here an efficient TXM alignment scheme. The TXM employed is a simple in-situ-experiment-capable setup. It includes ultrahigh-vacuum (UHV)-compatible conflat flanges and is mountable in tandem with any soft X-ray synchrotron radiation beamlines. Obtaining zeroth- and first-order diffracted (condenser-zone-plate [CZP]-focused) beams simultaneously by means of the objective zone plate (OZP) is the most essential step in the alignment scheme. We were able to acquire, in one hour at a radiation wavelength of 2.49 nm, an image of 50 nm spatial resolution.

  15. X-pinch soft x-ray source dynamics at a subnanosecond time resolution

    NASA Astrophysics Data System (ADS)

    Artyomov, A. P.; Fedunin, A. V.; Chaikovsky, S. A.; Ratakhin, N. A.

    2015-11-01

    The paper reports on an experimental study of the X-pinch soft x-ray source dynamics at a subnanosecond time resolution with the use of an x-ray imaging technique based on an AXIS-NX streak camera. The study was performed on a compact generator with a current amplitude of 300 kA to a short-circuit load and current rise time of 180 ns. It is shown that in the spectral range 1-1.55 keV, the X-pinch soft x-ray source in whole represents a set of sources which can be radially offset by ∼ 10 microns about the X-pinch axis. Each of the sources generates a pulse of duration 0.2-0.7 ns. The interval between the formation of the sources and hence between their radiation pulses is 0.5 ns and longer.

  16. Soft X-Ray Imaging of spin dynamics at high spatial and temporalresolution

    SciTech Connect

    Mesler, Brooke L.; Fischer, Peter; Chao, Weilun; Anderson, Erik H.

    2007-06-01

    Soft X-ray microscopy provides element specific magnetic imaging with a spatial resolution down to 15nm. At XM-1, the full-field soft X-ray microscope at the Advanced Light Source in Berkeley, a stroboscopic pump and probe setup has been developed to study fast magnetization dynamics in ferromagnetic elements with a time resolution of 70ps which is set by the width of the X-ray pulses from the synchrotron. Results obtained with a 2 {micro}m x 4 {micro}m x 45nm rectangular permalloy sample exhibiting a seven domain Landau pattern reveal dynamics up to several nsec after the exciting magnetic field pulse. Domain wall motion, a gyrotropic vortex motion, and a coupling between vortices in the rectangular geometry are observed.

  17. Soft X-Ray Irradiation of Silicates: Implications for Dust Evolution in Protoplanetary Disks

    NASA Astrophysics Data System (ADS)

    Ciaravella, A.; Cecchi-Pestellini, C.; Chen, Y.-J.; Muñoz Caro, G. M.; Huang, C.-H.; Jiménez-Escobar, A.; Venezia, A. M.

    2016-09-01

    The processing of energetic photons on bare silicate grains was simulated experimentally on silicate films submitted to soft X-rays of energies up to 1.25 keV. The silicate material was prepared by means of a microwave assisted sol–gel technique. Its chemical composition reflects the Mg2SiO4 stoichiometry with residual impurities due to the synthesis method. The experiments were performed using the spherical grating monochromator beamline at the National Synchrotron Radiation Research Center in Taiwan. We found that soft X-ray irradiation induces structural changes that can be interpreted as an amorphization of the processed silicate material. The present results may have relevant implications in the evolution of silicate materials in X-ray-irradiated protoplanetary disks.

  18. Ultra-soft x-ray absorption spectroscopy: A bulk and surface probe of materials

    SciTech Connect

    Fischer, D.A. ); Mitchell, G.E.; Dekoven, B.M. ); Yeh, A.T.; Gland, J.L. ); Moodenbaugh, A.R. )

    1993-01-01

    Direct comparisons between surface and bulk of diverse materials can be made by simultaneous electron yield (5 nm depth sensitivity) and fluorescence yield (200 nm) ultra soft x-ray absorption spectroscopy measurements utilizing a rapid sample interchange apparatus. For example the orientations of functional groups have been characterized at and near the surface of a series of model polymeric materials highlighting the chemical and molecular sensitivity of ultra soft x-ray absorption spectroscopy. In addition we discuss a bulk sensitive use of fluorescence yield to non destructively study a buried metal polymer interface. A second bulk sensitive example is the use of fluorescence yield oxygen K near edge x-ray spectroscopy as a method to determine the hole state density of high Tc materials.

  19. Ultra-soft x-ray absorption spectroscopy: A bulk and surface probe of materials

    SciTech Connect

    Fischer, D.A.; Mitchell, G.E.; Dekoven, B.M.; Yeh, A.T.; Gland, J.L.; Moodenbaugh, A.R.

    1993-06-01

    Direct comparisons between surface and bulk of diverse materials can be made by simultaneous electron yield (5 nm depth sensitivity) and fluorescence yield (200 nm) ultra soft x-ray absorption spectroscopy measurements utilizing a rapid sample interchange apparatus. For example the orientations of functional groups have been characterized at and near the surface of a series of model polymeric materials highlighting the chemical and molecular sensitivity of ultra soft x-ray absorption spectroscopy. In addition we discuss a bulk sensitive use of fluorescence yield to non destructively study a buried metal polymer interface. A second bulk sensitive example is the use of fluorescence yield oxygen K near edge x-ray spectroscopy as a method to determine the hole state density of high Tc materials.

  20. Magnetogram and soft X-ray comparisons of XBP and ER

    NASA Technical Reports Server (NTRS)

    Golub, Leon; Harvey, Karen L.; Webb, David F.

    1986-01-01

    The potential importance of the smallest emerging flux regions on the sun was discussed in numerous publications. The association between the objects seen in ground-based data, such as high resolution magnetrons or H alpha and soft X-ray data has produced results which are often contradictory. In the hope of resolving the present impasse, as much simultaneous soft X-ray and magnetogram data as possible were assembled in order to clarify the situation. It was found that separation of magnetic features into chance encounters and emerging flux makes some difference in overlapp with X-ray bright points (XBPs), although the effect is not overwhelming. The difference in solar cycle dependence between XBP and ephemeral regions is not explainable in terms of the results.

  1. Spatial and spectral features of soft diffuse X ray background seen by the Einstein observatory

    NASA Technical Reports Server (NTRS)

    Micela, G.; Harnden, F. R.; Rosner, R., Jr.; Sciortino, S.; Vaiana, G. S.

    1989-01-01

    A survey of the diffuse soft X-ray background as seen directly by the Einstein Observatory Imaging Proportional Counter (IPC) is presented. A source free region of the detector 1 by 1 degree field is used. The background in the 0.16 to 3.5 keV spectral region is viewed. The data covers roughly 5 percent of the sky, with some bias in coverage towards the galactic plane. The moderate energy resolution of the IPC enables the characterization and the production of maps of the background as a function of energy within the Einstein passband. The results are compared with previous observations of the diffuse X-ray background. The implications for galactic structure and for the soft component of the extragalactic X-ray background are discussed.

  2. Resolving the origin of the diffuse soft X-ray background

    SciTech Connect

    Smith, Randall K.; Foster, Adam R.; Edgar, Richard J.; Brickhouse, Nancy S.

    2014-05-20

    The ubiquitous diffuse soft (1/4 keV) X-ray background was one of the earliest discoveries of X-ray astronomy. At least some of the emission may arise from charge exchange between solar wind ions and neutral atoms in the heliosphere, but no detailed models have been fit to the available data. Here, we report on a new model for charge exchange in the solar wind, which, when combined with a diffuse hot plasma component, filling the Local Cavity provides a good fit to the only available high-resolution soft X-ray and extreme ultraviolet spectra using plausible parameters for the solar wind. The implied hot plasma component is in pressure equilibrium with the local cloud that surrounds the solar system, creating for the first time a self-consistent picture of the local interstellar medium.

  3. Development of ellipsoidal focusing mirror for soft x-ray and extreme ultraviolet light

    NASA Astrophysics Data System (ADS)

    Mimura, Hidekazu; Takei, Yoshinori; Saito, Takahiro; Kume, Takehiro; Motoyama, Hiroto; Egawa, Satoru; Takeo, Yoko; Higashi, Takahiro

    2015-08-01

    Mirrors are key devices for creating various systems in optics. Focusing X-ray and extreme ultraviolet (EUV) light requires mirror surfaces with an extremely high accuracy. The figure of an ellipsoidal mirror is obtained by rotating an elliptical profile, and using such a mirror, soft X-ray and EUV light can be focused to dimensions on the order of nanometers without chromatic aberration. Although the theoretical performance of ellipsoidal mirrors is extremely high, the fabrication of an ideal ellipsoidal mirror remains problematic. Based on this background, we have been working to develop a fabrication system for ellipsoidal mirrors. In this proceeding, we briefly introduce the fabrication process and the soft X-ray focusing performance of the ellipsoidal mirror fabricated using the proposed process.

  4. Determination of half-dose depth in skin for soft x-rays

    SciTech Connect

    Harley, N.H.; Kolber, A.B.; Altman, S.M.; Gladstein, A.H.; Buchanan, S.; Marx, J.; Grisewood, E.; Kopf, A.

    1982-09-01

    Unlike superficial x-rays, the soft x-rays normally used in dermatologic practice spare unaffected underlying organs during treatment of cutaneous malignancies. However, since the dose with depth from soft x-rays varies markedly, it is important to know this relationship for optimal therapeutic results. The peak kilovoltage, and thus the energy of the beam, is generally selected so that the dose to the base of the lesion is one-half the surface dose. An absorbed dose of 3,400 rads to the surface and a dose of about one-half this amount to the base of most malignant lesions is one standard protocol for optimal therapeutic results. An accurate value of half-depth dose in skin is therefore necessary and is readily obtained from ordinary half-value layer measurements using the technic described.

  5. Electron-density measurements in hohlraums using soft-x-ray deflectometry

    SciTech Connect

    Decker, C.D.; London, R.A.; Harte, J.A.; Powers, L.V.; Trebes, J.E.

    1998-05-01

    This paper presents design calculations for experiments that measure electron densities of laser heated hohlraums with soft-x-ray moir{acute e} deflectometry. Hydrodynamical simulations of the hohlraums are analyzed to obtain deflection angles of the probing beam and x-ray emission from the hohlraum. The deflection angles and resulting moir{acute e} fringe shifts and fringe contrast are predicted to be sufficient to infer electron-density gradients from measurements. In addition, the self-emission is found to be much lower than that of the probing laser beam, giving a good signal-to-noise ratio. In conclusion, moir{acute e} deflectometry with soft-x-ray lasers has the potential to give valuable information about the electron density in laser driven hohlraums. {copyright} {ital 1998} {ital The American Physical Society}

  6. Detection of soft X-rays with NEA III-V photocathodes. [Negative Electron Affinity X-ray detector for astronomy

    NASA Technical Reports Server (NTRS)

    Bardas, D.; Kellogg, E.; Murray, S.; Enck, R., Jr.

    1978-01-01

    A description is presented of the results of tests on an X-ray photomultiplier containing a negative electron affinity (NEA) photocathode. This device makes it possible to investigate the response of the NEA photocathode to X-rays of various energies. The obtained data provide a basis for the determination of the photoelectron yield and energy resolution of the considered photocathode as a function of energy in the range from 0.8 to 3 keV. The investigation demonstrates the feasibility of using an NEA III-V photocathode for the detection of soft X-rays.

  7. Energetics of impulsive solar flares: Correlating BATSE hard x-ray bursts and the solar atmosphere's soft x-ray response

    NASA Technical Reports Server (NTRS)

    Newton, Elizabeth

    1996-01-01

    This investigation has involved the correlation of BATSE-observed solar hard X-ray emission with the characteristics of soft X-ray emitting plasma observed by the Yohkoh Bragg Crystal Spectrometers. The goal was to test the hypothesis that localized electron beam heating is the dominant energy transport mechanism in impulsive flares, as formulated in the thick-target electron-heated model of Brown.

  8. The detection of soft X-rays with charged coupled detectors

    NASA Technical Reports Server (NTRS)

    Burstein, P.; Davis, John M.

    1989-01-01

    The characteristics of an ideal soft X-ray imaging detector are enumerated. Of recent technical developments the CCD or charge coupled device goes furthest to meeting these requirements. Several properties of CCDs are described with reference to experimental work and their application to practical instruments is reviewed.

  9. A rotating tomographic imager for solar extreme-ultraviolet/soft X-ray emission

    NASA Astrophysics Data System (ADS)

    Davila, Joseph M.; Thompson, W. T.

    1992-04-01

    A concept is presented for a high-resolution EUV/soft-X-ray imager that has much in common with the medical imaging procedure of tomography. The resulting instrument is compatible with a simpler, less costly spin-axis-stabilized spacecraft. To demonstrate the fidelity of the reconstruction procedure, the observation and reconstruction is simulated to compare the results with the original image.

  10. A rotating tomographic imager for solar extreme-ultraviolet/soft X-ray emission

    NASA Technical Reports Server (NTRS)

    Davila, Joseph M.; Thompson, W. T.

    1992-01-01

    A concept is presented for a high-resolution EUV/soft-X-ray imager that has much in common with the medical imaging procedure of tomography. The resulting instrument is compatible with a simpler, less costly spin-axis-stabilized spacecraft. To demonstrate the fidelity of the reconstruction procedure, the observation and reconstruction is simulated to compare the results with the original image.

  11. Utilizing ablation of solids to characterize a focused soft X-ray laser beam

    NASA Astrophysics Data System (ADS)

    Chalupský, J.; Juha, L.; Kuba, J.; Hájková, V.; Cihelka, J.; Homer, P.; Kozlová, M.; Mocek, T.; Polan, J.; Rus, B.; Krzywinsky, J.; Sobierajski, R.; Wabnitz, H.; Feldhaus, J.; Tiedtke, K.; the, And

    2007-05-01

    An advanced time integrated method has been developed for soft X-ray pulsed laser beam characterization. A technique based on poly (methyl methacrylate) - PMMA laser induced ablation has been used for beam investigations of soft X-ray laser sources like FLASH (Free-electron LASer in Hamburg; formerly known as VUV FEL and/or TTF2 FEL) and plasma-based Ne-like Zn laser performed at PALS (Prague Asterix Laser System). For the interaction experiments reported here, the FLASH system provided ultra-short pulses (~10-fs) of 21.7-nm radiation. The PMMA ablation was also induced by plasma-based Ne-like Zn soft X-ray laser pumped by NIR beams at the PALS facility. This quasi-steady-state (QSS) soft X-ray laser provides 100-ps pulses of 21.2-nm radiation, i.e. at a wavelength very close to that of FLASH but with about 5,000 times longer pulses. In both cases, the PMMA samples were irradiated by a single shot with a focused beam under normal incidence conditions. Characteristics of ablated craters obtained with AFM (Atomic Force Microscope) and Nomarski microscopes were utilized for profile reconstruction and diameter determination of the focused laser beams ablating the PMMA surface.

  12. Gain dynamics measurement in injection-seeded soft x-ray laser plasma amplifiers

    NASA Astrophysics Data System (ADS)

    Wang, Yong; Wang, S.; Li, L.; Oliva, E.; Thuy Le, T. T.; Ros, D.; Berrill, M.; Dunn, J.; Zeitoun, Ph.; Yin, L.; Luther, B.; Rocca, J. J.

    2013-10-01

    Herein we report the first measurement of the gain dynamics in a soft x-ray plasma amplifier seeded by high harmonic pulses. A sequence of two time-delayed spatially-overlapping high harmonic pulses was injected into a λ = 18.9 nm Ni-like Mo plasma amplifier to measure the regeneration of the population inversion that follows the gain depletion caused by the amplification of the first seed pulse. Collisional excitation is observed to re-establish population inversion depleted during the amplification of the seed pulse in about ~1.75 ps. The measured gain-recovery time is compared to model simulations to gain insight on the population inversion mechanisms that create the transient gain in these amplifiers. This result supports the concept of a soft x-ray laser amplification scheme based on the continuous extraction of energy from a soft x-ray plasma-based amplifier by an stretched seed pulse has the potential to generate ultra-intense fully phase-coherent soft x-ray laser pulses. Work supported by AMOS program, Office of Basic Energy Sciences of the US DoE, and the NSF ERC Program with equipment developed under NSF Award MRI-ARRA 09-561, and by LASERLAB3-INREX European project and SHYLAX plus CIBORG RTRA `Triangle de la Physique.'

  13. Soft x-ray laser gain measurements in a recombining plasma column

    SciTech Connect

    Suckewer, S.; Skinner, C.H.; Milchberg, H.; Keane, C.; Voorhees, D.

    1985-03-01

    An enhancement of approx. 100 of stimulated emission over spontaneous emission of the CVI 182 A line (one-pass gain approx. = 6.5) was measured in a recombining, magnetically confined plasma column by two independent techniques using intensity calibrated XUV monochromators. Additional confirmation that the enhancement was due to stimulated emission has been obtained with a soft x-ray mirror.

  14. Soft-x-ray projection lithography experiments using Schwarzschild imaging optics

    SciTech Connect

    Tichenor, D.A.; Kubiak, G.D.; Malinowski, M.E.; Stulen, R.H.; Haney, S.J.; Berger, K.W.; Brown, L.A. ); Sweatt, W.C. ); Bjorkholm, J.E.; Freeman, R.R.; Himel, M.D.; MacDowell, A.A.; Tennant, D.M.; Wood II, O.R. ); Bokor, J.; Jewell, T.E.; Mansfield, W.M.; Waskiewicz, W.K.; White, D.L.; Windt, D.L. )

    1993-12-01

    Soft-x-ray projection imaging is demonstrated by the use of 14-nm radiation from a laser plasma source and a single-surface multilayer-coated ellipsoidal condenser. Aberrations in the condenser and the Schwarzschild imaging objective are characterized and correlated with imaging performance. A new Schwarzschild housing, designed for improved alignment stability, is described.

  15. 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.

  16. A soft x-ray undulator for the U5 beamline at NSLS

    SciTech Connect

    Viccaro, P.J.; Shenoy, G.K.; Kim, S.H.; Bader, S.D.

    1988-10-01

    The magnetic structure and spectral properties of a 7.5-cm, 30-period hybrid undulator are described. The device will be installed at the U5 port of the VUV storage ring at Brookhaven National Laboratory and will be a tunable source of very high brilliance soft x-ray radiation over the range of 13 from approximately 150 eV.

  17. High numerical aperture tabletop soft x-ray diffraction microscopy with 70-nm resolution

    PubMed Central

    Sandberg, Richard L.; Song, Changyong; Wachulak, Przemyslaw W.; Raymondson, Daisy A.; Paul, Ariel; Amirbekian, Bagrat; Lee, Edwin; Sakdinawat, Anne E.; La-O-Vorakiat, Chan; Marconi, Mario C.; Menoni, Carmen S.; Murnane, Margaret M.; Rocca, Jorge J.; Kapteyn, Henry C.; Miao, Jianwei

    2008-01-01

    Light microscopy has greatly advanced our understanding of nature. The achievable resolution, however, is limited by optical wavelengths to ≈200 nm. By using imaging and labeling technologies, resolutions beyond the diffraction limit can be achieved for specialized specimens with techniques such as near-field scanning optical microscopy, stimulated emission depletion microscopy, and photoactivated localization microscopy. Here, we report a versatile soft x-ray diffraction microscope with 70- to 90-nm resolution by using two different tabletop coherent soft x-ray sources—a soft x-ray laser and a high-harmonic source. We also use field curvature correction that allows high numerical aperture imaging and near-diffraction-limited resolution of 1.5λ. A tabletop soft x-ray diffraction microscope should find broad applications in biology, nanoscience, and materials science because of its simple optical design, high resolution, large depth of field, 3D imaging capability, scalability to shorter wavelengths, and ultrafast temporal resolution. PMID:18162534

  18. Soft X-ray spectrum of laser-produced aluminum plasma

    SciTech Connect

    Vergunova, G. A.; Grushin, A. S.; Kologrivov, A. A.; Novikov, V. G.; Osipov, M. V.; Puzyrev, V. N. Rozanov, V. B. Starodub, A. N. Yakushev, O. F.

    2015-05-15

    Soft X-ray spectra (30–70 Å) of aluminum plasma have been measured in experiments carried out at the Kanal-2 laser facility at laser intensities of (1–7) × 10{sup 13} W/cm{sup 2}. It is shown that the measured spectra satisfactory agree with those calculated using the RADIAN numerical code.

  19. Optical constants in the extreme ultraviolet and soft X-ray region

    NASA Technical Reports Server (NTRS)

    Rife, J. C.; Osantowski, J. F.

    1982-01-01

    The nature of optical constants and their measurement by reflection or absorption techniques in the extreme ultraviolet and soft X-ray spectral region from 30 to 3000 eV is discussed with emphasis on mirror design. Sources of optical constant data are mentioned and reflectance measurements for SiC and Kanigen between 40 and 200 eV are reported.

  20. The Soft X-ray Flux Surface Shape Diagnostic on the PEGASUS Toroidal Experiment

    NASA Astrophysics Data System (ADS)

    Tritz, K. L.; Fonck, R. J.; Schooff, R. J.; Sontag, A. C.

    2000-10-01

    Flux surface shape information can be used as a constraint for reconstruction of the plasma current and q profiles for shaped, low-aspect ratio toroidal devices. To exploit this sensitivity of shape to plasma profiles, an equilibrium code was developed to incorporate flux surface shape information from linearized chordal soft X-ray (SXR) measurement inputs from a 2-D tangentially viewing pinhole camera. This equilibrium code uses a nonlinear least squares fitting to facilitate the inclusion of the SXR measurement constraints. The pinhole camera consists of a 2mm diameter pinhole projection onto a 150mm diameter viewport coated with a high-efficiency phosphor, P43. A 40mm diameter MCP image intensifier is lens coupled to the phosphor for maximum sensitivity, resulting in a signal to noise ratio of <1% from photon statistics. The MCP is optically coupled to a fast framing CCD camera allowing for frame rates of 1000 frames/sec. and exposure times < 100 μs. First results from a prototype system will be achieved with a commercial intensified camera.

  1. Comparison of two regularization methods for soft x-ray tomography at Tore Supra

    NASA Astrophysics Data System (ADS)

    Jardin, A.; Mazon, D.; Bielecki, J.

    2016-04-01

    Soft x-ray (SXR) emission in the range 0.1–20 keV is widely used to obtain valuable information on tokamak plasma physics, such as particle transport, magnetic configuration or magnetohydrodynamic activity. In particular, 2D tomography is the usual plasma diagnostic to access the local SXR emissivity. The tomographic inversion is traditionally performed from line-integrated measurements of two or more cameras viewing the plasma in a poloidal cross-section, like at Tore Supra (TS). Unfortunately, due to the limited number of measured projections and presence of noise, the tomographic reconstruction of SXR emissivity is a mathematical ill-posed problem. Thus, obtaining reliable results of the tomographic inversion is a very challenging task. In order to perform the reconstruction, inversion algorithms implemented in present tokamaks use a priori information as additional constraints imposed on the plasma SXR emissivity. Among several potential inversion methods, some of them have been identified as well suited to tokamak plasmas. The purpose of this work is to compare two promising inversion methods, i.e. the minimum fisher information method already used at TS and planned for WEST configuration, and the alternative 2nd order Phillips–Tikhonov regularization with smoothness constraints imposed on the second derivative norm. Respective accuracy of both reconstruction methods as well as overall robustness and computational time are studied, using several synthetic SXR emissivity profiles. Finally, a real case is studied through tomographic reconstruction from TS SXR database.

  2. SOFT-X RAY DIAGNOSTICS AND TREATMENTS FOR FUTURE REAL TIME APPLICATIONS

    SciTech Connect

    Pacella, D.; Mazon, D.

    2008-03-12

    This paper offers a preliminary review of the present diagnostics and data analysis techniques in the domain of Soft X-ray (SXR) emissions of fusion magnetic plasmas, including a short description of the theoretical background as well. Particular attention is devoted to the wide use of SXR tomography and impurity transport simulation. In their actual form, these techniques are not adequate to future real time applications. For this goal a step forward in the diagnosing and analysis of SXR emissions is required. The following part of the paper is therefore dedicated to the discussion of these improvements. The first one is the SXR tomography optimized for real time applications, like that one developed at Tore Supra (Cadarache, France). Fast 2-D tomographic inversions using different techniques (regularisation of Minimum Fisher, Maximum entropy, Zernicke polynomial expansions), will be optimized to be performed in a few millisecond time scale, crucial for MHD analysis, mode detection and localisation. The other goal to be pursued is the energy resolved imaging, now possible with a gas Micro Pattern Gas Detector with pixel read-out, as recently demonstrated at FTU (Frascati, Italy) and at NSTX (Princeton NJ, US), together with an ad hoc modeling of SXR emissions, compatible with future real time applications.

  3. Current Profile and Magnetic Structure Measurements through Tangential Soft X-Ray Imaging in Compact Tori

    SciTech Connect

    Fonck, Raymond J.

    2004-07-12

    This report describes the fabrication and tests of a tangentially imaging soft X-ray (SXR) camera diagnostic for fusion energy plasma research. It can be used for the determination of the current distribution in strongly shaped toroidal magnetically confined plasmas, such as those found in spherical tori or advanced tokamaks. It included the development of both an appropriate imaging SXR camera and image analysis techniques necessary to deduce the plasma shape and current distribution. The basic camera concept consists of a tangentially viewing pinhole imaging system with thin-film SXR filters, a scintillator screen to provide SXR to visible conversion, a fast shuttering system, and an sensitive visible camera imaging device. The analysis approach consists of integrating the 2-D SXR image data into a Grad-Shafranov toroidal equilibrium solver code to provide strong constraints on the deduced plasma current and pressure profiles. Acceptable sensitivity in the deduced current profile can be obtained if the relative noise in the measured image can be kept in the range of 1% or less. Tests on the Pegasus Toroidal Experiment indicate very flat safety factor profiles in the plasma interior.

  4. Atmospheric parameters of a soft X ray selected set of hot DA white dwarfs

    NASA Astrophysics Data System (ADS)

    Kidder, Kenneth Mark

    Soft x-ray/EUV observations provide a sensitive means of probing the structure and composition of the atmospheres of hot hydrogen-rich (DA) white dwarf stars. This is due to the fact that soft x-rays originate from hotter, deeper layers of the photosphere than do longer wavelengths. A primary aim of this research is to expand the sample of DA's observed with soft x-ray instrumentation through a search for serendipitous observations of catalogued hot DA white dwarfs in existing soft x-ray databases. The positional coincidences of 31 catalogued DA's (McCook and Sion 1987) were examined in Einstein IPC and EXOSAT LE fields. As a result, three soft x-ray sources have been identified corresponding to the white dwarfs (WD0631 + 107, WD1113 + 413 and WD0425 + 168) and a fourth source which is probably not due to photospheric thermal emission from the coincident white dwarf. The three detected DA's have relatively low effective temperatures (27,200 +/- 400 K, 26,200 +/- 1100 K and 24,000 +/- 500 K, respectively), as determined independently using complementary optical and UV spectroscopy. Applying these temperature constraints to the soft x-ray photometric data, the photospheres of these stars must be composed of effectively pure hydrogen (n(He)/n(H) less than 10 exp -5), although the hottest star, WD0631 + 107, can have trace levels of homogeneously mixed helium less than 10 exp -4.2. The analysis of the soft x-ray observations are supplemented with independent determinations of temperature, gravity, and V magnitude. The method of determination employed is to fit the well-sampled wings of the broad hydrogen absorption profiles with self-consistent model atmosphere predictions. Precise temperatures and gravities are obtained by fitting the observed profiles independently, then jointly determining a consistent solution for each object. In this effort, a ground-based observation program was established to obtain high quality spectra of the Balmer delta and gamma lines and in

  5. Soft X-Ray Spectrometer Using 100-Pixel STJ Detectors for Synchrotron Radiation

    SciTech Connect

    Shiki, Shigetomo; Zen, Nobuyuki; Ukibe, Masahiro; Ohkubo, Masataka

    2009-12-16

    Fluorescent X-ray absorption fine structure (XAFS) is an important tool for material analysis, especially for the measurement of chemical states or local structures of elements. Semiconductor detectors are usually used for separating the fluorescent of elements in question from background fluorescence. However, the semiconductor detectors cannot always discriminate K-lines of light elements and L-lines of various elements as different X-ray peaks at an energy range below about 3 keV. Superconducting tunnel junction (STJ) detectors are promising device for the soft X-ray at synchrotron radiation beam lines because of excellent energy resolution, high detection efficiency, and high counting rate. We are constructing a fluorescent X-ray spectrometer having 100-pixel array of STJs with 200 {mu}m square. The array detector is mounted on a liquid cryogen-free {sup 3}He cryostat. The sensitive area is the largest among the superconducting X-ray spectrometers operating at synchrotron beam lines. Each pixel is connected to a room temperature readout circuit that consists of a charge sensitive amplifier and a pulse height analyzer. The spectrometer will achieve a total solid angle of {approx}0.01 sr and a maximum counting rate of more than 1 M count per second. The present status of developments of our fluorescent X-ray spectrometer was reported.

  6. Temperature and emission measure from GOES soft X-ray measurements

    NASA Astrophysics Data System (ADS)

    Garcia, Howard A.

    1994-10-01

    This paper provides a detailed description of the procedure used for computing color temperature and emission measure from Geostationary Operational Environmental Satellite (GOES) X-ray data, including a table of constants for Synchronous Meteorological Satellite (SMS) and GOES X-ray sensors that are necessary for reducing the archived data from these satellites. Temperature and theoretical current tables were constructed, for individual GOES sensors, from laboratory calibrations of instrument responses and from synthetic solar X-ray spectra generated by two models of solar thermal X-ray emission: Raymond-Smith and Mewe-Alkemade. Example tables are shown and others are available on request. Errors that may be incurred from the use of GOES X-ray data in the computation of flare temperatures and emission measures may be classified under four major groups: instrument induced errors, including errors of calibration and random measurements errors; environmentally induced errors, due primarily to the ambient energetic electron background; solar influences, including the consequences of the isothermal assumption and the single-source assumption; and uncertainties in the modelled solar synthetic spectrum. These error sources are discussed separately, and a rough estimation of the collective error is made where this is quantitatively feasible. Finally, temperatures and emission measures are computed from GOES data and are compared with those derived from Solar Maximum Mission (SMM) and Hinotori soft X-ray spectrometer data and from broadband photometric data from the PROGNOZ satellite.

  7. Overview of nanoscale NEXAFS performed with soft X-ray microscopes.

    PubMed

    Guttmann, Peter; Bittencourt, Carla

    2015-01-01

    Today, in material science nanoscale structures are becoming more and more important. Not only for the further miniaturization of semiconductor devices like carbon nanotube based transistors, but also for newly developed efficient energy storage devices, gas sensors or catalytic systems nanoscale and functionalized materials have to be analysed. Therefore, analytical tools like near-edge X-ray absorption fine structure (NEXAFS) spectroscopy has to be applied on single nanostructures. Scanning transmission X-ray microscopes (STXM) as well as full-field transmission X-ray microscopes (TXM) allow the required spatial resolution to study individual nanostructures. In the soft X-ray energy range only STXM was used so far for NEXAFS studies. Due to its unique setup, the TXM operated by the Helmholtz-Zentrum Berlin (HZB) at the electron storage ring BESSY II is the first one in the soft X-ray range which can be used for NEXAFS spectroscopy studies which will be shown in this review. Here we will give an overview of the different microscopes used for NEXAFS studies and describe their advantages and disadvantages for different samples. PMID:25821700

  8. Overview of nanoscale NEXAFS performed with soft X-ray microscopes

    PubMed Central

    Bittencourt, Carla

    2015-01-01

    Summary Today, in material science nanoscale structures are becoming more and more important. Not only for the further miniaturization of semiconductor devices like carbon nanotube based transistors, but also for newly developed efficient energy storage devices, gas sensors or catalytic systems nanoscale and functionalized materials have to be analysed. Therefore, analytical tools like near-edge X-ray absorption fine structure (NEXAFS) spectroscopy has to be applied on single nanostructures. Scanning transmission X-ray microscopes (STXM) as well as full-field transmission X-ray microscopes (TXM) allow the required spatial resolution to study individual nanostructures. In the soft X-ray energy range only STXM was used so far for NEXAFS studies. Due to its unique setup, the TXM operated by the Helmholtz-Zentrum Berlin (HZB) at the electron storage ring BESSY II is the first one in the soft X-ray range which can be used for NEXAFS spectroscopy studies which will be shown in this review. Here we will give an overview of the different microscopes used for NEXAFS studies and describe their advantages and disadvantages for different samples. PMID:25821700

  9. Resonant soft X-ray scattering study of twist bend nematic phase

    NASA Astrophysics Data System (ADS)

    Zhu, Chenhui; Young, Anthony; Wang, Cheng; Hexemer, Alexander; Li, Quan; Lavrentovich, Oleg; Walba, David; Tuchband, Michael; Shuai, Min; Clark, Noel

    Liquid crystals (LCs) form many interesting nano-scale structures, many of which can be probed with X-ray scattering techniques, typically hard X-rays due to its high penetrating power. However, in the hard X-ray regime, the scattering contrast of some LC nanostructures can be extremely low due to their weak electron density modulation. Here we show it is possible to use resonant soft x-rays to probe the helical pitch of the newly discovered twist bend nematic phase, which is purely a twist bend structure with no electron density modulation. The in-situ temperature dependent measurement will be presented and discussed. This work together with our previous study on the helical nanofilament B4 phase shows the great potential of soft x-ray scattering in liquid crystals. Supported by the Director of the Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.

  10. iWF-MAXI: Soft X-ray Transient Monitor on the ISS

    NASA Astrophysics Data System (ADS)

    Kawai, Nobuyuki; Tomida, Hiroshi; Ueno, Shiro; Kimura, Masashi; Ebisawa, Ken; Yatsu, Yoichi; Arimoto, Makoto; Mihara, Tatehiro; Serino, Motoko; Tsunemi, Hiroshi; Kohmura, Takayoshi; Sakamoto, Takanori; Negoro, Hitoshi; Ueda, Yoshihiro; Tsuboi, Yohko; Yoshida, Atsumasa

    2015-08-01

    iWF-MAXI is an X-ray transient monitor mission proposed for the ISS/JEM, starting in 2018-2019.It has four main scientific goals:(1) To find and localize the X-ray counterparts of gravitational wave events, which are expected to be detected by the next generation gravitational wave detectors such as Advance LIGO and KAGRA in late 2010's.(2) To detect short soft X-ray transients such as stellar flares, nova ignitions, and supernova shock breakouts, and promptly notify the world.(3) To trigger on short high-energy transients such as gamma-ray bursts and tidal disruption events, and promptly disseminate their locations to the community.(4) To detect the onset of activities from black hole binaries, neutron star binaries, and active galactic nuclei (AGN), and issue alerts to the astronomical community of the world.Its main scientific instrument is the Soft X-ray Large Solid Angle Camera (SLC). It is sensitive in the energy range of 0.7--10 keV with a localization accuracy of 0.1 degres. It will detect short transient events like GRBs with durations from a fraction of a second to minutes that occur in its large large field of view (>10% of the entire sky) .With the orbital revolution of the ISS, iWF-MAXI scans much larger sky area in 90 minutes, and looks for slower events such as outbursts of X-ray binaries.

  11. Soft X-ray spectromicroscopy for speciation, quantitation and nano-eco-toxicology of nanomaterials.

    PubMed

    Lawrence, J R; Swerhone, G D W; Dynes, J J; Korber, D R; Hitchcock, A P

    2016-02-01

    There is a critical need for methods that provide simultaneous detection, identification, quantitation and visualization of nanomaterials at their interface with biological and environmental systems. The approach should allow speciation as well as elemental analysis. Using the intrinsic X-ray absorption properties, soft X-ray scanning transmission X-ray spectromicroscopy (STXM) allows characterization and imaging of a broad range of nanomaterials, including metals, oxides and organic materials, and at the same time is able to provide detailed mapping of biological components. Thus, STXM offers considerable potential for application to research on nanomaterials in biology and the environment. The potential and limitations of STXM in this context are discussed using a range of examples, focusing on the interaction of nanomaterials with microbial cells, biofilms and extracellular polymers. The studies outlined include speciation and mapping of metal-containing nanomaterials (Ti, Ni, Cu) and carbon-based nanomaterials (multiwalled carbon nanotubes, C60 fullerene). The benefits of X-ray fluorescence detection in soft X-ray STXM are illustrated with a study of low levels of Ni in a natural river biofilm. PMID:25088794

  12. Dissociation of the benzene molecule by ultraviolet and soft X-rays in circumstellar environment

    NASA Astrophysics Data System (ADS)

    Boechat-Roberty, H. M.; Neves, R.; Pilling, S.; Lago, A. F.; de Souza, G. G. B.

    2009-04-01

    Benzene molecules, present in the proto-planetary nebula CRL 618, are ionized and dissociated by ultraviolet (UV) and X-ray photons originated from the hot central star and by its fast wind. Ionic species and free radicals produced by these processes can lead to the formation of new organic molecules. The aim of this work is to study the photoionization and photodissociation processes of the benzene molecule, using synchrotron radiation and time-of-flight mass spectrometry. Mass spectra were recorded at different energies corresponding to the vacuum UV (21.21 eV) and soft X-ray (282-310 eV) spectral regions. The production of ions from the benzene dissociative photoionization is here quantified, indicating that C6H6 is more efficiently fragmented by soft X-ray than UV radiation, where 50 per cent of the ionized benzene molecules survive to UV dissociation while only about 4 per cent resist to X-rays. Partial ion yields of H+ and small hydrocarbons, such as C2H+2, C3H+3, C4H+2, are determined as a function of photon energy. Absolute photoionization and dissociative photoionization cross-sections have also been determined. From these values, half-life of benzene molecule due to UV and X-ray photon fluxes in CRL 618 was obtained.

  13. Combined constraints on intergalactic dust from quasar colours and the soft X-ray background

    NASA Astrophysics Data System (ADS)

    Johansson, Joel; Mörtsell, Edvard

    2012-11-01

    Unless properly corrected for, the existence of intergalactic dust will introduce a redshift-dependent magnitude offset to standard candle sources. This would lead to overestimated luminosity distances compared to a dust-free universe and bias the cosmological parameter estimation as derived from, e.g., Type Ia supernova observations. In this paper, we model the optical extinction and X-ray scattering properties of intergalactic dust grains to constrain the intergalactic opacity using a combined analysis of observed quasar colours and the soft X-ray background. Quasar colours effectively constrain the amount of intergalactic dust grains smaller than ˜0.2 μm, to the point where we expect the corresponding systematic error in the Type Ia supernova magnitude-redshift relation to be sub-dominant. Soft X-ray background observations are helpful in improving the constraints on very large dust grains for which the amount of optical reddening is very small and therefore is more difficult to correct for. Our current upper limit corresponds to ˜0.25 mag dimming at optical wavelengths for a source at redshift z = 1, which is too small to alleviate the need for dark energy but large in terms of relative error. However, we expect it to be possible to lower this bound considerably with an improved understanding of the possible sources of the X-ray background, in combination with observations of compact X-ray sources such as active galactic nuclei.

  14. 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.

  15. A compact soft X-ray microscope using an electrode-less Z-pinch source

    NASA Astrophysics Data System (ADS)

    Horne, S. F.; Silterra, J.; Holber, W.

    2009-09-01

    Soft X-rays (< 1Kev) are of medical interest both for imaging and microdosimetry applications. X-ray sources at this low energy present a technological challenge. Synchrotrons, while very powerful and flexible, are enormously expensive national research facilities. Conventional X-ray sources based on electron bombardment can be compact and inexpensive, but low x-ray production efficiencies at low electron energies restrict this approach to very low power applications. Laser-based sources tend to be expensive and unreliable. Energetiq Technology, Inc. (Woburn, MA, USA) markets a 92 eV, 10W(2pi sr) electrode-less Z-pinch source developed for advanced semiconductor lithography. A modified version of this commercial product has produced 400 mW at 430 eV (2pi sr), appropriate for water window soft X-ray microscopy. The US NIH has funded Energetiq to design and construct a demonstration microscope using this source, coupled to a condenser optic, as the illumination system. The design of the condenser optic matches the unique characteristics of the source to the illumination requirements of the microscope, which is otherwise a conventional design. A separate program is underway to develop a microbeam system, in conjunction with the RARAF facility at Columbia University, NY, USA. The objective is to develop a focused, sub-micron beam capable of delivering > 1 Gy/second to the nucleus of a living cell. While most facilities of this type are coupled to a large and expensive particle accelerator, the Z-pinch X-ray source enables a compact, stand-alone design suitable to a small laboratory. The major technical issues in this system involve development of suitable focusing X-ray optics. Current status of these programs will be reported. (Supported by NIH grants 5R44RR022488-03 and 5R44RR023753-03)

  16. Solar flares with similar soft but different hard X-ray emissions: case and statistical studies

    NASA Astrophysics Data System (ADS)

    Sharykin, Ivan N.; Struminsky, Alexei B.; Zimovets, Ivan V.; Gan, Wei-Qun

    2016-01-01

    From the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) catalog we select events which have approximately the same GOES class (high C - low M or 500-1200 counts s-1 within the RHESSI 6-12 keV energy band), but with different maximal energies of detected hard X-rays. The selected events are subdivided into two groups: (1) flares with X-ray emissions observed by RHESSI up to only 50 keV and (2) flares with hard X-ray emission observed also above 50 keV. The main task is to understand observational peculiarities of these two flare groups. We use RHESSI X-ray data to obtain spectral and spatial information in order to find differences between selected groups. Spectra and images are analyzed in detail for six events (case study). For a larger number of samples (85 and 28 flares in the low-energy and high-energy groups respectively) we only make some generalizations. In spectral analysis we use the thick-target model for hard X-ray emission and one temperature assumption for thermal soft X-ray emission. RHESSI X-ray images are used for determination of flare region sizes. Although thermal and spatial properties of these two groups of flares are not easily distinguishable, power law indices of hard X-rays show significant differences. Events from the high-energy group generally have a harder spectrum. Therefore, the efficiency of chromospheric evaporation is not sensitive to the hardness of nonthermal electron spectra but rather depends on the total energy flux of nonthermal electrons.

  17. Soft X-Ray Irradiation of Pure Carbon Monoxide Interstellar Ice Analogues

    NASA Astrophysics Data System (ADS)

    Ciaravella, A.; Jiménez-Escobar, A.; Muñoz Caro, G. M.; Cecchi-Pestellini, C.; Candia, R.; Giarrusso, S.; Barbera, M.; Collura, A.

    2012-02-01

    There is an increasing evidence for the existence of large organic molecules in the interstellar and circumstellar medium. Very few among such species are readily formed in conventional gas-phase chemistry under typical conditions of interstellar clouds. Attention has therefore focused on interstellar ices as a potential source of these relatively complex species. Laboratory experiments show that irradiation of interstellar ice analogues by fast particles or ultraviolet radiation can induce significant chemical complexity. However, stars are sources of intense X-rays at almost every stage of their formation and evolution. Such radiation may thus provide chemical changes in regions where ultraviolet radiation is severely inhibited. After H2O, CO is often the most abundant component of icy grain mantles in dense interstellar clouds and circumstellar disks. In this work we present irradiation of a pure carbon monoxide ice using a soft X-ray spectrum peaked at 0.3 keV. Analysis of irradiated samples shows formation of CO2, C2O, C3O2, C3, C4O, and CO3/C5. Comparison of X-rays and ultraviolet irradiation experiments, of the same energy dose, shows that X-rays are more efficient than ultraviolet radiation in producing new species. With the exception of CO2, X-ray photolysis induces formation of a larger number of products with higher abundances, e.g., C3O2 column density is about one order of magnitude higher in the X-ray experiment. To our knowledge this is the first report on X-ray photolysis of CO ices. The present results show that X-ray irradiation represents an efficient photo-chemical way to convert simple ices to more complex species.

  18. Development of the ASTRO-H Soft X-ray Telescope (SXT): Engineering Model Performance

    NASA Astrophysics Data System (ADS)

    Okajima, Takashi; Serlemitsos, P. J.; Soong, Y.

    2011-09-01

    The X-ray astronomy satellite, ASTRO-H, being developed under the collaboration among JAXA, NASA's GSFC and ESA, will have two Soft X-ray Telescopes (SXTs), among other instruments onboard, with a sensitive energy band up to 15 keV. One is for an X-ray micro-calorimeter detector and the other for an X-ray CCD detector. The SXT uses a conically approximated Wolter I grazing incidence optic implemented by thin aluminum foil substrates with thickness of 0.152, 0.229, and 0.305 mm. X-ray reflecting surface is a gold thin layer ( 2000A) transferred from a smooth glass mandrel to the substrate by a replication method using an epoxy buffer layer (12 um). It is similar to the Suzaku XRT, but with larger diameter (45 cm) and longer focal length (5.6 m). Goals of angular resolution and effective area are 1 arcmin and 390 cm2 at 6 keV, respectively. We made several improvements from Suzaku to ASTRO-H, such as thicker substrates, more forming mandrels, thinner epoxy layer for replication, stiffer housings, precise alignment bars, etc. With all these changes, we have fabricated the engineering test unit of the SXT. In this paper, we will discuss all the changes made, their effects, and report X-ray performance of the SXT test unit. An angular resolution of the test unit was measured at new Goddard X-ray calibration facility (100 m X-ray beamline) and was found to be 65 arcsec at 4.5 keV. We will also discuss further improvements toward the flight unit to be delivered to JAXA in 2012.

  19. Implementation of a new multiple monochromatic x-ray 2D imager at NIF

    NASA Astrophysics Data System (ADS)

    Kyrala, G. A.; Martinson, D.; Polk, P. J.; Gravlin, T.; Schmitt, M. J.; Johnson, R.; Murphy, T. J.; Lopez, F. E.; Oertel, J. A.; House, A.; Wood, R.; Lee, J.; Haugh, M.

    2013-09-01

    We will describe the installation and wavelength calibration of a multiple monochromatic imager [MMI]1 to be used on mix experiments at National Ignition Facility [NIF]2. The imager works between 8 and 13 keV, has a spatial resolution of 16 micrometers and generates many images each with an energy bandwidth of ~80 eV. The images are recorded either on image plates or on gated x-ray detectors. We will describe: how we aligned the instrument on the bench using visible light, how we checked the alignment and determined the energy range using a k-alpha x-ray source, and how we installed and aligned the instrument to the NIF target chamber.

  20. An Unusual Spectral State of an Ultraluminous Very Soft X-Ray Source during Outburst

    NASA Astrophysics Data System (ADS)

    Kong, A. K. H.; Di Stefano, R.

    2005-10-01

    We report the results of Chandra and XMM-Newton observations of a new outburst of an ultraluminous X-ray source in M101. During a Chandra monitoring observation of M101, M101 ULX-1 was found to be in outburst in 2004 December, the second outburst in 2004. The peak bolometric luminosity is about 3×1040 ergs s-1 (7×1039 ergs s-1 in 0.3-7 keV). The outburst spectra are very soft and can generally be fitted with a blackbody model, with temperatures of 40-80 eV, similar to supersoft X-ray sources in the Milky Way and in the Magellanic Clouds. In one Chandra observation, the source spectrum appears to be harder with a temperature of 150 eV. Such a spectral state is rarely seen in M101 ULX-1, and no X-ray source in the Milky Way shows this kind of spectrum. However, such an unusual spectral state very likely belongs to a new class of X-ray sources, quasi-soft X-ray sources, recently discovered in nearby galaxies. M101 ULX-1 returned to supersoft state in a subsequent XMM-Newton observation. Based on the two outbursts in 2004, the extremely high luminosity (Lbol=1040-1041 ergs s-1), very soft X-ray spectra (kT=40-150 eV), transient behavior, and state transition provide strong evidence that M101 ULX-1 harbors an intermediate-mass black hole.

  1. Twin robotic x-ray system for 2D radiographic and 3D cone-beam CT imaging

    NASA Astrophysics Data System (ADS)

    Fieselmann, Andreas; Steinbrener, Jan; Jerebko, Anna K.; Voigt, Johannes M.; Scholz, Rosemarie; Ritschl, Ludwig; Mertelmeier, Thomas

    2016-03-01

    In this work, we provide an initial characterization of a novel twin robotic X-ray system. This system is equipped with two motor-driven telescopic arms carrying X-ray tube and flat-panel detector, respectively. 2D radiographs and fluoroscopic image sequences can be obtained from different viewing angles. Projection data for 3D cone-beam CT reconstruction can be acquired during simultaneous movement of the arms along dedicated scanning trajectories. We provide an initial evaluation of the 3D image quality based on phantom scans and clinical images. Furthermore, initial evaluation of patient dose is conducted. The results show that the system delivers high image quality for a range of medical applications. In particular, high spatial resolution enables adequate visualization of bone structures. This system allows 3D X-ray scanning of patients in standing and weight-bearing position. It could enable new 2D/3D imaging workflows in musculoskeletal imaging and improve diagnosis of musculoskeletal disorders.

  2. Soft X-ray study of solar wind charge exchange from the Earth's magnetosphere : Suzaku observations and a future X-ray imaging mission concept

    NASA Astrophysics Data System (ADS)

    Ezoe, Y.; Ishisaki, Y.; Ohashi, T.; Ishikawa, K.; Miyoshi, Y.; Fujimoto, R.; Terada, N.; Kasahara, S.; Fujimoto, M.; Mitsuda, K.; Nishijo, K.; Noda, A.

    2013-12-01

    Soft X-ray observations of solar wind charge exchange (SWCX) emission from the Earth's magnetosphere using the Japanese X-ray astronomy satellite Suzaku are shown, together with our X-ray imaging mission concept to characterize the solar wind interaction with the magnetosphere. In recent years, the SWCX emission from the Earth's magnetosphere, originally discovered as unexplained noise during the soft X-ray all sky survey (Snowden et al. 1994), is receiving increased attention on studying geospace. The SWCX is a reaction between neutrals in exosphere and highly charged ions in the magnetosphere originated from solar wind. Robertson et al. (2005) modeled the SWCX emission as seen from an observation point 50 Re from Earth. In the resulting X-ray intensities, the magnetopause, bow shock and cusp were clearly visible. High sensitivity soft X-ray observation with CCDs onboard recent X-ray astronomy satellites enables us to resolve SWCX emission lines and investigate time correlation with solar wind as observed with ACE and WIND more accurately. Suzaku is the 5th Japanese X-ray astronomy satellite launched in 2005. The line of sight direction through cusp is observable, while constraints on Earth limb avoidance angle of other satellites often limits observable regions. Suzaku firstly detected the SWCX emission while pointing in the direction of the north ecliptic pole (Fujimoto et al. 2007). Using the Tsyganenko 1996 magnetic field model, the distance to the nearest SWCX region was estimated as 2-8 Re, implying that the line of sight direction can be through magnetospheric cusp. Ezoe et al. (2010) reported SWCX events toward the sub-solar side of the magnetosheath. These cusp and sub-solar side magnetosheath regions are predicted to show high SWCX fluxes by Robertson et al. (2005). On the other hand, Ishikawa et al. (2013) discovered a similarly strong SWCX event when the line of sight direction did not transverse these two regions. Motivated by these detections

  3. Polycapillary lenses for Soft-X-ray transmission: Model, comparison with experiments and potential application for tomographic measurements in tokamaks

    NASA Astrophysics Data System (ADS)

    Mazon, D.; Abadie, Q.; Dorchies, F.; Lecherbourg, L.; Mollard, A.; Malard, P.; Dabagov, S.

    2015-07-01

    In tokamaks, plasma emits as a volumetric Soft-X-ray (SXR) source. Emitted X-rays can give very useful information about plasma stability, shape and impurity content. Measuring the Soft X-ray (SXR) radiation ([0.1-20 keV]) of magnetic fusion plasmas is a standard way of accessing valuable information on particle transport and MagnetoHydroDynamic. Generally, like at Tore Supra in France, the analysis is performed with a 2D tomographic system composed of several cameras equipped with detectors like Silicon Barrier Diodes spread in periphery of the tokamak. Unfortunately, the strong constraints imposed by the environment of a tokamak reactor (high neutron fluxes, gamma and hard X-ray emission, high magnetic field and high radiofrequency powers) do not authorize to install in a close vicinity of the machine such detectors. We have thus investigated the possibility of using polycapillary lenses to transport the SXR information to several meters from the plasma, not necessarily in a straight line. The idea is to protect the SXR detector from the entire environment by a proper shielding. Different polycapillary lenses could be used for that purpose and have been tested in collaboration with CELIA (CEA-CNRS) of Bordeaux. Transmission of the order of 20% where observed for the low energetic part of the spectrum (down to 3 keV) while still 10% were observed for the remaining part (from 3 to 10 keV). In parallel a model of polycapillary transmission has been developed and validated against experiment. Results are presented confirming the great potential of polycapillary lenses for SXR transmission in tokamak plasma. Studies of the influence of geometrical parameters like diameter and curvature of the channels, on the photons transmission is also presented.

  4. Soft X-ray emission from the Lupus Loop and Sn 1006 supernova remnants

    NASA Technical Reports Server (NTRS)

    Winkler, P. F., Jr.; Hearn, D. R.; Richardson, J. A.; Behnken, J. M.

    1979-01-01

    X-ray maps of the Lupus region have been obtained in a raster scan observation from SAS 3. These show the Lupus Loop to be a faint extended source of soft X-rays with a temperature about 2.5 million K. The most prominent feature of the region is the A.D. 1006 supernova remnant, which is unexpectedly bright at 0.2-1.0 keV. One speculative interpretation of the low-energy flux from SN 1006 is as blackbody radiation from a hot neutron star.

  5. Demonstration of 12 nm resolution Fresnel zone plate lens based soft x-ray microscopy

    SciTech Connect

    Chao, W.; Kim, J.; Rekawa, S.; Fischer, P.; Anderson, E. H.

    2009-06-05

    To extend soft x-ray microscopy to a resolution of order 10 nm or better, we developed a new nanofabrication process for Fresnel zone plate lenses. The new process, based on the double patterning technique, has enabled us to fabricate high quality gold zone plates with 12 nm outer zones. Testing of the zone plate with the full-field transmission x-ray microscope, XM-1, in Berkeley, showed that the lens clearly resolved 12 nm lines and spaces. This result represents a significant step towards 10 nm resolution and beyond.

  6. Iridium/Iridium Silicide as an Oxidation Resistant Capping Layer for Soft X-ray Mirrors

    SciTech Connect

    Prisbrey, S; Vernon, S

    2004-04-05

    Rust on a sword, tarnish on the silverware, and a loss in reflectivity for soft x-ray mirrors are all caused by oxidation that changes the desired characteristics of a material. Methods to prevent the oxidation have varied over the centuries with the default method of a protective coating being the most common. The protective coating for x-ray mirrors is usually a self-limiting oxidized layer on the surface of the material that stops further oxidation of the material by limiting the diffusion of oxygen to the material underneath.

  7. Aplanatic Three-Mirror Objective for High-Magnification Soft X-Ray Microscopy

    SciTech Connect

    Toyoda, M.; Jinno, T.; Yanagihara, M.

    2011-09-09

    An innovative solution for high-magnification microscopy, based on attaching afocal optics for focal length reduction, is proposed. The solution, consisting of three spherical mirrors, allows one to enhance a magnification of a laboratory based soft x-ray microscope over 1000x, where movies with diffraction-limited resolution can be observed with an x-ray CCD. The design example, having a numerical aperture of 0.25, was successfully demonstrated both a high magnification and a large field of view.

  8. Soft x-ray-controlled dose deposition in yeast cells: techniques, model, and biological assessment

    NASA Astrophysics Data System (ADS)

    Milani, Marziale; Batani, Dimitri; Conti, Aldo; Masini, Alessandra; Costato, Michele; Pozzi, Achille; Turcu, I. C. Edmond

    1996-12-01

    A procedure is presented to release soft x-rays onto yeast cell membrane allegedly damaging the resident enzymatic processes connected with fermentation. The damage is expected to be restricted to regulating fermentation processes without interference with respiration. By this technique fermentation is followed leading to CO2 production, and respiration resulting in global pressure measurements. A solid state pressure sensor system has been developed linked to a data acquisition system. Yeast cells cultures have been investigated at different concentrations and with different nutrients. A non-monotone response in CO2 production as a function of the delivered x-ray dose is observed.

  9. Design of an imaging microscope for soft X-ray applications

    NASA Technical Reports Server (NTRS)

    Hoover, Richard B.; Shealy, David L.; Gabardi, David R.; Walker, Arthur B. C., Jr.; Lindblom, Joakim F.

    1988-01-01

    An imaging soft X-ray microscope with a spatial resolution of 0.1 micron and normal incidence multilayer optics is discussed. The microscope has a Schwarzschild configuration, which consists of two concentric spherical mirrors with radii of curvature which minimize third-order spherical aberration, coma, and astigmatism. The performance of the Stanford/MSFC Cassegrain X-ray telescope and its relevance to the present microscope are addressed. A ray tracing analysis of the optical system indicates that diffraction-limited performance can be expected for an object height of 0.2 mm.

  10. Standing-wave excited soft x-ray photoemission microscopy: application to Co microdot magnetic arrays

    SciTech Connect

    Gray, Alexander; Kronast, Florian; Papp, Christian; Yang, See-Hun; Cramm, Stefan; Krug, Ingo P.; Salmassi, Farhad; Gullikson, Eric M.; Hilken, Dawn L.; Anderson, Erik H.; Fischer, Peter; Durr, Hermann A.; Schneider, Claus M.; Fadley, Charles S.

    2010-10-29

    We demonstrate the addition of depth resolution to the usual two-dimensional images in photoelectron emission microscopy (PEEM), with application to a square array of circular magnetic Co microdots. The method is based on excitation with soft x-ray standing-waves generated by Bragg reflection from a multilayer mirror substrate. Standing wave is moved vertically through sample simply by varying the photon energy around the Bragg condition. Depth-resolved PEEM images were obtained for all of the observed elements. Photoemission intensities as functions of photon energy were compared to x-ray optical calculations in order to quantitatively derive the depth-resolved film structure of the sample.

  11. High-performance soft x-ray spectromicroscopy beamline at SSRF.

    PubMed

    Xue, Chaofan; Wang, Yong; Guo, Zhi; Wu, Yanqing; Zhen, Xiangjun; Chen, Min; Chen, Jiahua; Xue, Song; Peng, Zhongqi; Lu, Qipeng; Tai, Renzhong

    2010-10-01

    The Shanghai Synchrotron Radiation Facility (SSRF) is the first third-generation synchrotron facility in China and operated at an electron energy of 3.5 GeV. One of the seven beamlines in the first construction phase is devoted to soft x-ray spectromicroscopy and is equipped with an elliptically polarized undulator light source, a plane grating monochromator, and a scanning transmission x-ray microscope end station. Initial results reveal the high performance of this beamline, with an energy resolving power estimated to be over 10,000 at the argon L-edge and a spatial resolution better than 30 nm. PMID:21034086

  12. High-performance soft x-ray spectromicroscopy beamline at SSRF

    NASA Astrophysics Data System (ADS)

    Xue, Chaofan; Wang, Yong; Guo, Zhi; Wu, Yanqing; Zhen, Xiangjun; Chen, Min; Chen, Jiahua; Xue, Song; Peng, Zhongqi; Lu, Qipeng; Tai, Renzhong

    2010-10-01

    The Shanghai Synchrotron Radiation Facility (SSRF) is the first third-generation synchrotron facility in China and operated at an electron energy of 3.5 GeV. One of the seven beamlines in the first construction phase is devoted to soft x-ray spectromicroscopy and is equipped with an elliptically polarized undulator light source, a plane grating monochromator, and a scanning transmission x-ray microscope end station. Initial results reveal the high performance of this beamline, with an energy resolving power estimated to be over 10 000 at the argon L-edge and a spatial resolution better than 30 nm.

  13. Soft-x-ray spectroscopy of subpicosecond laser-produced plasmas

    NASA Astrophysics Data System (ADS)

    Krushelnick, K. M.; Tighe, W.; Suckewer, S.

    1996-02-01

    Experiments that examine the interaction of high-intensity subpicosecond laser radiation ( \\similar 1018 W / cm2) with solid targets are performed. Soft-x-ray spectra from interactions with Teflon and aluminum targets that imply the creation of high-temperature ( > 200 eV) high-density ( > 10 23 cm -3 ) plasmas are obtained. Effects of a prepulse on the plasma characteristics are examined. The applicability of short, intense laser pulses for the formation of population inversions on x-ray transitions during recombination of high-density plasmas is discussed. 42.55.Vc.

  14. Optically Triggered RXTE Observations of Soft X-Ray Transients (core Program)

    NASA Astrophysics Data System (ADS)

    We propose to use optical/infra-red observations from the SMARTS consortium to trigger RXTE observations of transient soft X-ray binaries. We will trigger on two kinds of events: 1) a rise from quiescence; 2) state transitions during an outburst. These RXTE data, together with data from our already approved Swift program, radio ATCA observations and the SMARTS data themselves, will provide broad-band coverage in optical/IR and X-ray bandpasses, which will be used to study accretion processes and jets in black holes and neutron stars.

  15. Instrumentation developments in scanning soft x-ray microscopy at the NSLS (invited)

    NASA Astrophysics Data System (ADS)

    Williams, Shawn; Jacobsen, Chris; Kirz, Janos; Maser, Jörg; Wirick, Sue; Zhang, Xiaodong; Ade, Harald; Rivers, Mark

    1995-02-01

    The Scanning Transmission Soft X-ray Microscope at the NSLS has been instrumented for the following new forms of imaging: (1) XANES microscopy for the mapping of chemical constituents and for absorption spectroscopy of small specimen areas; (2) luminescence microscopy for locating visible light emitting labels at the resolution determined by the size of the x-ray microprobe; and (3) dichroism microscopy for mapping the alignment of molecules whose absorption spectra are polarization dependent. Since the instrument is used mostly for the imaging of biological and other radiation sensitive materials, a cryostage is being planned to accommodate frozen hydrated specimens.

  16. Soft x-ray submicron imaging detector based on point defects in LiF

    SciTech Connect

    Baldacchini, G.; Bollanti, S.; Bonfigli, F.; Flora, F.; Di Lazzaro, P.; Lai, A.; Marolo, T.; Montereali, R.M.; Murra, D.; Faenov, A.; Pikuz, T.; Nichelatti, E.; Tomassetti, G.; Reale, A.; Reale, L.; Ritucci, A.; Limongi, T.; Palladino, L.; Francucci, M.; Martellucci, S.

    2005-11-15

    The use of lithium fluoride (LiF) crystals and films as imaging detectors for EUV and soft-x-ray radiation is discussed. The EUV or soft-x-ray radiation can generate stable color centers, emitting in the visible spectral range an intense fluorescence from the exposed areas. The high dynamic response of the material to the received dose and the atomic scale of the color centers make this detector extremely interesting for imaging at a spatial resolution which can be much smaller than the light wavelength. Experimental results of contact microscopy imaging of test meshes demonstrate a resolution of the order of 400 nm. This high spatial resolution has been obtained in a wide field of view, up to several mm{sup 2}. Images obtained on different biological samples, as well as an investigation of a soft x-ray laser beam are presented. The behavior of the generated color centers density as a function of the deposited x-ray dose and the advantages of this new diagnostic technique for both coherent and noncoherent EUV sources, compared with CCDs detectors, photographic films, and photoresists are discussed.

  17. Study of NbC thin films for soft X-ray multilayer applications

    SciTech Connect

    Singh, Amol E-mail: rrcat.amol@gmail.com; Modi, Mohammed H.; Lodha, G. S.; Rajput, Parasmani; Jha, S. N.

    2015-06-24

    Compound materials are being used in soft x-ray and Extreme ultraviolet (EUV) optics applications. Structural properties of compound materials changes drastically when ultrathin films are formed from bulk material. Structural properties need to be investigated to determine the suitability of compound materials in soft x-ray multilayer applications. In the present study Niobium carbide (NbC) thin films were deposited using ion beam sputtering of an NbC target on Si (100) substrate. Thickness roughness and film mass density was determined from the X-ray reflectivity (XRR) data. XRR data revealed that the film mass density was increasing with increase in film thickness. For 500Ǻ thick film, mass density of 6.85 g/cm{sup 3}, close to bulk density was found. Rms roughness for all the films was less than 10Å. Local structure of NbC thin films was determined from EXAFS measurements. The EXAFS data showed an increase in Nb-C and Nb-(C)-Nb peak ratio approaches towards bulk NbC with increasing thickness of NbC. From the present study, NbC thin films were found suitable for actual use in soft x-ray multilayer applications.

  18. Principal component analysis of solar flares in the soft X-ray flux

    NASA Technical Reports Server (NTRS)

    Teuber, D. L.; Reichmann, E. J.; Wilson, R. M.

    1979-01-01

    The paper considers principal component analysis of solar flares in the soft X-ray flux, a technique for extracting the salient features from a mass of data. The method applies particularly to the analysis of nonstationary ensembles, and its computations require the evaluation of eigenvalues of matrices. The Eispack matrix eigen system routines were used to analyze full-disk proportional-counter data from the X-ray event analyzer which was part of the Skylab experiment. Empirical orthogonal functions were derived for events in the soft X-ray spectrum between 2.5 and 20 A during different time periods, indicating that about 90% of the cumulative power of each analyzed flare is contained in the largest eigenvector. The first two largest eigenvectors are sufficient for an empirical curve fit through the raw data and a characterization of solar flares in the soft X-ray flux, and power spectra of two largest eigenvectors reveal a reported periodicity of about 5 min.

  19. High-resolution multiwire proportional soft x-ray diagnostic measurements on TCV

    NASA Astrophysics Data System (ADS)

    Sushkov, A.; Andreev, V.; Camenen, Y.; Pochelon, A.; Klimanov, I.; Scarabosio, A.; Weisen, H.

    2008-02-01

    A multiwire proportional x-ray (MPX) detector is used on the TCV tokamak (Tokamak à configuration variable) as a high spatial and temporal resolution soft x-ray emissivity imaging diagnostic. The MPX system consists of 64 vertically viewing channels and has been designed to complement the existing TCV soft x-ray tomography system by enhancing the spatial resolution. The MPX detector is suitable for the measurement of fast and localized phenomena and can be used, for instance, for the observation of magnetohydrodynamic activity, for the characterization of transport barriers or for an improved determination of the electron cyclotron heating power deposition profile. The MPX detector operates in continuous-current mode and measures the plasma soft x-ray emission in the 3-30keV range with a radial resolution of about 5mm—1% of plasma diameter—and a frequency bandwidth of 50kHz. A detailed description of the MPX detector construction and the principle of its operation are given. The properties of the detector in photon-counting and continuous-current operation modes are studied. The implementation of the system on TCV and experimental results illustrating the potential of the diagnostic are also presented.

  20. A multiwavelength study of the Eridanus soft X-ray enhancement

    NASA Technical Reports Server (NTRS)

    Burrows, D. N.; Singh, K. P.; Nousek, J. A.; Garmire, G. P.; Good, J.

    1993-01-01

    We present soft X-ray, N(H), and IR maps of the Eridanus soft X-ray enhancement. Soft X-ray maps from the HEAO 1 A-2 LED experiment, processed with a maximum entropy method (MEM) algorithm, show that the enhancement consists of two distinct components: a large hook-shaped component and a small circular component at different temperatures. Both of these are located in 'holes' in the IR emission, and they correspond to N(H) features at very different velocities. The dust surrounding the X-ray enhancements appears to be associated with several high-latitude molecular clouds, which allow us to obtain a probable distance of about 130 pc to the near edge of the main enhancement. The total power emitted by the hot gas is then about 10 exp 35 to 10 exp 36 ergs/s. We consider alternative interpretations of these objects as adiabatic supernova remnants or as stellar wind bubbles and conclude that they are more likely to be stellar wind bubbles, possibly reheated by a SN explosion in the case of the main, hook-shaped object.

  1. Pulsed Capillary Discharge Operated As A Compact Soft X-Ray Source

    NASA Astrophysics Data System (ADS)

    Valdivia, M. P.; Wyndham, E. S.; Favre, M.; Valenzuela, J. C.

    2010-07-01

    We analyze experimental results of radiation emission from a compact pulsed capillary ns discharge source, designed for soft x-ray applications, operated in Nitrogen and N/He mixtures at voltages in the range of 18-24kV. The discharge operates in an alumina capillary of length 21mm and 1.6mm inner diameter. The electrical energy stored is ~0.5 J with peak current of ~5kA. Fast charging from an IGBT based pulsed power circuit allows operation at 35-150 Hz. Characteristic time-integrated Nitrogen spectra were recorded from 10-220 Å with clear evidence of He-like Nitrogen line at 28.9 Å, which represents a possible source for a water window soft x-ray microscope. Time-evolution measurements show the influence of axial electron beams, generated by hollow cathode dynamics, on the x-ray emission. We discuss optimal frequency of operation, voltage applied, geometrical and pressure conditions for cathode and anode, for soft x-ray generation. Time-integrated MCP images of a filtered slit-wire system delivered an estimate of the maximum emission energy of our source, as well as clear evidence of full wall detachment, of ~100μm in radial size for the entire emission range.

  2. Large-scale coronal structures in EUV and soft X-rays in solar cycle 23

    NASA Astrophysics Data System (ADS)

    Benevolenskaya, E. E.; Kosovichev, A. G.; Scherrer, P. H.; Lemen, J. R.; Slater, G. L.

    2002-06-01

    We have analyzed the EIT/SOHO data in four EUV lines (171 Å, 195 Å, 284 Å and 304 Å) and soft X-ray YOHKOH data in two filters (AlMg and Al) in the form of coronal synoptic maps for the period 1996 - 2001 yrs. Two types of the bright structures have been detected in EUV in the axisymmetrically averaged synoptic maps. The structures of the first type migrate equatorward as the solar cycle progresses. They are related to complexes of sunspot activity and display the "butterfly"-type distribution. The structures of the second type migrate polarward and are associated with footpoints of giant coronal loops, which connect the polar regions and the following parts of the active complexes. These structures of coronal activity are also pronounced in the soft X-ray maps. However, the whole structure of the giant polar loops is visible in X-rays, and reveals connections to the low-latitude coronal structures. The relationship between the soft X-rays emission and the photospheric magnetic flux obtained from SOHO/MDI and Kitt Peak Solar Observatory has been investigated. It has been found that the relationship depends on the phase of the solar cycle. We discuss the role of the magnetic flux in the formation and evolution of the stable coronal structures during the rising phase of cycle 23.

  3. Correlative imaging of live biological cells with a soft x-ray microscope and a fluorescence microscope

    NASA Astrophysics Data System (ADS)

    Kado, M.; Kishimoto, M.; Tamotsu, S.; Yasuda, K.; Aoyama, M.; Tone, S.; Shinohara, K.

    2016-01-01

    A laser-plasma soft X-ray microscope which is a combination of a highly intense laser-plasma soft X-ray source and a contact microscopy has been developed. We have proposed a correlative imaging method with the laser-plasma soft X-ray microscope and a fluorescence microscope to observe the same biological cells with the both microscopes at the same time. Live hydrated biological cells and cellular organelles have been observed with the correlative imaging method. Using the information of the cellular organelles obtained with the fluorescence microscope, inner structures obtained with the soft X-ray microscope are identified. Since the spatial resolution of the soft X-ray microscope is much higher than that of the fluorescence microscope, fine structures of the cellular organelles of the live biological cells have been visualized with the correlative imaging.

  4. Imaging interfacial micro- and nano-bubbles by scanning transmission soft X-ray microscopy.

    PubMed

    Zhang, Lijuan; Zhao, Binyu; Xue, Lian; Guo, Zhi; Dong, Yaming; Fang, Haiping; Tai, Renzhong; Hu, Jun

    2013-05-01

    Synchrotron-based scanning transmission soft X-ray microscopy (STXM) with nanometer resolution was used to investigate the existence and behavior of interfacial gas nanobubbles confined between two silicon nitride windows. The observed nanobubbles of SF6 and Ne with diameters smaller than 2.5 µm were quite stable. However, larger bubbles became unstable and grew during the soft X-ray imaging, indicating that stable nanobubbles may have a length scale, which is consistent with a previous report using atomic force microscopy [Zhang et al. (2010), Soft Matter, 6, 4515-4519]. Here, it is shown that STXM is a promising technique for studying the aggregation of gases near the solid/water interfaces at the nanometer scale. PMID:23592619

  5. Recent results in capillary discharge soft x-ray laser research

    NASA Astrophysics Data System (ADS)

    Rocca, Jorge J.; Marconi, Mario C.; Wang, Yong; Luther, Bradley M.; Pedacci, Francesco; Grisham, Michael; Vaschenko, Georgiy; Menoni, Carmen S.; Filevich, Jorge; Juha, Libor; Pershin, Yu. P.; Zubarev, E. N.; Voronov, D. L.; Sevryukova, V. A.; Kondratenko, V. V.; Shlyaptsev, Vyacheslav V.; Vinogradov, Alexander; Artioukov, Igor

    2003-12-01

    We report results of the development of capillary discharge driven metal-vapor plasma waveguides for the development of efficient laser-pumped soft x-ray lasers; and of the use of a previously developed capillary discharge Ne-like Ar 46.9 nm laser in study of the interaction of intense soft x-ray laser with materials. The guiding of a laser beam in a dense capillary discharge plasma channel containing a large density of Ag ions is reported. In term of applications we have conducted studies of materials modification and ablation with focalized 46.9 nm laser radiation at fluences between 0.1 and 100 J cm-2. The experiments demonstrated that the combined high repetition rate and high energy per pulse of the capillary discharge laser allows for the first time the processing of large surface areas with intense soft x-ray laser radiation. The damage threshold and damage mechanism of extreme ultraviolet Sc/Si multilayer mirror coatings was studied . Damage threshold fluences of ~ 0.08 J/cm2 were determined for coatings deposited on both borosilicate glass and Si substrates. Scanning and transmission electron microscopy, and small-angle X-ray diffraction techniques revealed the thermal nature of the damage mechanism. These results provide a benchmark for the use of Sc/Si multilayer mirrors in high fluence applications, and for the development of higher damage threshold mirrors. Soft x-ray laser ablation studies were also conducted for silicon and several plastic materials, including PMMA, Polyamide and PTFE.

  6. Ionized Absorbers in Active Galactic Nuclei and Very Steap Soft X-Ray Quasars

    NASA Technical Reports Server (NTRS)

    Fiore, Fabrizio; White, Nicholas (Technical Monitor)

    2000-01-01

    Steep soft X-ray (0.1-2 keV) quasars share several unusual properties: narrow Balmer lines, strong Fe II emission, large and fast X-ray variability, and a rather steep 2-10 keV spectrum. These intriguing objects have been suggested to be the analogues of Galactic black hole candidates in the high, soft state. We present here results from ASCA observations for two of these quasars: NAB 0205 + 024 and PG 1244 + 026. Both objects show similar variations (factor of approximately 2 in 10 ks), despite a factor of approximately 10 difference in the 0.5-10 keV luminosity (7.3 x 10(exp 43) erg/s for PG 1244 + 026 and 6.4 x 10(exp 44) erg/s for NAB 0205 + 024, assuming isotropic emission, H(sub 0) = 50.0 and q(sub 0) = 0.0). The X-ray continuum of the two quasars flattens by 0.5-1 going from the 0.1-2 keV band towards higher energies, strengthening recent results on another half-dozen steep soft X-ray active galactic nuclei. PG 1244 + 026 shows a significant feature in the '1-keV' region, which can be described either as a broad emission line centered at 0.95 keV (quasar frame) or as edge or line absorption at 1.17 (1.22) keV. The line emission could be a result of reflection from a highly ionized accretion disc, in line with the view that steep soft X-ray quasars are emitting close to the Eddington luminosity. Photoelectric edge absorption or resonant line absorption could be produced by gas outflowing at a large velocity (0.3-0.6 c).

  7. 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

  8. A CANDIDATE ACTIVE GALACTIC NUCLEUS WITH A PURE SOFT THERMAL X-RAY SPECTRUM

    SciTech Connect

    Terashima, Yuichi; Kamizasa, Naoya; Awaki, Hisamitsu; Kubota, Aya; Ueda, Yoshihiro

    2012-06-20

    We report the discovery of a candidate active galactic nucleus (AGN), 2XMM J123103.2+110648 at z = 0.13, with an X-ray spectrum represented purely by soft thermal emission reminiscent of Galactic black hole (BH) binaries in the disk-dominated state. This object was found in the second XMM-Newton serendipitous source catalog as a highly variable X-ray source. In three separate observations, its X-ray spectrum can be represented either by a multicolor disk blackbody model with an inner temperature of kT{sub in} Almost-Equal-To 0.16-0.21 keV or a Wien spectrum Comptonized by an optically thick plasma with kT Almost-Equal-To 0.14-0.18 keV. The soft X-ray luminosity in the 0.5-2 keV band is estimated to be (1.6-3.8) Multiplication-Sign 10{sup 42} erg s{sup -1}. Hard emission above {approx}2 keV is not detected. The ratio of the soft to hard emission is the strongest among AGNs observed thus far. Spectra selected in high/low-flux time intervals are examined in order to study spectral variability. In the second observation with the highest signal-to-noise ratio, the low-energy (below 0.7 keV) spectral regime flattens when the flux is high, while the shape of the high-energy part (1-1.7 keV) remains unchanged. This behavior is qualitatively consistent with being caused by strong Comptonization. Both the strong soft excess and spectral change consistent with Comptonization in the X-ray spectrum imply that the Eddington ratio is large, which requires a small BH mass (smaller than {approx}10{sup 5} M{sub Sun }).

  9. 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

  10. Soft X-ray observations of Centaurus X-3 from Copernicus

    NASA Technical Reports Server (NTRS)

    Margon, B.; Mason, K. O.; Hawkins, F. J.; Sanford, P. W.

    1975-01-01

    We have detected soft X-ray emission from Centaurus X-3 in the 0.6-1.9 keV band, using the focusing telescope aboard OAO Copernicus. The flux is compatible with an extrapolation of the harder X-ray spectrum, attenuated by (3-4) times 10 to the 22nd atoms per sq cm of interstellar and/or circumstellar matter. The data are consistent with the distance estimate of 5-10 kpc derived from the spectroscopic modulus of the optical component, and obviate the need to postulate the primary to be an anomalously subluminous hot star. There is currently no compelling evidence that such models must be invoked to explain any of the observed compact X-ray sources.

  11. Gas cell for in situ soft X-ray transmission-absorption spectroscopy of materials

    SciTech Connect

    Drisdell, W. S.; Kortright, J. B.

    2014-07-15

    A simple gas cell design, constructed primarily from commercially available components, enables in situ soft X-ray transmission-absorption spectroscopy of materials in contact with gas at ambient temperature. The cell has a minimum X-ray path length of 1 mm and can hold gas pressures up to ∼300 Torr, and could support higher pressures with simple modifications. The design enables cycling between vacuum and gas environments without interrupting the X-ray beam, and can be fully sealed to allow for measurements of air-sensitive samples. The cell can attach to the downstream port of any appropriate synchrotron beamline, and offers a robust and versatile method for in situ measurements of certain materials. The construction and operation of the cell are discussed, as well as sample preparation and proper spectral analysis, illustrated by examples of spectral measurements. Potential areas for improvement and modification for specialized applications are also mentioned.

  12. The young hard active Sun: soft X-ray irradiation of tryptophan in water solutions

    NASA Astrophysics Data System (ADS)

    Ciaravella, A.; Bongiorno, D.; Cecchi-Pestellini, C.; Testa, M. L.; Indelicato, S.; Barbera, M.; Collura, A.; La Barbera, A.; Mingoia, F.

    2011-01-01

    The X-ray emission of the young Sun was much harder and intense than today and might have played a significant role in the evolution of complex organics in protoplanetary environments. We investigate the effects of soft X-rays on tryptophan molecules in aqueous solutions at room temperature. As results of the irradiation experiments we detect several light species indicative of fragmentation, together with large molecular structures such as tryptophan dipeptide and tripeptide. Complexification is more evident in H2O solution than in D2O, probably due to isotopic effects. The abundances of peptides depend on the irradiation dose and decrease with increasing energy deposition. Radicals such as D, OD, H and OH, induced by the X-ray interaction with solvents, play a major role in determining the final products.

  13. Soft x-ray spectrometer (SXS): the high-resolution cryogenic spectrometer onboard ASTRO-H

    NASA Astrophysics Data System (ADS)

    Mitsuda, Kazuhisa; Kelley, Richard L.; Akamatsu, Hiroki; Bialas, Thomas; Boyce, Kevin R.; Brown, Gregory V.; Canavan, Edgar; Chiao, Meng; Costantini, Elisa; den Herder, Jan-Willem; de Vries, Cor; DiPirro, Michael J.; Eckart, Megan E.; Ezoe, Yuichiro; Fujimoto, Ryuichi; Haas, Daniel; Hoshino, Akio; Ishikawa, Kumi; Ishisaki, Yoshitaka; Iyomoto, Naoko; Kilbourne, Caroline A.; Kimball, Mark; Kitamoto, Shunji; Konami, Saori; Leutenegger, Maurice A.; McCammon, Dan; Miko, Joseph; Mitsuishi, Ikuyuki; Murakami, Hiroshi; Murakami, Masahide; Noda, Hirofumi; Ogawa, Mina; Ohashi, Takaya; Okamoto, Atsushi; Ota, Naomi; Paltani, Stéphane; Porter, F. Scott; Sato, Kosuke; Sato, Yoichi; Sawada, Makoto; Seta, Hiromi; Shinozaki, Keisuke; Shirron, Peter J.; Sneiderman, Gary A.; Sugita, Hiroyuki; Szymkowiak, Andrew; Takei, Yoh; Tamagawa, Toru; Tashiro, Makoto S.; Terada, Yukikatsu; Tsujimoto, Masahiro; Yamada, Shinya; Yamasaki, Noriko Y.

    2014-07-01

    We present the development status of the Soft X-ray Spectrometer (SXS) onboard the ASTRO-H mission. The SXS provides the capability of high energy-resolution X-ray spectroscopy of a FWHM energy resolution of < 7eV in the energy range of 0.3 - 10 keV. It utilizes an X-ray micorcalorimeter array operated at 50 mK. The SXS microcalorimeter subsystem is being developed in an EM-FM approach. The EM SXS cryostat was developed and fully tested and, although the design was generally confirmed, several anomalies and problems were found. Among them is the interference of the detector with the micro-vibrations from the mechanical coolers, which is the most difficult one to solve. We have pursued three different countermeasures and two of them seem to be effective. So far we have obtained energy resolutions satisfying the requirement with the FM cryostat.

  14. Time-varying oscillations in the solar soft X-ray flux as observed from Skylab

    NASA Technical Reports Server (NTRS)

    Teuber, D. L.; Wilson, R. M.; Henze, W., Jr.

    1978-01-01

    Observations obtained by the Skylab/Apollo telescope S-056 X-ray experiment were used to study the time-varying oscillations in the solar soft X-ray flux during a flare. The observations consisted of count rates measured every 2.5 s by sealed, gas-filled counters operating over the 2.5-7.25-A and 6.1-20.0-A wavelength ranges. The power spectra for two other intervals were computed to determine whether the observed oscillations were flare-associated or instrumental in origin. The data indicate that the oscillations in the flare-associated X-ray flux are caused by waves which are generated during the flare and which periodically increase the electron density. No oscillations were observed during quiet periods.

  15. Superconducting Detector System for High-Resolution Energy-Dispersive Soft X-Ray Spectroscopy

    SciTech Connect

    Friedrich, S; Niedermayr, T; Drury, O; Funk, T; Frank, M; Labov, S E; Cramer, S

    2001-02-21

    Synchrotron-based soft x-ray spectroscopy is often limited by detector performance. Grating spectrometers have the resolution, but lack the efficiency for the analysis of dilute samples. Semiconducting Si(Li) or Ge detectors are efficient, but often lack the resolution to separate weak signals from strong nearby lines in multi-element samples. Superconducting tunnel junctions (STJs) operated at temperatures below 1 K can be used as high-resolution high-efficiency x-ray detectors. They combine high energy resolution around 10 eV FWHM with the broad band efficiency of energy-dispersive detectors. We have designed a two-stage adiabatic demagnetization refrigerator (ADR) to operate STJ detectors in x-ray fluorescence measurements at beam line 4 of the ALS. We demonstrate the capabilities of such a detector system for fluorescence analysis of dilute metal sites in proteins and inorganic model compounds.

  16. Soft X-ray transients in quiescence - Observations of AQL X-1 and CEN X-4

    NASA Astrophysics Data System (ADS)

    van Paradijs, J.; Verbunt, F.; Shafer, R. A.; Arnaud, K. A.

    1987-08-01

    The authors observed the soft X-ray transients Aql X-1 and Cen X-4 during quiescence with EXOSAT. For Aql X-1 they obtain a 3σ upper limit to the X-ray luminosity Lx (in the energy range between 0.5 and 4.5 keV) of <3.0×1033erg s-1, Cen X-4 was detected at Lx (0.5 - 4.5 keV) ≅ 1.5 to 4.2×1033erg s-1. An optical spectrum of Cen X-4 obtained two years after its 1979 outburst shows a K3 V continuum with Balmer emission lines. Combining their EXOSAT observations with a previous EINSTEIN detection the authors argue that the X-ray luminosity of Cen X-4 is due to continued accretion, and not to thermal radiation of a cooling neutron star.

  17. SolpeX: the soft X-ray flare polarimeter-spectrometer for the ISS

    NASA Astrophysics Data System (ADS)

    Sylwester, Janusz; Płocieniak, Stefan; Bakała, Jarosław; Szaforz, Żaneta; Stȩślicki, Marek; Ścisłowski, Daniel; Kowaliński, Mirosław; Podgórski, Piotr; Hernandez, Jose; Shestov, Sergey

    2015-10-01

    We present the innovative soft X-ray spectro-polarimeter, SolpeX. This instrument consists of three functionally independent blocks. They are to be included into the Russian instrument KORTES, to be mounted onboard the ISS. The three SolpeX units are: a simple pin-hole X-ray spectral imager, a polarimeter, and a fast-rotating drum multiple-flat-crystal Bragg spectrometer. Such a combination of measuring blocks will offer a new opportunity to reliably measure possible X-ray polarization and spectra of solar flares, in particular during the impulsive phase. Polarized Bremsstrahlung and line emission due to the presence of directed particle beams will be detected, and measurements of the velocities of evaporated hot plasma will be made. In this paper we discuss the details of the construction of the SolpeX units. The delivery of KORTES with SolpeX to the ISS is expected to happen in 2017/2018.

  18. Influence of the soft X-ray plasma focus radiation on live microorganisms

    NASA Astrophysics Data System (ADS)

    Zapryanov, S.; Goltsev, V.; Galutsov, B.; Gelev, M.; Blagoev, A.

    2012-04-01

    A 3 kJ plasma focus device was used to study the influence of the soft X-ray on live microorganisms. When Saccharomyces cerevisiae - (yeast) was treated with a dose of 65 mSv of the X-ray radiation (14 shots), no difference in the fertility activity between the control probe and the sample was observed. Also no change in the survival enzyme activity was found after irradiation through a 100 μm Al foil of another type of yeast - Kluyveromyces marxiamus. The irradiation of the Chlamydomonas reinhardtii samples by the PF-X-ray emission through 20 μm Al foil with a dose of 11 mSv produces a considerable change of the photosynthesis parameters. This result is similar to the results of previous studies with plasma focus radiation where strong effects were derived with low doses but with a high dose power.

  19. Cooling system for the soft x-ray spectrometer (SXS) onboard ASTRO-H

    NASA Astrophysics Data System (ADS)

    Fujimoto, Ryuichi; Mitsuda, Kazuhisa; Yamasaki, Noriko; Takei, Yoh; Tsujimoto, Masahiro; Sugita, Hiroyuki; Sato, Yoichi; Shinozaki, Keisuke; Okamoto, Atsushi; Ohashi, Takaya; Ishisaki, Yoshitaka; Ezoe, Yuichiro; Ishikawa, Kumi; Murakami, Masahide; Kitamoto, Shunji; Murakami, Hiroshi; Tamagawa, Toru; Kawaharada, Madoka; Yamaguchi, Hiroya; Sato, Kosuke; Hoshino, Akio; Kanao, Kenichi; Yoshida, Seiji; Miyaoka, Mikio; Dipirro, Michael; Shirron, Peter; Sneiderman, Gary; Kelley, Richard L.; Porter, F. Scott; Kilbourne, Caroline A.; Crow, John; Mattern, Andrea; Kashani, Ali; McCammon, Dan

    2010-07-01

    The Soft X-ray Spectrometer (SXS) is a cryogenic high resolution X-ray spectrometer onboard the X-ray astronomy satellite ASTRO-H. The detector array is cooled down to 50 mK using a 3-stage adiabatic demagnetization refrigerator (ADR). The cooling chain from room temperature to the ADR heat-sink is composed of superfluid liquid He, a 4He Joule-Thomson cryocooler, and 2-stage Stirling cryocoolers. It is designed to keep 30 L of liquid He for more than 3 years in the nominal case. It is also designed with redundant subsystems throughout from room temperature to the ADR heat-sink, to alleviate failure of a single cryocooler or loss of liquid He.

  20. Octupole Magnet For Soft X Ray Magnetic Dichroism Experiments: Design and Performance

    SciTech Connect

    Arenholz, Elke; Prestemon, Soren O.

    2004-05-12

    An octupole magnet endstation for soft x ray magnetic dichroism measurements has been developed at the Advanced Light Source. The system consists of an eight pole electromagnet that surrounds a small vacuum chamber. The magnet provides fields up to 0.9 T that can be applied in any direction relative to the incoming x ray beam. High precision magnetic circular and linear dichroism spectra can be obtained reversing the magnetic field for each photon energy in an energy scan. Moreover, the field dependence of all components of the magnetization vector can be studied in detail by choosing various angles of x ray incidence while keeping the relative orientation of magnetic field and sample fixed.

  1. Octupole magnet for soft X ray magnetic dichroism experiments: Design and performance

    SciTech Connect

    Arenholz, Elke; Prestemon, Soren O.

    2003-08-24

    An octupole magnet endstation for soft x-ray magnetic dichroism measurements has been developed at the Advanced Light Source. The system consists of an eight pole electromagnet that surrounds a small vacuum chamber. The magnet provides fields up to 0.9 T that can be applied in any direction relative to the incoming x-ray beam. High precision magnetic circular and linear dichroism spectra can be obtained reversing the magnetic field for each photon energy in an energy scan. Moreover, the field dependence of all components of the magnetization vector can be studied in detail by choosing various angles of x-ray incidence while keeping the relative orientation of magnetic field and sample fixed.

  2. Fabrication of compound refractive lens using soft and deep X-ray lithography beamline on Indus-2

    SciTech Connect

    Dhamgaye, V. P.; Lodha, G. S.

    2012-06-05

    X-ray compound refractive lenses (CRL) have been fabricated using Soft and Deep X-ray lithography (SDXRL) beamline on Indus-2. Upto 50 parabolic lenses are fabricated in PMMA using 1X X-ray mask. The mask contains of 20 micron thick gold absorbing pattern on polyimide membrane. The lens fabrication is done by exposing 500 {mu}m thick PMMA sheets to 5-12keV X-rays from Indus-2. The fabricated CRL will be suitable for generating focused X-ray beam of Indus-2 bending magnet source.

  3. Quantum efficiency of Si Hybrid CMOS detectors in the soft X-ray band

    NASA Astrophysics Data System (ADS)

    Prieskorn, Zachary; Bongiorno, Stephen; Burrows, David; Falcone, Abraham; Griffith, Christopher; Nikoleyczik, Jonathan; Wells, Mark; PSU X-ray Instrumentation Group Team

    2015-04-01

    X-ray sensitive Si Hybrid CMOS detectors (HCDs) will potentially replace X-ray CCDs in the focal planes of future X-ray observatories. HCDs improve on the performance of CCDs in numerous areas: faster read out time, windowed read out mode, less susceptibility to radiation & micrometeoroid damage, and lower power consumption. Understanding the detector quantum efficiency (QE) is critical for estimating the sensitivity of an X-ray instrument. We report on the QE for multiple energies in the soft X-ray band of four HCDs based on the Teledyne Imaging Sensors HyViSITM detectors. These detectors have Al optical blocking filters deposited directly on the Si substrate; these filters vary in thickness from 180 - 1000 Å. We estimate the QE with a 1D slab absorption model and find good agreement between the model and our results across an energy range from 0.677 - 8.05 keV. This work was supported by NASA Grants NNG05WC10G, NNX08AI64G, and NNX11AF98G.

  4. Soft x-ray images of the laser entrance hole of ignition hohlraums.

    PubMed

    Schneider, M B; Meezan, N B; Alvarez, S S; Alameda, J; Baker, S; Bell, P M; Bradley, D K; Callahan, D A; Celeste, J R; Dewald, E L; Dixit, S N; Döppner, T; Eder, D C; Edwards, M J; Fernandez-Perea, M; Gullikson, E; Haugh, M J; Hau-Riege, S; Hsing, W; Izumi, N; Jones, O S; Kalantar, D H; Kilkenny, J D; Kline, J L; Kyrala, G A; Landen, O L; London, R A; MacGowan, B J; MacKinnon, A J; McCarville, T J; Milovich, J L; Mirkarimi, P; Moody, J D; Moore, A S; Myers, M D; Palma, E A; Palmer, N; Pivovaroff, M J; Ralph, J E; Robinson, J; Soufli, R; Suter, L J; Teruya, A T; Thomas, C A; Town, R P; Vernon, S P; Widmann, K; Young, B K

    2012-10-01

    Hohlraums are employed at the national ignition facility to convert laser energy into a thermal x-radiation drive, which implodes a fusion capsule, thus compressing the fuel. The x-radiation drive is measured with a low spectral resolution, time-resolved x-ray spectrometer, which views the region around the hohlraum's laser entrance hole. This measurement has no spatial resolution. To convert this to the drive inside the hohlraum, the size of the hohlraum's opening ("clear aperture") and fraction of the measured x-radiation, which comes from this opening, must be known. The size of the clear aperture is measured with the time integrated static x-ray imager (SXI). A soft x-ray imaging channel has been added to the SXI to measure the fraction of x-radiation emitted from inside the clear aperture. A multilayer mirror plus filter selects an x-ray band centered at 870 eV, near the peak of the x-ray spectrum of a 300 eV blackbody. Results from this channel and corrections to the x-radiation drive are discussed. PMID:23127032

  5. Correlative analysis of hard and soft x ray observations of solar flares

    NASA Technical Reports Server (NTRS)

    Zarro, Dominic M.

    1994-01-01

    We have developed a promising new technique for jointly analyzing BATSE hard X-ray observations of solar flares with simultaneous soft X-ray observations. The technique is based upon a model in which electric currents and associated electric fields are responsible for the respective heating and particle acceleration that occur in solar flares. A useful by-product of this technique is the strength and evolution of the coronal electric field. The latter permits one to derive important flare parameters such as the current density, the number of current filaments composing the loop, and ultimately the hard X-ray spectrum produced by the runaway electrons. We are continuing to explore the technique by applying it to additional flares for which we have joint BATSE/Yohkoh observations. A central assumption of our analysis is the constant of proportionality alpha relating the hard X-ray flux above 50 keV and the rate of electron acceleration. For a thick-target model of hard X-ray production, it can be shown that cv is in fact related to the spectral index and low-energy cutoff of precipitating electrons. The next step in our analysis is to place observational constraints on the latter parameters using the joint BATSE/Yohkoh data.

  6. Yeast cell metabolism investigated by CO{_2} production and soft X-ray irradiation

    NASA Astrophysics Data System (ADS)

    Masini, A.; Batani, D.; Previdi, F.; Milani, M.; Pozzi, A.; Turcu, E.; Huntington, S.; Takeyasu, H.

    1999-01-01

    Results obtained using a new technique for studying cell metabolism are presented. The technique, consisting in CO2 production monitoring, has been applied to Saccharomyces cerevisiae yeast cells. Also the cells were irradiated using the soft X-ray laser-plasma source at Rutherford Appleton Laboratory with the aim of producing a damage of metabolic processes at the wall level, responsible for fermentation, without great interference with respiration, taking place in mitochondria, and DNA activity. The source was calibrated with PIN diodes and X-ray spectrometers and used Teflon stripes as target, emitting X-rays at about 0.9 keV, with a very low penetration in biological material. X-ray doses delivered to the different cell compartments were calculated following a Lambert-Bouguet-Beer law. Immediately after irradiation, the damage to metabolic activity was measured again by monitoring CO2 production. Results showed a general reduction in gas production by irradiated samples, together with non-linear and non-monotone response to dose. There was also evidence of oscillations in cell metabolic activity and of X-ray induced changes in oscillation frequency.

  7. Soft x-ray images of the Laser Entrance Hole of NIC Hohlraums (paper, HTPD2012)

    SciTech Connect

    Schneider, M B; Meezan, N B

    2012-04-30

    Hohlraums at the National Ignition Facility convert laser energy into a thermal x-radiation drive, which implodes the capsule, thus compressing the fuel. The x-radiation drive is measured with a low resolution, time-resolved x-ray spectrometer that views the hohlraum's laser entrance hole (LEH) at 37{sup o} to the hohlraum axis. This measurement has no spatial resolution. To convert this to the drive inside the hohlraum, the area and fraction of the measured x-radiation which comes from the region inside the hohlraum must be known. The size of the LEH is measured with the time integrated Static X-ray Imager (SXI) which view the LEH at 18{sup o} to the hohlraum axis. A soft x-ray image has been added to the SXI to measure the fraction of x-radiation inside the LEH's Clear Aperture in order to correct the measured radiation. A multilayer mirror plus filter selects an x-ray band centered at 870 eV, near the x-ray energy peak of a 300 eV blackbody. Results from this channel and corrections to the x-radiation drive are discussed.

  8. Wavelength dispersing devices for soft and ultrasoft x-ray spectrometers

    SciTech Connect

    Arai, Tomoya; Ryon, R.W.; Shoji, Takashi

    1984-01-01

    Monochromatization combining total reflection by a selected mirror and an appropriate filter offered an alternative approach in order to increase measurable intensity with reasonable spectral resolution. Recently, the use of synthetic multilayers, which are prepared by sputter/evaporation techniques, has been introduced for the detection of soft and ultrasoft x-rays. Studies on the use of these new wavelength dispersing devices have been conducted and it has been found that the reflectivity of these devices is very high compared with single crystals and soap multilayers and that their resolving power is fairly good. This report makes comparisons regarding efficiency of reflection, resolving power and x-ray analytical problems for practical applications among long spacing single crystals, soap multilayers, total reflection combined with a selected mirror and filtering and synthetic multilayers. The x-ray analytical capablities are shown based upon a standard x-ray fluorescence spectrometer equipped with a sealed-off x-ray tube and a gas flow proportional counter with thin film detector window.

  9. Soft-x-ray fluorescence study of buried silicides in antiferromagnetically coupled Fe/Si multilayers

    SciTech Connect

    Carlisle, J.A.; Chaiken, A.; Michel, R.P.

    1997-04-01

    Multilayer films made by alternate deposition of two materials play an important role in electronic and optical devices such as quantum-well lasers and x-ray mirrors. In addition, novel phenomena like giant magnetoresistance and dimensional crossover in superconductors have emerged from studies of multilayers. While sophisticated x-ray techniques are widely used to study the morphology of multilayer films, progress in studying the electronic structure has been slower. The short mean-free path of low-energy electrons severely limits the usefulness of photoemission and related electron free path of low-energy electrons severely limit spectroscopies for multilayer studies. Soft x-ray fluorescence (SXF) is a bulk-sensitive photon-in, photon-out method to study valence band electronic states. Near-edge x-ray absorption fine-structure spectroscopy (NEXAFS) measured with partial photon yield can give complementary bulk-sensitive information about unoccupied states. Both these methods are element-specific since the incident x-ray photons excite electrons from core levels. By combining NEXAFS and SXF measurements on buried layers in multilayers and comparing these spectra to data on appropriate reference compounds, it is possible to obtain a detailed picture of the electronic structure. Results are presented for a study of a Fe/Si multilayer system.

  10. Time Resolved 2D X-Ray Densitometry of a Ventilated Partial Cavity Closure

    NASA Astrophysics Data System (ADS)

    Makiharju, Simo; Ceccio, Steven

    2011-11-01

    A time resolved x-ray densitometry system was developed to measure the spatial distribution of void fraction for nominally two-dimensional flows. The system can image a region of (15 cm)2 at a frame rate of up to 4000 fps. The source was a rotating anode type normally used for cineradiography and angiography. Supplied by a 65 kW high frequency generator with a high speed starter, it could be operated at up to 433 mA at 150 kV. The imager subsystem comprised of a high speed camera coupled with a high resolution image intensifier. The range of measured void fraction can be changed to span a desired range yielding an uncertainty on the order of 1% of the measurement range. The system is used to examine the void fraction field in the closure region of a ventilated partial cavity behind a backward facing step. The cavity has Reynolds number of O(105) based on the cavity length, and a non-dimensional gas flux of Q* = 0.0048. The bubbly flow created in the cavity wake is examined using the x-ray densitometry system, duel fiber optical probes, and high speed cinematography. The local void fraction and bubble size distributions in the cavity wake are determined, and the measurements methods are compared. The research was sponsored by ONR under grant N00014-08-1-0215, program manager Dr. L. Patrick Purtell.

  11. 2D-Omnidirectional Hard-X-Ray Scattering Sensitivity in a Single Shot.

    PubMed

    Kagias, Matias; Wang, Zhentian; Villanueva-Perez, Pablo; Jefimovs, Konstantins; Stampanoni, Marco

    2016-03-01

    X-ray scattering imaging can provide complementary information to conventional absorption based radiographic imaging about the unresolved microstructures of a sample. The scattering signal can be accessed with various methods based on coherent illumination, which span from self-imaging to speckle scanning. The directional sensitivity of the existing real space imaging methods is limited to a few directions on the imaging plane and requires scanning of the optical components, or the rotation of either the sample or the imaging setup, in order to cover the full range of possible scattering directions. In this Letter the authors propose a new method that allows the simultaneous acquisition of scattering images in all possible directions in a single shot. This is achieved by a specialized phase grating and a detector with sufficient spatial resolution to record the generated interference fringe. The structural length scale sensitivity of the system can be tuned by varying its geometry for a fixed grating design. Taking into account ongoing developments in the field of compact x-ray sources that allow high brightness and sufficient spatial coherence, the applicability of omnidirectional scattering imaging in industrial and medical settings is boosted significantly. PMID:26991177

  12. 2D x-ray imaging spectroscopic diagnostics using convex bent crystal

    NASA Astrophysics Data System (ADS)

    Papp, Daniel; Presura, Radu; Wallace, Matt; Largent, Billy; Haque, Showera; Arias, Angel; Khanal, Vijay; Ivanov, Vladimir

    2013-10-01

    A new 2-dimensional time-integrated x-ray spectroscopic diagnostics technique was developed to create multi-monochromatic images of high-energy density Al plasmas. 2-dimensional is an advanced spectroscopic tool, providing a way to determine the spatial dependence of plasma temperature and density (Te and ne) in hot plasmas. The new technique uses the strong source broadening of convex cylindrically bent KAP crystal spectrometers, which contains spatial information along the dispersive direction. The perpendicular direction is imaged using a slit. The spatial resolution of the method is improved by the deconvolution of the source broadened line profiles from the lineshapes (recorded by the convex crystal spectrometer) with lineshapes of minimum instrumental broadening. The latter spectra were recorded with a concave cylindrically bent KAP crystal spectrometer, based on the Johann geometry. Spectroscopic model of the plasma x-ray emission was developed using the PrismSPECT code. The identification of suitable spectral features allows deriving Te and ne from line intensities. We applied this model to get temperature and density distribution maps for wire array z-pinch plasmas. Work supported by the DOE/NNSA under grant DE-NA0001834 and Cooperative Agreement DE-FC52-06NA27616.

  13. 2D-Omnidirectional Hard-X-Ray Scattering Sensitivity in a Single Shot

    NASA Astrophysics Data System (ADS)

    Kagias, Matias; Wang, Zhentian; Villanueva-Perez, Pablo; Jefimovs, Konstantins; Stampanoni, Marco

    2016-03-01

    X-ray scattering imaging can provide complementary information to conventional absorption based radiographic imaging about the unresolved microstructures of a sample. The scattering signal can be accessed with various methods based on coherent illumination, which span from self-imaging to speckle scanning. The directional sensitivity of the existing real space imaging methods is limited to a few directions on the imaging plane and requires scanning of the optical components, or the rotation of either the sample or the imaging setup, in order to cover the full range of possible scattering directions. In this Letter the authors propose a new method that allows the simultaneous acquisition of scattering images in all possible directions in a single shot. This is achieved by a specialized phase grating and a detector with sufficient spatial resolution to record the generated interference fringe. The structural length scale sensitivity of the system can be tuned by varying its geometry for a fixed grating design. Taking into account ongoing developments in the field of compact x-ray sources that allow high brightness and sufficient spatial coherence, the applicability of omnidirectional scattering imaging in industrial and medical settings is boosted significantly.

  14. Installation of soft X-ray array diagnostics and its application to tomography reconstruction using synthetic KSTAR X-ray images.

    PubMed

    Lee, Seung Hun; Jang, Juhyeok; Hong, Joohwan; Pacella, D; Romano, A; Gabellieri, L; Jang, Siwon; Kim, Junghee; Choe, Wonho

    2014-11-01

    Four-array system of soft X-ray diagnostics was installed on KSTAR tokamak. Each array has 32 viewing chords of two photo-diode array detectors with spatial resolution of 2 cm. To estimate signals from the soft X-ray radiation power, typical ne, Te, and argon impurity line radiation profiles in KSTAR are chosen. The photo-diodes were absolutely calibrated as a function of the incident photon energy in 2-40 keV range with a portable X-ray tube. Two-dimensional Te image properties by multi-energy method were simulated and visualized with six combinations of beryllium filter sets within the dynamic range of signal ratio. PMID:25430392

  15. Installation of soft X-ray array diagnostics and its application to tomography reconstruction using synthetic KSTAR X-ray images

    SciTech Connect

    Lee, Seung Hun; Jang, Juhyeok; Hong, Joohwan; Jang, Siwon; Choe, Wonho; Pacella, D.; Romano, A.; Gabellieri, L.; Kim, Junghee

    2014-11-15

    Four-array system of soft X-ray diagnostics was installed on KSTAR tokamak. Each array has 32 viewing chords of two photo-diode array detectors with spatial resolution of 2 cm. To estimate signals from the soft X-ray radiation power, typical n{sub e}, T{sub e}, and argon impurity line radiation profiles in KSTAR are chosen. The photo-diodes were absolutely calibrated as a function of the incident photon energy in 2–40 keV range with a portable X-ray tube. Two-dimensional T{sub e} image properties by multi-energy method were simulated and visualized with six combinations of beryllium filter sets within the dynamic range of signal ratio.

  16. SOFT TIME LAGS IN THE X-RAY EMISSION OF Mrk 1040

    SciTech Connect

    Tripathi, Shruti; Rastogi, Shantanu; Misra, Ranjeev; Dewangan, Gulab E-mail: rmisra@iucaa.ernet.in

    2011-08-01

    Temporal analysis of X-ray binaries and active galactic nuclei (AGNs) have shown that hard X-rays react to variation of soft ones after a time delay. The opposite trend, or soft lag, has only been seen in a few rare quasi-periodic oscillations in X-ray binaries and recently for the AGN 1H 0707-495, on short timescales of {approx}10{sup 3} s. Here, we report analysis of an XMM-Newton observation of Mrk 1040, which reveals that on the dominant variability timescale of {approx}10{sup 4} s, the source seems to exhibit soft lags. If the lags are frequency independent, they could be due to reverberation effects of a relativistically blurred reflection component responding to a varying continuum. Alternatively, they could be due to Comptonization delays in the case when high-energy photons impinge back on the soft photon source. Both models can be verified and their parameters tightly constrained, because they will need to predict the photon spectrum, rms variability, and time lag as a function of energy. A successful application of either model will provide unprecedented information on the radiative process, geometry, and more importantly the size of the system, which in turn may provide a stringent test of strong general relativistic effects.

  17. The Soft X-Ray Emission in a Large Sample of Galaxy Clusters with ROSAT PSPC

    NASA Technical Reports Server (NTRS)

    Bonamente, Massimiliano; Lieu, Richard; Joy, Marshall K.; Nevalainen, Jukka H.; Six, N. Frank (Technical Monitor)

    2002-01-01

    The study of soft X-ray emission of 38 X-ray selected galaxy clusters observed by ROSAT PSPC indicates that the soft excess phenomenon may be a common occurrence in galaxy clusters. Excess soft X-ray radiation, above the contribution from the hot intra-cluster medium, is evident in a large fraction of sources, and is clearly detected with large statistical significance in the deepest observations. The investigation relies on new, high resolution 21 cm HI observations. The sample selection also features analysis of infrared images, to further ensure reliability of results with respect to the characteristics of Galactic absorption. The possibility of background or calibration effects as cause of the excess emission is likewise investigated; a detailed analysis of the distribution of the excess emission with respect to detector position and Galactic HI column density shows that the excess emission is a genuine celestial phenomenon. We find evidence for a preferential distribution of the soft excess emission at distances larger than approx. 150-200 kpc from the centers of clusters; this behavior may be naturally explained in the context of a non-thermal Inverse-Compton scenario. Alternatively, we propose that the phenomenon maybe caused by thermal emission of very large-scale 'warm' filaments seen in recent hydrodynamic simulations. This new interpretation relieves the very demanding requirements of either the traditional intra-cluster 'warm' gas and the non-thermal scenarios. We also investigate the possibility of the soft excess originating from unresolved, X-ray faint cluster galaxies.

  18. 3D nanoscale imaging of biological samples with laboratory-based soft X-ray sources

    NASA Astrophysics Data System (ADS)

    Dehlinger, Aurélie; Blechschmidt, Anne; Grötzsch, Daniel; Jung, Robert; Kanngießer, Birgit; Seim, Christian; Stiel, Holger

    2015-09-01

    In microscopy, where the theoretical resolution limit depends on the wavelength of the probing light, radiation in the soft X-ray regime can be used to analyze samples that cannot be resolved with visible light microscopes. In the case of soft X-ray microscopy in the water-window, the energy range of the radiation lies between the absorption edges of carbon (at 284 eV, 4.36 nm) and oxygen (543 eV, 2.34 nm). As a result, carbon-based structures, such as biological samples, posses a strong absorption, whereas e.g. water is more transparent to this radiation. Microscopy in the water-window, therefore, allows the structural investigation of aqueous samples with resolutions of a few tens of nanometers and a penetration depth of up to 10μm. The development of highly brilliant laser-produced plasma-sources has enabled the transfer of Xray microscopy, that was formerly bound to synchrotron sources, to the laboratory, which opens the access of this method to a broader scientific community. The Laboratory Transmission X-ray Microscope at the Berlin Laboratory for innovative X-ray technologies (BLiX) runs with a laser produced nitrogen plasma that emits radiation in the soft X-ray regime. The mentioned high penetration depth can be exploited to analyze biological samples in their natural state and with several projection angles. The obtained tomogram is the key to a more precise and global analysis of samples originating from various fields of life science.

  19. Spectrally-resolved Soft X-ray Observations and the Temperature Structure of the Solar Corona

    NASA Astrophysics Data System (ADS)

    Caspi, Amir; Warren, Harry; McTiernan, James; Woods, Thomas N.

    2015-04-01

    Solar X-ray observations provide important diagnostics of plasma heating and particle acceleration, during solar flares and quiescent periods. How the corona is heated to its ~1-3 MK nominal temperature remains one of the fundamental unanswered questions of solar physics; heating of plasma to tens of MK during solar flares -- particularly to the hottest observed temperatures of up to ~50 MK -- is also still poorly understood. Soft X-ray emission (~0.1-10 keV; or ~0.1-10 nm) is particularly sensitive to hot coronal plasma and serves as a probe of the thermal processes driving coronal plasma heating. Spectrally- and temporally-resolved measurements are crucial for understanding these energetic processes, but there have historically been very few such observations. We present new solar soft X-ray spectra from the Amptek X123-SDD, measuring quiescent solar X-ray emission from ~0.5 to ~30 keV with ~0.15 keV FWHM resolution from two SDO/EVE calibration sounding rocket underflights in 2012 and 2013. Combined with observations from RHESSI, GOES/XRS, SDO/EVE, and SDO/AIA, the temperature distribution derived from these data suggest significant hot (5-10 MK) emission from active regions, and the 2013 spectra suggest a low-FIP enhancement of only ~1.6 relative to the photosphere, 40% of the usually-observed value from quiescent coronal plasma. We explore the implications of these findings on coronal heating. We discuss future missions for spectrally-resolved soft X-ray observations using the X123-SDD, including the upcoming MinXSS 3U CubeSat using the X123-SDD and scheduled for deployment in mid-2015, and the CubIXSS 6U CubeSat mission concept.

  20. Resonant Soft X-Ray Contrast Variation Methods as Composition-Specific Probes of Thin Polymer Film Structure

    SciTech Connect

    Welch, Cynthia; Welch, Cynthia F.; Hjelm, Rex P.; Mang, Joseph T.; Hawley, Marilyn E.; Wrobleski, Debra A.; Orler, E. Bruce; Kortright, Jeffrey B

    2008-04-04

    We have developed complementary soft x-ray scattering and reflectometry techniques that allow for the morphological analysis of thin polymer films without resorting to chemical modification or isotopic 2 labeling. With these techniques, we achieve significant, x-ray energy-dependent contrast between carbon atoms in different chemical environments using soft x-ray resonance at the carbon edge. Because carbon-containing samples absorb strongly in this region, the scattering length density depends on both the real and imaginary parts of the atomic scattering factors. Using a model polymer film of poly(styrene-b-methyl methacrylate), we show that the soft x-ray reflectivity data is much more sensitive to these atomic scattering factors than the soft x-ray scattering data. Nevertheless, fits to both types of data yield useful morphological details on the polymer?slamellar structure that are consistent with each other and with literature values.

  1. 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.

  2. Soft X-Ray Spectroscopy of the Cygnus Loop Supernova Remnant

    NASA Astrophysics Data System (ADS)

    McEntaffer, R. L.; Cash, W.

    2008-06-01

    The Cygnus X-Ray Emission Spectroscopic Survey (CyXESS) sounding rocket payload was launched from White Sands Missile Range on 2006 November 20 and obtained a high-resolution spectrum of the Cygnus Loop supernova remnant in the soft X-ray. The novel X-ray spectrograph incorporated a wire-grid collimator feeding an array of gratings in the extreme off-plane mount that ultimately dispersed the spectrum onto gaseous electron multiplier (GEM) detectors. This instrument recorded 65 s of usable data between 43 and 49.5 Å in two prominent features. The first feature near 45 Å is dominated by the He-like triplet of O VII in second order with contributions from Mg X and Si IX-Si XII in first order, while the second feature near 47.5 Å is first-order S IX and S X. Fits to the spectra give an equilibrium plasma at log (T) = 6.2 (kTe = 0.14 keV) and near cosmic abundances. This is consistent with previous observations, which demonstrated that the soft X-ray emission from the Cygnus Loop is dominated by interactions between the initial blast wave and the walls of a precursor-formed cavity surrounding the Cygnus Loop and that this interaction can be described using equilibrium conditions.

  3. 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.

  4. 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

  5. Dante soft x-ray power diagnostic for National Ignition Facility

    SciTech Connect

    Dewald, E.L.; Campbell, K.M.; Turner, R.E.; Holder, J.P.; Landen, O.L.; Glenzer, S.H.; Kauffman, R.L.; Suter, L.J.; Landon, M.; Rhodes, M.; Lee, D.

    2004-10-01

    Soft x-ray power diagnostics are essential for measuring the total x-ray flux, radiation temperature, conversion efficiency, and albedo that define the energetics in indirect and direct drive, as well as other types of high temperature laser plasma experiments. A key diagnostic for absolute radiation flux and radiation temperature in hohlraum experiments is the Dante broadband soft x-ray spectrometer. For the extended range of x-ray fluxes predicted for National Ignition Facility (NIF) compared to Omega or Nova hohlraums, the Dante spectrometer for NIF will include more high energy (<2 keV) edge filter band-pass channels and access to an increased dynamic range using grids and signal division. This will allow measurements of radiation fluxes of between 0.01 to 100 TW/sr, for hohlraum radiation temperatures between 50 eV and 1 keV. The NIF Dante will include a central four-channel imaging line-of-sight to verify the source size, alignment as well as checking for any radiation contributions from unconverted laser light plasmas.

  6. Analysis of neon soft x-ray spectra from short-pulse laser-produced plasmas

    SciTech Connect

    Abare, A.C.; Keane, C.J.; Crane, J.K.; DaSilva, L.B.; Lee, R.W.; Perry, M.D.; Falcone, R.W.

    1993-04-01

    We report preliminary results from the analysis of streaked soft x-ray neon spectra obtained from the interaction of a picosecond Nd:glass laser with a gas jet target. In these experiments streaked spectra show prompt harmonic emission followed by longer time duration soft x-ray line emission. The majority of the line emission observed was found to originate from Li- and Be-like Ne and the major transitions in the observed spectra have been identified. Li-like emission lines were observed to decay faster in time than Be-like transitions, suggesting that recombination is taking place. Line ratios of n=4-2 and n=3-2 transitions supported the view that these lines were optically thin and thick, respectively. The time history of Li-like Ne 2p-4d and 2p-3d lines is in good agreement with a simple adiabatic expansion model coupled to a time dependent collisional-radiative code. Further x-ray spectroscopic analysis is underway which is aimed at diagnosing plasma conditions and assessing the potential of this recombining neon plasma as a quasi-steady-state recombination x-ray laser medium.

  7. Discovery of an Extraordinary Luminous And Soft X-ray Transient MAXI J0158-744

    NASA Astrophysics Data System (ADS)

    Morii, Mikio; Tomida, Hiroshi; Kimura, Masaki; Suwa, Fumitoshi; Negoro, Hitoshi; Serino, Motoko; Kennea, Jamie A.; Page, Kim L.; Curran, Peter A.; Walter, Frederick M.; Kuin, N. Paul. M.; Pritchard, Tyler; Nakahira, Satoshi; Hiroi, Kazuo; Usui, Ryuichi; Kawai, Nobuyuki; Osborne, Julian P.; Mihara, Tatehiro; Burrows, David N.; Gehrels, Neil; Kohama, Mitsuhiro; Matsuoka, Masaru; Nakajima, Motoki; Roming, Peter W. A.; Sugimori, Kousuke; Sugizaki, Mutsumi; Tsuboi, Yohko; Tsunemi, Hiroshi; Ueda, Yoshihiro; Ueno, Shiro; Yoshida, Atsumasa

    Monitor of All-sky X-ray Image (MAXI) is an X-ray all-sky monitor in operation now. MAXI GSC and SSC are sensitive in the 2-30 and 0.5-12 keV bands, respectively. On November 11, 2011 (UT), MAXI GSC discovered an unusually luminous and soft X-ray transient, MAXI J0158-744, on the outskirts of the Small Magellanic Cloud (SMC). The outburst lasted for no more than three hours and the luminosity peaked at ˜1040 erg s-1. By the Swift follow-up observation and the optical spectroscopy, we find that the transient was a kind of the nova explosion on a white dwarf in a binary paired with a Be star. We discuss that the outburst can be explained as shock-induced emission caused by a nova explosion in a dense circumstellar medium around a Be star or a photospheric emission on an ignition of a nova explosion. Its fast optical decay (t2 = 1.9 ± 0.2 days) and extremely early turn-on (<0.44 days) of the super-soft X-ray phase suggest that the white dwarf is very massive.

  8. Absolute pulse energy measurements of soft x-rays at the Linac Coherent Light Source.

    PubMed

    Tiedtke, K; Sorokin, A A; Jastrow, U; Juranić, P; Kreis, S; Gerken, N; Richter, M; Arp, U; Feng, Y; Nordlund, D; Soufli, R; Fernández-Perea, M; Juha, L; Heimann, P; Nagler, B; Lee, H J; Mack, S; Cammarata, M; Krupin, O; Messerschmidt, M; Holmes, M; Rowen, M; Schlotter, W; Moeller, S; Turner, J J

    2014-09-01

    This paper reports novel measurements of x-ray optical radiation on an absolute scale from the intense and ultra-short radiation generated in the soft x-ray regime of a free electron laser. We give a brief description of the detection principle for radiation measurements which was specifically adapted for this photon energy range. We present data characterizing the soft x-ray instrument at the Linac Coherent Light Source (LCLS) with respect to the radiant power output and transmission by using an absolute detector temporarily placed at the downstream end of the instrument. This provides an estimation of the reflectivity of all x-ray optical elements in the beamline and provides the absolute photon number per bandwidth per pulse. This parameter is important for many experiments that need to understand the trade-offs between high energy resolution and high flux, such as experiments focused on studying materials via resonant processes. Furthermore, the results are compared with the LCLS diagnostic gas detectors to test the limits of linearity, and observations are reported on radiation contamination from spontaneous undulator radiation and higher harmonic content. PMID:25321502

  9. Broad-band soft x-ray diagnostic instruments at the LLNL Novette laser facility

    SciTech Connect

    Tirsell, K.G.; Lee, P.H.Y.; Nilson, D.G.; Medecki, H.

    1983-09-15

    Complementary broad-band instruments have been developed to measure time dependent, absolute soft x-ray spectra at the Lawrence Livermore National Laboratory (LLNL) Nd glass laser irradiation facilities. Absolute flux measurements of x rays emitted from laser-produced plasmas are important for understanding laser absorption and energy transport. We will describe two new 10-channel XRD systems that have been installed at the LLNL Novette facility for use in the 0.15- to 1.5-keV range. Since XRD channel time response is limited by available oscilloscope performance to 120 ps, a soft x-ray streak camera has been developed for better time resolution (20 ps) and greater dynamic range (approx.10/sup 3/) in the same x-ray energy region. Using suitable filters, grazing incidence mirrors, and a gold or cesium-iodide transmission cathode, this streak camera instrument has been installed at Novette to provide one broad and four relatively narrow channels. It can also be used in a single channel, spatially discriminating mode by means of pinhole imaging. The complementary nature of these instruments has been enhanced by locating them in close proximity and matching their channel energy responses. As an example of the use of these instruments, we present results from Novette 2..omega..(0.53 ..mu..m) gold disk irradiations at 1 ns and 10/sup 14/ to 10/sup 15/ W/cm/sup 2/.

  10. 2D X-ray radiography of imploding capsules at the national ignition facility.

    PubMed

    Rygg, J R; Jones, O S; Field, J E; Barrios, M A; Benedetti, L R; Collins, G W; Eder, D C; Edwards, M J; Kline, J L; Kroll, J J; Landen, O L; Ma, T; Pak, A; Peterson, J L; Raman, K; Town, R P J; Bradley, D K

    2014-05-16

    First measurements of the in-flight shape of imploding inertial confinement fusion (ICF) capsules at the National Ignition Facility (NIF) were obtained by using two-dimensional x-ray radiography. The sequence of area-backlit, time-gated pinhole images is analyzed for implosion velocity, low-mode shape and density asymmetries, and the absolute offset and center-of-mass velocity of the capsule shell. The in-flight shell is often observed to be asymmetric even when the concomitant core self-emission is round. A ∼ 15 μm shell asymmetry amplitude of the Y(40) spherical harmonic mode was observed for standard NIF ICF hohlraums at a shell radius of ∼ 200 μm (capsule at ∼ 5× radial compression). This asymmetry is mitigated by a ∼ 10% increase in the hohlraum length. PMID:24877944

  11. Soft x-ray spectroscopic studies of the electronic structure of organic semiconductors

    NASA Astrophysics Data System (ADS)

    Zhang, Yufeng

    Organic semiconductors have several unique properties, different from traditional inorganic semiconductors, such as flexibility and low cost production on a large scale. Potentially, they can be used in several new optoelectronic devices, such as organic solar cells, and organic light-emitting devices (OLEDs) Phthalocyanines (Pc's) are one important type of molecular organic semiconductor. The ease with which a diverse set of cations can bond to the phthalocyanine ligand leads to Pc-based thin films that display a wide variety of optical and electrical properties. In these materials, the ligand has a complex electronic structure in itself, and the introduction of metal cations adds further complexity to the states near the Fermi level (EF) due to the overlap of metal d states with carbon and nitrogen 2p states. In this thesis, the electronic structure of several Pc's has been studied by soft x-ray spectroscopies, such as x-ray photoemission spectroscopy (XPS), x-ray absorption spectroscopy (XAS), and x-ray emission spectroscopy (XES). To avoid potential contamination and beam damage, the large area thin film samples have been prepared in situ by using organic molecular beam deposition (OMBD). The structure of samples were characterized ex situ by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The soft x-ray spectra recorded from stationary samples are found to represent the electronic structure from damaged molecules, which is caused by intense x-ray beams. Continuously translating samples during measurement overcomes this problem. Element, chemical, and symmetry specific occupied and unoccupied partial density of states (PDOS) from Pc's were observed. They show good agreement with density functional theory (DFT) calculations. Studies of potassium doping non-transition metal Pc, fluorinated metal Pc, and metal oxide Pc's show several interesting phenomena, such as variation of molecular symmetry, and charge transfer and d-d* resonant inelastic x-ray

  12. A GPU Simulation Tool for Training and Optimisation in 2D Digital X-Ray Imaging

    PubMed Central

    Gallio, Elena; Rampado, Osvaldo; Gianaria, Elena; Bianchi, Silvio Diego; Ropolo, Roberto

    2015-01-01

    Conventional radiology is performed by means of digital detectors, with various types of technology and different performance in terms of efficiency and image quality. Following the arrival of a new digital detector in a radiology department, all the staff involved should adapt the procedure parameters to the properties of the detector, in order to achieve an optimal result in terms of correct diagnostic information and minimum radiation risks for the patient. The aim of this study was to develop and validate a software capable of simulating a digital X-ray imaging system, using graphics processing unit computing. All radiological image components were implemented in this application: an X-ray tube with primary beam, a virtual patient, noise, scatter radiation, a grid and a digital detector. Three different digital detectors (two digital radiography and a computed radiography systems) were implemented. In order to validate the software, we carried out a quantitative comparison of geometrical and anthropomorphic phantom simulated images with those acquired. In terms of average pixel values, the maximum differences were below 15%, while the noise values were in agreement with a maximum difference of 20%. The relative trends of contrast to noise ratio versus beam energy and intensity were well simulated. Total calculation times were below 3 seconds for clinical images with pixel size of actual dimensions less than 0.2 mm. The application proved to be efficient and realistic. Short calculation times and the accuracy of the results obtained make this software a useful tool for training operators and dose optimisation studies. PMID:26545097

  13. A GPU Simulation Tool for Training and Optimisation in 2D Digital X-Ray Imaging.

    PubMed

    Gallio, Elena; Rampado, Osvaldo; Gianaria, Elena; Bianchi, Silvio Diego; Ropolo, Roberto

    2015-01-01

    Conventional radiology is performed by means of digital detectors, with various types of technology and different performance in terms of efficiency and image quality. Following the arrival of a new digital detector in a radiology department, all the staff involved should adapt the procedure parameters to the properties of the detector, in order to achieve an optimal result in terms of correct diagnostic information and minimum radiation risks for the patient. The aim of this study was to develop and validate a software capable of simulating a digital X-ray imaging system, using graphics processing unit computing. All radiological image components were implemented in this application: an X-ray tube with primary beam, a virtual patient, noise, scatter radiation, a grid and a digital detector. Three different digital detectors (two digital radiography and a computed radiography systems) were implemented. In order to validate the software, we carried out a quantitative comparison of geometrical and anthropomorphic phantom simulated images with those acquired. In terms of average pixel values, the maximum differences were below 15%, while the noise values were in agreement with a maximum difference of 20%. The relative trends of contrast to noise ratio versus beam energy and intensity were well simulated. Total calculation times were below 3 seconds for clinical images with pixel size of actual dimensions less than 0.2 mm. The application proved to be efficient and realistic. Short calculation times and the accuracy of the results obtained make this software a useful tool for training operators and dose optimisation studies. PMID:26545097

  14. A multi-frame soft x-ray pinhole imaging diagnostic for single-shot applications

    SciTech Connect

    Wurden, G. A.; Coffey, S. K.

    2012-10-15

    For high energy density magnetized target fusion experiments at the Air Force Research Laboratory FRCHX machine, obtaining multi-frame soft x-ray images of the field reversed configuration (FRC) plasma as it is being compressed will provide useful dynamics and symmetry information. However, vacuum hardware will be destroyed during the implosion. We have designed a simple in-vacuum pinhole nosecone attachment, fitting onto a Conflat window, coated with 3.2 mg/cm{sup 2} of P-47 phosphor, and covered with a thin 50-nm aluminum reflective overcoat, lens-coupled to a multi-frame Hadland Ultra intensified digital camera. We compare visible and soft x-ray axial images of translating ({approx}200 eV) plasmas in the FRX-L and FRCHX machines in Los Alamos and Albuquerque.

  15. 0.5-keV Soft X-ray attosecond continua

    PubMed Central

    Teichmann, S. M.; Silva, F.; Cousin, S. L.; Hemmer, M.; Biegert, J.

    2016-01-01

    Attosecond light pulses in the extreme ultraviolet have drawn a great deal of attention due to their ability to interrogate electronic dynamics in real time. Nevertheless, to follow charge dynamics and excitations in materials, element selectivity is a prerequisite, which demands such pulses in the soft X-ray region, above 200 eV, to simultaneously cover several fundamental absorption edges of the constituents of the materials. Here, we experimentally demonstrate the exploitation of a transient phase matching regime to generate carrier envelope controlled soft X-ray supercontinua with pulse energies up to 2.9±0.1 pJ and a flux of (7.3±0.1) × 107 photons per second across the entire water window and attosecond pulses with 13 as transform limit. Our results herald attosecond science at the fundamental absorption edges of matter by bridging the gap between ultrafast temporal resolution and element specific probing. PMID:27167525

  16. An extended soft X-ray source in Delphinus - H2027+19

    NASA Technical Reports Server (NTRS)

    Stern, R. A.; Walker, A. B. C.; Charles, P. A.; Nugent, J. J.; Garmire, G. P.

    1980-01-01

    A new extended soft X-ray source has been observed with the HEAO 1 A-2 experiment. The source, H2027+19, emits primarily in the 0.16-0.4 keV band with a total flux in this band of 2 x 10 to the -11th erg/sq cm s. It is found that both simple continuum and coronal plasma models provide good fits to the observed pulse-height spectrum. The most likely physical models are either that the source is an old supernova remnant or that it is a region of enhanced soft X-ray emission surrounding an H I cloud imbedded in a coronal plasma, as suggested by Hayakawa et al. (1979) for the Lupus Loop.

  17. Large-area avalanche photodiodes for the detection of soft x rays

    SciTech Connect

    Gullikson, E.M.; Gramsch, E. |; Szawlowski, M.

    1995-08-01

    The charge-collection efficiency of beveled-edge-type silicon avalanche photodiodes has been determined for soft x rays in the 50--300-eV range. An efficiency of greater than 80% is measured for energies below the Si {ital L} absorption edge. The measured efficiency is well described by a model that accounts for absorption in an oxide overlayer and recombination at the front surface of the diode. The avalanche photodiodes are shown to be significantly more sensitive compared with other detectors for pulsed sources such as a laser-produced plasma source. These results are also very encouraging for soft-x-ray/extreme-UV applications involving synchrotron radiation.{ital PACS} {ital numbers}: 29.40.Wk, 07.85.+n, 85.60.Dw.

  18. Molecular bond selective x-ray scattering for nanoscale analysisof soft matter

    SciTech Connect

    Mitchell, G.E.; Koprinarov, I.; Landes, B.G.; Lyons, J.; Kern,B.J.; Devon, M.J.; Gullikson, E.M.; Kortright, J.B.

    2005-05-26

    We introduce a new technique using resonant soft x-ray scattering for characterizing heterogeneous chemical structure at nanometer length scales in polymers, biological material, and other soft matter. Resonant enhancements bring new contrast mechanisms and increased sensitivity to bridge a gap between bond-specific contrast in chemical sensitive imaging and the higher spatial resolution of traditional small-angle scattering techniques. We illustrate sensitivity to chemical bonding with the resonant scattering near the carbon K edge from latex spheres of differing chemistry and sizes. By tuning to x-ray absorption resonances associated with particular carbon-carbon or carbon-oxygen bonds we can isolate the scattering from different phases in a 2-phase mixture. We then illustrate this increased scattering contrast with a study of the templating process to form nanometer scale pores in 100 nm thick polymer films.

  19. Soft x-ray camera for internal shape and current density measurements on a noncircular tokamak

    SciTech Connect

    Fonck, R.J.; Jaehnig, K.P.; Powell, E.T.; Reusch, M.; Roney, P.; Simon, M.P.

    1988-05-01

    Soft x-ray measurements of the internal plasma flux surface shaped in principle allow a determination of the plasma current density distribution, and provide a necessary monitor of the degree of internal elongation of tokamak plasmas with a noncircular cross section. A two-dimensional, tangentially viewing, soft x-ray pinhole camera has been fabricated to provide internal shape measurements on the PBX-M tokamak. It consists of a scintillator at the focal plane of a foil-filtered pinhole camera, which is, in turn, fiber optically coupled to an intensified framing video camera (/DELTA/t />=/ 3 msec). Automated data acquisition is performed on a stand-alone image-processing system, and data archiving and retrieval takes place on an optical disk video recorder. The entire diagnostic is controlled via a PDP-11/73 microcomputer. The derivation of the polodial emission distribution from the measured image is done by fitting to model profiles. 10 refs., 4 figs.

  20. A Soft X-Ray Imager for the Space Weather Applications

    NASA Astrophysics Data System (ADS)

    Sibeck, D. G.; Collier, M. R.; Connor, H.; Kuntz, K. D.; Porter, S.; Walsh, B.

    2014-12-01

    Global measurements are needed to assess the state of the solar wind-magnetosphere interaction and validate the predictions of space weather models. Since all of the solar wind mass, energy, and momentum that powers geomagnetic storms and substorms flows through the dayside magnetosheath and cusps, observations of the locations and nature of the bow shock, magnetopause, and cusp, as well as the characteristics of the magnetosheath are key to this effort. Fortunately, charge exchange between solar wind ions and exospheric neutrals in all of these regions emits soft x-rays. Here we describe our efforts to (1) develop a wide field of view soft x-ray imager capable of imaging the density structures that characterize this region of space and (2) extracting meaningful science from the images so obtained.